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.marinush...@gmail.com> Cc: Eric Anholt <e...@anholt.net> Cc: Stefan Wahren <stefan.wah...@i2se.com> Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org> Cc: Florian Fainelli <f.faine...@gmail.com> Cc: Ray Jui <r...@broadcom.com> Cc: Scott Branden <sbran...@broadcom.com> Cc: Andy Shevchenko <andy.shevche...@gmail.com> Cc: Dan Carpenter <dan.carpen...@oracle.com> Cc: bcm-kernel-feedback-l...@broadcom.com Cc: linux-rpi-ker...@lists.infradead.org Cc: linux-arm-ker...@lists.infradead.org Cc: de...@driverdev.osuosl.org Cc: linux-kernel@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(-) diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c index 3c6f1d91d22d..389a18f9350a 100644 --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c @@ -33,7 +33,6 @@ /* ---- Include Files -------------------------------------------------------- */ -#include "interface/vchi/vchi.h" #include "vc_vchi_audioserv_defs.h" /* ---- Private Constants and Types ------------------------------------------ */ @@ -371,14 +370,46 @@ static int vc_vchi_audio_deinit(struct bcm2835_audio_instance *instance) return 0; } +int bcm2835_new_vchi_ctx(struct bcm2835_vchi_ctx *vchi_ctx) +{ + int ret; + + /* Initialize and create a VCHI connection */ + ret = vchi_initialise(&vchi_ctx->vchi_instance); + if (ret) { + LOG_ERR("%s: failed to initialise VCHI instance (ret=%d)\n", + __func__, ret); + + return -EIO; + } + + ret = vchi_connect(NULL, 0, vchi_ctx->vchi_instance); + if (ret) { + LOG_ERR("%s: failed to connect VCHI instance (ret=%d)\n", + __func__, ret); + + kfree(vchi_ctx->vchi_instance); + vchi_ctx->vchi_instance = NULL; + + return -EIO; + } + + return 0; +} + +void bcm2835_free_vchi_ctx(struct bcm2835_vchi_ctx *vchi_ctx) +{ + /* Close the VCHI connection - it will also free vchi_instance */ + WARN_ON(vchi_disconnect(vchi_ctx->vchi_instance)); + + vchi_ctx->vchi_instance = NULL; +} + static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream) { - static VCHI_INSTANCE_T vchi_instance; - static VCHI_CONNECTION_T *vchi_connection; - static int initted; struct bcm2835_audio_instance *instance = (struct bcm2835_audio_instance *)alsa_stream->instance; - int ret; + struct bcm2835_vchi_ctx *vhci_ctx = alsa_stream->chip->vchi_ctx; LOG_INFO("%s: start\n", __func__); BUG_ON(instance); @@ -390,28 +421,9 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream return 0; } - /* Initialize and create a VCHI connection */ - if (!initted) { - ret = vchi_initialise(&vchi_instance); - if (ret) { - LOG_ERR("%s: failed to initialise VCHI instance (ret=%d)\n", - __func__, ret); - - return -EIO; - } - ret = vchi_connect(NULL, 0, vchi_instance); - if (ret) { - LOG_ERR("%s: failed to connect VCHI instance (ret=%d)\n", - __func__, ret); - - kfree(vchi_instance); - return -EIO; - } - initted = 1; - } - /* Initialize an instance of the audio service */ - instance = vc_vchi_audio_init(vchi_instance, &vchi_connection, 1); + instance = vc_vchi_audio_init(vhci_ctx->vchi_instance, + &vhci_ctx->vchi_connection, 1); if (IS_ERR(instance)) { LOG_ERR("%s: failed to initialize audio service\n", __func__); diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c index 9030d71a3d0b..662e05bd8f05 100644 --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c @@ -65,6 +65,36 @@ static int snd_devm_add_child(struct device *dev, struct device *child) return 0; } +static void bcm2835_devm_free_vchi_ctx(struct device *dev, void *res) +{ + struct bcm2835_vchi_ctx *vchi_ctx = res; + + bcm2835_free_vchi_ctx(vchi_ctx); +} + +static int bcm2835_devm_add_vchi_ctx(struct device *dev) +{ + struct bcm2835_vchi_ctx *vchi_ctx; + int ret; + + vchi_ctx = devres_alloc(bcm2835_devm_free_vchi_ctx, sizeof(*vchi_ctx), + GFP_KERNEL); + if (!vchi_ctx) + return -ENOMEM; + + memset(vchi_ctx, 0, sizeof(*vchi_ctx)); + + ret = bcm2835_new_vchi_ctx(vchi_ctx); + if (ret) { + devres_free(vchi_ctx); + return ret; + } + + devres_add(dev, vchi_ctx); + + return 0; +} + static void snd_bcm2835_release(struct device *dev) { struct bcm2835_chip *chip = dev_get_drvdata(dev); @@ -106,8 +136,6 @@ static int snd_bcm2835_dev_free(struct snd_device *device) struct bcm2835_chip *chip = device->device_data; struct snd_card *card = chip->card; - /* TODO: free pcm, ctl */ - snd_device_free(card, chip); return 0; @@ -133,6 +161,13 @@ static int snd_bcm2835_create(struct snd_card *card, chip->card = card; + chip->vchi_ctx = devres_find(card->dev->parent, + bcm2835_devm_free_vchi_ctx, NULL, NULL); + if (!chip->vchi_ctx) { + kfree(chip); + return -ENODEV; + } + err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops); if (err) { kfree(chip); @@ -403,6 +438,10 @@ static int snd_bcm2835_alsa_probe_dt(struct platform_device *pdev) numchans); } + err = bcm2835_devm_add_vchi_ctx(dev); + if (err) + return err; + err = snd_add_child_devices(dev, numchans); if (err) return err; diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.h b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.h index f1e43e45fd67..1c82c2ee47dc 100644 --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.h +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.h @@ -26,6 +26,8 @@ #include <sound/pcm-indirect.h> #include <linux/workqueue.h> +#include "interface/vchi/vchi.h" + /* * #define AUDIO_DEBUG_ENABLE * #define AUDIO_VERBOSE_DEBUG_ENABLE @@ -97,6 +99,11 @@ enum snd_bcm2835_ctrl { PCM_PLAYBACK_DEVICE, }; +struct bcm2835_vchi_ctx { + VCHI_INSTANCE_T vchi_instance; + VCHI_CONNECTION_T *vchi_connection; +}; + /* definition of the chip-specific record */ struct bcm2835_chip { struct snd_card *card; @@ -115,6 +122,8 @@ struct bcm2835_chip { unsigned int opened; unsigned int spdif_status; struct mutex audio_mutex; + + struct bcm2835_vchi_ctx *vchi_ctx; }; struct bcm2835_alsa_stream { @@ -153,6 +162,9 @@ int snd_bcm2835_new_simple_pcm(struct bcm2835_chip *chip, int snd_bcm2835_new_hdmi_ctl(struct bcm2835_chip *chip); int snd_bcm2835_new_headphones_ctl(struct bcm2835_chip *chip); +int bcm2835_new_vchi_ctx(struct bcm2835_vchi_ctx *vchi_ctx); +void bcm2835_free_vchi_ctx(struct bcm2835_vchi_ctx *vchi_ctx); + int bcm2835_audio_open(struct bcm2835_alsa_stream *alsa_stream); int bcm2835_audio_close(struct bcm2835_alsa_stream *alsa_stream); int bcm2835_audio_set_params(struct bcm2835_alsa_stream *alsa_stream, -- 2.13.6