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Work much harder at obtaining a correct device node. If what devname(3)

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returns doesn't exist, or doesn't match the desired device, fall back to
scanning /dev for a matching node, and as a last resort, if that fails,
try to create the node ourselves as /dev/dump.

Add comments to several variables and functions.

Clean up syslog(3) usage; use %m instead of strerror(3).

Other minor cleanup.
This commit is contained in:
Dag-Erling Smørgrav 2000-10-17 22:43:41 +00:00
parent a0951dd59e
commit c74e16f917
1 changed files with 89 additions and 31 deletions
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120
sbin/savecore/savecore.c
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@ -55,7 +55,7 @@ static const char rcsid[] =
#include <vm/vm_param.h> #include <vm/vm_param.h>
#include <vm/pmap.h> #include <vm/pmap.h>
#include <errno.h> #include <dirent.h>
#include <fcntl.h> #include <fcntl.h>
#include <nlist.h> #include <nlist.h>
#include <paths.h> #include <paths.h>
@ -106,15 +106,15 @@ off_t dumplo; /* where dump starts on dumpdev */
int dumpmag; /* magic number in dump */ int dumpmag; /* magic number in dump */
int dumpsize; /* amount of memory dumped */ int dumpsize; /* amount of memory dumped */
char *kernel; char *kernel; /* user-specified kernel */
char *savedir; /* directory to save dumps in */ char *savedir; /* directory to save dumps in */
char *ddname; /* name of dump device */ char ddname[MAXPATHLEN]; /* name of dump device */
dev_t dumpdev; /* dump device */ dev_t dumpdev; /* dump device */
int dumpfd; /* read/write descriptor on char dev */ int dumpfd; /* read/write descriptor on char dev */
time_t now; /* current date */ time_t now; /* current date */
char panic_mesg[1024]; char panic_mesg[1024]; /* panic message */
int panicstr; int panicstr; /* flag: dump was caused by panic */
char vers[1024]; char vers[1024]; /* version of kernel that crashed */
int clear, compress, force, verbose; /* flags */ int clear, compress, force, verbose; /* flags */
@ -124,7 +124,7 @@ void clear_dump __P((void));
void DumpRead __P((int fd, void *bp, int size, off_t off, int flag)); void DumpRead __P((int fd, void *bp, int size, off_t off, int flag));
void DumpWrite __P((int fd, void *bp, int size, off_t off, int flag)); void DumpWrite __P((int fd, void *bp, int size, off_t off, int flag));
int dump_exists __P((void)); int dump_exists __P((void));
char *find_dev __P((dev_t)); void find_dev __P((dev_t));
int get_crashtime __P((void)); int get_crashtime __P((void));
void get_dumpsize __P((void)); void get_dumpsize __P((void));
void kmem_setup __P((void)); void kmem_setup __P((void));
@ -226,8 +226,7 @@ kmem_setup()
* the same!) * the same!)
*/ */
if ((nlist(getbootfile(), current_nl)) == -1) if ((nlist(getbootfile(), current_nl)) == -1)
syslog(LOG_ERR, "%s: nlist: %s", getbootfile(), syslog(LOG_ERR, "%s: nlist: %m", getbootfile());
strerror(errno));
for (i = 0; cursyms[i] != -1; i++) for (i = 0; cursyms[i] != -1; i++)
if (current_nl[cursyms[i]].n_value == 0) { if (current_nl[cursyms[i]].n_value == 0) {
syslog(LOG_ERR, "%s: %s not in namelist", syslog(LOG_ERR, "%s: %s not in namelist",
@ -237,7 +236,7 @@ kmem_setup()
dump_sys = kernel ? kernel : getbootfile(); dump_sys = kernel ? kernel : getbootfile();
if ((nlist(dump_sys, dump_nl)) == -1) if ((nlist(dump_sys, dump_nl)) == -1)
syslog(LOG_ERR, "%s: nlist: %s", dump_sys, strerror(errno)); syslog(LOG_ERR, "%s: nlist: %m", dump_sys);
for (i = 0; dumpsyms[i] != -1; i++) for (i = 0; dumpsyms[i] != -1; i++)
if (dump_nl[dumpsyms[i]].n_value == 0) { if (dump_nl[dumpsyms[i]].n_value == 0) {
syslog(LOG_ERR, "%s: %s not in namelist", syslog(LOG_ERR, "%s: %s not in namelist",
@ -266,7 +265,7 @@ kmem_setup()
(long long)dumplo, kdumplo, DEV_BSIZE); (long long)dumplo, kdumplo, DEV_BSIZE);
Lseek(kmem, (off_t)current_nl[X_DUMPMAG].n_value, L_SET); Lseek(kmem, (off_t)current_nl[X_DUMPMAG].n_value, L_SET);
(void)Read(kmem, &dumpmag, sizeof(dumpmag)); (void)Read(kmem, &dumpmag, sizeof(dumpmag));
ddname = find_dev(dumpdev); find_dev(dumpdev);
dumpfd = Open(ddname, O_RDWR); dumpfd = Open(ddname, O_RDWR);
fp = fdopen(kmem, "r"); fp = fdopen(kmem, "r");
if (fp == NULL) { if (fp == NULL) {
@ -304,17 +303,24 @@ check_kmem()
} }
} }
/*
* Clear the magic number in the dump header.
*/
void void
clear_dump() clear_dump()
{ {
long newdumplo; int newdumpmag;
newdumplo = 0; newdumpmag = 0;
DumpWrite(dumpfd, &newdumplo, sizeof(newdumplo), DumpWrite(dumpfd, &newdumpmag, sizeof(newdumpmag),
(off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET); (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), L_SET);
close(dumpfd); close(dumpfd);
} }
/*
* Check if a dump exists by looking for a magic number in the dump
* header.
*/
int int
dump_exists() dump_exists()
{ {
@ -334,6 +340,9 @@ dump_exists()
char buf[1024 * 1024]; char buf[1024 * 1024];
/*
* Save the core dump.
*/
void void
save_core() save_core()
{ {
@ -351,7 +360,7 @@ save_core()
goto err1; goto err1;
if (fgets(buf, sizeof(buf), fp) == NULL) { if (fgets(buf, sizeof(buf), fp) == NULL) {
if (ferror(fp)) if (ferror(fp))
err1: syslog(LOG_WARNING, "%s: %s", path, strerror(errno)); err1: syslog(LOG_WARNING, "%s: %m", path);
bounds = 0; bounds = 0;
} else } else
bounds = atoi(buf); bounds = atoi(buf);
@ -373,7 +382,7 @@ err1: syslog(LOG_WARNING, "%s: %s", path, strerror(errno));
else else
fp = fopen(path, "w"); fp = fopen(path, "w");
if (fp == NULL) { if (fp == NULL) {
syslog(LOG_ERR, "%s: %s", path, strerror(errno)); syslog(LOG_ERR, "%s: %m", path);
exit(1); exit(1);
} }
(void)umask(oumask); (void)umask(oumask);
@ -398,8 +407,7 @@ err1: syslog(LOG_WARNING, "%s: %s", path, strerror(errno));
} }
nw = fwrite(buf, 1, nr, fp); nw = fwrite(buf, 1, nr, fp);
if (nw != nr) { if (nw != nr) {
syslog(LOG_ERR, "%s: %s", syslog(LOG_ERR, "%s: %m", path);
path, strerror(nw == 0 ? EIO : errno));
err2: syslog(LOG_WARNING, err2: syslog(LOG_WARNING,
"WARNING: vmcore may be incomplete"); "WARNING: vmcore may be incomplete");
(void)printf("\n"); (void)printf("\n");
@ -418,7 +426,7 @@ err2: syslog(LOG_WARNING,
else else
fp = fopen(path, "w"); fp = fopen(path, "w");
if (fp == NULL) { if (fp == NULL) {
syslog(LOG_ERR, "%s: %s", path, strerror(errno)); syslog(LOG_ERR, "%s: %m", path);
exit(1); exit(1);
} }
syslog(LOG_NOTICE, "writing %skernel to %s", syslog(LOG_NOTICE, "writing %skernel to %s",
@ -426,16 +434,14 @@ err2: syslog(LOG_WARNING,
while ((nr = read(ifd, buf, sizeof(buf))) > 0) { while ((nr = read(ifd, buf, sizeof(buf))) > 0) {
nw = fwrite(buf, 1, nr, fp); nw = fwrite(buf, 1, nr, fp);
if (nw != nr) { if (nw != nr) {
syslog(LOG_ERR, "%s: %s", syslog(LOG_ERR, "%s: %m", path);
path, strerror(nw == 0 ? EIO : errno));
syslog(LOG_WARNING, syslog(LOG_WARNING,
"WARNING: kernel may be incomplete"); "WARNING: kernel may be incomplete");
exit(1); exit(1);
} }
} }
if (nr < 0) { if (nr < 0) {
syslog(LOG_ERR, "%s: %s", syslog(LOG_ERR, "%s: %m", kernel ? kernel : getbootfile());
kernel ? kernel : getbootfile(), strerror(errno));
syslog(LOG_WARNING, syslog(LOG_WARNING,
"WARNING: kernel may be incomplete"); "WARNING: kernel may be incomplete");
exit(1); exit(1);
@ -444,22 +450,67 @@ err2: syslog(LOG_WARNING,
close(ifd); close(ifd);
} }
char * /*
* Verify that the specified device node exists and matches the
* specified device.
*/
int
verify_dev(name, dev)
char *name;
register dev_t dev;
{
struct stat sb;
if (lstat(name, &sb) == -1)
return (-1);
if (!S_ISCHR(sb.st_mode) || sb.st_rdev != dev)
return (-1);
return (0);
}
/*
* Find the dump device.
*
* 1) try devname(3); see if it returns something sensible
* 2) scan /dev for the desired node
* 3) as a last resort, try to create the node we need
*/
void
find_dev(dev) find_dev(dev)
register dev_t dev; register dev_t dev;
{ {
char *dn; struct dirent *ent;
char *dn, *dnp;
DIR *d;
strcpy(ddname, _PATH_DEV);
dnp = ddname + sizeof _PATH_DEV - 1;
if ((dn = devname(dev, S_IFCHR)) != NULL) { if ((dn = devname(dev, S_IFCHR)) != NULL) {
if (asprintf(&dn, "/dev/%s", dn) != -1) strcpy(dnp, dn);
return dn; if (verify_dev(ddname, dev) == 0)
syslog(LOG_ERR, "insufficient memory"); return;
} else {
syslog(LOG_ERR, "can't find device %d/%d", major(dev), minor(dev));
} }
if ((d = opendir(_PATH_DEV)) != NULL) {
while ((ent = readdir(d))) {
strcpy(dnp, ent->d_name);
if (verify_dev(ddname, dev) == 0) {
closedir(d);
return;
}
}
closedir(d);
}
strcpy(dnp, "dump");
if (mknod(ddname, S_IFCHR|S_IRUSR|S_IWUSR, dev) == 0)
return;
syslog(LOG_ERR, "can't find device %d/%#x", major(dev), minor(dev));
exit(1); exit(1);
} }
/*
* Extract the date and time of the crash from the dump header, and
* make sure it looks sane (within one week of current date and time).
*/
int int
get_crashtime() get_crashtime()
{ {
@ -481,6 +532,9 @@ get_crashtime()
return (1); return (1);
} }
/*
* Extract the size of the dump from the dump header.
*/
void void
get_dumpsize() get_dumpsize()
{ {
@ -490,6 +544,10 @@ get_dumpsize()
dumpsize *= getpagesize(); dumpsize *= getpagesize();
} }
/*
* Check that sufficient space is available on the disk that holds the
* save directory.
*/
int int
check_space() check_space()
{ {
@ -658,7 +716,7 @@ Write(fd, bp, size)
int n; int n;
if ((n = write(fd, bp, size)) < size) { if ((n = write(fd, bp, size)) < size) {
syslog(LOG_ERR, "write: %s", strerror(n == -1 ? errno : EIO)); syslog(LOG_ERR, "write: %m");
exit(1); exit(1);
} }
} }