On Tue, Apr 24, 2018 at 09:57:29PM +0200, Kirill Marinushkin wrote: > In the current implementation, vchi_instance is inited during the first > call of bcm2835_audio_open_connection(), and is never freed. It causes a > memory leak when the module `snd_bcm2835` is removed. > > Here is how this commit fixes it: > > * the VCHI context (including vchi_instance) is created once in the > platform's devres > * the VCHI context is allocated and connected once during module_init() > * all created bcm2835_chips have a pointer to this VCHI context > * bcm2835_audio_open_connection() can access the VCHI context through the > associated bcm2835_chip > * the VCHI context is disconnected and freed once during module_exit() > > After this commit is applied, I don't see other issues with the module's > init/exit, so I also remove the associated TODO task. > > Steps to reproduce the memory leak before this commit: > > ~~~~ > root@raspberrypi:/home/pi# aplay test0.wav > Playing WAVE 'test0.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Ster > ^CAborted by signal Interrupt... > root@raspberrypi:/home/pi# rmmod snd_bcm2835 > root@raspberrypi:/home/pi# modprobe snd_bcm2835 > root@raspberrypi:/home/pi# aplay test0.wav > Playing WAVE 'test0.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Ster > ^CAborted by signal Interrupt... > root@raspberrypi:/home/pi# echo scan > /sys/kernel/debug/kmemleak > root@raspberrypi:/home/pi# cat /sys/kernel/debug/kmemleak > unreferenced object 0xb6794c00 (size 128): > comm "aplay", pid 406, jiffies 36870 (age 116.650s) > hex dump (first 32 bytes): > 08 a5 82 81 01 00 00 00 08 4c 79 b6 08 4c 79 b6 .........Ly..Ly. > 00 00 00 00 00 00 00 00 ad 4e ad de ff ff ff ff .........N...... > backtrace: > [<802af5e0>] kmem_cache_alloc_trace+0x294/0x3d0 > [<806ce620>] vchiq_initialise+0x98/0x1b0 > [<806d0b34>] vchi_initialise+0x24/0x34 > [<7f1311ec>] 0x7f1311ec > [<7f1303bc>] 0x7f1303bc > [<7f130590>] 0x7f130590 > [<7f111fd8>] snd_pcm_open_substream+0x68/0xc4 [snd_pcm] > [<7f112108>] snd_pcm_open+0xd4/0x248 [snd_pcm] > [<7f112334>] snd_pcm_playback_open+0x4c/0x6c [snd_pcm] > [<7f0e250c>] snd_open+0xa8/0x14c [snd] > [<802ce590>] chrdev_open+0xac/0x188 > [<802c57b4>] do_dentry_open+0x10c/0x314 > [<802c6ba8>] vfs_open+0x5c/0x88 > [<802d9a68>] path_openat+0x368/0x944 > [<802dacd4>] do_filp_open+0x70/0xc4 > [<802c6f70>] do_sys_open+0x110/0x1d4 > ~~~~ > > Signed-off-by: Kirill Marinushkin <k.marinushkin@xxxxxxxxx> > Cc: Eric Anholt <eric@xxxxxxxxxx> > Cc: Stefan Wahren <stefan.wahren@xxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: Florian Fainelli <f.fainelli@xxxxxxxxx> > Cc: Ray Jui <rjui@xxxxxxxxxxxx> > Cc: Scott Branden <sbranden@xxxxxxxxxxxx> > Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > Cc: bcm-kernel-feedback-list@xxxxxxxxxxxx > Cc: linux-rpi-kernel@xxxxxxxxxxxxxxxxxxx > Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Cc: devel@xxxxxxxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > --- > .../vc04_services/bcm2835-audio/bcm2835-vchiq.c | 64 +++++++++++++--------- > .../staging/vc04_services/bcm2835-audio/bcm2835.c | 43 ++++++++++++++- > .../staging/vc04_services/bcm2835-audio/bcm2835.h | 12 ++++ > 3 files changed, 91 insertions(+), 28 deletions(-) What changed from v1? Always put that below the --- line as the documentation says to do so. v3? :) thanks, greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
