#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;
* 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))
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;
#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
*/
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,
* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk of
* starvation.
*/
- flags &= ~FAULT_FLAG_ALLOW_RETRY;
+ mm_flags &= ~FAULT_FLAG_ALLOW_RETRY;
goto retry;
}
}
return 0;
}
-/*
- * Some section permission faults need to be handled gracefully. They can
- * happen due to a __{get,put}_user during an oops.
- */
-static int do_sect_fault(unsigned long addr, unsigned int esr,
- struct pt_regs *regs)
-{
- do_bad_area(addr, esr, regs);
- return 0;
-}
-
/*
* This abort handler always returns "fault".
*/
{ do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" },
{ do_page_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" },
{ do_bad, SIGBUS, 0, "reserved access flag fault" },
- { do_bad, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
- { do_bad, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" },
{ do_bad, SIGBUS, 0, "reserved permission fault" },
- { do_bad, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
- { do_sect_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
{ do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" },
{ do_bad, SIGBUS, 0, "synchronous external abort" },
{ do_bad, SIGBUS, 0, "asynchronous external abort" },