diff options
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 45 |
1 files changed, 38 insertions, 7 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 7c4b7ae714d4..dfcee3888b00 100644 --- 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 +1668,20 @@ 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); +} + +void force_exit_sig(int sig) +{ + struct kernel_siginfo info; + + clear_siginfo(&info); + info.si_signo = sig; + info.si_errno = 0; + info.si_code = SI_KERNEL; + info.si_pid = 0; + info.si_uid = 0; + force_sig_info_to_task(&info, current, HANDLER_EXIT); } /* @@ -1693,7 +1714,7 @@ 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 +1834,8 @@ 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 @@ -4163,6 +4185,15 @@ do_sigaltstack (const stack_t *ss, stack_t *oss, unsigned long sp, ss_mode != 0)) return -EINVAL; + /* + * Return before taking any locks if no actual + * sigaltstack changes were requested. + */ + if (t->sas_ss_sp == (unsigned long)ss_sp && + t->sas_ss_size == ss_size && + t->sas_ss_flags == ss_flags) + return 0; + sigaltstack_lock(); if (ss_mode == SS_DISABLE) { ss_size = 0; |