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linux-stable-mirror/include/linux/compiler-clang.h
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Alexander PotapenkoandGreg Kroah-Hartman 02824743be kmsan: introduce __no_sanitize_memory and __no_kmsan_checks
[ Upstream commit 9b448bc25b ]

__no_sanitize_memory is a function attribute that instructs KMSAN to skip
a function during instrumentation.  This is needed to e.g.  implement the
noinstr functions.

__no_kmsan_checks is a function attribute that makes KMSAN ignore the
uninitialized values coming from the function's inputs, and initialize the
function's outputs.

Functions marked with this attribute can't be inlined into functions not
marked with it, and vice versa.  This behavior is overridden by
__always_inline.

__SANITIZE_MEMORY__ is a macro that's defined iff the file is instrumented
with KMSAN.  This is not the same as CONFIG_KMSAN, which is defined for
every file.

Link: https://lkml.kernel.org/r/20220915150417.722975-8-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: ced37e9cea ("x86/dumpstack: Prevent KASAN false positive warnings in __show_regs()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:11:28 +01:00

129 lines
4.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_COMPILER_TYPES_H
#error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead."
#endif
#define CLANG_VERSION (__clang_major__ * 10000 \
+ __clang_minor__ * 100 \
+ __clang_patchlevel__)
#if CLANG_VERSION < 100001
#ifndef __BPF_TRACING__
# error Sorry, your version of Clang is too old - please use 10.0.1 or newer.
#endif
#endif
/* Compiler specific definitions for Clang compiler */
/*
* Clang prior to 17 is being silly and considers many __cleanup() variables
* as unused (because they are, their sole purpose is to go out of scope).
*
* https://reviews.llvm.org/D152180
*/
#undef __cleanup
#define __cleanup(func) __maybe_unused __attribute__((__cleanup__(func)))
/* same as gcc, this was present in clang-2.6 so we can assume it works
* with any version that can compile the kernel
*/
#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
/* all clang versions usable with the kernel support KASAN ABI version 5 */
#define KASAN_ABI_VERSION 5
/*
* Clang 22 added preprocessor macros to match GCC, in hopes of eventually
* dropping __has_feature support for sanitizers:
* https://github.com/llvm/llvm-project/commit/568c23bbd3303518c5056d7f03444dae4fdc8a9c
* Create these macros for older versions of clang so that it is easy to clean
* up once the minimum supported version of LLVM for building the kernel always
* creates these macros.
*
* Note: Checking __has_feature(*_sanitizer) is only true if the feature is
* enabled. Therefore it is not required to additionally check defined(CONFIG_*)
* to avoid adding redundant attributes in other configurations.
*/
#if __has_feature(address_sanitizer) && !defined(__SANITIZE_ADDRESS__)
#define __SANITIZE_ADDRESS__
#endif
#if __has_feature(hwaddress_sanitizer) && !defined(__SANITIZE_HWADDRESS__)
#define __SANITIZE_HWADDRESS__
#endif
#if __has_feature(thread_sanitizer) && !defined(__SANITIZE_THREAD__)
#define __SANITIZE_THREAD__
#endif
/*
* Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel.
*/
#ifdef __SANITIZE_HWADDRESS__
#define __SANITIZE_ADDRESS__
#endif
#ifdef __SANITIZE_ADDRESS__
#define __no_sanitize_address \
__attribute__((no_sanitize("address", "hwaddress")))
#else
#define __no_sanitize_address
#endif
#ifdef __SANITIZE_THREAD__
#define __no_sanitize_thread \
__attribute__((no_sanitize("thread")))
#else
#define __no_sanitize_thread
#endif
#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
#define __HAVE_BUILTIN_BSWAP32__
#define __HAVE_BUILTIN_BSWAP64__
#define __HAVE_BUILTIN_BSWAP16__
#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
#if __has_feature(undefined_behavior_sanitizer)
/* GCC does not have __SANITIZE_UNDEFINED__ */
#define __no_sanitize_undefined \
__attribute__((no_sanitize("undefined")))
#else
#define __no_sanitize_undefined
#endif
#if __has_feature(memory_sanitizer)
#define __SANITIZE_MEMORY__
/*
* Unlike other sanitizers, KMSAN still inserts code into functions marked with
* no_sanitize("kernel-memory"). Using disable_sanitizer_instrumentation
* provides the behavior consistent with other __no_sanitize_ attributes,
* guaranteeing that __no_sanitize_memory functions remain uninstrumented.
*/
#define __no_sanitize_memory __disable_sanitizer_instrumentation
/*
* The __no_kmsan_checks attribute ensures that a function does not produce
* false positive reports by:
* - initializing all local variables and memory stores in this function;
* - skipping all shadow checks;
* - passing initialized arguments to this function's callees.
*/
#define __no_kmsan_checks __attribute__((no_sanitize("kernel-memory")))
#else
#define __no_sanitize_memory
#define __no_kmsan_checks
#endif
/*
* Support for __has_feature(coverage_sanitizer) was added in Clang 13 together
* with no_sanitize("coverage"). Prior versions of Clang support coverage
* instrumentation, but cannot be queried for support by the preprocessor.
*/
#if __has_feature(coverage_sanitizer)
#define __no_sanitize_coverage __attribute__((no_sanitize("coverage")))
#else
#define __no_sanitize_coverage
#endif
#if __has_feature(shadow_call_stack)
# define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
#endif