From mboxrd@z Thu Jan 1 00:00:00 1970 From: k.marinushkin@gmail.com (Kirill Marinushkin) Date: Wed, 25 Apr 2018 19:35:25 +0200 Subject: [PATCH v2] staging: bcm2835-audio: Disconnect and free vchi_instance on module_exit() In-Reply-To: <20180425061638.GA1450@kroah.com> References: <9e4fc4a0-370b-9101-2809-4040de58553c@gmail.com> <20180424195729.8433-1-k.marinushkin@gmail.com> <20180425061638.GA1450@kroah.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 04/25/18 08:16, Greg Kroah-Hartman wrote: > 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 at raspberrypi:/home/pi# aplay test0.wav >> Playing WAVE 'test0.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Ster >> ^CAborted by signal Interrupt... >> root at raspberrypi:/home/pi# rmmod snd_bcm2835 >> root at raspberrypi:/home/pi# modprobe snd_bcm2835 >> root at raspberrypi:/home/pi# aplay test0.wav >> Playing WAVE 'test0.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Ster >> ^CAborted by signal Interrupt... >> root at raspberrypi:/home/pi# echo scan > /sys/kernel/debug/kmemleak >> root at 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 >> Cc: Eric Anholt >> Cc: Stefan Wahren >> Cc: Greg Kroah-Hartman >> Cc: Florian Fainelli >> Cc: Ray Jui >> Cc: Scott Branden >> Cc: Andy Shevchenko >> Cc: Dan Carpenter >> Cc: bcm-kernel-feedback-list at broadcom.com >> Cc: linux-rpi-kernel at lists.infradead.org >> Cc: linux-arm-kernel at lists.infradead.org >> Cc: devel at driverdev.osuosl.org >> Cc: linux-kernel at vger.kernel.org >> --- >> .../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 :) Below is the git diff v1..v2 ~~~~ diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c index 009c972d93d6..662e05bd8f05 100644 --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c @@ -165,7 +165,7 @@ static int snd_bcm2835_create(struct snd_card *card, ???????????????????????????????????? bcm2835_devm_free_vchi_ctx, NULL, NULL); ??????? if (!chip->vchi_ctx) { ??????????????? kfree(chip); -?????????????? return err; +?????????????? return -ENODEV; ??????? } ? ??????? err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops); ~~~~ Best Regards, Kirill