1 files changed, 20 insertions, 26 deletions

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 0ecac8980aae..6c8ba25bf6bb 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -152,25 +152,8 @@ void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
 #define ESR_CM                  (1 << 8)
 #define ESR_LNX_EXEC            (1 << 24)
 
-/*
- * 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 esr, struct vm_area_struct *vma)
-{
-        unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
-
-        if (esr & ESR_WRITE)
-                mask = VM_WRITE;
-        if (esr & ESR_LNX_EXEC)
-                mask = VM_EXEC;
-
-        return vma->vm_flags & mask ? false : true;
-}
-
 static int __do_page_fault(struct mm_struct *mm, unsigned long addr,
-                           unsigned int esr, unsigned int flags,
+                           unsigned int mm_flags, unsigned long vm_flags,
                            struct task_struct *tsk)
 {
         struct vm_area_struct *vma;
@@ -188,12 +171,17 @@ static int __do_page_fault(struct mm_struct *mm, unsigned long addr,
          * it.
          */
 good_area:
-        if (access_error(esr, vma)) {
+        /*
+         * Check that the permissions on the VMA allow for the fault which
+         * occurred. If we encountered a write or exec fault, we must have
+         * appropriate permissions, otherwise we allow any permission.
+         */
+        if (!(vma->vm_flags & vm_flags)) {
                 fault = VM_FAULT_BADACCESS;
                 goto out;
         }
 
-        return handle_mm_fault(mm, vma, addr & PAGE_MASK, flags);
+        return handle_mm_fault(mm, vma, addr & PAGE_MASK, mm_flags);
 
 check_stack:
         if (vma->vm_flags & VM_GROWSDOWN && !expand_stack(vma, addr))
@@ -208,9 +196,15 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
         struct task_struct *tsk;
         struct mm_struct *mm;
         int fault, sig, code;
-        bool write = (esr & ESR_WRITE) && !(esr & ESR_CM);
-        unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
-                (write ? FAULT_FLAG_WRITE : 0);
+        unsigned long vm_flags = VM_READ | VM_WRITE | VM_EXEC;
+        unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+
+        if (esr & ESR_LNX_EXEC) {
+                vm_flags = VM_EXEC;
+        } else if ((esr & ESR_WRITE) && !(esr & ESR_CM)) {
+                vm_flags = VM_WRITE;
+                mm_flags |= FAULT_FLAG_WRITE;
+        }
 
         tsk = current;
         mm  = tsk->mm;
@@ -248,7 +242,7 @@ retry:
 #endif
         }
 
-        fault = __do_page_fault(mm, addr, esr, flags, tsk);
+        fault = __do_page_fault(mm, addr, mm_flags, vm_flags, tsk);
 
         /*
          * If we need to retry but a fatal signal is pending, handle the
@@ -265,7 +259,7 @@ retry:
          */
 
         perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
-        if (flags & FAULT_FLAG_ALLOW_RETRY) {
+        if (mm_flags & FAULT_FLAG_ALLOW_RETRY) {
                 if (fault & VM_FAULT_MAJOR) {
                         tsk->maj_flt++;
                         perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
@@ -280,7 +274,7 @@ retry:
                          * Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of
                          * starvation.
                          */
-                        flags &= ~FAULT_FLAG_ALLOW_RETRY;
+                        mm_flags &= ~FAULT_FLAG_ALLOW_RETRY;
                         goto retry;
                 }
         }