diff options
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 56 |
1 files changed, 38 insertions, 18 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index c73c4284160e..17afcaf582d0 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -36,6 +36,7 @@ #include <asm/uaccess.h> #include <asm/unistd.h> #include <asm/siginfo.h> +#include <asm/cacheflush.h> #include "audit.h" /* audit_signal_info() */ /* @@ -58,21 +59,20 @@ static int sig_handler_ignored(void __user *handler, int sig) (handler == SIG_DFL && sig_kernel_ignore(sig)); } -static int sig_task_ignored(struct task_struct *t, int sig, - int from_ancestor_ns) +static int sig_task_ignored(struct task_struct *t, int sig, bool force) { void __user *handler; handler = sig_handler(t, sig); if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && - handler == SIG_DFL && !from_ancestor_ns) + handler == SIG_DFL && !force) return 1; return sig_handler_ignored(handler, sig); } -static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns) +static int sig_ignored(struct task_struct *t, int sig, bool force) { /* * Blocked signals are never ignored, since the @@ -82,7 +82,7 @@ static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns) if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig)) return 0; - if (!sig_task_ignored(t, sig, from_ancestor_ns)) + if (!sig_task_ignored(t, sig, force)) return 0; /* @@ -855,7 +855,7 @@ static void ptrace_trap_notify(struct task_struct *t) * Returns true if the signal should be actually delivered, otherwise * it should be dropped. */ -static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns) +static int prepare_signal(int sig, struct task_struct *p, bool force) { struct signal_struct *signal = p->signal; struct task_struct *t; @@ -915,7 +915,7 @@ static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns) } } - return !sig_ignored(p, sig, from_ancestor_ns); + return !sig_ignored(p, sig, force); } /* @@ -1054,13 +1054,14 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, struct sigpending *pending; struct sigqueue *q; int override_rlimit; - - trace_signal_generate(sig, info, t); + int ret = 0, result; assert_spin_locked(&t->sighand->siglock); - if (!prepare_signal(sig, t, from_ancestor_ns)) - return 0; + result = TRACE_SIGNAL_IGNORED; + if (!prepare_signal(sig, t, + from_ancestor_ns || (info == SEND_SIG_FORCED))) + goto ret; pending = group ? &t->signal->shared_pending : &t->pending; /* @@ -1068,8 +1069,11 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, * exactly one non-rt signal, so that we can get more * detailed information about the cause of the signal. */ + result = TRACE_SIGNAL_ALREADY_PENDING; if (legacy_queue(pending, sig)) - return 0; + goto ret; + + result = TRACE_SIGNAL_DELIVERED; /* * fast-pathed signals for kernel-internal things like SIGSTOP * or SIGKILL. @@ -1127,14 +1131,15 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, * signal was rt and sent by user using something * other than kill(). */ - trace_signal_overflow_fail(sig, group, info); - return -EAGAIN; + result = TRACE_SIGNAL_OVERFLOW_FAIL; + ret = -EAGAIN; + goto ret; } else { /* * This is a silent loss of information. We still * send the signal, but the *info bits are lost. */ - trace_signal_lose_info(sig, group, info); + result = TRACE_SIGNAL_LOSE_INFO; } } @@ -1142,7 +1147,9 @@ out_set: signalfd_notify(t, sig); sigaddset(&pending->signal, sig); complete_signal(sig, t, group); - return 0; +ret: + trace_signal_generate(sig, info, t, group, result); + return ret; } static int send_signal(int sig, struct siginfo *info, struct task_struct *t, @@ -1585,7 +1592,7 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) int sig = q->info.si_signo; struct sigpending *pending; unsigned long flags; - int ret; + int ret, result; BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); @@ -1594,7 +1601,8 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) goto ret; ret = 1; /* the signal is ignored */ - if (!prepare_signal(sig, t, 0)) + result = TRACE_SIGNAL_IGNORED; + if (!prepare_signal(sig, t, false)) goto out; ret = 0; @@ -1605,6 +1613,7 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) */ BUG_ON(q->info.si_code != SI_TIMER); q->info.si_overrun++; + result = TRACE_SIGNAL_ALREADY_PENDING; goto out; } q->info.si_overrun = 0; @@ -1614,7 +1623,9 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) list_add_tail(&q->list, &pending->list); sigaddset(&pending->signal, sig); complete_signal(sig, t, group); + result = TRACE_SIGNAL_DELIVERED; out: + trace_signal_generate(sig, &q->info, t, group, result); unlock_task_sighand(t, &flags); ret: return ret; @@ -1642,6 +1653,15 @@ bool do_notify_parent(struct task_struct *tsk, int sig) BUG_ON(!tsk->ptrace && (tsk->group_leader != tsk || !thread_group_empty(tsk))); + if (sig != SIGCHLD) { + /* + * This is only possible if parent == real_parent. + * Check if it has changed security domain. + */ + if (tsk->parent_exec_id != tsk->parent->self_exec_id) + sig = SIGCHLD; + } + info.si_signo = sig; info.si_errno = 0; /* |