Date: Fri, 04 Jan 2002 18:44:36 +0300 From: "Vladimir B.Grebenschikov" <vova@sw.ru> To: FreeBSD-gnats-submit@freebsd.org Subject: bin/33537: savecore cannot save kernel core if it's size > 2Gb Message-ID: <E16MWWK-0001hP-00@vbook.express.ru>
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>Number: 33537
>Category: bin
>Synopsis: savecore cannot save kernel core if it's size > 2Gb
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Fri Jan 04 07:50:00 PST 2002
>Closed-Date:
>Last-Modified:
>Originator: Vladimir B. Grebenschikov
>Release: FreeBSD 5.0-CURRENT i386
>Organization:
SWsoft
>Environment:
System: FreeBSD vbook.express.ru 5.0-CURRENT FreeBSD 5.0-CURRENT #10: Fri Dec 28 19:17:02 MSK 2001 root@walder.asplinux.ru:/usr/obj/ext/current/src/sys/VBOOK i386
checked also on 4.4-RELEASE and RELENG_4
>Description:
Due to integer overflows and fseek overflow savecore can't save
kernel core on machine with more than 2Gb
Bug related to kern/33535 (but not depends on)
>How-To-Repeat:
# dumpon <some-big-enough-partition>
sysctl debug.enter_debugger=ddb
db> call dumpsys()
.... succeeded
db> c
# savecore /var/crash
# ls -l /var/crash
ls -l /var/crash/vmcore.?
total 0
-rw-r--r-- 1 root wheel 0 Jan 4 18:32 vmcore.0
#
There two problems in code:
- signed/unsigned integer overflow while counting size of corefile
- fseek problem (fseek cannot seek over 2 Gb boundary)
>Fix:
diff -u -r1.28.2.8 savecore.c
--- sbin/savecore/savecore.c 2001/08/01 09:04:22 1.28.2.8
+++ sbin/savecore/savecore.c 2002/01/04 15:15:40
@@ -221,7 +221,7 @@
int kmem, i;
const char *dump_sys;
size_t len;
- long kdumplo; /* block number where dump starts on dumpdev */
+ unsigned long kdumplo; /* block number where dump starts on dumpdev */
char *p;
/*
@@ -266,7 +266,7 @@
(void)Read(kmem, &kdumplo, sizeof(kdumplo));
dumplo = (off_t)kdumplo * DEV_BSIZE;
if (verbose)
- (void)printf("dumplo = %lld (%ld * %d)\n",
+ (void)printf("dumplo = %lld (%lu * %d)\n",
(long long)dumplo, kdumplo, DEV_BSIZE);
Lseek(kmem, (off_t)current_nl[X_DUMPMAG].n_value, L_SET);
(void)Read(kmem, &dumpmag, sizeof(dumpmag));
@@ -446,7 +446,7 @@
if (fwrite(buf + nw, hs - nw, 1, fp) != 1)
break;
if (he > hs)
- if (fseek(fp, he - hs, SEEK_CUR) == -1)
+ if (fseeko(fp, he - hs, SEEK_CUR) == -1)
break;
}
if (nw != nr) {
@@ -581,12 +581,12 @@
void
get_dumpsize()
{
- int kdumpsize;
+ unsigned int kdumpsize;
/* Read the dump size. */
DumpRead(dumpfd, &kdumpsize, sizeof(kdumpsize),
(off_t)(dumplo + ok(dump_nl[X_DUMPSIZE].n_value)), L_SET);
- dumpsize = kdumpsize * getpagesize();
+ dumpsize = kdumpsize * (unsigned)getpagesize();
}
/*
>Release-Note:
>Audit-Trail:
>Unformatted:
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