Module Name: src
Committed By: kamil
Date: Sat Oct 12 19:57:09 UTC 2019
Modified Files:
src/sys/kern: kern_sig.c
src/sys/sys: signalvar.h
Log Message:
Refactor sigswitch()
Make the function static as it is now local to kern_sig.c.
Rename the 'relock' argument to 'proc_lock_held' as it is more verbose.
This was suggested by mjg@freebsd. While there this flips the users between
true<->false.
Add additional KASSERT(9) calls here to validate whethe proc_lock is used
accordingly.
To generate a diff of this commit:
cvs rdiff -u -r1.368 -r1.369 src/sys/kern/kern_sig.c
cvs rdiff -u -r1.96 -r1.97 src/sys/sys/signalvar.h
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:1.368 src/sys/kern/kern_sig.c:1.369
--- src/sys/kern/kern_sig.c:1.368 Sat Oct 12 10:55:23 2019
+++ src/sys/kern/kern_sig.c Sat Oct 12 19:57:09 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_sig.c,v 1.368 2019/10/12 10:55:23 kamil Exp $ */
+/* $NetBSD: kern_sig.c,v 1.369 2019/10/12 19:57:09 kamil 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 1.368 2019/10/12 10:55:23 kamil Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_sig.c,v 1.369 2019/10/12 19:57:09 kamil Exp $");
#include "opt_ptrace.h"
#include "opt_dtrace.h"
@@ -125,6 +125,7 @@ static int sigchecktrace(void);
static int sigpost(struct lwp *, sig_t, int, int);
static int sigput(sigpend_t *, struct proc *, ksiginfo_t *);
static int sigunwait(struct proc *, const ksiginfo_t *);
+static void sigswitch(int, int, bool);
static void sigacts_poolpage_free(struct pool *, void *);
static void *sigacts_poolpage_alloc(struct pool *, int);
@@ -931,7 +932,7 @@ repeat:
* The process is already stopping.
*/
if ((p->p_sflag & PS_STOPPING) != 0) {
- sigswitch(0, p->p_xsig, false);
+ sigswitch(0, p->p_xsig, true);
mutex_enter(proc_lock);
mutex_enter(p->p_lock);
goto repeat; /* XXX */
@@ -949,7 +950,7 @@ repeat:
p->p_sigctx.ps_faked = true;
p->p_sigctx.ps_lwp = ksi->ksi_lid;
p->p_sigctx.ps_info = ksi->ksi_info;
- sigswitch(0, signo, false);
+ sigswitch(0, signo, true);
if (ktrpoint(KTR_PSIG)) {
if (p->p_emul->e_ktrpsig)
@@ -1641,7 +1642,7 @@ repeat:
* The process is already stopping.
*/
if ((p->p_sflag & PS_STOPPING) != 0) {
- sigswitch(0, p->p_xsig, false);
+ sigswitch(0, p->p_xsig, true);
mutex_enter(proc_lock);
mutex_enter(p->p_lock);
goto repeat; /* XXX */
@@ -1666,7 +1667,7 @@ repeat:
p->p_sigctx.ps_lwp = ksi.ksi_lid;
p->p_sigctx.ps_info = ksi.ksi_info;
- sigswitch(0, signo, false);
+ sigswitch(0, signo, true);
if (code == TRAP_CHLD) {
mutex_enter(proc_lock);
@@ -1686,8 +1687,8 @@ repeat:
/*
* Stop the current process and switch away when being stopped or traced.
*/
-void
-sigswitch(int ppmask, int signo, bool relock)
+static void
+sigswitch(int ppmask, int signo, bool proc_lock_held)
{
struct lwp *l = curlwp;
struct proc *p = l->l_proc;
@@ -1697,6 +1698,12 @@ sigswitch(int ppmask, int signo, bool re
KASSERT(l->l_stat == LSONPROC);
KASSERT(p->p_nrlwps > 0);
+ if (proc_lock_held) {
+ KASSERT(mutex_owned(proc_lock));
+ } else {
+ KASSERT(!mutex_owned(proc_lock));
+ }
+
/*
* If we are exiting, demise now.
*
@@ -1704,7 +1711,7 @@ sigswitch(int ppmask, int signo, bool re
*/
if (__predict_false(ISSET(p->p_sflag, PS_WEXIT))) {
mutex_exit(p->p_lock);
- if (!relock) {
+ if (proc_lock_held) {
mutex_exit(proc_lock);
}
lwp_exit(l);
@@ -1728,7 +1735,7 @@ sigswitch(int ppmask, int signo, bool re
* a new signal, then signal the parent.
*/
if ((p->p_sflag & PS_STOPPING) != 0) {
- if (relock && !mutex_tryenter(proc_lock)) {
+ if (!proc_lock_held && !mutex_tryenter(proc_lock)) {
mutex_exit(p->p_lock);
mutex_enter(proc_lock);
mutex_enter(p->p_lock);
@@ -1748,6 +1755,7 @@ sigswitch(int ppmask, int signo, bool re
/*
* Unlock and switch away.
*/
+ KASSERT(!mutex_owned(proc_lock));
KERNEL_UNLOCK_ALL(l, &biglocks);
if (p->p_stat == SSTOP || (p->p_sflag & PS_STOPPING) != 0) {
p->p_nrlwps--;
@@ -1837,7 +1845,7 @@ issignal(struct lwp *l)
* we awaken, check for a signal from the debugger.
*/
if (p->p_stat == SSTOP || (p->p_sflag & PS_STOPPING) != 0) {
- sigswitch(PS_NOCLDSTOP, 0, true);
+ sigswitch(PS_NOCLDSTOP, 0, false);
mutex_enter(p->p_lock);
signo = sigchecktrace();
} else if (p->p_stat == SACTIVE)
@@ -1909,7 +1917,7 @@ issignal(struct lwp *l)
p->p_xsig = signo;
/* Handling of signal trace */
- sigswitch(0, signo, true);
+ sigswitch(0, signo, false);
mutex_enter(p->p_lock);
/* Check for a signal from the debugger. */
@@ -1966,7 +1974,7 @@ issignal(struct lwp *l)
p->p_xsig = signo;
p->p_sflag &= ~PS_CONTINUED;
signo = 0;
- sigswitch(PS_NOCLDSTOP, p->p_xsig, true);
+ sigswitch(PS_NOCLDSTOP, p->p_xsig, false);
mutex_enter(p->p_lock);
} else if (prop & SA_IGNORE) {
/*
@@ -2519,7 +2527,7 @@ repeat:
* The process is already stopping.
*/
if ((p->p_sflag & PS_STOPPING) != 0) {
- sigswitch(0, p->p_xsig, true);
+ sigswitch(0, p->p_xsig, false);
mutex_enter(p->p_lock);
goto repeat; /* XXX */
}
@@ -2532,7 +2540,7 @@ repeat:
p->p_xsig = signo;
p->p_sigctx.ps_lwp = ksi.ksi_lid;
p->p_sigctx.ps_info = ksi.ksi_info;
- sigswitch(0, signo, true);
+ sigswitch(0, signo, false);
if (ktrpoint(KTR_PSIG)) {
if (p->p_emul->e_ktrpsig)
Index: src/sys/sys/signalvar.h
diff -u src/sys/sys/signalvar.h:1.96 src/sys/sys/signalvar.h:1.97
--- src/sys/sys/signalvar.h:1.96 Mon Sep 30 21:13:33 2019
+++ src/sys/sys/signalvar.h Sat Oct 12 19:57:09 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: signalvar.h,v 1.96 2019/09/30 21:13:33 kamil Exp $ */
+/* $NetBSD: signalvar.h,v 1.97 2019/10/12 19:57:09 kamil Exp $ */
/*
* Copyright (c) 1991, 1993
@@ -153,7 +153,6 @@ void setsigvec(struct proc *, int, struc
int killpg1(struct lwp *, struct ksiginfo *, int, int);
void proc_unstop(struct proc *p);
void eventswitch(int, int, int);
-void sigswitch(int, int, bool);
int sigaction1(struct lwp *, int, const struct sigaction *,
