diff mbox series

[v2] ALSA: core: Fix deadlock when shutdown a frozen userspace

Message ID 20221127-snd-freeze-v2-0-d8a425ea9663@chromium.org
State New
Headers
Series [v2] ALSA: core: Fix deadlock when shutdown a frozen userspace |

Commit Message

Ricardo Ribalda Nov. 28, 2022, 1:10 a.m. UTC 
  If the user space is frozen, we cannot wait for it to complete.

This fixes:

[   84.943749] Freezing user space processes ... (elapsed 0.111 seconds) done.
[  246.784446] INFO: task kexec-lite:5123 blocked for more than 122 seconds.
[  246.819035] Call Trace:
[  246.821782]  <TASK>
[  246.824186]  __schedule+0x5f9/0x1263
[  246.828231]  schedule+0x87/0xc5
[  246.831779]  snd_card_disconnect_sync+0xb5/0x127
...
[  246.889249]  snd_sof_device_shutdown+0xb4/0x150
[  246.899317]  pci_device_shutdown+0x37/0x61
[  246.903990]  device_shutdown+0x14c/0x1d6
[  246.908391]  kernel_kexec+0x45/0xb9

And

[  246.893222] INFO: task kexec-lite:4891 blocked for more than 122 seconds.
[  246.927709] Call Trace:
[  246.930461]  <TASK>
[  246.932819]  __schedule+0x5f9/0x1263
[  246.936855]  ? fsnotify_grab_connector+0x5c/0x70
[  246.942045]  schedule+0x87/0xc5
[  246.945567]  schedule_timeout+0x49/0xf3
[  246.949877]  wait_for_completion+0x86/0xe8
[  246.954463]  snd_card_free+0x68/0x89
...
[  247.001080]  platform_device_unregister+0x12/0x35

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
To: Jaroslav Kysela <perex@perex.cz>
To: Takashi Iwai <tiwai@suse.com>
Cc: alsa-devel@alsa-project.org
Cc: linux-kernel@vger.kernel.org
Cc: "Joel Fernandes (Google)" <joel@joelfernandes.org>
---
Changes in v2:
- Only use pm_freezing if CONFIG_FREEZER 
- Link to v1: https://lore.kernel.org/r/20221127-snd-freeze-v1-0-57461a366ec2@chromium.org
---
 sound/core/init.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)


---
base-commit: 4312098baf37ee17a8350725e6e0d0e8590252d4
change-id: 20221127-snd-freeze-1ee143228326

Best regards,

Comments

kernel test robot Nov. 28, 2022, 4:41 a.m. UTC | #1 
Hi Ricardo,

I love your patch! Yet something to improve:

[auto build test ERROR on 4312098baf37ee17a8350725e6e0d0e8590252d4]

url:    https://github.com/intel-lab-lkp/linux/commits/Ricardo-Ribalda/ALSA-core-Fix-deadlock-when-shutdown-a-frozen-userspace/20221128-091149
base:   4312098baf37ee17a8350725e6e0d0e8590252d4
patch link:    https://lore.kernel.org/r/20221127-snd-freeze-v2-0-d8a425ea9663%40chromium.org
patch subject: [PATCH v2] ALSA: core: Fix deadlock when shutdown a frozen userspace
config: i386-randconfig-r004-20221128
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/9d7ba98e4cc1b14b0e39c005e8216dc9fa6baddb
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Ricardo-Ribalda/ALSA-core-Fix-deadlock-when-shutdown-a-frozen-userspace/20221128-091149
        git checkout 9d7ba98e4cc1b14b0e39c005e8216dc9fa6baddb
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "pm_freezing" [sound/core/snd.ko] undefined!
diff mbox series

Patch

diff --git a/sound/core/init.c b/sound/core/init.c
index 5377f94eb211..35fb71177fea 100644
--- a/sound/core/init.c
+++ b/sound/core/init.c
@@ -9,6 +9,7 @@ 
 #include <linux/module.h>
 #include <linux/device.h>
 #include <linux/file.h>
+#include <linux/freezer.h>
 #include <linux/slab.h>
 #include <linux/time.h>
 #include <linux/ctype.h>
@@ -573,6 +574,13 @@  void snd_card_disconnect_sync(struct snd_card *card)
 		return;
 	}
 
+#ifdef CONFIG_FREEZER
+	if (pm_freezing) {
+		dev_err(card->dev, "Userspace is frozen, skipping sync\n");
+		return;
+	}
+#endif
+
 	spin_lock_irq(&card->files_lock);
 	wait_event_lock_irq(card->remove_sleep,
 			    list_empty(&card->files_list),
@@ -658,6 +666,15 @@  int snd_card_free(struct snd_card *card)
 	ret = snd_card_free_when_closed(card);
 	if (ret)
 		return ret;
+
+#ifdef CONFIG_FREEZER
+	/*
+	 * If userspace is frozen the wait from completion will never end.
+	 */
+	if (pm_freezing)
+		return 0;
+#endif
+
 	/* wait, until all devices are ready for the free operation */
 	wait_for_completion(&released);