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 <[email protected]> > Cc: Catalin Marinas <[email protected]> > Cc: Will Deacon <[email protected]> > Cc: Mark Rutland <[email protected]> > Cc: James Morse <[email protected]> > Cc: Andrey Konovalov <[email protected]> > Cc: Christoph Hellwig <[email protected]>
This keeps the existing behaviour, and is certainly cleaner, so: Reviewed-by: Mark Rutland <[email protected]> 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 >
