mirror of
https://github.com/torvalds/linux.git
synced 2026-08-02 05:12:01 +02:00
Linux kernel source tree
626118b472
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
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.