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Fixed corruption of the "blocked" list in lf_setlock() when tsleep()

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returns 0 after ptrace() attach and/or detach doesn't quite quite
deliver a signal.  Perhaps the process shouldn't be woken in this
case, but avoiding the problem is easy.

PR:		12247

Fixed a couple of places where mechanical fixing of compiler warnings
caused misspelling of NOLOCKF as NULL.
This commit is contained in:
Bruce Evans 1999-07-04 14:43:01 +00:00
parent 6d0cab6541
commit 1168ab0815
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=48556
1 changed files with 20 additions and 17 deletions
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37
sys/kern/kern_lockf.c
View File

@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* @(#)ufs_lockf.c 8.3 (Berkeley) 1/6/94
* $Id: kern_lockf.c,v 1.21 1999/01/27 21:49:56 dillon Exp $
* $Id: kern_lockf.c,v 1.22 1999/05/08 22:46:46 dt Exp $
*/
#include "opt_debug_lockf.h"
@ -272,20 +272,22 @@ lf_setlock(lock)
lf_printlist("lf_setlock", block);
}
#endif /* LOCKF_DEBUG */
if ((error = tsleep((caddr_t)lock, priority, lockstr, 0))) {
/*
* We may have been awakened by a signal (in
* which case we must remove ourselves from the
* blocked list) and/or by another process
* releasing a lock (in which case we have already
* been removed from the blocked list and our
* lf_next field set to NOLOCKF).
*/
if (lock->lf_next)
TAILQ_REMOVE(&lock->lf_next->lf_blkhd, lock,
lf_block);
free(lock, M_LOCKF);
return (error);
error = tsleep((caddr_t)lock, priority, lockstr, 0);
/*
* We may have been awakened by a signal and/or by a
* debugger continuing us (in which cases we must remove
* ourselves from the blocked list) and/or by another
* process releasing a lock (in which case we have
* already been removed from the blocked list and our
* lf_next field set to NOLOCKF).
*/
if (lock->lf_next) {
TAILQ_REMOVE(&lock->lf_next->lf_blkhd, lock, lf_block);
lock->lf_next = NOLOCKF;
}
if (error) {
free(lock, M_LOCKF);
return (error);
}
}
/*
@ -360,7 +362,8 @@ lf_setlock(lock)
overlap->lf_type == F_WRLCK) {
lf_wakelock(overlap);
} else {
while ((ltmp = overlap->lf_blkhd.tqh_first) != NULL) {
while ((ltmp = overlap->lf_blkhd.tqh_first) !=
NOLOCKF) {
TAILQ_REMOVE(&overlap->lf_blkhd, ltmp,
lf_block);
TAILQ_INSERT_TAIL(&lock->lf_blkhd,
@ -718,7 +721,7 @@ lf_wakelock(listhead)
{
register struct lockf *wakelock;
while ((wakelock = listhead->lf_blkhd.tqh_first) != NULL) {
while ((wakelock = listhead->lf_blkhd.tqh_first) != NOLOCKF) {
TAILQ_REMOVE(&listhead->lf_blkhd, wakelock, lf_block);
wakelock->lf_next = NOLOCKF;
#ifdef LOCKF_DEBUG