kern/84684: [PATCH] Kernel panic in kern_proc.c

[Antoine Pelisse]

>Number:         84684
>Category:       kern
>Synopsis:       [PATCH] Kernel panic in kern_proc.c
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Aug 08 20:40:13 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator:     Antoine Pelisse
>Release:        FreeBSD 7.0-CURRENT i386
>Organization:
Xloling	
>Environment:
System: FreeBSD hellmuth.xloling.org 7.0-CURRENT FreeBSD 7.0-CURRENT #21: Mon Aug 8 15:06:49 CEST 2005 i386
>Description:
	Fix for kernel panics:
	http://people.freebsd.org/~pho/stress/log/cons149.html
	http://people.freebsd.org/~pho/stress/log/cons130.html

>How-To-Repeat:
>Fix:

--- sys/kern/kern_proc.c.orig   Mon Apr 18 04:10:36 2005
+++ sys/kern/kern_proc.c        Mon Aug  8 22:00:27 2005
@@ -868,7 +868,7 @@
 {
        struct thread *td;
        struct kinfo_proc kinfo_proc;
-       int error = 0;
+       int error, buffersize = 0;
        struct proc *np;
        pid_t pid = p->p_pid;
 
@@ -883,11 +883,23 @@
        } else {
                _PHOLD(p);
                FOREACH_THREAD_IN_PROC(p, td) {
+                       buffersize += sizeof(struct kinfo_proc);
+               }
+               PROC_UNLOCK(p);
+
+               buffersize += 5 * sizeof(struct kinfo_proc);
+               error = sysctl_wire_old_buffer(req, buffersize);
+               if (error) {
+                       _PRELE(p);
+                       return error;
+               }
+
+               PROC_LOCK(p);
+               FOREACH_THREAD_IN_PROC(p, td) {
                        fill_kinfo_thread(td, &kinfo_proc);
-                       PROC_UNLOCK(p);
                        error = SYSCTL_OUT(req, (caddr_t)&kinfo_proc,
                                           sizeof(kinfo_proc));
-                       PROC_LOCK(p);
+
                        if (error)
                                break;
                }
>Release-Note:
>Audit-Trail:
>Unformatted: