Module Name: src
Committed By: christos
Date: Thu Dec 7 19:49:43 UTC 2017
Modified Files:
src/sys/kern: kern_sig.c
Log Message:
- Reset ignored or masked traps to avoid infinite loops
- If sigpost fails don't add an SDT_PROBE
ok (and author) chuq
To generate a diff of this commit:
cvs rdiff -u -r1.338 -r1.339 src/sys/kern/kern_sig.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/kern_sig.c
diff -u src/sys/kern/kern_sig.c:1.338 src/sys/kern/kern_sig.c:1.339
--- src/sys/kern/kern_sig.c:1.338 Wed Oct 25 04:12:39 2017
+++ src/sys/kern/kern_sig.c Thu Dec 7 14:49:43 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_sig.c,v 1.338 2017/10/25 08:12:39 maya Exp $ */
+/* $NetBSD: kern_sig.c,v 1.339 2017/12/07 19:49:43 christos Exp $ */
/*-
* Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -70,7 +70,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_sig.c,v 1.338 2017/10/25 08:12:39 maya Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_sig.c,v 1.339 2017/12/07 19:49:43 christos Exp $");
#include "opt_ptrace.h"
#include "opt_dtrace.h"
@@ -903,9 +903,10 @@ trapsignal(struct lwp *l, ksiginfo_t *ks
mask = &l->l_sigmask;
ps = p->p_sigacts;
- if ((p->p_slflag & PSL_TRACED) == 0 &&
- sigismember(&p->p_sigctx.ps_sigcatch, signo) &&
- !sigismember(mask, signo)) {
+ const bool traced = (p->p_slflag & PSL_TRACED) != 0;
+ const bool caught = sigismember(&p->p_sigctx.ps_sigcatch, signo);
+ const bool masked = sigismember(mask, signo);
+ if (!traced && caught && !masked) {
mutex_exit(proc_lock);
l->l_ru.ru_nsignals++;
kpsendsig(l, ksi, mask);
@@ -920,11 +921,28 @@ trapsignal(struct lwp *l, ksiginfo_t *ks
SIGACTION_PS(ps, signo).sa_handler,
mask, ksi);
}
- } else {
- kpsignal2(p, ksi);
- mutex_exit(p->p_lock);
- mutex_exit(proc_lock);
+ return;
+ }
+
+ /*
+ * If the signal is masked or ignored, then unmask it and
+ * reset it to the default action so that the process or
+ * its tracer will be notified.
+ */
+ const bool ignored = SIGACTION_PS(ps, signo).sa_handler == SIG_IGN;
+ if (masked || ignored) {
+ mutex_enter(&ps->sa_mutex);
+ sigdelset(mask, signo);
+ sigdelset(&p->p_sigctx.ps_sigcatch, signo);
+ sigdelset(&p->p_sigctx.ps_sigignore, signo);
+ sigdelset(&SIGACTION_PS(ps, signo).sa_mask, signo);
+ SIGACTION_PS(ps, signo).sa_handler = SIG_DFL;
+ mutex_exit(&ps->sa_mutex);
}
+
+ kpsignal2(p, ksi);
+ mutex_exit(p->p_lock);
+ mutex_exit(proc_lock);
}
/*
@@ -1215,7 +1233,6 @@ int
kpsignal2(struct proc *p, ksiginfo_t *ksi)
{
int prop, signo = ksi->ksi_signo;
- struct sigacts *sa;
struct lwp *l = NULL;
ksiginfo_t *kp;
lwpid_t lid;
@@ -1275,20 +1292,6 @@ kpsignal2(struct proc *p, ksiginfo_t *ks
goto out;
}
} else {
- /*
- * If the signal was the result of a trap and is not being
- * caught, then reset it to default action so that the
- * process dumps core immediately.
- */
- if (KSI_TRAP_P(ksi)) {
- sa = p->p_sigacts;
- mutex_enter(&sa->sa_mutex);
- if (!sigismember(&p->p_sigctx.ps_sigcatch, signo)) {
- sigdelset(&p->p_sigctx.ps_sigignore, signo);
- SIGACTION(p, signo).sa_handler = SIG_DFL;
- }
- mutex_exit(&sa->sa_mutex);
- }
/*
* If the signal is being ignored, then drop it. Note: we
@@ -1365,7 +1368,8 @@ kpsignal2(struct proc *p, ksiginfo_t *ks
if ((error = sigput(&l->l_sigpend, p, kp)) != 0)
goto out;
membar_producer();
- (void)sigpost(l, action, prop, kp->ksi_signo);
+ if (sigpost(l, action, prop, kp->ksi_signo) != 0)
+ signo = -1;
}
goto out;
}
