d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Grrrr. Fix a really lame bug that I tripped over while testing my miibus

Browse Source 
stuff: unregister_methods() is horribly broken. The idea, if I'm not mistaken,
is that the refcount on a method is decremented, and only when it reaches
zero is the method freed. However desc->method is set to NULL unconditionally
regardless of the refcount, which means the method pointer is trashed the
first time the method is deallocated. The obvious detrimental effect is
that memory is leaked. The not so obvious effect is that when you call
unregister_method() the second time on the same method, you get a NULL
pointer dereference and a panic.

Now I can successfully unload network device drivers and the miibus module
without crashing the system.

*sigh*
This commit is contained in:
Bill Paul 1999-08-14 05:11:01 +00:00
parent efabbb14f9
commit b7f6c65f7c
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
sys/kern/subr_bus.c
View File

@ -23,7 +23,7 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: subr_bus.c,v 1.34 1999/08/11 22:05:17 peter Exp $
* $Id: subr_bus.c,v 1.35 1999/08/11 22:55:39 peter Exp $
*/
#include <sys/param.h>
@ -159,8 +159,8 @@ unregister_method(struct device_op_desc *desc)
if (m->refs == 0) {
LIST_REMOVE(m, link);
free(m, M_DEVBUF);
desc->method = 0;
}
desc->method = 0;
}
static int error_method(void)