s390/mm: make page faults killable

This is the s390 variant of 37b23e05 "x86,mm: make pagefault killable".

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 6a12d1bb6e09..2a34a1c35a7c 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -49,6 +49,7 @@
 #define VM_FAULT_BADCONTEXT     0x010000
 #define VM_FAULT_BADMAP         0x020000
 #define VM_FAULT_BADACCESS      0x040000
+#define VM_FAULT_SIGNAL 0x080000
 
 static unsigned long store_indication;
 
@@ -229,6 +230,10 @@ static noinline void do_fault_error(struct pt_regs *regs, int fault)
         case VM_FAULT_BADCONTEXT:
                 do_no_context(regs);
                 break;
+        case VM_FAULT_SIGNAL:
+                if (!user_mode(regs))
+                        do_no_context(regs);
+                break;
         default: /* fault & VM_FAULT_ERROR */
                 if (fault & VM_FAULT_OOM) {
                         if (!(regs->psw.mask & PSW_MASK_PSTATE))
@@ -286,7 +291,7 @@ static inline int do_exception(struct pt_regs *regs, int access)
 
         address = trans_exc_code & __FAIL_ADDR_MASK;
         perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
-        flags = FAULT_FLAG_ALLOW_RETRY;
+        flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
         if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400)
                 flags |= FAULT_FLAG_WRITE;
         down_read(&mm->mmap_sem);
@@ -335,6 +340,11 @@ retry:
          * the fault.
          */
         fault = handle_mm_fault(mm, vma, address, flags);
+        /* No reason to continue if interrupted by SIGKILL. */
+        if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) {
+                fault = VM_FAULT_SIGNAL;
+                goto out;
+        }
         if (unlikely(fault & VM_FAULT_ERROR))
                 goto out_up;