sh: __NR_restart_syscall support.

This implements support for __NR_restart_syscall.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

3 files changed, 13 insertions, 7 deletions

diff --git a/arch/sh/kernel/entry.S b/arch/sh/kernel/entry.S
index b087d34dba35..fcbf50d4ee10 100644
--- a/arch/sh/kernel/entry.S
+++ b/arch/sh/kernel/entry.S
@@ -376,6 +376,7 @@ work_notifysig:
         bt/s    restore_all
          mov    r15, r4
         mov     #0, r5
+        mov     r12, r6         ! set arg2(save_r0)
         mov.l   2f, r1
         mova    restore_all, r0
         jmp     @r1
@@ -534,6 +535,7 @@ syscall_call:
         mov.l   @r9, r8
         jsr     @r8             ! jump to specific syscall handler
          nop
+        mov.l   @(OFF_R0,r15), r12              ! save r0
         mov.l   r0, @(OFF_R0,r15)               ! save the return value
         !
 syscall_exit:
diff --git a/arch/sh/kernel/signal.c b/arch/sh/kernel/signal.c
index b475c4d2405f..eb6a3b97e46c 100644
--- a/arch/sh/kernel/signal.c
+++ b/arch/sh/kernel/signal.c
@@ -33,7 +33,8 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
-asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
+asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset,
+                         unsigned int save_r0);
 
 /*
  * Atomically swap in the new signal mask, and wait for a signal.
@@ -56,7 +57,7 @@ sys_sigsuspend(old_sigset_t mask,
         while (1) {
                 current->state = TASK_INTERRUPTIBLE;
                 schedule();
-                if (do_signal(&regs, &saveset))
+                if (do_signal(&regs, &saveset, regs.regs[0]))
                         return -EINTR;
         }
 }
@@ -85,7 +86,7 @@ sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
         while (1) {
                 current->state = TASK_INTERRUPTIBLE;
                 schedule();
-                if (do_signal(&regs, &saveset))
+                if (do_signal(&regs, &saveset, regs.regs[0]))
                         return -EINTR;
         }
 }
@@ -563,7 +564,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
  * the kernel can handle, and then we build all the user-level signal handling
  * stack-frames in one go after that.
  */
-int do_signal(struct pt_regs *regs, sigset_t *oldset)
+int do_signal(struct pt_regs *regs, sigset_t *oldset, unsigned int save_r0)
 {
         siginfo_t info;
         int signr;
@@ -597,9 +598,12 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
                 /* Restart the system call - no handlers present */
                 if (regs->regs[0] == -ERESTARTNOHAND ||
                     regs->regs[0] == -ERESTARTSYS ||
-                    regs->regs[0] == -ERESTARTNOINTR ||
-                    regs->regs[0] == -ERESTART_RESTARTBLOCK) {
+                    regs->regs[0] == -ERESTARTNOINTR) {
+                        regs->regs[0] = save_r0;
                         regs->pc -= 2;
+                } else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
+                        regs->pc -= 2;
+                        regs->regs[3] = __NR_restart_syscall;
                 }
         }
         return 0;
diff --git a/arch/sh/kernel/syscalls.S b/arch/sh/kernel/syscalls.S
index ada61b0d9a73..ea23b213c77f 100644
--- a/arch/sh/kernel/syscalls.S
+++ b/arch/sh/kernel/syscalls.S
@@ -34,7 +34,7 @@
 
         .data
 ENTRY(sys_call_table)
-        .long sys_ni_syscall    /* 0  -  old "setup()" system call*/
+        .long sys_restart_syscall       /* 0  -  old "setup()" system call*/
         .long sys_exit
         .long sys_fork
         .long sys_read