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authorJisheng Zhang <jszhang@kernel.org>2023-05-24 21:13:05 +0800
committerWill Deacon <will@kernel.org>2023-06-02 13:02:44 +0100
commit0e2aba694866b451db0932a6706683c48379134c (patch)
tree612439df6266a8b243b47f7f8212b97357cbc45d
parentf3c3762178fad5cf5dc108fb061ba010818323b4 (diff)
arm64: mm: pass original fault address to handle_mm_fault() in PER_VMA_LOCK block
When reading the arm64's PER_VMA_LOCK support code, I found a bit difference between arm64 and other arch when calling handle_mm_fault() during VMA lock-based page fault handling: the fault address is masked before passing to handle_mm_fault(). This is also different from the usage in mmap_lock-based handling. I think we need to pass the original fault address to handle_mm_fault() as we did in commit 84c5e23edecd ("arm64: mm: Pass original fault address to handle_mm_fault()"). If we go through the code path further, we can find that the "masked" fault address can cause mismatched fault address between perf sw major/minor page fault sw event and perf page fault sw event: do_page_fault perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, ..., addr) // orig addr handle_mm_fault mm_account_fault perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, ...) // masked addr Fixes: cd7f176aea5f ("arm64/mm: try VMA lock-based page fault handling first") Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20230524131305.2808-1-jszhang@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
-rw-r--r--arch/arm64/mm/fault.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index cb21ccd7940d..6045a5117ac1 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -600,8 +600,7 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
vma_end_read(vma);
goto lock_mmap;
}
- fault = handle_mm_fault(vma, addr & PAGE_MASK,
- mm_flags | FAULT_FLAG_VMA_LOCK, regs);
+ fault = handle_mm_fault(vma, addr, mm_flags | FAULT_FLAG_VMA_LOCK, regs);
vma_end_read(vma);
if (!(fault & VM_FAULT_RETRY)) {