user/sven/linux.git/include/linux/compiler_attributes.h, branch v5.17.3

compiler_attributes.h: Add __disable_sanitizer_instrumentation

2021-12-10T00:42:28Z

The new attribute maps to __attribute__((disable_sanitizer_instrumentation)), which will be supported by Clang >= 14.0. Future support in GCC is also possible. This attribute disables compiler instrumentation for kernel sanitizer tools, making it easier to implement noinstr. It is different from the existing __no_sanitize* attributes, which may still allow certain types of instrumentation to prevent false positives. Signed-off-by: Alexander Potapenko Signed-off-by: Marco Elver Signed-off-by: Paul E. McKenney

Merge tag 'compiler-attributes-for-linus-v5.16' of git://github.com/ojeda/linux

2021-11-07T18:38:17Z

Pull compiler attributes update from Miguel Ojeda: "An improvement for `__compiletime_assert` and a trivial cleanup" * tag 'compiler-attributes-for-linus-v5.16' of git://github.com/ojeda/linux: compiler_types: mark __compiletime_assert failure as __noreturn Compiler Attributes: remove GCC 5.1 mention

Compiler Attributes: add __alloc_size() for better bounds checking

2021-11-06T20:30:33Z

GCC and Clang can use the "alloc_size" attribute to better inform the results of __builtin_object_size() (for compile-time constant values). Clang can additionally use alloc_size to inform the results of __builtin_dynamic_object_size() (for run-time values). Because GCC sees the frequent use of struct_size() as an allocator size argument, and notices it can return SIZE_MAX (the overflow indication), it complains about these call sites overflowing (since SIZE_MAX is greater than the default -Walloc-size-larger-than=PTRDIFF_MAX). This isn't helpful since we already know a SIZE_MAX will be caught at run-time (this was an intentional design). To deal with this, we must disable this check as it is both a false positive and redundant. (Clang does not have this warning option.) Unfortunately, just checking the -Wno-alloc-size-larger-than is not sufficient to make the __alloc_size attribute behave correctly under older GCC versions. The attribute itself must be disabled in those situations too, as there appears to be no way to reliably silence the SIZE_MAX constant expression cases for GCC versions less than 9.1: In file included from ./include/linux/resource_ext.h:11, from ./include/linux/pci.h:40, from drivers/net/ethernet/intel/ixgbe/ixgbe.h:9, from drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c:4: In function 'kmalloc_node', inlined from 'ixgbe_alloc_q_vector' at ./include/linux/slab.h:743:9: ./include/linux/slab.h:618:9: error: argument 1 value '18446744073709551615' exceeds maximum object size 9223372036854775807 [-Werror=alloc-size-larger-than=] return __kmalloc_node(size, flags, node); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ./include/linux/slab.h: In function 'ixgbe_alloc_q_vector': ./include/linux/slab.h:455:7: note: in a call to allocation function '__kmalloc_node' declared here void *__kmalloc_node(size_t size, gfp_t flags, int node) __assume_slab_alignment __malloc; ^~~~~~~~~~~~~~ Specifically: '-Wno-alloc-size-larger-than' is not correctly handled by GCC < 9.1 https://godbolt.org/z/hqsfG7q84 (doesn't disable) https://godbolt.org/z/P9jdrPTYh (doesn't admit to not knowing about option) https://godbolt.org/z/465TPMWKb (only warns when other warnings appear) '-Walloc-size-larger-than=18446744073709551615' is not handled by GCC < 8.2 https://godbolt.org/z/73hh1EPxz (ignores numeric value) Since anything marked with __alloc_size would also qualify for marking with __malloc, just include __malloc along with it to avoid redundant markings. (Suggested by Linus Torvalds.) Finally, make sure checkpatch.pl doesn't get confused about finding the __alloc_size attribute on functions. (Thanks to Joe Perches.) Link: https://lkml.kernel.org/r/20210930222704.2631604-3-keescook@chromium.org Signed-off-by: Kees Cook Tested-by: Randy Dunlap Cc: Andy Whitcroft Cc: Christoph Lameter Cc: Daniel Micay Cc: David Rientjes Cc: Dennis Zhou Cc: Dwaipayan Ray Cc: Joe Perches Cc: Joonsoo Kim Cc: Lukas Bulwahn Cc: Pekka Enberg Cc: Tejun Heo Cc: Vlastimil Babka Cc: Alexandre Bounine Cc: Gustavo A. R. Silva Cc: Ira Weiny Cc: Jing Xiangfeng Cc: John Hubbard Cc: kernel test robot Cc: Matt Porter Cc: Miguel Ojeda Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Souptick Joarder Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Compiler Attributes: remove GCC 5.1 mention

2021-10-21T22:50:34Z

GCC 5.1 is now the minimum version. Acked-by: Nick Desaulniers Signed-off-by: Miguel Ojeda

Merge branch 'gcc-min-version-5.1' (make gcc-5.1 the minimum version)

2021-09-13T17:43:04Z

Merge patch series from Nick Desaulniers to update the minimum gcc version to 5.1. This is some of the left-overs from the merge window that I didn't want to deal with yesterday, so it comes in after -rc1 but was sent before. Gcc-4.9 support has been an annoyance for some time, and with -Werror I had the choice of applying a fairly big patch from Kees Cook to remove a fair number of initializer warnings (still leaving some), or this patch series from Nick that just removes the source of the problem. The initializer cleanups might still be worth it regardless, but honestly, I preferred just tackling the problem with gcc-4.9 head-on. We've been more aggressiuve about no longer having to care about compilers that were released a long time ago, and I think it's been a good thing. I added a couple of patches on top to sort out a few left-overs now that we no longer support gcc-4.x. As noted by Arnd, as a result of this minimum compiler version upgrade we can probably change our use of '--std=gnu89' to '--std=gnu11', and finally start using local loop declarations etc. But this series does _not_ yet do that. Link: https://lore.kernel.org/all/20210909182525.372ee687@canb.auug.org.au/ Link: https://lore.kernel.org/lkml/CAK7LNASs6dvU6D3jL2GG3jW58fXfaj6VNOe55NJnTB8UPuk2pA@mail.gmail.com/ Link: https://github.com/ClangBuiltLinux/linux/issues/1438 * emailed patches from Nick Desaulniers : Drop some straggling mentions of gcc-4.9 as being stale compiler_attributes.h: drop __has_attribute() support for gcc4 vmlinux.lds.h: remove old check for GCC 4.9 compiler-gcc.h: drop checks for older GCC versions Makefile: drop GCC < 5 -fno-var-tracking-assignments workaround arm64: remove GCC version check for ARCH_SUPPORTS_INT128 powerpc: remove GCC version check for UPD_CONSTR riscv: remove Kconfig check for GCC version for ARCH_RV64I Kconfig.debug: drop GCC 5+ version check for DWARF5 mm/ksm: remove old GCC 4.9+ check compiler.h: drop fallback overflow checkers Documentation: raise minimum supported version of GCC to 5.1

Drop some straggling mentions of gcc-4.9 as being stale

2021-09-13T17:29:44Z

Fix up the admin-guide README file to the new gcc-5.1 requirement, and remove a stale comment about gcc support for the __assume_aligned__ attribute. Signed-off-by: Linus Torvalds

compiler_attributes.h: drop __has_attribute() support for gcc4

2021-09-13T17:20:01Z

Now that GCC 5.1 is the minimally supported default, the manual workaround for older gcc versions not having __has_attribute() are no longer relevant and can be removed. Signed-off-by: Linus Torvalds

Merge tag 'compiler-attributes-for-linus-v5.15-rc1-v2' of git://github.com/ojeda/linux

2021-09-12T23:09:26Z

Pull compiler attributes updates from Miguel Ojeda: - Fix __has_attribute(__no_sanitize_coverage__) for GCC 4 (Marco Elver) - Add Nick as Reviewer for compiler_attributes.h (Nick Desaulniers) - Move __compiletime_{error|warning} (Nick Desaulniers) * tag 'compiler-attributes-for-linus-v5.15-rc1-v2' of git://github.com/ojeda/linux: compiler_attributes.h: move __compiletime_{error|warning} MAINTAINERS: add Nick as Reviewer for compiler_attributes.h Compiler Attributes: fix __has_attribute(__no_sanitize_coverage__) for GCC 4

compiler_attributes.h: move __compiletime_{error|warning}

2021-09-08T23:14:28Z

Clang 14 will add support for __attribute__((__error__(""))) and __attribute__((__warning__(""))). To make use of these in __compiletime_error and __compiletime_warning (as used by BUILD_BUG and friends) for newer clang and detect/fallback for older versions of clang, move these to compiler_attributes.h and guard them with __has_attribute preprocessor guards. Link: https://reviews.llvm.org/D106030 Link: https://bugs.llvm.org/show_bug.cgi?id=16428 Link: https://github.com/ClangBuiltLinux/linux/issues/1173 Signed-off-by: Nick Desaulniers Reviewed-by: Nathan Chancellor Reviewed-by: Kees Cook [Reworded, landed in Clang 14] Signed-off-by: Miguel Ojeda

Compiler Attributes: fix __has_attribute(__no_sanitize_coverage__) for GCC 4

2021-07-15T23:06:44Z

Fix __has_attribute(__no_sanitize_coverage__) for GCC 4 by defining __GCC4_has_attribute___no_sanitize_coverage__. Fixes: 540540d06e9d ("kcov: add __no_sanitize_coverage to fix noinstr for all architectures") Reported-by: Geert Uytterhoeven Signed-off-by: Marco Elver Signed-off-by: Miguel Ojeda