m68k: Wire up sys_restart_syscall

Make restart blocks working, required for proper syscall restarting.

Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

2 files changed, 16 insertions, 1 deletions

diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index f28404d9a2bc..5b780826647c 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -424,7 +424,7 @@ resume:
 .data
 ALIGN
 sys_call_table:
-        .long sys_ni_syscall    /* 0  -  old "setup()" system call*/
+        .long sys_restart_syscall       /* 0 - old "setup()" system call, used for restarting */
         .long sys_exit
         .long sys_fork
         .long sys_read
diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c
index f9af893cd289..de2d05ddd86d 100644
--- a/arch/m68k/kernel/signal.c
+++ b/arch/m68k/kernel/signal.c
@@ -326,6 +326,9 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __u
         struct sigcontext context;
         int err;
 
+        /* Always make any pending restarted system calls return -EINTR */
+        current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
         /* get previous context */
         if (copy_from_user(&context, usc, sizeof(context)))
                 goto badframe;
@@ -411,6 +414,9 @@ rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
         unsigned long usp;
         int err;
 
+        /* Always make any pending restarted system calls return -EINTR */
+        current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
         err = __get_user(temp, &uc->uc_mcontext.version);
         if (temp != MCONTEXT_VERSION)
                 goto badframe;
@@ -937,6 +943,15 @@ handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
                 regs->d0 = -EINTR;
                 break;
 
+        case -ERESTART_RESTARTBLOCK:
+                if (!has_handler) {
+                        regs->d0 = __NR_restart_syscall;
+                        regs->pc -= 2;
+                        break;
+                }
+                regs->d0 = -EINTR;
+                break;
+
         case -ERESTARTSYS:
                 if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
                         regs->d0 = -EINTR;