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| author | Wang Kefeng <wangkefeng.wang@huawei.com> | 2021-09-22 14:56:29 +0100 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2021-10-19 10:35:06 +0100 |
| commit | f177b06ed7d56c1d8256769d1a6e1feec90153dc (patch) | |
| tree | 1e35d3344712db611cd58640895b637fac12195b /arch/arm/mm | |
| parent | 488cab12c37169687015fbdfa8be7b0da42f3146 (diff) | |
| download | linux-f177b06ed7d56c1d8256769d1a6e1feec90153dc.tar.bz2 | |
ARM: 9127/1: mm: Cleanup access_error()
Now the write fault check in do_page_fault() and access_error() twice,
we can cleanup access_error(), and make the fault check and vma flags set
into do_page_fault() directly, then pass the vma flags to __do_page_fault.
No functional change.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/mm')
| -rw-r--r-- | arch/arm/mm/fault.c | 38 |
1 files changed, 14 insertions, 24 deletions
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 249db395bdf0..9a6d74f6ea1d 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -183,26 +183,9 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs) #define VM_FAULT_BADMAP 0x010000 #define VM_FAULT_BADACCESS 0x020000 -/* - * Check that the permissions on the VMA allow for the fault which occurred. - * If we encountered a write fault, we must have write permission, otherwise - * we allow any permission. - */ -static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) -{ - unsigned int mask = VM_ACCESS_FLAGS; - - if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) - mask = VM_WRITE; - if (fsr & FSR_LNX_PF) - mask = VM_EXEC; - - return vma->vm_flags & mask ? false : true; -} - static vm_fault_t __kprobes -__do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, - unsigned int flags, struct pt_regs *regs) +__do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int flags, + unsigned long vma_flags, struct pt_regs *regs) { struct vm_area_struct *vma = find_vma(mm, addr); if (unlikely(!vma)) @@ -218,10 +201,10 @@ __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, } /* - * Ok, we have a good vm_area for this - * memory access, so we can handle it. + * ok, we have a good vm_area for this memory access, check the + * permissions on the VMA allow for the fault which occurred. */ - if (access_error(fsr, vma)) + if (!(vma->vm_flags & vma_flags)) return VM_FAULT_BADACCESS; return handle_mm_fault(vma, addr & PAGE_MASK, flags, regs); @@ -234,6 +217,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) int sig, code; vm_fault_t fault; unsigned int flags = FAULT_FLAG_DEFAULT; + unsigned long vm_flags = VM_ACCESS_FLAGS; if (kprobe_page_fault(regs, fsr)) return 0; @@ -252,8 +236,14 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (user_mode(regs)) flags |= FAULT_FLAG_USER; - if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) + + if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) { flags |= FAULT_FLAG_WRITE; + vm_flags = VM_WRITE; + } + + if (fsr & FSR_LNX_PF) + vm_flags = VM_EXEC; perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); @@ -281,7 +271,7 @@ retry: #endif } - fault = __do_page_fault(mm, addr, fsr, flags, regs); + fault = __do_page_fault(mm, addr, flags, vm_flags, regs); /* If we need to retry but a fatal signal is pending, handle the * signal first. We do not need to release the mmap_lock because |