ALSA: opti9xx: Fix conflicting driver object name
Takashi Iwai [Tue, 27 Aug 2013 10:03:01 +0000 (12:03 +0200)]
commit fb615499f0ad28ed74201c1cdfddf9e64e205424 upstream.

The recent commit to delay the release of kobject triggered NULL
dereferences of opti9xx drivers.  The cause is that all
snd-opti92x-ad1848, snd-opti92x-cs4231 and snd-opti93x drivers
register the PnP card driver with the very same name, and also
snd-opti92x-ad1848 and -cs4231 drivers register the ISA driver with
the same name, too.  When these drivers are built in, quick
"register-release-and-re-register" actions occur, and this results in
Oops because of the same name is assigned to the kobject.

The fix is simply to assign individual names.  As a bonus, by using
KBUILD_MODNAME, the patch reduces more lines than it adds.

The fix is based on the suggestion by Russell King.

Reported-and-tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

sound/isa/opti9xx/opti92x-ad1848.c

index b41ed86..e427dbf 100644 (file)
@@ -173,11 +173,7 @@ MODULE_DEVICE_TABLE(pnp_card, snd_opti9xx_pnpids);
 
 #endif /* CONFIG_PNP */
 
-#ifdef OPTi93X
-#define DEV_NAME "opti93x"
-#else
-#define DEV_NAME "opti92x"
-#endif
+#define DEV_NAME KBUILD_MODNAME
 
 static char * snd_opti9xx_names[] = {
        "unknown",
@@ -1168,7 +1164,7 @@ static int snd_opti9xx_pnp_resume(struct pnp_card_link *pcard)
 
 static struct pnp_card_driver opti9xx_pnpc_driver = {
        .flags          = PNP_DRIVER_RES_DISABLE,
-       .name           = "opti9xx",
+       .name           = DEV_NAME,
        .id_table       = snd_opti9xx_pnpids,
        .probe          = snd_opti9xx_pnp_probe,
        .remove         = snd_opti9xx_pnp_remove,