diff options
| author | Kefeng Wang <wangkefeng.wang@huawei.com> | 2024-04-03 11:38:05 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-04-26 06:56:40 +0300 |
| commit | bc7996c864bf58102f640474e04ec5ab04911ac1 (patch) | |
| tree | 8b9abd63dbf484f69e3330a733829b33ae6d306e | |
| parent | 82b7a618397c80736506c05d9add4aaea91297e8 (diff) | |
| download | linux-bc7996c864bf58102f640474e04ec5ab04911ac1.tar.xz | |
x86: mm: accelerate pagefault when badaccess
The access_error() of vma is already checked under per-VMA lock, if it is
a bad access, directly handle error, no need to retry with mmap_lock
again. In order to release the correct lock, pass the mm_struct into
bad_area_access_error(). If mm is NULL, release vma lock, or release
mmap_lock. Since the page faut is handled under per-VMA lock, count it as
a vma lock event with VMA_LOCK_SUCCESS.
Link: https://lkml.kernel.org/r/20240403083805.1818160-8-wangkefeng.wang@huawei.com
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | arch/x86/mm/fault.c | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index a4cc20d0036d..67b18adc75dd 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -866,14 +866,17 @@ bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code, static void __bad_area(struct pt_regs *regs, unsigned long error_code, - unsigned long address, u32 pkey, int si_code) + unsigned long address, struct mm_struct *mm, + struct vm_area_struct *vma, u32 pkey, int si_code) { - struct mm_struct *mm = current->mm; /* * Something tried to access memory that isn't in our memory map.. * Fix it, but check if it's kernel or user first.. */ - mmap_read_unlock(mm); + if (mm) + mmap_read_unlock(mm); + else + vma_end_read(vma); __bad_area_nosemaphore(regs, error_code, address, pkey, si_code); } @@ -897,7 +900,8 @@ static inline bool bad_area_access_from_pkeys(unsigned long error_code, static noinline void bad_area_access_error(struct pt_regs *regs, unsigned long error_code, - unsigned long address, struct vm_area_struct *vma) + unsigned long address, struct mm_struct *mm, + struct vm_area_struct *vma) { /* * This OSPKE check is not strictly necessary at runtime. @@ -927,9 +931,9 @@ bad_area_access_error(struct pt_regs *regs, unsigned long error_code, */ u32 pkey = vma_pkey(vma); - __bad_area(regs, error_code, address, pkey, SEGV_PKUERR); + __bad_area(regs, error_code, address, mm, vma, pkey, SEGV_PKUERR); } else { - __bad_area(regs, error_code, address, 0, SEGV_ACCERR); + __bad_area(regs, error_code, address, mm, vma, 0, SEGV_ACCERR); } } @@ -1357,8 +1361,9 @@ void do_user_addr_fault(struct pt_regs *regs, goto lock_mmap; if (unlikely(access_error(error_code, vma))) { - vma_end_read(vma); - goto lock_mmap; + bad_area_access_error(regs, error_code, address, NULL, vma); + count_vm_vma_lock_event(VMA_LOCK_SUCCESS); + return; } fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK, regs); if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED))) @@ -1394,7 +1399,7 @@ retry: * we can handle it.. */ if (unlikely(access_error(error_code, vma))) { - bad_area_access_error(regs, error_code, address, vma); + bad_area_access_error(regs, error_code, address, mm, vma); return; } |