Searched +hist:4 +hist:f193362 (Results 1 - 13 of 13) sorted by relevance
/linux-master/arch/arm/boot/bootp/ | ||
H A D | Makefile | diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff 4f193362 Sun Mar 05 15:14:10 MST 2006 Paul Smith <psmith@gnu.org> kbuild: change kbuild to not rely on incorrect GNU make behavior The kbuild system takes advantage of an incorrect behavior in GNU make. Once this behavior is fixed, all files in the kernel rebuild every time, even if nothing has changed. This patch ensures kbuild works with both the incorrect and correct behaviors of GNU make. For more details on the incorrect behavior, see: http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html Changes in this patch: - Keep all targets that are to be marked .PHONY in a variable, PHONY. - Add .PHONY: $(PHONY) to mark them properly. - Remove any $(PHONY) files from the $? list when determining whether targets are up-to-date or not. Signed-off-by: Paul Smith <psmith@gnu.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> diff 4f193362 Sun Mar 05 15:14:10 MST 2006 Paul Smith <psmith@gnu.org> kbuild: change kbuild to not rely on incorrect GNU make behavior The kbuild system takes advantage of an incorrect behavior in GNU make. Once this behavior is fixed, all files in the kernel rebuild every time, even if nothing has changed. This patch ensures kbuild works with both the incorrect and correct behaviors of GNU make. For more details on the incorrect behavior, see: http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html Changes in this patch: - Keep all targets that are to be marked .PHONY in a variable, PHONY. - Add .PHONY: $(PHONY) to mark them properly. - Remove any $(PHONY) files from the $? list when determining whether targets are up-to-date or not. Signed-off-by: Paul Smith <psmith@gnu.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> |
/linux-master/scripts/ | ||
H A D | Makefile.clean | diff 4ca76945 Sat Aug 24 19:31:39 MDT 2019 Masahiro Yamada <yamada.masahiro@socionext.com> kbuild: clean up subdir-ymn calculation in Makefile.clean Remove some variables. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff 4f193362 Sun Mar 05 15:14:10 MST 2006 Paul Smith <psmith@gnu.org> kbuild: change kbuild to not rely on incorrect GNU make behavior The kbuild system takes advantage of an incorrect behavior in GNU make. Once this behavior is fixed, all files in the kernel rebuild every time, even if nothing has changed. This patch ensures kbuild works with both the incorrect and correct behaviors of GNU make. For more details on the incorrect behavior, see: http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html Changes in this patch: - Keep all targets that are to be marked .PHONY in a variable, PHONY. - Add .PHONY: $(PHONY) to mark them properly. - Remove any $(PHONY) files from the $? list when determining whether targets are up-to-date or not. Signed-off-by: Paul Smith <psmith@gnu.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> diff 4f193362 Sun Mar 05 15:14:10 MST 2006 Paul Smith <psmith@gnu.org> kbuild: change kbuild to not rely on incorrect GNU make behavior The kbuild system takes advantage of an incorrect behavior in GNU make. Once this behavior is fixed, all files in the kernel rebuild every time, even if nothing has changed. This patch ensures kbuild works with both the incorrect and correct behaviors of GNU make. For more details on the incorrect behavior, see: http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html Changes in this patch: - Keep all targets that are to be marked .PHONY in a variable, PHONY. - Add .PHONY: $(PHONY) to mark them properly. - Remove any $(PHONY) files from the $? list when determining whether targets are up-to-date or not. Signed-off-by: Paul Smith <psmith@gnu.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> |
H A D | Makefile.modinst | diff 22e46f64 Tue Jan 31 01:43:23 MST 2023 Jan Luebbe <jlu@pengutronix.de> kbuild: modinst: Fix build error when CONFIG_MODULE_SIG_KEY is a PKCS#11 URI When CONFIG_MODULE_SIG_KEY is PKCS#11 URI (pkcs11:*), signing of modules fails: scripts/sign-file sha256 /.../linux/pkcs11:token=foo;object=bar;pin-value=1111 certs/signing_key.x509 /.../kernel/crypto/tcrypt.ko Usage: scripts/sign-file [-dp] <hash algo> <key> <x509> <module> [<dest>] scripts/sign-file -s <raw sig> <hash algo> <x509> <module> [<dest>] First, we need to avoid adding the $(srctree)/ prefix to the URL. Second, since the kconfig string values no longer include quotes, we need to add them again when passing a PKCS#11 URI to sign-file. This avoids splitting by the shell if the URI contains semicolons. Fixes: 4db9c2e3d055 ("kbuild: stop using config_filename in scripts/Makefile.modsign") Fixes: 129ab0d2d9f3 ("kbuild: do not quote string values in include/config/auto.conf") Signed-off-by: Jan Luebbe <jlu@pengutronix.de> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 129ab0d2 Mon Dec 13 19:53:53 MST 2021 Masahiro Yamada <masahiroy@kernel.org> kbuild: do not quote string values in include/config/auto.conf The previous commit fixed up all shell scripts to not include include/config/auto.conf. Now that include/config/auto.conf is only included by Makefiles, we can change it into a more Make-friendly form. Previously, Kconfig output string values enclosed with double-quotes (both in the .config and include/config/auto.conf): CONFIG_X="foo bar" Unlike shell, Make handles double-quotes (and single-quotes as well) verbatim. We must rip them off when used. There are some patterns: [1] $(patsubst "%",%,$(CONFIG_X)) [2] $(CONFIG_X:"%"=%) [3] $(subst ",,$(CONFIG_X)) [4] $(shell echo $(CONFIG_X)) These are not only ugly, but also fragile. [1] and [2] do not work if the value contains spaces, like CONFIG_X=" foo bar " [3] does not work correctly if the value contains double-quotes like CONFIG_X="foo\"bar" [4] seems to work better, but has a cost of forking a process. Anyway, quoted strings were always PITA for our Makefiles. This commit changes Kconfig to stop quoting in include/config/auto.conf. These are the string type symbols referenced in Makefiles or scripts: ACPI_CUSTOM_DSDT_FILE ARC_BUILTIN_DTB_NAME ARC_TUNE_MCPU BUILTIN_DTB_SOURCE CC_IMPLICIT_FALLTHROUGH CC_VERSION_TEXT CFG80211_EXTRA_REGDB_KEYDIR EXTRA_FIRMWARE EXTRA_FIRMWARE_DIR EXTRA_TARGETS H8300_BUILTIN_DTB INITRAMFS_SOURCE LOCALVERSION MODULE_SIG_HASH MODULE_SIG_KEY NDS32_BUILTIN_DTB NIOS2_DTB_SOURCE OPENRISC_BUILTIN_DTB SOC_CANAAN_K210_DTB_SOURCE SYSTEM_BLACKLIST_HASH_LIST SYSTEM_REVOCATION_KEYS SYSTEM_TRUSTED_KEYS TARGET_CPU UNUSED_KSYMS_WHITELIST XILINX_MICROBLAZE0_FAMILY XILINX_MICROBLAZE0_HW_VER XTENSA_VARIANT_NAME I checked them one by one, and fixed up the code where necessary. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 129ab0d2 Mon Dec 13 19:53:53 MST 2021 Masahiro Yamada <masahiroy@kernel.org> kbuild: do not quote string values in include/config/auto.conf The previous commit fixed up all shell scripts to not include include/config/auto.conf. Now that include/config/auto.conf is only included by Makefiles, we can change it into a more Make-friendly form. Previously, Kconfig output string values enclosed with double-quotes (both in the .config and include/config/auto.conf): CONFIG_X="foo bar" Unlike shell, Make handles double-quotes (and single-quotes as well) verbatim. We must rip them off when used. There are some patterns: [1] $(patsubst "%",%,$(CONFIG_X)) [2] $(CONFIG_X:"%"=%) [3] $(subst ",,$(CONFIG_X)) [4] $(shell echo $(CONFIG_X)) These are not only ugly, but also fragile. [1] and [2] do not work if the value contains spaces, like CONFIG_X=" foo bar " [3] does not work correctly if the value contains double-quotes like CONFIG_X="foo\"bar" [4] seems to work better, but has a cost of forking a process. Anyway, quoted strings were always PITA for our Makefiles. This commit changes Kconfig to stop quoting in include/config/auto.conf. These are the string type symbols referenced in Makefiles or scripts: ACPI_CUSTOM_DSDT_FILE ARC_BUILTIN_DTB_NAME ARC_TUNE_MCPU BUILTIN_DTB_SOURCE CC_IMPLICIT_FALLTHROUGH CC_VERSION_TEXT CFG80211_EXTRA_REGDB_KEYDIR EXTRA_FIRMWARE EXTRA_FIRMWARE_DIR EXTRA_TARGETS H8300_BUILTIN_DTB INITRAMFS_SOURCE LOCALVERSION MODULE_SIG_HASH MODULE_SIG_KEY NDS32_BUILTIN_DTB NIOS2_DTB_SOURCE OPENRISC_BUILTIN_DTB SOC_CANAAN_K210_DTB_SOURCE SYSTEM_BLACKLIST_HASH_LIST SYSTEM_REVOCATION_KEYS SYSTEM_TRUSTED_KEYS TARGET_CPU UNUSED_KSYMS_WHITELIST XILINX_MICROBLAZE0_FAMILY XILINX_MICROBLAZE0_HW_VER XTENSA_VARIANT_NAME I checked them one by one, and fixed up the code where necessary. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 4db9c2e3 Mon Dec 13 19:53:50 MST 2021 Masahiro Yamada <masahiroy@kernel.org> kbuild: stop using config_filename in scripts/Makefile.modsign Toward the goal of removing the config_filename macro, drop the double-quotes and add $(srctree)/ prefix in an ad hoc way. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de> diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff 4f193362 Sun Mar 05 15:14:10 MST 2006 Paul Smith <psmith@gnu.org> kbuild: change kbuild to not rely on incorrect GNU make behavior The kbuild system takes advantage of an incorrect behavior in GNU make. Once this behavior is fixed, all files in the kernel rebuild every time, even if nothing has changed. This patch ensures kbuild works with both the incorrect and correct behaviors of GNU make. For more details on the incorrect behavior, see: http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html Changes in this patch: - Keep all targets that are to be marked .PHONY in a variable, PHONY. - Add .PHONY: $(PHONY) to mark them properly. - Remove any $(PHONY) files from the $? list when determining whether targets are up-to-date or not. Signed-off-by: Paul Smith <psmith@gnu.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> diff 4f193362 Sun Mar 05 15:14:10 MST 2006 Paul Smith <psmith@gnu.org> kbuild: change kbuild to not rely on incorrect GNU make behavior The kbuild system takes advantage of an incorrect behavior in GNU make. Once this behavior is fixed, all files in the kernel rebuild every time, even if nothing has changed. This patch ensures kbuild works with both the incorrect and correct behaviors of GNU make. For more details on the incorrect behavior, see: http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html Changes in this patch: - Keep all targets that are to be marked .PHONY in a variable, PHONY. - Add .PHONY: $(PHONY) to mark them properly. - Remove any $(PHONY) files from the $? list when determining whether targets are up-to-date or not. Signed-off-by: Paul Smith <psmith@gnu.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> |
H A D | Makefile.modpost | diff f73edc89 Sat Sep 24 12:19:13 MDT 2022 Masahiro Yamada <masahiroy@kernel.org> kbuild: unify two modpost invocations Currently, modpost is executed twice; first for vmlinux, second for modules. This commit merges them. Current build flow ================== 1) build obj-y and obj-m objects 2) link vmlinux.o 3) modpost for vmlinux 4) link vmlinux 5) modpost for modules 6) link modules (*.ko) The build steps 1) through 6) are serialized, that is, modules are built after vmlinux. You do not get benefits of parallel builds when scripts/link-vmlinux.sh is being run. New build flow ============== 1) build obj-y and obj-m objects 2) link vmlinux.o 3) modpost for vmlinux and modules 4a) link vmlinux 4b) link modules (*.ko) In the new build flow, modpost is invoked just once. vmlinux and modules are built in parallel. One exception is CONFIG_DEBUG_INFO_BTF_MODULES=y, where modules depend on vmlinux. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> diff f73edc89 Sat Sep 24 12:19:13 MDT 2022 Masahiro Yamada <masahiroy@kernel.org> kbuild: unify two modpost invocations Currently, modpost is executed twice; first for vmlinux, second for modules. This commit merges them. Current build flow ================== 1) build obj-y and obj-m objects 2) link vmlinux.o 3) modpost for vmlinux 4) link vmlinux 5) modpost for modules 6) link modules (*.ko) The build steps 1) through 6) are serialized, that is, modules are built after vmlinux. You do not get benefits of parallel builds when scripts/link-vmlinux.sh is being run. New build flow ============== 1) build obj-y and obj-m objects 2) link vmlinux.o 3) modpost for vmlinux and modules 4a) link vmlinux 4b) link modules (*.ko) In the new build flow, modpost is invoked just once. vmlinux and modules are built in parallel. One exception is CONFIG_DEBUG_INFO_BTF_MODULES=y, where modules depend on vmlinux. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> diff f73edc89 Sat Sep 24 12:19:13 MDT 2022 Masahiro Yamada <masahiroy@kernel.org> kbuild: unify two modpost invocations Currently, modpost is executed twice; first for vmlinux, second for modules. This commit merges them. Current build flow ================== 1) build obj-y and obj-m objects 2) link vmlinux.o 3) modpost for vmlinux 4) link vmlinux 5) modpost for modules 6) link modules (*.ko) The build steps 1) through 6) are serialized, that is, modules are built after vmlinux. You do not get benefits of parallel builds when scripts/link-vmlinux.sh is being run. New build flow ============== 1) build obj-y and obj-m objects 2) link vmlinux.o 3) modpost for vmlinux and modules 4a) link vmlinux 4b) link modules (*.ko) In the new build flow, modpost is invoked just once. vmlinux and modules are built in parallel. One exception is CONFIG_DEBUG_INFO_BTF_MODULES=y, where modules depend on vmlinux. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> diff 38e89184 Fri Dec 11 11:46:20 MST 2020 Sami Tolvanen <samitolvanen@google.com> kbuild: lto: fix module versioning With CONFIG_MODVERSIONS, version information is linked into each compilation unit that exports symbols. With LTO, we cannot use this method as all C code is compiled into LLVM bitcode instead. This change collects symbol versions into .symversions files and merges them in link-vmlinux.sh where they are all linked into vmlinux.o at the same time. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201211184633.3213045-4-samitolvanen@google.com diff 4e5ab74c Sun May 31 23:57:03 MDT 2020 Masahiro Yamada <masahiroy@kernel.org> modpost: pass -N option only for modules modpost The built-in only code is not required to have MODULE_IMPORT_NS() to use symbols. So, the namespace is not checked for vmlinux(.o). Do not pass the meaningless -N option to the first pass of modpost. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 91e6ee58 Sun May 31 23:57:01 MDT 2020 Masahiro Yamada <masahiroy@kernel.org> modpost: fix -i (--ignore-errors) MAKEFLAGS detection $(filter -i,$(MAKEFLAGS)) works only in limited use-cases. The representation of $(MAKEFLAGS) depends on various factors: - GNU Make version (version 3.8x or version 4.x) - The presence of other flags like -j In my experiments, $(MAKEFLAGS) is expanded as follows: * GNU Make 3.8x: * without -j option: --no-print-directory -Rri * with -j option: --no-print-directory -Rr --jobserver-fds=3,4 -j -i * GNU Make 4.x: * without -j option: irR --no-print-directory * with -j option: irR -j --jobserver-fds=3,4 --no-print-directory For GNU Make 4.x, the flags are grouped as 'irR', which does not work. For the single thread build with GNU Make 3.8x, the flags are grouped as '-Rri', which does not work either. To make it work for all cases, do likewise as commit 6f0fa58e4596 ("kbuild: simplify silent build (-s) detection"). BTW, since commit ff9b45c55b26 ("kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod"), you also need to pass -k option to build final *.ko files. 'make -i -k' ignores compile errors in modules, and build as many remaining *.ko as possible. Please note this feature is kind of dangerous if other modules depend on the broken module because the generated modules will lack the correct module dependency or CRC. Honestly, I am not a big fan of it, but I am keeping this feature. Fixes: eed380f3f593 ("modpost: Optionally ignore secondary errors seen if a single module build fails") Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 91e6ee58 Sun May 31 23:57:01 MDT 2020 Masahiro Yamada <masahiroy@kernel.org> modpost: fix -i (--ignore-errors) MAKEFLAGS detection $(filter -i,$(MAKEFLAGS)) works only in limited use-cases. The representation of $(MAKEFLAGS) depends on various factors: - GNU Make version (version 3.8x or version 4.x) - The presence of other flags like -j In my experiments, $(MAKEFLAGS) is expanded as follows: * GNU Make 3.8x: * without -j option: --no-print-directory -Rri * with -j option: --no-print-directory -Rr --jobserver-fds=3,4 -j -i * GNU Make 4.x: * without -j option: irR --no-print-directory * with -j option: irR -j --jobserver-fds=3,4 --no-print-directory For GNU Make 4.x, the flags are grouped as 'irR', which does not work. For the single thread build with GNU Make 3.8x, the flags are grouped as '-Rri', which does not work either. To make it work for all cases, do likewise as commit 6f0fa58e4596 ("kbuild: simplify silent build (-s) detection"). BTW, since commit ff9b45c55b26 ("kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod"), you also need to pass -k option to build final *.ko files. 'make -i -k' ignores compile errors in modules, and build as many remaining *.ko as possible. Please note this feature is kind of dangerous if other modules depend on the broken module because the generated modules will lack the correct module dependency or CRC. Honestly, I am not a big fan of it, but I am keeping this feature. Fixes: eed380f3f593 ("modpost: Optionally ignore secondary errors seen if a single module build fails") Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 91e6ee58 Sun May 31 23:57:01 MDT 2020 Masahiro Yamada <masahiroy@kernel.org> modpost: fix -i (--ignore-errors) MAKEFLAGS detection $(filter -i,$(MAKEFLAGS)) works only in limited use-cases. The representation of $(MAKEFLAGS) depends on various factors: - GNU Make version (version 3.8x or version 4.x) - The presence of other flags like -j In my experiments, $(MAKEFLAGS) is expanded as follows: * GNU Make 3.8x: * without -j option: --no-print-directory -Rri * with -j option: --no-print-directory -Rr --jobserver-fds=3,4 -j -i * GNU Make 4.x: * without -j option: irR --no-print-directory * with -j option: irR -j --jobserver-fds=3,4 --no-print-directory For GNU Make 4.x, the flags are grouped as 'irR', which does not work. For the single thread build with GNU Make 3.8x, the flags are grouped as '-Rri', which does not work either. To make it work for all cases, do likewise as commit 6f0fa58e4596 ("kbuild: simplify silent build (-s) detection"). BTW, since commit ff9b45c55b26 ("kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod"), you also need to pass -k option to build final *.ko files. 'make -i -k' ignores compile errors in modules, and build as many remaining *.ko as possible. Please note this feature is kind of dangerous if other modules depend on the broken module because the generated modules will lack the correct module dependency or CRC. Honestly, I am not a big fan of it, but I am keeping this feature. Fixes: eed380f3f593 ("modpost: Optionally ignore secondary errors seen if a single module build fails") Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 91e6ee58 Sun May 31 23:57:01 MDT 2020 Masahiro Yamada <masahiroy@kernel.org> modpost: fix -i (--ignore-errors) MAKEFLAGS detection $(filter -i,$(MAKEFLAGS)) works only in limited use-cases. The representation of $(MAKEFLAGS) depends on various factors: - GNU Make version (version 3.8x or version 4.x) - The presence of other flags like -j In my experiments, $(MAKEFLAGS) is expanded as follows: * GNU Make 3.8x: * without -j option: --no-print-directory -Rri * with -j option: --no-print-directory -Rr --jobserver-fds=3,4 -j -i * GNU Make 4.x: * without -j option: irR --no-print-directory * with -j option: irR -j --jobserver-fds=3,4 --no-print-directory For GNU Make 4.x, the flags are grouped as 'irR', which does not work. For the single thread build with GNU Make 3.8x, the flags are grouped as '-Rri', which does not work either. To make it work for all cases, do likewise as commit 6f0fa58e4596 ("kbuild: simplify silent build (-s) detection"). BTW, since commit ff9b45c55b26 ("kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod"), you also need to pass -k option to build final *.ko files. 'make -i -k' ignores compile errors in modules, and build as many remaining *.ko as possible. Please note this feature is kind of dangerous if other modules depend on the broken module because the generated modules will lack the correct module dependency or CRC. Honestly, I am not a big fan of it, but I am keeping this feature. Fixes: eed380f3f593 ("modpost: Optionally ignore secondary errors seen if a single module build fails") Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 91e6ee58 Sun May 31 23:57:01 MDT 2020 Masahiro Yamada <masahiroy@kernel.org> modpost: fix -i (--ignore-errors) MAKEFLAGS detection $(filter -i,$(MAKEFLAGS)) works only in limited use-cases. The representation of $(MAKEFLAGS) depends on various factors: - GNU Make version (version 3.8x or version 4.x) - The presence of other flags like -j In my experiments, $(MAKEFLAGS) is expanded as follows: * GNU Make 3.8x: * without -j option: --no-print-directory -Rri * with -j option: --no-print-directory -Rr --jobserver-fds=3,4 -j -i * GNU Make 4.x: * without -j option: irR --no-print-directory * with -j option: irR -j --jobserver-fds=3,4 --no-print-directory For GNU Make 4.x, the flags are grouped as 'irR', which does not work. For the single thread build with GNU Make 3.8x, the flags are grouped as '-Rri', which does not work either. To make it work for all cases, do likewise as commit 6f0fa58e4596 ("kbuild: simplify silent build (-s) detection"). BTW, since commit ff9b45c55b26 ("kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod"), you also need to pass -k option to build final *.ko files. 'make -i -k' ignores compile errors in modules, and build as many remaining *.ko as possible. Please note this feature is kind of dangerous if other modules depend on the broken module because the generated modules will lack the correct module dependency or CRC. Honestly, I am not a big fan of it, but I am keeping this feature. Fixes: eed380f3f593 ("modpost: Optionally ignore secondary errors seen if a single module build fails") Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> |
H A D | Kbuild.include | diff a7f3257d Sat Aug 06 18:48:09 MDT 2022 Masahiro Yamada <masahiroy@kernel.org> kbuild: remove the target in signal traps when interrupted When receiving some signal, GNU Make automatically deletes the target if it has already been changed by the interrupted recipe. If the target is possibly incomplete due to interruption, it must be deleted so that it will be remade from scratch on the next run of make. Otherwise, the target would remain corrupted permanently because its timestamp had already been updated. Thanks to this behavior of Make, you can stop the build any time by pressing Ctrl-C, and just run 'make' to resume it. Kbuild also relies on this feature, but it is equivalently important for any build systems that make decisions based on timestamps (if you want to support Ctrl-C reliably). However, this does not always work as claimed; Make immediately dies with Ctrl-C if its stderr goes into a pipe. [Test Makefile] foo: echo hello > $@ sleep 3 echo world >> $@ [Test Result] $ make # hit Ctrl-C echo hello > foo sleep 3 ^Cmake: *** Deleting file 'foo' make: *** [Makefile:3: foo] Interrupt $ make 2>&1 | cat # hit Ctrl-C echo hello > foo sleep 3 ^C$ # 'foo' is often left-over The reason is because SIGINT is sent to the entire process group. In this example, SIGINT kills 'cat', and 'make' writes the message to the closed pipe, then dies with SIGPIPE before cleaning the target. A typical bad scenario (as reported by [1], [2]) is to save build log by using the 'tee' command: $ make 2>&1 | tee log This can be problematic for any build systems based on Make, so I hope it will be fixed in GNU Make. The maintainer of GNU Make stated this is a long-standing issue and difficult to fix [3]. It has not been fixed yet as of writing. So, we cannot rely on Make cleaning the target. We can do it by ourselves, in signal traps. As far as I understand, Make takes care of SIGHUP, SIGINT, SIGQUIT, and SITERM for the target removal. I added the traps for them, and also for SIGPIPE just in case cmd_* rule prints something to stdout or stderr (but I did not observe an actual case where SIGPIPE was triggered). [Note 1] The trap handler might be worth explaining. rm -f $@; trap - $(sig); kill -s $(sig) $$ This lets the shell kill itself by the signal it caught, so the parent process can tell the child has exited on the signal. Generally, this is a proper manner for handling signals, in case the calling program (like Bash) may monitor WIFSIGNALED() and WTERMSIG() for WCE although this may not be a big deal here because GNU Make handles SIGHUP, SIGINT, SIGQUIT in WUE and SIGTERM in IUE. IUE - Immediate Unconditional Exit WUE - Wait and Unconditional Exit WCE - Wait and Cooperative Exit For details, see "Proper handling of SIGINT/SIGQUIT" [4]. [Note 2] Reverting 392885ee82d3 ("kbuild: let fixdep directly write to .*.cmd files") would directly address [1], but it only saves if_changed_dep. As reported in [2], all commands that use redirection can potentially leave an empty (i.e. broken) target. [Note 3] Another (even safer) approach might be to always write to a temporary file, and rename it to $@ at the end of the recipe. <command> > $(tmp-target) mv $(tmp-target) $@ It would require a lot of Makefile changes, and result in ugly code, so I did not take it. [Note 4] A little more thoughts about a pattern rule with multiple targets (or a grouped target). %.x %.y: %.z <recipe> When interrupted, GNU Make deletes both %.x and %.y, while this solution only deletes $@. Probably, this is not a big deal. The next run of make will execute the rule again to create $@ along with the other files. [1]: https://lore.kernel.org/all/YLeot94yAaM4xbMY@gmail.com/ [2]: https://lore.kernel.org/all/20220510221333.2770571-1-robh@kernel.org/ [3]: https://lists.gnu.org/archive/html/help-make/2021-06/msg00001.html [4]: https://www.cons.org/cracauer/sigint.html Fixes: 392885ee82d3 ("kbuild: let fixdep directly write to .*.cmd files") Reported-by: Ingo Molnar <mingo@kernel.org> Reported-by: Rob Herring <robh@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> diff a7f3257d Sat Aug 06 18:48:09 MDT 2022 Masahiro Yamada <masahiroy@kernel.org> kbuild: remove the target in signal traps when interrupted When receiving some signal, GNU Make automatically deletes the target if it has already been changed by the interrupted recipe. If the target is possibly incomplete due to interruption, it must be deleted so that it will be remade from scratch on the next run of make. Otherwise, the target would remain corrupted permanently because its timestamp had already been updated. Thanks to this behavior of Make, you can stop the build any time by pressing Ctrl-C, and just run 'make' to resume it. Kbuild also relies on this feature, but it is equivalently important for any build systems that make decisions based on timestamps (if you want to support Ctrl-C reliably). However, this does not always work as claimed; Make immediately dies with Ctrl-C if its stderr goes into a pipe. [Test Makefile] foo: echo hello > $@ sleep 3 echo world >> $@ [Test Result] $ make # hit Ctrl-C echo hello > foo sleep 3 ^Cmake: *** Deleting file 'foo' make: *** [Makefile:3: foo] Interrupt $ make 2>&1 | cat # hit Ctrl-C echo hello > foo sleep 3 ^C$ # 'foo' is often left-over The reason is because SIGINT is sent to the entire process group. In this example, SIGINT kills 'cat', and 'make' writes the message to the closed pipe, then dies with SIGPIPE before cleaning the target. A typical bad scenario (as reported by [1], [2]) is to save build log by using the 'tee' command: $ make 2>&1 | tee log This can be problematic for any build systems based on Make, so I hope it will be fixed in GNU Make. The maintainer of GNU Make stated this is a long-standing issue and difficult to fix [3]. It has not been fixed yet as of writing. So, we cannot rely on Make cleaning the target. We can do it by ourselves, in signal traps. As far as I understand, Make takes care of SIGHUP, SIGINT, SIGQUIT, and SITERM for the target removal. I added the traps for them, and also for SIGPIPE just in case cmd_* rule prints something to stdout or stderr (but I did not observe an actual case where SIGPIPE was triggered). [Note 1] The trap handler might be worth explaining. rm -f $@; trap - $(sig); kill -s $(sig) $$ This lets the shell kill itself by the signal it caught, so the parent process can tell the child has exited on the signal. Generally, this is a proper manner for handling signals, in case the calling program (like Bash) may monitor WIFSIGNALED() and WTERMSIG() for WCE although this may not be a big deal here because GNU Make handles SIGHUP, SIGINT, SIGQUIT in WUE and SIGTERM in IUE. IUE - Immediate Unconditional Exit WUE - Wait and Unconditional Exit WCE - Wait and Cooperative Exit For details, see "Proper handling of SIGINT/SIGQUIT" [4]. [Note 2] Reverting 392885ee82d3 ("kbuild: let fixdep directly write to .*.cmd files") would directly address [1], but it only saves if_changed_dep. As reported in [2], all commands that use redirection can potentially leave an empty (i.e. broken) target. [Note 3] Another (even safer) approach might be to always write to a temporary file, and rename it to $@ at the end of the recipe. <command> > $(tmp-target) mv $(tmp-target) $@ It would require a lot of Makefile changes, and result in ugly code, so I did not take it. [Note 4] A little more thoughts about a pattern rule with multiple targets (or a grouped target). %.x %.y: %.z <recipe> When interrupted, GNU Make deletes both %.x and %.y, while this solution only deletes $@. Probably, this is not a big deal. The next run of make will execute the rule again to create $@ along with the other files. [1]: https://lore.kernel.org/all/YLeot94yAaM4xbMY@gmail.com/ [2]: https://lore.kernel.org/all/20220510221333.2770571-1-robh@kernel.org/ [3]: https://lists.gnu.org/archive/html/help-make/2021-06/msg00001.html [4]: https://www.cons.org/cracauer/sigint.html Fixes: 392885ee82d3 ("kbuild: let fixdep directly write to .*.cmd files") Reported-by: Ingo Molnar <mingo@kernel.org> Reported-by: Rob Herring <robh@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> diff a7f3257d Sat Aug 06 18:48:09 MDT 2022 Masahiro Yamada <masahiroy@kernel.org> kbuild: remove the target in signal traps when interrupted When receiving some signal, GNU Make automatically deletes the target if it has already been changed by the interrupted recipe. If the target is possibly incomplete due to interruption, it must be deleted so that it will be remade from scratch on the next run of make. Otherwise, the target would remain corrupted permanently because its timestamp had already been updated. Thanks to this behavior of Make, you can stop the build any time by pressing Ctrl-C, and just run 'make' to resume it. Kbuild also relies on this feature, but it is equivalently important for any build systems that make decisions based on timestamps (if you want to support Ctrl-C reliably). However, this does not always work as claimed; Make immediately dies with Ctrl-C if its stderr goes into a pipe. [Test Makefile] foo: echo hello > $@ sleep 3 echo world >> $@ [Test Result] $ make # hit Ctrl-C echo hello > foo sleep 3 ^Cmake: *** Deleting file 'foo' make: *** [Makefile:3: foo] Interrupt $ make 2>&1 | cat # hit Ctrl-C echo hello > foo sleep 3 ^C$ # 'foo' is often left-over The reason is because SIGINT is sent to the entire process group. In this example, SIGINT kills 'cat', and 'make' writes the message to the closed pipe, then dies with SIGPIPE before cleaning the target. A typical bad scenario (as reported by [1], [2]) is to save build log by using the 'tee' command: $ make 2>&1 | tee log This can be problematic for any build systems based on Make, so I hope it will be fixed in GNU Make. The maintainer of GNU Make stated this is a long-standing issue and difficult to fix [3]. It has not been fixed yet as of writing. So, we cannot rely on Make cleaning the target. We can do it by ourselves, in signal traps. As far as I understand, Make takes care of SIGHUP, SIGINT, SIGQUIT, and SITERM for the target removal. I added the traps for them, and also for SIGPIPE just in case cmd_* rule prints something to stdout or stderr (but I did not observe an actual case where SIGPIPE was triggered). [Note 1] The trap handler might be worth explaining. rm -f $@; trap - $(sig); kill -s $(sig) $$ This lets the shell kill itself by the signal it caught, so the parent process can tell the child has exited on the signal. Generally, this is a proper manner for handling signals, in case the calling program (like Bash) may monitor WIFSIGNALED() and WTERMSIG() for WCE although this may not be a big deal here because GNU Make handles SIGHUP, SIGINT, SIGQUIT in WUE and SIGTERM in IUE. IUE - Immediate Unconditional Exit WUE - Wait and Unconditional Exit WCE - Wait and Cooperative Exit For details, see "Proper handling of SIGINT/SIGQUIT" [4]. [Note 2] Reverting 392885ee82d3 ("kbuild: let fixdep directly write to .*.cmd files") would directly address [1], but it only saves if_changed_dep. As reported in [2], all commands that use redirection can potentially leave an empty (i.e. broken) target. [Note 3] Another (even safer) approach might be to always write to a temporary file, and rename it to $@ at the end of the recipe. <command> > $(tmp-target) mv $(tmp-target) $@ It would require a lot of Makefile changes, and result in ugly code, so I did not take it. [Note 4] A little more thoughts about a pattern rule with multiple targets (or a grouped target). %.x %.y: %.z <recipe> When interrupted, GNU Make deletes both %.x and %.y, while this solution only deletes $@. Probably, this is not a big deal. The next run of make will execute the rule again to create $@ along with the other files. [1]: https://lore.kernel.org/all/YLeot94yAaM4xbMY@gmail.com/ [2]: https://lore.kernel.org/all/20220510221333.2770571-1-robh@kernel.org/ [3]: https://lists.gnu.org/archive/html/help-make/2021-06/msg00001.html [4]: https://www.cons.org/cracauer/sigint.html Fixes: 392885ee82d3 ("kbuild: let fixdep directly write to .*.cmd files") Reported-by: Ingo Molnar <mingo@kernel.org> Reported-by: Rob Herring <robh@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> diff 88fe89a4 Thu Jan 09 22:02:24 MST 2020 Masahiro Yamada <masahiroy@kernel.org> kbuild: remove *.tmp file when filechk fails Bartosz Golaszewski reports that when "make {menu,n,g,x}config" fails due to missing packages, a temporary file is left over, which is not ignored by git. For example, if GTK+ is not installed: $ make gconfig * * Unable to find the GTK+ installation. Please make sure that * the GTK+ 2.0 development package is correctly installed. * You need gtk+-2.0 gmodule-2.0 libglade-2.0 * scripts/kconfig/Makefile:208: recipe for target 'scripts/kconfig/gconf-cfg' failed make[1]: *** [scripts/kconfig/gconf-cfg] Error 1 Makefile:567: recipe for target 'gconfig' failed make: *** [gconfig] Error 2 $ git status HEAD detached at v5.4 Untracked files: (use "git add <file>..." to include in what will be committed) scripts/kconfig/gconf-cfg.tmp nothing added to commit but untracked files present (use "git add" to track) This is because the check scripts are run with filechk, which misses to clean up the temporary file on failure. When the line { $(filechk_$(1)); } > $@.tmp; ... fails, it exits immediately due to the 'set -e'. Use trap to make sure to delete the temporary file on exit. For extra safety, I replaced $@.tmp with $(dot-target).tmp to make it a hidden file. Reported-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 2d3b1b8f Thu Nov 07 08:09:44 MST 2019 Masahiro Yamada <yamada.masahiro@socionext.com> kbuild: drop $(wildcard $^) check in if_changed* for faster rebuild The incremental build of Linux kernel is pretty slow when lots of objects are compiled. The rebuild of allmodconfig may take a few minutes even when none of the objects needs to be rebuilt. The time-consuming part in the incremental build is the evaluation of if_changed* macros since they are used in the recipes to compile C and assembly source files into objects. I notice the following code in if_changed* is expensive: $(filter-out $(PHONY) $(wildcard $^),$^) In the incremental build, every object has its .*.cmd file, which contains the auto-generated list of included headers. So, $^ are expanded into the long list of the source file + included headers, and $(wildcard $^) checks whether they exist. It may not be clear why this check exists there. Here is the record of my research. [1] The first code addition into Kbuild This code dates back to 2002. It is the pre-git era. So, I copy-pasted it from the historical git tree. | commit 4a6db0791528c220655b063cf13fefc8470dbfee (HEAD) | Author: Kai Germaschewski <kai@tp1.ruhr-uni-bochum.de> | Date: Mon Jun 17 00:22:37 2002 -0500 | | kbuild: Handle removed headers | | New and old way to handle dependencies would choke when a file | #include'd by other files was removed, since the dependency on it was | still recorded, but since it was gone, make has no idea what to do about | it (and would complain with "No rule to make <file> ...") | | We now add targets for all the previously included files, so make will | just ignore them if they disappear. | | diff --git a/Rules.make b/Rules.make | index 6ef827d3df39..7db5301ea7db 100644 | --- a/Rules.make | +++ b/Rules.make | @@ -446,7 +446,7 @@ if_changed = $(if $(strip $? \ | # execute the command and also postprocess generated .d dependencies | # file | | -if_changed_dep = $(if $(strip $? \ | +if_changed_dep = $(if $(strip $? $(filter-out FORCE $(wildcard $^),$^)\ | $(filter-out $(cmd_$(1)),$(cmd_$@))\ | $(filter-out $(cmd_$@),$(cmd_$(1)))),\ | @set -e; \ | diff --git a/scripts/fixdep.c b/scripts/fixdep.c | index b5d7bee8efc7..db45bd1888c0 100644 | --- a/scripts/fixdep.c | +++ b/scripts/fixdep.c | @@ -292,7 +292,7 @@ void parse_dep_file(void *map, size_t len) | exit(1); | } | memcpy(s, m, p-m); s[p-m] = 0; | - printf("%s: \\\n", target); | + printf("deps_%s := \\\n", target); | m = p+1; | | clear_config(); | @@ -314,7 +314,8 @@ void parse_dep_file(void *map, size_t len) | } | m = p + 1; | } | - printf("\n"); | + printf("\n%s: $(deps_%s)\n\n", target, target); | + printf("$(deps_%s):\n", target); | } | | void print_deps(void) The "No rule to make <file> ..." error can be solved by passing -MP to the compiler, but I think the detection of header removal is a good feature. When a header is removed, all source files that previously included it should be re-compiled. This makes sure we has correctly got rid of #include directives of it. This is also related with the behavior of $?. The GNU Make manual says: $? The names of all the prerequisites that are newer than the target, with spaces between them. This does not explain whether a non-existent prerequisite is considered to be newer than the target. At this point of time, GNU Make 3.7x was used, where the $? did not include non-existent prerequisites. Therefore, $(filter-out FORCE $(wildcard $^),$^) was useful to detect the header removal, and to rebuild the related objects if it is the case. [2] Change of $? behavior Later, the behavior of $? was changed (fixed) to include prerequisites that did not exist. First, GNU Make commit 64e16d6c00a5 ("Various changes getting ready for the release of 3.81.") changed it, but in the release test of 3.81, it turned out to break the kernel build. See these: - http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html - https://savannah.gnu.org/bugs/?16002 - https://savannah.gnu.org/bugs/?16051 Then, GNU Make commit 6d8d9b74d9c5 ("Numerous updates to tests for issues found on Cygwin and Windows.") reverted it for the 3.81 release to give Linux kernel time to adjust to the new behavior. After the 3.81 release, GNU Make commit 7595f38f62af ("Fixed a number of documentation bugs, plus some build/install issues:") re-added it. [3] Adjustment to the new $? behavior on Kbuild side Meanwhile, the kernel build was changed by commit 4f1933620f57 ("kbuild: change kbuild to not rely on incorrect GNU make behavior") to adjust to the new $? behavior. [4] GNU Make 3.82 released in 2010 GNU Make 3.82 was the first release that integrated the correct $? behavior. At this point, Kbuild dealt with GNU Make versions with different $? behaviors. 3.81 or older: $? does not contain any non-existent prerequisite. $(filter-out $(PHONY) $(wildcard $^),$^) was useful to detect removed include headers. 3.82 or newer: $? contains non-existent prerequisites. When a header is removed, it appears in $?. $(filter-out $(PHONY) $(wildcard $^),$^) became a redundant check. With the correct $? behavior, we could have dropped the expensive check for 3.82 or later, but we did not. (Maybe nobody noticed this optimization.) [5] The .SECONDARY special target trips up $? Some time later, I noticed $? did not work as expected under some circumstances. As above, $? should contain non-existent prerequisites, but the ones specified as SECONDARY do not appear in $?. I asked this in GNU Make ML, and it seems a bug: https://lists.gnu.org/archive/html/bug-make/2019-01/msg00001.html Since commit 8e9b61b293d9 ("kbuild: move .SECONDARY special target to Kbuild.include"), all files, including headers listed in .*.cmd files, are treated as secondary. So, we are back into the incorrect $? behavior. If we Kbuild want to react to the header removal, we need to keep $(filter-out $(PHONY) $(wildcard $^),$^) but this makes the rebuild so slow. [Summary] - I believe noticing the header removal and recompiling related objects is a nice feature for the build system. - If $? worked correctly, $(filter-out $(PHONY),$?) would be enough to detect the header removal. - Currently, $? does not work correctly when used with .SECONDARY, and Kbuild is hit by this bug. - I filed a bug report for this, but not fixed yet as of writing. - Currently, the header removal is detected by the following expensive code: $(filter-out $(PHONY) $(wildcard $^),$^) - I do not want to revert commit 8e9b61b293d9 ("kbuild: move .SECONDARY special target to Kbuild.include"). Specifying .SECONDARY globally is clean, and it matches to the Kbuild policy. This commit proactively removes the expensive check since it makes the incremental build faster. A downside is Kbuild will no longer be able to notice the header removal. You can confirm it by the full-build followed by a header removal, and then re-build. $ make defconfig all [ full build ] $ rm include/linux/device.h $ make CALL scripts/checksyscalls.sh CALL scripts/atomic/check-atomics.sh DESCEND objtool CHK include/generated/compile.h Kernel: arch/x86/boot/bzImage is ready (#11) Building modules, stage 2. MODPOST 12 modules Previously, Kbuild noticed a missing header and emits a build error. Now, Kbuild is fine with it. This is an unusual corner-case, not a big deal. Once the $? bug is fixed in GNU Make, everything will work fine. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> diff 2d3b1b8f Thu Nov 07 08:09:44 MST 2019 Masahiro Yamada <yamada.masahiro@socionext.com> kbuild: drop $(wildcard $^) check in if_changed* for faster rebuild The incremental build of Linux kernel is pretty slow when lots of objects are compiled. The rebuild of allmodconfig may take a few minutes even when none of the objects needs to be rebuilt. The time-consuming part in the incremental build is the evaluation of if_changed* macros since they are used in the recipes to compile C and assembly source files into objects. I notice the following code in if_changed* is expensive: $(filter-out $(PHONY) $(wildcard $^),$^) In the incremental build, every object has its .*.cmd file, which contains the auto-generated list of included headers. So, $^ are expanded into the long list of the source file + included headers, and $(wildcard $^) checks whether they exist. It may not be clear why this check exists there. Here is the record of my research. [1] The first code addition into Kbuild This code dates back to 2002. It is the pre-git era. So, I copy-pasted it from the historical git tree. | commit 4a6db0791528c220655b063cf13fefc8470dbfee (HEAD) | Author: Kai Germaschewski <kai@tp1.ruhr-uni-bochum.de> | Date: Mon Jun 17 00:22:37 2002 -0500 | | kbuild: Handle removed headers | | New and old way to handle dependencies would choke when a file | #include'd by other files was removed, since the dependency on it was | still recorded, but since it was gone, make has no idea what to do about | it (and would complain with "No rule to make <file> ...") | | We now add targets for all the previously included files, so make will | just ignore them if they disappear. | | diff --git a/Rules.make b/Rules.make | index 6ef827d3df39..7db5301ea7db 100644 | --- a/Rules.make | +++ b/Rules.make | @@ -446,7 +446,7 @@ if_changed = $(if $(strip $? \ | # execute the command and also postprocess generated .d dependencies | # file | | -if_changed_dep = $(if $(strip $? \ | +if_changed_dep = $(if $(strip $? $(filter-out FORCE $(wildcard $^),$^)\ | $(filter-out $(cmd_$(1)),$(cmd_$@))\ | $(filter-out $(cmd_$@),$(cmd_$(1)))),\ | @set -e; \ | diff --git a/scripts/fixdep.c b/scripts/fixdep.c | index b5d7bee8efc7..db45bd1888c0 100644 | --- a/scripts/fixdep.c | +++ b/scripts/fixdep.c | @@ -292,7 +292,7 @@ void parse_dep_file(void *map, size_t len) | exit(1); | } | memcpy(s, m, p-m); s[p-m] = 0; | - printf("%s: \\\n", target); | + printf("deps_%s := \\\n", target); | m = p+1; | | clear_config(); | @@ -314,7 +314,8 @@ void parse_dep_file(void *map, size_t len) | } | m = p + 1; | } | - printf("\n"); | + printf("\n%s: $(deps_%s)\n\n", target, target); | + printf("$(deps_%s):\n", target); | } | | void print_deps(void) The "No rule to make <file> ..." error can be solved by passing -MP to the compiler, but I think the detection of header removal is a good feature. When a header is removed, all source files that previously included it should be re-compiled. This makes sure we has correctly got rid of #include directives of it. This is also related with the behavior of $?. The GNU Make manual says: $? The names of all the prerequisites that are newer than the target, with spaces between them. This does not explain whether a non-existent prerequisite is considered to be newer than the target. At this point of time, GNU Make 3.7x was used, where the $? did not include non-existent prerequisites. Therefore, $(filter-out FORCE $(wildcard $^),$^) was useful to detect the header removal, and to rebuild the related objects if it is the case. [2] Change of $? behavior Later, the behavior of $? was changed (fixed) to include prerequisites that did not exist. First, GNU Make commit 64e16d6c00a5 ("Various changes getting ready for the release of 3.81.") changed it, but in the release test of 3.81, it turned out to break the kernel build. See these: - http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html - https://savannah.gnu.org/bugs/?16002 - https://savannah.gnu.org/bugs/?16051 Then, GNU Make commit 6d8d9b74d9c5 ("Numerous updates to tests for issues found on Cygwin and Windows.") reverted it for the 3.81 release to give Linux kernel time to adjust to the new behavior. After the 3.81 release, GNU Make commit 7595f38f62af ("Fixed a number of documentation bugs, plus some build/install issues:") re-added it. [3] Adjustment to the new $? behavior on Kbuild side Meanwhile, the kernel build was changed by commit 4f1933620f57 ("kbuild: change kbuild to not rely on incorrect GNU make behavior") to adjust to the new $? behavior. [4] GNU Make 3.82 released in 2010 GNU Make 3.82 was the first release that integrated the correct $? behavior. At this point, Kbuild dealt with GNU Make versions with different $? behaviors. 3.81 or older: $? does not contain any non-existent prerequisite. $(filter-out $(PHONY) $(wildcard $^),$^) was useful to detect removed include headers. 3.82 or newer: $? contains non-existent prerequisites. When a header is removed, it appears in $?. $(filter-out $(PHONY) $(wildcard $^),$^) became a redundant check. With the correct $? behavior, we could have dropped the expensive check for 3.82 or later, but we did not. (Maybe nobody noticed this optimization.) [5] The .SECONDARY special target trips up $? Some time later, I noticed $? did not work as expected under some circumstances. As above, $? should contain non-existent prerequisites, but the ones specified as SECONDARY do not appear in $?. I asked this in GNU Make ML, and it seems a bug: https://lists.gnu.org/archive/html/bug-make/2019-01/msg00001.html Since commit 8e9b61b293d9 ("kbuild: move .SECONDARY special target to Kbuild.include"), all files, including headers listed in .*.cmd files, are treated as secondary. So, we are back into the incorrect $? behavior. If we Kbuild want to react to the header removal, we need to keep $(filter-out $(PHONY) $(wildcard $^),$^) but this makes the rebuild so slow. [Summary] - I believe noticing the header removal and recompiling related objects is a nice feature for the build system. - If $? worked correctly, $(filter-out $(PHONY),$?) would be enough to detect the header removal. - Currently, $? does not work correctly when used with .SECONDARY, and Kbuild is hit by this bug. - I filed a bug report for this, but not fixed yet as of writing. - Currently, the header removal is detected by the following expensive code: $(filter-out $(PHONY) $(wildcard $^),$^) - I do not want to revert commit 8e9b61b293d9 ("kbuild: move .SECONDARY special target to Kbuild.include"). Specifying .SECONDARY globally is clean, and it matches to the Kbuild policy. This commit proactively removes the expensive check since it makes the incremental build faster. A downside is Kbuild will no longer be able to notice the header removal. You can confirm it by the full-build followed by a header removal, and then re-build. $ make defconfig all [ full build ] $ rm include/linux/device.h $ make CALL scripts/checksyscalls.sh CALL scripts/atomic/check-atomics.sh DESCEND objtool CHK include/generated/compile.h Kernel: arch/x86/boot/bzImage is ready (#11) Building modules, stage 2. MODPOST 12 modules Previously, Kbuild noticed a missing header and emits a build error. Now, Kbuild is fine with it. This is an unusual corner-case, not a big deal. Once the $? bug is fixed in GNU Make, everything will work fine. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> diff 2d3b1b8f Thu Nov 07 08:09:44 MST 2019 Masahiro Yamada <yamada.masahiro@socionext.com> kbuild: drop $(wildcard $^) check in if_changed* for faster rebuild The incremental build of Linux kernel is pretty slow when lots of objects are compiled. The rebuild of allmodconfig may take a few minutes even when none of the objects needs to be rebuilt. The time-consuming part in the incremental build is the evaluation of if_changed* macros since they are used in the recipes to compile C and assembly source files into objects. I notice the following code in if_changed* is expensive: $(filter-out $(PHONY) $(wildcard $^),$^) In the incremental build, every object has its .*.cmd file, which contains the auto-generated list of included headers. So, $^ are expanded into the long list of the source file + included headers, and $(wildcard $^) checks whether they exist. It may not be clear why this check exists there. Here is the record of my research. [1] The first code addition into Kbuild This code dates back to 2002. It is the pre-git era. So, I copy-pasted it from the historical git tree. | commit 4a6db0791528c220655b063cf13fefc8470dbfee (HEAD) | Author: Kai Germaschewski <kai@tp1.ruhr-uni-bochum.de> | Date: Mon Jun 17 00:22:37 2002 -0500 | | kbuild: Handle removed headers | | New and old way to handle dependencies would choke when a file | #include'd by other files was removed, since the dependency on it was | still recorded, but since it was gone, make has no idea what to do about | it (and would complain with "No rule to make <file> ...") | | We now add targets for all the previously included files, so make will | just ignore them if they disappear. | | diff --git a/Rules.make b/Rules.make | index 6ef827d3df39..7db5301ea7db 100644 | --- a/Rules.make | +++ b/Rules.make | @@ -446,7 +446,7 @@ if_changed = $(if $(strip $? \ | # execute the command and also postprocess generated .d dependencies | # file | | -if_changed_dep = $(if $(strip $? \ | +if_changed_dep = $(if $(strip $? $(filter-out FORCE $(wildcard $^),$^)\ | $(filter-out $(cmd_$(1)),$(cmd_$@))\ | $(filter-out $(cmd_$@),$(cmd_$(1)))),\ | @set -e; \ | diff --git a/scripts/fixdep.c b/scripts/fixdep.c | index b5d7bee8efc7..db45bd1888c0 100644 | --- a/scripts/fixdep.c | +++ b/scripts/fixdep.c | @@ -292,7 +292,7 @@ void parse_dep_file(void *map, size_t len) | exit(1); | } | memcpy(s, m, p-m); s[p-m] = 0; | - printf("%s: \\\n", target); | + printf("deps_%s := \\\n", target); | m = p+1; | | clear_config(); | @@ -314,7 +314,8 @@ void parse_dep_file(void *map, size_t len) | } | m = p + 1; | } | - printf("\n"); | + printf("\n%s: $(deps_%s)\n\n", target, target); | + printf("$(deps_%s):\n", target); | } | | void print_deps(void) The "No rule to make <file> ..." error can be solved by passing -MP to the compiler, but I think the detection of header removal is a good feature. When a header is removed, all source files that previously included it should be re-compiled. This makes sure we has correctly got rid of #include directives of it. This is also related with the behavior of $?. The GNU Make manual says: $? The names of all the prerequisites that are newer than the target, with spaces between them. This does not explain whether a non-existent prerequisite is considered to be newer than the target. At this point of time, GNU Make 3.7x was used, where the $? did not include non-existent prerequisites. Therefore, $(filter-out FORCE $(wildcard $^),$^) was useful to detect the header removal, and to rebuild the related objects if it is the case. [2] Change of $? behavior Later, the behavior of $? was changed (fixed) to include prerequisites that did not exist. First, GNU Make commit 64e16d6c00a5 ("Various changes getting ready for the release of 3.81.") changed it, but in the release test of 3.81, it turned out to break the kernel build. See these: - http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html - https://savannah.gnu.org/bugs/?16002 - https://savannah.gnu.org/bugs/?16051 Then, GNU Make commit 6d8d9b74d9c5 ("Numerous updates to tests for issues found on Cygwin and Windows.") reverted it for the 3.81 release to give Linux kernel time to adjust to the new behavior. After the 3.81 release, GNU Make commit 7595f38f62af ("Fixed a number of documentation bugs, plus some build/install issues:") re-added it. [3] Adjustment to the new $? behavior on Kbuild side Meanwhile, the kernel build was changed by commit 4f1933620f57 ("kbuild: change kbuild to not rely on incorrect GNU make behavior") to adjust to the new $? behavior. [4] GNU Make 3.82 released in 2010 GNU Make 3.82 was the first release that integrated the correct $? behavior. At this point, Kbuild dealt with GNU Make versions with different $? behaviors. 3.81 or older: $? does not contain any non-existent prerequisite. $(filter-out $(PHONY) $(wildcard $^),$^) was useful to detect removed include headers. 3.82 or newer: $? contains non-existent prerequisites. When a header is removed, it appears in $?. $(filter-out $(PHONY) $(wildcard $^),$^) became a redundant check. With the correct $? behavior, we could have dropped the expensive check for 3.82 or later, but we did not. (Maybe nobody noticed this optimization.) [5] The .SECONDARY special target trips up $? Some time later, I noticed $? did not work as expected under some circumstances. As above, $? should contain non-existent prerequisites, but the ones specified as SECONDARY do not appear in $?. I asked this in GNU Make ML, and it seems a bug: https://lists.gnu.org/archive/html/bug-make/2019-01/msg00001.html Since commit 8e9b61b293d9 ("kbuild: move .SECONDARY special target to Kbuild.include"), all files, including headers listed in .*.cmd files, are treated as secondary. So, we are back into the incorrect $? behavior. If we Kbuild want to react to the header removal, we need to keep $(filter-out $(PHONY) $(wildcard $^),$^) but this makes the rebuild so slow. [Summary] - I believe noticing the header removal and recompiling related objects is a nice feature for the build system. - If $? worked correctly, $(filter-out $(PHONY),$?) would be enough to detect the header removal. - Currently, $? does not work correctly when used with .SECONDARY, and Kbuild is hit by this bug. - I filed a bug report for this, but not fixed yet as of writing. - Currently, the header removal is detected by the following expensive code: $(filter-out $(PHONY) $(wildcard $^),$^) - I do not want to revert commit 8e9b61b293d9 ("kbuild: move .SECONDARY special target to Kbuild.include"). Specifying .SECONDARY globally is clean, and it matches to the Kbuild policy. This commit proactively removes the expensive check since it makes the incremental build faster. A downside is Kbuild will no longer be able to notice the header removal. You can confirm it by the full-build followed by a header removal, and then re-build. $ make defconfig all [ full build ] $ rm include/linux/device.h $ make CALL scripts/checksyscalls.sh CALL scripts/atomic/check-atomics.sh DESCEND objtool CHK include/generated/compile.h Kernel: arch/x86/boot/bzImage is ready (#11) Building modules, stage 2. MODPOST 12 modules Previously, Kbuild noticed a missing header and emits a build error. Now, Kbuild is fine with it. This is an unusual corner-case, not a big deal. Once the $? bug is fixed in GNU Make, everything will work fine. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> diff 77b0bf55 Wed Oct 03 15:30:52 MDT 2018 Nadav Amit <namit@vmware.com> kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs Using macros in inline assembly allows us to work around bugs in GCC's inlining decisions. Compile macros.S and use it to assemble all C files. Currently only x86 will use it. Background: The inlining pass of GCC doesn't include an assembler, so it's not aware of basic properties of the generated code, such as its size in bytes, or that there are such things as discontiuous blocks of code and data due to the newfangled linker feature called 'sections' ... Instead GCC uses a lazy and fragile heuristic: it does a linear count of certain syntactic and whitespace elements in inlined assembly block source code, such as a count of new-lines and semicolons (!), as a poor substitute for "code size and complexity". Unsurprisingly this heuristic falls over and breaks its neck whith certain common types of kernel code that use inline assembly, such as the frequent practice of putting useful information into alternative sections. As a result of this fresh, 20+ years old GCC bug, GCC's inlining decisions are effectively disabled for inlined functions that make use of such asm() blocks, because GCC thinks those sections of code are "large" - when in reality they are often result in just a very low number of machine instructions. This absolute lack of inlining provess when GCC comes across such asm() blocks both increases generated kernel code size and causes performance overhead, which is particularly noticeable on paravirt kernels, which make frequent use of these inlining facilities in attempt to stay out of the way when running on baremetal hardware. Instead of fixing the compiler we use a workaround: we set an assembly macro and call it from the inlined assembly block. As a result GCC considers the inline assembly block as a single instruction. (Which it often isn't but I digress.) This uglifies and bloats the source code - for example just the refcount related changes have this impact: Makefile | 9 +++++++-- arch/x86/Makefile | 7 +++++++ arch/x86/kernel/macros.S | 7 +++++++ scripts/Kbuild.include | 4 +++- scripts/mod/Makefile | 2 ++ 5 files changed, 26 insertions(+), 3 deletions(-) Yay readability and maintainability, it's not like assembly code is hard to read and maintain ... We also hope that GCC will eventually get fixed, but we are not holding our breath for that. Yet we are optimistic, it might still happen, any decade now. [ mingo: Wrote new changelog describing the background. ] Tested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Nadav Amit <namit@vmware.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kbuild@vger.kernel.org Link: http://lkml.kernel.org/r/20181003213100.189959-3-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org> diff e08d6de4 Mon May 28 03:21:38 MDT 2018 Masahiro Yamada <yamada.masahiro@socionext.com> kbuild: remove kbuild cache The kbuild cache was introduced to remember the result of shell commands, some of which are expensive to compute, such as $(call cc-option,...). However, this turned out not so clever as I had first expected. Actually, it is problematic. For example, "$(CC) -print-file-name" is cached. If the compiler is updated, the stale search path causes build error, which is difficult to figure out. Another problem scenario is cache files could be touched while install targets are running under the root permission. We can patch them if desired, but the build infrastructure is getting uglier and uglier. Now, we are going to move compiler flag tests to the configuration phase. If this is completed, the result of compiler tests will be naturally cached in the .config file. We will not have performance issues of incremental building since this testing only happens at Kconfig time. To start this work with a cleaner code base, remove the kbuild cache first. Revert the following commits: Commit 9a234a2e3843 ("kbuild: create directory for make cache only when necessary") Commit e17c400ae194 ("kbuild: shrink .cache.mk when it exceeds 1000 lines") Commit 4e56207130ed ("kbuild: Cache a few more calls to the compiler") Commit 3298b690b21c ("kbuild: Add a cache for generated variables") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org> diff 0294e6f4 Thu Feb 22 21:56:53 MST 2018 Masahiro Yamada <yamada.masahiro@socionext.com> kbuild: simplify ld-option implementation Currently, linker options are tested by the coordination of $(CC) and $(LD) because $(LD) needs some object to link. As commit 86a9df597cdd ("kbuild: fix linker feature test macros when cross compiling with Clang") addressed, we need to make sure $(CC) and $(LD) agree the underlying architecture of the passed object. This could be a bit complex when we combine tools from different groups. For example, we can use clang for $(CC), but we still need to rely on GCC toolchain for $(LD). So, I was searching for a way of standalone testing of linker options. A trick I found is to use '-v'; this not only prints the version string, but also tests if the given option is recognized. If a given option is supported, $ aarch64-linux-gnu-ld -v --fix-cortex-a53-843419 GNU ld (Linaro_Binutils-2017.11) 2.28.2.20170706 $ echo $? 0 If unsupported, $ aarch64-linux-gnu-ld -v --fix-cortex-a53-843419 GNU ld (crosstool-NG linaro-1.13.1-4.7-2013.04-20130415 - Linaro GCC 2013.04) 2.23.1 aarch64-linux-gnu-ld: unrecognized option '--fix-cortex-a53-843419' aarch64-linux-gnu-ld: use the --help option for usage information $ echo $? 1 Gold works likewise. $ aarch64-linux-gnu-ld.gold -v --fix-cortex-a53-843419 GNU gold (Linaro_Binutils-2017.11 2.28.2.20170706) 1.14 masahiro@pug:~/ref/linux$ echo $? 0 $ aarch64-linux-gnu-ld.gold -v --fix-cortex-a53-999999 GNU gold (Linaro_Binutils-2017.11 2.28.2.20170706) 1.14 aarch64-linux-gnu-ld.gold: --fix-cortex-a53-999999: unknown option aarch64-linux-gnu-ld.gold: use the --help option for usage information $ echo $? 1 LLD too. $ ld.lld -v --gc-sections LLD 7.0.0 (http://llvm.org/git/lld.git 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) $ echo $? 0 $ ld.lld -v --fix-cortex-a53-843419 LLD 7.0.0 (http://llvm.org/git/lld.git 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) $ echo $? 0 $ ld.lld -v --fix-cortex-a53-999999 ld.lld: error: unknown argument: --fix-cortex-a53-999999 LLD 7.0.0 (http://llvm.org/git/lld.git 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) $ echo $? 1 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> diff 0294e6f4 Thu Feb 22 21:56:53 MST 2018 Masahiro Yamada <yamada.masahiro@socionext.com> kbuild: simplify ld-option implementation Currently, linker options are tested by the coordination of $(CC) and $(LD) because $(LD) needs some object to link. As commit 86a9df597cdd ("kbuild: fix linker feature test macros when cross compiling with Clang") addressed, we need to make sure $(CC) and $(LD) agree the underlying architecture of the passed object. This could be a bit complex when we combine tools from different groups. For example, we can use clang for $(CC), but we still need to rely on GCC toolchain for $(LD). So, I was searching for a way of standalone testing of linker options. A trick I found is to use '-v'; this not only prints the version string, but also tests if the given option is recognized. If a given option is supported, $ aarch64-linux-gnu-ld -v --fix-cortex-a53-843419 GNU ld (Linaro_Binutils-2017.11) 2.28.2.20170706 $ echo $? 0 If unsupported, $ aarch64-linux-gnu-ld -v --fix-cortex-a53-843419 GNU ld (crosstool-NG linaro-1.13.1-4.7-2013.04-20130415 - Linaro GCC 2013.04) 2.23.1 aarch64-linux-gnu-ld: unrecognized option '--fix-cortex-a53-843419' aarch64-linux-gnu-ld: use the --help option for usage information $ echo $? 1 Gold works likewise. $ aarch64-linux-gnu-ld.gold -v --fix-cortex-a53-843419 GNU gold (Linaro_Binutils-2017.11 2.28.2.20170706) 1.14 masahiro@pug:~/ref/linux$ echo $? 0 $ aarch64-linux-gnu-ld.gold -v --fix-cortex-a53-999999 GNU gold (Linaro_Binutils-2017.11 2.28.2.20170706) 1.14 aarch64-linux-gnu-ld.gold: --fix-cortex-a53-999999: unknown option aarch64-linux-gnu-ld.gold: use the --help option for usage information $ echo $? 1 LLD too. $ ld.lld -v --gc-sections LLD 7.0.0 (http://llvm.org/git/lld.git 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) $ echo $? 0 $ ld.lld -v --fix-cortex-a53-843419 LLD 7.0.0 (http://llvm.org/git/lld.git 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) $ echo $? 0 $ ld.lld -v --fix-cortex-a53-999999 ld.lld: error: unknown argument: --fix-cortex-a53-999999 LLD 7.0.0 (http://llvm.org/git/lld.git 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) $ echo $? 1 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> diff 0294e6f4 Thu Feb 22 21:56:53 MST 2018 Masahiro Yamada <yamada.masahiro@socionext.com> kbuild: simplify ld-option implementation Currently, linker options are tested by the coordination of $(CC) and $(LD) because $(LD) needs some object to link. As commit 86a9df597cdd ("kbuild: fix linker feature test macros when cross compiling with Clang") addressed, we need to make sure $(CC) and $(LD) agree the underlying architecture of the passed object. This could be a bit complex when we combine tools from different groups. For example, we can use clang for $(CC), but we still need to rely on GCC toolchain for $(LD). So, I was searching for a way of standalone testing of linker options. A trick I found is to use '-v'; this not only prints the version string, but also tests if the given option is recognized. If a given option is supported, $ aarch64-linux-gnu-ld -v --fix-cortex-a53-843419 GNU ld (Linaro_Binutils-2017.11) 2.28.2.20170706 $ echo $? 0 If unsupported, $ aarch64-linux-gnu-ld -v --fix-cortex-a53-843419 GNU ld (crosstool-NG linaro-1.13.1-4.7-2013.04-20130415 - Linaro GCC 2013.04) 2.23.1 aarch64-linux-gnu-ld: unrecognized option '--fix-cortex-a53-843419' aarch64-linux-gnu-ld: use the --help option for usage information $ echo $? 1 Gold works likewise. $ aarch64-linux-gnu-ld.gold -v --fix-cortex-a53-843419 GNU gold (Linaro_Binutils-2017.11 2.28.2.20170706) 1.14 masahiro@pug:~/ref/linux$ echo $? 0 $ aarch64-linux-gnu-ld.gold -v --fix-cortex-a53-999999 GNU gold (Linaro_Binutils-2017.11 2.28.2.20170706) 1.14 aarch64-linux-gnu-ld.gold: --fix-cortex-a53-999999: unknown option aarch64-linux-gnu-ld.gold: use the --help option for usage information $ echo $? 1 LLD too. $ ld.lld -v --gc-sections LLD 7.0.0 (http://llvm.org/git/lld.git 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) $ echo $? 0 $ ld.lld -v --fix-cortex-a53-843419 LLD 7.0.0 (http://llvm.org/git/lld.git 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) $ echo $? 0 $ ld.lld -v --fix-cortex-a53-999999 ld.lld: error: unknown argument: --fix-cortex-a53-999999 LLD 7.0.0 (http://llvm.org/git/lld.git 4a0e4190e74cea19f8a8dc625ccaebdf8b5d1585) (compatible with GNU linkers) $ echo $? 1 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> |
H A D | Makefile.build | diff 3ed03f4d Tue Apr 18 15:43:47 MDT 2023 Miguel Ojeda <ojeda@kernel.org> rust: upgrade to Rust 1.68.2 This is the first upgrade to the Rust toolchain since the initial Rust merge, from 1.62.0 to 1.68.2 (i.e. the latest). # Context The kernel currently supports only a single Rust version [1] (rather than a minimum) given our usage of some "unstable" Rust features [2] which do not promise backwards compatibility. The goal is to reach a point where we can declare a minimum version for the toolchain. For instance, by waiting for some of the features to be stabilized. Therefore, the first minimum Rust version that the kernel will support is "in the future". # Upgrade policy Given we will eventually need to reach that minimum version, it would be ideal to upgrade the compiler from time to time to be as close as possible to that goal and find any issues sooner. In the extreme, we could upgrade as soon as a new Rust release is out. Of course, upgrading so often is in stark contrast to what one normally would need for GCC and LLVM, especially given the release schedule: 6 weeks for Rust vs. half a year for LLVM and a year for GCC. Having said that, there is no particular advantage to updating slowly either: kernel developers in "stable" distributions are unlikely to be able to use their distribution-provided Rust toolchain for the kernel anyway [3]. Instead, by routinely upgrading to the latest instead, kernel developers using Linux distributions that track the latest Rust release may be able to use those rather than Rust-provided ones, especially if their package manager allows to pin / hold back / downgrade the version for some days during windows where the version may not match. For instance, Arch, Fedora, Gentoo and openSUSE all provide and track the latest version of Rust as they get released every 6 weeks. Then, when the minimum version is reached, we will stop upgrading and decide how wide the window of support will be. For instance, a year of Rust versions. We will probably want to start small, and then widen it over time, just like the kernel did originally for LLVM, see commit 3519c4d6e08e ("Documentation: add minimum clang/llvm version"). # Unstable features stabilized This upgrade allows us to remove the following unstable features since they were stabilized: - `feature(explicit_generic_args_with_impl_trait)` (1.63). - `feature(core_ffi_c)` (1.64). - `feature(generic_associated_types)` (1.65). - `feature(const_ptr_offset_from)` (1.65, *). - `feature(bench_black_box)` (1.66, *). - `feature(pin_macro)` (1.68). The ones marked with `*` apply only to our old `rust` branch, not mainline yet, i.e. only for code that we may potentially upstream. With this patch applied, the only unstable feature allowed to be used outside the `kernel` crate is `new_uninit`, though other code to be upstreamed may increase the list. Please see [2] for details. # Other required changes Since 1.63, `rustdoc` triggers the `broken_intra_doc_links` lint for links pointing to exported (`#[macro_export]`) `macro_rules`. An issue was opened upstream [4], but it turns out it is intended behavior. For the moment, just add an explicit reference for each link. Later we can revisit this if `rustdoc` removes the compatibility measure. Nevertheless, this was helpful to discover a link that was pointing to the wrong place unintentionally. Since that one was actually wrong, it is fixed in a previous commit independently. Another change was the addition of `cfg(no_rc)` and `cfg(no_sync)` in upstream [5], thus remove our original changes for that. Similarly, upstream now tests that it compiles successfully with `#[cfg(not(no_global_oom_handling))]` [6], which allow us to get rid of some changes, such as an `#[allow(dead_code)]`. In addition, remove another `#[allow(dead_code)]` due to new uses within the standard library. Finally, add `try_extend_trusted` and move the code in `spec_extend.rs` since upstream moved it for the infallible version. # `alloc` upgrade and reviewing There are a large amount of changes, but the vast majority of them are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://rust-for-linux.com/rust-version-policy [1] Link: https://github.com/Rust-for-Linux/linux/issues/2 [2] Link: https://lore.kernel.org/rust-for-linux/CANiq72mT3bVDKdHgaea-6WiZazd8Mvurqmqegbe5JZxVyLR8Yg@mail.gmail.com/ [3] Link: https://github.com/rust-lang/rust/issues/106142 [4] Link: https://github.com/rust-lang/rust/pull/89891 [5] Link: https://github.com/rust-lang/rust/pull/98652 [6] Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-By: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Tested-by: Ariel Miculas <amiculas@cisco.com> Tested-by: David Gow <davidgow@google.com> Tested-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20230418214347.324156-4-ojeda@kernel.org [ Removed `feature(core_ffi_c)` from `uapi` ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> diff 3ed03f4d Tue Apr 18 15:43:47 MDT 2023 Miguel Ojeda <ojeda@kernel.org> rust: upgrade to Rust 1.68.2 This is the first upgrade to the Rust toolchain since the initial Rust merge, from 1.62.0 to 1.68.2 (i.e. the latest). # Context The kernel currently supports only a single Rust version [1] (rather than a minimum) given our usage of some "unstable" Rust features [2] which do not promise backwards compatibility. The goal is to reach a point where we can declare a minimum version for the toolchain. For instance, by waiting for some of the features to be stabilized. Therefore, the first minimum Rust version that the kernel will support is "in the future". # Upgrade policy Given we will eventually need to reach that minimum version, it would be ideal to upgrade the compiler from time to time to be as close as possible to that goal and find any issues sooner. In the extreme, we could upgrade as soon as a new Rust release is out. Of course, upgrading so often is in stark contrast to what one normally would need for GCC and LLVM, especially given the release schedule: 6 weeks for Rust vs. half a year for LLVM and a year for GCC. Having said that, there is no particular advantage to updating slowly either: kernel developers in "stable" distributions are unlikely to be able to use their distribution-provided Rust toolchain for the kernel anyway [3]. Instead, by routinely upgrading to the latest instead, kernel developers using Linux distributions that track the latest Rust release may be able to use those rather than Rust-provided ones, especially if their package manager allows to pin / hold back / downgrade the version for some days during windows where the version may not match. For instance, Arch, Fedora, Gentoo and openSUSE all provide and track the latest version of Rust as they get released every 6 weeks. Then, when the minimum version is reached, we will stop upgrading and decide how wide the window of support will be. For instance, a year of Rust versions. We will probably want to start small, and then widen it over time, just like the kernel did originally for LLVM, see commit 3519c4d6e08e ("Documentation: add minimum clang/llvm version"). # Unstable features stabilized This upgrade allows us to remove the following unstable features since they were stabilized: - `feature(explicit_generic_args_with_impl_trait)` (1.63). - `feature(core_ffi_c)` (1.64). - `feature(generic_associated_types)` (1.65). - `feature(const_ptr_offset_from)` (1.65, *). - `feature(bench_black_box)` (1.66, *). - `feature(pin_macro)` (1.68). The ones marked with `*` apply only to our old `rust` branch, not mainline yet, i.e. only for code that we may potentially upstream. With this patch applied, the only unstable feature allowed to be used outside the `kernel` crate is `new_uninit`, though other code to be upstreamed may increase the list. Please see [2] for details. # Other required changes Since 1.63, `rustdoc` triggers the `broken_intra_doc_links` lint for links pointing to exported (`#[macro_export]`) `macro_rules`. An issue was opened upstream [4], but it turns out it is intended behavior. For the moment, just add an explicit reference for each link. Later we can revisit this if `rustdoc` removes the compatibility measure. Nevertheless, this was helpful to discover a link that was pointing to the wrong place unintentionally. Since that one was actually wrong, it is fixed in a previous commit independently. Another change was the addition of `cfg(no_rc)` and `cfg(no_sync)` in upstream [5], thus remove our original changes for that. Similarly, upstream now tests that it compiles successfully with `#[cfg(not(no_global_oom_handling))]` [6], which allow us to get rid of some changes, such as an `#[allow(dead_code)]`. In addition, remove another `#[allow(dead_code)]` due to new uses within the standard library. Finally, add `try_extend_trusted` and move the code in `spec_extend.rs` since upstream moved it for the infallible version. # `alloc` upgrade and reviewing There are a large amount of changes, but the vast majority of them are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://rust-for-linux.com/rust-version-policy [1] Link: https://github.com/Rust-for-Linux/linux/issues/2 [2] Link: https://lore.kernel.org/rust-for-linux/CANiq72mT3bVDKdHgaea-6WiZazd8Mvurqmqegbe5JZxVyLR8Yg@mail.gmail.com/ [3] Link: https://github.com/rust-lang/rust/issues/106142 [4] Link: https://github.com/rust-lang/rust/pull/89891 [5] Link: https://github.com/rust-lang/rust/pull/98652 [6] Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-By: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Tested-by: Ariel Miculas <amiculas@cisco.com> Tested-by: David Gow <davidgow@google.com> Tested-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20230418214347.324156-4-ojeda@kernel.org [ Removed `feature(core_ffi_c)` from `uapi` ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> diff 3ed03f4d Tue Apr 18 15:43:47 MDT 2023 Miguel Ojeda <ojeda@kernel.org> rust: upgrade to Rust 1.68.2 This is the first upgrade to the Rust toolchain since the initial Rust merge, from 1.62.0 to 1.68.2 (i.e. the latest). # Context The kernel currently supports only a single Rust version [1] (rather than a minimum) given our usage of some "unstable" Rust features [2] which do not promise backwards compatibility. The goal is to reach a point where we can declare a minimum version for the toolchain. For instance, by waiting for some of the features to be stabilized. Therefore, the first minimum Rust version that the kernel will support is "in the future". # Upgrade policy Given we will eventually need to reach that minimum version, it would be ideal to upgrade the compiler from time to time to be as close as possible to that goal and find any issues sooner. In the extreme, we could upgrade as soon as a new Rust release is out. Of course, upgrading so often is in stark contrast to what one normally would need for GCC and LLVM, especially given the release schedule: 6 weeks for Rust vs. half a year for LLVM and a year for GCC. Having said that, there is no particular advantage to updating slowly either: kernel developers in "stable" distributions are unlikely to be able to use their distribution-provided Rust toolchain for the kernel anyway [3]. Instead, by routinely upgrading to the latest instead, kernel developers using Linux distributions that track the latest Rust release may be able to use those rather than Rust-provided ones, especially if their package manager allows to pin / hold back / downgrade the version for some days during windows where the version may not match. For instance, Arch, Fedora, Gentoo and openSUSE all provide and track the latest version of Rust as they get released every 6 weeks. Then, when the minimum version is reached, we will stop upgrading and decide how wide the window of support will be. For instance, a year of Rust versions. We will probably want to start small, and then widen it over time, just like the kernel did originally for LLVM, see commit 3519c4d6e08e ("Documentation: add minimum clang/llvm version"). # Unstable features stabilized This upgrade allows us to remove the following unstable features since they were stabilized: - `feature(explicit_generic_args_with_impl_trait)` (1.63). - `feature(core_ffi_c)` (1.64). - `feature(generic_associated_types)` (1.65). - `feature(const_ptr_offset_from)` (1.65, *). - `feature(bench_black_box)` (1.66, *). - `feature(pin_macro)` (1.68). The ones marked with `*` apply only to our old `rust` branch, not mainline yet, i.e. only for code that we may potentially upstream. With this patch applied, the only unstable feature allowed to be used outside the `kernel` crate is `new_uninit`, though other code to be upstreamed may increase the list. Please see [2] for details. # Other required changes Since 1.63, `rustdoc` triggers the `broken_intra_doc_links` lint for links pointing to exported (`#[macro_export]`) `macro_rules`. An issue was opened upstream [4], but it turns out it is intended behavior. For the moment, just add an explicit reference for each link. Later we can revisit this if `rustdoc` removes the compatibility measure. Nevertheless, this was helpful to discover a link that was pointing to the wrong place unintentionally. Since that one was actually wrong, it is fixed in a previous commit independently. Another change was the addition of `cfg(no_rc)` and `cfg(no_sync)` in upstream [5], thus remove our original changes for that. Similarly, upstream now tests that it compiles successfully with `#[cfg(not(no_global_oom_handling))]` [6], which allow us to get rid of some changes, such as an `#[allow(dead_code)]`. In addition, remove another `#[allow(dead_code)]` due to new uses within the standard library. Finally, add `try_extend_trusted` and move the code in `spec_extend.rs` since upstream moved it for the infallible version. # `alloc` upgrade and reviewing There are a large amount of changes, but the vast majority of them are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://rust-for-linux.com/rust-version-policy [1] Link: https://github.com/Rust-for-Linux/linux/issues/2 [2] Link: https://lore.kernel.org/rust-for-linux/CANiq72mT3bVDKdHgaea-6WiZazd8Mvurqmqegbe5JZxVyLR8Yg@mail.gmail.com/ [3] Link: https://github.com/rust-lang/rust/issues/106142 [4] Link: https://github.com/rust-lang/rust/pull/89891 [5] Link: https://github.com/rust-lang/rust/pull/98652 [6] Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-By: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Tested-by: Ariel Miculas <amiculas@cisco.com> Tested-by: David Gow <davidgow@google.com> Tested-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20230418214347.324156-4-ojeda@kernel.org [ Removed `feature(core_ffi_c)` from `uapi` ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> diff 90e53c5e7 Fri Apr 07 18:25:45 MDT 2023 Benno Lossin <benno.lossin@proton.me> rust: add pin-init API core This API is used to facilitate safe pinned initialization of structs. It replaces cumbersome `unsafe` manual initialization with elegant safe macro invocations. Due to the size of this change it has been split into six commits: 1. This commit introducing the basic public interface: traits and functions to represent and create initializers. 2. Adds the `#[pin_data]`, `pin_init!`, `try_pin_init!`, `init!` and `try_init!` macros along with their internal types. 3. Adds the `InPlaceInit` trait that allows using an initializer to create an object inside of a `Box<T>` and other smart pointers. 4. Adds the `PinnedDrop` trait and adds macro support for it in the `#[pin_data]` macro. 5. Adds the `stack_pin_init!` macro allowing to pin-initialize a struct on the stack. 6. Adds the `Zeroable` trait and `init::zeroed` function to initialize types that have `0x00` in all bytes as a valid bit pattern. -- In this section the problem that the new pin-init API solves is outlined. This message describes the entirety of the API, not just the parts introduced in this commit. For a more granular explanation and additional information on pinning and this issue, view [1]. Pinning is Rust's way of enforcing the address stability of a value. When a value gets pinned it will be impossible for safe code to move it to another location. This is done by wrapping pointers to said object with `Pin<P>`. This wrapper prevents safe code from creating mutable references to the object, preventing mutable access, which is needed to move the value. `Pin<P>` provides `unsafe` functions to circumvent this and allow modifications regardless. It is then the programmer's responsibility to uphold the pinning guarantee. Many kernel data structures require a stable address, because there are foreign pointers to them which would get invalidated by moving the structure. Since these data structures are usually embedded in structs to use them, this pinning property propagates to the container struct. Resulting in most structs in both Rust and C code needing to be pinned. So if we want to have a `mutex` field in a Rust struct, this struct also needs to be pinned, because a `mutex` contains a `list_head`. Additionally initializing a `list_head` requires already having the final memory location available, because it is initialized by pointing it to itself. But this presents another challenge in Rust: values have to be initialized at all times. There is the `MaybeUninit<T>` wrapper type, which allows handling uninitialized memory, but this requires using the `unsafe` raw pointers and a casting the type to the initialized variant. This problem gets exacerbated when considering encapsulation and the normal safety requirements of Rust code. The fields of the Rust `Mutex<T>` should not be accessible to normal driver code. After all if anyone can modify the fields, there is no way to ensure the invariants of the `Mutex<T>` are upheld. But if the fields are inaccessible, then initialization of a `Mutex<T>` needs to be somehow achieved via a function or a macro. Because the `Mutex<T>` must be pinned in memory, the function cannot return it by value. It also cannot allocate a `Box` to put the `Mutex<T>` into, because that is an unnecessary allocation and indirection which would hurt performance. The solution in the rust tree (e.g. this commit: [2]) that is replaced by this API is to split this function into two parts: 1. A `new` function that returns a partially initialized `Mutex<T>`, 2. An `init` function that requires the `Mutex<T>` to be pinned and that fully initializes the `Mutex<T>`. Both of these functions have to be marked `unsafe`, since a call to `new` needs to be accompanied with a call to `init`, otherwise using the `Mutex<T>` could result in UB. And because calling `init` twice also is not safe. While `Mutex<T>` initialization cannot fail, other structs might also have to allocate memory, which would result in conditional successful initialization requiring even more manual accommodation work. Combine this with the problem of pin-projections -- the way of accessing fields of a pinned struct -- which also have an `unsafe` API, pinned initialization is riddled with `unsafe` resulting in very poor ergonomics. Not only that, but also having to call two functions possibly multiple lines apart makes it very easy to forget it outright or during refactoring. Here is an example of the current way of initializing a struct with two synchronization primitives (see [3] for the full example): struct SharedState { state_changed: CondVar, inner: Mutex<SharedStateInner>, } impl SharedState { fn try_new() -> Result<Arc<Self>> { let mut state = Pin::from(UniqueArc::try_new(Self { // SAFETY: `condvar_init!` is called below. state_changed: unsafe { CondVar::new() }, // SAFETY: `mutex_init!` is called below. inner: unsafe { Mutex::new(SharedStateInner { token_count: 0 }) }, })?); // SAFETY: `state_changed` is pinned when `state` is. let pinned = unsafe { state.as_mut().map_unchecked_mut(|s| &mut s.state_changed) }; kernel::condvar_init!(pinned, "SharedState::state_changed"); // SAFETY: `inner` is pinned when `state` is. let pinned = unsafe { state.as_mut().map_unchecked_mut(|s| &mut s.inner) }; kernel::mutex_init!(pinned, "SharedState::inner"); Ok(state.into()) } } The pin-init API of this patch solves this issue by providing a comprehensive solution comprised of macros and traits. Here is the example from above using the pin-init API: #[pin_data] struct SharedState { #[pin] state_changed: CondVar, #[pin] inner: Mutex<SharedStateInner>, } impl SharedState { fn new() -> impl PinInit<Self> { pin_init!(Self { state_changed <- new_condvar!("SharedState::state_changed"), inner <- new_mutex!( SharedStateInner { token_count: 0 }, "SharedState::inner", ), }) } } Notably the way the macro is used here requires no `unsafe` and thus comes with the usual Rust promise of safe code not introducing any memory violations. Additionally it is now up to the caller of `new()` to decide the memory location of the `SharedState`. They can choose at the moment `Arc<T>`, `Box<T>` or the stack. -- The API has the following architecture: 1. Initializer traits `PinInit<T, E>` and `Init<T, E>` that act like closures. 2. Macros to create these initializer traits safely. 3. Functions to allow manually writing initializers. The initializers (an `impl PinInit<T, E>`) receive a raw pointer pointing to uninitialized memory and their job is to fully initialize a `T` at that location. If initialization fails, they return an error (`E`) by value. This way of initializing cannot be safely exposed to the user, since it relies upon these properties outside of the control of the trait: - the memory location (slot) needs to be valid memory, - if initialization fails, the slot should not be read from, - the value in the slot should be pinned, so it cannot move and the memory cannot be deallocated until the value is dropped. This is why using an initializer is facilitated by another trait that ensures these requirements. These initializers can be created manually by just supplying a closure that fulfills the same safety requirements as `PinInit<T, E>`. But this is an `unsafe` operation. To allow safe initializer creation, the `pin_init!` is provided along with three other variants: `try_pin_init!`, `try_init!` and `init!`. These take a modified struct initializer as a parameter and generate a closure that initializes the fields in sequence. The macros take great care in upholding the safety requirements: - A shadowed struct type is used as the return type of the closure instead of `()`. This is to prevent early returns, as these would prevent full initialization. - To ensure every field is only initialized once, a normal struct initializer is placed in unreachable code. The type checker will emit errors if a field is missing or specified multiple times. - When initializing a field fails, the whole initializer will fail and automatically drop fields that have been initialized earlier. - Only the correct initializer type is allowed for unpinned fields. You cannot use a `impl PinInit<T, E>` to initialize a structurally not pinned field. To ensure the last point, an additional macro `#[pin_data]` is needed. This macro annotates the struct itself and the user specifies structurally pinned and not pinned fields. Because dropping a pinned struct is also not allowed to break the pinning invariants, another macro attribute `#[pinned_drop]` is needed. This macro is introduced in a following commit. These two macros also have mechanisms to ensure the overall safety of the API. Additionally, they utilize a combined proc-macro, declarative macro design: first a proc-macro enables the outer attribute syntax `#[...]` and does some important pre-parsing. Notably this prepares the generics such that the declarative macro can handle them using token trees. Then the actual parsing of the structure and the emission of code is handled by a declarative macro. For pin-projections the crates `pin-project` [4] and `pin-project-lite` [5] had been considered, but were ultimately rejected: - `pin-project` depends on `syn` [6] which is a very big dependency, around 50k lines of code. - `pin-project-lite` is a more reasonable 5k lines of code, but contains a very complex declarative macro to parse generics. On top of that it would require modification that would need to be maintained independently. Link: https://rust-for-linux.com/the-safe-pinned-initialization-problem [1] Link: https://github.com/Rust-for-Linux/linux/tree/0a04dc4ddd671efb87eef54dde0fb38e9074f4be [2] Link: https://github.com/Rust-for-Linux/linux/blob/f509ede33fc10a07eba3da14aa00302bd4b5dddd/samples/rust/rust_miscdev.rs [3] Link: https://crates.io/crates/pin-project [4] Link: https://crates.io/crates/pin-project-lite [5] Link: https://crates.io/crates/syn [6] Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Wedson Almeida Filho <wedsonaf@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-7-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org> diff 90e53c5e7 Fri Apr 07 18:25:45 MDT 2023 Benno Lossin <benno.lossin@proton.me> rust: add pin-init API core This API is used to facilitate safe pinned initialization of structs. It replaces cumbersome `unsafe` manual initialization with elegant safe macro invocations. Due to the size of this change it has been split into six commits: 1. This commit introducing the basic public interface: traits and functions to represent and create initializers. 2. Adds the `#[pin_data]`, `pin_init!`, `try_pin_init!`, `init!` and `try_init!` macros along with their internal types. 3. Adds the `InPlaceInit` trait that allows using an initializer to create an object inside of a `Box<T>` and other smart pointers. 4. Adds the `PinnedDrop` trait and adds macro support for it in the `#[pin_data]` macro. 5. Adds the `stack_pin_init!` macro allowing to pin-initialize a struct on the stack. 6. Adds the `Zeroable` trait and `init::zeroed` function to initialize types that have `0x00` in all bytes as a valid bit pattern. -- In this section the problem that the new pin-init API solves is outlined. This message describes the entirety of the API, not just the parts introduced in this commit. For a more granular explanation and additional information on pinning and this issue, view [1]. Pinning is Rust's way of enforcing the address stability of a value. When a value gets pinned it will be impossible for safe code to move it to another location. This is done by wrapping pointers to said object with `Pin<P>`. This wrapper prevents safe code from creating mutable references to the object, preventing mutable access, which is needed to move the value. `Pin<P>` provides `unsafe` functions to circumvent this and allow modifications regardless. It is then the programmer's responsibility to uphold the pinning guarantee. Many kernel data structures require a stable address, because there are foreign pointers to them which would get invalidated by moving the structure. Since these data structures are usually embedded in structs to use them, this pinning property propagates to the container struct. Resulting in most structs in both Rust and C code needing to be pinned. So if we want to have a `mutex` field in a Rust struct, this struct also needs to be pinned, because a `mutex` contains a `list_head`. Additionally initializing a `list_head` requires already having the final memory location available, because it is initialized by pointing it to itself. But this presents another challenge in Rust: values have to be initialized at all times. There is the `MaybeUninit<T>` wrapper type, which allows handling uninitialized memory, but this requires using the `unsafe` raw pointers and a casting the type to the initialized variant. This problem gets exacerbated when considering encapsulation and the normal safety requirements of Rust code. The fields of the Rust `Mutex<T>` should not be accessible to normal driver code. After all if anyone can modify the fields, there is no way to ensure the invariants of the `Mutex<T>` are upheld. But if the fields are inaccessible, then initialization of a `Mutex<T>` needs to be somehow achieved via a function or a macro. Because the `Mutex<T>` must be pinned in memory, the function cannot return it by value. It also cannot allocate a `Box` to put the `Mutex<T>` into, because that is an unnecessary allocation and indirection which would hurt performance. The solution in the rust tree (e.g. this commit: [2]) that is replaced by this API is to split this function into two parts: 1. A `new` function that returns a partially initialized `Mutex<T>`, 2. An `init` function that requires the `Mutex<T>` to be pinned and that fully initializes the `Mutex<T>`. Both of these functions have to be marked `unsafe`, since a call to `new` needs to be accompanied with a call to `init`, otherwise using the `Mutex<T>` could result in UB. And because calling `init` twice also is not safe. While `Mutex<T>` initialization cannot fail, other structs might also have to allocate memory, which would result in conditional successful initialization requiring even more manual accommodation work. Combine this with the problem of pin-projections -- the way of accessing fields of a pinned struct -- which also have an `unsafe` API, pinned initialization is riddled with `unsafe` resulting in very poor ergonomics. Not only that, but also having to call two functions possibly multiple lines apart makes it very easy to forget it outright or during refactoring. Here is an example of the current way of initializing a struct with two synchronization primitives (see [3] for the full example): struct SharedState { state_changed: CondVar, inner: Mutex<SharedStateInner>, } impl SharedState { fn try_new() -> Result<Arc<Self>> { let mut state = Pin::from(UniqueArc::try_new(Self { // SAFETY: `condvar_init!` is called below. state_changed: unsafe { CondVar::new() }, // SAFETY: `mutex_init!` is called below. inner: unsafe { Mutex::new(SharedStateInner { token_count: 0 }) }, })?); // SAFETY: `state_changed` is pinned when `state` is. let pinned = unsafe { state.as_mut().map_unchecked_mut(|s| &mut s.state_changed) }; kernel::condvar_init!(pinned, "SharedState::state_changed"); // SAFETY: `inner` is pinned when `state` is. let pinned = unsafe { state.as_mut().map_unchecked_mut(|s| &mut s.inner) }; kernel::mutex_init!(pinned, "SharedState::inner"); Ok(state.into()) } } The pin-init API of this patch solves this issue by providing a comprehensive solution comprised of macros and traits. Here is the example from above using the pin-init API: #[pin_data] struct SharedState { #[pin] state_changed: CondVar, #[pin] inner: Mutex<SharedStateInner>, } impl SharedState { fn new() -> impl PinInit<Self> { pin_init!(Self { state_changed <- new_condvar!("SharedState::state_changed"), inner <- new_mutex!( SharedStateInner { token_count: 0 }, "SharedState::inner", ), }) } } Notably the way the macro is used here requires no `unsafe` and thus comes with the usual Rust promise of safe code not introducing any memory violations. Additionally it is now up to the caller of `new()` to decide the memory location of the `SharedState`. They can choose at the moment `Arc<T>`, `Box<T>` or the stack. -- The API has the following architecture: 1. Initializer traits `PinInit<T, E>` and `Init<T, E>` that act like closures. 2. Macros to create these initializer traits safely. 3. Functions to allow manually writing initializers. The initializers (an `impl PinInit<T, E>`) receive a raw pointer pointing to uninitialized memory and their job is to fully initialize a `T` at that location. If initialization fails, they return an error (`E`) by value. This way of initializing cannot be safely exposed to the user, since it relies upon these properties outside of the control of the trait: - the memory location (slot) needs to be valid memory, - if initialization fails, the slot should not be read from, - the value in the slot should be pinned, so it cannot move and the memory cannot be deallocated until the value is dropped. This is why using an initializer is facilitated by another trait that ensures these requirements. These initializers can be created manually by just supplying a closure that fulfills the same safety requirements as `PinInit<T, E>`. But this is an `unsafe` operation. To allow safe initializer creation, the `pin_init!` is provided along with three other variants: `try_pin_init!`, `try_init!` and `init!`. These take a modified struct initializer as a parameter and generate a closure that initializes the fields in sequence. The macros take great care in upholding the safety requirements: - A shadowed struct type is used as the return type of the closure instead of `()`. This is to prevent early returns, as these would prevent full initialization. - To ensure every field is only initialized once, a normal struct initializer is placed in unreachable code. The type checker will emit errors if a field is missing or specified multiple times. - When initializing a field fails, the whole initializer will fail and automatically drop fields that have been initialized earlier. - Only the correct initializer type is allowed for unpinned fields. You cannot use a `impl PinInit<T, E>` to initialize a structurally not pinned field. To ensure the last point, an additional macro `#[pin_data]` is needed. This macro annotates the struct itself and the user specifies structurally pinned and not pinned fields. Because dropping a pinned struct is also not allowed to break the pinning invariants, another macro attribute `#[pinned_drop]` is needed. This macro is introduced in a following commit. These two macros also have mechanisms to ensure the overall safety of the API. Additionally, they utilize a combined proc-macro, declarative macro design: first a proc-macro enables the outer attribute syntax `#[...]` and does some important pre-parsing. Notably this prepares the generics such that the declarative macro can handle them using token trees. Then the actual parsing of the structure and the emission of code is handled by a declarative macro. For pin-projections the crates `pin-project` [4] and `pin-project-lite` [5] had been considered, but were ultimately rejected: - `pin-project` depends on `syn` [6] which is a very big dependency, around 50k lines of code. - `pin-project-lite` is a more reasonable 5k lines of code, but contains a very complex declarative macro to parse generics. On top of that it would require modification that would need to be maintained independently. Link: https://rust-for-linux.com/the-safe-pinned-initialization-problem [1] Link: https://github.com/Rust-for-Linux/linux/tree/0a04dc4ddd671efb87eef54dde0fb38e9074f4be [2] Link: https://github.com/Rust-for-Linux/linux/blob/f509ede33fc10a07eba3da14aa00302bd4b5dddd/samples/rust/rust_miscdev.rs [3] Link: https://crates.io/crates/pin-project [4] Link: https://crates.io/crates/pin-project-lite [5] Link: https://crates.io/crates/syn [6] Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Wedson Almeida Filho <wedsonaf@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-7-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org> diff 90e53c5e7 Fri Apr 07 18:25:45 MDT 2023 Benno Lossin <benno.lossin@proton.me> rust: add pin-init API core This API is used to facilitate safe pinned initialization of structs. It replaces cumbersome `unsafe` manual initialization with elegant safe macro invocations. Due to the size of this change it has been split into six commits: 1. This commit introducing the basic public interface: traits and functions to represent and create initializers. 2. Adds the `#[pin_data]`, `pin_init!`, `try_pin_init!`, `init!` and `try_init!` macros along with their internal types. 3. Adds the `InPlaceInit` trait that allows using an initializer to create an object inside of a `Box<T>` and other smart pointers. 4. Adds the `PinnedDrop` trait and adds macro support for it in the `#[pin_data]` macro. 5. Adds the `stack_pin_init!` macro allowing to pin-initialize a struct on the stack. 6. Adds the `Zeroable` trait and `init::zeroed` function to initialize types that have `0x00` in all bytes as a valid bit pattern. -- In this section the problem that the new pin-init API solves is outlined. This message describes the entirety of the API, not just the parts introduced in this commit. For a more granular explanation and additional information on pinning and this issue, view [1]. Pinning is Rust's way of enforcing the address stability of a value. When a value gets pinned it will be impossible for safe code to move it to another location. This is done by wrapping pointers to said object with `Pin<P>`. This wrapper prevents safe code from creating mutable references to the object, preventing mutable access, which is needed to move the value. `Pin<P>` provides `unsafe` functions to circumvent this and allow modifications regardless. It is then the programmer's responsibility to uphold the pinning guarantee. Many kernel data structures require a stable address, because there are foreign pointers to them which would get invalidated by moving the structure. Since these data structures are usually embedded in structs to use them, this pinning property propagates to the container struct. Resulting in most structs in both Rust and C code needing to be pinned. So if we want to have a `mutex` field in a Rust struct, this struct also needs to be pinned, because a `mutex` contains a `list_head`. Additionally initializing a `list_head` requires already having the final memory location available, because it is initialized by pointing it to itself. But this presents another challenge in Rust: values have to be initialized at all times. There is the `MaybeUninit<T>` wrapper type, which allows handling uninitialized memory, but this requires using the `unsafe` raw pointers and a casting the type to the initialized variant. This problem gets exacerbated when considering encapsulation and the normal safety requirements of Rust code. The fields of the Rust `Mutex<T>` should not be accessible to normal driver code. After all if anyone can modify the fields, there is no way to ensure the invariants of the `Mutex<T>` are upheld. But if the fields are inaccessible, then initialization of a `Mutex<T>` needs to be somehow achieved via a function or a macro. Because the `Mutex<T>` must be pinned in memory, the function cannot return it by value. It also cannot allocate a `Box` to put the `Mutex<T>` into, because that is an unnecessary allocation and indirection which would hurt performance. The solution in the rust tree (e.g. this commit: [2]) that is replaced by this API is to split this function into two parts: 1. A `new` function that returns a partially initialized `Mutex<T>`, 2. An `init` function that requires the `Mutex<T>` to be pinned and that fully initializes the `Mutex<T>`. Both of these functions have to be marked `unsafe`, since a call to `new` needs to be accompanied with a call to `init`, otherwise using the `Mutex<T>` could result in UB. And because calling `init` twice also is not safe. While `Mutex<T>` initialization cannot fail, other structs might also have to allocate memory, which would result in conditional successful initialization requiring even more manual accommodation work. Combine this with the problem of pin-projections -- the way of accessing fields of a pinned struct -- which also have an `unsafe` API, pinned initialization is riddled with `unsafe` resulting in very poor ergonomics. Not only that, but also having to call two functions possibly multiple lines apart makes it very easy to forget it outright or during refactoring. Here is an example of the current way of initializing a struct with two synchronization primitives (see [3] for the full example): struct SharedState { state_changed: CondVar, inner: Mutex<SharedStateInner>, } impl SharedState { fn try_new() -> Result<Arc<Self>> { let mut state = Pin::from(UniqueArc::try_new(Self { // SAFETY: `condvar_init!` is called below. state_changed: unsafe { CondVar::new() }, // SAFETY: `mutex_init!` is called below. inner: unsafe { Mutex::new(SharedStateInner { token_count: 0 }) }, })?); // SAFETY: `state_changed` is pinned when `state` is. let pinned = unsafe { state.as_mut().map_unchecked_mut(|s| &mut s.state_changed) }; kernel::condvar_init!(pinned, "SharedState::state_changed"); // SAFETY: `inner` is pinned when `state` is. let pinned = unsafe { state.as_mut().map_unchecked_mut(|s| &mut s.inner) }; kernel::mutex_init!(pinned, "SharedState::inner"); Ok(state.into()) } } The pin-init API of this patch solves this issue by providing a comprehensive solution comprised of macros and traits. Here is the example from above using the pin-init API: #[pin_data] struct SharedState { #[pin] state_changed: CondVar, #[pin] inner: Mutex<SharedStateInner>, } impl SharedState { fn new() -> impl PinInit<Self> { pin_init!(Self { state_changed <- new_condvar!("SharedState::state_changed"), inner <- new_mutex!( SharedStateInner { token_count: 0 }, "SharedState::inner", ), }) } } Notably the way the macro is used here requires no `unsafe` and thus comes with the usual Rust promise of safe code not introducing any memory violations. Additionally it is now up to the caller of `new()` to decide the memory location of the `SharedState`. They can choose at the moment `Arc<T>`, `Box<T>` or the stack. -- The API has the following architecture: 1. Initializer traits `PinInit<T, E>` and `Init<T, E>` that act like closures. 2. Macros to create these initializer traits safely. 3. Functions to allow manually writing initializers. The initializers (an `impl PinInit<T, E>`) receive a raw pointer pointing to uninitialized memory and their job is to fully initialize a `T` at that location. If initialization fails, they return an error (`E`) by value. This way of initializing cannot be safely exposed to the user, since it relies upon these properties outside of the control of the trait: - the memory location (slot) needs to be valid memory, - if initialization fails, the slot should not be read from, - the value in the slot should be pinned, so it cannot move and the memory cannot be deallocated until the value is dropped. This is why using an initializer is facilitated by another trait that ensures these requirements. These initializers can be created manually by just supplying a closure that fulfills the same safety requirements as `PinInit<T, E>`. But this is an `unsafe` operation. To allow safe initializer creation, the `pin_init!` is provided along with three other variants: `try_pin_init!`, `try_init!` and `init!`. These take a modified struct initializer as a parameter and generate a closure that initializes the fields in sequence. The macros take great care in upholding the safety requirements: - A shadowed struct type is used as the return type of the closure instead of `()`. This is to prevent early returns, as these would prevent full initialization. - To ensure every field is only initialized once, a normal struct initializer is placed in unreachable code. The type checker will emit errors if a field is missing or specified multiple times. - When initializing a field fails, the whole initializer will fail and automatically drop fields that have been initialized earlier. - Only the correct initializer type is allowed for unpinned fields. You cannot use a `impl PinInit<T, E>` to initialize a structurally not pinned field. To ensure the last point, an additional macro `#[pin_data]` is needed. This macro annotates the struct itself and the user specifies structurally pinned and not pinned fields. Because dropping a pinned struct is also not allowed to break the pinning invariants, another macro attribute `#[pinned_drop]` is needed. This macro is introduced in a following commit. These two macros also have mechanisms to ensure the overall safety of the API. Additionally, they utilize a combined proc-macro, declarative macro design: first a proc-macro enables the outer attribute syntax `#[...]` and does some important pre-parsing. Notably this prepares the generics such that the declarative macro can handle them using token trees. Then the actual parsing of the structure and the emission of code is handled by a declarative macro. For pin-projections the crates `pin-project` [4] and `pin-project-lite` [5] had been considered, but were ultimately rejected: - `pin-project` depends on `syn` [6] which is a very big dependency, around 50k lines of code. - `pin-project-lite` is a more reasonable 5k lines of code, but contains a very complex declarative macro to parse generics. On top of that it would require modification that would need to be maintained independently. Link: https://rust-for-linux.com/the-safe-pinned-initialization-problem [1] Link: https://github.com/Rust-for-Linux/linux/tree/0a04dc4ddd671efb87eef54dde0fb38e9074f4be [2] Link: https://github.com/Rust-for-Linux/linux/blob/f509ede33fc10a07eba3da14aa00302bd4b5dddd/samples/rust/rust_miscdev.rs [3] Link: https://crates.io/crates/pin-project [4] Link: https://crates.io/crates/pin-project-lite [5] Link: https://crates.io/crates/syn [6] Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Wedson Almeida Filho <wedsonaf@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-7-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org> diff 295d8398 Sat Jan 07 02:18:15 MST 2023 Masahiro Yamada <masahiroy@kernel.org> kbuild: specify output names separately for each emission type from rustc In Kbuild, two different rules must not write to the same file, but it happens when compiling rust source files. For example, set CONFIG_SAMPLE_RUST_MINIMAL=m and run the following: $ make -j$(nproc) samples/rust/rust_minimal.o samples/rust/rust_minimal.rsi \ samples/rust/rust_minimal.s samples/rust/rust_minimal.ll [snip] RUSTC [M] samples/rust/rust_minimal.o RUSTC [M] samples/rust/rust_minimal.rsi RUSTC [M] samples/rust/rust_minimal.s RUSTC [M] samples/rust/rust_minimal.ll mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory make[3]: *** [scripts/Makefile.build:334: samples/rust/rust_minimal.ll] Error 1 make[3]: *** Waiting for unfinished jobs.... mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory make[3]: *** [scripts/Makefile.build:309: samples/rust/rust_minimal.o] Error 1 mv: cannot stat 'samples/rust/rust_minimal.d': No such file or directory make[3]: *** [scripts/Makefile.build:326: samples/rust/rust_minimal.s] Error 1 make[2]: *** [scripts/Makefile.build:504: samples/rust] Error 2 make[1]: *** [scripts/Makefile.build:504: samples] Error 2 make: *** [Makefile:2008: .] Error 2 The reason for the error is that 4 threads running in parallel renames the same file, samples/rust/rust_minimal.d. This does not happen when compiling C or assembly files because -Wp,-MMD,$(depfile) explicitly specifies the dependency filepath. $(depfile) is a unique path for each target. Currently, rustc is only given --out-dir and --emit=<list-of-types> So, all the rust build rules output the dep-info into the default <CRATE_NAME>.d, which causes the path conflict. Fortunately, the --emit option is able to specify the output path individually, with the form --emit=<type>=<path>. Add --emit=dep-info=$(depfile) to the common part. Also, remove the redundant --out-dir because the output path is specified for each type. The code gets much cleaner because we do not need to rename *.d files. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Tested-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> diff c67a85be Fri Oct 14 10:53:02 MDT 2022 Nick Desaulniers <ndesaulniers@google.com> kbuild: add -fno-discard-value-names to cmd_cc_ll_c When debugging LLVM IR, it can be handy for clang to not discard value names used for local variables and parameters. Compare the generated IR. -fdiscard-value-names: define i32 @core_sys_select(i32 %0, ptr %1, ptr %2, ptr %3, ptr %4) { %6 = alloca i64 %7 = alloca %struct.poll_wqueues %8 = alloca [64 x i32] -fno-discard-value-names: define i32 @core_sys_select(i32 %n, ptr %inp, ptr %outp, ptr %exp, ptr %end_time) { %expire.i = alloca i64 %table.i = alloca %struct.poll_wqueues %stack_fds = alloca [64 x i32] The rule for generating human readable LLVM IR (.ll) is only useful as a debugging feature: $ make LLVM=1 fs/select.ll As Fangrui notes: A LLVM_ENABLE_ASSERTIONS=off build of Clang defaults to -fdiscard-value-names. A LLVM_ENABLE_ASSERTIONS=on build of Clang defaults to -fno-discard-value-names. Explicitly enable -fno-discard-value-names so that the IR always contains value names regardless of whether assertions were enabled or not. Assertions generally are not enabled in releases of clang packaged by distributions. Link: https://github.com/ClangBuiltLinux/linux/issues/1467 Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Fangrui Song <maskray@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff c6031b1d Fri May 27 04:01:53 MDT 2022 Masahiro Yamada <masahiroy@kernel.org> kbuild: make *.mod rule robust against too long argument error Like built-in.a, the command length of the *.mod rule scales with the depth of the directory times the number of objects in the Makefile. Add $(obj)/ by the shell command (awk) instead of by Make's builtin function. In-tree modules still have some room to the limit (ARG_MAX=2097152), but this is more future-proof for big modules in a deep directory. For example, you can build i915 as a module (CONFIG_DRM_I915=m) and compare drivers/gpu/drm/i915/.i915.mod.cmd with/without this commit. The issue is more critical for external modules because the M= path can be very long as Jeff Johnson reported before [1]. [1] https://lore.kernel.org/linux-kbuild/4c02050c4e95e4cb8cc04282695f8404@codeaurora.org/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Tested-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM-14 (x86-64) diff 4ab7674f Mon Apr 18 10:50:39 MDT 2022 Josh Poimboeuf <jpoimboe@redhat.com> objtool: Make jump label hack optional Objtool secretly does a jump label hack to overcome the limitations of the toolchain. Make the hack explicit (and optional for other arches) by turning it into a cmdline option and kernel config option. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Link: https://lkml.kernel.org/r/3bdcbfdd27ecb01ddec13c04bdf756a583b13d24.1650300597.git.jpoimboe@redhat.com |
/linux-master/arch/arm/boot/ | ||
H A D | Makefile | diff 4f193362 Sun Mar 05 15:14:10 MST 2006 Paul Smith <psmith@gnu.org> kbuild: change kbuild to not rely on incorrect GNU make behavior The kbuild system takes advantage of an incorrect behavior in GNU make. Once this behavior is fixed, all files in the kernel rebuild every time, even if nothing has changed. This patch ensures kbuild works with both the incorrect and correct behaviors of GNU make. For more details on the incorrect behavior, see: http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html Changes in this patch: - Keep all targets that are to be marked .PHONY in a variable, PHONY. - Add .PHONY: $(PHONY) to mark them properly. - Remove any $(PHONY) files from the $? list when determining whether targets are up-to-date or not. Signed-off-by: Paul Smith <psmith@gnu.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> diff 4f193362 Sun Mar 05 15:14:10 MST 2006 Paul Smith <psmith@gnu.org> kbuild: change kbuild to not rely on incorrect GNU make behavior The kbuild system takes advantage of an incorrect behavior in GNU make. Once this behavior is fixed, all files in the kernel rebuild every time, even if nothing has changed. This patch ensures kbuild works with both the incorrect and correct behaviors of GNU make. For more details on the incorrect behavior, see: http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html Changes in this patch: - Keep all targets that are to be marked .PHONY in a variable, PHONY. - Add .PHONY: $(PHONY) to mark them properly. - Remove any $(PHONY) files from the $? list when determining whether targets are up-to-date or not. Signed-off-by: Paul Smith <psmith@gnu.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> |
/linux-master/arch/sh/ | ||
H A D | Makefile | diff 4bd04b20 Sun Feb 19 07:15:55 MST 2023 Masahiro Yamada <masahiroy@kernel.org> sh: Remove compiler flag duplication Every compiler flag added by arch/sh/Makefile is passed to the compiler twice: $(KBUILD_CPPFLAGS) + $(KBUILD_CFLAGS) is used for compiling *.c $(KBUILD_CPPFLAGS) + $(KBUILD_AFLAGS) is used for compiling *.S Given the above, adding $(cflags-y) to all of KBUILD_{CPP/C/A}FLAGS ends up with duplication. Add -I options to $(KBUILD_CPPFLAGS), and the rest of $(cflags-y) to KBUILD_{C,A}FLAGS. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Link: https://lore.kernel.org/r/20230219141555.2308306-4-masahiroy@kernel.org Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> diff 4bd04b20 Sun Feb 19 07:15:55 MST 2023 Masahiro Yamada <masahiroy@kernel.org> sh: Remove compiler flag duplication Every compiler flag added by arch/sh/Makefile is passed to the compiler twice: $(KBUILD_CPPFLAGS) + $(KBUILD_CFLAGS) is used for compiling *.c $(KBUILD_CPPFLAGS) + $(KBUILD_AFLAGS) is used for compiling *.S Given the above, adding $(cflags-y) to all of KBUILD_{CPP/C/A}FLAGS ends up with duplication. Add -I options to $(KBUILD_CPPFLAGS), and the rest of $(cflags-y) to KBUILD_{C,A}FLAGS. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Link: https://lore.kernel.org/r/20230219141555.2308306-4-masahiroy@kernel.org Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> diff 8a2fd5f3 Tue Oct 28 02:19:35 MDT 2008 Paul Mundt <lethal@linux-sh.org> sh: Fix FPU tuning on toolchains with mismatched multilib targets. Presently there is very little standing in the way of using an SH-4 toolchain for building an SH-2 kernel, and vice versa. Binutils itself has no limitations whatsoever and supports explicit ISA hinting, which we already use with varying degrees of success today. This leaves GCC as the odd one out, due to a rather dubious policy decision by the GCC folks to not include all of the CPU family variants in the default list of multilib targets in GCC4. Despite best efforts to the contrary, libgcc itself already contains awareness of the various CPU types and remains generally usable, allowing it to safely be referenced even on a mismatched target (and indeed, explicit ISA tuning by binutils keeps us honest in terms of ensuring that we do not link incompatible objects in). In order to support this, a couple of changes had to be made. Firstly, the introduction of MAYBE_DECLARE_EXPORT(), which provides a __weak extern reference for libgcc resident routines when finer-grained -m<cpu-family> based tuning is not supported by the toolchain. This fixes up the __sdivsi3_i4i and __udivsi3_i4i references when dealing with SH-2 kernels linked with an SH-4 libgcc. Secondly, in case where we are unable to find a suitable match for CPU family tuning but still have a toolchain that defaults to FP instruction generation, a suitable nofpu target must be selected. This is accomplished by selecting the first nofpu multilib target supported by the toolchain, which is also necessary for selecting the proper libgcc to link against. Signed-off-by: Paul Mundt <lethal@linux-sh.org> diff 8a2fd5f3 Tue Oct 28 02:19:35 MDT 2008 Paul Mundt <lethal@linux-sh.org> sh: Fix FPU tuning on toolchains with mismatched multilib targets. Presently there is very little standing in the way of using an SH-4 toolchain for building an SH-2 kernel, and vice versa. Binutils itself has no limitations whatsoever and supports explicit ISA hinting, which we already use with varying degrees of success today. This leaves GCC as the odd one out, due to a rather dubious policy decision by the GCC folks to not include all of the CPU family variants in the default list of multilib targets in GCC4. Despite best efforts to the contrary, libgcc itself already contains awareness of the various CPU types and remains generally usable, allowing it to safely be referenced even on a mismatched target (and indeed, explicit ISA tuning by binutils keeps us honest in terms of ensuring that we do not link incompatible objects in). In order to support this, a couple of changes had to be made. Firstly, the introduction of MAYBE_DECLARE_EXPORT(), which provides a __weak extern reference for libgcc resident routines when finer-grained -m<cpu-family> based tuning is not supported by the toolchain. This fixes up the __sdivsi3_i4i and __udivsi3_i4i references when dealing with SH-2 kernels linked with an SH-4 libgcc. Secondly, in case where we are unable to find a suitable match for CPU family tuning but still have a toolchain that defaults to FP instruction generation, a suitable nofpu target must be selected. This is accomplished by selecting the first nofpu multilib target supported by the toolchain, which is also necessary for selecting the proper libgcc to link against. Signed-off-by: Paul Mundt <lethal@linux-sh.org> diff 4385e12b Fri Aug 01 16:14:09 MDT 2008 Paul Mundt <lethal@linux-sh.org> sh: Revert the location change of auto-generated asm/machtypes.h This ended up causing build breakage on O= builds, as reported by Adrian: <-- snip --> ... CC init/main.o In file included from /home/bunk/linux/kernel-2.6/git/linux-2.6/arch/sh/include/asm/irq.h:4, from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/irq.h:23, from /home/bunk/linux/kernel-2.6/git/linux-2.6/arch/sh/include/asm/hardirq.h:5, from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/hardirq.h:7, from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/asm-generic/local.h:5, from /home/bunk/linux/kernel-2.6/git/linux-2.6/arch/sh/include/asm/local.h:4, from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/module.h:19, from /home/bunk/linux/kernel-2.6/git/linux-2.6/init/main.c:13: /home/bunk/linux/kernel-2.6/git/linux-2.6/arch/sh/include/asm/machvec.h:15:27: error: asm/machtypes.h: No such file or directory make[2]: *** [init/main.o] Error 1 <-- snip --> So we simply move machtypes.h back to its original place. asm-offsets.h is still generated there regardless, until such a time that we find a better place to stash auto-generated files. Reported-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Paul Mundt <lethal@linux-sh.org> diff 4385e12b Fri Aug 01 16:14:09 MDT 2008 Paul Mundt <lethal@linux-sh.org> sh: Revert the location change of auto-generated asm/machtypes.h This ended up causing build breakage on O= builds, as reported by Adrian: <-- snip --> ... CC init/main.o In file included from /home/bunk/linux/kernel-2.6/git/linux-2.6/arch/sh/include/asm/irq.h:4, from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/irq.h:23, from /home/bunk/linux/kernel-2.6/git/linux-2.6/arch/sh/include/asm/hardirq.h:5, from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/hardirq.h:7, from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/asm-generic/local.h:5, from /home/bunk/linux/kernel-2.6/git/linux-2.6/arch/sh/include/asm/local.h:4, from /home/bunk/linux/kernel-2.6/git/linux-2.6/include/linux/module.h:19, from /home/bunk/linux/kernel-2.6/git/linux-2.6/init/main.c:13: /home/bunk/linux/kernel-2.6/git/linux-2.6/arch/sh/include/asm/machvec.h:15:27: error: asm/machtypes.h: No such file or directory make[2]: *** [init/main.o] Error 1 <-- snip --> So we simply move machtypes.h back to its original place. asm-offsets.h is still generated there regardless, until such a time that we find a better place to stash auto-generated files. Reported-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Paul Mundt <lethal@linux-sh.org> diff 4cec1a37 Fri Jun 06 02:04:56 MDT 2008 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com> sh: Renesas Solutions SH7763RDP board support This patch adds basic support for the SH7763RDP board. This supports a basic stuff provided in SH7763, like SCIF, NOR Flash and USB host. Signed-off-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org> diff 4c91d6b1 Sun Nov 11 01:41:56 MST 2007 Paul Mundt <lethal@linux-sh.org> sh: Fix up the head-y targets for _32 and _64. Signed-off-by: Paul Mundt <lethal@linux-sh.org> diff 4d2718d0 Mon Oct 29 18:54:12 MDT 2007 Manuel Lauss <mano@roarinelk.homelinux.net> sh: fix zImage build with >=binutils-2.18 Starting with binutils somewhere around 2.17.50.14 the vmlinux file contains a ".note.gnu.build-id" section which doesn't get removed when the zImage is built; resulting in a 2GB intermediate file and a broken zImage. Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net> Signed-off-by: Paul Mundt <lethal@linux-sh.org> diff 4aafae27 Mon Jul 16 22:52:38 MDT 2007 Kristoffer Ericson <kristoffer.ericson@gmail.com> sh: hd64461 tidying. Kill off the hd64461 io.c, as all of the hd64461 users are now using the generic I/O routines. [ hd64461/ moved to hd64461.c by Paul ] Signed-off-by: Kristoffer Ericson <kristoffer.ericson@gmail.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org> |
/linux-master/arch/um/ | ||
H A D | Makefile | diff f44f1e7d Tue May 23 18:32:31 MDT 2017 Florian Fainelli <f.fainelli@gmail.com> um: Avoid longjmp/setjmp symbol clashes with libpthread.a Building a statically linked UML kernel on a Centos 6.9 host resulted in the following linking failure (GCC 4.4, glibc-2.12): /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o): In function `siglongjmp': (.text+0x8490): multiple definition of `longjmp' arch/x86/um/built-in.o:/local/users/fainelli/openwrt/trunk/build_dir/target-x86_64_musl/linux-uml/linux-4.4.69/arch/x86/um/setjmp_64.S:44: first defined here /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o): In function `sem_open': (.text+0x77cd): warning: the use of `mktemp' is dangerous, better use `mkstemp' collect2: ld returned 1 exit status make[4]: *** [vmlinux] Error 1 Adopt a solution similar to the one done for vmap where we define longjmp/setjmp to be kernel_longjmp/setjmp. In the process, make sure we do rename the functions in arch/x86/um/setjmp_*.S accordingly. Fixes: a7df4716d195 ("um: link with -lpthread") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Richard Weinberger <richard@nod.at> diff fb1770aa Wed Nov 18 07:12:09 MST 2015 Lorenzo Colitti <lorenzo@google.com> arch: um: fix error when linking vmlinux. On gcc Ubuntu 4.8.4-2ubuntu1~14.04, linking vmlinux fails with: arch/um/os-Linux/built-in.o: In function `os_timer_create': /android/kernel/android/arch/um/os-Linux/time.c:51: undefined reference to `timer_create' arch/um/os-Linux/built-in.o: In function `os_timer_set_interval': /android/kernel/android/arch/um/os-Linux/time.c:84: undefined reference to `timer_settime' arch/um/os-Linux/built-in.o: In function `os_timer_remain': /android/kernel/android/arch/um/os-Linux/time.c:109: undefined reference to `timer_gettime' arch/um/os-Linux/built-in.o: In function `os_timer_one_shot': /android/kernel/android/arch/um/os-Linux/time.c:132: undefined reference to `timer_settime' arch/um/os-Linux/built-in.o: In function `os_timer_disable': /android/kernel/android/arch/um/os-Linux/time.c:145: undefined reference to `timer_settime' This is because -lrt appears in the generated link commandline after arch/um/os-Linux/built-in.o. Fix this by removing -lrt from arch/um/Makefile and adding it to the UM-specific section of scripts/link-vmlinux.sh. Signed-off-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Richard Weinberger <richard@nod.at> diff 4de1c5f6 Thu Aug 18 13:01:19 MDT 2011 Al Viro <viro@ftp.linux.org.uk> um: take user_constants.h to include/generated Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at> diff 4d45db9c Thu Aug 18 13:00:59 MDT 2011 Al Viro <viro@ftp.linux.org.uk> um: switch to -idirafter, get saner kern_constants.h out of that Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at> diff 51b563fc Sat Sep 19 16:28:22 MDT 2009 Sam Ravnborg <sam@ravnborg.org> arm, cris, mips, sparc, powerpc, um, xtensa: fix build with bash 4.0 Albin Tonnerre <albin.tonnerre@free-electrons.com> reported: Bash 4 filters out variables which contain a dot in them. This happends to be the case of CPPFLAGS_vmlinux.lds. This is rather unfortunate, as it now causes build failures when using SHELL=/bin/bash to compile, or when bash happens to be used by make (eg when it's /bin/sh) Remove the common definition of CPPFLAGS_vmlinux.lds by pushing relevant stuff to either Makefile.build or the arch specific kernel/Makefile where we build the linker script. This is also nice cleanup as we move the information out where it is used. Notes for the different architectures touched: arm - we use an already exported symbol cris - we use a config symbol aleady available [Not build tested] mips - the jiffies complexity has moved to vmlinux.lds.S where we need it. Added a few variables to CPPFLAGS - they are only used by the linker script. [Not build tested] powerpc - removed assignment that is not needed [not build tested] sparc - simplified it using $(BITS) um - introduced a few new exported variables to deal with this xtensa - added options to CPP invocation [not build tested] Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Chris Zankel <chris@zankel.net> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> diff 4f81c535 Mon Jul 07 11:36:56 MDT 2008 Jeff Dike <jdike@addtoit.com> [UML] fix gcc ICEs and unresolved externs There are various constraints on the use of unit-at-a-time: - i386 uses no-unit-at-a-time for pre-4.0 (not 4.3) - x86_64 uses unit-at-a-time always Uli reported a crash on x86_64 with gcc 4.1.2 with unit-at-a-time, resulting in commit c0a18111e571138747a98af18b3a2124df56a0d1 Ingo reported a gcc internal error with gcc 4.3 with no-unit-at-a-timem, resulting in 22eecde2f9034764a3fd095eecfa3adfb8ec9a98 Benny Halevy is seeing extern inlines not resolved with gcc 4.3 with no-unit-at-a-time This patch reintroduces unit-at-a-time for gcc >= 4.0, bringing back the possibility of Uli's crash. If that happens, we'll debug it. I started seeing both the internal compiler errors and unresolved inlines on Fedora 9. This patch fixes both problems, without so far reintroducing the crash reported by Uli. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Benny Halevy <bhalevy@panasas.com> Cc: Adrian Bunk <bunk@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ulrich Drepper <drepper@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> diff 4c9e1385 Tue Oct 16 02:26:54 MDT 2007 Jeff Dike <jdike@addtoit.com> uml: style fixes pass 1 Formatting changes in the files which have been changed in the tt-removal patchset so far. These include: copyright updates header file trimming style fixes adding severity to printks indenting Kconfig help according to the predominant kernel style These changes should be entirely non-functional. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> diff 4b3f686d Tue Oct 03 14:21:02 MDT 2006 Matt LaPlante <laplam@rpi.edu> Attack of "the the"s in arch The patch below corrects multiple occurances of "the the" typos across several files, both in source comments and KConfig files. There is no actual code changed, only text. Note this only affects the /arch directory, and I believe I could find many more elsewhere. :) Signed-off-by: Adrian Bunk <bunk@stusta.de> diff 4f193362 Sun Mar 05 15:14:10 MST 2006 Paul Smith <psmith@gnu.org> kbuild: change kbuild to not rely on incorrect GNU make behavior The kbuild system takes advantage of an incorrect behavior in GNU make. Once this behavior is fixed, all files in the kernel rebuild every time, even if nothing has changed. This patch ensures kbuild works with both the incorrect and correct behaviors of GNU make. For more details on the incorrect behavior, see: http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html Changes in this patch: - Keep all targets that are to be marked .PHONY in a variable, PHONY. - Add .PHONY: $(PHONY) to mark them properly. - Remove any $(PHONY) files from the $? list when determining whether targets are up-to-date or not. Signed-off-by: Paul Smith <psmith@gnu.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> diff 4f193362 Sun Mar 05 15:14:10 MST 2006 Paul Smith <psmith@gnu.org> kbuild: change kbuild to not rely on incorrect GNU make behavior The kbuild system takes advantage of an incorrect behavior in GNU make. Once this behavior is fixed, all files in the kernel rebuild every time, even if nothing has changed. This patch ensures kbuild works with both the incorrect and correct behaviors of GNU make. For more details on the incorrect behavior, see: http://lists.gnu.org/archive/html/bug-make/2006-03/msg00003.html Changes in this patch: - Keep all targets that are to be marked .PHONY in a variable, PHONY. - Add .PHONY: $(PHONY) to mark them properly. - Remove any $(PHONY) files from the $? list when determining whether targets are up-to-date or not. Signed-off-by: Paul Smith <psmith@gnu.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> |
/linux-master/scripts/kconfig/ | ||
H A D | Makefile | diff fd65465b Fri Aug 31 03:34:55 MDT 2018 Masahiro Yamada <yamada.masahiro@socionext.com> kconfig: do not require pkg-config on make {menu,n}config Meelis Roos reported a {menu,n}config regression: "I have libncurses devel package installed in the default system location (as do 99%+ on actual developers probably) and in this case, pkg-config is useless. pkg-config is needed only when libraries and headers are installed in non-default locations but it is bad to require installation of pkg-config on all the machines where make menuconfig would be possibly run." For {menu,n}config, do not use pkg-config if it is not installed. For {g,x}config, keep checking pkg-config since we really rely on it for finding the installation paths of the required packages. Fixes: 4ab3b80159d4 ("kconfig: check for pkg-config on make {menu,n,g,x}config") Reported-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Meelis Roos <mroos@linux.ee> Tested-by: Randy Dunlap <rdunlap@infradead.org> diff 4bf6a9af Tue Aug 14 18:36:49 MDT 2018 Randy Dunlap <rdunlap@infradead.org> kconfig: add build-only configurator targets Add build-only targets for build_menuconfig, build_nconfig, build_xconfig, and build_gconfig. (targets must end in "config" to qualify in top-level Makefile) This allows these target to be built without execution (e.g., to look for errors or warnings) and/or to be built and checked by sparse. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> diff 4ab3b801 Thu Jun 28 17:39:50 MDT 2018 Randy Dunlap <rdunlap@infradead.org> kconfig: check for pkg-config on make {menu,n,g,x}config Each of 'make {menu,n,g,x}config' uses (needs) pkg-config to make sure that other required files are present and to determine build flags settings, but none of these check that pkg-config itself is present. Add a check for all 4 of these targets and update Documentation/process/changes.rst to mention 'pkg-config'. Fixes kernel bugzilla #77511: https://bugzilla.kernel.org/show_bug.cgi?id=77511 Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Bjørn Forsman <bjorn.forsman@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> diff 4ab3b801 Thu Jun 28 17:39:50 MDT 2018 Randy Dunlap <rdunlap@infradead.org> kconfig: check for pkg-config on make {menu,n,g,x}config Each of 'make {menu,n,g,x}config' uses (needs) pkg-config to make sure that other required files are present and to determine build flags settings, but none of these check that pkg-config itself is present. Add a check for all 4 of these targets and update Documentation/process/changes.rst to mention 'pkg-config'. Fixes kernel bugzilla #77511: https://bugzilla.kernel.org/show_bug.cgi?id=77511 Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Bjørn Forsman <bjorn.forsman@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff 588446a8 Sun Nov 01 20:12:53 MST 2015 Thiago Macieira <thiago.macieira@intel.com> Use pkg-config to find Qt 4 and 5 instead of direct qmake The Qt Project recommendation is that there should always be a "qmake" binary and it should never be renamed. If it's necessary to handle multiple Qt versions, the Qt Project recommends using qtchooser. Unfortunately, some distros do not follow the recommendation, so we would need to check qmake-qt4, qmake-qt5, etc. So, instead, let's try pkg-config. Signed-off-by: Thiago Macieira <thiago.macieira@intel.com> Reported-by: Alexey Brodkin <abrodkin@synopsys.com> Acked-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Michal Marek <mmarek@suse.com> diff d1b0dc90 Tue Sep 22 12:36:39 MDT 2015 Thiago Macieira <thiago.macieira@intel.com> Update the buildsystem for KConfig finding Qt The buildsystem will now only search for Qt 4 and Qt 5. Support for Qt 2 and 3 was dropped in the previous commits (Qt 3 was EOL'ed in 2010 or so...). For Qt 5, to be future-proof with the future direction notice appearing in the 5.5 release, C++11 support is automatically enabled. Signed-off-by: Thiago Macieira <thiago.macieira@intel.com> Signed-off-by: Michal Marek <mmarek@suse.com> diff 48485949 Wed Jul 04 14:23:29 MDT 2012 Yaakov Selkowitz <yselkowitz@users.sourceforge.net> xconfig: use pkgconfig to find moc Various schemes exist to allow parallel installations of multiple major versions of Qt (4.x with the previous 3.x and/or the upcoming 5.x). QtCore.pc includes a moc_location variable which should be a more reliable way to find moc. Signed-off-by: Yaakov Selkowitz <yselkowitz@users.sourceforge.net> Signed-off-by: Michal Marek <mmarek@suse.cz> diff 7cf3d73b Sat Jul 31 15:35:34 MDT 2010 Sam Ravnborg <sam@ravnborg.org> kconfig: add savedefconfig savedefconfig will save a minimal config to a file named "defconfig". The config symbols are saved in the same order as they appear in the menu structure so it should be possible to map them to the relevant menus if desired. The implementation was tested against several minimal configs for arm which was created using brute-force. There was one regression related to default numbers which had their valid range further limited by another symbol. Sample: config FOO int "foo" default 4 config BAR int "bar" range 0 FOO If FOO is set to 3 then BAR cannot take a value higher than 3. But the current implementation will set BAR equal to 4. This is seldomly used and the final configuration is OK, and the fix was non-trivial. So it was documented in the code and left as is. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Michal Marek <mmarek@suse.cz> diff 7cf3d73b Sat Jul 31 15:35:34 MDT 2010 Sam Ravnborg <sam@ravnborg.org> kconfig: add savedefconfig savedefconfig will save a minimal config to a file named "defconfig". The config symbols are saved in the same order as they appear in the menu structure so it should be possible to map them to the relevant menus if desired. The implementation was tested against several minimal configs for arm which was created using brute-force. There was one regression related to default numbers which had their valid range further limited by another symbol. Sample: config FOO int "foo" default 4 config BAR int "bar" range 0 FOO If FOO is set to 3 then BAR cannot take a value higher than 3. But the current implementation will set BAR equal to 4. This is seldomly used and the final configuration is OK, and the fix was non-trivial. So it was documented in the code and left as is. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Michal Marek <mmarek@suse.cz> |
/linux-master/arch/powerpc/ | ||
H A D | Makefile | diff 402928b5 Wed Dec 06 04:55:48 MST 2023 Michael Ellerman <mpe@ellerman.id.au> powerpc/Makefile: Auto detect cross compiler If no cross compiler is specified, try to auto detect one. Look for various combinations, matching: powerpc(64(le)?)?(-unknown)?-linux(-gnu)?- There are more possibilities, but the above is known to find a compiler on Fedora and Ubuntu (which use linux-gnu-), and also detects the kernel.org cross compilers (which use linux-). This allows cross compiling with simply: # Ubuntu $ sudo apt install gcc-powerpc-linux-gnu # Fedora $ sudo dnf install gcc-powerpc64-linux-gnu $ make ARCH=powerpc defconfig $ make ARCH=powerpc -j 4 Inspired by arch/parisc/Makefile. Acked-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231206115548.1466874-4-mpe@ellerman.id.au diff 402928b5 Wed Dec 06 04:55:48 MST 2023 Michael Ellerman <mpe@ellerman.id.au> powerpc/Makefile: Auto detect cross compiler If no cross compiler is specified, try to auto detect one. Look for various combinations, matching: powerpc(64(le)?)?(-unknown)?-linux(-gnu)?- There are more possibilities, but the above is known to find a compiler on Fedora and Ubuntu (which use linux-gnu-), and also detects the kernel.org cross compilers (which use linux-). This allows cross compiling with simply: # Ubuntu $ sudo apt install gcc-powerpc-linux-gnu # Fedora $ sudo dnf install gcc-powerpc64-linux-gnu $ make ARCH=powerpc defconfig $ make ARCH=powerpc -j 4 Inspired by arch/parisc/Makefile. Acked-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231206115548.1466874-4-mpe@ellerman.id.au diff dc5dac74 Fri Apr 07 08:17:49 MDT 2023 Nicholas Piggin <npiggin@gmail.com> powerpc/64: Add support to build with prefixed instructions Add an option to build kernel and module with prefixed instructions if the CPU and toolchain support it. This is not related to kernel support for userspace execution of prefixed instructions. Building with prefixed instructions breaks some extended inline asm memory addressing, for example it will provide immediates that exceed the range of simple load/store displacement. Whether this is a toolchain or a kernel asm problem remains to be seen. For now, these are replaced with simpler and less efficient direct register addressing when compiling with prefixed. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230408021752.862660-4-npiggin@gmail.com diff 78f09298 Tue Apr 04 04:28:47 MDT 2023 Michael Ellerman <mpe@ellerman.id.au> powerpc/64: Always build with 128-bit long double The amdgpu driver builds some of its code with hard-float enabled, whereas the rest of the kernel is built with soft-float. When building with 64-bit long double, if soft-float and hard-float objects are linked together, the build fails due to incompatible ABI tags. In the past there have been build errors in the amdgpu driver caused by this, some of those were due to bad intermingling of soft & hard-float code, but those issues have now all been fixed since commit 58ddbecb14c7 ("drm/amd/display: move remaining FPU code to dml folder"). However it's still possible for soft & hard-float objects to end up linked together, if the amdgpu driver is built-in to the kernel along with the test_emulate_step.c code, which uses soft-float. That happens in an allyesconfig build. Currently those build errors are avoided because the amdgpu driver is gated on 128-bit long double being enabled. But that's not a detail the amdgpu driver should need to be aware of, and if another driver starts using hard-float the same problem would occur. All versions of the 64-bit ABI specify that long-double is 128-bits. However some compilers, notably the kernel.org ones, are built to use 64-bit long double by default. Apart from this issue of soft vs hard-float, the kernel doesn't care what size long double is. In particular the kernel using 128-bit long double doesn't impact userspace's ability to use 64-bit long double, as musl does. So always build the 64-bit kernel with 128-bit long double. That should avoid any build errors due to the incompatible ABI tags. Excluding the code that uses soft/hard-float, the vmlinux is identical with/without the flag. It does mean any code which is incorrectly intermingling soft & hard-float code will build without error, so those bugs will need to be caught by testing rather than at build time. For more background see: - commit d11219ad53dc ("amdgpu: disable powerpc support for the newer display engine") - commit c653c591789b ("drm/amdgpu: Re-enable DCN for 64-bit powerpc") - https://lore.kernel.org/r/dab9cbd8-2626-4b99-8098-31fe76397d2d@app.fastmail.com Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org> Link: https://msgid.link/20230404102847.3303623-1-mpe@ellerman.id.au diff 4b2a9315 Thu Sep 22 21:30:04 MDT 2022 Nicholas Piggin <npiggin@gmail.com> powerpc/64s: POWER10 CPU Kconfig build option This adds basic POWER10_CPU option, which builds with -mcpu=power10. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220923033004.536127-1-npiggin@gmail.com diff 446cda1b Mon Jul 11 08:19:30 MDT 2022 Christophe Leroy <christophe.leroy@csgroup.eu> powerpc/32: Don't always pass -mcpu=powerpc to the compiler Since commit 4bf4f42a2feb ("powerpc/kbuild: Set default generic machine type for 32-bit compile"), when building a 32 bits kernel with a bi-arch version of GCC, or when building a book3s/32 kernel, the option -mcpu=powerpc is passed to GCC at all time, relying on it being eventually overriden by a subsequent -mcpu=xxxx. But when building the same kernel with a 32 bits only version of GCC, that is not done, relying on gcc being built with the expected default CPU. This logic has two problems. First, it is a bit fragile to rely on whether the GCC version is bi-arch or not, because today we can have bi-arch versions of GCC configured with a 32 bits default. Second, there are some versions of GCC which don't support -mcpu=powerpc, for instance for e500 SPE-only versions. So, stop relying on this approximative logic and allow the user to decide whether he/she wants to use the toolchain's default CPU or if he/she wants to set one, and allow only possible CPUs based on the selected target. Reported-by: Pali Rohár <pali@kernel.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Tested-by: Pali Rohár <pali@kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d4df724691351531bf46d685d654689e5dfa0d74.1657549153.git.christophe.leroy@csgroup.eu diff fd1feade Fri Jan 21 09:30:27 MST 2022 Christophe Leroy <christophe.leroy@csgroup.eu> powerpc/vdso: Merge vdso64 and vdso32 into a single directory merge vdso64 into vdso32 and rename it vdso. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4dbe05cc130f6a0858d09ac72e436c373cb08b70.1642782130.git.christophe.leroy@csgroup.eu diff 052c805a Sat Dec 12 09:54:30 MST 2020 Masahiro Yamada <masahiroy@kernel.org> kbuild: LD_VERSION redenomination Commit ccbef1674a15 ("Kbuild, lto: add ld-version and ld-ifversion macros") introduced scripts/ld-version.sh for GCC LTO. At that time, this script handled 5 version fields because GCC LTO needed the downstream binutils. (https://lkml.org/lkml/2014/4/8/272) The code snippet from the submitted patch was as follows: # We need HJ Lu's Linux binutils because mainline binutils does not # support mixing assembler and LTO code in the same ld -r object. # XXX check if the gcc plugin ld is the expected one too # XXX some Fedora binutils should also support it. How to check for that? ifeq ($(call ld-ifversion,-ge,22710001,y),y) ... However, GCC LTO was not merged into the mainline after all. (https://lkml.org/lkml/2014/4/8/272) So, the 4th and 5th fields were never used, and finally removed by commit 0d61ed17dd30 ("ld-version: Drop the 4th and 5th version components"). Since then, the last 4-digits returned by this script is always zeros. Remove the meaningless last 4-digits. This makes the version format consistent with GCC_VERSION, CLANG_VERSION, LLD_VERSION. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> diff 052c805a Sat Dec 12 09:54:30 MST 2020 Masahiro Yamada <masahiroy@kernel.org> kbuild: LD_VERSION redenomination Commit ccbef1674a15 ("Kbuild, lto: add ld-version and ld-ifversion macros") introduced scripts/ld-version.sh for GCC LTO. At that time, this script handled 5 version fields because GCC LTO needed the downstream binutils. (https://lkml.org/lkml/2014/4/8/272) The code snippet from the submitted patch was as follows: # We need HJ Lu's Linux binutils because mainline binutils does not # support mixing assembler and LTO code in the same ld -r object. # XXX check if the gcc plugin ld is the expected one too # XXX some Fedora binutils should also support it. How to check for that? ifeq ($(call ld-ifversion,-ge,22710001,y),y) ... However, GCC LTO was not merged into the mainline after all. (https://lkml.org/lkml/2014/4/8/272) So, the 4th and 5th fields were never used, and finally removed by commit 0d61ed17dd30 ("ld-version: Drop the 4th and 5th version components"). Since then, the last 4-digits returned by this script is always zeros. Remove the meaningless last 4-digits. This makes the version format consistent with GCC_VERSION, CLANG_VERSION, LLD_VERSION. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> diff 052c805a Sat Dec 12 09:54:30 MST 2020 Masahiro Yamada <masahiroy@kernel.org> kbuild: LD_VERSION redenomination Commit ccbef1674a15 ("Kbuild, lto: add ld-version and ld-ifversion macros") introduced scripts/ld-version.sh for GCC LTO. At that time, this script handled 5 version fields because GCC LTO needed the downstream binutils. (https://lkml.org/lkml/2014/4/8/272) The code snippet from the submitted patch was as follows: # We need HJ Lu's Linux binutils because mainline binutils does not # support mixing assembler and LTO code in the same ld -r object. # XXX check if the gcc plugin ld is the expected one too # XXX some Fedora binutils should also support it. How to check for that? ifeq ($(call ld-ifversion,-ge,22710001,y),y) ... However, GCC LTO was not merged into the mainline after all. (https://lkml.org/lkml/2014/4/8/272) So, the 4th and 5th fields were never used, and finally removed by commit 0d61ed17dd30 ("ld-version: Drop the 4th and 5th version components"). Since then, the last 4-digits returned by this script is always zeros. Remove the meaningless last 4-digits. This makes the version format consistent with GCC_VERSION, CLANG_VERSION, LLD_VERSION. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> diff 052c805a Sat Dec 12 09:54:30 MST 2020 Masahiro Yamada <masahiroy@kernel.org> kbuild: LD_VERSION redenomination Commit ccbef1674a15 ("Kbuild, lto: add ld-version and ld-ifversion macros") introduced scripts/ld-version.sh for GCC LTO. At that time, this script handled 5 version fields because GCC LTO needed the downstream binutils. (https://lkml.org/lkml/2014/4/8/272) The code snippet from the submitted patch was as follows: # We need HJ Lu's Linux binutils because mainline binutils does not # support mixing assembler and LTO code in the same ld -r object. # XXX check if the gcc plugin ld is the expected one too # XXX some Fedora binutils should also support it. How to check for that? ifeq ($(call ld-ifversion,-ge,22710001,y),y) ... However, GCC LTO was not merged into the mainline after all. (https://lkml.org/lkml/2014/4/8/272) So, the 4th and 5th fields were never used, and finally removed by commit 0d61ed17dd30 ("ld-version: Drop the 4th and 5th version components"). Since then, the last 4-digits returned by this script is always zeros. Remove the meaningless last 4-digits. This makes the version format consistent with GCC_VERSION, CLANG_VERSION, LLD_VERSION. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> diff 052c805a Sat Dec 12 09:54:30 MST 2020 Masahiro Yamada <masahiroy@kernel.org> kbuild: LD_VERSION redenomination Commit ccbef1674a15 ("Kbuild, lto: add ld-version and ld-ifversion macros") introduced scripts/ld-version.sh for GCC LTO. At that time, this script handled 5 version fields because GCC LTO needed the downstream binutils. (https://lkml.org/lkml/2014/4/8/272) The code snippet from the submitted patch was as follows: # We need HJ Lu's Linux binutils because mainline binutils does not # support mixing assembler and LTO code in the same ld -r object. # XXX check if the gcc plugin ld is the expected one too # XXX some Fedora binutils should also support it. How to check for that? ifeq ($(call ld-ifversion,-ge,22710001,y),y) ... However, GCC LTO was not merged into the mainline after all. (https://lkml.org/lkml/2014/4/8/272) So, the 4th and 5th fields were never used, and finally removed by commit 0d61ed17dd30 ("ld-version: Drop the 4th and 5th version components"). Since then, the last 4-digits returned by this script is always zeros. Remove the meaningless last 4-digits. This makes the version format consistent with GCC_VERSION, CLANG_VERSION, LLD_VERSION. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> diff 052c805a Sat Dec 12 09:54:30 MST 2020 Masahiro Yamada <masahiroy@kernel.org> kbuild: LD_VERSION redenomination Commit ccbef1674a15 ("Kbuild, lto: add ld-version and ld-ifversion macros") introduced scripts/ld-version.sh for GCC LTO. At that time, this script handled 5 version fields because GCC LTO needed the downstream binutils. (https://lkml.org/lkml/2014/4/8/272) The code snippet from the submitted patch was as follows: # We need HJ Lu's Linux binutils because mainline binutils does not # support mixing assembler and LTO code in the same ld -r object. # XXX check if the gcc plugin ld is the expected one too # XXX some Fedora binutils should also support it. How to check for that? ifeq ($(call ld-ifversion,-ge,22710001,y),y) ... However, GCC LTO was not merged into the mainline after all. (https://lkml.org/lkml/2014/4/8/272) So, the 4th and 5th fields were never used, and finally removed by commit 0d61ed17dd30 ("ld-version: Drop the 4th and 5th version components"). Since then, the last 4-digits returned by this script is always zeros. Remove the meaningless last 4-digits. This makes the version format consistent with GCC_VERSION, CLANG_VERSION, LLD_VERSION. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> |
/linux-master/arch/arm/ | ||
H A D | Makefile | diff 99497df5 Sat Dec 16 09:27:00 MST 2023 Dmitry Baryshkov <dmitry.baryshkov@linaro.org> ARM: qcom: merge remaining subplatforms into sensible Kconfig entry Three remaining Qualcomm platforms have special handling of the TEXT_OFFSET to reserve the memory at the beginnig of the system RAM, see the commit 9e775ad19f52 ("ARM: 7012/1: Set proper TEXT_OFFSET for newer MSMs"). This is required for older platforms like IPQ40xx, MSM8x60, MSM8960 and APQ8064 and is compatible with other 32-bit Qualcomm platforms. Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Link: https://lore.kernel.org/r/20231216162700.863456-4-dmitry.baryshkov@linaro.org Signed-off-by: Bjorn Andersson <andersson@kernel.org> diff e9faf9b0 Mon Jan 23 16:02:13 MST 2023 Nicolas Saenz Julienne <nsaenz@kernel.org> ARM: add multi_v7_lpae_defconfig The only missing configuration option preventing us from using multi_v7_defconfig with the Raspberry Pi 4 is ARM_LPAE. It's needed as the PCIe controller found on the SoC depends on 64bit addressing, yet can't be included as not all v7 boards support LPAE. Introduce multi_v7_lpae_defconfig, built off multi_v7_defconfig, which will avoid us having to duplicate and maintain multiple similar configurations. Needless to say the Raspberry Pi 4 is not the only platform that can benefit from this new configuration. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com> Link: https://lore.kernel.org/r/20230124110213.3221264-11-alexander.stein@ew.tq-group.com Signed-off-by: Arnd Bergmann <arnd@arndb.de> diff e9faf9b0 Mon Jan 23 16:02:13 MST 2023 Nicolas Saenz Julienne <nsaenz@kernel.org> ARM: add multi_v7_lpae_defconfig The only missing configuration option preventing us from using multi_v7_defconfig with the Raspberry Pi 4 is ARM_LPAE. It's needed as the PCIe controller found on the SoC depends on 64bit addressing, yet can't be included as not all v7 boards support LPAE. Introduce multi_v7_lpae_defconfig, built off multi_v7_defconfig, which will avoid us having to duplicate and maintain multiple similar configurations. Needless to say the Raspberry Pi 4 is not the only platform that can benefit from this new configuration. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com> Link: https://lore.kernel.org/r/20230124110213.3221264-11-alexander.stein@ew.tq-group.com Signed-off-by: Arnd Bergmann <arnd@arndb.de> diff 2cf1c348 Sun Jan 30 07:51:06 MST 2022 John Crispin <john@phrozen.org> ARM: Add basic support for Airoha EN7523 SoC EN7523 is an armv8 based silicon used inside broadband access type devices such as xPON and xDSL. It shares various silicon blocks with MediaTek silicon such as the MT7622. Add basic support for Airoha EN7523, enough for booting to console. The UART is basically 8250-compatible, except for the clock selection. A clock-frequency value is synthesized to get this to run at 115200 bps. Signed-off-by: John Crispin <john@phrozen.org> Signed-off-by: Bert Vermeulen <bert@biot.com> Signed-off-by: Felix Fietkau <nbd@nbd.name> Link: https://lore.kernel.org/r/20220130145116.88406-4-nbd@nbd.name Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com> diff 50596b75 Sat Sep 18 02:44:37 MDT 2021 Ard Biesheuvel <ardb@kernel.org> ARM: smp: Store current pointer in TPIDRURO register if available Now that the user space TLS register is assigned on every return to user space, we can use it to keep the 'current' pointer while running in the kernel. This removes the need to access it via thread_info, which is located at the base of the stack, but will be moved out of there in a subsequent patch. Use the __builtin_thread_pointer() helper when available - this will help GCC understand that reloading the value within the same function is not necessary, even when using the per-task stack protector (which also generates accesses via the TLS register). For example, the generated code below loads TPIDRURO only once, and uses it to access both the stack canary and the preempt_count fields. <do_one_initcall>: e92d 41f0 stmdb sp!, {r4, r5, r6, r7, r8, lr} ee1d 4f70 mrc 15, 0, r4, cr13, cr0, {3} 4606 mov r6, r0 b094 sub sp, #80 ; 0x50 f8d4 34e8 ldr.w r3, [r4, #1256] ; 0x4e8 <- stack canary 9313 str r3, [sp, #76] ; 0x4c f8d4 8004 ldr.w r8, [r4, #4] <- preempt count Co-developed-by: Keith Packard <keithpac@amazon.com> Signed-off-by: Keith Packard <keithpac@amazon.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com> diff 50596b75 Sat Sep 18 02:44:37 MDT 2021 Ard Biesheuvel <ardb@kernel.org> ARM: smp: Store current pointer in TPIDRURO register if available Now that the user space TLS register is assigned on every return to user space, we can use it to keep the 'current' pointer while running in the kernel. This removes the need to access it via thread_info, which is located at the base of the stack, but will be moved out of there in a subsequent patch. Use the __builtin_thread_pointer() helper when available - this will help GCC understand that reloading the value within the same function is not necessary, even when using the per-task stack protector (which also generates accesses via the TLS register). For example, the generated code below loads TPIDRURO only once, and uses it to access both the stack canary and the preempt_count fields. <do_one_initcall>: e92d 41f0 stmdb sp!, {r4, r5, r6, r7, r8, lr} ee1d 4f70 mrc 15, 0, r4, cr13, cr0, {3} 4606 mov r6, r0 b094 sub sp, #80 ; 0x50 f8d4 34e8 ldr.w r3, [r4, #1256] ; 0x4e8 <- stack canary 9313 str r3, [sp, #76] ; 0x4c f8d4 8004 ldr.w r8, [r4, #4] <- preempt count Co-developed-by: Keith Packard <keithpac@amazon.com> Signed-off-by: Keith Packard <keithpac@amazon.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com> diff cc611137 Fri Jan 15 08:51:24 MST 2021 Uwe Kleine-König <u.kleine-koenig@pengutronix.de> ARM: drop efm32 platform I didn't touch this code since it served as a platform to introduce ARMv7-M support to Linux. The only known machine that runs Linux has only 4 MiB of RAM (that originally only exists to hold the display's framebuffer). There are no known users and no further use foreseeable, so drop the code. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20210115155130.185010-2-u.kleine-koenig@pengutronix.de' Signed-off-by: Arnd Bergmann <arnd@arndb.de> diff 4cb5d9ec Wed Apr 10 02:47:28 MDT 2019 Thierry Reding <treding@nvidia.com> firmware: Move Trusted Foundations support Move the Trusted Foundations support out of arch/arm/firmware and into drivers/firmware where most other firmware support implementations are located. Signed-off-by: Thierry Reding <treding@nvidia.com> diff 4e2648db Tue Oct 18 13:11:23 MDT 2016 Russell King <rmk+kernel@armlinux.org.uk> ARM: remove indirection of asm/mach-types.h Arrange for mach-types.h to be directly generated in the relevant path, so we don't need a one-liner file in arch/arm/include/asm/. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> diff 1847119d Mon Apr 25 02:49:13 MDT 2016 Vladimir Murzin <vladimir.murzin@arm.com> ARM: vexpress/mps2: introduce MPS2 platform The Cortex-M Prototyping System (or V2M-MPS2) is designed for prototyping and evaluation Cortex-M family of processors including the latest Cortex-M7 It comes with a range of useful peripherals including 8MB single cycle SRAM, 16MB PSRAM, Ethernet, QSVGA touch screen panel, 4bit RGB VGA connector, Audio, SPI and GPIO. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> |
/linux-master/ | ||
H A D | Makefile | diff 4cece764 Sun Mar 24 15:10:05 MDT 2024 Linus Torvalds <torvalds@linux-foundation.org> Linux 6.9-rc1 diff 50a33998 Fri Mar 01 04:21:07 MST 2024 Masahiro Yamada <masahiroy@kernel.org> kbuild: fix inconsistent indentation in top Makefile Commit 3b9ab248bc45 ("kbuild: use 4-space indentation when followed by conditionals") introduced inconsistent indentation because it deliberately touched only the conditional directives to minimize the change set. This commit reformats some blocks in the top Makefile so they are consistently indented with 4 spaces. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> diff 50a33998 Fri Mar 01 04:21:07 MST 2024 Masahiro Yamada <masahiroy@kernel.org> kbuild: fix inconsistent indentation in top Makefile Commit 3b9ab248bc45 ("kbuild: use 4-space indentation when followed by conditionals") introduced inconsistent indentation because it deliberately touched only the conditional directives to minimize the change set. This commit reformats some blocks in the top Makefile so they are consistently indented with 4 spaces. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> diff 3b9ab248 Thu Feb 01 18:31:42 MST 2024 Masahiro Yamada <masahiroy@kernel.org> kbuild: use 4-space indentation when followed by conditionals GNU Make manual [1] clearly forbids a tab at the beginning of the conditional directive line: "Extra spaces are allowed and ignored at the beginning of the conditional directive line, but a tab is not allowed." This will not work for the next release of GNU Make, hence commit 82175d1f9430 ("kbuild: Replace tabs with spaces when followed by conditionals") replaced the inappropriate tabs with 8 spaces. However, the 8-space indentation cannot be visually distinguished. Linus suggested 2-4 spaces for those nested if-statements. [2] This commit redoes the replacement with 4 spaces. [1]: https://www.gnu.org/software/make/manual/make.html#Conditional-Syntax [2]: https://lore.kernel.org/all/CAHk-=whJKZNZWsa-VNDKafS_VfY4a5dAjG-r8BZgWk_a-xSepw@mail.gmail.com/ Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 3b9ab248 Thu Feb 01 18:31:42 MST 2024 Masahiro Yamada <masahiroy@kernel.org> kbuild: use 4-space indentation when followed by conditionals GNU Make manual [1] clearly forbids a tab at the beginning of the conditional directive line: "Extra spaces are allowed and ignored at the beginning of the conditional directive line, but a tab is not allowed." This will not work for the next release of GNU Make, hence commit 82175d1f9430 ("kbuild: Replace tabs with spaces when followed by conditionals") replaced the inappropriate tabs with 8 spaces. However, the 8-space indentation cannot be visually distinguished. Linus suggested 2-4 spaces for those nested if-statements. [2] This commit redoes the replacement with 4 spaces. [1]: https://www.gnu.org/software/make/manual/make.html#Conditional-Syntax [2]: https://lore.kernel.org/all/CAHk-=whJKZNZWsa-VNDKafS_VfY4a5dAjG-r8BZgWk_a-xSepw@mail.gmail.com/ Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 3b9ab248 Thu Feb 01 18:31:42 MST 2024 Masahiro Yamada <masahiroy@kernel.org> kbuild: use 4-space indentation when followed by conditionals GNU Make manual [1] clearly forbids a tab at the beginning of the conditional directive line: "Extra spaces are allowed and ignored at the beginning of the conditional directive line, but a tab is not allowed." This will not work for the next release of GNU Make, hence commit 82175d1f9430 ("kbuild: Replace tabs with spaces when followed by conditionals") replaced the inappropriate tabs with 8 spaces. However, the 8-space indentation cannot be visually distinguished. Linus suggested 2-4 spaces for those nested if-statements. [2] This commit redoes the replacement with 4 spaces. [1]: https://www.gnu.org/software/make/manual/make.html#Conditional-Syntax [2]: https://lore.kernel.org/all/CAHk-=whJKZNZWsa-VNDKafS_VfY4a5dAjG-r8BZgWk_a-xSepw@mail.gmail.com/ Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 66242cfa Mon Nov 20 11:37:19 MST 2023 Heiko Carstens <hca@linux.ibm.com> checkstack: allow to pass MINSTACKSIZE parameter The checkstack script omits all functions with a stack usage of less than 100 bytes. However the script already has support for a parameter which allows to override the default, but it cannot be set with $ make checkstack Add a MINSTACKSIZE parameter which allows to change the default. This might be useful in order to print the stack usage of all functions, or only those with large stack usage: $ make checkstack MINSTACKSIZE=0 $ make checkstack MINSTACKSIZE=800 Link: https://lkml.kernel.org/r/20231120183719.2188479-4-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Cc: Maninder Singh <maninder1.s@samsung.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> diff 4e3feaad Tue Jan 24 09:19:28 MST 2023 Nathan Chancellor <nathan@kernel.org> powerpc/vdso: Filter clang's auto var init zero enabler when linking After commit 8d9acfce3332 ("kbuild: Stop using '-Qunused-arguments' with clang"), the PowerPC vDSO shows the following error with clang-13 and older when CONFIG_INIT_STACK_ALL_ZERO is enabled: clang: error: argument unused during compilation: '-enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang' [-Werror,-Wunused-command-line-argument] clang-14 added a change to make sure this flag never triggers -Wunused-command-line-argument, so it is fixed with newer releases. For older releases that the kernel still supports building with, just filter out this flag, as has been done for other flags. Fixes: f0a42fbab447 ("powerpc/vdso: Improve linker flags") Fixes: 8d9acfce3332 ("kbuild: Stop using '-Qunused-arguments' with clang") Link: https://github.com/llvm/llvm-project/commit/ca6d5813d17598cd180995fb3bdfca00f364475f Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> diff 4ec5183e Sun Feb 05 14:13:28 MST 2023 Linus Torvalds <torvalds@linux-foundation.org> Linux 6.2-rc7 diff 4bf73588 Mon Dec 05 14:48:19 MST 2022 Dmitry Goncharov <dgoncharov@users.sf.net> kbuild: Port silent mode detection to future gnu make. Port silent mode detection to the future (post make-4.4) versions of gnu make. Makefile contains the following piece of make code to detect if option -s is specified on the command line. ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),) This code is executed by make at parse time and assumes that MAKEFLAGS does not contain command line variable definitions. Currently if the user defines a=s on the command line, then at build only time MAKEFLAGS contains " -- a=s". However, starting with commit dc2d963989b96161472b2cd38cef5d1f4851ea34 MAKEFLAGS contains command line definitions at both parse time and build time. This '-s' detection code then confuses a command line variable definition which contains letter 's' with option -s. $ # old make $ make net/wireless/ocb.o a=s CALL scripts/checksyscalls.sh DESCEND objtool $ # this a new make which defines makeflags at parse time $ ~/src/gmake/make/l64/make net/wireless/ocb.o a=s $ We can see here that the letter 's' from 'a=s' was confused with -s. This patch checks for presence of -s using a method recommended by the make manual here https://www.gnu.org/software/make/manual/make.html#Testing-Flags. Link: https://lists.gnu.org/archive/html/bug-make/2022-11/msg00190.html Reported-by: Jan Palus <jpalus+gnu@fastmail.com> Signed-off-by: Dmitry Goncharov <dgoncharov@users.sf.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> |
Completed in 1990 milliseconds