| Message ID | 1559898786-28530-3-git-send-email-anshuman.khandual@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64/mm: Clean ups for do_page_fault() | expand |
On Fri, Jun 07, 2019 at 02:43:06PM +0530, Anshuman Khandual wrote: > __do_page_fault() is over complicated with multiple goto statements. This > cleans up the code flow and while there drops local variable vm_fault_t. > > Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: James Morse <james.morse@arm.com> > Cc: Andrey Konovalov <andreyknvl@google.com> > Cc: Christoph Hellwig <hch@infradead.org> This keeps the existing behaviour, and is certainly cleaner, so: Reviewed-by: Mark Rutland <Mark.rutland@arm.com> Mark. > --- > arch/arm64/mm/fault.c | 30 +++++++++++------------------- > 1 file changed, 11 insertions(+), 19 deletions(-) > > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index 95cac4a..235b7c0 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -397,37 +397,29 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re > static vm_fault_t __do_page_fault(struct mm_struct *mm, unsigned long addr, > unsigned int mm_flags, unsigned long vm_flags) > { > - struct vm_area_struct *vma; > - vm_fault_t fault; > + struct vm_area_struct *vma = find_vma(mm, addr); > > - vma = find_vma(mm, addr); > - fault = VM_FAULT_BADMAP; > if (unlikely(!vma)) > - goto out; > - if (unlikely(vma->vm_start > addr)) > - goto check_stack; > + return VM_FAULT_BADMAP; > > /* > * Ok, we have a good vm_area for this memory access, so we can handle > * it. > */ > -good_area: > + if (unlikely(vma->vm_start > addr)) { > + if (!(vma->vm_flags & VM_GROWSDOWN)) > + return VM_FAULT_BADMAP; > + if (expand_stack(vma, addr)) > + return VM_FAULT_BADMAP; > + } > + > /* > * Check that the permissions on the VMA allow for the fault which > * occurred. > */ > - if (!(vma->vm_flags & vm_flags)) { > - fault = VM_FAULT_BADACCESS; > - goto out; > - } > - > + if (!(vma->vm_flags & vm_flags)) > + return VM_FAULT_BADACCESS; > return handle_mm_fault(vma, addr & PAGE_MASK, mm_flags); > - > -check_stack: > - if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) > - goto good_area; > -out: > - return fault; > } > > static bool is_el0_instruction_abort(unsigned int esr) > -- > 2.7.4 >
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 95cac4a..235b7c0 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -397,37 +397,29 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re static vm_fault_t __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int mm_flags, unsigned long vm_flags) { - struct vm_area_struct *vma; - vm_fault_t fault; + struct vm_area_struct *vma = find_vma(mm, addr); - vma = find_vma(mm, addr); - fault = VM_FAULT_BADMAP; if (unlikely(!vma)) - goto out; - if (unlikely(vma->vm_start > addr)) - goto check_stack; + return VM_FAULT_BADMAP; /* * Ok, we have a good vm_area for this memory access, so we can handle * it. */ -good_area: + if (unlikely(vma->vm_start > addr)) { + if (!(vma->vm_flags & VM_GROWSDOWN)) + return VM_FAULT_BADMAP; + if (expand_stack(vma, addr)) + return VM_FAULT_BADMAP; + } + /* * Check that the permissions on the VMA allow for the fault which * occurred. */ - if (!(vma->vm_flags & vm_flags)) { - fault = VM_FAULT_BADACCESS; - goto out; - } - + if (!(vma->vm_flags & vm_flags)) + return VM_FAULT_BADACCESS; return handle_mm_fault(vma, addr & PAGE_MASK, mm_flags); - -check_stack: - if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr)) - goto good_area; -out: - return fault; } static bool is_el0_instruction_abort(unsigned int esr)
__do_page_fault() is over complicated with multiple goto statements. This cleans up the code flow and while there drops local variable vm_fault_t. Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Christoph Hellwig <hch@infradead.org> --- arch/arm64/mm/fault.c | 30 +++++++++++------------------- 1 file changed, 11 insertions(+), 19 deletions(-)