#include <linux/binfmts.h>
#include <linux/security.h>
#include <linux/syscalls.h>
-#include <linux/tracehook.h>
+#include <linux/ptrace.h>
#include <linux/signal.h>
#include <linux/capability.h>
#include <asm/param.h>
{
void __user * handler;
+ /*
+ * Tracers always want to know about signals..
+ */
+ if (t->ptrace & PT_PTRACED)
+ return 0;
+
/*
* Blocked signals are never ignored, since the
* signal handler may change by the time it is
/* Is it explicitly or implicitly ignored? */
handler = t->sighand->action[sig-1].sa.sa_handler;
- if (handler != SIG_IGN &&
- (handler != SIG_DFL || !sig_kernel_ignore(sig)))
- return 0;
-
- /* It's ignored, we can short-circuit unless a debugger wants it. */
- return !tracehook_consider_ignored_signal(t, sig, handler);
+ return handler == SIG_IGN ||
+ (handler == SIG_DFL && sig_kernel_ignore(sig));
}
/*
if (t->signal->group_stop_count > 0 ||
(freezing(t)) ||
PENDING(&t->pending, &t->blocked) ||
- PENDING(&t->signal->shared_pending, &t->blocked) ||
- tracehook_induce_sigpending(t))
+ PENDING(&t->signal->shared_pending, &t->blocked))
set_tsk_thread_flag(t, TIF_SIGPENDING);
else
clear_tsk_thread_flag(t, TIF_SIGPENDING);
return error;
}
+/* forward decl */
+static void do_notify_parent_cldstop(struct task_struct *tsk, int why);
/*
* Handle magic process-wide effects of stop/continue signals.
*/
if (sig_fatal(p, sig) && !(p->signal->flags & SIGNAL_GROUP_EXIT) &&
!sigismember(&t->real_blocked, sig) &&
- (sig == SIGKILL || !tracehook_consider_fatal_signal(t, sig))) {
+ (sig == SIGKILL || !(t->ptrace & PT_PTRACED))) {
/*
* This signal will be fatal to the whole group.
*/
/* do_notify_parent_cldstop should have been called instead. */
BUG_ON(tsk->state & (TASK_STOPPED|TASK_TRACED));
- BUG_ON(tsk->group_leader != tsk || !thread_group_empty(tsk));
+ BUG_ON(!tsk->ptrace &&
+ (tsk->group_leader != tsk || !thread_group_empty(tsk)));
info.si_signo = sig;
info.si_errno = 0;
psig = tsk->parent->sighand;
spin_lock_irqsave(&psig->siglock, flags);
- if (sig == SIGCHLD &&
+ if (!tsk->ptrace && sig == SIGCHLD &&
(psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN ||
(psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) {
/*
spin_unlock_irqrestore(&psig->siglock, flags);
}
-void do_notify_parent_cldstop(struct task_struct *tsk, int why)
+static void do_notify_parent_cldstop(struct task_struct *tsk, int why)
{
struct siginfo info;
unsigned long flags;
struct task_struct *parent;
struct sighand_struct *sighand;
+ if (tsk->ptrace & PT_PTRACED)
+ parent = tsk->parent;
+ else {
+ tsk = tsk->group_leader;
+ parent = tsk->real_parent;
+ }
+
info.si_signo = SIGCHLD;
info.si_errno = 0;
info.si_pid = tsk->pid;
BUG();
}
- /*
- * Tracing can decide that we should not do the normal notification.
- */
- if (tracehook_notify_cldstop(tsk, &info))
- return;
-
- tsk = tsk->group_leader;
- parent = tsk->parent;
-
sighand = parent->sighand;
spin_lock_irqsave(&sighand->siglock, flags);
if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN &&
spin_unlock_irqrestore(&sighand->siglock, flags);
}
+static inline int may_ptrace_stop(void)
+{
+ if (!likely(current->ptrace & PT_PTRACED))
+ return 0;
+
+ if (unlikely(current->parent == current->real_parent &&
+ (current->ptrace & PT_ATTACHED)))
+ return 0;
+
+ if (unlikely(current->signal == current->parent->signal) &&
+ unlikely(current->signal->flags & SIGNAL_GROUP_EXIT))
+ return 0;
+
+ /*
+ * Are we in the middle of do_coredump?
+ * If so and our tracer is also part of the coredump stopping
+ * is a deadlock situation, and pointless because our tracer
+ * is dead so don't allow us to stop.
+ * If SIGKILL was already sent before the caller unlocked
+ * ->siglock we must see ->core_waiters != 0. Otherwise it
+ * is safe to enter schedule().
+ */
+ if (unlikely(current->mm->core_waiters) &&
+ unlikely(current->mm == current->parent->mm))
+ return 0;
+
+ return 1;
+}
+
+/*
+ * This must be called with current->sighand->siglock held.
+ *
+ * This should be the path for all ptrace stops.
+ * We always set current->last_siginfo while stopped here.
+ * That makes it a way to test a stopped process for
+ * being ptrace-stopped vs being job-control-stopped.
+ *
+ * If we actually decide not to stop at all because the tracer is gone,
+ * we leave nostop_code in current->exit_code.
+ */
+static void ptrace_stop(int exit_code, int nostop_code, siginfo_t *info)
+{
+ /*
+ * If there is a group stop in progress,
+ * we must participate in the bookkeeping.
+ */
+ if (current->signal->group_stop_count > 0)
+ --current->signal->group_stop_count;
+
+ current->last_siginfo = info;
+ current->exit_code = exit_code;
+
+ /* Let the debugger run. */
+ set_current_state(TASK_TRACED);
+ spin_unlock_irq(¤t->sighand->siglock);
+ try_to_freeze();
+ read_lock(&tasklist_lock);
+ if (may_ptrace_stop()) {
+ do_notify_parent_cldstop(current, CLD_TRAPPED);
+ read_unlock(&tasklist_lock);
+ schedule();
+ } else {
+ /*
+ * By the time we got the lock, our tracer went away.
+ * Don't stop here.
+ */
+ read_unlock(&tasklist_lock);
+ set_current_state(TASK_RUNNING);
+ current->exit_code = nostop_code;
+ }
+
+ /*
+ * We are back. Now reacquire the siglock before touching
+ * last_siginfo, so that we are sure to have synchronized with
+ * any signal-sending on another CPU that wants to examine it.
+ */
+ spin_lock_irq(¤t->sighand->siglock);
+ current->last_siginfo = NULL;
+
+ /*
+ * Queued signals ignored us while we were stopped for tracing.
+ * So check for any that we should take before resuming user mode.
+ */
+ recalc_sigpending();
+}
+
+void ptrace_notify(int exit_code)
+{
+ siginfo_t info;
+
+ BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP);
+
+ memset(&info, 0, sizeof info);
+ info.si_signo = SIGTRAP;
+ info.si_code = exit_code;
+ info.si_pid = current->pid;
+ info.si_uid = current->uid;
+
+ /* Let the debugger run. */
+ spin_lock_irq(¤t->sighand->siglock);
+ ptrace_stop(exit_code, 0, &info);
+ spin_unlock_irq(¤t->sighand->siglock);
+}
+
static void
finish_stop(int stop_count)
{
* a group stop in progress and we are the last to stop,
* report to the parent. When ptraced, every thread reports itself.
*/
- if (!tracehook_finish_stop(stop_count <= 0) && stop_count <= 0) {
+ if (stop_count == 0 || (current->ptrace & PT_PTRACED)) {
read_lock(&tasklist_lock);
do_notify_parent_cldstop(current, CLD_STOPPED);
read_unlock(&tasklist_lock);
handle_group_stop())
goto relock;
- /*
- * Tracing can induce an artifical signal and choose sigaction.
- * The return value in signr determines the default action,
- * but info->si_signo is the signal number we will report.
- */
- signr = tracehook_get_signal(current, regs, info, return_ka);
- if (unlikely(signr < 0))
- goto relock;
- if (unlikely(signr != 0))
- ka = return_ka;
- else {
- signr = dequeue_signal(current, mask, info);
-
- if (!signr)
- break; /* will return 0 */
- ka = ¤t->sighand->action[signr-1];
+ signr = dequeue_signal(current, mask, info);
+
+ if (!signr)
+ break; /* will return 0 */
+
+ if ((current->ptrace & PT_PTRACED) && signr != SIGKILL) {
+ ptrace_signal_deliver(regs, cookie);
+
+ /* Let the debugger run. */
+ ptrace_stop(signr, signr, info);
+
+ /* We're back. Did the debugger cancel the sig? */
+ signr = current->exit_code;
+ if (signr == 0)
+ continue;
+
+ current->exit_code = 0;
+
+ /* Update the siginfo structure if the signal has
+ changed. If the debugger wanted something
+ specific in the siginfo structure then it should
+ have updated *info via PTRACE_SETSIGINFO. */
+ if (signr != info->si_signo) {
+ info->si_signo = signr;
+ info->si_errno = 0;
+ info->si_code = SI_USER;
+ info->si_pid = current->parent->pid;
+ info->si_uid = current->parent->uid;
+ }
+
+ /* If the (new) signal is now blocked, requeue it. */
+ if (sigismember(¤t->blocked, signr)) {
+ specific_send_sig_info(signr, info, current);
+ continue;
+ }
}
+ ka = ¤t->sighand->action[signr-1];
if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */
continue;
if (ka->sa.sa_handler != SIG_DFL) {
spin_lock_irq(¤t->sighand->siglock);
}
- if (likely(do_signal_stop(info->si_signo))) {
+ if (likely(do_signal_stop(signr))) {
/* It released the siglock. */
goto relock;
}
* first and our do_group_exit call below will use
* that value and ignore the one we pass it.
*/
- do_coredump(info->si_signo, info->si_signo, regs);
+ do_coredump((long)signr, signr, regs);
}
/*
* Death signals, no core dump.
*/
- do_group_exit(info->si_signo);
+ do_group_exit(signr);
/* NOTREACHED */
}
spin_unlock_irq(¤t->sighand->siglock);
EXPORT_SYMBOL(force_sig);
EXPORT_SYMBOL(kill_pg);
EXPORT_SYMBOL(kill_proc);
+EXPORT_SYMBOL(ptrace_notify);
EXPORT_SYMBOL(send_sig);
EXPORT_SYMBOL(send_sig_info);
EXPORT_SYMBOL(sigprocmask);
git://git.onelab.eu / linux-2.6.git / blobdiff