diff options
author | Jisheng Zhang <jszhang@kernel.org> | 2023-05-24 16:13:05 +0300 |
---|---|---|
committer | Will Deacon <will@kernel.org> | 2023-06-02 15:02:44 +0300 |
commit | 0e2aba694866b451db0932a6706683c48379134c (patch) | |
tree | 612439df6266a8b243b47f7f8212b97357cbc45d /arch/arm64/mm | |
parent | f3c3762178fad5cf5dc108fb061ba010818323b4 (diff) | |
download | linux-0e2aba694866b451db0932a6706683c48379134c.tar.xz |
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>
Diffstat (limited to 'arch/arm64/mm')
-rw-r--r-- | arch/arm64/mm/fault.c | 3 |
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)) { |