signal: Don't always set SA_IMMUTABLE for forced signals

[linux-2.6-block.git] / kernel / signal.c

diff --git a/kernel/signal.c b/kernel/signal.c
index 7c4b7ae714d47f942c87547518112fbb5be35bf3..7815e1bbeddc570fb885e995e4e61668aa422069 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1298,6 +1298,12 @@ int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p
        return ret;
 }
 
+enum sig_handler {
+       HANDLER_CURRENT, /* If reachable use the current handler */
+       HANDLER_SIG_DFL, /* Always use SIG_DFL handler semantics */
+       HANDLER_EXIT,    /* Only visible as the process exit code */
+};
+
 /*
  * Force a signal that the process can't ignore: if necessary
  * we unblock the signal and change any SIG_IGN to SIG_DFL.
@@ -1310,7 +1316,8 @@ int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p
  * that is why we also clear SIGNAL_UNKILLABLE.
  */
 static int
-force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool sigdfl)
+force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t,
+       enum sig_handler handler)
 {
        unsigned long int flags;
        int ret, blocked, ignored;
@@ -1321,9 +1328,10 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool
        action = &t->sighand->action[sig-1];
        ignored = action->sa.sa_handler == SIG_IGN;
        blocked = sigismember(&t->blocked, sig);
-       if (blocked || ignored || sigdfl) {
+       if (blocked || ignored || (handler != HANDLER_CURRENT)) {
                action->sa.sa_handler = SIG_DFL;
-               action->sa.sa_flags |= SA_IMMUTABLE;
+               if (handler == HANDLER_EXIT)
+                       action->sa.sa_flags |= SA_IMMUTABLE;
                if (blocked) {
                        sigdelset(&t->blocked, sig);
                        recalc_sigpending_and_wake(t);
@@ -1343,7 +1351,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool
 
 int force_sig_info(struct kernel_siginfo *info)
 {
-       return force_sig_info_to_task(info, current, false);
+       return force_sig_info_to_task(info, current, HANDLER_CURRENT);
 }
 
 /*
@@ -1660,7 +1668,7 @@ void force_fatal_sig(int sig)
        info.si_code = SI_KERNEL;
        info.si_pid = 0;
        info.si_uid = 0;
-       force_sig_info_to_task(&info, current, true);
+       force_sig_info_to_task(&info, current, HANDLER_SIG_DFL);
 }
 
 /*
@@ -1693,7 +1701,7 @@ int force_sig_fault_to_task(int sig, int code, void __user *addr
        info.si_flags = flags;
        info.si_isr = isr;
 #endif
-       return force_sig_info_to_task(&info, t, false);
+       return force_sig_info_to_task(&info, t, HANDLER_CURRENT);
 }
 
 int force_sig_fault(int sig, int code, void __user *addr
@@ -1813,7 +1821,8 @@ int force_sig_seccomp(int syscall, int reason, bool force_coredump)
        info.si_errno = reason;
        info.si_arch = syscall_get_arch(current);
        info.si_syscall = syscall;
-       return force_sig_info_to_task(&info, current, force_coredump);
+       return force_sig_info_to_task(&info, current,
+               force_coredump ? HANDLER_EXIT : HANDLER_CURRENT);
 }
 
 /* For the crazy architectures that include trap information in