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3334fda6 |
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21-Feb-2024 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/boot: simplify GOT handling The end of GOT is calculated dynamically on boot. The size of GOT is calculated on build from the start and end of GOT. Avoid both calculations and use the end of GOT directly. Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
a795e5d2 |
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25-Feb-2024 |
Heiko Carstens <hca@linux.ibm.com> |
s390: vmlinux.lds.S: fix .got.plt assertion Naresh reported this build error on linux-next: s390x-linux-gnu-ld: Unexpected GOT/PLT entries detected! make[3]: *** [/builds/linux/arch/s390/boot/Makefile:87: arch/s390/boot/vmlinux.syms] Error 1 make[3]: Target 'arch/s390/boot/bzImage' not remade because of errors. The reason for the build error is an incorrect/incomplete assertion which checks the size of the .got.plt section. Similar to x86 the size is either zero or 24 bytes (three entries). See commit 262b5cae67a6 ("x86/boot/compressed: Move .got.plt entries out of the .got section") for more details. The three reserved/additional entries for s390 are described in chapter 3.2.2 of the s390x ABI [1] (thanks to Andreas Krebbel for pointing this out!). [1] https://github.com/IBM/s390x-abi/releases/download/v1.6.1/lzsabi_s390x.pdf Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Closes: https://lore.kernel.org/all/CA+G9fYvWp8TY-fMEvc3UhoVtoR_eM5VsfHj3+n+kexcfJJ+Cvw@mail.gmail.com Fixes: 30226853d6ec ("s390: vmlinux.lds.S: explicitly handle '.got' and '.plt' sections") Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
778666df |
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19-Feb-2024 |
Josh Poimboeuf <jpoimboe@kernel.org> |
s390: compile relocatable kernel without -fPIE On s390, currently kernel uses the '-fPIE' compiler flag for compiling vmlinux. This has a few problems: - It uses dynamic symbols (.dynsym), for which the linker refuses to allow more than 64k sections. This can break features which use '-ffunction-sections' and '-fdata-sections', including kpatch-build [1] and Function Granular KASLR. - It unnecessarily uses GOT relocations, adding an extra layer of indirection for many memory accesses. Instead of using '-fPIE', resolve all the relocations at link time and then manually adjust any absolute relocations (R_390_64) during boot. This is done by first telling the linker to preserve all relocations during the vmlinux link. (Note this is harmless: they are later stripped in the vmlinux.bin link.) Then use the 'relocs' tool to find all absolute relocations (R_390_64) which apply to allocatable sections. The offsets of those relocations are saved in a special section which is then used to adjust the relocations during boot. (Note: For some reason, Clang occasionally creates a GOT reference, even without '-fPIE'. So Clang-compiled kernels have a GOT, which needs to be adjusted.) On my mostly-defconfig kernel, this reduces kernel text size by ~1.3%. [1] https://github.com/dynup/kpatch/issues/1284 [2] https://gcc.gnu.org/pipermail/gcc-patches/2023-June/622872.html [3] https://gcc.gnu.org/pipermail/gcc-patches/2023-August/625986.html Compiler consideration: Gcc recently implemented an optimization [2] for loading symbols without explicit alignment, aligning with the IBM Z ELF ABI. This ABI mandates symbols to reside on a 2-byte boundary, enabling the use of the larl instruction. However, kernel linker scripts may still generate unaligned symbols. To address this, a new -munaligned-symbols option has been introduced [3] in recent gcc versions. This option has to be used with future gcc versions. Older Clang lacks support for handling unaligned symbols generated by kernel linker scripts when the kernel is built without -fPIE. However, future versions of Clang will include support for the -munaligned-symbols option. When the support is unavailable, compile the kernel with -fPIE to maintain the existing behavior. In addition to it: move vmlinux.relocs to safe relocation When the kernel is built with CONFIG_KERNEL_UNCOMPRESSED, the entire uncompressed vmlinux.bin is positioned in the bzImage decompressor image at the default kernel LMA of 0x100000, enabling it to be executed in-place. However, the size of .vmlinux.relocs could be large enough to cause an overlap with the uncompressed kernel at the address 0x100000. To address this issue, .vmlinux.relocs is positioned after the .rodata.compressed in the bzImage. Nevertheless, in this configuration, vmlinux.relocs will overlap with the .bss section of vmlinux.bin. To overcome that, move vmlinux.relocs to a safe location before clearing .bss and handling relocs. Compile warning fix from Sumanth Korikkar: When kernel is built with CONFIG_LD_ORPHAN_WARN and -fno-PIE, there are several warnings: ld: warning: orphan section `.rela.iplt' from `arch/s390/kernel/head64.o' being placed in section `.rela.dyn' ld: warning: orphan section `.rela.head.text' from `arch/s390/kernel/head64.o' being placed in section `.rela.dyn' ld: warning: orphan section `.rela.init.text' from `arch/s390/kernel/head64.o' being placed in section `.rela.dyn' ld: warning: orphan section `.rela.rodata.cst8' from `arch/s390/kernel/head64.o' being placed in section `.rela.dyn' Orphan sections are sections that exist in an object file but don't have a corresponding output section in the final executable. ld raises a warning when it identifies such sections. Eliminate the warning by placing all .rela orphan sections in .rela.dyn and raise an error when size of .rela.dyn is greater than zero. i.e. Dont just neglect orphan sections. This is similar to adjustment performed in x86, where kernel is built with -fno-PIE. commit 5354e84598f2 ("x86/build: Add asserts for unwanted sections") [sumanthk@linux.ibm.com: rebased Josh Poimboeuf patches and move vmlinux.relocs to safe location] [hca@linux.ibm.com: merged compile warning fix from Sumanth] Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Link: https://lore.kernel.org/r/20240219132734.22881-4-sumanthk@linux.ibm.com Link: https://lore.kernel.org/r/20240219132734.22881-5-sumanthk@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
a691c8a6 |
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07-Feb-2024 |
Nathan Chancellor <nathan@kernel.org> |
s390: vmlinux.lds.S: explicitly keep various sections When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are some warnings around certain ELF sections: s390-linux-ld: warning: orphan section `.dynstr' from `arch/s390/kernel/head64.o' being placed in section `.dynstr' s390-linux-ld: warning: orphan section `.dynamic' from `arch/s390/kernel/head64.o' being placed in section `.dynamic' s390-linux-ld: warning: orphan section `.hash' from `arch/s390/kernel/head64.o' being placed in section `.hash' s390-linux-ld: warning: orphan section `.gnu.hash' from `arch/s390/kernel/head64.o' being placed in section `.gnu.hash' Explicitly keep those sections like other architectures when CONFIG_RELOCATABLE is enabled, which is always true for s390. [hca@linux.ibm.com: keep sections instead of discarding] Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-4-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
30226853 |
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07-Feb-2024 |
Nathan Chancellor <nathan@kernel.org> |
s390: vmlinux.lds.S: explicitly handle '.got' and '.plt' sections When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are a lot of warnings around the GOT and PLT sections: s390-linux-ld: warning: orphan section `.plt' from `arch/s390/kernel/head64.o' being placed in section `.plt' s390-linux-ld: warning: orphan section `.got' from `arch/s390/kernel/head64.o' being placed in section `.got' s390-linux-ld: warning: orphan section `.got.plt' from `arch/s390/kernel/head64.o' being placed in section `.got.plt' s390-linux-ld: warning: orphan section `.iplt' from `arch/s390/kernel/head64.o' being placed in section `.iplt' s390-linux-ld: warning: orphan section `.igot.plt' from `arch/s390/kernel/head64.o' being placed in section `.igot.plt' s390-linux-ld: warning: orphan section `.iplt' from `arch/s390/boot/head.o' being placed in section `.iplt' s390-linux-ld: warning: orphan section `.igot.plt' from `arch/s390/boot/head.o' being placed in section `.igot.plt' s390-linux-ld: warning: orphan section `.got' from `arch/s390/boot/head.o' being placed in section `.got' Currently, only the '.got' section is actually emitted in the final binary. In a manner similar to other architectures, put the '.got' section near the '.data' section and coalesce the PLT sections, checking that the final section is zero sized, which is a safe/tested approach versus full discard. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-3-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
bdf2cd27 |
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07-Feb-2024 |
Nathan Chancellor <nathan@kernel.org> |
s390: vmlinux.lds.S: handle '.data.rel' sections explicitly When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are a lot of warnings around '.data.rel' sections: s390-linux-ld: warning: orphan section `.data.rel' from `kernel/sched/build_utility.o' being placed in section `.data.rel' s390-linux-ld: warning: orphan section `.data.rel.local' from `kernel/sched/build_utility.o' being placed in section `.data.rel.local' s390-linux-ld: warning: orphan section `.data.rel.ro' from `kernel/sched/build_utility.o' being placed in section `.data.rel.ro' s390-linux-ld: warning: orphan section `.data.rel.ro.local' from `kernel/sched/build_utility.o' being placed in section `.data.rel.ro.local' Describe these in vmlinux.lds.S so there is no more warning and the sections are placed consistently between linkers. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-2-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
70264424 |
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30-Nov-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/fpu: get rid of test_fp_ctl() It is quite subtle to use test_fp_ctl() correctly. Therefore remove it - instead copy whatever new floating point control (fpc) register values are supposed to be used into its save area. Test the validity of the new value when loading it. If the new value is invalid, load the fpc register with zero. This seems to be a the best way to approach this problem. Even though this changes behavior: - sigreturn with an invalid fpc value on the stack will succeed, and continue with zero value, instead of returning with SIGSEGV - ptraced processes will also use a zero value instead of letting the request fail with -EINVAL However all of this seems to acceptable. After all testing of the value was only implemented to avoid that user space can crash the kernel. It is not there to test values for validity; and the assumption is that there is no existing user space which is doing this. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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#
b46650d5 |
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28-Mar-2023 |
Vasily Gorbik <gor@linux.ibm.com> |
s390: make extables read-only Currently, exception tables are marked as ro_after_init. However, since they are sorted during compile time using scripts/sorttable, they can be moved to RO_DATA using the RO_EXCEPTION_TABLE_ALIGN macro, which is specifically designed for this purpose. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
557b1970 |
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09-Feb-2023 |
Vasily Gorbik <gor@linux.ibm.com> |
s390/kasan: move shadow mapping to decompressor Since regular paging structs are initialized in decompressor already move KASAN shadow mapping to decompressor as well. This helps to avoid allocating KASAN required memory in 1 large chunk, de-duplicate paging structs creation code and start the uncompressed kernel with KASAN instrumentation right away. This also allows to avoid all pitfalls accidentally calling KASAN instrumented code during KASAN initialization. Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
e9c9cb90 |
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23-Jan-2023 |
Ilya Leoshkevich <iii@linux.ibm.com> |
s390: discard .interp section When debugging vmlinux with QEMU + GDB, the following GDB error may occur: (gdb) c Continuing. Warning: Cannot insert breakpoint -1. Cannot access memory at address 0xffffffffffff95c0 Command aborted. (gdb) The reason is that, when .interp section is present, GDB tries to locate the file specified in it in memory and put a number of breakpoints there (see enable_break() function in gdb/solib-svr4.c). Sometimes GDB finds a bogus location that matches its heuristics, fails to set a breakpoint and stops. This makes further debugging impossible. The .interp section contains misleading information anyway (vmlinux does not need ld.so), so fix by discarding it. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
bb1520d5 |
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13-Dec-2022 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/mm: start kernel with DAT enabled The setup of the kernel virtual address space is spread throughout the sources, boot stages and config options like this: 1. The available physical memory regions are queried and stored as mem_detect information for later use in the decompressor. 2. Based on the physical memory availability the virtual memory layout is established in the decompressor; 3. If CONFIG_KASAN is disabled the kernel paging setup code populates kernel pgtables and turns DAT mode on. It uses the information stored at step [1]. 4. If CONFIG_KASAN is enabled the kernel early boot kasan setup populates kernel pgtables and turns DAT mode on. It uses the information stored at step [1]. The kasan setup creates early_pg_dir directory and directly overwrites swapper_pg_dir entries to make shadow memory pages available. Move the kernel virtual memory setup to the decompressor and start the kernel with DAT turned on right from the very first istruction. That completely eliminates the boot phase when the kernel runs in DAT-off mode, simplies the overall design and consolidates pgtables setup. The identity mapping is created in the decompressor, while kasan shadow mappings are still created by the early boot kernel code. Share with decompressor the existing kasan memory allocator. It decreases the size of a newly requested memory block from pgalloc_pos and ensures that kernel image is not overwritten. pgalloc_low and pgalloc_pos pointers are made preserved boot variables for that. Use the bootdata infrastructure to setup swapper_pg_dir and invalid_pg_dir directories used by the kernel later. The interim early_pg_dir directory established by the kasan initialization code gets eliminated as result. As the kernel runs in DAT-on mode only the PSW_KERNEL_BITS define gets PSW_MASK_DAT bit by default. Additionally, the setup_lowcore_dat_off() and setup_lowcore_dat_on() routines get merged, since there is no DAT-off mode stage anymore. The memory mappings are created with RW+X protection that allows the early boot code setting up all necessary data and services for the kernel being booted. Just before the paging is enabled the memory protection is changed to RO+X for text, RO+NX for read-only data and RW+NX for kernel data and the identity mapping. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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2b5a0e42 |
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12-Jan-2023 |
Peter Zijlstra <peterz@infradead.org> |
objtool/idle: Validate __cpuidle code as noinstr Idle code is very like entry code in that RCU isn't available. As such, add a little validation. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230112195540.373461409@infradead.org
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#
a494398b |
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04-Jan-2023 |
Masahiro Yamada <masahiroy@kernel.org> |
s390: define RUNTIME_DISCARD_EXIT to fix link error with GNU ld < 2.36 Nathan Chancellor reports that the s390 vmlinux fails to link with GNU ld < 2.36 since commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv"). It happens for defconfig, or more specifically for CONFIG_EXPOLINE=y. $ s390x-linux-gnu-ld --version | head -n1 GNU ld (GNU Binutils for Debian) 2.35.2 $ make -s ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- allnoconfig $ ./scripts/config -e CONFIG_EXPOLINE $ make -s ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- olddefconfig $ make -s ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- `.exit.text' referenced in section `.s390_return_reg' of drivers/base/dd.o: defined in discarded section `.exit.text' of drivers/base/dd.o make[1]: *** [scripts/Makefile.vmlinux:34: vmlinux] Error 1 make: *** [Makefile:1252: vmlinux] Error 2 arch/s390/kernel/vmlinux.lds.S wants to keep EXIT_TEXT: .exit.text : { EXIT_TEXT } But, at the same time, EXIT_TEXT is thrown away by DISCARD because s390 does not define RUNTIME_DISCARD_EXIT. I still do not understand why the latter wins after 99cb0d917ffa, but defining RUNTIME_DISCARD_EXIT seems correct because the comment line in arch/s390/kernel/vmlinux.lds.S says: /* * .exit.text is discarded at runtime, not link time, * to deal with references from __bug_table */ Nathan also found that binutils commit 21401fc7bf67 ("Duplicate output sections in scripts") cured this issue, so we cannot reproduce it with binutils 2.36+, but it is better to not rely on it. Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv") Link: https://lore.kernel.org/all/Y7Jal56f6UBh1abE@dev-arch.thelio-3990X/ Reported-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20230105031306.1455409-1-masahiroy@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
45d619bd |
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07-Dec-2022 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390: expicitly align _edata and _end symbols on page boundary Symbols _edata and _end in the linker script are the only unaligned expicitly on page boundary. Although _end is aligned implicitly by BSS_SECTION macro that is still inconsistent and could lead to a bug if a tool or function would assume that _edata is as aligned as others. For example, vmem_map_init() function does not align symbols _etext, _einittext etc. Should these symbols be unaligned as well, the size of ranges to update were short on one page. Instead of fixing every occurrence of this kind in the code and external tools just force the alignment on these two symbols. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
c9305b6c |
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26-Aug-2022 |
Josh Poimboeuf <jpoimboe@kernel.org> |
s390: fix nospec table alignments Add proper alignment for .nospec_call_table and .nospec_return_table in vmlinux. [hca@linux.ibm.com]: The problem with the missing alignment of the nospec tables exist since a long time, however only since commit e6ed91fd0768 ("s390/alternatives: remove padding generation code") and with CONFIG_RELOCATABLE=n the kernel may also crash at boot time. The above named commit reduced the size of struct alt_instr by one byte, so its new size is 11 bytes. Therefore depending on the number of cpu alternatives the size of the __alt_instructions array maybe odd, which again also causes that the addresses of the nospec tables will be odd. If the address of __nospec_call_start is odd and the kernel is compiled With CONFIG_RELOCATABLE=n the compiler may generate code that loads the address of __nospec_call_start with a 'larl' instruction. This will generate incorrect code since the 'larl' instruction only works with even addresses. In result the members of the nospec tables will be accessed with an off-by-one offset, which subsequently may lead to addressing exceptions within __nospec_revert(). Fixes: f19fbd5ed642 ("s390: introduce execute-trampolines for branches") Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Link: https://lore.kernel.org/r/8719bf1ce4a72ebdeb575200290094e9ce047bcc.1661557333.git.jpoimboe@kernel.org Cc: <stable@vger.kernel.org> # 4.16 Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
df5a95f4 |
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28-Feb-2022 |
Heiko Carstens <hca@linux.ibm.com> |
s390: remove .fixup section The only user is gone. Remove the section. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
e3ec8e0f |
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27-Sep-2021 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/boot: allocate amode31 section in decompressor The memory for amode31 section is allocated from the decompressed kernel. Instead, allocate that memory from the decompressor. This is a prerequisite to allow initialization of the virtual memory before the decompressed kernel takes over. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
8b5f08b4 |
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24-Aug-2021 |
Heiko Carstens <hca@linux.ibm.com> |
s390: fix typo in linker script Rename amod31 to amode31 like it was supposed to be. Fixes: c78d0c7484f0 ("s390: rename dma section to amode31") Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
c78d0c74 |
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04-Aug-2021 |
Heiko Carstens <hca@linux.ibm.com> |
s390: rename dma section to amode31 The dma section name is confusing, since the code which resides within that section has nothing to do with direct memory access. Instead the limitation is that the code has to run in 31 bit addressing mode, and therefore has to reside below 2GB. So the name was chosen since ZONE_DMA is the same region. To reduce confusion rename the section to amode31, which hopefully describes better what this is about. Note: this will also change vmcoreinfo strings - SDMA=... gets renamed to SAMODE31=... - EDMA=... gets renamed to EAMODE31=... Acked-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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de5012b4 |
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28-Jul-2021 |
Ilya Leoshkevich <iii@linux.ibm.com> |
s390/ftrace: implement hotpatching s390 allows hotpatching the mask of a conditional jump instruction. Make use of this feature in order to avoid the expensive stop_machine() call. The new trampolines are split in 3 stages: - A first stage is a 6-byte relative conditional long branch located at each function's entry point. Its offset always points to the second stage for the corresponding function, and its mask is either all 0s (ftrace off) or all 1s (ftrace on). The code for flipping the mask is borrowed from ftrace_{enable,disable}_ftrace_graph_caller. After flipping, ftrace_arch_code_modify_post_process() syncs with all the other CPUs by sending SIGPs. - Second stages for vmlinux are stored in a separate part of the .text section reserved by the linker script, and in dynamically allocated memory for modules. This prevents the icache pollution. The total size of second stages is about 1.5% of that of the kernel image. Putting second stages in the .bss section is possible and decreases the size of the non-compressed vmlinux, but splits the kernel 1:1 mapping, which is a bad tradeoff. Each second stage contains a call to the third stage, a pointer to the part of the intercepted function right after the first stage, and a pointer to an interceptor function (e.g. ftrace_caller). Second stages are 8-byte aligned for the future direct calls implementation. - There are only two copies of the third stage: in the .text section for vmlinux and in dynamically allocated memory for modules. It can be an expoline, which is relatively large, so inlining it into each second stage is prohibitively expensive. As a result of this organization, phoronix-test-suite with ftrace off does not show any performance degradation. Suggested-by: Sven Schnelle <svens@linux.ibm.com> Suggested-by: Vasily Gorbik <gor@linux.ibm.com> Co-developed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/r/20210728212546.128248-3-iii@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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6bda6670 |
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15-Jun-2021 |
Alexander Egorenkov <egorenar@linux.ibm.com> |
s390/boot: move dma sections from decompressor to decompressed kernel This change simplifies the task of making the decompressor relocatable. The decompressor's image contains special DMA sections between _sdma and _edma. This DMA segment is loaded at boot as part of the decompressor and then simply handed over to the decompressed kernel. The decompressor itself never uses it in any way. The primary reason for this is the need to keep the aforementioned DMA segment below 2GB which is required by architecture, and because the decompressor is always loaded at a fixed low physical address, it is guaranteed that the DMA region will not cross the 2GB memory limit. If the DMA region had been placed in the decompressed kernel, then KASLR would make this guarantee impossible to fulfill or it would be restricted to the first 2GB of memory address space. This commit moves all DMA sections between _sdma and _edma from the decompressor's image to the decompressed kernel's image. The complete DMA region is placed in the init section of the decompressed kernel and immediately relocated below 2GB at start-up before it is needed by other parts of the decompressed kernel. The relocation of the DMA region happens even if the decompressed kernel is already located below 2GB in order to keep the first implementation simple. The relocation should not have any noticeable impact on boot time because the DMA segment is only a couple of pages. After relocating the DMA sections, the kernel has to fix all references which point into it. In order to automate this, place all variables pointing into the DMA sections in a special .dma.refs section. All such variables must be defined using the new __dma_ref macro. Only variables containing addresses within the DMA sections must be placed in the new .dma.refs section. Furthermore, move the initialization of control registers from the decompressor to the decompressed kernel because some control registers reference tables that must be placed in the DMA data section to guarantee that their addresses are below 2G. Because the decompressed kernel relocates the DMA sections at startup, the content of control registers CR2, CR5 and CR15 must be updated with new addresses after the relocation. The decompressed kernel initializes all control registers early at boot and then updates the content of CR2, CR5 and CR15 as soon as the DMA relocation has occurred. This practically reverts the commit a80313ff91ab ("s390/kernel: introduce .dma sections"). Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
0290c9e3 |
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16-Nov-2020 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: use invalid asce instead of kernel asce Create a region 3 page table which contains only invalid entries, and use that via "s390_invalid_asce" instead of the kernel ASCE whenever there is either - no user address space available, e.g. during early startup - as an intermediate ASCE when address spaces are switched This makes sure that user space accesses in such situations are guaranteed to fail. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
c604abc3 |
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21-Aug-2020 |
Kees Cook <keescook@chromium.org> |
vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG The .comment section doesn't belong in STABS_DEBUG. Split it out into a new macro named ELF_DETAILS. This will gain other non-debug sections that need to be accounted for when linking with --orphan-handling=warn. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-arch@vger.kernel.org Link: https://lore.kernel.org/r/20200821194310.3089815-5-keescook@chromium.org
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#
c9174047 |
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29-Oct-2019 |
Kees Cook <keescook@chromium.org> |
vmlinux.lds.h: Replace RW_DATA_SECTION with RW_DATA Rename RW_DATA_SECTION to RW_DATA. (Calling this a "section" is a lie, since it's multiple sections and section flags cannot be applied to the macro.) Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390 Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Will Deacon <will@kernel.org> Cc: x86-ml <x86@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20191029211351.13243-14-keescook@chromium.org
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#
93240b32 |
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29-Oct-2019 |
Kees Cook <keescook@chromium.org> |
vmlinux.lds.h: Replace RO_DATA_SECTION with RO_DATA Finish renaming RO_DATA_SECTION to RO_DATA. (Calling this a "section" is a lie, since it's multiple sections and section flags cannot be applied to the macro.) Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390 Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Will Deacon <will@kernel.org> Cc: x86-ml <x86@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20191029211351.13243-13-keescook@chromium.org
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#
eaf93707 |
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29-Oct-2019 |
Kees Cook <keescook@chromium.org> |
vmlinux.lds.h: Move NOTES into RO_DATA The .notes section should be non-executable read-only data. As such, move it to the RO_DATA macro instead of being per-architecture defined. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390 Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Will Deacon <will@kernel.org> Cc: x86-ml <x86@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20191029211351.13243-11-keescook@chromium.org
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#
fbe6a8e6 |
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29-Oct-2019 |
Kees Cook <keescook@chromium.org> |
vmlinux.lds.h: Move Program Header restoration into NOTES macro In preparation for moving NOTES into RO_DATA, make the Program Header assignment restoration be part of the NOTES macro itself. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390 Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Will Deacon <will@kernel.org> Cc: x86-ml <x86@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20191029211351.13243-10-keescook@chromium.org
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#
441110a5 |
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29-Oct-2019 |
Kees Cook <keescook@chromium.org> |
vmlinux.lds.h: Provide EMIT_PT_NOTE to indicate export of .notes In preparation for moving NOTES into RO_DATA, provide a mechanism for architectures that want to emit a PT_NOTE Program Header to do so. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390 Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Will Deacon <will@kernel.org> Cc: x86-ml <x86@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20191029211351.13243-9-keescook@chromium.org
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#
6434efbd |
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29-Oct-2019 |
Kees Cook <keescook@chromium.org> |
s390: Move RO_DATA into "text" PT_LOAD Program Header In preparation for moving NOTES into RO_DATA, move RO_DATA back into the "text" PT_LOAD Program Header, as done with other architectures. The "data" PT_LOAD now starts with the writable data section. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Will Deacon <will@kernel.org> Cc: x86-ml <x86@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20191029211351.13243-7-keescook@chromium.org
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#
24350fda |
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05-Aug-2019 |
Vasily Gorbik <gor@linux.ibm.com> |
s390: put _stext and _etext into .text section Perf relies on _etext and _stext symbols being one of 't', 'T', 'v' or 'V'. Put them into .text section to guarantee that. Also moves padding to page boundary inside .text which has an effect that .text section is now padded with nops rather than 0's, which apparently has been the initial intention for specifying 0x0700 fill expression. Reported-by: Thomas Richter <tmricht@linux.ibm.com> Tested-by: Thomas Richter <tmricht@linux.ibm.com> Suggested-by: Andreas Krebbel <krebbel@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
805bc0bc |
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03-Feb-2019 |
Gerald Schaefer <gerald.schaefer@linux.ibm.com> |
s390/kernel: build a relocatable kernel This patch adds support for building a relocatable kernel with -fPIE. The kernel will be relocated to 0 early in the boot process. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
bf9921a9 |
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01-Apr-2019 |
Gerald Schaefer <gerald.schaefer@linux.ibm.com> |
s390: introduce .boot.preserved.data section Introduce .boot.preserve.data section which is similar to .boot.data and "shared" between the decompressor code and the decompressed kernel. The decompressor will store values in it, and copy over to the decompressed image before starting it. This method allows to avoid using pre-defined addresses and other hacks to pass values between those boot phases. Unlike .boot.data section .boot.preserved.data is NOT a part of init data, and hence will be preserved for the kernel life time. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
5a2e1853 |
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17-Oct-2018 |
Vasily Gorbik <gor@linux.ibm.com> |
s390: avoid vmlinux segments overlap Currently .vmlinux.info section of uncompressed vmlinux elf image is included into the data segment and load address specified as 0. That extends data segment to address 0 and makes "text" and "data" segments overlap. Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flags Align LOAD 0x0000000000001000 0x0000000000100000 0x0000000000100000 0x0000000000ead03c 0x0000000000ead03c R E 0x1000 LOAD 0x0000000000eaf000 0x0000000000000000 0x0000000000000000 0x0000000001a13400 0x000000000233b520 RWE 0x1000 NOTE 0x0000000000eae000 0x0000000000fad000 0x0000000000fad000 0x000000000000003c 0x000000000000003c 0x4 Section to Segment mapping: Segment Sections... 00 .text .notes 01 .rodata __ksymtab __ksymtab_gpl __ksymtab_strings __param __modver .data..ro_after_init __ex_table .data __bug_table .init.text .exit.text .exit.data .altinstructions .altinstr_replacement .nospec_call_table .nospec_return_table .boot.data .init.data .data..percpu .bss .vmlinux.info 02 .notes Later when vmlinux.bin is produced from vmlinux, .vmlinux.info section is removed. But elf vmlinux file, even though it is not bootable anymore, used for debugging and loadable segments overlap should be avoided. Utilize special ":NONE" phdr specification to avoid adding .vmlinux.info into loadable data segment. Also set .vmlinux.info section type to INFO, which allows to get a not-loadable info CONTENTS section. Since minimal supported version of binutils 2.20 does not have --dump-section objcopy option, make .vmlinux.info section loadable during info.bin creation to get actual section contents. Reported-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
d1b52a43 |
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10-Apr-2018 |
Vasily Gorbik <gor@linux.ibm.com> |
s390: introduce .boot.data section Introduce .boot.data section which is "shared" between the decompressor code and the decompressed kernel. The decompressor will store values in it, and copy over to the decompressed image before starting it. This method allows to avoid using pre-defined addresses and other hacks to pass values between those boot phases. .boot.data section is a part of init data, and will be freed after kernel initialization is complete. For uncompressed kernel image, .boot.data section is basically the same as .init.data Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
15426ca4 |
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11-Apr-2018 |
Vasily Gorbik <gor@linux.ibm.com> |
s390: rescue initrd as early as possible To avoid multi-stage initrd rescue operation and to simplify assumptions during early memory allocations move initrd at some final safe destination as early as possible. This would also allow us to drop .bss usage restrictions for some files. Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
369f91c3 |
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19-Jul-2018 |
Vasily Gorbik <gor@linux.ibm.com> |
s390/decompressor: rework uncompressed image info collection The kernel decompressor has to know several bits of information about uncompressed image. Currently this info is collected by running "nm" on uncompressed vmlinux + "sed" and producing sizes.h file. This method worked well, but it has several disadvantages. Obscure symbols name pattern matching is fragile. Adding new values makes pattern even longer. Logic is spread across code and make file. Limited ability to adjust symbols values (currently magic lma value of 0x100000 is always subtracted). Apart from that same pieces of information (and more) would be needed for early memory detection and features like KASLR outside of boot/compressed/ folder where sizes.h is generated. To overcome limitations new "struct vmlinux_info" has been introduced to include values needed for the decompressor and the rest of the boot code. The only static instance of vmlinux_info is produced during vmlinux link step by filling in struct fields by the linker (like it is done with input_data in boot/compressed/vmlinux.scr.lds.S). This way individual values could be adjusted with all the knowledge linker has and arithmetic it supports. Later .vmlinux.info section (which contains struct vmlinux_info) is transplanted into the decompressor image and dropped from uncompressed image altogether. While doing that replace "compressed/vmlinux.scr.lds.S" linker script (whose purpose is to rename .data section in piggy.o to .rodata.compressed) with plain objcopy command. And simplify decompressor's linker script. Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
57d15877 |
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30-Sep-2018 |
Ard Biesheuvel <ardb@kernel.org> |
s390/vmlinux.lds: Move JUMP_TABLE_DATA into output section Commit e872267b8bcbb179 ("jump_table: move entries into ro_after_init region") moved the __jump_table input section into the __ro_after_init output section, but inadvertently put the macro in the wrong place in the s390 linker script. Let's fix that. Fixes: e872267b8bcbb179 ("jump_table: move entries into ro_after_init region") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Cc: linux-s390@vger.kernel.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20180930164950.3841-1-ard.biesheuvel@linaro.org
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#
e872267b |
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19-Sep-2018 |
Ard Biesheuvel <ardb@kernel.org> |
jump_table: Move entries into ro_after_init region The __jump_table sections emitted into the core kernel and into each module consist of statically initialized references into other parts of the code, and with the exception of entries that point into init code, which are defused at post-init time, these data structures are never modified. So let's move them into the ro_after_init section, to prevent them from being corrupted inadvertently by buggy code, or deliberately by an attacker. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Jessica Yu <jeyu@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-s390@vger.kernel.org Cc: Arnd Bergmann <arnd@arndb.de> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Link: https://lkml.kernel.org/r/20180919065144.25010-9-ard.biesheuvel@linaro.org
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#
f56506ef |
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27-Jun-2018 |
Vasily Gorbik <gor@linux.ibm.com> |
s390: move _text to an actual .text start Since the uncompressed image .text section starts at 0x100000 now there is no need to redefine _text to something else to make perf happy. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
c9497864 |
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27-Jun-2018 |
Vasily Gorbik <gor@linux.ibm.com> |
s390: correct _stext offset Avoid unnecessary rewrite of psw and merge _stext into startup_continue. This allows to move _stext definition to vmlinux.lds.S, where _etext is also defined and set _stext to the actual beginning of .text at 0x100000. This fixes the problem with setting the last .text page as not-executable due to vmem_map_init relying on page alinged _stext and _etext. Fixes: bd79d6632958 ("s390/decompressor: trim the kernel image up to 1M") Reported-by: Nils Hoppmann <niho@de.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
183ab05f |
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27-Jun-2018 |
Vasily Gorbik <gor@linux.ibm.com> |
s390: get rid of the first mb of uncompressed image Instead of generating uncompressed kernel image starting at 0, filling first mb with zeros (with ".org 0x100000") and then trimming it off from vmlinux.bin before compression, simply generate a kernel image starting from 0x100000. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
94cbc0ea |
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27-Jun-2018 |
Vasily Gorbik <gor@linux.ibm.com> |
s390: put expoline execute-trampolines into .text section Currently none of the vmlinux linker script patterns in .text section match expoline execute-trampolines, and they end up as separate sections: .text.__s390_indirect_jump_r1, .text.__s390x_indirect_jump_r1use_r9, .text.__s390x_indirect_branch_4_1use_6, ... Add a pattern to match them all. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
8282cd64 |
|
12-Jun-2018 |
Vasily Gorbik <gor@linux.ibm.com> |
s390/boot: make head.S and als.c be part of the decompressor only Since uncompressed kernel image does not have to be bootable anymore, move head.S, head_kdump.S and als.c to boot/ folder and compile them in just in the decompressor. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
1c21765c |
|
09-May-2018 |
Masahiro Yamada <yamada.masahiro@socionext.com> |
s390: remove no-op macro VMLINUX_SYMBOL() VMLINUX_SYMBOL() is no-op unless CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX is defined. It has ever been selected only by BLACKFIN and METAG. VMLINUX_SYMBOL() is unneeded for s390-specific code. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
f19fbd5e |
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25-Jan-2018 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
s390: introduce execute-trampolines for branches Add CONFIG_EXPOLINE to enable the use of the new -mindirect-branch= and -mfunction_return= compiler options to create a kernel fortified against the specte v2 attack. With CONFIG_EXPOLINE=y all indirect branches will be issued with an execute type instruction. For z10 or newer the EXRL instruction will be used, for older machines the EX instruction. The typical indirect call basr %r14,%r1 is replaced with a PC relative call to a new thunk brasl %r14,__s390x_indirect_jump_r1 The thunk contains the EXRL/EX instruction to the indirect branch __s390x_indirect_jump_r1: exrl 0,0f j . 0: br %r1 The detour via the execute type instruction has a performance impact. To get rid of the detour the new kernel parameter "nospectre_v2" and "spectre_v2=[on,off,auto]" can be used. If the parameter is specified the kernel and module code will be patched at runtime. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
bc3703f2 |
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20-Nov-2017 |
Hendrik Brueckner <brueckner@linux.vnet.ibm.com> |
s390/kernel: emit CFI data in .debug_frame and discard .eh_frame sections Using perf probe and libdw on kernel modules failed to find CFI data for symbols. The CFI data is stored in the .eh_frame section. The elfutils libdw is not able to extract the CFI data correctly, because the .eh_frame section requires "non-simple" relocations for kernel modules. The suggestion is to avoid these "non-simple" relocations by emitting the CFI data in the .debug_frame section. Let gcc emit respective directives by specifying the -fno-asynchronous-unwind-tables option. Using the .debug_frame section for CFI data, the .eh_frame section becomes unused and, thus, discard it for kernel and modules builds The vDSO requires the .eh_frame section and, hence, emit the CFI data in both, the .eh_frame and .debug_frame sections. See also discussion on elfutils/libdw bugzilla: https://sourceware.org/bugzilla/show_bug.cgi?id=22452 Suggested-by: Mark Wielaard <mark@klomp.org> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
978fa72e |
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01-Nov-2017 |
Heiko Carstens <hca@linux.ibm.com> |
s390: remove named saved segment support Remove the support to create a z/VM named saved segment (NSS). This feature is not supported since quite a while in favour of jump labels, function tracing and (now) CPU alternatives. All of these features require to write to the kernel text section which is not possible if the kernel is contained within an NSS. Given that memory savings are minimal if kernel images are shared and in addition updates of shared images are painful, the NSS feature can be removed. Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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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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#
686140a1 |
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12-Oct-2017 |
Vasily Gorbik <gor@linux.vnet.ibm.com> |
s390: introduce CPU alternatives Implement CPU alternatives, which allows to optionally patch newer instructions at runtime, based on CPU facilities availability. A new kernel boot parameter "noaltinstr" disables patching. Current implementation is derived from x86 alternatives. Although ideal instructions padding (when altinstr is longer then oldinstr) is added at compile time, and no oldinstr nops optimization has to be done at runtime. Also couple of compile time sanity checks are done: 1. oldinstr and altinstr must be <= 254 bytes long, 2. oldinstr and altinstr must not have an odd length. alternative(oldinstr, altinstr, facility); alternative_2(oldinstr, altinstr1, facility1, altinstr2, facility2); Both compile time and runtime padding consists of either 6/4/2 bytes nop or a jump (brcl) + 2 bytes nop filler if padding is longer then 6 bytes. .altinstructions and .altinstr_replacement sections are part of __init_begin : __init_end region and are freed after initialization. Signed-off-by: Vasily Gorbik <gor@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
d04a4c76 |
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04-May-2017 |
Heiko Carstens <hca@linux.ibm.com> |
s390: move _text symbol to address higher than zero The perf tool assumes that kernel symbols are never present at address zero. In fact it assumes if functions that map symbols to addresses return zero, that the symbol was not found. Given that s390's _text symbol historically is located at address zero this yields at least a couple of false errors and warnings in one of perf's test cases about not present symbols ("perf test 1"). To fix this simply move the _text symbol to address 0x200, just behind the initial psw and channel program located at the beginning of the kernel image. This is now hard coded within the linker script. I tried a nicer solution which moves the initial psw and channel program into an own section. However that would move the symbols within the "real" head.text section to different addresses, since the ".org" statements within head.S are relative to the head.text section. If there is a new section in front, everything else will be moved. Alternatively I could have adjusted all ".org" statements. But this current solution seems to be the easiest one, since nobody really cares where the _text symbol is actually located. Reported-by: Zvonko Kosic <zkosic@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
906f2a51 |
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31-Mar-2017 |
Kees Cook <keescook@chromium.org> |
mm: fix section name for .data..ro_after_init A section name for .data..ro_after_init was added by both: commit d07a980c1b8d ("s390: add proper __ro_after_init support") and commit d7c19b066dcf ("mm: kmemleak: scan .data.ro_after_init") The latter adds incorrect wrapping around the existing s390 section, and came later. I'd prefer the s390 naming, so this moves the s390-specific name up to the asm-generic/sections.h and renames the section as used by kmemleak (and in the future, kernel/extable.c). Link: http://lkml.kernel.org/r/20170327192213.GA129375@beast Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> [s390 parts] Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Eddie Kovsky <ewk@edkovsky.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
57d7f939 |
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22-Mar-2016 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
s390: add no-execute support Bit 0x100 of a page table, segment table of region table entry can be used to disallow code execution for the virtual addresses associated with the entry. There is one tricky bit, the system call to return from a signal is part of the signal frame written to the user stack. With a non-executable stack this would stop working. To avoid breaking things the protection fault handler checks the opcode that caused the fault for 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn) and injects a system call. This is preferable to the alternative solution with a stub function in the vdso because it works for vdso=off and statically linked binaries as well. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
d7c19b06 |
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10-Nov-2016 |
Jakub Kicinski <kuba@kernel.org> |
mm: kmemleak: scan .data.ro_after_init Limit the number of kmemleak false positives by including .data.ro_after_init in memory scanning. To achieve this we need to add symbols for start and end of the section to the linker scripts. The problem was been uncovered by commit 56989f6d8568 ("genetlink: mark families as __ro_after_init"). Link: http://lkml.kernel.org/r/1478274173-15218-1-git-send-email-jakub.kicinski@netronome.com Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
6727ad9e |
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07-Oct-2016 |
Chris Metcalf <cmetcalf@mellanox.com> |
nmi_backtrace: generate one-line reports for idle cpus When doing an nmi backtrace of many cores, most of which are idle, the output is a little overwhelming and very uninformative. Suppress messages for cpus that are idling when they are interrupted and just emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN". We do this by grouping all the cpuidle code together into a new .cpuidle.text section, and then checking the address of the interrupted PC to see if it lies within that section. This commit suitably tags x86 and tile idle routines, and only adds in the minimal framework for other architectures. Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.com Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm] Tested-by: Petr Mladek <pmladek@suse.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
d07a980c |
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07-Jun-2016 |
Heiko Carstens <hca@linux.ibm.com> |
s390: add proper __ro_after_init support On s390 __ro_after_init is currently mapped to __read_mostly which means that data marked as __ro_after_init will not be protected. Reason for this is that the common code __ro_after_init implementation is x86 centric: the ro_after_init data section was added to rodata, since x86 enables write protection to kernel text and rodata very late. On s390 we have write protection for these sections enabled with the initial page tables. So adding the ro_after_init data section to rodata does not work on s390. In order to make __ro_after_init work properly on s390 move the ro_after_init data, right behind rodata. Unlike the rodata section it will be marked read-only later after all init calls happened. This s390 specific implementation adds new __start_ro_after_init and __end_ro_after_init labels. Everything in between will be marked read-only after the init calls happened. In addition to the __ro_after_init data move also the exception table there, since from a practical point of view it fits the __ro_after_init requirements. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
0ccb32c9 |
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28-May-2016 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: align swapper_pg_dir to 16k The segment/region table that is part of the kernel image must be properly aligned to 16k in order to make the crdte inline assembly work. Otherwise it will calculate a wrong segment/region table start address and access incorrect memory locations if the swapper_pg_dir is not aligned to 16k. Therefore define BSS_FIRST_SECTIONS in order to put the swapper_pg_dir at the beginning of the bss section and also align the bss section to 16k just like other architectures did. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
be7635e7 |
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25-Mar-2016 |
Alexander Potapenko <glider@google.com> |
arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections KASAN needs to know whether the allocation happens in an IRQ handler. This lets us strip everything below the IRQ entry point to reduce the number of unique stack traces needed to be stored. Move the definition of __irq_entry to <linux/interrupt.h> so that the users don't need to pull in <linux/ftrace.h>. Also introduce the __softirq_entry macro which is similar to __irq_entry, but puts the corresponding functions to the .softirqentry.text section. Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
5a79859a |
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12-Feb-2015 |
Heiko Carstens <hca@linux.ibm.com> |
s390: remove 31 bit support Remove the 31 bit support in order to reduce maintenance cost and effectively remove dead code. Since a couple of years there is no distribution left that comes with a 31 bit kernel. The 31 bit kernel also has been broken since more than a year before anybody noticed. In addition I added a removal warning to the kernel shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning message") which let everybody know about the plan to remove 31 bit code. We didn't get any response. Given that the last 31 bit only machine was introduced in 1999 let's remove the code. Anybody with 31 bit user space code can still use the compat mode. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
a4e69245 |
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11-Feb-2013 |
Heiko Carstens <hca@linux.ibm.com> |
s390/linker skript: discard exit.data at runtime Discard exit.data section at run time, not link time, since exit.text references exit.data and causes this build error: `.exit.data' referenced in section `.exit.text' of drivers/built-in.o: defined in discarded section `.exit.data' of drivers/built-in.o Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
c985cb37 |
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18-Oct-2012 |
Heiko Carstens <hca@linux.ibm.com> |
s390: fix linker script for 31 bit builds Because of a change in the s390 arch backend of binutils (commit 23ecd77 "Pick the default arch depending on the target size" in binutils repo) 31 bit builds will fail since the linker would now try to create 64 bit binary output. Fix this by setting OUTPUT_ARCH to s390:31-bit instead of s390. Thanks to Andreas Krebbel for figuring out the issue. Fixes this build error: LD init/built-in.o s390x-4.7.2-ld: s390:31-bit architecture of input file `arch/s390/kernel/head.o' is incompatible with s390:64-bit output Cc: Andreas Krebbel <Andreas.Krebbel@de.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
56280b1b |
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24-Jul-2012 |
Heiko Carstens <hca@linux.ibm.com> |
s390/linker script: use RO_DATA_SECTION Use RO_DATA_SECTION instead of RODATA like several other archs do already. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
e0a15d5b |
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18-Jan-2012 |
Christian Borntraeger <borntraeger@de.ibm.com> |
[S390] cleanup entry point definition The vmlinux file for s390 contains a currently unused entry point, which is specified in two different locations: the linker script and the makefile. As it happens both definitions are different and the linker file is broken (_start does not exist) and the makefile specifies an entry point which makes no sense (the SALIPL loader entry point). So lets get rid of one definition (the makefile) and use the entry point of all other ipl methods (0x10000 -> startup) to be consistent. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
7a2512b7 |
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14-Nov-2011 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] incorrect note program header 'readelf -n' on the s390 vmlinux file generates lots of warnings about corrupt notes. The reason is that the 'NOTE' program header has incorrect file and memory sizes. The problem is that the section following the NOTES section do not switch to a different phdr and they get added to the NOTE program section. Add a dummy entry to the linker script that switches to the data phdr before the start of the RODATA section. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
0415b00d1 |
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24-Mar-2011 |
Tejun Heo <tj@kernel.org> |
percpu: Always align percpu output section to PAGE_SIZE Percpu allocator honors alignment request upto PAGE_SIZE and both the percpu addresses in the percpu address space and the translated kernel addresses should be aligned accordingly. The calculation of the former depends on the alignment of percpu output section in the kernel image. The linker script macros PERCPU_VADDR() and PERCPU() are used to define this output section and the latter takes @align parameter. Several architectures are using @align smaller than PAGE_SIZE breaking percpu memory alignment. This patch removes @align parameter from PERCPU(), renames it to PERCPU_SECTION() and makes it always align to PAGE_SIZE. While at it, add PCPU_SETUP_BUG_ON() checks such that alignment problems are reliably detected and remove percpu alignment comment recently added in workqueue.c as the condition would trigger BUG way before reaching there. For um, this patch raises the alignment of percpu area. As the area is in .init, there shouldn't be any noticeable difference. This problem was discovered by David Howells while debugging boot failure on mn10300. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Mike Frysinger <vapier@gentoo.org> Cc: uclinux-dist-devel@blackfin.uclinux.org Cc: David Howells <dhowells@redhat.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: user-mode-linux-devel@lists.sourceforge.net
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#
19df0c2f |
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25-Jan-2011 |
Tejun Heo <tj@kernel.org> |
percpu: align percpu readmostly subsection to cacheline Currently percpu readmostly subsection may share cachelines with other percpu subsections which may result in unnecessary cacheline bounce and performance degradation. This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR() linker macros, makes each arch linker scripts specify its cacheline size and use it to align percpu subsections. This is based on Shaohua's x86 only patch. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Shaohua Li <shaohua.li@intel.com>
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#
dfcc3e6a |
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06-Oct-2009 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Enable kmemleak on s390. Also increase the maximum possible kmemleak early log entries since 2000 are not sufficient on s390. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
04a95f6d |
|
11-Sep-2009 |
Nelson Elhage <nelhage@ksplice.com> |
[S390] clean up linker script using new linker script macros. Note that this patch moves .data.init_task inside _edata. In addition, the alignment of .init.ramfs changes: It is now PAGE_ALIGNED and __initramfs_end is arbitrarily aligned; Previously it was only aligned to a 0x100-byte boundary, and always ended on an even byte. This change results in fewer output sections and in some data being reordered, but should have no functional effect. Signed-off-by: Nelson Elhage <nelhage@ksplice.com> Signed-off-by: Tim Abbott <tabbott@ksplice.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
26803144 |
|
11-Sep-2009 |
Tim Abbott <tabbott@ksplice.com> |
[S390] Use macros for .data.page_aligned. .data.page_aligned should not need a separate output section, so as part of this cleanup I moved into the .data output section in the linker scripts in order to eliminate unnecessary references to the section name. Remove the reference to .data.idt, since nothing is put into the .data.idt section on the s390 architecture. It looks like Cyrill Gorcunov posted a patch to remove the .data.idt code on s390 previously: <http://lkml.indiana.edu/hypermail/linux/kernel/0802.2/2536.html> CCing him and the people who acked that patch in case there's a reason it wasn't applied. Signed-off-by: Tim Abbott <tabbott@ksplice.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
023bf6f1 |
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08-Jul-2009 |
Tejun Heo <tj@kernel.org> |
linker script: unify usage of discard definition Discarded sections in different archs share some commonality but have considerable differences. This led to linker script for each arch implementing its own /DISCARD/ definition, which makes maintaining tedious and adding new entries error-prone. This patch makes all linker scripts to move discard definitions to the end of the linker script and use the common DISCARDS macro. As ld uses the first matching section definition, archs can include default discarded sections by including them earlier in the linker script. ia64 is notable because it first throws away some ia64 specific subsections and then include the rest of the sections into the final image, so those sections must be discarded before the inclusion. defconfig compile tested for x86, x86-64, powerpc, powerpc64, ia64, alpha, sparc, sparc64 and s390. Michal Simek tested microblaze. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Mike Frysinger <vapier@gentoo.org> Tested-by: Michal Simek <monstr@monstr.eu> Cc: linux-arch@vger.kernel.org Cc: Michal Simek <monstr@monstr.eu> Cc: microblaze-uclinux@itee.uq.edu.au Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Tony Luck <tony.luck@intel.com>
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405d967d |
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24-Jun-2009 |
Tejun Heo <tj@kernel.org> |
linker script: throw away .discard section x86 throws away .discard section but no other archs do. Also, .discard is not thrown away while linking modules. Make every arch and module linking throw it away. This will be used to define dummy variables for percpu declarations and definitions. This patch is based on Ivan Kokshaysky's alpha percpu patch. [ Impact: always throw away everything in .discard ] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Bryan Wu <cooloney@kernel.org> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Tony Luck <tony.luck@intel.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: David S. Miller <davem@davemloft.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Chris Zankel <chris@zankel.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@elte.hu>
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88dbd203 |
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12-Jun-2009 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] ftrace: add function graph tracer support Function graph tracer support for s390. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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2133bb8d |
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25-Apr-2009 |
Tim Abbott <tabbott@MIT.EDU> |
s390: convert to use __HEAD and HEAD_TEXT macros. This has the consequence of changing the section name use for head code from ".text.head" to ".head.text". Since this commit changes all users in the architecture, this change should be harmless. Signed-off-by: Tim Abbott <tabbott@mit.edu> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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92e6ecf3 |
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26-Mar-2009 |
Christian Borntraeger <borntraeger@de.ibm.com> |
[S390] Fix hypervisor detection for KVM Currently we use the cpuid (via STIDP instruction) to recognize LPAR, z/VM and KVM. The architecture states, that bit 0-7 of STIDP returns all zero, and if STIDP is executed in a virtual machine, the VM operating system will replace bits 0-7 with FF. KVM should not use FE to distinguish z/VM from KVM for interested guests. The proper way to detect the hypervisor is the STSI (Store System Information) instruction, which return information about the hypervisors via function code 3, selector1=2, selector2=2. This patch changes the detection routine of Linux to use STSI instead of STIDP. This detection is earlier than bootmem, we have to use a static buffer. Since STSI expects a 4kb block (4kb aligned) this patch also changes the init.data alignment for s390. As this section will be freed during boot, this should be no problem. Patch is tested with LPAR, z/VM, KVM on LPAR, and KVM under z/VM. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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0778dc3a |
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27-Nov-2008 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Fix alignment of initial kernel stack. We need an alignment of 16384 bytes for the initial kernel stack if the kernel is configured for 16384 bytes stacks but the linker script currently guarantees only an alignment of 8192 bytes. So fix this and simply use THREAD_SIZE as alignment value which will always do the right thing. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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5453c1a5 |
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25-Aug-2008 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Fix linker script. 6360b1fbb4a939efd34fc770c2ebd927c55506e0 ("move BUG_TABLE into RODATA") causes this build bug (binutils 2.18.50.0.8.20080709, gcc 4.3.1): AS .tmp_kallsyms1.o LD .tmp_vmlinux2 KSYM .tmp_kallsyms2.S s390x-4.3.1-nm: .tmp_vmlinux2: File truncated No valid symbol. make: *** [.tmp_kallsyms2.S] Error 1 So fix this. Cc: Jan Beulich <jbeulich@novell.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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6360b1fb |
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12-May-2008 |
Jan Beulich <jbeulich@novell.com> |
move BUG_TABLE into RODATA Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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a817a61f |
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05-Feb-2008 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Fix linker script. Fixes this warning: vmlinux: warning: allocated section `.text' not in segment Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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01ba2bdc |
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20-Jan-2008 |
Sam Ravnborg <sam@ravnborg.org> |
all archs: consolidate init and exit sections in vmlinux.lds.h This patch consolidate all definitions of .init.text, .init.data and .exit.text, .exit.data section definitions in the generic vmlinux.lds.h. This is a preparational patch - alone it does not buy us much good. Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
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ea29ee16 |
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26-Jan-2008 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] Move NOTES and BUG_TABLE. Move the NOTES and BUG_TABLE section in the linker script to the read-only sections right after the text section. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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52480ee5 |
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12-Oct-2007 |
Sam Ravnborg <sam@ravnborg.org> |
[S390] s390: use PAGE_SIZE in vmlinux.lds Replace the hardcoded 4096 value with the PAGE_SIZE macro. Converted a few decimal numbers to readable hex numbers. Use of PAGE_SIZE required a small change to page.h to allow PAGE_SIZE to be used from assembler/linker scripts. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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e16af09d |
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12-Oct-2007 |
Sam Ravnborg <sam@ravnborg.org> |
[S390] s390: beautify vmlinux.lds Introduce a consistent style in vmlinux.lds. This style is gradually being introduced for all archs. A few lables were moved inside the section definition so they are assigned the correct value of gcc decide to align the content to another address than the one . has. In the past this has fixed several bugs but for s390 it will not impact due to all the alignmnet already introduced. Stabs definitions are consolidated in asm-generic/vmlinux.lds.h This patch also introduce support for DWARF - without knowing if this makes sense for s390. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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e62133b4 |
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26-Jul-2007 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Get rid of new section mismatch warnings. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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86ead9ca |
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19-Jul-2007 |
Roland McGrath <roland@redhat.com> |
s390: Put allocated ELF notes in read-only data segment This changes the s390 linker script to use the asm-generic NOTES macro so that ELF note sections with SHF_ALLOC set are linked into the kernel image along with other read-only data. The PT_NOTE also points to their location. This paves the way for putting useful build-time information into ELF notes that can be found easily later in a kernel memory dump. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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5fb7dc37 |
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19-Jul-2007 |
Fenghua Yu <fenghua.yu@intel.com> |
define new percpu interface for shared data per cpu data section contains two types of data. One set which is exclusively accessed by the local cpu and the other set which is per cpu, but also shared by remote cpus. In the current kernel, these two sets are not clearely separated out. This can potentially cause the same data cacheline shared between the two sets of data, which will result in unnecessary bouncing of the cacheline between cpus. One way to fix the problem is to cacheline align the remotely accessed per cpu data, both at the beginning and at the end. Because of the padding at both ends, this will likely cause some memory wastage and also the interface to achieve this is not clean. This patch: Moves the remotely accessed per cpu data (which is currently marked as ____cacheline_aligned_in_smp) into a different section, where all the data elements are cacheline aligned. And as such, this differentiates the local only data and remotely accessed data cleanly. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Acked-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: <linux-arch@vger.kernel.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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ca967258 |
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17-May-2007 |
Sam Ravnborg <sam@ravnborg.org> |
all-archs: consolidate .data section definition in asm-generic With this consolidation we can now modify the .data section definition in one spot for all archs. Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
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7664709b |
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12-May-2007 |
Sam Ravnborg <sam@ravnborg.org> |
all-archs: consolidate .text section definition in asm-generic Move definition of .text section to asm-generic. Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
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b6e3590f |
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02-May-2007 |
Jeremy Fitzhardinge <jeremy@goop.org> |
[PATCH] x86: Allow percpu variables to be page-aligned Let's allow page-alignment in general for per-cpu data (wanted by Xen, and Ingo suggested KVM as well). Because larger alignments can use more room, we increase the max per-cpu memory to 64k rather than 32k: it's getting a little tight. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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c0007f1a |
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27-Apr-2007 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Use generic bug. Generic bug implementation for s390. Will increase the value of the console output on BUG() statements since registers r0-r5,r14 will not be clobbered by a printk() call that was previously done before the illegal instruction of BUG() was hit. Also implements an architecture specific WARN_ON(). Output of that could be increased but requires common code change. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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67d38229 |
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10-Feb-2007 |
Jean-Paul Saman <jean-paul.saman@nxp.com> |
[PATCH] disable init/initramfs.c: architectures Update all arch/*/kernel/vmlinux.lds.S to not include space for initramfs when CONFIG_BLK_DEV_INITRAMFS is not selected. This saves another 4 kbytes on most platfoms (some reserve PAGE_SIZE for initramfs). Signed-off-by: Jean-Paul Saman <jean-paul.saman@nxp.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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162e006e |
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05-Feb-2007 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Mark kernel text section read-only. Set read-only flag in the page table entries for the kernel image text section. This will catch all instruction caused corruptions withing the text section. Instruction replacement via kprobes still works, since it bypasses now dynamic address translation. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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fe355b7f |
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05-Feb-2007 |
Hongjie Yang <hongjie@us.ibm.com> |
[S390] boot from NSS support Add support to boot from a named saved segment (NSS). Signed-off-by: Hongjie Yang <hongjie@us.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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61ce1efe |
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27-Oct-2006 |
Andrew Morton <akpm@osdl.org> |
[PATCH] vmlinux.lds: consolidate initcall sections Add a vmlinux.lds.h helper macro for defining the eight-level initcall table, teach all the architectures to use it. This is a prerequisite for a patch which performs initcall synchronisation for multithreaded-probing. Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> [ Added AVR32 as well ] Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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1375fc1f |
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20-Sep-2006 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] __exit cleanup. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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4ba069b8 |
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20-Sep-2006 |
Michael Grundy <grundym@us.ibm.com> |
[S390] add kprobes support. Signed-off-by: Michael Grundy <grundym@us.ibm.com> Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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6ab3d562 |
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30-Jun-2006 |
Jörn Engel <joern@wohnheim.fh-wedel.de> |
Remove obsolete #include <linux/config.h> Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
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58268b97 |
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27-Apr-2006 |
Christian Borntraeger <cborntra@de.ibm.com> |
[PATCH] s390: add read_mostly optimization Add a read_mostly section and define __read_mostly to prevent cache line pollution due to writes for mostly read variables. In addition fix the incorrect alignment of the cache_line_aligned data section. s390 has a cacheline size of 256 bytes. Signed-off-by: Christian Borntraeger <cborntra@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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347a8dc3 |
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06-Jan-2006 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[PATCH] s390: cleanup Kconfig Sanitize some s390 Kconfig options. We have ARCH_S390, ARCH_S390X, ARCH_S390_31, 64BIT, S390_SUPPORT and COMPAT. Replace these 6 options by S390, 64BIT and COMPAT. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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1da177e4 |
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16-Apr-2005 |
Linus Torvalds <torvalds@ppc970.osdl.org> |
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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