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3f1a9bc5 |
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30-Mar-2024 |
Masahiro Yamada <masahiroy@kernel.org> |
x86/build: Use obj-y to descend into arch/x86/virt/ Commit c33621b4c5ad ("x86/virt/tdx: Wire up basic SEAMCALL functions") introduced a new instance of core-y instead of the standardized obj-y syntax. X86 Makefiles descend into subdirectories of arch/x86/virt inconsistently; into arch/x86/virt/ via core-y defined in arch/x86/Makefile, but into arch/x86/virt/svm/ via obj-y defined in arch/x86/Kbuild. This is problematic when you build a single object in parallel because multiple threads attempt to build the same file. $ make -j$(nproc) arch/x86/virt/vmx/tdx/seamcall.o [ snip ] AS arch/x86/virt/vmx/tdx/seamcall.o AS arch/x86/virt/vmx/tdx/seamcall.o fixdep: error opening file: arch/x86/virt/vmx/tdx/.seamcall.o.d: No such file or directory make[4]: *** [scripts/Makefile.build:362: arch/x86/virt/vmx/tdx/seamcall.o] Error 2 Use the obj-y syntax, as it works correctly. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240330060554.18524-1-masahiroy@kernel.org
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22d3da07 |
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25-Jan-2024 |
Nathan Chancellor <nathan@kernel.org> |
x86: drop stack-alignment plugin opt Now that the minimum supported version of LLVM for building the kernel has been bumped to 13.0.1, the inner ifeq statement is always false, as the build will fail during the configuration stage for older LLVM versions. This effectively reverts part of commit b33fff07e3e3 ("x86, build: allow LTO to be selected") and its follow up fix, commit 2398ce80152a ("x86, lto: Pass -stack-alignment only on LLD < 13.0.0"). Link: https://lkml.kernel.org/r/20240125-bump-min-llvm-ver-to-13-0-1-v1-3-f5ff9bda41c5@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Conor Dooley <conor@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Nicolas Schier <nicolas@fjasle.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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f82811e2 |
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20-Oct-2023 |
Jamie Cunliffe <Jamie.Cunliffe@arm.com> |
rust: Refactor the build target to allow the use of builtin targets Eventually we want all architectures to be using the target as defined by rustc. However currently some architectures can't do that and are using the target.json specification. This puts in place the foundation to allow the use of the builtin target definition or a target.json specification. Signed-off-by: Jamie Cunliffe <Jamie.Cunliffe@arm.com> Acked-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231020155056.3495121-2-Jamie.Cunliffe@arm.com [catalin.marinas@arm.com: squashed loongarch ifneq fix from WANG Rui] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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289d0a47 |
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21-Nov-2023 |
Masahiro Yamada <masahiroy@kernel.org> |
x86/vdso: Use CONFIG_COMPAT_32 to specify vdso32 In arch/x86/Kconfig, COMPAT_32 is defined as (IA32_EMULATION || X86_32). Use it to eliminate redundancy in Makefile. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20231121235701.239606-5-masahiroy@kernel.org
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2afa7994 |
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12-Jan-2024 |
Thomas Zimmermann <tzimmermann@suse.de> |
x86/setup: Move internal setup_data structures into setup_data.h Move struct_efi_setup_data in order to unify duplicated definition of the data structure in a single place. Also silence clang's warnings about GNU extensions in real-mode code which might occur from the changed includes. [ bp: Massage commit message. ] Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240112095000.8952-3-tzimmermann@suse.de
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0911b8c5 |
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21-Nov-2023 |
Breno Leitao <leitao@debian.org> |
x86/bugs: Rename CONFIG_RETHUNK => CONFIG_MITIGATION_RETHUNK Step 10/10 of the namespace unification of CPU mitigations related Kconfig options. [ mingo: Added one more case. ] Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20231121160740.1249350-11-leitao@debian.org
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7b75782f |
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21-Nov-2023 |
Breno Leitao <leitao@debian.org> |
x86/bugs: Rename CONFIG_SLS => CONFIG_MITIGATION_SLS Step 6/10 of the namespace unification of CPU mitigations related Kconfig options. Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20231121160740.1249350-7-leitao@debian.org
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aefb2f2e |
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21-Nov-2023 |
Breno Leitao <leitao@debian.org> |
x86/bugs: Rename CONFIG_RETPOLINE => CONFIG_MITIGATION_RETPOLINE Step 5/10 of the namespace unification of CPU mitigations related Kconfig options. [ mingo: Converted a few more uses in comments/messages as well. ] Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ariel Miculas <amiculas@cisco.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20231121160740.1249350-6-leitao@debian.org
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3b9ab248 |
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01-Feb-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>
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82175d1f |
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28-Jan-2024 |
Dmitry Goncharov <dgoncharov@users.sf.net> |
kbuild: Replace tabs with spaces when followed by conditionals This is needed for the future (post make-4.4.1) versions of gnu make. Starting from https://git.savannah.gnu.org/cgit/make.git/commit/?id=07fcee35f058a876447c8a021f9eb1943f902534 gnu make won't allow conditionals to follow recipe prefix. For example there is a tab followed by ifeq on line 324 in the root Makefile. With the new make this conditional causes the following $ make cpu.o /home/dgoncharov/src/linux-kbuild/Makefile:2063: *** missing 'endif'. Stop. make: *** [Makefile:240: __sub-make] Error 2 This patch replaces tabs followed by conditionals with 8 spaces. See https://savannah.gnu.org/bugs/?64185 and https://savannah.gnu.org/bugs/?64259 for details. Signed-off-by: Dmitry Goncharov <dgoncharov@users.sf.net> Reported-by: Martin Dorey <martin.dorey@hitachivantara.com> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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56769ba4 |
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14-Oct-2023 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: unify vdso_install rules Currently, there is no standard implementation for vdso_install, leading to various issues: 1. Code duplication Many architectures duplicate similar code just for copying files to the install destination. Some architectures (arm, sparc, x86) create build-id symlinks, introducing more code duplication. 2. Unintended updates of in-tree build artifacts The vdso_install rule depends on the vdso files to install. It may update in-tree build artifacts. This can be problematic, as explained in commit 19514fc665ff ("arm, kbuild: make "make install" not depend on vmlinux"). 3. Broken code in some architectures Makefile code is often copied from one architecture to another without proper adaptation. 'make vdso_install' for parisc does not work. 'make vdso_install' for s390 installs vdso64, but not vdso32. To address these problems, this commit introduces a generic vdso_install rule. Architectures that support vdso_install need to define vdso-install-y in arch/*/Makefile. vdso-install-y lists the files to install. For example, arch/x86/Makefile looks like this: vdso-install-$(CONFIG_X86_64) += arch/x86/entry/vdso/vdso64.so.dbg vdso-install-$(CONFIG_X86_X32_ABI) += arch/x86/entry/vdso/vdsox32.so.dbg vdso-install-$(CONFIG_X86_32) += arch/x86/entry/vdso/vdso32.so.dbg vdso-install-$(CONFIG_IA32_EMULATION) += arch/x86/entry/vdso/vdso32.so.dbg These files will be installed to $(MODLIB)/vdso/ with the .dbg suffix, if exists, stripped away. vdso-install-y can optionally take the second field after the colon separator. This is needed because some architectures install a vdso file as a different base name. The following is a snippet from arch/arm64/Makefile. vdso-install-$(CONFIG_COMPAT_VDSO) += arch/arm64/kernel/vdso32/vdso.so.dbg:vdso32.so This will rename vdso.so.dbg to vdso32.so during installation. If such architectures change their implementation so that the base names match, this workaround will go away. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Sven Schnelle <svens@linux.ibm.com> # s390 Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Reviewed-by: Guo Ren <guoren@kernel.org> Acked-by: Helge Deller <deller@gmx.de> # parisc Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
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#
c33621b4 |
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15-Aug-2023 |
Kai Huang <kai.huang@intel.com> |
x86/virt/tdx: Wire up basic SEAMCALL functions Intel Trust Domain Extensions (TDX) protects guest VMs from malicious host and certain physical attacks. A CPU-attested software module called 'the TDX module' runs inside a new isolated memory range as a trusted hypervisor to manage and run protected VMs. TDX introduces a new CPU mode: Secure Arbitration Mode (SEAM). This mode runs only the TDX module itself or other code to load the TDX module. The host kernel communicates with SEAM software via a new SEAMCALL instruction. This is conceptually similar to a guest->host hypercall, except it is made from the host to SEAM software instead. The TDX module establishes a new SEAMCALL ABI which allows the host to initialize the module and to manage VMs. The SEAMCALL ABI is very similar to the TDCALL ABI and leverages much TDCALL infrastructure. Wire up basic functions to make SEAMCALLs for the basic support of running TDX guests: __seamcall(), __seamcall_ret(), and __seamcall_saved_ret() for TDH.VP.ENTER. All SEAMCALLs involved in the basic TDX support don't use "callee-saved" registers as input and output, except the TDH.VP.ENTER. To start to support TDX, create a new arch/x86/virt/vmx/tdx/tdx.c for TDX host kernel support. Add a new Kconfig option CONFIG_INTEL_TDX_HOST to opt-in TDX host kernel support (to distinguish with TDX guest kernel support). So far only KVM uses TDX. Make the new config option depend on KVM_INTEL. Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Isaku Yamahata <isaku.yamahata@intel.com> Link: https://lore.kernel.org/all/4db7c3fc085e6af12acc2932294254ddb3d320b3.1692096753.git.kai.huang%40intel.com
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6a5c032c |
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09-Oct-2023 |
Matthew Maurer <mmaurer@google.com> |
x86: Enable IBT in Rust if enabled in C These flags are not made conditional on compiler support because at the moment exactly one version of rustc supported, and that one supports these flags. Building without these additional flags will manifest as objtool printing a large number of errors about missing ENDBR and if CFI is enabled (not currently possible) will result in incorrectly structured function prefixes. Signed-off-by: Matthew Maurer <mmaurer@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: "Peter Zijlstra (Intel)" <peterz@infradead.org> Link: https://lore.kernel.org/r/20231009224347.2076221-1-mmaurer@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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b3bee1e7 |
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27-Sep-2023 |
Alexey Dobriyan <adobriyan@gmail.com> |
x86/boot: Compile boot code with -std=gnu11 too Use -std=gnu11 for consistency with main kernel code. It doesn't seem to change anything in vmlinux. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: H. Peter Anvin (Intel) <hpa@zytor.com> Link: https://lore.kernel.org/r/2058761e-12a4-4b2f-9690-3c3c1c9902a5@p183
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feec5e1f |
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31-Aug-2023 |
Kees Cook <keescook@chromium.org> |
kbuild: Show marked Kconfig fragments in "help" Currently the Kconfig fragments in kernel/configs and arch/*/configs that aren't used internally aren't discoverable through "make help", which consists of hard-coded lists of config fragments. Instead, list all the fragment targets that have a "# Help: " comment prefix so the targets can be generated dynamically. Add logic to the Makefile to search for and display the fragment and comment. Add comments to fragments that are intended to be direct targets. Signed-off-by: Kees Cook <keescook@chromium.org> Co-developed-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Reviewed-by: Nicolas Schier <nicolas@fjasle.eu> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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55bffc81 |
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19-Jul-2023 |
Javier Martinez Canillas <javierm@redhat.com> |
fbdev: Split frame buffer support in FB and FB_CORE symbols Currently the CONFIG_FB option has to be enabled even if no legacy fbdev drivers are needed (e.g: only to have support for framebuffer consoles). The DRM subsystem has a fbdev emulation layer, but depends on CONFIG_FB and so it can only be enabled if that dependency is enabled as well. That means fbdev drivers have to be explicitly disabled if users want to enable CONFIG_FB, only to use fbcon and/or the DRM fbdev emulation layer. This patch introduces a non-visible CONFIG_FB_CORE symbol that could be enabled just to have core support needed for CONFIG_DRM_FBDEV_EMULATION, allowing CONFIG_FB to be disabled (and automatically disabling all the fbdev drivers). Nothing from fb_backlight.o and fbmon.o is used by the DRM fbdev emulation layer so these two objects can be compiled out when CONFIG_FB is disabled. Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Helge Deller <deller@gmx.de> Link: https://patchwork.freedesktop.org/patch/msgid/20230719081544.741051-4-javierm@redhat.com
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b9f174c8 |
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13-Jun-2023 |
Omar Sandoval <osandov@fb.com> |
x86/unwind/orc: Add ELF section with ORC version identifier Commits ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC metadata") and fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in two") changed the ORC format. Although ORC is internal to the kernel, it's the only way for external tools to get reliable kernel stack traces on x86-64. In particular, the drgn debugger [1] uses ORC for stack unwinding, and these format changes broke it [2]. As the drgn maintainer, I don't care how often or how much the kernel changes the ORC format as long as I have a way to detect the change. It suffices to store a version identifier in the vmlinux and kernel module ELF files (to use when parsing ORC sections from ELF), and in kernel memory (to use when parsing ORC from a core dump+symbol table). Rather than hard-coding a version number that needs to be manually bumped, Peterz suggested hashing the definitions from orc_types.h. If there is a format change that isn't caught by this, the hashing script can be updated. This patch adds an .orc_header allocated ELF section containing the 20-byte hash to vmlinux and kernel modules, along with the corresponding __start_orc_header and __stop_orc_header symbols in vmlinux. 1: https://github.com/osandov/drgn 2: https://github.com/osandov/drgn/issues/303 Fixes: ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC metadata") Fixes: fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in two") Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Link: https://lkml.kernel.org/r/aef9c8dc43915b886a8c48509a12ec1b006ca1ca.1686690801.git.osandov@osandov.com
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f9bb7f6a |
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15-Feb-2023 |
Arnd Bergmann <arnd@arndb.de> |
x86/build: Make 64-bit defconfig the default Running 'make ARCH=x86 defconfig' on anything other than an x86_64 machine currently results in a 32-bit build, which is rarely what anyone wants these days. Change the default so that the 64-bit config gets used unless the user asks for i386_defconfig, uses ARCH=i386 or runs on a system that "uname -m" identifies as i386/i486/i586/i686. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230215091706.1623070-1-arnd@kernel.org
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27b5de62 |
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20-Jan-2023 |
Nathan Chancellor <nathan@kernel.org> |
x86/build: Move '-mindirect-branch-cs-prefix' out of GCC-only block LLVM 16 will have support for this flag so move it out of the GCC-only block to allow LLVM builds to take advantage of it. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://github.com/ClangBuiltLinux/linux/issues/1665 Link: https://github.com/llvm/llvm-project/commit/6f867f9102838ebe314c1f3661fdf95700386e5a Link: https://lore.kernel.org/r/20230120165826.2469302-1-nathan@kernel.org
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fccb3d3e |
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10-Dec-2022 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: add test-{ge,gt,le,lt} macros GNU Make 4.4 introduced $(intcmp ...), which is useful to compare two integers without forking a new process. Add test-{ge,gt,le,lt} macros, which work more efficiently with GNU Make >= 4.4. For older Make versions, they fall back to the 'test' shell command. The first two parameters to $(intcmp ...) must not be empty. To avoid the syntax error, I appended '0' to them. Fortunately, '00' is treated as '0'. This is needed because CONFIG options may expand to an empty string when the kernel configuration is not included. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> # RISC-V Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
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931ab636 |
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27-Oct-2022 |
Peter Zijlstra <peterz@infradead.org> |
x86/ibt: Implement FineIBT Implement an alternative CFI scheme that merges both the fine-grained nature of kCFI but also takes full advantage of the coarse grained hardware CFI as provided by IBT. To contrast: kCFI is a pure software CFI scheme and relies on being able to read text -- specifically the instruction *before* the target symbol, and does the hash validation *before* doing the call (otherwise control flow is compromised already). FineIBT is a software and hardware hybrid scheme; by ensuring every branch target starts with a hash validation it is possible to place the hash validation after the branch. This has several advantages: o the (hash) load is avoided; no memop; no RX requirement. o IBT WAIT-FOR-ENDBR state is a speculation stop; by placing the hash validation in the immediate instruction after the branch target there is a minimal speculation window and the whole is a viable defence against SpectreBHB. o Kees feels obliged to mention it is slightly more vulnerable when the attacker can write code. Obviously this patch relies on kCFI, but additionally it also relies on the padding from the call-depth-tracking patches. It uses this padding to place the hash-validation while the call-sites are re-written to modify the indirect target to be 16 bytes in front of the original target, thus hitting this new preamble. Notably, there is no hardware that needs call-depth-tracking (Skylake) and supports IBT (Tigerlake and onwards). Suggested-by: Joao Moreira (Intel) <joao@overdrivepizza.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221027092842.634714496@infradead.org
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bea75b33 |
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15-Sep-2022 |
Thomas Gleixner <tglx@linutronix.de> |
x86/Kconfig: Introduce function padding Now that all functions are 16 byte aligned, add 16 bytes of NOP padding in front of each function. This prepares things for software call stack tracking and kCFI/FineIBT. This significantly increases kernel .text size, around 5.1% on a x86_64-defconfig-ish build. However, per the random access argument used for alignment, these 16 extra bytes are code that wouldn't be used. Performance measurements back this up by showing no significant performance regressions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111146.950884492@infradead.org
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ce697cce |
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24-Sep-2022 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: remove head-y syntax Kbuild puts the objects listed in head-y at the head of vmlinux. Conventionally, we do this for head*.S, which contains the kernel entry point. A counter approach is to control the section order by the linker script. Actually, the code marked as __HEAD goes into the ".head.text" section, which is placed before the normal ".text" section. I do not know if both of them are needed. From the build system perspective, head-y is not mandatory. If you can achieve the proper code placement by the linker script only, it would be cleaner. I collected the current head-y objects into head-object-list.txt. It is a whitelist. My hope is it will be reduced in the long run. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
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09498135 |
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03-Aug-2022 |
Miguel Ojeda <ojeda@kernel.org> |
x86: enable initial Rust support Note that only x86_64 is covered and not all features nor mitigations are handled, but it is enough as a starting point and showcases the basics needed to add Rust support for a new architecture. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com> Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com> Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com> Co-developed-by: David Gow <davidgow@google.com> Signed-off-by: David Gow <davidgow@google.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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a0a12c3e |
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19-Aug-2022 |
Nick Desaulniers <ndesaulniers@google.com> |
asm goto: eradicate CC_HAS_ASM_GOTO GCC has supported asm goto since 4.5, and Clang has since version 9.0.0. The minimum supported versions of these tools for the build according to Documentation/process/changes.rst are 5.1 and 11.0.0 respectively. Remove the feature detection script, Kconfig option, and clean up some fallback code that is no longer supported. The removed script was also testing for a GCC specific bug that was fixed in the 4.7 release. Also remove workarounds for bpftrace using clang older than 9.0.0, since other BPF backend fixes are required at this point. Link: https://lore.kernel.org/lkml/CAK7LNATSr=BXKfkdW8f-H5VT_w=xBpT2ZQcZ7rm6JfkdE+QnmA@mail.gmail.com/ Link: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637 Acked-by: Borislav Petkov <bp@suse.de> Suggested-by: Masahiro Yamada <masahiroy@kernel.org> Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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efc72a66 |
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18-Jul-2022 |
Josh Poimboeuf <jpoimboe@kernel.org> |
lkdtm: Disable return thunks in rodata.c The following warning was seen: WARNING: CPU: 0 PID: 0 at arch/x86/kernel/alternative.c:557 apply_returns (arch/x86/kernel/alternative.c:557 (discriminator 1)) Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.19.0-rc4-00008-gee88d363d156 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014 RIP: 0010:apply_returns (arch/x86/kernel/alternative.c:557 (discriminator 1)) Code: ff ff 74 cb 48 83 c5 04 49 39 ee 0f 87 81 fe ff ff e9 22 ff ff ff 0f 0b 48 83 c5 04 49 39 ee 0f 87 6d fe ff ff e9 0e ff ff ff <0f> 0b 48 83 c5 04 49 39 ee 0f 87 59 fe ff ff e9 fa fe ff ff 48 89 The warning happened when apply_returns() failed to convert "JMP __x86_return_thunk" to RET. It was instead a JMP to nowhere, due to the thunk relocation not getting resolved. That rodata.o code is objcopy'd to .rodata, and later memcpy'd, so relocations don't work (and are apparently silently ignored). LKDTM is only used for testing, so the naked RET should be fine. So just disable return thunks for that file. While at it, disable objtool and KCSAN for the file. Fixes: 0b53c374b9ef ("x86/retpoline: Use -mfunction-return") Reported-by: kernel test robot <oliver.sang@intel.com> Debugged-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/lkml/Ys58BxHxoDZ7rfpr@xsang-OptiPlex-9020/
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f43b9876 |
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27-Jun-2022 |
Peter Zijlstra <peterz@infradead.org> |
x86/retbleed: Add fine grained Kconfig knobs Do fine-grained Kconfig for all the various retbleed parts. NOTE: if your compiler doesn't support return thunks this will silently 'upgrade' your mitigation to IBPB, you might not like this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de>
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0b53c374 |
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14-Jun-2022 |
Peter Zijlstra <peterz@infradead.org> |
x86/retpoline: Use -mfunction-return Utilize -mfunction-return=thunk-extern when available to have the compiler replace RET instructions with direct JMPs to the symbol __x86_return_thunk. This does not affect assembler (.S) sources, only C sources. -mfunction-return=thunk-extern has been available since gcc 7.3 and clang 15. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Borislav Petkov <bp@suse.de>
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f774f5bb |
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02-May-2022 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: factor out the common installation code into scripts/install.sh Many architectures have similar install.sh scripts. The first half is really generic; it verifies that the kernel image and System.map exist, then executes ~/bin/${INSTALLKERNEL} or /sbin/${INSTALLKERNEL} if available. The second half is kind of arch-specific; it copies the kernel image and System.map to the destination, but the code is slightly different. Factor out the generic part into scripts/install.sh. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <n.schier@avm.de>
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9b5a7f4a |
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31-Mar-2022 |
Dave Hansen <dave.hansen@linux.intel.com> |
x86/configs: Add x86 debugging Kconfig fragment plus docs The kernel has a wide variety of debugging options to help catch and squash bugs. However, new debugging is added all the time and the existing options can be hard to find. Add a Kconfig fragment with the debugging options which tip maintainers expect to be used to test contributions. This should make it easier for contributors to test their code and find issues before submission. [ bp: Add to "make help" output, fix DEBUG_INFO selection as pointed out by Nathan Chancellor <nathan@kernel.org>. ] Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220331175728.299103A0@davehans-spike.ostc.intel.com
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83a44a4f |
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14-Mar-2022 |
Masahiro Yamada <masahiroy@kernel.org> |
x86: Remove toolchain check for X32 ABI capability Commit 0bf6276392e9 ("x32: Warn and disable rather than error if binutils too old") added a small test in arch/x86/Makefile because binutils 2.22 or newer is needed to properly support elf32-x86-64. This check is no longer necessary, as the minimum supported version of binutils is 2.23, which is enforced at configuration time with scripts/min-tool-version.sh. Remove this check and replace all uses of CONFIG_X86_X32 with CONFIG_X86_X32_ABI, as two symbols are no longer necessary. [nathan: Rebase, fix up a few places where CONFIG_X86_X32 was still used, and simplify commit message to satisfy -tip requirements] Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220314194842.3452-2-nathan@kernel.org
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156ff4a5 |
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08-Mar-2022 |
Peter Zijlstra <peterz@infradead.org> |
x86/ibt: Base IBT bits Add Kconfig, Makefile and basic instruction support for x86 IBT. (Ab)use __DISABLE_EXPORTS to disable IBT since it's already employed to mark compressed and purgatory. Additionally mark realmode with it as well to avoid inserting ENDBR instructions there. While ENDBR is technically a NOP, inserting them was causing some grief due to code growth. There's also a problem with using __noendbr in code compiled without -fcf-protection=branch. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154317.519875203@infradead.org
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e463a09a |
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04-Dec-2021 |
Peter Zijlstra <peterz@infradead.org> |
x86: Add straight-line-speculation mitigation Make use of an upcoming GCC feature to mitigate straight-line-speculation for x86: https://gcc.gnu.org/g:53a643f8568067d7700a9f2facc8ba39974973d3 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102952 https://bugs.llvm.org/show_bug.cgi?id=52323 It's built tested on x86_64-allyesconfig using GCC-12 and GCC-11. Maintenance overhead of this should be fairly low due to objtool validation. Size overhead of all these additional int3 instructions comes to: text data bss dec hex filename 22267751 6933356 2011368 31212475 1dc43bb defconfig-build/vmlinux 22804126 6933356 1470696 31208178 1dc32f2 defconfig-build/vmlinux.sls Or roughly 2.4% additional text. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20211204134908.140103474@infradead.org
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68cf4f2a |
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19-Nov-2021 |
Peter Zijlstra <peterz@infradead.org> |
x86: Use -mindirect-branch-cs-prefix for RETPOLINE builds In order to further enable commit: bbe2df3f6b6d ("x86/alternative: Try inline spectre_v2=retpoline,amd") add the new GCC flag -mindirect-branch-cs-prefix: https://gcc.gnu.org/g:2196a681d7810ad8b227bf983f38ba716620545e https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102952 https://bugs.llvm.org/show_bug.cgi?id=52323 to RETPOLINE=y builds. This should allow fully inlining retpoline,amd for GCC builds. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lkml.kernel.org/r/20211119165630.276205624@infradead.org
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b2f825bf |
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19-Nov-2021 |
Peter Zijlstra <peterz@infradead.org> |
x86: Move RETPOLINE*_CFLAGS to arch Makefile Currently, RETPOLINE*_CFLAGS are defined in the top-level Makefile but only x86 makes use of them. Move them there. If ever another architecture finds the need, it can be reconsidered. [ bp: Massage a bit. ] Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lkml.kernel.org/r/20211119165630.219152765@infradead.org
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8212f898 |
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13-Oct-2021 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: use more subdir- for visiting subdirectories while cleaning Documentation/kbuild/makefiles.rst suggests to use "archclean" for cleaning arch/$(SRCARCH)/boot/, but it is not a hard requirement. Since commit d92cc4d51643 ("kbuild: require all architectures to have arch/$(SRCARCH)/Kbuild"), we can use the "subdir- += boot" trick for all architectures. This can take advantage of the parallel option (-j) for "make clean". I also cleaned up the comments in arch/$(SRCARCH)/Makefile. The "archdep" target no longer exists. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
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a757ac55 |
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28-Oct-2021 |
Elyes HAOUAS <ehaouas@noos.fr> |
x86/Makefile: Remove unneeded whitespaces before tabs Align the FDINITRD line to the FDARGS one with tabs. [ bp: Commit message. ] Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20211028121021.10384-1-ehaouas@noos.fr
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d8285639 |
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24-Jul-2021 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: do not require sub-make for separate output tree builds As explained in commit 3204a7fb98a3 ("kbuild: prefix $(srctree)/ to some included Makefiles"), I want to stop using --include-dir some day. I already fixed up the top Makefile, but some arch Makefiles (mips, um, x86) still include check-in Makefiles without $(srctree)/. Fix them up so 'need-sub-make := 1' can go away for this case. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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08155126 |
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29-Jul-2021 |
Masahiro Yamada <masahiroy@kernel.org> |
x86/build: Move the install rule to arch/x86/Makefile Currently, the install target in arch/x86/Makefile descends into arch/x86/boot/Makefile to invoke the shell script, but there is no good reason to do so. arch/x86/Makefile can run the shell script directly. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210729140023.442101-2-masahiroy@kernel.org
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6d61b8e6 |
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29-Jul-2021 |
Masahiro Yamada <masahiroy@kernel.org> |
x86/build: Remove the left-over bzlilo target Commit f279b49f13bd ("x86/boot: Modernize genimage script; hdimage+EFI support") removed the bzlilo target from arch/x86/boot/Makefile. Remove the left-over from arch/x86/Makefile. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210729140023.442101-1-masahiroy@kernel.org
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989ceac7 |
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12-Aug-2021 |
Nick Desaulniers <ndesaulniers@google.com> |
x86/build: Remove stale cc-option checks cc-option, __cc-option, cc-option-yn, and cc-disable-warning all invoke the compiler during build time, and can slow down the build when these checks become stale for our supported compilers, whose minimally supported versions increases over time. See Documentation/process/changes.rst for the current supported minimal versions (GCC 4.9+, clang 10.0.1+). Compiler version support for these flags may be verified on godbolt.org. The following flags are supported by all supported versions of GCC and Clang. Remove their cc-option, __cc-option, and cc-option-yn tests. -Wno-address-of-packed-member -mno-avx -m32 -mno-80387 -march=k8 -march=nocona -march=core2 -march=atom -mtune=generic -mfentry [ mingo: Fixed regression on GCC, via partial revert of the stack-boundary changes. ] Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://github.com/ClangBuiltLinux/linux/issues/1436 Link: https://lkml.kernel.org/r/20210812183848.1519994-1-ndesaulniers@google.com
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d92cc4d5 |
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12-May-2021 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: require all architectures to have arch/$(SRCARCH)/Kbuild arch/$(SRCARCH)/Kbuild is useful for Makefile cleanups because you can use the obj-y syntax. Add an empty file if it is missing in arch/$(SRCARCH)/. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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f279b49f |
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10-May-2021 |
H. Peter Anvin (Intel) <hpa@zytor.com> |
x86/boot: Modernize genimage script; hdimage+EFI support The image generation scripts in arch/x86/boot are pretty out of date, except for the isoimage target. Update and clean up the genimage.sh script, and make it support an arbitrary number of initramfs files in the image. Add a "hdimage" target, which can be booted by either BIOS or EFI (if the kernel is compiled with the EFI stub.) For EFI to be able to pass the command line to the kernel, we need the EFI shell, but the firmware builtin EFI shell, if it even exists, is pretty much always the last resort boot option, so search for OVMF or EDK2 and explicitly include a copy of the EFI shell. To make this all work, use bash features in the script. Furthermore, this version of the script makes use of some mtools features, especially mpartition, that might not exist in very old version of mtools, but given all the other dependencies on this script this doesn't seem such a big deal. Finally, put a volume label ("LINUX_BOOT") on all generated images. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210510082840.628372-1-hpa@zytor.com
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2398ce80 |
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10-Jun-2021 |
Tor Vic <torvic9@mailbox.org> |
x86, lto: Pass -stack-alignment only on LLD < 13.0.0 Since LLVM commit 3787ee4, the '-stack-alignment' flag has been dropped [1], leading to the following error message when building a LTO kernel with Clang-13 and LLD-13: ld.lld: error: -plugin-opt=-: ld.lld: Unknown command line argument '-stack-alignment=8'. Try 'ld.lld --help' ld.lld: Did you mean '--stackrealign=8'? It also appears that the '-code-model' flag is not necessary anymore starting with LLVM-9 [2]. Drop '-code-model' and make '-stack-alignment' conditional on LLD < 13.0.0. These flags were necessary because these flags were not encoded in the IR properly, so the link would restart optimizations without them. Now there are properly encoded in the IR, and these flags exposing implementation details are no longer necessary. [1] https://reviews.llvm.org/D103048 [2] https://reviews.llvm.org/D52322 Cc: stable@vger.kernel.org Link: https://github.com/ClangBuiltLinux/linux/issues/1377 Signed-off-by: Tor Vic <torvic9@mailbox.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/f2c018ee-5999-741e-58d4-e482d5246067@mailbox.org
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0024430e |
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18-May-2021 |
Nathan Chancellor <nathan@kernel.org> |
x86/build: Fix location of '-plugin-opt=' flags Commit b33fff07e3e3 ("x86, build: allow LTO to be selected") added a couple of '-plugin-opt=' flags to KBUILD_LDFLAGS because the code model and stack alignment are not stored in LLVM bitcode. However, these flags were added to KBUILD_LDFLAGS prior to the emulation flag assignment, which uses ':=', so they were overwritten and never added to $(LD) invocations. The absence of these flags caused misalignment issues in the AMDGPU driver when compiling with CONFIG_LTO_CLANG, resulting in general protection faults. Shuffle the assignment below the initial one so that the flags are properly passed along and all of the linker flags stay together. At the same time, avoid any future issues with clobbering flags by changing the emulation flag assignment to '+=' since KBUILD_LDFLAGS is already defined with ':=' in the main Makefile before being exported for modification here as a result of commit: ce99d0bf312d ("kbuild: clear LDFLAGS in the top Makefile") Fixes: b33fff07e3e3 ("x86, build: allow LTO to be selected") Reported-by: Anthony Ruhier <aruhier@mailbox.org> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Anthony Ruhier <aruhier@mailbox.org> Cc: stable@vger.kernel.org Link: https://github.com/ClangBuiltLinux/linux/issues/1374 Link: https://lore.kernel.org/r/20210518190106.60935-1-nathan@kernel.org
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e3456056 |
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15-Apr-2021 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: remove TMPO from try-run TMPO is only used by arch/x86/Makefile. Change arch/x86/Makefile to use $$TMPO.o and remove TMPO from scripts/Makefile.compiler. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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3fb0fdb3 |
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13-Feb-2021 |
Andy Lutomirski <luto@kernel.org> |
x86/stackprotector/32: Make the canary into a regular percpu variable On 32-bit kernels, the stackprotector canary is quite nasty -- it is stored at %gs:(20), which is nasty because 32-bit kernels use %fs for percpu storage. It's even nastier because it means that whether %gs contains userspace state or kernel state while running kernel code depends on whether stackprotector is enabled (this is CONFIG_X86_32_LAZY_GS), and this setting radically changes the way that segment selectors work. Supporting both variants is a maintenance and testing mess. Merely rearranging so that percpu and the stack canary share the same segment would be messy as the 32-bit percpu address layout isn't currently compatible with putting a variable at a fixed offset. Fortunately, GCC 8.1 added options that allow the stack canary to be accessed as %fs:__stack_chk_guard, effectively turning it into an ordinary percpu variable. This lets us get rid of all of the code to manage the stack canary GDT descriptor and the CONFIG_X86_32_LAZY_GS mess. (That name is special. We could use any symbol we want for the %fs-relative mode, but for CONFIG_SMP=n, gcc refuses to let us use any name other than __stack_chk_guard.) Forcibly disable stackprotector on older compilers that don't support the new options and turn the stack canary into a percpu variable. The "lazy GS" approach is now used for all 32-bit configurations. Also makes load_gs_index() work on 32-bit kernels. On 64-bit kernels, it loads the GS selector and updates the user GSBASE accordingly. (This is unchanged.) On 32-bit kernels, it loads the GS selector and updates GSBASE, which is now always the user base. This means that the overall effect is the same on 32-bit and 64-bit, which avoids some ifdeffery. [ bp: Massage commit message. ] Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/c0ff7dba14041c7e5d1cae5d4df052f03759bef3.1613243844.git.luto@kernel.org
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8abe7fc2 |
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25-Mar-2021 |
John Millikin <john@john-millikin.com> |
x86/build: Propagate $(CLANG_FLAGS) to $(REALMODE_FLAGS) When cross-compiling with Clang, the `$(CLANG_FLAGS)' variable contains additional flags needed to build C and assembly sources for the target platform. Normally this variable is automatically included in `$(KBUILD_CFLAGS)' via the top-level Makefile. The x86 real-mode makefile builds `$(REALMODE_CFLAGS)' from a plain assignment and therefore drops the Clang flags. This causes Clang to not recognize x86-specific assembler directives: arch/x86/realmode/rm/header.S:36:1: error: unknown directive .type real_mode_header STT_OBJECT ; .size real_mode_header, .-real_mode_header ^ Explicit propagation of `$(CLANG_FLAGS)' to `$(REALMODE_CFLAGS)', which is inherited by real-mode make rules, fixes cross-compilation with Clang for x86 targets. Relevant flags: * `--target' sets the target architecture when cross-compiling. This flag must be set for both compilation and assembly (`KBUILD_AFLAGS') to support architecture-specific assembler directives. * `-no-integrated-as' tells clang to assemble with GNU Assembler instead of its built-in LLVM assembler. This flag is set by default unless `LLVM_IAS=1' is set, because the LLVM assembler can't yet parse certain GNU extensions. Signed-off-by: John Millikin <john@john-millikin.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Link: https://lkml.kernel.org/r/20210326000435.4785-2-nathan@kernel.org
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9fcb51c1 |
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23-Mar-2021 |
Arnd Bergmann <arnd@arndb.de> |
x86/build: Turn off -fcf-protection for realmode targets The new Ubuntu GCC packages turn on -fcf-protection globally, which causes a build failure in the x86 realmode code: cc1: error: ‘-fcf-protection’ is not compatible with this target Turn it off explicitly on compilers that understand this option. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210323124846.1584944-1-arnd@kernel.org
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b33fff07 |
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10-Apr-2019 |
Sami Tolvanen <samitolvanen@google.com> |
x86, build: allow LTO to be selected Pass code model and stack alignment to the linker as these are not stored in LLVM bitcode, and allow CONFIG_LTO_CLANG* to be enabled. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org>
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a6a0683b |
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14-Jan-2021 |
Viresh Kumar <viresh.kumar@linaro.org> |
arch: x86: Remove CONFIG_OPROFILE support The "oprofile" user-space tools don't use the kernel OPROFILE support any more, and haven't in a long time. User-space has been converted to the perf interfaces. Remove the old oprofile's architecture specific support. Suggested-by: Christoph Hellwig <hch@infradead.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Robert Richter <rric@kernel.org> Acked-by: William Cohen <wcohen@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Thomas Gleixner <tglx@linutronix.de>
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ac5d0887 |
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17-Dec-2020 |
Borislav Petkov <bp@suse.de> |
x86/build: Realign archhelp Realign help text vertically and add spacing so that the target help text is properly separated. No functional changes. Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20201217134608.31811-2-bp@alien8.de
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fbaf0aa8 |
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17-Dec-2020 |
Borislav Petkov <bp@suse.de> |
x86/build: Add {kvm_guest,xen}.config targets to make help's output Add the targets which add additional items to the .config which facilitate running the kernel as a guest, to the 'make help' output so that they can be found easier and there's no need to grep the tree each time to remember what they should be called. Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20201217134608.31811-1-bp@alien8.de
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256b92af |
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08-Feb-2021 |
Borislav Petkov <bp@suse.de> |
x86/build: Disable CET instrumentation in the kernel for 32-bit too Commit 20bf2b378729 ("x86/build: Disable CET instrumentation in the kernel") disabled CET instrumentation which gets added by default by the Ubuntu gcc9 and 10 by default, but did that only for 64-bit builds. It would still fail when building a 32-bit target. So disable CET for all x86 builds. Fixes: 20bf2b378729 ("x86/build: Disable CET instrumentation in the kernel") Reported-by: AC <achirvasub@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested-by: AC <achirvasub@gmail.com> Link: https://lkml.kernel.org/r/YCCIgMHkzh/xT4ex@arch-chirva.localdomain
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20bf2b37 |
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28-Jan-2021 |
Josh Poimboeuf <jpoimboe@redhat.com> |
x86/build: Disable CET instrumentation in the kernel With retpolines disabled, some configurations of GCC, and specifically the GCC versions 9 and 10 in Ubuntu will add Intel CET instrumentation to the kernel by default. That breaks certain tracing scenarios by adding a superfluous ENDBR64 instruction before the fentry call, for functions which can be called indirectly. CET instrumentation isn't currently necessary in the kernel, as CET is only supported in user space. Disable it unconditionally and move it into the x86's Makefile as CET/CFI... enablement should be a per-arch decision anyway. [ bp: Massage and extend commit message. ] Fixes: 29be86d7f9cb ("kbuild: add -fcf-protection=none when using retpoline flags") Reported-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Tested-by: Nikolay Borisov <nborisov@suse.com> Cc: <stable@vger.kernel.org> Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Link: https://lkml.kernel.org/r/20210128215219.6kct3h2eiustncws@treble
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2838307b |
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30-Nov-2020 |
Nick Desaulniers <ndesaulniers@google.com> |
x86/build: Remove -m16 workaround for unsupported versions of GCC Revert the following two commits: de3accdaec88 ("x86, build: Build 16-bit code with -m16 where possible") a9cfccee6604 ("x86, build: Change code16gcc.h from a C header to an assembly header") Since 0bddd227f3dc ("Documentation: update for gcc 4.9 requirement") the minimum supported version of GCC is gcc-4.9. It's now safe to remove this code. Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> Link: https://lkml.kernel.org/r/20201201011307.3676986-1-ndesaulniers@google.com
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59612b24 |
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19-Nov-2020 |
Nathan Chancellor <nathan@kernel.org> |
kbuild: Hoist '--orphan-handling' into Kconfig Currently, '--orphan-handling=warn' is spread out across four different architectures in their respective Makefiles, which makes it a little unruly to deal with in case it needs to be disabled for a specific linker version (in this case, ld.lld 10.0.1). To make it easier to control this, hoist this warning into Kconfig and the main Makefile so that disabling it is simpler, as the warning will only be enabled in a couple places (main Makefile and a couple of compressed boot folders that blow away LDFLAGS_vmlinx) and making it conditional is easier due to Kconfig syntax. One small additional benefit of this is saving a call to ld-option on incremental builds because we will have already evaluated it for CONFIG_LD_ORPHAN_WARN. To keep the list of supported architectures the same, introduce CONFIG_ARCH_WANT_LD_ORPHAN_WARN, which an architecture can select to gain this automatically after all of the sections are specified and size asserted. A special thanks to Kees Cook for the help text on this config. Link: https://github.com/ClangBuiltLinux/linux/issues/1187 Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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83109d5d |
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01-Sep-2020 |
Kees Cook <keescook@chromium.org> |
x86/build: Warn on orphan section placement We don't want to depend on the linker's orphan section placement heuristics as these can vary between linkers, and may change between versions. All sections need to be explicitly handled in the linker script. Now that all sections are explicitly handled, enable orphan section warnings. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20200902025347.2504702-5-keescook@chromium.org
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587af649 |
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22-Jul-2020 |
Arvind Sankar <nivedita@alum.mit.edu> |
x86/build: Move max-page-size option to LDFLAGS_vmlinux This option is only required for vmlinux on 64-bit, to enforce 2MiB alignment, so set it in LDFLAGS_vmlinux instead of KBUILD_LDFLAGS. Also drop the ld-option check: this option was added in binutils-2.18 and all the other places that use it already don't have the check. This reduces the size of the intermediate ELF files arch/x86/boot/setup.elf and arch/x86/realmode/rm/realmode.elf by about 2MiB each. The binary versions are unchanged. Move the LDFLAGS settings to all be together and just after CFLAGS settings are done. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Marek <michal.lkml@markovi.net> Link: https://lore.kernel.org/r/20200722184334.3785418-1-nivedita@alum.mit.edu
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685969e0 |
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26-Jun-2020 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: remove cc-option test of -ffreestanding Some Makefiles already pass -ffreestanding unconditionally. For example, arch/arm64/lib/Makefile, arch/x86/purgatory/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -ffreestanding. I confirmed GCC 4.8 and Clang manuals document this option. Get rid of cc-option from -ffreestanding. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org>
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893ab004 |
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26-Jun-2020 |
Masahiro Yamada <masahiroy@kernel.org> |
kbuild: remove cc-option test of -fno-stack-protector Some Makefiles already pass -fno-stack-protector unconditionally. For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -fno-stack-protector. GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN) Get rid of cc-option from -fno-stack-protector. Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'. Note: arch/mips/vdso/Makefile adds -fno-stack-protector twice, first unconditionally, and second conditionally. I removed the second one. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
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30ce434e |
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14-Feb-2020 |
Masahiro Yamada <masahiroy@kernel.org> |
x86/boot/build: Make 'make bzlilo' not depend on vmlinux or $(obj)/bzImage bzlilo is an installation target because it copies files to $(INSTALL_PATH)/, then runs 'lilo'. However, arch/x86/Makefile and arch/x86/boot/Makefile have it depend on vmlinux and $(obj)/bzImage, respectively. 'make bzlilo' may update some build artifacts in the source tree. As commit 19514fc665ff ("arm, kbuild: make "make install" not depend on vmlinux") explained, this should not happen. Make 'bzlilo' not depend on any build artifact. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200215063852.8298-1-masahiroy@kernel.org
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5e8ebd84 |
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26-Mar-2020 |
Jason A. Donenfeld <Jason@zx2c4.com> |
x86: probe assembler capabilities via kconfig instead of makefile Doing this probing inside of the Makefiles means we have a maze of ifdefs inside the source code and child Makefiles that need to make proper decisions on this too. Instead, we do it at Kconfig time, like many other compiler and assembler options, which allows us to set up the dependencies normally for full compilation units. In the process, the ADX test changes to use %eax instead of %r10 so that it's valid in both 32-bit and 64-bit mode. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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42251572 |
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26-Mar-2020 |
Masahiro Yamada <masahiroy@kernel.org> |
x86: remove always-defined CONFIG_AS_AVX CONFIG_AS_AVX was introduced by commit ea4d26ae24e5 ("raid5: add AVX optimized RAID5 checksumming"). We raise the minimal supported binutils version from time to time. The last bump was commit 1fb12b35e5ff ("kbuild: Raise the minimum required binutils version to 2.21"). I confirmed the code in $(call as-instr,...) can be assembled by the binutils 2.21 assembler and also by LLVM integrated assembler. Remove CONFIG_AS_AVX, which is always defined. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Ingo Molnar <mingo@kernel.org>
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92203b02 |
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26-Mar-2020 |
Masahiro Yamada <masahiroy@kernel.org> |
x86: remove always-defined CONFIG_AS_SSSE3 CONFIG_AS_SSSE3 was introduced by commit 75aaf4c3e6a4 ("x86/raid6: correctly check for assembler capabilities"). We raise the minimal supported binutils version from time to time. The last bump was commit 1fb12b35e5ff ("kbuild: Raise the minimum required binutils version to 2.21"). I confirmed the code in $(call as-instr,...) can be assembled by the binutils 2.21 assembler and also by LLVM integrated assembler. Remove CONFIG_AS_SSSE3, which is always defined. I added ifdef CONFIG_X86 to lib/raid6/algos.c to avoid link errors on non-x86 architectures. lib/raid6/algos.c is built not only for the kernel but also for testing the library code from userspace. I added -DCONFIG_X86 to lib/raid6/test/Makefile to cator to this usecase. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Ingo Molnar <mingo@kernel.org>
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48e24723 |
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26-Mar-2020 |
Masahiro Yamada <masahiroy@kernel.org> |
x86: remove always-defined CONFIG_AS_CFI_SECTIONS CONFIG_AS_CFI_SECTIONS was introduced by commit 9e565292270a ("x86: Use .cfi_sections for assembly code"). We raise the minimal supported binutils version from time to time. The last bump was commit 1fb12b35e5ff ("kbuild: Raise the minimum required binutils version to 2.21"). I confirmed the code in $(call as-instr,...) can be assembled by the binutils 2.21 assembler and also by LLVM integrated assembler. Remove CONFIG_AS_CFI_SECTIONS, which is always defined. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Ingo Molnar <mingo@kernel.org>
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46427f65 |
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26-Mar-2020 |
Masahiro Yamada <masahiroy@kernel.org> |
x86: remove unneeded (CONFIG_AS_)CFI_SIGNAL_FRAME Commit 131484c8da97 ("x86/debug: Remove perpetually broken, unmaintainable dwarf annotations") removes all the users of CFI_SIGNAL_FRAME. Remove the CFI_SIGNAL_FRAME and CONFIG_AS_CFI_SIGNAL_FRAME. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Ingo Molnar <mingo@kernel.org>
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0f2661c4 |
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26-Mar-2020 |
Masahiro Yamada <masahiroy@kernel.org> |
x86: remove always-defined CONFIG_AS_CFI CONFIG_AS_CFI was introduced by commit e2414910f212 ("[PATCH] x86: Detect CFI support in the assembler at runtime"), and extended by commit f0f12d85af85 ("x86_64: Check for .cfi_rel_offset in CFI probe"). We raise the minimal supported binutils version from time to time. The last bump was commit 1fb12b35e5ff ("kbuild: Raise the minimum required binutils version to 2.21"). I confirmed the code in $(call as-instr,...) can be assembled by the binutils 2.21 assembler and also by LLVM integrated assembler. Remove CONFIG_AS_CFI, which is always defined. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Acked-by: Ingo Molnar <mingo@kernel.org>
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1579f1bc |
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01-Mar-2020 |
Jason A. Donenfeld <Jason@zx2c4.com> |
crypto: x86/curve25519 - support assemblers with no adx support Some older version of GAS do not support the ADX instructions, similarly to how they also don't support AVX and such. This commit adds the same build-time detection mechanisms we use for AVX and others for ADX, and then makes sure that the curve25519 library dispatcher calls the right functions. Reported-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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42e0e954 |
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28-Aug-2019 |
Linus Torvalds <torvalds@linux-foundation.org> |
x86/build: Add -Wnoaddress-of-packed-member to REALMODE_CFLAGS, to silence GCC9 build warning One of the very few warnings I have in the current build comes from arch/x86/boot/edd.c, where I get the following with a gcc9 build: arch/x86/boot/edd.c: In function ‘query_edd’: arch/x86/boot/edd.c:148:11: warning: taking address of packed member of ‘struct boot_params’ may result in an unaligned pointer value [-Waddress-of-packed-member] 148 | mbrptr = boot_params.edd_mbr_sig_buffer; | ^~~~~~~~~~~ This warning triggers because we throw away all the CFLAGS and then make a new set for REALMODE_CFLAGS, so the -Wno-address-of-packed-member we added in the following commit is not present: 6f303d60534c ("gcc-9: silence 'address-of-packed-member' warning") The simplest solution for now is to adjust the warning for this version of CFLAGS as well, but it would definitely make sense to examine whether REALMODE_CFLAGS could be derived from CFLAGS, so that it picks up changes in the compiler flags environment automatically. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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7c21383f |
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04-Apr-2019 |
Kees Cook <keescook@chromium.org> |
x86/build: Keep local relocations with ld.lld The LLVM linker (ld.lld) defaults to removing local relocations, which causes KASLR boot failures. ld.bfd and ld.gold already handle this correctly. This adds the explicit instruction "--discard-none" during the link phase. There is no change in output for ld.bfd and ld.gold, but ld.lld now produces an image with all the needed relocations. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: clang-built-linux@googlegroups.com Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/20190404214027.GA7324@beast Link: https://github.com/ClangBuiltLinux/linux/issues/404
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a9d57ef1 |
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25-Mar-2019 |
Daniel Borkmann <daniel@iogearbox.net> |
x86/retpolines: Disable switch jump tables when retpolines are enabled Commit ce02ef06fcf7 ("x86, retpolines: Raise limit for generating indirect calls from switch-case") raised the limit under retpolines to 20 switch cases where gcc would only then start to emit jump tables, and therefore effectively disabling the emission of slow indirect calls in this area. After this has been brought to attention to gcc folks [0], Martin Liska has then fixed gcc to align with clang by avoiding to generate switch jump tables entirely under retpolines. This is taking effect in gcc starting from stable version 8.4.0. Given kernel supports compilation with older versions of gcc where the fix is not being available or backported anymore, we need to keep the extra KBUILD_CFLAGS around for some time and generally set the -fno-jump-tables to align with what more recent gcc is doing automatically today. More than 20 switch cases are not expected to be fast-path critical, but it would still be good to align with gcc behavior for versions < 8.4.0 in order to have consistency across supported gcc versions. vmlinux size is slightly growing by 0.27% for older gcc. This flag is only set to work around affected gcc, no change for clang. [0] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86952 Suggested-by: Martin Liska <mliska@suse.cz> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Björn Töpel<bjorn.topel@intel.com> Cc: Magnus Karlsson <magnus.karlsson@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: David S. Miller <davem@davemloft.net> Link: https://lkml.kernel.org/r/20190325135620.14882-1-daniel@iogearbox.net
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ce02ef06 |
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21-Feb-2019 |
Daniel Borkmann <daniel@iogearbox.net> |
x86, retpolines: Raise limit for generating indirect calls from switch-case From networking side, there are numerous attempts to get rid of indirect calls in fast-path wherever feasible in order to avoid the cost of retpolines, for example, just to name a few: * 283c16a2dfd3 ("indirect call wrappers: helpers to speed-up indirect calls of builtin") * aaa5d90b395a ("net: use indirect call wrappers at GRO network layer") * 028e0a476684 ("net: use indirect call wrappers at GRO transport layer") * 356da6d0cde3 ("dma-mapping: bypass indirect calls for dma-direct") * 09772d92cd5a ("bpf: avoid retpoline for lookup/update/delete calls on maps") * 10870dd89e95 ("netfilter: nf_tables: add direct calls for all builtin expressions") [...] Recent work on XDP from Björn and Magnus additionally found that manually transforming the XDP return code switch statement with more than 5 cases into if-else combination would result in a considerable speedup in XDP layer due to avoidance of indirect calls in CONFIG_RETPOLINE enabled builds. On i40e driver with XDP prog attached, a 20-26% speedup has been observed [0]. Aside from XDP, there are many other places later in the networking stack's critical path with similar switch-case processing. Rather than fixing every XDP-enabled driver and locations in stack by hand, it would be good to instead raise the limit where gcc would emit expensive indirect calls from the switch under retpolines and stick with the default as-is in case of !retpoline configured kernels. This would also have the advantage that for archs where this is not necessary, we let compiler select the underlying target optimization for these constructs and avoid potential slow-downs by if-else hand-rewrite. In case of gcc, this setting is controlled by case-values-threshold which has an architecture global default that selects 4 or 5 (latter if target does not have a case insn that compares the bounds) where some arch back ends like arm64 or s390 override it with their own target hooks, for example, in gcc commit db7a90aa0de5 ("S/390: Disable prediction of indirect branches") the threshold pretty much disables jump tables by limit of 20 under retpoline builds. Comparing gcc's and clang's default code generation on x86-64 under O2 level with retpoline build results in the following outcome for 5 switch cases: * gcc with -mindirect-branch=thunk-inline -mindirect-branch-register: # gdb -batch -ex 'disassemble dispatch' ./c-switch Dump of assembler code for function dispatch: 0x0000000000400be0 <+0>: cmp $0x4,%edi 0x0000000000400be3 <+3>: ja 0x400c35 <dispatch+85> 0x0000000000400be5 <+5>: lea 0x915f8(%rip),%rdx # 0x4921e4 0x0000000000400bec <+12>: mov %edi,%edi 0x0000000000400bee <+14>: movslq (%rdx,%rdi,4),%rax 0x0000000000400bf2 <+18>: add %rdx,%rax 0x0000000000400bf5 <+21>: callq 0x400c01 <dispatch+33> 0x0000000000400bfa <+26>: pause 0x0000000000400bfc <+28>: lfence 0x0000000000400bff <+31>: jmp 0x400bfa <dispatch+26> 0x0000000000400c01 <+33>: mov %rax,(%rsp) 0x0000000000400c05 <+37>: retq 0x0000000000400c06 <+38>: nopw %cs:0x0(%rax,%rax,1) 0x0000000000400c10 <+48>: jmpq 0x400c90 <fn_3> 0x0000000000400c15 <+53>: nopl (%rax) 0x0000000000400c18 <+56>: jmpq 0x400c70 <fn_2> 0x0000000000400c1d <+61>: nopl (%rax) 0x0000000000400c20 <+64>: jmpq 0x400c50 <fn_1> 0x0000000000400c25 <+69>: nopl (%rax) 0x0000000000400c28 <+72>: jmpq 0x400c40 <fn_0> 0x0000000000400c2d <+77>: nopl (%rax) 0x0000000000400c30 <+80>: jmpq 0x400cb0 <fn_4> 0x0000000000400c35 <+85>: push %rax 0x0000000000400c36 <+86>: callq 0x40dd80 <abort> End of assembler dump. * clang with -mretpoline emitting search tree: # gdb -batch -ex 'disassemble dispatch' ./c-switch Dump of assembler code for function dispatch: 0x0000000000400b30 <+0>: cmp $0x1,%edi 0x0000000000400b33 <+3>: jle 0x400b44 <dispatch+20> 0x0000000000400b35 <+5>: cmp $0x2,%edi 0x0000000000400b38 <+8>: je 0x400b4d <dispatch+29> 0x0000000000400b3a <+10>: cmp $0x3,%edi 0x0000000000400b3d <+13>: jne 0x400b52 <dispatch+34> 0x0000000000400b3f <+15>: jmpq 0x400c50 <fn_3> 0x0000000000400b44 <+20>: test %edi,%edi 0x0000000000400b46 <+22>: jne 0x400b5c <dispatch+44> 0x0000000000400b48 <+24>: jmpq 0x400c20 <fn_0> 0x0000000000400b4d <+29>: jmpq 0x400c40 <fn_2> 0x0000000000400b52 <+34>: cmp $0x4,%edi 0x0000000000400b55 <+37>: jne 0x400b66 <dispatch+54> 0x0000000000400b57 <+39>: jmpq 0x400c60 <fn_4> 0x0000000000400b5c <+44>: cmp $0x1,%edi 0x0000000000400b5f <+47>: jne 0x400b66 <dispatch+54> 0x0000000000400b61 <+49>: jmpq 0x400c30 <fn_1> 0x0000000000400b66 <+54>: push %rax 0x0000000000400b67 <+55>: callq 0x40dd20 <abort> End of assembler dump. For sake of comparison, clang without -mretpoline: # gdb -batch -ex 'disassemble dispatch' ./c-switch Dump of assembler code for function dispatch: 0x0000000000400b30 <+0>: cmp $0x4,%edi 0x0000000000400b33 <+3>: ja 0x400b57 <dispatch+39> 0x0000000000400b35 <+5>: mov %edi,%eax 0x0000000000400b37 <+7>: jmpq *0x492148(,%rax,8) 0x0000000000400b3e <+14>: jmpq 0x400bf0 <fn_0> 0x0000000000400b43 <+19>: jmpq 0x400c30 <fn_4> 0x0000000000400b48 <+24>: jmpq 0x400c10 <fn_2> 0x0000000000400b4d <+29>: jmpq 0x400c20 <fn_3> 0x0000000000400b52 <+34>: jmpq 0x400c00 <fn_1> 0x0000000000400b57 <+39>: push %rax 0x0000000000400b58 <+40>: callq 0x40dcf0 <abort> End of assembler dump. Raising the cases to a high number (e.g. 100) will still result in similar code generation pattern with clang and gcc as above, in other words clang generally turns off jump table emission by having an extra expansion pass under retpoline build to turn indirectbr instructions from their IR into switch instructions as a built-in -mno-jump-table lowering of a switch (in this case, even if IR input already contained an indirect branch). For gcc, adding --param=case-values-threshold=20 as in similar fashion as s390 in order to raise the limit for x86 retpoline enabled builds results in a small vmlinux size increase of only 0.13% (before=18,027,528 after=18,051,192). For clang this option is ignored due to i) not being needed as mentioned and ii) not having above cmdline parameter. Non-retpoline-enabled builds with gcc continue to use the default case-values-threshold setting, so nothing changes here. [0] https://lore.kernel.org/netdev/20190129095754.9390-1-bjorn.topel@gmail.com/ and "The Path to DPDK Speeds for AF_XDP", LPC 2018, networking track: - http://vger.kernel.org/lpc_net2018_talks/lpc18_pres_af_xdp_perf-v3.pdf - http://vger.kernel.org/lpc_net2018_talks/lpc18_paper_af_xdp_perf-v2.pdf Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: netdev@vger.kernel.org Cc: David S. Miller <davem@davemloft.net> Cc: Magnus Karlsson <magnus.karlsson@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Link: https://lkml.kernel.org/r/20190221221941.29358-1-daniel@iogearbox.net
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bae54dc4 |
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17-Jan-2019 |
Borislav Petkov <bp@suse.de> |
x86/fpu: Get rid of CONFIG_AS_FXSAVEQ This was a "workaround" to probe for binutils which could generate FXSAVEQ, apparently gas with min version 2.16. In the meantime, minimal required gas version is 2.20 so all those workarounds for older binutils can be dropped. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20190117232408.GH5023@zn.tnic
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e9666d10 |
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30-Dec-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
jump_label: move 'asm goto' support test to Kconfig Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
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6ac38934 |
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19-Dec-2018 |
Ingo Molnar <mingo@kernel.org> |
Revert "kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs" This reverts commit 77b0bf55bc675233d22cd5df97605d516d64525e. See this commit for details about the revert: e769742d3584 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"") Conflicts: arch/x86/Makefile Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Borislav Petkov <bp@alien8.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Juergen Gross <jgross@suse.com> Cc: Richard Biener <rguenther@suse.de> Cc: Kees Cook <keescook@chromium.org> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Nadav Amit <namit@vmware.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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63fea0af |
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11-Nov-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
x86, powerpc: Remove -funit-at-a-time compiler option entirely GCC 4.6 manual says: -funit-at-a-time This option is left for compatibility reasons. -funit-at-a-time has no effect, while -fno-unit-at-a-time implies -fno-toplevel-reorder and -fno-section-anchors. Enabled by default. Remove it. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Richard Weinberger <richard@sigma-star.at> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linuxppc-dev@lists.ozlabs.org Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/1541990120-9643-3-git-send-email-yamada.masahiro@socionext.com
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25896d07 |
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04-Dec-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
x86/build: Fix compiler support check for CONFIG_RETPOLINE It is troublesome to add a diagnostic like this to the Makefile parse stage because the top-level Makefile could be parsed with a stale include/config/auto.conf. Once you are hit by the error about non-retpoline compiler, the compilation still breaks even after disabling CONFIG_RETPOLINE. The easiest fix is to move this check to the "archprepare" like this commit did: 829fe4aa9ac1 ("x86: Allow generating user-space headers without a compiler") Reported-by: Meelis Roos <mroos@linux.ee> Tested-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com> Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support") Link: http://lkml.kernel.org/r/1543991239-18476-1-git-send-email-yamada.masahiro@socionext.com Link: https://lkml.org/lkml/2018/12/4/206 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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4cd24de3 |
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02-Nov-2018 |
Zhenzhong Duan <zhenzhong.duan@oracle.com> |
x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support Since retpoline capable compilers are widely available, make CONFIG_RETPOLINE hard depend on the compiler capability. Break the build when CONFIG_RETPOLINE is enabled and the compiler does not support it. Emit an error message in that case: "arch/x86/Makefile:226: *** You are building kernel with non-retpoline compiler, please update your compiler.. Stop." [dwmw: Fail the build with non-retpoline compiler] Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Borislav Petkov <bp@suse.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Marek <michal.lkml@markovi.net> Cc: <srinivas.eeda@oracle.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/cca0cb20-f9e2-4094-840b-fb0f8810cd34@default
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437e88ab |
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23-Oct-2018 |
Nathan Chancellor <nathan@kernel.org> |
x86/build: Remove -pipe from KBUILD_CFLAGS Commit 77b0bf55bc67 ("kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs") added -Wa,- to KBUILD_CFLAGS, which breaks compiling with Clang (hangs indefinitely at compiling init/main.o). This happens because while Clang accepts -pipe (and has it documented in its list of supported flags), it silently ignores it after this 2010 commit (thanks to Nick Desaulniers for tracking this down), meaning that gas just infinitely waits for stdin and never receives it. https://github.com/llvm-mirror/clang/commit/c19a12dc3d441bec62eed55e312b76c12d6d9022 Initially, I had suggested just add -Wa,- to KBUILD_CFLAGS when GCC was being used but that was before realizing it is because Clang doesn't do anything with -pipe. H. Peter Anvin suggested checking to see if -pipe gives us any gains out of GCC. Turns out it might actually be hurting: With -pipe: real 3m40.813s real 3m44.449s real 3m39.648s Without -pipe: real 3m38.492s real 3m38.335s real 3m38.975s The issue of -Wa,- being passed along to gas without -pipe being supported should still probably be fixed on the LLVM side (open issue: https://bugs.llvm.org/show_bug.cgi?id=39410) but this is not as much of a workaround anymore since it helps both GCC and Clang. Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nadav Amit <namit@vmware.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Kees Cook <keescook@chromium.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Link: https://github.com/ClangBuiltLinux/linux/issues/213 Link: https://lkml.kernel.org/r/20181023231125.27976-1-natechancellor@gmail.com
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77b0bf55 |
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03-Oct-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>
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ac0d6567 |
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01-Oct-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
x86/build: Remove unused CONFIG_AS_CRC32 CONFIG_AS_CRC32 is not used anywhere. Its last user was removed by 0cb6c969ed9d ("net, lib: kill arch_fast_hash library bits") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Link: https://lkml.kernel.org/r/1538389443-28514-1-git-send-email-yamada.masahiro@socionext.com
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829fe4aa |
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29-Aug-2018 |
Ben Hutchings <ben@decadent.org.uk> |
x86: Allow generating user-space headers without a compiler When bootstrapping an architecture, it's usual to generate the kernel's user-space headers (make headers_install) before building a compiler. Move the compiler check (for asm goto support) to the archprepare target so that it is only done when building code for the target. Fixes: e501ce957a78 ("x86: Force asm-goto") Reported-by: Helmut Grohne <helmutg@debian.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180829194317.GA4765@decadent.org.uk
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36bf9da2 |
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26-Aug-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
x86/build: Remove jump label quirk for GCC older than 4.5.2 Commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6") bumped the minimum GCC version to 4.6 for all architectures. Remove the workaround code. It was the only user of cc-if-fullversion. Remove the macro as well. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Michal Marek <michal.lkml@markovi.net> Cc: linux-kbuild@vger.kernel.org Link: https://lkml.kernel.org/r/1535348714-25457-1-git-send-email-yamada.masahiro@socionext.com
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d503ac53 |
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23-Aug-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
kbuild: rename LDFLAGS to KBUILD_LDFLAGS Commit a0f97e06a43c ("kbuild: enable 'make CFLAGS=...' to add additional options to CC") renamed CFLAGS to KBUILD_CFLAGS. Commit 222d394d30e7 ("kbuild: enable 'make AFLAGS=...' to add additional options to AS") renamed AFLAGS to KBUILD_AFLAGS. Commit 06c5040cdb13 ("kbuild: enable 'make CPPFLAGS=...' to add additional options to CPP") renamed CPPFLAGS to KBUILD_CPPFLAGS. For some reason, LDFLAGS was not renamed. Using a well-known variable like LDFLAGS may result in accidental override of the variable. Kbuild generally uses KBUILD_ prefixed variables for the internally appended options, so here is one more conversion to sanitize the naming convention. I did not touch Makefiles under tools/ since the tools build system is a different world. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
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bdc9c3e5 |
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09-Jul-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
x86/build: Remove old -funit-at-a-time GCC quirk The following commit: e501ce957a78 ("x86: Force asm-goto") ... bumped the minimum GCC version to 4.5 for building the x86 kernel. arch/x86/Makefile no longer needs to take care of older GCC versions, such as this pre-4.0 -funit-at-a-time quirk. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Link: http://lkml.kernel.org/r/1531138041-24200-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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d6605b6b |
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19-Jun-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
x86/build: Remove unnecessary preparation for purgatory kexec-purgatory.c is properly generated when Kbuild descend into the arch/x86/purgatory/. Thus the 'archprepare' target is redundant. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.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> Link: https://lore.kernel.org/lkml/1529401422-28838-3-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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bdab125c |
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19-Jun-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
Revert "kexec/purgatory: Add clean-up for purgatory directory" Reverts the following commit: b0108f9e93d0 ("kexec: purgatory: add clean-up for purgatory directory") ... which incorrectly stated that the kexec-purgatory.c and purgatory.ro files were not removed after 'make mrproper'. In fact, they are. You can confirm it after reverting it. $ make mrproper $ touch arch/x86/purgatory/kexec-purgatory.c $ touch arch/x86/purgatory/purgatory.ro $ make mrproper CLEAN arch/x86/purgatory $ ls arch/x86/purgatory/ entry64.S Makefile purgatory.c setup-x86_64.S stack.S string.c This is obvious from the build system point of view. arch/x86/Makefile adds 'arch/x86' to core-y. Hence 'make clean' descends like this: arch/x86/Kbuild -> arch/x86/purgatory/Makefile Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.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> Link: https://lore.kernel.org/lkml/1529401422-28838-2-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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1f2f01b1 |
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30-May-2018 |
Luc Van Oostenryck <luc.vanoostenryck@gmail.com> |
kbuild: add machine size to CHECKFLAGS By default, sparse assumes a 64bit machine when compiled on x86-64 and 32bit when compiled on anything else. This can of course create all sort of problems for the other archs, like issuing false warnings ('shift too big (32) for type unsigned long'), or worse, failing to emit legitimate warnings. Fix this by adding the -m32/-m64 flag, depending on CONFIG_64BIT, to CHECKFLAGS in the main Makefile (and so for all archs). Also, remove the now unneeded -m32/-m64 in arch specific Makefiles. Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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d6289f36 |
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16-Mar-2018 |
Cao jin <caoj.fnst@cn.fujitsu.com> |
x86/build: Don't pass in -D__KERNEL__ multiple times Some .<target>.cmd files under arch/x86 are showing two instances of -D__KERNEL__, like arch/x86/boot/ and arch/x86/realmode/rm/. __KERNEL__ is already defined in KBUILD_CPPFLAGS in the top Makefile, so it can be dropped safely. Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kbuild@vger.kernel.org Link: http://lkml.kernel.org/r/20180316084944.3997-1-caoj.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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e501ce95 |
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17-Jan-2018 |
Peter Zijlstra <peterz@infradead.org> |
x86: Force asm-goto We want to start using asm-goto to guarantee the absence of dynamic branches (and thus speculation). A primary prerequisite for this is of course that the compiler supports asm-goto. This effecively lifts the minimum GCC version to build an x86 kernel to gcc-4.5. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: torvalds@linux-foundation.org Link: https://lkml.kernel.org/r/20180319201327.GJ4043@hirez.programming.kicks-ass.net
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e3d03598 |
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19-Mar-2018 |
H.J. Lu <hjl.tools@gmail.com> |
x86/build/64: Force the linker to use 2MB page size Binutils 2.31 will enable -z separate-code by default for x86 to avoid mixing code pages with data to improve cache performance as well as security. To reduce x86-64 executable and shared object sizes, the maximum page size is reduced from 2MB to 4KB. But x86-64 kernel must be aligned to 2MB. Pass -z max-page-size=0x200000 to linker to force 2MB page size regardless of the default page size used by linker. Tested with Linux kernel 4.15.6 on x86-64. Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/CAMe9rOp4_%3D_8twdpTyAP2DhONOCeaTOsniJLoppzhoNptL8xzA@mail.gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
d5028ba8 |
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06-Feb-2018 |
Peter Zijlstra <peterz@infradead.org> |
objtool, retpolines: Integrate objtool with retpoline support more closely Disable retpoline validation in objtool if your compiler sucks, and otherwise select the validation stuff for CONFIG_RETPOLINE=y (most builds would already have it set due to ORC). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
87358710 |
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19-Feb-2018 |
David Woodhouse <dwmw@amazon.co.uk> |
x86/retpoline: Support retpoline builds with Clang Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: arjan.van.de.ven@intel.com Cc: bp@alien8.de Cc: dave.hansen@intel.com Cc: jmattson@google.com Cc: karahmed@amazon.de Cc: kvm@vger.kernel.org Cc: pbonzini@redhat.com Cc: rkrcmar@redhat.com Link: http://lkml.kernel.org/r/1519037457-7643-5-git-send-email-dwmw@amazon.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
b8b9ce4b |
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14-Jan-2018 |
Thomas Gleixner <tglx@linutronix.de> |
x86/retpoline: Remove compile time warning Remove the compile time warning when CONFIG_RETPOLINE=y and the compiler does not have retpoline support. Linus rationale for this is: It's wrong because it will just make people turn off RETPOLINE, and the asm updates - and return stack clearing - that are independent of the compiler are likely the most important parts because they are likely the ones easiest to target. And it's annoying because most people won't be able to do anything about it. The number of people building their own compiler? Very small. So if their distro hasn't got a compiler yet (and pretty much nobody does), the warning is just annoying crap. It is already properly reported as part of the sysfs interface. The compile-time warning only encourages bad things. Fixes: 76b043848fd2 ("x86/retpoline: Add initial retpoline support") Requested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: thomas.lendacky@amd.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Link: https://lkml.kernel.org/r/CA+55aFzWgquv4i6Mab6bASqYXg3ErV3XDFEYf=GEcCDQg5uAtw@mail.gmail.com
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#
76b04384 |
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11-Jan-2018 |
David Woodhouse <dwmw@amazon.co.uk> |
x86/retpoline: Add initial retpoline support Enable the use of -mindirect-branch=thunk-extern in newer GCC, and provide the corresponding thunks. Provide assembler macros for invoking the thunks in the same way that GCC does, from native and inline assembler. This adds X86_FEATURE_RETPOLINE and sets it by default on all CPUs. In some circumstances, IBRS microcode features may be used instead, and the retpoline can be disabled. On AMD CPUs if lfence is serialising, the retpoline can be dramatically simplified to a simple "lfence; jmp *\reg". A future patch, after it has been verified that lfence really is serialising in all circumstances, can enable this by setting the X86_FEATURE_RETPOLINE_AMD feature bit in addition to X86_FEATURE_RETPOLINE. Do not align the retpoline in the altinstr section, because there is no guarantee that it stays aligned when it's copied over the oldinstr during alternative patching. [ Andi Kleen: Rename the macros, add CONFIG_RETPOLINE option, export thunks] [ tglx: Put actual function CALL/JMP in front of the macros, convert to symbolic labels ] [ dwmw2: Convert back to numeric labels, merge objtool fixes ] Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: thomas.lendacky@amd.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: https://lkml.kernel.org/r/1515707194-20531-4-git-send-email-dwmw@amazon.co.uk
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#
49502766 |
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15-Nov-2017 |
Levin, Alexander (Sasha Levin) <alexander.levin@verizon.com> |
kmemcheck: remove annotations Patch series "kmemcheck: kill kmemcheck", v2. As discussed at LSF/MM, kill kmemcheck. KASan is a replacement that is able to work without the limitation of kmemcheck (single CPU, slow). KASan is already upstream. We are also not aware of any users of kmemcheck (or users who don't consider KASan as a suitable replacement). The only objection was that since KASAN wasn't supported by all GCC versions provided by distros at that time we should hold off for 2 years, and try again. Now that 2 years have passed, and all distros provide gcc that supports KASAN, kill kmemcheck again for the very same reasons. This patch (of 4): Remove kmemcheck annotations, and calls to kmemcheck from the kernel. [alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs] Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.com Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Cc: Alexander Potapenko <glider@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tim Hansen <devtimhansen@gmail.com> Cc: Vegard Nossum <vegardno@ifi.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
b2441318 |
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01-Nov-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>
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#
9e8730b1 |
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17-Aug-2017 |
Matthias Kaehlcke <mka@chromium.org> |
x86/build: Use cc-option to validate stack alignment parameter With the following commit: 8f91869766c0 ("x86/build: Fix stack alignment for CLang") cc-option is only used to determine the name of the stack alignment option supported by the compiler, but not to verify that the actual parameter <option>=N is valid in combination with the other CFLAGS. This causes problems (as reported by the kbuild robot) with older GCC versions which only support stack alignment on a boundary of 16 bytes or higher. Also use (__)cc_option to add the stack alignment option to CFLAGS to make sure only valid options are added. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bernhard.Rosenkranzer@linaro.org Cc: Greg Hackmann <ghackmann@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michael Davidson <md@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hines <srhines@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dianders@chromium.org Fixes: 8f91869766c0 ("x86/build: Fix stack alignment for CLang") Link: http://lkml.kernel.org/r/20170817182047.176752-1-mka@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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8f918697 |
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16-Aug-2017 |
Matthias Kaehlcke <mka@chromium.org> |
x86/build: Fix stack alignment for CLang Commit: d77698df39a5 ("x86/build: Specify stack alignment for clang") intended to use the same stack alignment for clang as with gcc. The two compilers use different options to configure the stack alignment (gcc: -mpreferred-stack-boundary=n, clang: -mstack-alignment=n). The above commit assumes that the clang option uses the same parameter type as gcc, i.e. that the alignment is specified as 2^n. However clang interprets the value of this option literally to use an alignment of n, in consequence the stack remains misaligned. Change the values used with -mstack-alignment to be the actual alignment instead of a power of two. cc-option isn't used here with the typical pattern of KBUILD_CFLAGS += $(call cc-option ...). The reason is that older gcc versions don't support the -mpreferred-stack-boundary option, since cc-option doesn't verify whether the alternative option is valid it would incorrectly select the clang option -mstack-alignment.. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bernhard.Rosenkranzer@linaro.org Cc: Greg Hackmann <ghackmann@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michael Davidson <md@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hines <srhines@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dianders@chromium.org Link: http://lkml.kernel.org/r/20170817004740.170588-1-mka@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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e20f7e5e |
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07-Aug-2017 |
Cao jin <caoj.fnst@cn.fujitsu.com> |
x86/build: Drop unused mflags-y Subarchitecture support (mflags-y) was removed from x86 in this commit: 6bda2c8b32fe ("x86: remove subarchitecture support") So drop the mflags-y usage from the Makefile. Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1502105384-23214-1-git-send-email-caoj.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
d77698df |
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21-Jun-2017 |
Matthias Kaehlcke <mka@chromium.org> |
x86/build: Specify stack alignment for clang For gcc stack alignment is configured with -mpreferred-stack-boundary=N, clang has the option -mstack-alignment=N for that purpose. Use the same alignment as with gcc. If the alignment is not specified clang assumes an alignment of 16 bytes, as required by the standard ABI. However as mentioned in d9b0cde91c60 ("x86-64, gcc: Use -mpreferred-stack-boundary=3 if supported") the standard kernel entry on x86-64 leaves the stack on an 8-byte boundary, as a consequence clang will keep the stack misaligned. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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#
032a2c4f |
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21-Jun-2017 |
Matthias Kaehlcke <mka@chromium.org> |
x86/build: Use __cc-option for boot code compiler options cc-option is used to enable compiler options for the boot code if they are available. The macro uses KBUILD_CFLAGS and KBUILD_CPPFLAGS for the check, however these flags aren't used to build the boot code, in consequence cc-option can yield wrong results. For example -mpreferred-stack-boundary=2 is never set with a 64-bit compiler, since the setting is only valid for 16 and 32-bit binaries. This is also the case for 32-bit kernel builds, because the option -m32 is added to KBUILD_CFLAGS after the assignment of REALMODE_CFLAGS. Use __cc-option instead of cc-option for the boot mode options. The macro receives the compiler options as parameter instead of using KBUILD_C*FLAGS, for the boot code we pass REALMODE_CFLAGS. Also use separate statements for the __cc-option checks instead of performing them in the initial assignment of REALMODE_CFLAGS since the variable is an input of the macro. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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bc8e80d5 |
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13-Jun-2017 |
Borislav Petkov <bp@suse.de> |
x86/mce: Merge mce_amd_inj into mce-inject Reuse mce_amd_inj's debugfs interface so that mce-inject can benefit from it too. The old functionality is still preserved under CONFIG_X86_MCELOG_LEGACY. Tested-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Yazen Ghannam <yazen.ghannam@amd.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/20170613162835.30750-4-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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7e609120 |
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23-May-2017 |
Jan Kiszka <jan.kiszka@siemens.com> |
x86/build: Permit building with old make versions At least Make 3.82 dislikes the tab in front of the $(warning) function: arch/x86/Makefile:162: *** recipe commences before first target. Stop. Let's be gentle. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1944fcd8-e3df-d1f7-c0e4-60aeb1917a24@siemens.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
4a1bec46 |
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08-May-2017 |
Nick Desaulniers <nick.desaulniers@gmail.com> |
x86/build: Don't add -maccumulate-outgoing-args w/o compiler support Clang does not support this machine dependent option. Older versions of GCC (pre 3.0) may not support this option, added in 2000, but it's unlikely they can still compile a working kernel. Signed-off-by: Nick Desaulniers <nick.desaulniers@gmail.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170509032946.20444-1-nick.desaulniers@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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a5859c6d |
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18-Apr-2017 |
Josh Poimboeuf <jpoimboe@redhat.com> |
x86/build: convert function graph '-Os' error to warning For pre-4.6.0 versions of GCC, which don't have '-mfentry', the '-maccumulate-outgoing-args' option is required for function graph tracing in order to avoid GCC bug 42109. However, GCC ignores '-maccumulate-outgoing-args' when '-Os' is also set. Currently we force a build error to prevent that scenario, but that breaks randconfigs. So change the error to a warning which also disables CONFIG_CC_OPTIMIZE_FOR_SIZE. Reported-by: Andi Kleen <andi@firstfloor.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kbuild test robot <fengguang.wu@intel.com> Cc: kbuild-all@01.org Link: http://lkml.kernel.org/r/20170418214429.o7fbwbmf4nqosezy@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
2c4fd1ac |
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13-Apr-2017 |
Matthias Kaehlcke <mka@chromium.org> |
x86/kbuild: Use cc-option to enable -falign-{jumps/loops} clang currently does not support these optimizations, only enable them when they are available. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Cc: Greg Hackmann <ghackmann@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michael Davidson <md@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: grundler@chromium.org Link: http://lkml.kernel.org/r/20170413172609.118122-1-mka@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
3f135e57 |
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16-Mar-2017 |
Josh Poimboeuf <jpoimboe@redhat.com> |
x86/build: Mostly disable '-maccumulate-outgoing-args' The GCC '-maccumulate-outgoing-args' flag is enabled for most configs, mostly because of issues which are no longer relevant. For most configs, and with most recent versions of GCC, it's no longer needed. Clarify which cases need it, and only enable it for those cases. Also produce a compile-time error for the ftrace graph + mcount + '-Os' case, which will otherwise cause runtime failures. The main benefit of '-maccumulate-outgoing-args' is that it prevents an ugly prologue for functions which have aligned stacks. But removing the option also has some benefits: more readable argument saves, smaller text size, and (presumably) slightly improved performance. Here are the object size savings for 32-bit and 64-bit defconfig kernels: text data bss dec hex filename 10006710 3543328 1773568 15323606 e9d1d6 vmlinux.x86-32.before 9706358 3547424 1773568 15027350 e54c96 vmlinux.x86-32.after text data bss dec hex filename 10652105 4537576 843776 16033457 f4a6b1 vmlinux.x86-64.before 10639629 4537576 843776 16020981 f475f5 vmlinux.x86-64.after That comes out to a 3% text size improvement on x86-32 and a 0.1% text size improvement on x86-64. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Lutomirski <luto@kernel.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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170316193133.zrj6gug53766m6nn@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
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e0a491c1 |
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12-Aug-2016 |
Gayatri Kammela <gayatri.kammela@intel.com> |
lib/raid6: Add AVX512 optimized gen_syndrome functions Optimize RAID6 gen_syndrom functions to take advantage of the 512-bit ZMM integer instructions introduced in AVX512. AVX512 optimized gen_syndrom functions, which is simply based on avx2.c written by Yuanhan Liu and sse2.c written by hpa. The patch was tested and benchmarked before submission on a hardware that has AVX512 flags to support such instructions Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Megha Dey <megha.dey@linux.intel.com> Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Shaohua Li <shli@fb.com>
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c965b105 |
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26-Jul-2016 |
Kees Cook <keescook@chromium.org> |
kbuild: abort build on bad stack protector flag Before, the stack protector flag was sanity checked before .config had been reprocessed. This meant the build couldn't be aborted early, and only a warning could be emitted followed later by the compiler blowing up with an unknown flag. This has caused a lot of confusion over time, so this splits the flag selection from sanity checking and performs the sanity checking after the make has been restarted from a reprocessed .config, so builds can be aborted as early as possible now. Additionally moves the x86-specific sanity check to the same location, since it suffered from the same warn-then-wait-for-compiler-failure problem. Link: http://lkml.kernel.org/r/20160712223043.GA11664@www.outflux.net Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Michal Marek <mmarek@suse.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
228d96c6 |
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26-Jul-2016 |
Kees Cook <keescook@chromium.org> |
kbuild: Abort build on bad stack protector flag Before, the stack protector flag was sanity checked before .config had been reprocessed. This meant the build couldn't be aborted early, and only a warning could be emitted followed later by the compiler blowing up with an unknown flag. This has caused a lot of confusion over time, so this splits the flag selection from sanity checking and performs the sanity checking after the make has been restarted from a reprocessed .config, so builds can be aborted as early as possible now. Additionally moves the x86-specific sanity check to the same location, since it suffered from the same warn-then-wait-for-compiler-failure problem. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Michal Marek <mmarek@suse.com>
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#
f2d85299 |
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13-Apr-2016 |
Luis R. Rodriguez <mcgrof@kernel.org> |
x86/init: Rename EBDA code file This makes it clearer what this is. Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: andrew.cooper3@citrix.com Cc: andriy.shevchenko@linux.intel.com Cc: bigeasy@linutronix.de Cc: boris.ostrovsky@oracle.com Cc: david.vrabel@citrix.com Cc: ffainelli@freebox.fr Cc: george.dunlap@citrix.com Cc: glin@suse.com Cc: jgross@suse.com Cc: jlee@suse.com Cc: josh@joshtriplett.org Cc: julien.grall@linaro.org Cc: konrad.wilk@oracle.com Cc: kozerkov@parallels.com Cc: lenb@kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-acpi@vger.kernel.org Cc: lv.zheng@intel.com Cc: matt@codeblueprint.co.uk Cc: mbizon@freebox.fr Cc: rjw@rjwysocki.net Cc: robert.moore@intel.com Cc: rusty@rustcorp.com.au Cc: tiwai@suse.de Cc: toshi.kani@hp.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/1460592286-300-14-git-send-email-mcgrof@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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8d152e7a |
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13-Apr-2016 |
Luis R. Rodriguez <mcgrof@kernel.org> |
x86/rtc: Replace paravirt rtc check with platform legacy quirk We have 4 types of x86 platforms that disable RTC: * Intel MID * Lguest - uses paravirt * Xen dom-U - uses paravirt * x86 on legacy systems annotated with an ACPI legacy flag We can consolidate all of these into a platform specific legacy quirk set early in boot through i386_start_kernel() and through x86_64_start_reservations(). This deals with the RTC quirks which we can rely on through the hardware subarch, the ACPI check can be dealt with separately. For Xen things are bit more complex given that the @X86_SUBARCH_XEN x86_hardware_subarch is shared on for Xen which uses the PV path for both domU and dom0. Since the semantics for differentiating between the two are Xen specific we provide a platform helper to help override default legacy features -- x86_platform.set_legacy_features(). Use of this helper is highly discouraged, its only purpose should be to account for the lack of semantics available within your given x86_hardware_subarch. As per 0-day, this bumps the vmlinux size using i386-tinyconfig as follows: TOTAL TEXT init.text x86_early_init_platform_quirks() +70 +62 +62 +43 Only 8 bytes overhead total, as the main increase in size is all removed via __init. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Reviewed-by: Juergen Gross <jgross@suse.com> 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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: andrew.cooper3@citrix.com Cc: andriy.shevchenko@linux.intel.com Cc: bigeasy@linutronix.de Cc: boris.ostrovsky@oracle.com Cc: david.vrabel@citrix.com Cc: ffainelli@freebox.fr Cc: george.dunlap@citrix.com Cc: glin@suse.com Cc: jlee@suse.com Cc: josh@joshtriplett.org Cc: julien.grall@linaro.org Cc: konrad.wilk@oracle.com Cc: kozerkov@parallels.com Cc: lenb@kernel.org Cc: lguest@lists.ozlabs.org Cc: linux-acpi@vger.kernel.org Cc: lv.zheng@intel.com Cc: matt@codeblueprint.co.uk Cc: mbizon@freebox.fr Cc: rjw@rjwysocki.net Cc: robert.moore@intel.com Cc: rusty@rustcorp.com.au Cc: tiwai@suse.de Cc: toshi.kani@hp.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/1460592286-300-5-git-send-email-mcgrof@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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7b956f03 |
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05-Oct-2015 |
Andy Lutomirski <luto@kernel.org> |
x86/asm: Re-add parts of the manual CFI infrastructure Commit: 131484c8da97 ("x86/debug: Remove perpetually broken, unmaintainable dwarf annotations") removed all the manual DWARF annotations outside the vDSO. It also removed the macros we used for the manual annotations. Re-add these macros so that we can clean up the vDSO annotations. Signed-off-by: Andy Lutomirski <luto@kernel.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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/4c70bb98a8b773c8ccfaabf6745e569ff43e7f65.1444091584.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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e38b6b7f |
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10-Sep-2015 |
tim <tim.c.chen@linux.intel.com> |
crypto: x86/sha - Add build support for Intel SHA Extensions optimized SHA1 and SHA256 This patch provides the configuration and build support to include and build the optimized SHA1 and SHA256 update transforms for the kernel's crypto library. Originally-by: Chandramouli Narayanan <mouli_7982@yahoo.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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6c36dfe9 |
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12-Aug-2015 |
Borislav Petkov <bp@suse.de> |
x86/ras: Move AMD MCE injector to arch/x86/ras/ This is an x86-specific module and would benefit from being closer to the arch code. Move it there. Update copyright while at it. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Link: http://lkml.kernel.org/r/1439396985-12812-14-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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b2c51106 |
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21-Jul-2015 |
Andy Lutomirski <luto@kernel.org> |
x86/build: Fix detection of GCC -mpreferred-stack-boundary support As per: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383 GCC only allows -mpreferred-stack-boundary=3 on x86_64 if -mno-sse is set. That means that cc-option will not detect -mpreferred-stack-boundary=3 support, because we test for it before setting -mno-sse. Fix it by reordering the Makefile bits. Compile-tested only. This should help avoid code generation issues such as the one that was worked around in: b96fecbfa8c8 ("x86/fpu: Fix boot crash in the early FPU code") I'm a bit concerned that we could still have problems on older GCC versions given that our asm code does not respect GCC's idea of the ABI-required stack alignment. Signed-off-by: Andy Lutomirski <luto@kernel.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: Jan Kara <jack@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/f5297c192969adfa0d28b84cf8a22d59573db26d.1436126872.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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1f57d5d8 |
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03-Jun-2015 |
Ingo Molnar <mingo@kernel.org> |
x86/asm/entry: Move the arch/x86/syscalls/ definitions to arch/x86/entry/syscalls/ The build time generated syscall definitions are entry code related, move them into the arch/x86/entry/ directory. Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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d603c8e1 |
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03-Jun-2015 |
Ingo Molnar <mingo@kernel.org> |
x86/asm/entry, x86/vdso: Move the vDSO code to arch/x86/entry/vdso/ Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
131484c8 |
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27-May-2015 |
Ingo Molnar <mingo@kernel.org> |
x86/debug: Remove perpetually broken, unmaintainable dwarf annotations So the dwarf2 annotations in low level assembly code have become an increasing hindrance: unreadable, messy macros mixed into some of the most security sensitive code paths of the Linux kernel. These debug info annotations don't even buy the upstream kernel anything: dwarf driven stack unwinding has caused problems in the past so it's out of tree, and the upstream kernel only uses the much more robust framepointers based stack unwinding method. In addition to that there's a steady, slow bitrot going on with these annotations, requiring frequent fixups. There's no tooling and no functionality upstream that keeps it correct. So burn down the sick forest, allowing new, healthier growth: 27 files changed, 350 insertions(+), 1101 deletions(-) Someone who has the willingness and time to do this properly can attempt to reintroduce dwarf debuginfo in x86 assembly code plus dwarf unwinding from first principles, with the following conditions: - it should be maximally readable, and maximally low-key to 'ordinary' code reading and maintenance. - find a build time method to insert dwarf annotations automatically in the most common cases, for pop/push instructions that manipulate the stack pointer. This could be done for example via a preprocessing step that just looks for common patterns - plus special annotations for the few cases where we want to depart from the default. We have hundreds of CFI annotations, so automating most of that makes sense. - it should come with build tooling checks that ensure that CFI annotations are sensible. We've seen such efforts from the framepointer side, and there's no reason it couldn't be done on the dwarf side. 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: Frédéric Weisbecker <fweisbec@gmail.com Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan Beulich <JBeulich@suse.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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52648e83 |
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16-May-2015 |
Ingo Molnar <mingo@kernel.org> |
x86: Pack loops tightly as well Packing loops tightly (-falign-loops=1) is beneficial to code size: text data bss dec filename 12566391 1617840 1089536 15273767 vmlinux.align.16-byte 12224951 1617840 1089536 14932327 vmlinux.align.1-byte 11976567 1617840 1089536 14683943 vmlinux.align.1-byte.funcs-1-byte 11903735 1617840 1089536 14611111 vmlinux.align.1-byte.funcs-1-byte.loops-1-byte Which reduces the size of the kernel by another 0.6%, so the the total combined size reduction of the alignment-packing patches is ~5.5%. The x86 decoder bandwidth and caching arguments laid out in: be6cb02779ca ("x86: Align jump targets to 1-byte boundaries") apply to loop alignment as well. Furtermore, modern CPU uarchs have a loop cache/buffer that is a L0 cache before even any uop cache, covering a few dozen most recently executed instructions. This loop cache generally does not have the 16-byte alignment restrictions of the uop cache. Now loop alignment can still be beneficial if: - a loop is cache-hot and its surroundings are not. - if the loop is so cache hot that the instruction flow becomes x86 decoder bandwidth limited But loop alignment is harmful if: - a loop is cache-cold - a loop's surroundings are cache-hot as well - two cache-hot loops are close to each other - if the loop fits into the loop cache - if the code flow is not decoder bandwidth limited and I'd argue that the latter five scenarios are much more common in the kernel, as our hottest loops are typically: - pointer chasing: this should fit into the loop cache in most cases and is typically data cache and address generation limited - generic memory ops (memset, memcpy, etc.): these generally fit into the loop cache as well, and are likewise data cache limited. So this patch packs loop addresses tightly as well. Acked-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jason Low <jason.low2@hp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: http://lkml.kernel.org/r/20150410123017.GB19918@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
be6cb027 |
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10-Apr-2015 |
Ingo Molnar <mingo@kernel.org> |
x86: Align jump targets to 1-byte boundaries The following NOP in a hot function caught my attention: > 5a: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) That's a dead NOP that bloats the function a bit, added for the default 16-byte alignment that GCC applies for jump targets. I realize that x86 CPU manufacturers recommend 16-byte jump target alignments (it's in the Intel optimization manual), to help their relatively narrow decoder prefetch alignment and uop cache constraints, but the cost of that is very significant: text data bss dec filename 12566391 1617840 1089536 15273767 vmlinux.align.16-byte 12224951 1617840 1089536 14932327 vmlinux.align.1-byte By using 1-byte jump target alignment (i.e. no alignment at all) we get an almost 3% reduction in kernel size (!) - and a probably similar reduction in I$ footprint. Now, the usual justification for jump target alignment is the following: - modern decoders tend to have 16-byte (effective) decoder prefetch windows. (AMD documents it higher but measurements suggest the effective prefetch window on curretn uarchs is still around 16 bytes) - on Intel there's also the uop-cache with cachelines that have 16-byte granularity and limited associativity. - older x86 uarchs had a penalty for decoder fetches that crossed 16-byte boundaries. These limits are mostly gone from recent uarchs. So if a forward jump target is aligned to cacheline boundary then prefetches will start from a new prefetch-cacheline and there's higher chance for decoding in fewer steps and packing tightly. But I think that argument is flawed for typical optimized kernel code flows: forward jumps often go to 'cold' (uncommon) pieces of code, and aligning cold code to cache lines does not bring a lot of advantages (they are uncommon), while it causes collateral damage: - their alignment 'spreads out' the cache footprint, it shifts followup hot code further out - plus it slows down even 'cold' code that immediately follows 'hot' code (like in the above case), which could have benefited from the partial cacheline that comes off the end of hot code. But even in the cache-hot case the 16 byte alignment brings disadvantages: - it spreads out the cache footprint, possibly making the code fall out of the L1 I$. - On Intel CPUs, recent microarchitectures have plenty of uop cache (typically doubling every 3 years) - while the size of the L1 cache grows much less aggressively. So workloads are rarely uop cache limited. The only situation where alignment might matter are tight loops that could fit into a single 16 byte chunk - but those are pretty rare in the kernel: if they exist they tend to be pointer chasing or generic memory ops, which both tend to be cache miss (or cache allocation) intensive and are not decoder bandwidth limited. So the balance of arguments strongly favors packing kernel instructions tightly versus maximizing for decoder bandwidth: this patch changes the jump target alignment from 16 bytes to 1 byte (tightly packed, unaligned). Acked-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jason Low <jason.low2@hp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Link: http://lkml.kernel.org/r/20150410120846.GA17101@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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d9ee948d |
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17-Dec-2014 |
H.J. Lu <hjl.tools@gmail.com> |
x86/asm: Use -mskip-rax-setup if supported GCC 5 added a compiler option, -mskip-rax-setup, for x86-64. It skips setting up the RAX register when SSE is disabled and there are no variable arguments passed in vector registers. (According to the x86_64 ABI, %al is used as a hidden register containing the number of vector registers used). Since the kernel doesn't pass vector registers to functions with variable arguments, this option can be used to optimize the x86-64 kernel. This GCC feature was suggested by Rasmus Villemoes <linux@rasmusvillemoes.dk>. This is the corresponding kernel change using it. For kernel v3.17: text data bss dec filename 11455921 2204048 5853184 19513153 vmlinux #with -mskip-rax-setup 11480079 2204048 5853184 19537311 vmlinux For Kernel v4.0+ - custom config: text data bss dec filename 10231778 3479800 16617472 30329050 vmlinux-gcc5+-mskip-rax-setup 10268797 3547448 16621568 30437813 vmlinux Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> 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: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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a436bb7b |
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27-Mar-2015 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
kbuild: use relative path more to include Makefile Prior to this commit, it was impossible to use relative path to include Makefiles from the top level Makefile because the option "--include-dir=$(srctree)" becomes effective when Make enters into sub Makefiles. To use relative path in any places, this commit moves the option above the "sub-make" target. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
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75aaf4c3 |
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23-Jan-2015 |
Jan Beulich <JBeulich@suse.com> |
x86/raid6: correctly check for assembler capabilities Just like for AVX2 (which simply needs an #if -> #ifdef conversion), SSSE3 assembler support should be checked for before using it. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NeilBrown <neilb@suse.de>
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#
5c630089 |
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10-Sep-2014 |
Rasmus Villemoes <linux@rasmusvillemoes.dk> |
x86/kbuild: Eliminate duplicate command line options The options -mno-mmx and -mno-sse are unconditionally added to KBUILD_CFLAGS in both branches of an ifeq and through a $(cc-option) further down. We can safely remove the first instances. In fact, since the -mno-mmx and -mno-sse options were introduced simultaneous with the other two options in the $(cc-option) [according to http://www.gnu.org/software/gcc/gcc-3.1/changes.html], and since the former were unconditionally used, one can deduce that only gcc versions knowing about all four are supported. So also eliminate the $(cc-option) wrap. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Peter Foley <pefoley2@pefoley.com> Link: http://lkml.kernel.org/r/1410365139-24440-1-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
b0108f9e |
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29-Aug-2014 |
Michael Welling <mwelling@ieee.org> |
kexec: purgatory: add clean-up for purgatory directory Without this patch the kexec-purgatory.c and purgatory.ro files are not removed after make mrproper. Signed-off-by: Michael Welling <mwelling@ieee.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
74ca317c |
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29-Aug-2014 |
Vivek Goyal <vgoyal@redhat.com> |
kexec: create a new config option CONFIG_KEXEC_FILE for new syscall Currently new system call kexec_file_load() and all the associated code compiles if CONFIG_KEXEC=y. But new syscall also compiles purgatory code which currently uses gcc option -mcmodel=large. This option seems to be available only gcc 4.4 onwards. Hiding new functionality behind a new config option will not break existing users of old gcc. Those who wish to enable new functionality will require new gcc. Having said that, I am trying to figure out how can I move away from using -mcmodel=large but that can take a while. I think there are other advantages of introducing this new config option. As this option will be enabled only on x86_64, other arches don't have to compile generic kexec code which will never be used. This new code selects CRYPTO=y and CRYPTO_SHA256=y. And all other arches had to do this for CONFIG_KEXEC. Now with introduction of new config option, we can remove crypto dependency from other arches. Now CONFIG_KEXEC_FILE is available only on x86_64. So whereever I had CONFIG_X86_64 defined, I got rid of that. For CONFIG_KEXEC_FILE, instead of doing select CRYPTO=y, I changed it to "depends on CRYPTO=y". This should be safer as "select" is not recursive. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Tested-by: Shaun Ruffell <sruffell@digium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
3aaefce1 |
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06-Aug-2014 |
Josh Triplett <josh@joshtriplett.org> |
x86, platform, kconfig: move kvmconfig functionality to a helper The new mergeconfig helper makes it easier to add other partial configurations similar to kvmconfig. Architecture-independent portions of those partial configurations should go in kernel/configs/${name}.config, and architecture-dependent portions should go in arch/${arch}/configs/${name}.config. Based on a patch by Luis R. Rodriguez <mcgrof@suse.com>. Originally-Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Modified to make the helper name more general than just virtualization, support architecture-dependent and architecture-independent partial configurations, move the helper and kvmconfig to scripts/kconfig/Makefile, and factor out more of the common file path. Signed-off-by: Josh Triplett <josh@joshtriplett.org>
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#
8fc5b4d4 |
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08-Aug-2014 |
Vivek Goyal <vgoyal@redhat.com> |
purgatory: core purgatory functionality Create a stand alone relocatable object purgatory which runs between two kernels. This name, concept and some code has been taken from kexec-tools. Idea is that this code runs after a crash and it runs in minimal environment. So keep it separate from rest of the kernel and in long term we will have to practically do no maintenance of this code. This code also has the logic to do verify sha256 hashes of various segments which have been loaded into memory. So first we verify that the kernel we are jumping to is fine and has not been corrupted and make progress only if checsums are verified. This code also takes care of copying some memory contents to backup region. [sfr@canb.auug.org.au: run host built programs from objtree] Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
a9cfccee |
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04-Jun-2014 |
H. Peter Anvin <hpa@linux.intel.com> |
x86, build: Change code16gcc.h from a C header to an assembly header By changing code16gcc.h from a C header to an assembly header and use the -Wa,... option to gcc to force it to be added to the assembly input, we can avoid the problems with gcc reordering code bits on us. If we have -m16, we still use it, of course. Suggested-by: Kevin O'Connor <kevin@koconnor.net> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/n/tip-xw8ibgdemucl9fz3i1bymu6w@git.kernel.org
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#
14262d67 |
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07-May-2014 |
George Spelvin <linux@horizon.com> |
x86-64, build: Fix stack protector Makefile breakage with 32-bit userland If you are using a 64-bit kernel with 32-bit userland, then scripts/gcc-x86_64-has-stack-protector.sh invokes 32-bit gcc with -mcmodel=kernel, which produces: <stdin>:1:0: error: code model 'kernel' not supported in the 32 bit mode and trips the "broken compiler" test at arch/x86/Makefile:120. There are several places a fix is possible, but the following seems cleanest. (But it's minimal; it would also be possible to factor out a bunch of stuff from the two branches of the if.) Signed-off-by: George Spelvin <linux@horizon.com> Link: http://lkml.kernel.org/r/20140507210552.7581.qmail@ns.horizon.com Cc: <stable@vger.kernel.org> # v3.14 Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
8f2dd677 |
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21-Apr-2014 |
Behan Webster <behanw@converseincode.com> |
x86: LLVMLinux: Wrap -mno-80387 with cc-option Wrap -mno-80387 gcc options with cc-option so they don't break clang. Signed-off-by: Behan Webster <behanw@converseincode.com> Cc: torvalds@linux-foundation.org Cc: dwmw2@infradead.org Cc: pageexec@freemail.hu Link: http://lkml.kernel.org/r/1398145227-25053-1-git-send-email-behanw@converseincode.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
f9636404 |
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13-Apr-2014 |
Antonio Borneo <borneo.antonio@gmail.com> |
x86/platform: Fix "make O=dir kvmconfig" Running: make O=dir x86_64_defconfig make O=dir kvmconfig the second command dirties the source tree with file ".config", symlink "source" and objects in folder "scripts". Fixed by using properly prefixed paths in the arch Makefile. Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com> Acked-by: Borislav Petkov <bp@suse.de> Cc: Pekka Enberg <penberg@kernel.org> Link: http://lkml.kernel.org/r/1397377568-8375-1-git-send-email-borneo.antonio@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
fd2d0a19 |
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19-Oct-2013 |
Jan-Simon Möller <dl9pf@gmx.de> |
x86 kbuild: LLVMLinux: More cc-options added for clang Protect more options for x86 with cc-option so that we don't get errors when using clang instead of gcc. Add more or different options when using clang as well. Also need to enforce that SSE is off for clang and the stack is 8-byte aligned. Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de> Signed-off-by: Behan Webster <behanw@converseincode.com> Signed-off-by: Mark Charlebois <charlebm@gmail.com>
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#
06325190 |
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27-Feb-2014 |
Jan Beulich <JBeulich@suse.com> |
x86, hash: Fix build failure with older binutils Just like for other ISA extension instruction uses we should check whether the assembler actually supports them. The fallback here simply is to encode an instruction with fixed operands (%eax and %ecx). [ hpa: tagging for -stable as a build fix ] Signed-off-by: Jan Beulich <jbeulich@suse.com> Link: http://lkml.kernel.org/r/530F0996020000780011FBE7@nat28.tlf.novell.com Cc: Francesco Fusco <ffusco@redhat.com> Cc: Thomas Graf <tgraf@redhat.com> Cc: David S. Miller <davem@davemloft.net> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: <stable@vger.kernel.org> # v3.14
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#
b399fe35 |
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04-Feb-2014 |
Borislav Petkov <bp@suse.de> |
x86: Disable generation of traditional x87 instructions We recently had the case where wrongly used floating-constant 'E' caused the generation of traditional x87 instructions in kernel code and wreaking all kinds of havoc. Disable the generation of those too. This will save people a lot of time when trying to debug such issues by erroring out of the build instead of let them manifest themselves in very spectacular and happy-crappy ways at runtime. We're using -mno-fp-ret-in-387 in addition to -mno-80387 (which is == -msoft-float) because, as the gcc manpage says: On machines where a function returns floating-point results in the 80387 register stack, some floating-point opcodes may be emitted even if -msoft-float is used. so we want to turn off *all* non-integer instructions involving any architectural FPU state, unless it is absolutely necessary (and those cases need special handling anyway). Cc: Jiri Kosina <jkosina@suse.cz> Cc: Michael Matz <matz@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1391561711-3023-1-git-send-email-bp@alien8.de Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
de3accda |
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28-Jan-2014 |
David Woodhouse <dwmw2@infradead.org> |
x86, build: Build 16-bit code with -m16 where possible Both clang 3.5 and GCC 4.9 will support this (as of r199754 and r207196 respectively). Both have been tested to produce booting kernels when the 16-bit code is built with -m16. (Modulo LLVM PR3997, at least.) [ hpa: folded test for -m16 into M16_CFLAGS ] Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Link: http://lkml.kernel.org/r/1390997807.20153.133.camel@i7.infradead.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
1c678da3 |
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08-Jan-2014 |
David Woodhouse <David.Woodhouse@intel.com> |
x86: Remove duplication of 16-bit CFLAGS Define them once in arch/x86/Makefile instead of twice. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Link: http://lkml.kernel.org/r/1389180083-23249-1-git-send-email-David.Woodhouse@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
19952a92 |
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19-Dec-2013 |
Kees Cook <keescook@chromium.org> |
stackprotector: Unify the HAVE_CC_STACKPROTECTOR logic between architectures Instead of duplicating the CC_STACKPROTECTOR Kconfig and Makefile logic in each architecture, switch to using HAVE_CC_STACKPROTECTOR and keep everything in one place. This retains the x86-specific bug verification scripts. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Michal Marek <mmarek@suse.cz> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: James Hogan <james.hogan@imgtec.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@linux-mips.org Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/1387481759-14535-2-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
8b3b005d |
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09-Dec-2013 |
H. Peter Anvin <hpa@linux.intel.com> |
x86, build: Pass in additional -mno-mmx, -mno-sse options In checkin 5551a34e5aea x86-64, build: Always pass in -mno-sse we unconditionally added -mno-sse to the main build, to keep newer compilers from generating SSE instructions from autovectorization. However, this did not extend to the special environments (arch/x86/boot, arch/x86/boot/compressed, and arch/x86/realmode/rm). Add -mno-sse to the compiler command line for these environments, and add -mno-mmx to all the environments as well, as we don't want a compiler to generate MMX code either. This patch also removes a $(cc-option) call for -m32, since we have long since stopped supporting compilers too old for the -m32 option, and in fact hardcode it in other places in the Makefiles. Reported-by: Kevin B. Smith <kevin.b.smith@intel.com> Cc: Sunil K. Pandey <sunil.k.pandey@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: H. J. Lu <hjl.tools@gmail.com> Link: http://lkml.kernel.org/n/tip-j21wzqv790q834n7yc6g80j1@git.kernel.org Cc: <stable@vger.kernel.org> # build fix only
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#
5551a34e |
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20-Nov-2013 |
H. Peter Anvin <hpa@linux.intel.com> |
x86-64, build: Always pass in -mno-sse Always pass in the -mno-sse argument, regardless if -preferred-stack-boundary is supported. We never want to generate SSE instructions in the kernel unless we *really* know what we're doing. According to H. J. Lu, any version of gcc new enough that we support it at all should handle the -mno-sse option, so just add it unconditionally. Reported-by: Kevin B. Smith <kevin.b.smith@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: H. J. Lu <hjl.tools@gmail.com> Link: http://lkml.kernel.org/n/tip-j21wzqv790q834n7yc6g80j1@git.kernel.org Cc: <stable@vger.kernel.org> # build fix only
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#
a0215061 |
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08-Jul-2013 |
Kees Cook <keescook@chromium.org> |
x86, relocs: Move ELF relocation handling to C Moves the relocation handling into C, after decompression. This requires that the decompressed size is passed to the decompression routine as well so that relocations can be found. Only kernels that need relocation support will use the code (currently just x86_32), but this is laying the ground work for 64-bit using it in support of KASLR. Based on work by Neill Clift and Michael Davidson. Signed-off-by: Kees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20130708161517.GA4832@www.outflux.net Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
fc58be75 |
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21-Jun-2013 |
Borislav Petkov <bp@suse.de> |
x86/platform: Add kvmconfig to the phony targets ... so as not to disable it with a file of the same name in the toplevel build directory. Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1371801891-23618-1-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
46ff5387 |
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22-May-2013 |
Borislav Petkov <bp@alien8.de> |
x86, platform, kvm, kconfig: Turn existing .config's into KVM-capable configs Add an config file snippet which enables additional options useful for running the kernel in a kvm guest. When you execute 'make kvmconfig' it merges those options with an already existing user config before you build the kernel. Based on an patch from the external lkvm tree. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Michal Marek <mmarek@suse.cz> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: penberg@kernel.org Cc: levinsasha928@gmail.com Cc: mtosatti@redhat.com Cc: fengguang.wu@intel.com Link: http://lkml.kernel.org/r/20130522144638.GB15085@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
ffee0de4 |
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20-Dec-2012 |
David Woodhouse <dwmw2@infradead.org> |
x86: Default to ARCH=x86 to avoid overriding CONFIG_64BIT It is easy to waste a bunch of time when one takes a 32-bit .config from a test machine and try to build it on a faster 64-bit system, and its existing setting of CONFIG_64BIT=n gets *changed* to match the build host. Similarly, if one has an existing build tree it is easy to trash an entire build tree that way. This is because the default setting for $ARCH when discovered from 'uname' is one of the legacy pre-x86-merge values (i386 or x86_64), which effectively force the setting of CONFIG_64BIT to match. We should default to ARCH=x86 instead, finally completing the merge that we started so long ago. This patch preserves the behaviour of the legacy ARCH settings for commands such as: make ARCH=x86_64 randconfig make ARCH=i386 randconfig ... since making the value of CONFIG_64BIT actually random in that situation is not desirable. In time, perhaps we can retire this legacy use of the old ARCH= values. We already have a way to override values for *any* config option, using $KCONFIG_ALLCONFIG, so it could be argued that we don't necessarily need to keep ARCH={i386,x86_64} around as a special case just for overriding CONFIG_64BIT. We'd probably at least want to add a way to override config options from the command line ('make CONFIG_FOO=y oldconfig') before we talk about doing that though. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Link: http://lkml.kernel.org/r/1356040315.3198.51.camel@shinybook.infradead.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
7056741f |
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08-Nov-2012 |
Jim Kukunas <james.t.kukunas@linux.intel.com> |
lib/raid6: Add AVX2 optimized recovery functions Optimize RAID6 recovery functions to take advantage of the 256-bit YMM integer instructions introduced in AVX2. The patch was tested and benchmarked before submission. However hardware is not yet released so benchmark numbers cannot be reported. Acked-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
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#
3ce9e53e |
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15-Oct-2012 |
Michal Marek <mmarek@suse.cz> |
kbuild: Fix accidental revert in commit fe04ddf Commit fe04ddf7c291 ("kbuild: Do not package /boot and /lib in make tar-pkg") accidentally reverted two previous kbuild commits. I don't know what I was thinking. This brings back changes made by commits 24cc7fb69a5b ("x86/kbuild: archscripts depends on scripts_basic") and c1c1a59e37da ("firmware: fix directory creation rule matching with make 3.80") Reported-by: Jan Beulich <JBeulich@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Michal Marek <mmarek@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
b1e0d8b7 |
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02-Oct-2012 |
Jean Delvare <jdelvare@suse.de> |
kbuild: Fix gcc -x syntax The correct syntax for gcc -x is "gcc -x assembler", not "gcc -xassembler". Even though the latter happens to work, the former is what is documented in the manual page and thus what gcc wrappers such as icecream do expect. This isn't a cosmetic change. The missing space prevents icecream from recognizing compilation tasks it can't handle, leading to silent kernel miscompilations. Besides me, credits go to Michael Matz and Dirk Mueller for investigating the miscompilation issue and tracking it down to this incorrect -x parameter syntax. Signed-off-by: Jean Delvare <jdelvare@suse.de> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Cc: Bernhard Walle <bernhard@bwalle.de> Cc: Michal Marek <mmarek@suse.cz> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
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#
fe04ddf7 |
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25-Sep-2012 |
Michal Marek <mmarek@suse.cz> |
kbuild: Do not package /boot and /lib in make tar-pkg There were reports of users destroying their Fedora installs by a kernel tarball that replaces the /lib -> /usr/lib symlink. Let's remove the toplevel directories from the tarball to prevent this from happening. Reported-by: Andi Kleen <andi@firstfloor.org> Suggested-by: Ben Hutchings <ben@decadent.org.uk> Cc: <stable@kernel.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
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#
24cc7fb6 |
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20-Sep-2012 |
Jeff Mahoney <jeffm@suse.de> |
x86/kbuild: archscripts depends on scripts_basic While building the SUSE kernel packages, which build the scripts, make clean, and then build everything, we have been running into spurious build failures. We tracked them down to a simple dependency issue: $ make mrproper CLEAN arch/x86/tools CLEAN scripts/basic $ cp patches/config/x86_64/desktop .config $ make archscripts HOSTCC arch/x86/tools/relocs /bin/sh: scripts/basic/fixdep: No such file or directory make[3]: *** [arch/x86/tools/relocs] Error 1 make[2]: *** [archscripts] Error 2 make[1]: *** [sub-make] Error 2 make: *** [all] Error 2 This was introduced by commit 6520fe55 (x86, realmode: 16-bit real-mode code support for relocs), which added the archscripts dependency to archprepare. This patch adds the scripts_basic dependency to the x86 archscripts. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
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#
484d90ee |
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10-Aug-2012 |
Andrew Boie <andrew.p.boie@intel.com> |
x86, build: Globally set -fno-pic GCC built with nonstandard options can enable -fpic by default. We never want this for 32-bit kernels and it will break the build. [ hpa: Notably the Android toolchain apparently does this. ] Change-Id: Iaab7d66e598b1c65ac4a4f0229eca2cd3d0d2898 Signed-off-by: Andrew Boie <andrew.p.boie@intel.com> Link: http://lkml.kernel.org/r/1344624546-29691-1-git-send-email-andrew.p.boie@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
d9b0cde9 |
|
29-May-2012 |
H.J. Lu <hjl.tools@gmail.com> |
x86-64, gcc: Use -mpreferred-stack-boundary=3 if supported On x86-64, the standard ABI requires alignment to 16 bytes. However, this is not actually necessary in the kernel (we don't do SSE except in very controlled ways); and furthermore, the standard kernel entry on x86-64 actually leaves the stack on an odd 8-byte boundary, which means that gcc will generate extra instructions to keep the stack *mis*aligned! gcc 4.8 adds an -mpreferred-stack-boundary=3 option to override this and lets us save some stack space and a handful of instructions. Note that this causes us to pass -mno-sse twice; this is redundant, but necessary since the cc-option test will fail unless -mno-sse is passed on the same command line. [ hpa: rewrote the patch description ] Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Link: http://lkml.kernel.org/r/CAMe9rOqPfy3JcZRLaUeCjBe9BVY-P6e0uaSbMi5hvS-6WwQueg@mail.gmail.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
ea4d26ae |
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21-May-2012 |
Jim Kukunas <james.t.kukunas@linux.intel.com> |
raid5: add AVX optimized RAID5 checksumming Optimize RAID5 xor checksumming by taking advantage of 256-bit YMM registers introduced in AVX. Signed-off-by: Jim Kukunas <james.t.kukunas@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
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#
b2d668da |
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21-May-2012 |
Jarkko Sakkinen <jarkko.sakkinen@intel.com> |
x86, relocs: Build clean fix relocs was not cleaned up when "make clean" is issued. This patch fixes the issue. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1337622684-6834-1-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: <stable@vger.kernel.org> v3.4
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#
6520fe55 |
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08-May-2012 |
H. Peter Anvin <hpa@linux.intel.com> |
x86, realmode: 16-bit real-mode code support for relocs tool A new option is added to the relocs tool called '--realmode'. This option causes the generation of 16-bit segment relocations and 32-bit linear relocations for the real-mode code. When the real-mode code is moved to the low-memory during kernel initialization, these relocation entries can be used to relocate the code properly. In the assembly code 16-bit segment relocations must be relative to the 'real_mode_seg' absolute symbol. Linear relocations must be relative to a symbol prefixed with 'pa_'. 16-bit segment relocation is used to load cs:ip in 16-bit code. Linear relocations are used in the 32-bit code for relocatable data references. They are declared in the linker script of the real-mode code. The relocs tool is moved to arch/x86/tools/relocs.c, and added new target archscripts that can be used to build scripts needed building an architecture. be compiled before building the arch/x86 tree. [ hpa: accelerating this because it detects invalid absolute relocations, a serious bug in binutils 2.22.52.0.x which currently produces bad kernels. ] Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-2-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: <stable@vger.kernel.org>
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#
f2604c14 |
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08-May-2012 |
Jarkko Sakkinen <jarkko.sakkinen@intel.com> |
x86, realmode: move relocs from scripts/ to arch/x86/tools Moved relocs tool from scripts/ to arch/x86/tools because it is architecture specific script. Added new target archscripts that can be used to build scripts needed building an architecture. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-22-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Michal Marek <mmarek@suse.cz>
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#
45046892 |
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03-May-2012 |
Thomas Gleixner <tglx@linutronix.de> |
x86: Use generic init_task Same code. Use the generic version. The special Makefile treatment is pointless anyway as init_task.o contains only data which is handled by the linker script. So no point on being treated like head text. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20120503085035.739963562@linutronix.de Cc: x86@kernel.org
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#
c0e9afc0 |
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28-Mar-2012 |
Andi Kleen <ak@linux.intel.com> |
x86: Use -mno-avx when available On gccs that support AVX it's a good idea to disable that too, similar to how SSE2, SSE1 etc. are already disabled. This prevents the compiler from generating AVX ever implicitely. No failure observed, just from review. [ hpa: Marking this for urgent and stable, simply because the patch will either have absolutely no effect *or* it will avoid potentially very hard to debug failures. ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1332960678-11879-1-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: <stable@vger.kernel.org>
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#
8bd69c2d |
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28-Feb-2012 |
Ingo Molnar <mingo@elte.hu> |
x86/x32: Fix the binutils auto-detect Fix: arch/x86/Makefile:96: *** recipe commences before first target. Stop. Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: H. J. Lu <hjl.tools@gmail.com> Link: http://lkml.kernel.org/r/1329696488-16970-1-git-send-email-hpa@zytor.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
0bf62763 |
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27-Feb-2012 |
H. Peter Anvin <hpa@linux.intel.com> |
x32: Warn and disable rather than error if binutils too old If X32 is enabled in .config, but the binutils can't build it, issue a warning and disable the feature rather than erroring out. In order to support this, have CONFIG_X86_X32 be the option set in Kconfig, and CONFIG_X86_X32_ABI be the option set by the Makefile when it is enabled and binutils has been found to be functional. Requested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: H. J. Lu <hjl.tools@gmail.com> Link: http://lkml.kernel.org/r/1329696488-16970-1-git-send-email-hpa@zytor.com
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#
303395ac |
|
11-Nov-2011 |
H. Peter Anvin <hpa@linux.intel.com> |
x86: Generate system call tables and unistd_*.h from tables Generate system call tables and unistd_*.h automatically from the tables in arch/x86/syscalls. All other information, like NR_syscalls, is auto-generated, some of which is in asm-offsets_*.c. This allows us to keep all the system call information in one place, and allows for kernel space and user space to see different information; this is currently used for the ia32 system call numbers when building the 64-bit kernel, but will be used by the x32 ABI in the near future. This also removes some gratuitious differences between i386, x86-64 and ia32; in particular, now all system call tables are generated with the same mechanism. Cc: H. J. Lu <hjl.tools@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
d7acb92f |
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13-Oct-2010 |
H. Peter Anvin <hpa@linux.intel.com> |
x86-64, asm: If the assembler supports fxsave64, use it Kbuild allows for us to probe for the existence of specific constructs in the assembler, use them to find out if we can use fxsave64 and permit the compiler to generate better code. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
08c2b394 |
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13-Sep-2010 |
basile@opensource.dyc.edu <basile@opensource.dyc.edu> |
x86, build: Disable -fPIE when compiling with CONFIG_CC_STACKPROTECTOR=y The arch/x86/Makefile uses scripts/gcc-x86_$(BITS)-has-stack-protector.sh to check if cc1 supports -fstack-protector. When -fPIE is passed to cc1, these scripts fail causing stack protection to be disabled even when it is available. This fix is similar to commit c47efe5548abbf53c2f66e06dcb46183b11d6b22 Reported-by: Kai Dietrich <mail@cleeus.de> Signed-off-by: Magnus Granberg <zorry@gentoo.org> LKML-Reference: <20100913101319.748A1148E216@opensource.dyc.edu> Signed-off-by: Anthony G. Basile <basile@opensource.dyc.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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#
9e565292 |
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13-May-2010 |
Roland McGrath <roland@redhat.com> |
x86: Use .cfi_sections for assembly code The newer assemblers support the .cfi_sections directive so we can put the CFI from .S files into the .debug_frame section that is preserved in unstripped vmlinux and in separate debuginfo, rather than the .eh_frame section that is now discarded by vmlinux.lds.S. Signed-off-by: Roland McGrath <roland@redhat.com> LKML-Reference: <20100514044303.A6FE7400BE@magilla.sf.frob.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
477346ff |
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07-Jan-2010 |
Dave Airlie <airlied@redhat.com> |
x86-64: Allow fbdev primary video code For some reason the 64-bit tree was doing this differently and I can't see why it would need to. This correct behaviour when you have two GPUs plugged in and 32-bit put the console in one place and 64-bit in another. Signed-off-by: Dave Airlie <airlied@redhat.com> LKML-Reference: <1262847894-27498-1-git-send-email-airlied@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
14a3f40a |
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23-Oct-2009 |
Arjan van de Ven <arjan@infradead.org> |
x86: Remove STACKPROTECTOR_ALL STACKPROTECTOR_ALL has a really high overhead (runtime and stack footprint) and is not really worth it protection wise (the normal STACKPROTECTOR is in effect for all functions with buffers already), so lets just remove the option entirely. Reported-by: Dave Jones <davej@redhat.com> Reported-by: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Eric Sandeen <sandeen@redhat.com> LKML-Reference: <20091023073101.3dce4ebb@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
caa27b66 |
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20-Jul-2009 |
Sam Ravnborg <sam@ravnborg.org> |
kbuild: use INSTALLKERNEL to select customized installkernel script Replace the use of CROSS_COMPILE to select a customized installkernel script with the possibility to set INSTALLKERNEL to select a custom installkernel script when running make: make INSTALLKERNEL=arm-installkernel install With this patch we are now more consistent across different architectures - they did not all support use of CROSS_COMPILE. The use of CROSS_COMPILE was a hack as this really belongs to gcc/binutils and the installkernel script does not change just because we change toolchain. The use of CROSS_COMPILE caused troubles with an upcoming patch that saves CROSS_COMPILE when a kernel is built - it would no longer be installable. [Thanks to Peter Z. for this hint] This patch undos what Ian did in commit: 0f8e2d62fa04441cd12c08ce521e84e5bd3f8a46 ("use ${CROSS_COMPILE}installkernel in arch/*/boot/install.sh") The patch has been lightly tested on x86 only - but all changes looks obvious. Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Mike Frysinger <vapier@gentoo.org> [blackfin] Acked-by: Russell King <linux@arm.linux.org.uk> [arm] Acked-by: Paul Mundt <lethal@linux-sh.org> [sh] Acked-by: "H. Peter Anvin" <hpa@zytor.com> [x86] Cc: Ian Campbell <icampbell@arcom.com> Cc: Tony Luck <tony.luck@intel.com> [ia64] Cc: Fenghua Yu <fenghua.yu@intel.com> [ia64] Cc: Hirokazu Takata <takata@linux-m32r.org> [m32r] Cc: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Cc: Kyle McMartin <kyle@mcmartin.ca> [parisc] Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> [powerpc] Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> [s390] Cc: Thomas Gleixner <tglx@linutronix.de> [x86] Cc: Ingo Molnar <mingo@redhat.com> [x86] Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
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#
23386d63 |
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29-Aug-2009 |
Michal Schmidt <mschmidt@redhat.com> |
x86: Detect stack protector for i386 builds on x86_64 Stack protector support was not detected when building with ARCH=i386 on x86_64 systems: arch/x86/Makefile:80: stack protector enabled but no compiler support The "-m32" argument needs to be passed to the detection script. Signed-off-by: Michal Schmidt <mschmidt@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Arjan van de Ven <arjan@infradead.org> LKML-Reference: <20090829182718.10f566b1@leela> Signed-off-by: Ingo Molnar <mingo@elte.hu> --
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#
ca0e9bad |
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13-Aug-2009 |
Masami Hiramatsu <mhiramat@redhat.com> |
x86: X86 instruction decoder build-time selftest Add a user-space selftest of x86 instruction decoder at kernel build time. When CONFIG_X86_DECODER_SELFTEST=y, Kbuild builds a test harness of x86 instruction decoder and performs it after building vmlinux. The test compares the results of objdump and x86 instruction decoder code and check there are no differences. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Jim Keniston <jkenisto@us.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Avi Kivity <avi@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Frank Ch. Eigler <fche@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jason Baron <jbaron@redhat.com> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it> Cc: Roland McGrath <roland@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Vegard Nossum <vegard.nossum@gmail.com> LKML-Reference: <20090813203421.31965.29006.stgit@localhost.localdomain> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
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#
366d19e1 |
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21-Aug-2009 |
Tobias Doerffel <tobias.doerffel@gmail.com> |
x86: add specific support for Intel Atom architecture Add another option when selecting CPU family so the kernel can be optimized for Intel Atom CPUs. If GCC supports tuning options for Intel Atom they will be used. Signed-off-by: Tobias Doerffel <tobias.doerffel@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> LKML-Reference: <1251018457-19157-1-git-send-email-tobias.doerffel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
c7bd0414 |
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23-Jul-2009 |
Frans Pop <elendil@planet.nl> |
x86: Simplify the Makefile in a minor way through use of cc-ifversion Signed-off-by: Frans Pop <elendil@planet.nl> Acked-by: Sam Ravnborg <sam@ravnborg.org> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> LKML-Reference: <200907232056.28635.elendil@planet.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
dfec072e |
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03-Apr-2008 |
Vegard Nossum <vegard.nossum@gmail.com> |
kmemcheck: add the kmemcheck core General description: kmemcheck is a patch to the linux kernel that detects use of uninitialized memory. It does this by trapping every read and write to memory that was allocated dynamically (e.g. using kmalloc()). If a memory address is read that has not previously been written to, a message is printed to the kernel log. Thanks to Andi Kleen for the set_memory_4k() solution. Andrew Morton suggested documenting the shadow member of struct page. Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> [export kmemcheck_mark_initialized] [build fix for setup_max_cpus] Signed-off-by: Ingo Molnar <mingo@elte.hu> [rebased for mainline inclusion] Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
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#
1648e4f8 |
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17-Apr-2009 |
H. Peter Anvin <hpa@zytor.com> |
x86, kbuild: make "make install" not depend on vmlinux It is common to use "make install" in restricted environments which differ from the one which was actually used to build the kernel. In such environments it is highly undesirable to trigger a rebuild of any part of the system. Worse, the rebuild may be spurious, triggered by differences in the environment. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Sam Ravnborg <sam@ravnborg.org> LKML-Reference: <20090415234642.GA28531@uranus.ravnborg.org>
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#
d1f0ae5e |
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15-Apr-2009 |
Sam Ravnborg <sam@ravnborg.org> |
x86: standardize Kbuild rules Introducing this Kbuild file allow us to: make arch/x86/ And thus building all the core part of x86. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Jaswinder Singh Rajput <jaswinder@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
16a67919 |
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12-Mar-2009 |
H. Peter Anvin <hpa@zytor.com> |
x86: use targets in the boot Makefile instead of CLEAN_FILES Impact: cleanup Instead of using CLEAN_FILES in arch/x86/Makefile, add generated files to targets in arch/x86/boot/Makefile, so they will get naturally cleaned up by "make clean". Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
f9c5107c |
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12-Mar-2009 |
H. Peter Anvin <hpa@zytor.com> |
x86: remove additional vestiges of the zImage/bzImage split Impact: cleanup Remove targets that were used for zImage only, and Makefile infrastructure that was there to support the zImage/bzImage split. Reported-by: Paul Bolle <pebolle@tiscali.nl> LKML-Reference: <1236879901.24144.26.camel@test.thuisdomein> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
5d707e9c |
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09-Feb-2009 |
Tejun Heo <tj@kernel.org> |
stackprotector: update make rules Impact: no default -fno-stack-protector if stackp is enabled, cleanup Stackprotector make rules had the following problems. * cc support test and warning are scattered across makefile and kernel/panic.c. * -fno-stack-protector was always added regardless of configuration. Update such that cc support test and warning are contained in makefile and -fno-stack-protector is added iff stackp is turned off. While at it, prepare for 32bit support. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
6bda2c8b |
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28-Jan-2009 |
Ingo Molnar <mingo@elte.hu> |
x86: remove subarchitecture support Remove the 32-bit subarchitecture support code. All subarchitectures but Voyager have been converted. Voyager will be done later or will be removed. Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
7b387253 |
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28-Jan-2009 |
Ingo Molnar <mingo@elte.hu> |
x86: remove subarchitecture support code Remove remaining bits of the subarchitecture code. Now that all the special platforms are runtime probed and runtime handled, we can remove these facilities. Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
bb898558 |
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17-Aug-2008 |
Al Viro <viro@zeniv.linux.org.uk> |
x86, um: ... and asm-x86 move Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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#
1f972768 |
|
26-Jul-2008 |
Ingo Molnar <mingo@elte.hu> |
x86, RDC321x: add to mach-default first step to add RDC321x support to the default PC architecture. Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
62fa572f |
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10-Jul-2008 |
Ingo Molnar <mingo@elte.hu> |
x86, VisWS: turn into generic arch, remove leftover files remove leftover arch/x86/mach-visws/* files. Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
1b84e1c8 |
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10-Jul-2008 |
Ingo Molnar <mingo@elte.hu> |
x86, VisWS: turn into generic arch, flip over VISWS to generic arch this is the big move: flip over VISWS to generic arch support. From this commit on CONFIG_X86_VISWS is just another (default-disabled) option that turns on certain quirks - no other complications. Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
d49c4288 |
|
08-Jun-2008 |
Yinghai Lu <yhlu.kernel@gmail.com> |
x86: make generic arch support NUMAQ ... so it could fall back to normal numa and we'd reduce the impact of the NUMAQ subarch. NUMAQ depends on GENERICARCH also decouple genericarch numa from acpi. also make it fall back to bigsmp if apicid > 8. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
0c51a965 |
|
02-Jun-2008 |
Huang, Ying <ying.huang@intel.com> |
x86: extract common part of head32.c and head64.c into head.c This patch extracts the common part of head32.c and head64.c into head.c. Signed-off-by: Huang Ying <ying.huang@intel.com> Cc: andi@firstfloor.org Cc: mingo@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
b40a4392 |
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18-Apr-2008 |
Arjan van de Ven <arjan@linux.intel.com> |
stackprotector: turn not having the right gcc into a #warning If the user selects the stack-protector config option, but does not have a gcc that has the right bits enabled (for example because it isn't build with a glibc that supports TLS, as is common for cross-compilers, but also because it may be too old), then the runtime test fails right now. This patch adds a warning message for this scenario. This warning accomplishes two goals 1) the user is informed that the security option he selective isn't available 2) the user is suggested to turn of the CONFIG option that won't work for him, and would make the runtime test fail anyway. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
41b3eae6 |
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22-Apr-2008 |
Jan Beulich <jbeulich@novell.com> |
x86: minor polishing to top-level arch Makefile Use build target when creating compatibility link, and use $(boot) where possible. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
ee09efc3 |
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19-Mar-2008 |
Glauber de Oliveira Costa <gcosta@redhat.com> |
x86: add subarch support (for headers) to x86_64 this patch allows x86_64 to use subarch mach_ headers in practice, since x86_64 does not have any subarch, it will use mach_default. But it will allow for substantially less code duplication Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
700efc1b |
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23-Feb-2008 |
Eric W. Biederman <ebiederm@xmission.com> |
x86: introduce kernel/head32.c Copy x86_64 and add a head32.c so we can start moving early architecture initialization out of assembly. [ Sam Ravnborg <sam@ravnborg.org>: updated it to x86 ] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
3f85d63e |
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15-Feb-2008 |
Sam Ravnborg <sam@ravnborg.org> |
x86: fix vdso_install breaks user "make install" I suggest to make the vdso_install step independent as in following patch. This solves the issue at ahnd and still gives us the posibility to install the files should they be needed. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
cf7700fe |
|
09-Feb-2008 |
Rafael J. Wysocki <rjw@rjwysocki.net> |
x86 PM: move 64-bit hibernation files to arch/x86/power Move arch/x86/kernel/suspend_64.c to arch/x86/power . Move arch/x86/kernel/suspend_asm_64.S to arch/x86/power as hibernate_asm_64.S . Update purpose and copyright information in arch/x86/power/suspend_64.c and arch/x86/power/hibernate_asm_64.S . Update the Makefiles in arch/x86, arch/x86/kernel and arch/x86/power to reflect the above changes. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
1622ac23 |
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04-Feb-2008 |
Ian Campbell <ijc@hellion.org.uk> |
x86: define OBJCOPYFLAGS explicitly for each target. Do this rather than defining a global version and overriding it in almost all cases in order to make subsequent patches simpler. Signed-off-by: Ian Campbell <ijc@hellion.org.uk> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
e3c2a998 |
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31-Jan-2008 |
Steven Rostedt <rostedt@goodmis.org> |
fix directory entry in arch-x86-Makefile Doing a make randconfig I came across this error in the Makefile. This patch makes a directory out of arch/x86/mach-default for CONFIG_X86_RDC321X Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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edf88417 |
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16-Dec-2007 |
Avi Kivity <avi@qumranet.com> |
KVM: Move arch dependent files to new directory arch/x86/kvm/ This paves the way for multiple architecture support. Note that while ioapic.c could potentially be shared with ia64, it is also moved. Signed-off-by: Avi Kivity <avi@qumranet.com>
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5e3a77e9 |
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30-Jan-2008 |
Florian Fainelli <florian.fainelli@telecomint.eu> |
x86: add support for the RDC R-321x SoC This patch adds support for the RDC R-321x system-on-chip, also known as R-861x-(G). It uses the generic GPIO API and has support for the on-chip hardware watchdog. Build-fix from: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Florian Fainelli <florian.fainelli@telecomint.eu> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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37f30e21 |
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30-Jan-2008 |
Andi Kleen <ak@linux.intel.com> |
x86: document fdimage/isoimage completely in make help Add missing targets and missing options in x86 make help [ mingo@elte.hu: more whitespace cleanups ] Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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4ba7e5cd |
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30-Jan-2008 |
Sam Ravnborg <sam@ravnborg.org> |
x86: biarch support for 32 bit builds beautified There were no reason to mess around with CC, AS and LD. Fixing this up avoided duplicated option for ld. A small fixlet were needed in boot/Makefile which assumed that CC were modified. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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25dfeeb7 |
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30-Jan-2008 |
Sam Ravnborg <sam@ravnborg.org> |
x86: share more options between 32 and 64 bit build On recommendation from Andi Kleen share a few more options between 32 and 64 bit builds. A defconfig build for i386 did not show any difference in size of text and data. The additional shared options are: -Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2 -mno-3dnow Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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0a6ef376 |
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30-Jan-2008 |
Sam Ravnborg <sam@ravnborg.org> |
x86: unification of arch/x86/Makefiles Unify the 32 and 64 bit specific Makefiles. The unification was simplest to do in one step although the readability of the patch suffers a bit from this. Noteworthy remarks on the unification: - The 64 bit cpu stuff should be moved to Makefile_32.cpu but I did not feel confident doing it due to subtle differences - The use of cflags-y were abandoned since we have seen one bug where we did wrong due to missing assignment to KBUILD_CFLAGS. The cc-option marcro uses KBUILD_CFLAGS. - The "No need to remake" line are deleted. It caused "make -B" to fail - For 64 bit the sub architecture stuff is not used. - The way head64.o is specified could be nicer - but it awaits the introduction of head32.o (which seems like a win to introduce for readability) - Patch is checkpatch clean Patch is tested by doing a defconfig build for i386 and x86_64 and in both cases monitoring that only relevant files were recompiled when applying the patch. [ mingo@elte.hu: build fix ] Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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8c6531f7 |
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19-Nov-2007 |
Andreas Herrmann <aherrman@arcor.de> |
x86: correctly set UTS_MACHINE for "make ARCH=x86" For a kernel built with "make ARCH=x86" the following system information is displayed when running the new kernel $ uname -m x86 On some i386 systems (e.g. K7) we even have the following information $ uname -m x66 This is weird. The usual information for "uname -m" should be "x86_64" on 64-bit and "i386" or "i686" on 32-bit. This patch fixes the issue by setting UTS_MACHINE to "i386" for 32-bit kernel builds and to "x86_64" for 64-bit kernel builds. I.e., "x86" won't be used for UTS_MACHINE anymore. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andreas Herrmann <aherrman@arcor.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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43517854 |
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26-Nov-2007 |
Andreas Herrmann <aherrman@arcor.de> |
x86: correctly set UTS_MACHINE for "make ARCH=x86" x86: correctly set UTS_MACHINE for "make ARCH=x86" For a kernel built with "make ARCH=x86" the following system information is displayed when running the new kernel $ uname -m x86 On some i386 systems (e.g. K7) we even have the following information $ uname -m x66 This is weird. The usual information for "uname -m" should be "x86_64" on 64-bit and "i386" or "i686" on 32-bit. This patch fixes the issue by setting UTS_MACHINE to "i386" for 32-bit kernel builds and to "x86_64" for 64-bit kernel builds. I.e., "x86" won't be used for UTS_MACHINE anymore. Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andreas Herrmann <aherrman@arcor.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@redhat.com>
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d746d647 |
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12-Nov-2007 |
Sam Ravnborg <sam@ravnborg.org> |
x86: do not use $(ARCH) when not needed For x86 ARCH may say i386 or x86_64 and soon x86. Rely on CONFIG_X64_32 to select between 32/64 or just hardcode the value as appropriate. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com>
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2266cfd5 |
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25-Oct-2007 |
Sam Ravnborg <sam@ravnborg.org> |
x86: move defconfig files for i386 and x86_64 to x86 With some small changes to kconfig makefile we can now locate the defconfig files for i386 and x86_64 in the configs/ subdirectory under x86. make ARCH=i386 defconfig and make defconfig works as expected also after this change. But arch maintainers shall now update a defconfig file in the configs/ directory. Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
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74b469f2 |
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25-Oct-2007 |
Sam Ravnborg <sam@ravnborg.org> |
x86: move i386 and x86_64 Makefiles to arch/x86 Moving the ARCH specific Makefiles for i386 and x86_64 required a litle bit tweaking in the top-lvel Makefile. SRCARCH is now set in the top-level Makefile because we need this info to include the correct arch Makefile. Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
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