mn10300: prevent double syscall restarts

set ->orig_d0 to -1, same as what sigreturn does

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 3 deletions

diff --git a/arch/mn10300/kernel/signal.c b/arch/mn10300/kernel/signal.c
index 57178a8d5af0..4ef99256fa49 100644
--- a/arch/mn10300/kernel/signal.c
+++ b/arch/mn10300/kernel/signal.c
@@ -432,6 +432,12 @@ give_sigsegv:
         return -EFAULT;
 }
 
+static inline void stepback(struct pt_regs *regs)
+{
+        regs->pc -= 2;
+        regs->orig_d0 = -1;
+}
+
 /*
  * handle the actual delivery of a signal to userspace
  */
@@ -459,7 +465,7 @@ static int handle_signal(int sig,
                         /* fallthrough */
                 case -ERESTARTNOINTR:
                         regs->d0 = regs->orig_d0;
-                        regs->pc -= 2;
+                        stepback(regs);
                 }
         }
 
@@ -527,12 +533,12 @@ static void do_signal(struct pt_regs *regs)
                 case -ERESTARTSYS:
                 case -ERESTARTNOINTR:
                         regs->d0 = regs->orig_d0;
-                        regs->pc -= 2;
+                        stepback(regs);
                         break;
 
                 case -ERESTART_RESTARTBLOCK:
                         regs->d0 = __NR_restart_syscall;
-                        regs->pc -= 2;
+                        stepback(regs);
                         break;
                 }
         }