1 files changed, 22 insertions, 23 deletions

diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 2099d5a4c4b7..5922342bca39 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -390,7 +390,6 @@ asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 {
         struct rt_sigframe __user *frame;
         sigset_t set;
-        stack_t st;
         int sig;
 
         frame = (struct rt_sigframe __user *) regs.regs[29];
@@ -411,11 +410,9 @@ asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
         else if (sig)
                 force_sig(sig, current);
 
-        if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
-                goto badframe;
         /* It is more difficult to avoid calling this function than to
            call it and ignore errors.  */
-        do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
+        do_sigaltstack(&frame->rs_uc.uc_stack, NULL, regs.regs[29]);
 
         /*
          * Don't let your children do this ...
@@ -550,23 +547,26 @@ static int handle_signal(unsigned long sig, siginfo_t *info,
         struct mips_abi *abi = current->thread.abi;
         void *vdso = current->mm->context.vdso;
 
-        switch(regs->regs[0]) {
-        case ERESTART_RESTARTBLOCK:
-        case ERESTARTNOHAND:
-                regs->regs[2] = EINTR;
-                break;
-        case ERESTARTSYS:
-                if (!(ka->sa.sa_flags & SA_RESTART)) {
+        if (regs->regs[0]) {
+                switch(regs->regs[2]) {
+                case ERESTART_RESTARTBLOCK:
+                case ERESTARTNOHAND:
                         regs->regs[2] = EINTR;
                         break;
+                case ERESTARTSYS:
+                        if (!(ka->sa.sa_flags & SA_RESTART)) {
+                                regs->regs[2] = EINTR;
+                                break;
+                        }
+                /* fallthrough */
+                case ERESTARTNOINTR:
+                        regs->regs[7] = regs->regs[26];
+                        regs->regs[2] = regs->regs[0];
+                        regs->cp0_epc -= 4;
                 }
-        /* fallthrough */
-        case ERESTARTNOINTR:            /* Userland will reload $v0.  */
-                regs->regs[7] = regs->regs[26];
-                regs->cp0_epc -= 8;
-        }
 
-        regs->regs[0] = 0;              /* Don't deal with this again.  */
+                regs->regs[0] = 0;              /* Don't deal with this again.  */
+        }
 
         if (sig_uses_siginfo(ka))
                 ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset,
@@ -575,6 +575,9 @@ static int handle_signal(unsigned long sig, siginfo_t *info,
                 ret = abi->setup_frame(vdso + abi->signal_return_offset,
                                        ka, regs, sig, oldset);
 
+        if (ret)
+                return ret;
+
         spin_lock_irq(&current->sighand->siglock);
         sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
         if (!(ka->sa.sa_flags & SA_NODEFER))
@@ -622,17 +625,13 @@ static void do_signal(struct pt_regs *regs)
                 return;
         }
 
-        /*
-         * Who's code doesn't conform to the restartable syscall convention
-         * dies here!!!  The li instruction, a single machine instruction,
-         * must directly be followed by the syscall instruction.
-         */
         if (regs->regs[0]) {
                 if (regs->regs[2] == ERESTARTNOHAND ||
                     regs->regs[2] == ERESTARTSYS ||
                     regs->regs[2] == ERESTARTNOINTR) {
+                        regs->regs[2] = regs->regs[0];
                         regs->regs[7] = regs->regs[26];
-                        regs->cp0_epc -= 8;
+                        regs->cp0_epc -= 4;
                 }
                 if (regs->regs[2] == ERESTART_RESTARTBLOCK) {
                         regs->regs[2] = current->thread.abi->restart;