threads/144558: Repeated calls to __rpc_createerr allocates multiple thread-specific data slots

[Sam Robb]

>Number:         144558
>Category:       threads
>Synopsis:       Repeated calls to __rpc_createerr allocates multiple thread-specific data slots
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-threads
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Mar 08 18:00:16 UTC 2010
>Closed-Date:
>Last-Modified:
>Originator:     Sam Robb
>Release:        7.1
>Organization:
Avere Systems
>Environment:
FreeBSD build1.arriad.com 7.1-RELEASE FreeBSD 7.1-RELEASE #0: Thu Jan  1 08:58:24 UTC 2009     root at driscoll.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  amd64
>Description:
On the first call to __rpc_createerr() in a thread, the function attempts to allocate a thread-specific slot to hold the rpc error data.  Subsequent calls from the same thread continue to allocate new thread-specific slots without freeing the first, so that repeated calls eventually result in all available thread-specific data slots being allocated.

>How-To-Repeat:

>Fix:
Patch attached

Patch attached with submission follows:

--- a/src/lib/libc/rpc/mt_misc.c
+++ b/src/lib/libc/rpc/mt_misc.c
@@ -89,15 +89,16 @@ struct rpc_createerr rpc_createerr;
 struct rpc_createerr *
 __rpc_createerr()
 {
-	static thread_key_t rce_key = 0;
+	static thread_key_t rce_key = -1;
 	struct rpc_createerr *rce_addr = 0;
 
 	if (thr_main())
 		return (&rpc_createerr);
 	if ((rce_addr =
-	    (struct rpc_createerr *)thr_getspecific(rce_key)) != 0) {
+	    (struct rpc_createerr *)thr_getspecific(rce_key)) == 0) {
 		mutex_lock(&tsd_lock);
-		if (thr_keycreate(&rce_key, free) != 0) {
+		if ((rce_key == -1) && 
+		    (thr_keycreate(&rce_key, free) != 0)) {
 			mutex_unlock(&tsd_lock);
 			return (&rpc_createerr);
 		}


>Release-Note:
>Audit-Trail:
>Unformatted: