alpha: unb0rk sigsuspend() and rt_sigsuspend()

Old code used to set regs->r0 and regs->r19 to force the right
return value.  Leaving that after switch to ERESTARTNOHAND
was a Bad Idea(tm), since now that screws the restart - if we
hit the case when get_signal_to_deliver() returns 0, we will
step back to syscall insn, with v0 set to EINTR and a3 to 1.
The latter won't matter, since EINTR is 4, aka __NR_write.

Testcase:

	#include <signal.h>
	#define _GNU_SOURCE
	#include <unistd.h>
	#include <sys/syscall.h>

	main()
	{
		sigset_t mask;
		sigemptyset(&mask);
		sigaddset(&mask, SIGCONT);
		sigprocmask(SIG_SETMASK, &mask, NULL);
		kill(0, SIGCONT);
		syscall(__NR_sigsuspend, 1, "b0rken\n", 7);
	}

results on alpha in immediate message to stdout...

Fix is obvious; moreover, since we don't need regs anymore, we can
switch to normal prototypes for these guys and lose the wrappers.
Even better, rt_sigsuspend() is identical to generic version in
kernel/signal.c now.

Tested-by: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matt Turner <mattst88@gmail.com>

diff --git a/arch/alpha/include/asm/unistd.h b/arch/alpha/include/asm/unistd.h
index 9a9672f0a346033e9dc4b00233b6f292346b6ddc..058937bf5a77718983126f2ab3813a023cb8c1d0 100644 (file)
--- a/arch/alpha/include/asm/unistd.h
+++ b/arch/alpha/include/asm/unistd.h
@@ -466,6 +466,7 @@
 #define __ARCH_WANT_SYS_OLD_GETRLIMIT
 #define __ARCH_WANT_SYS_OLDUMOUNT
 #define __ARCH_WANT_SYS_SIGPENDING
+#define __ARCH_WANT_SYS_RT_SIGSUSPEND
 
 /* "Conditional" syscalls.  What we want is
 

diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
index b45d913a51c368881b4311d1f1887566829b09a8..bceb325fd4c564d269ec07636cadaa850fefa9e6 100644 (file)
--- a/arch/alpha/kernel/entry.S
+++ b/arch/alpha/kernel/entry.S
@@ -778,38 +778,6 @@ sys_rt_sigreturn:
        br      ret_from_sys_call
 .end sys_rt_sigreturn
 
-       .align  4
-       .globl  sys_sigsuspend
-       .ent    sys_sigsuspend
-sys_sigsuspend:
-       .prologue 0
-       mov     $sp, $17
-       br      $1, do_switch_stack
-       mov     $sp, $18
-       subq    $sp, 16, $sp
-       stq     $26, 0($sp)
-       jsr     $26, do_sigsuspend
-       ldq     $26, 0($sp)
-       lda     $sp, SWITCH_STACK_SIZE+16($sp)
-       ret
-.end sys_sigsuspend
-
-       .align  4
-       .globl  sys_rt_sigsuspend
-       .ent    sys_rt_sigsuspend
-sys_rt_sigsuspend:
-       .prologue 0
-       mov     $sp, $18
-       br      $1, do_switch_stack
-       mov     $sp, $19
-       subq    $sp, 16, $sp
-       stq     $26, 0($sp)
-       jsr     $26, do_rt_sigsuspend
-       ldq     $26, 0($sp)
-       lda     $sp, SWITCH_STACK_SIZE+16($sp)
-       ret
-.end sys_rt_sigsuspend
-
        .align  4
        .globl  sys_sethae
        .ent    sys_sethae

diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c
index e5b1b3c79ff3f8172d686554666a753c6e4d6a26..0f6b51ae865aa87d70c3095cee6cec7057e0834a 100644 (file)
--- a/arch/alpha/kernel/signal.c
+++ b/arch/alpha/kernel/signal.c
@@ -144,8 +144,7 @@ SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
 /*
  * Atomically swap in the new signal mask, and wait for a signal.
  */
-asmlinkage int
-do_sigsuspend(old_sigset_t mask, struct pt_regs *regs, struct switch_stack *sw)
+SYSCALL_DEFINE1(sigsuspend, old_sigset_t, mask)
 {
        mask &= _BLOCKABLE;
        spin_lock_irq(&current->sighand->siglock);
@@ -154,41 +153,6 @@ do_sigsuspend(old_sigset_t mask, struct pt_regs *regs, struct switch_stack *sw)
        recalc_sigpending();
        spin_unlock_irq(&current->sighand->siglock);
 
-       /* Indicate EINTR on return from any possible signal handler,
-          which will not come back through here, but via sigreturn.  */
-       regs->r0 = EINTR;
-       regs->r19 = 1;
-
-       current->state = TASK_INTERRUPTIBLE;
-       schedule();
-       set_thread_flag(TIF_RESTORE_SIGMASK);
-       return -ERESTARTNOHAND;
-}
-
-asmlinkage int
-do_rt_sigsuspend(sigset_t __user *uset, size_t sigsetsize,
-                struct pt_regs *regs, struct switch_stack *sw)
-{
-       sigset_t set;
-
-       /* XXX: Don't preclude handling different sized sigset_t's.  */
-       if (sigsetsize != sizeof(sigset_t))
-               return -EINVAL;
-       if (copy_from_user(&set, uset, sizeof(set)))
-               return -EFAULT;
-
-       sigdelsetmask(&set, ~_BLOCKABLE);
-       spin_lock_irq(&current->sighand->siglock);
-       current->saved_sigmask = current->blocked;
-       current->blocked = set;
-       recalc_sigpending();
-       spin_unlock_irq(&current->sighand->siglock);
-
-       /* Indicate EINTR on return from any possible signal handler,
-          which will not come back through here, but via sigreturn.  */
-       regs->r0 = EINTR;
-       regs->r19 = 1;
-
        current->state = TASK_INTERRUPTIBLE;
        schedule();
        set_thread_flag(TIF_RESTORE_SIGMASK);