__do_page_fault() is over complicated with multiple goto statements. This cleans up code flow and while there drops the vm_fault_t argument.
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]> --- arch/arm64/mm/fault.c | 38 ++++++++++++++++---------------------- 1 file changed, 16 insertions(+), 22 deletions(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 170c71f..a53a30e 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -397,37 +397,31 @@ 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. + * Check if the VMA has got the required permssion with respect + * to the access fault here. */ -good_area: + if (!(vma->vm_flags & vm_flags)) + return VM_FAULT_BADACCESS; + /* - * Check that the permissions on the VMA allow for the fault which - * occurred. + * There is a valid VMA for this access. But before proceeding + * make sure that it has required flags if there is an attempt + * to expand the stack downwards. */ - if (!(vma->vm_flags & vm_flags)) { - fault = VM_FAULT_BADACCESS; - goto out; - } + 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; + } 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
