The access_[pkey]_error() of vma 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_access_pkey()/bad_access(), 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.
Signed-off-by: Kefeng Wang <wangkefeng.w...@huawei.com>
---
arch/powerpc/mm/fault.c | 33 ++++++++++++++++++++-------------
1 file changed, 20 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 53335ae21a40..215690452495 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -71,23 +71,26 @@ static noinline int bad_area_nosemaphore(struct pt_regs
*regs, unsigned long add
return __bad_area_nosemaphore(regs, address, SEGV_MAPERR);
}
-static int __bad_area(struct pt_regs *regs, unsigned long address, int si_code)
+static int __bad_area(struct pt_regs *regs, unsigned long address, int si_code,
+ struct mm_struct *mm, struct vm_area_struct *vma)
{
- 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);
return __bad_area_nosemaphore(regs, address, si_code);
}
static noinline int bad_access_pkey(struct pt_regs *regs, unsigned long
address,
+ struct mm_struct *mm,
struct vm_area_struct *vma)
{
- struct mm_struct *mm = current->mm;
int pkey;
/*
@@ -109,7 +112,10 @@ static noinline int bad_access_pkey(struct pt_regs *regs,
unsigned long address,
*/
pkey = vma_pkey(vma);
- mmap_read_unlock(mm);
+ if (mm)
+ mmap_read_unlock(mm);
+ else
+ vma_end_read(vma);
/*
* If we are in kernel mode, bail out with a SEGV, this will
@@ -124,9 +130,10 @@ static noinline int bad_access_pkey(struct pt_regs *regs,
unsigned long address,
return 0;
}
-static noinline int bad_access(struct pt_regs *regs, unsigned long address)
+static noinline int bad_access(struct pt_regs *regs, unsigned long address,
+ struct mm_struct *mm, struct vm_area_struct *vma)
{
- return __bad_area(regs, address, SEGV_ACCERR);
+ return __bad_area(regs, address, SEGV_ACCERR, mm, vma);
}
static int do_sigbus(struct pt_regs *regs, unsigned long address,
@@ -479,13 +486,13 @@ static int ___do_page_fault(struct pt_regs *regs,
unsigned long address,
if (unlikely(access_pkey_error(is_write, is_exec,
(error_code & DSISR_KEYFAULT), vma))) {
- vma_end_read(vma);
- goto lock_mmap;
+ count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
+ return bad_access_pkey(regs, address, NULL, vma);
}
if (unlikely(access_error(is_write, is_exec, vma))) {
- vma_end_read(vma);
- goto lock_mmap;
+ count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
+ return bad_access(regs, address, NULL, vma);
}
fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK,
regs);
@@ -521,10 +528,10 @@ static int ___do_page_fault(struct pt_regs *regs,
unsigned long address,
if (unlikely(access_pkey_error(is_write, is_exec,
(error_code & DSISR_KEYFAULT), vma)))
- return bad_access_pkey(regs, address, vma);
+ return bad_access_pkey(regs, address, mm, vma);
if (unlikely(access_error(is_write, is_exec, vma)))
- return bad_access(regs, address);
+ return bad_access(regs, address, mm, vma);
/*
* If for any reason at all we couldn't handle the fault,
--
2.27.0
