Date: Fri, 27 Sep 2002 20:36:52 +0200 (CEST) From: Aurélien Nephtali <aurelien.nephtali@wanadoo.fr> To: FreeBSD-gnats-submit@FreeBSD.org Subject: bin/43434: New option to 'dmesg' which allow to display or not old boot messages Message-ID: <200209271836.g8RIaqVo091644@nebula.wanadoo.fr>
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>Number: 43434
>Category: bin
>Synopsis: New option to 'dmesg' which allow to display or not old boot messages
>Confidential: no
>Severity: critical
>Priority: high
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: change-request
>Submitter-Id: current-users
>Arrival-Date: Fri Sep 27 11:40:01 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator: dak
>Release: FreeBSD 4.7-RC i386
>Organization:
none
>Environment:
System: FreeBSD nebula.wanadoo.fr 4.7-RC FreeBSD 4.7-RC #168: Fri Sep 27 07:44:50 CEST 2002 dak@nebula.wanadoo.fr:/usr/src/sys/compile/NEBULA i386
>Description:
Some times it could be usefull to display only the last boot message (ie: when grep'ing).
The attached patch modifies sys/kern/subr_prf.c and dmesg.c (and the also the manual).
It adds a tag (---<<<BOOT>>>---) at the begining of each boot message (the tag
macro is stored in sys/sys/msgbuf.h and could also be stored in /usr/include/msgbuf.h)
dmesg.c is modified and has a new option: -o, which when it is specified, displays the full
content of the message buffer, otherwise only the last message is displayed).
This patch has been tested (by me :p) without any troubles on -CURRENT.
>How-To-Repeat:
>Fix:
--- current.patch begins here ---
--- sbin/dmesg/dmesg.c Sun Aug 18 19:57:07 2002
+++ sbin/dmesg/dmesg.c Sun Sep 15 20:12:42 2002
@@ -66,12 +66,35 @@
{ NULL },
};
+int getlastbootpos(char *buf, int len);
void usage(void) __dead2;
#define KREAD(addr, var) \
kvm_read(kd, addr, &var, sizeof(var)) != sizeof(var)
int
+getlastbootpos(char *buf, int len)
+{
+ int i;
+ char *ptr, *save;
+
+ /* Skip NULL bytes */
+ for(i = 0; (buf[i] == 0x0) && (i < len); i++);
+
+ if (strlen(buf) == 0)
+ return(-1);
+
+ while((ptr = (char *) strstr((buf +i), BOOT_TAG)) != NULL) {
+ save = (char *) ptr;
+ i += strlen(BOOT_TAG); /* Force strstr() to catch
+ * the next tag
+ */
+ }
+
+ return((int) ((int) (save + (strlen(BOOT_TAG))) - (int) buf));
+}
+
+int
main(int argc, char *argv[])
{
int ch, newl, skip;
@@ -84,10 +107,12 @@
int pri;
size_t buflen;
int bufpos;
+ int old = 0;
+ int lastboot = 0;
(void) setlocale(LC_CTYPE, "");
memf = nlistf = NULL;
- while ((ch = getopt(argc, argv, "aM:N:")) != -1)
+ while ((ch = getopt(argc, argv, "aM:N:o")) != -1)
switch(ch) {
case 'a':
all++;
@@ -98,6 +123,9 @@
case 'N':
nlistf = optarg;
break;
+ case 'o':
+ old = 1;
+ break;
case '?':
default:
usage();
@@ -151,11 +179,19 @@
* we effectively start at the oldest data.
*/
p = bp + bufpos;
+ if (!old) {
+ lastboot = getlastbootpos(p, buflen);
+ if (lastboot != -1)
+ p = bp + lastboot;
+ }
ep = (bufpos == 0 ? bp + buflen : p);
newl = skip = 0;
do {
if (p == bp + buflen)
p = bp;
+ /* Skipping boot tag */
+ if (!memcmp(p, BOOT_TAG, strlen(BOOT_TAG)))
+ p += strlen(BOOT_TAG);
ch = *p;
/* Skip "\n<.*>" syslog sequences. */
if (skip) {
@@ -193,6 +229,6 @@
void
usage(void)
{
- (void)fprintf(stderr, "usage: dmesg [-a] [-M core] [-N system]\n");
+ (void)fprintf(stderr, "usage: dmesg [-a] [-M core] [-N system] [-o]\n");
exit(1);
}
--- sbin/dmesg/dmesg.8 Sat Aug 31 21:15:54 2002
+++ sbin/dmesg/dmesg.8 Sat Aug 31 20:57:27 2002
@@ -43,6 +43,7 @@
.Op Fl a
.Op Fl M Ar core
.Op Fl N Ar system
+.Op Fl o
.Sh DESCRIPTION
The
.Nm
@@ -73,6 +74,8 @@
.It Fl N
Extract the name list from the specified system instead of the default,
which is the kernel image the system has booted from.
+.It Fl o
+Display all boot messages, not only the last.
.El
.Sh FILES
.Bl -tag -width ".Pa /var/run/dmesg.boot" -compact
--- sys/sys/msgbuf.h Sat Aug 31 21:07:05 2002
+++ sys/sys/msgbuf.h Sat Aug 31 21:08:40 2002
@@ -46,6 +46,10 @@
char * msg_ptr; /* pointer to buffer */
};
+#define BOOT_TAG "---<<BOOT>>---" /* used by dmesg util to know where a
+ * boot message starts.
+ */
+
#ifdef _KERNEL
extern int msgbuftrigger;
extern struct msgbuf *msgbufp;
--- sys/kern/subr_prf.c Sat Aug 31 21:00:35 2002
+++ sys/kern/subr_prf.c Sat Aug 31 21:01:01 2002
@@ -818,6 +818,9 @@
msgbufp->msg_size = (char *)msgbufp - cp;
}
msgbufp->msg_ptr = cp;
+ memcpy((void *) (msgbufp->msg_ptr + msgbufp->msg_bufx), BOOT_TAG,
+ strlen(BOOT_TAG));
+ msgbufp->msg_bufx += strlen(BOOT_TAG);
if (msgbufmapped && oldp != msgbufp)
msgbufcopy(oldp);
msgbufmapped = 1;
--- current.patch ends here ---
>Release-Note:
>Audit-Trail:
>Unformatted:
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