MIPS: Sanitize restart logics

[mv-sheeva.git] / arch / mips / kernel / signal.c

diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 2099d5a4c4b78224f85ee5f9b175907be3d8f15c..604f077bb5bf701755d5fd36428ca602792b1898 100644 (file)
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -550,23 +550,26 @@ 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 +578,9 @@ 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 +628,13 @@ 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;