[PATCH] arm64: mm: pass original fault address to handle_mm_fault() in PER_VMA_LOCK block

From: Jisheng Zhang
Date: Wed May 24 2023 - 09:24:48 EST

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

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:

perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, ..., addr) // orig addr
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@xxxxxxxxxx>
arch/arm64/mm/fault.c | 3 +--
1 file changed, 1 insertion(+), 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,
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);

if (!(fault & VM_FAULT_RETRY)) {