diff options
author | Al Viro <viro@zeniv.linux.org.uk> | 2010-09-18 08:40:07 -0400 |
---|---|---|
committer | Matt Turner <mattst88@gmail.com> | 2010-09-18 23:08:28 -0400 |
commit | 392fb6e35400edbee183baba24b34a0fa2053813 (patch) | |
tree | e11587c8b7ca75ab41b23f9e09e2c6a9365e2187 | |
parent | 2deba1bd7126aadb5750beb927c878a6490065e6 (diff) | |
download | op-kernel-dev-392fb6e35400edbee183baba24b34a0fa2053813.zip op-kernel-dev-392fb6e35400edbee183baba24b34a0fa2053813.tar.gz |
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>
-rw-r--r-- | arch/alpha/include/asm/unistd.h | 1 | ||||
-rw-r--r-- | arch/alpha/kernel/entry.S | 32 | ||||
-rw-r--r-- | arch/alpha/kernel/signal.c | 38 |
3 files changed, 2 insertions, 69 deletions
diff --git a/arch/alpha/include/asm/unistd.h b/arch/alpha/include/asm/unistd.h index 9a9672f..058937b 100644 --- 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 b45d913..bceb325 100644 --- a/arch/alpha/kernel/entry.S +++ b/arch/alpha/kernel/entry.S @@ -779,38 +779,6 @@ sys_rt_sigreturn: .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 sys_sethae: diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c index e5b1b3c..0f6b51a 100644 --- 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(¤t->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(¤t->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(¤t->sighand->siglock); - current->saved_sigmask = current->blocked; - current->blocked = set; - recalc_sigpending(); - spin_unlock_irq(¤t->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); |