Module Name: src
Committed By: dholland
Date: Mon Aug 28 04:57:11 UTC 2017
Modified Files:
src/sys/kern: kern_ktrace.c
Log Message:
If we go to allocate and find someone else has at the same time, don't
trigger a refcount leak of the other guy's object. From mjg@freebsd.
While here also remove a bogus use of lbolt on the same path.
To generate a diff of this commit:
cvs rdiff -u -r1.171 -r1.172 src/sys/kern/kern_ktrace.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/kern_ktrace.c
diff -u src/sys/kern/kern_ktrace.c:1.171 src/sys/kern/kern_ktrace.c:1.172
--- src/sys/kern/kern_ktrace.c:1.171 Fri Jul 28 15:16:39 2017
+++ src/sys/kern/kern_ktrace.c Mon Aug 28 04:57:11 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_ktrace.c,v 1.171 2017/07/28 15:16:39 riastradh Exp $ */
+/* $NetBSD: kern_ktrace.c,v 1.172 2017/08/28 04:57:11 dholland Exp $ */
/*-
* Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -61,7 +61,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_ktrace.c,v 1.171 2017/07/28 15:16:39 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_ktrace.c,v 1.172 2017/08/28 04:57:11 dholland Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -985,7 +985,7 @@ ktrace_common(lwp_t *curl, int ops, int
{
struct proc *p;
struct pgrp *pg;
- struct ktr_desc *ktd = NULL;
+ struct ktr_desc *ktd = NULL, *nktd;
file_t *fp = *fpp;
int ret = 0;
int error = 0;
@@ -1015,22 +1015,22 @@ ktrace_common(lwp_t *curl, int ops, int
ktd = ktd_lookup(fp);
mutex_exit(&ktrace_lock);
if (ktd == NULL) {
- ktd = kmem_alloc(sizeof(*ktd), KM_SLEEP);
- TAILQ_INIT(&ktd->ktd_queue);
- callout_init(&ktd->ktd_wakch, CALLOUT_MPSAFE);
- cv_init(&ktd->ktd_cv, "ktrwait");
- cv_init(&ktd->ktd_sync_cv, "ktrsync");
- ktd->ktd_flags = 0;
- ktd->ktd_qcount = 0;
- ktd->ktd_error = 0;
- ktd->ktd_errcnt = 0;
- ktd->ktd_delayqcnt = ktd_delayqcnt;
- ktd->ktd_wakedelay = mstohz(ktd_wakedelay);
- ktd->ktd_intrwakdl = mstohz(ktd_intrwakdl);
- ktd->ktd_ref = 0;
- ktd->ktd_fp = fp;
+ nktd = kmem_alloc(sizeof(*nktd), KM_SLEEP);
+ TAILQ_INIT(&nktd->ktd_queue);
+ callout_init(&nktd->ktd_wakch, CALLOUT_MPSAFE);
+ cv_init(&nktd->ktd_cv, "ktrwait");
+ cv_init(&nktd->ktd_sync_cv, "ktrsync");
+ nktd->ktd_flags = 0;
+ nktd->ktd_qcount = 0;
+ nktd->ktd_error = 0;
+ nktd->ktd_errcnt = 0;
+ nktd->ktd_delayqcnt = ktd_delayqcnt;
+ nktd->ktd_wakedelay = mstohz(ktd_wakedelay);
+ nktd->ktd_intrwakdl = mstohz(ktd_intrwakdl);
+ nktd->ktd_ref = 0;
+ nktd->ktd_fp = fp;
mutex_enter(&ktrace_lock);
- ktdref(ktd);
+ ktdref(nktd);
mutex_exit(&ktrace_lock);
/*
@@ -1038,16 +1038,16 @@ ktrace_common(lwp_t *curl, int ops, int
* whether ktruss or ktrace.
*/
if (fp->f_type == DTYPE_PIPE)
- ktd->ktd_flags |= KTDF_INTERACTIVE;
+ nktd->ktd_flags |= KTDF_INTERACTIVE;
mutex_enter(&fp->f_lock);
fp->f_count++;
mutex_exit(&fp->f_lock);
error = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
- ktrace_thread, ktd, &ktd->ktd_lwp, "ktrace");
+ ktrace_thread, nktd, &nktd->ktd_lwp, "ktrace");
if (error != 0) {
- kmem_free(ktd, sizeof(*ktd));
- ktd = NULL;
+ kmem_free(nktd, sizeof(*nktd));
+ nktd = NULL;
mutex_enter(&fp->f_lock);
fp->f_count--;
mutex_exit(&fp->f_lock);
@@ -1055,16 +1055,15 @@ ktrace_common(lwp_t *curl, int ops, int
}
mutex_enter(&ktrace_lock);
- if (ktd_lookup(fp) != NULL) {
- ktdrel(ktd);
- ktd = NULL;
- } else
- TAILQ_INSERT_TAIL(&ktdq, ktd, ktd_list);
- if (ktd == NULL)
- cv_wait(&lbolt, &ktrace_lock);
+ ktd = ktd_lookup(fp);
+ if (ktd != NULL) {
+ ktdrel(nktd);
+ nktd = NULL;
+ } else {
+ TAILQ_INSERT_TAIL(&ktdq, nktd, ktd_list);
+ ktd = nktd;
+ }
mutex_exit(&ktrace_lock);
- if (ktd == NULL)
- goto done;
}
break;
