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instrumented.h: add instrument_memcpy_before, instrument_memcpy_after

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Bug detection tools based on compiler instrumentation may miss memory
accesses in custom memcpy implementations (such as copy_mc_to_kernel). 
Provide instrumentation hooks that tell KASAN, KCSAN, and KMSAN about such
accesses.

Link: https://lore.kernel.org/all/3b7dbd88-0861-4638-b2d2-911c97a4cadf@I-love.SAKURA.ne.jp/
Link: https://lkml.kernel.org/r/20240320101851.2589698-2-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Alexander Potapenko 2024-03-20 11:18:50 +01:00 committed by Andrew Morton
parent 3429055f04
commit 922621a682
1 changed files with 35 additions and 0 deletions
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35
include/linux/instrumented.h
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@ -147,6 +147,41 @@ instrument_copy_from_user_after(const void *to, const void __user *from,
kmsan_unpoison_memory(to, n - left);
}
/**
* instrument_memcpy_before - add instrumentation before non-instrumented memcpy
* @to: destination address
* @from: source address
* @n: number of bytes to copy
*
* Instrument memory accesses that happen in custom memcpy implementations. The
* instrumentation should be inserted before the memcpy call.
*/
static __always_inline void instrument_memcpy_before(void *to, const void *from,
unsigned long n)
{
kasan_check_write(to, n);
kasan_check_read(from, n);
kcsan_check_write(to, n);
kcsan_check_read(from, n);
}
/**
* instrument_memcpy_after - add instrumentation after non-instrumented memcpy
* @to: destination address
* @from: source address
* @n: number of bytes to copy
* @left: number of bytes not copied (if known)
*
* Instrument memory accesses that happen in custom memcpy implementations. The
* instrumentation should be inserted after the memcpy call.
*/
static __always_inline void instrument_memcpy_after(void *to, const void *from,
unsigned long n,
unsigned long left)
{
kmsan_memmove(to, from, n - left);
}
/**
* instrument_get_user() - add instrumentation to get_user()-like macros
* @to: destination variable, may not be address-taken