4.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kirill Marinushkin k.marinushkin@gmail.com
[ Upstream commit 626118b472d2eb45f83a0276a18d3e6a01c69f6a ]
In the current implementation, `rmmod snd_bcm2835` does not release resources properly. It causes an oops when trying to list sound devices.
This commit fixes it.
The details WRT allocation / free are described below.
Device structure WRT allocation:
pdev \childdev[] \card \chip \pcm \ctl
Allocation / register sequence:
* childdev: devm_kzalloc - freed during driver detach * childdev: device_initialize - freed during device_unregister * pdev: devres_alloc - freed during driver detach * childdev: device_add - removed during device_unregister * pdev, childdev: devres_add - freed during driver detach * card: snd_card_new - freed during snd_card_free * chip: kzalloc - freed during kfree * card, chip: snd_device_new - freed during snd_device_free * chip: new_pcm - TODO: free pcm * chip: new_ctl - TODO: free ctl * card: snd_card_register - unregistered during snd_card_free
Free / unregister sequence:
* card: snd_card_free * card, chip: snd_device_free * childdev: device_unregister * chip: kfree
Steps to reproduce the issue before this commit:
~~~~ $ rmmod snd_bcm2835 $ aplay -L [ 138.648130] Unable to handle kernel paging request at virtual address 7f1343c0 [ 138.660415] pgd = ad8f0000 [ 138.665567] [7f1343c0] *pgd=3864c811, *pte=00000000, *ppte=00000000 [ 138.674887] Internal error: Oops: 7 [#1] SMP ARM [ 138.683571] Modules linked in: sha256_generic cfg80211 rfkill snd_pcm snd_timer snd fixed uio_pdrv_genirq uio ip_tables x_tables ipv6 [last unloaded: snd_bcm2835 ] [ 138.706594] CPU: 3 PID: 463 Comm: aplay Tainted: G WC 4.15.0-rc1-v 7+ #6 [ 138.719833] Hardware name: BCM2835 [ 138.726016] task: b877ac00 task.stack: aebec000 [ 138.733408] PC is at try_module_get+0x38/0x24c [ 138.740813] LR is at snd_ctl_open+0x58/0x194 [snd] [ 138.748485] pc : [<801c4d5c>] lr : [<7f0e6b2c>] psr: 20000013 [ 138.757709] sp : aebedd60 ip : aebedd88 fp : aebedd84 [ 138.765884] r10: 00000000 r9 : 00000004 r8 : 7f0ed440 [ 138.774040] r7 : b7e469b0 r6 : 7f0e6b2c r5 : afd91900 r4 : 7f1343c0 [ 138.783571] r3 : aebec000 r2 : 00000001 r1 : b877ac00 r0 : 7f1343c0 [ 138.793084] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 138.803300] Control: 10c5387d Table: 2d8f006a DAC: 00000055 [ 138.812064] Process aplay (pid: 463, stack limit = 0xaebec210) [ 138.820868] Stack: (0xaebedd60 to 0xaebee000) [ 138.828207] dd60: 00000000 b848d000 afd91900 00000000 b7e469b0 7f0ed440 aebedda4 aebedd88 [ 138.842371] dd80: 7f0e6b2c 801c4d30 afd91900 7f0ea4dc 00000000 b7e469b0 aebeddcc aebedda8 [ 138.856611] dda0: 7f0e250c 7f0e6ae0 7f0e2464 b8478ec0 b7e469b0 afd91900 7f0ea388 00000000 [ 138.870864] ddc0: aebeddf4 aebeddd0 802ce590 7f0e2470 8090ab64 afd91900 afd91900 b7e469b0 [ 138.885301] dde0: afd91908 802ce4e4 aebede1c aebeddf8 802c57b4 802ce4f0 afd91900 aebedea8 [ 138.900110] de00: b7fa4c00 00000000 00000000 00000004 aebede3c aebede20 802c6ba8 802c56b4 [ 138.915260] de20: aebedea8 00000000 aebedf5c 00000000 aebedea4 aebede40 802d9a68 802c6b58 [ 138.930661] de40: b874ddd0 00000000 00000000 00000001 00000041 00000000 afd91900 aebede70 [ 138.946402] de60: 00000000 00000000 00000002 b7e469b0 b8a87610 b8d6ab80 801852f8 00080000 [ 138.962314] de80: aebedf5c aebedea8 00000001 80108464 aebec000 00000000 aebedf4c aebedea8 [ 138.978414] dea0: 802dacd4 802d970c b8a87610 b8d6ab80 a7982bc6 00000009 af363019 b9231480 [ 138.994617] dec0: 00000000 b8c038a0 b7e469b0 00000101 00000002 00000238 00000000 00000000 [ 139.010823] dee0: 00000000 aebedee8 00080000 0000000f aebedf3c aebedf00 802ed7e4 80843f94 [ 139.027025] df00: 00000003 00080000 b9231490 b9231480 00000000 00080000 af363000 00000000 [ 139.043229] df20: 00000005 00000002 ffffff9c 00000000 00080000 ffffff9c af363000 00000003 [ 139.059430] df40: aebedf94 aebedf50 802c6f70 802dac70 aebec000 00000000 00000001 00000000 [ 139.075629] df60: 00020000 00000004 00000100 00000001 7ebe577c 0002e038 00000000 00000005 [ 139.091828] df80: 80108464 aebec000 aebedfa4 aebedf98 802c7060 802c6e6c 00000000 aebedfa8 [ 139.108025] dfa0: 801082c0 802c7040 7ebe577c 0002e038 7ebe577c 00080000 00000b98 e81c8400 [ 139.124222] dfc0: 7ebe577c 0002e038 00000000 00000005 7ebe57e4 00a20af8 7ebe57f0 76f87394 [ 139.140419] dfe0: 00000000 7ebe55c4 76ec88e8 76df1d9c 60000010 7ebe577c 00000000 00000000 [ 139.156715] [<801c4d5c>] (try_module_get) from [<7f0e6b2c>] (snd_ctl_open+0x58/0x194 [snd]) [ 139.173222] [<7f0e6b2c>] (snd_ctl_open [snd]) from [<7f0e250c>] (snd_open+0xa8/0x14c [snd]) [ 139.189683] [<7f0e250c>] (snd_open [snd]) from [<802ce590>] (chrdev_open+0xac/0x188) [ 139.205465] [<802ce590>] (chrdev_open) from [<802c57b4>] (do_dentry_open+0x10c/0x314) [ 139.221347] [<802c57b4>] (do_dentry_open) from [<802c6ba8>] (vfs_open+0x5c/0x88) [ 139.236788] [<802c6ba8>] (vfs_open) from [<802d9a68>] (path_openat+0x368/0x944) [ 139.248270] [<802d9a68>] (path_openat) from [<802dacd4>] (do_filp_open+0x70/0xc4) [ 139.263731] [<802dacd4>] (do_filp_open) from [<802c6f70>] (do_sys_open+0x110/0x1d4) [ 139.279378] [<802c6f70>] (do_sys_open) from [<802c7060>] (SyS_open+0x2c/0x30) [ 139.290647] [<802c7060>] (SyS_open) from [<801082c0>] (ret_fast_syscall+0x0/0x28) [ 139.306021] Code: e3c3303f e5932004 e2822001 e5832004 (e5943000) [ 139.316265] ---[ end trace 7f3f7f6193b663ed ]--- [ 139.324956] note: aplay[463] exited with preempt_count 1 ~~~~
Signed-off-by: Kirill Marinushkin k.marinushkin@gmail.com Cc: Eric Anholt eric@anholt.net Cc: Stefan Wahren stefan.wahren@i2se.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Florian Fainelli f.fainelli@gmail.com Cc: Ray Jui rjui@broadcom.com Cc: Scott Branden sbranden@broadcom.com Cc: bcm-kernel-feedback-list@broadcom.com Cc: Michael Zoran mzoran@crowfest.net Cc: Andy Shevchenko andy.shevchenko@gmail.com Cc: linux-rpi-kernel@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Cc: devel@driverdev.osuosl.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/vc04_services/bcm2835-audio/bcm2835.c | 54 ++++++++---------- 1 file changed, 25 insertions(+), 29 deletions(-)
--- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835.c @@ -25,6 +25,10 @@ MODULE_PARM_DESC(enable_compat_alsa, static void snd_devm_unregister_child(struct device *dev, void *res) { struct device *childdev = *(struct device **)res; + struct bcm2835_chip *chip = dev_get_drvdata(childdev); + struct snd_card *card = chip->card; + + snd_card_free(card);
device_unregister(childdev); } @@ -50,6 +54,13 @@ static int snd_devm_add_child(struct dev return 0; }
+static void snd_bcm2835_release(struct device *dev) +{ + struct bcm2835_chip *chip = dev_get_drvdata(dev); + + kfree(chip); +} + static struct device * snd_create_device(struct device *parent, struct device_driver *driver, @@ -65,6 +76,7 @@ snd_create_device(struct device *parent, device_initialize(device); device->parent = parent; device->driver = driver; + device->release = snd_bcm2835_release;
dev_set_name(device, "%s", name);
@@ -75,18 +87,19 @@ snd_create_device(struct device *parent, return device; }
-static int snd_bcm2835_free(struct bcm2835_chip *chip) -{ - kfree(chip); - return 0; -} - /* component-destructor * (see "Management of Cards and Components") */ static int snd_bcm2835_dev_free(struct snd_device *device) { - return snd_bcm2835_free(device->device_data); + struct bcm2835_chip *chip = device->device_data; + struct snd_card *card = chip->card; + + /* TODO: free pcm, ctl */ + + snd_device_free(card, chip); + + return 0; }
/* chip-specific constructor @@ -111,7 +124,7 @@ static int snd_bcm2835_create(struct snd
err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops); if (err) { - snd_bcm2835_free(chip); + kfree(chip); return err; }
@@ -119,31 +132,14 @@ static int snd_bcm2835_create(struct snd return 0; }
-static void snd_devm_card_free(struct device *dev, void *res) +static struct snd_card *snd_bcm2835_card_new(struct device *dev) { - struct snd_card *snd_card = *(struct snd_card **)res; - - snd_card_free(snd_card); -} - -static struct snd_card *snd_devm_card_new(struct device *dev) -{ - struct snd_card **dr; struct snd_card *card; int ret;
- dr = devres_alloc(snd_devm_card_free, sizeof(*dr), GFP_KERNEL); - if (!dr) - return ERR_PTR(-ENOMEM); - ret = snd_card_new(dev, -1, NULL, THIS_MODULE, 0, &card); - if (ret) { - devres_free(dr); + if (ret) return ERR_PTR(ret); - } - - *dr = card; - devres_add(dev, dr);
return card; } @@ -260,7 +256,7 @@ static int snd_add_child_device(struct d return PTR_ERR(child); }
- card = snd_devm_card_new(child); + card = snd_bcm2835_card_new(child); if (IS_ERR(card)) { dev_err(child, "Failed to create card"); return PTR_ERR(card); @@ -302,7 +298,7 @@ static int snd_add_child_device(struct d return err; }
- dev_set_drvdata(child, card); + dev_set_drvdata(child, chip); dev_info(child, "card created with %d channels\n", numchans);
return 0;