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author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-02-19 07:51:35 +0100 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-02-19 07:51:35 +0100 |
commit | 07749061b837a1268146dc8a620a522253cea877 (patch) | |
tree | 3708ac3f1a088869daf7e9826bc4b56abfcdac74 /arch/x86/include/asm/kmsan.h | |
parent | 5c0941c55e5f681ffb05f395222ac673460bb3d0 (diff) | |
parent | b401b621758e46812da61fa58a67c3fd8d91de0d (diff) | |
download | linux-stable-07749061b837a1268146dc8a620a522253cea877.tar.gz linux-stable-07749061b837a1268146dc8a620a522253cea877.tar.bz2 linux-stable-07749061b837a1268146dc8a620a522253cea877.zip |
Merge 6.8-rc5 into driver-core-next
We need the driver core changes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/include/asm/kmsan.h')
-rw-r--r-- | arch/x86/include/asm/kmsan.h | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/x86/include/asm/kmsan.h b/arch/x86/include/asm/kmsan.h index 8fa6ac0e2d76..d91b37f5b4bb 100644 --- a/arch/x86/include/asm/kmsan.h +++ b/arch/x86/include/asm/kmsan.h @@ -64,6 +64,7 @@ static inline bool kmsan_virt_addr_valid(void *addr) { unsigned long x = (unsigned long)addr; unsigned long y = x - __START_KERNEL_map; + bool ret; /* use the carry flag to determine if x was < __START_KERNEL_map */ if (unlikely(x > y)) { @@ -79,7 +80,21 @@ static inline bool kmsan_virt_addr_valid(void *addr) return false; } - return pfn_valid(x >> PAGE_SHIFT); + /* + * pfn_valid() relies on RCU, and may call into the scheduler on exiting + * the critical section. However, this would result in recursion with + * KMSAN. Therefore, disable preemption here, and re-enable preemption + * below while suppressing reschedules to avoid recursion. + * + * Note, this sacrifices occasionally breaking scheduling guarantees. + * Although, a kernel compiled with KMSAN has already given up on any + * performance guarantees due to being heavily instrumented. + */ + preempt_disable(); + ret = pfn_valid(x >> PAGE_SHIFT); + preempt_enable_no_resched(); + + return ret; } #endif /* !MODULE */ |