Properly lock accesses to p_tracep and p_traceflag. Also make a few

ktrace-only things #ifdef KTRACE that were not before.

3 files changed, 27 insertions, 3 deletions

diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index f3a24c8..913f951 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -135,7 +135,10 @@ execve(td, uap)
 	int (*img_first)(struct image_params *);
 	struct pargs *oldargs, *newargs = NULL;
 	struct procsig *oldprocsig, *newprocsig;
-	struct vnode *tracevp = NULL, *textvp = NULL;
+#ifdef KTRACE
+	struct vnode *tracevp = NULL;
+#endif
+	struct vnode *textvp = NULL;
 
 	imgp = &image_params;
 
@@ -369,11 +372,15 @@ interpret:
 		 * we do not regain any tracing during a possible block.
 		 */
 		setsugid(p);
+#ifdef KTRACE
 		if (p->p_tracep && suser_cred(oldcred, PRISON_ROOT)) {
+			mtx_lock(&ktrace_mtx);
 			p->p_traceflag = 0;
 			tracevp = p->p_tracep;
 			p->p_tracep = NULL;
+			mtx_unlock(&ktrace_mtx);
 		}
+#endif
 		/* Make sure file descriptors 0..2 are in use.  */
 		error = fdcheckstd(td);
 		if (error != 0)
@@ -475,8 +482,10 @@ interpret:
 	 */
 	if (textvp != NULL)
 		vrele(textvp);
+#ifdef KTRACE
 	if (tracevp != NULL)
 		vrele(tracevp);
+#endif
 	pargs_drop(oldargs);
 
 exec_fail_dealloc:
diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index d44209a..d35b3e1 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -64,6 +64,9 @@
 #include <sys/shm.h>
 #include <sys/sem.h>
 #include <sys/jail.h>
+#ifdef KTRACE
+#include <sys/ktrace.h>
+#endif
 
 #include <vm/vm.h>
 #include <vm/vm_extern.h>
@@ -296,9 +299,11 @@ exit1(td, rv)
 	 * release trace file
 	 */
 	PROC_LOCK(p);
+	mtx_lock(&ktrace_mtx);
 	p->p_traceflag = 0;	/* don't trace the vrele() */
 	tracevp = p->p_tracep;
 	p->p_tracep = NULL;
+	mtx_unlock(&ktrace_mtx);
 	PROC_UNLOCK(p);
 	if (tracevp != NULL)
 		vrele(tracevp);
diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index ebef4a6..1f48fa8 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -34,6 +34,8 @@
  * $FreeBSD$
  */
 
+#include "opt_ktrace.h"
+
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
@@ -49,6 +51,10 @@
 #include <sys/sx.h>
 #include <sys/user.h>
 #include <sys/jail.h>
+#ifdef KTRACE
+#include <sys/uio.h>
+#include <sys/ktrace.h>
+#endif
 
 #include <vm/vm.h>
 #include <vm/pmap.h>
@@ -643,8 +649,13 @@ fill_kinfo_proc(p, kp)
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	kp->ki_addr =/* p->p_addr; */0; /* XXXKSE */
 	kp->ki_args = p->p_args;
-	kp->ki_tracep = p->p_tracep;
 	kp->ki_textvp = p->p_textvp;
+#ifdef KTRACE
+	kp->ki_tracep = p->p_tracep;
+	mtx_lock(&ktrace_mtx);
+	kp->ki_traceflag = p->p_traceflag;
+	mtx_unlock(&ktrace_mtx);
+#endif
 	kp->ki_fd = p->p_fd;
 	kp->ki_vmspace = p->p_vmspace;
 	if (p->p_ucred) {
@@ -696,7 +707,6 @@ fill_kinfo_proc(p, kp)
 	kp->ki_stat = p->p_stat;
 	kp->ki_sflag = p->p_sflag;
 	kp->ki_swtime = p->p_swtime;
-	kp->ki_traceflag = p->p_traceflag;
 	kp->ki_pid = p->p_pid;
 	/* vvv XXXKSE */
 	bintime2timeval(&p->p_runtime, &tv);