Sat Dec 3 16:25:50 2011 UTC ()
If we are DIAGNOSTIC don't try to go further if we failed to take the
lock, because we are going to trigger a KASSERT. Also hold the lock
longer and take the proc lock for kpsignal(). Maybe we should add
mutex_steal() and mutex_return() for the debugger? Lock correction
suggestion from jmcneill.


(christos)
diff -r1.65 -r1.66 src/sys/ddb/db_xxx.c
cvs diff -r1.65 -r1.66 src/sys/ddb/db_xxx.c (expand / switch to unified diff)

--- src/sys/ddb/db_xxx.c 2011/12/02 23:57:58 1.65
+++ src/sys/ddb/db_xxx.c 2011/12/03 16:25:49 1.66
@@ -1,14 +1,14 @@ @@ -1,14 +1,14 @@
1/* $NetBSD: db_xxx.c,v 1.65 2011/12/02 23:57:58 christos Exp $ */ 1/* $NetBSD: db_xxx.c,v 1.66 2011/12/03 16:25:49 christos Exp $ */
2 2
3/* 3/*
4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993
5 * The Regents of the University of California. All rights reserved. 5 * The Regents of the University of California. All rights reserved.
6 * 6 *
7 * Redistribution and use in source and binary forms, with or without 7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions 8 * modification, are permitted provided that the following conditions
9 * are met: 9 * are met:
10 * 1. Redistributions of source code must retain the above copyright 10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer. 11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright 12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the 13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution. 14 * documentation and/or other materials provided with the distribution.
@@ -27,27 +27,27 @@ @@ -27,27 +27,27 @@
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE. 29 * SUCH DAMAGE.
30 * 30 *
31 * from: kern_proc.c 8.4 (Berkeley) 1/4/94 31 * from: kern_proc.c 8.4 (Berkeley) 1/4/94
32 */ 32 */
33 33
34/* 34/*
35 * Miscellaneous DDB functions that are intimate (xxx) with various 35 * Miscellaneous DDB functions that are intimate (xxx) with various
36 * data structures and functions used by the kernel (proc, callout). 36 * data structures and functions used by the kernel (proc, callout).
37 */ 37 */
38 38
39#include <sys/cdefs.h> 39#include <sys/cdefs.h>
40__KERNEL_RCSID(0, "$NetBSD: db_xxx.c,v 1.65 2011/12/02 23:57:58 christos Exp $"); 40__KERNEL_RCSID(0, "$NetBSD: db_xxx.c,v 1.66 2011/12/03 16:25:49 christos Exp $");
41 41
42#ifdef _KERNEL_OPT 42#ifdef _KERNEL_OPT
43#include "opt_kgdb.h" 43#include "opt_kgdb.h"
44#include "opt_aio.h" 44#include "opt_aio.h"
45#include "opt_mqueue.h" 45#include "opt_mqueue.h"
46#endif 46#endif
47 47
48#ifndef _KERNEL 48#ifndef _KERNEL
49#include <stdbool.h> 49#include <stdbool.h>
50#endif 50#endif
51 51
52#include <sys/param.h> 52#include <sys/param.h>
53#include <sys/systm.h> 53#include <sys/systm.h>
@@ -98,39 +98,49 @@ db_kill_proc(db_expr_t addr, bool haddr, @@ -98,39 +98,49 @@ db_kill_proc(db_expr_t addr, bool haddr,
98 db_error("sig?\n"); 98 db_error("sig?\n");
99 /*NOTREACHED*/ 99 /*NOTREACHED*/
100 } 100 }
101 } else { 101 } else {
102 db_unread_token(t); 102 db_unread_token(t);
103 sig = 15; 103 sig = 15;
104 } 104 }
105 if (db_read_token() != tEOL) { 105 if (db_read_token() != tEOL) {
106 db_error("?\n"); 106 db_error("?\n");
107 /*NOTREACHED*/ 107 /*NOTREACHED*/
108 } 108 }
109 /* We might stop when the mutex is held or when not */ 109 /* We might stop when the mutex is held or when not */
110 t = mutex_tryenter(proc_lock); 110 t = mutex_tryenter(proc_lock);
 111#ifdef DIAGNOSTIC
 112 if (!t) {
 113 db_error("could not acquire proc_lock mutex\n");
 114 /*NOTREACHED*/
 115 }
 116#endif
111 p = proc_find((pid_t)pid); 117 p = proc_find((pid_t)pid);
112 if (t) 
113 mutex_exit(proc_lock); 
114 if (p == NULL) { 118 if (p == NULL) {
115 db_error("no such proc\n"); 119 if (t)
116 /*NOTREACHED*/ 120 mutex_exit(proc_lock);
 121 db_error("no such proc\n");
 122 /*NOTREACHED*/
117 } 123 }
118 KSI_INIT(&ksi); 124 KSI_INIT(&ksi);
119 ksi.ksi_signo = sig; 125 ksi.ksi_signo = sig;
120 ksi.ksi_code = SI_USER; 126 ksi.ksi_code = SI_USER;
121 ksi.ksi_pid = 0; 127 ksi.ksi_pid = 0;
122 ksi.ksi_uid = 0; 128 ksi.ksi_uid = 0;
 129 mutex_enter(p->p_lock);
123 kpsignal2(p, &ksi); 130 kpsignal2(p, &ksi);
 131 mutex_exit(p->p_lock);
 132 if (t)
 133 mutex_exit(proc_lock);
124#else 134#else
125 db_printf("This command is not currently supported.\n"); 135 db_printf("This command is not currently supported.\n");
126#endif 136#endif
127} 137}
128 138
129#ifdef KGDB 139#ifdef KGDB
130void 140void
131db_kgdb_cmd(db_expr_t addr, bool haddr, 141db_kgdb_cmd(db_expr_t addr, bool haddr,
132 db_expr_t count, const char *modif) 142 db_expr_t count, const char *modif)
133{ 143{
134 kgdb_active++; 144 kgdb_active++;
135 kgdb_trap(db_trap_type, DDB_REGS); 145 kgdb_trap(db_trap_type, DDB_REGS);
136 kgdb_active--; 146 kgdb_active--;