1 files changed, 12 insertions, 8 deletions

diff --git a/arch/tile/kernel/signal.c b/arch/tile/kernel/signal.c
index fb28e85ae3ae..1260321155f1 100644
--- a/arch/tile/kernel/signal.c
+++ b/arch/tile/kernel/signal.c
@@ -16,7 +16,6 @@
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
-#include <linux/smp_lock.h>
 #include <linux/kernel.h>
 #include <linux/signal.h>
 #include <linux/errno.h>
@@ -53,7 +52,7 @@ SYSCALL_DEFINE3(sigaltstack, const stack_t __user *, uss,
  */
 
 int restore_sigcontext(struct pt_regs *regs,
-                       struct sigcontext __user *sc, long *pr0)
+                       struct sigcontext __user *sc)
 {
         int err = 0;
         int i;
@@ -71,19 +70,20 @@ int restore_sigcontext(struct pt_regs *regs,
         for (i = 0; i < sizeof(struct pt_regs)/sizeof(long); ++i)
                 err |= __get_user(regs->regs[i], &sc->gregs[i]);
 
+        /* Ensure that the PL is always set to USER_PL. */
+        regs->ex1 = PL_ICS_EX1(USER_PL, EX1_ICS(regs->ex1));
+
         regs->faultnum = INT_SWINT_1_SIGRETURN;
 
-        err |= __get_user(*pr0, &sc->gregs[0]);
         return err;
 }
 
-/* sigreturn() returns long since it restores r0 in the interrupted code. */
+/* The assembly shim for this function arranges to ignore the return value. */
 SYSCALL_DEFINE1(rt_sigreturn, struct pt_regs *, regs)
 {
         struct rt_sigframe __user *frame =
                 (struct rt_sigframe __user *)(regs->sp);
         sigset_t set;
-        long r0;
 
         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
                 goto badframe;
@@ -96,13 +96,13 @@ SYSCALL_DEFINE1(rt_sigreturn, struct pt_regs *, regs)
         recalc_sigpending();
         spin_unlock_irq(&current->sighand->siglock);
 
-        if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
+        if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
                 goto badframe;
 
         if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
                 goto badframe;
 
-        return r0;
+        return 0;
 
 badframe:
         force_sig(SIGSEGV, current);
@@ -330,7 +330,7 @@ void do_signal(struct pt_regs *regs)
                         current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
                 }
 
-                return;
+                goto done;
         }
 
         /* Did we come from a system call? */
@@ -358,4 +358,8 @@ void do_signal(struct pt_regs *regs)
                 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
         }
+
+done:
+        /* Avoid double syscall restart if there are nested signals. */
+        regs->faultnum = INT_SWINT_1_SIGRETURN;
 }