Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Wed, 11 Jan 2023 11:18:06 +0100 | Subject | [PATCH] Revert "x86: kmsan: sync metadata pages on page fault" | From | Alexander Potapenko <> |
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This reverts commit 3f1e2c7a9099c1ed32c67f12cdf432ba782cf51f.
As noticed by Qun-Wei Lin, arch_sync_kernel_mappings() in arch/x86/mm/fault.c is only used with CONFIG_X86_32, whereas KMSAN is only supported on x86_64, where this code is not compiled.
The patch in question dates back to downstream KMSAN branch based on v5.8-rc5, it sneaked into upstream unnoticed in v6.1.
Reported-by: Qun-Wei Lin <qun-wei.lin@mediatek.com> Link: https://github.com/google/kmsan/issues/91 Signed-off-by: Alexander Potapenko <glider@google.com> --- arch/x86/mm/fault.c | 23 +---------------------- 1 file changed, 1 insertion(+), 22 deletions(-)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 7b0d4ab894c8b..a498ae1fbe665 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -260,7 +260,7 @@ static noinline int vmalloc_fault(unsigned long address) } NOKPROBE_SYMBOL(vmalloc_fault); -static void __arch_sync_kernel_mappings(unsigned long start, unsigned long end) +void arch_sync_kernel_mappings(unsigned long start, unsigned long end) { unsigned long addr; @@ -284,27 +284,6 @@ static void __arch_sync_kernel_mappings(unsigned long start, unsigned long end) } } -void arch_sync_kernel_mappings(unsigned long start, unsigned long end) -{ - __arch_sync_kernel_mappings(start, end); -#ifdef CONFIG_KMSAN - /* - * KMSAN maintains two additional metadata page mappings for the - * [VMALLOC_START, VMALLOC_END) range. These mappings start at - * KMSAN_VMALLOC_SHADOW_START and KMSAN_VMALLOC_ORIGIN_START and - * have to be synced together with the vmalloc memory mapping. - */ - if (start >= VMALLOC_START && end < VMALLOC_END) { - __arch_sync_kernel_mappings( - start - VMALLOC_START + KMSAN_VMALLOC_SHADOW_START, - end - VMALLOC_START + KMSAN_VMALLOC_SHADOW_START); - __arch_sync_kernel_mappings( - start - VMALLOC_START + KMSAN_VMALLOC_ORIGIN_START, - end - VMALLOC_START + KMSAN_VMALLOC_ORIGIN_START); - } -#endif -} - static bool low_pfn(unsigned long pfn) { return pfn < max_low_pfn; -- 2.39.0.314.g84b9a713c41-goog
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