Messages in this thread Patch in this message |  | | Date | Fri, 21 Sep 2001 10:16:25 +0200 (CEST) | From | Matthias Hanisch <> | Subject | PATCH: fix for soundblaster module oops at rmmod time (fwd) |
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[ I sent this to linux-sound yesterday. Nerijus Baliunas <nerijus@users.sourceforge.net> asked me to forward this also to linux-kernel. So here it is. ]
Hi!
Soundblaster module in version 2.4.10-pre12 and many (pre-)patches before oopsed in sb_dsp_unload at the module deletion phase.
Loading the module reports
Sep 17 23:08:05 pingu kernel: <Sound Blaster (8 BIT/MONO ONLY) (2.01)> at 0x220 irq 5 dma 1>
so sb_mixer_init() is not called, because devc->major == 2.
Problem is that at "module deletion time", the call to sb_mixer_unload() is unconditional and a
kfree(mixer_devs[devc->my_mixerdev]);
is not very healthy if devc->my_mixerdev == -1 (the initial value).
This kfree() call without checking the array index got introduced in 2.4.8, sound_unload_mixerdev() which is called after kfree() contains a check for devc->my_mixerdev != -1.
The attached patch cures this, it just introduces this check. It should apply to any recent kernel.
Regards,
Matze
-- Matthias Hanisch mailto:matze@camline.com phone: +49 8137 935-219
diff -ru linux/drivers/sound/sb_mixer.c linux-matze/drivers/sound/sb_mixer.c --- linux/drivers/sound/sb_mixer.c Mon Sep 17 23:36:38 2001 +++ linux-matze/drivers/sound/sb_mixer.c Tue Sep 18 00:39:47 2001 @@ -748,6 +748,9 @@ void sb_mixer_unload(sb_devc *devc) { + if (devc->my_mixerdev == -1) + return; + kfree(mixer_devs[devc->my_mixerdev]); sound_unload_mixerdev(devc->my_mixerdev); sbmixnum--; |  |