Thanks for your suggestions. I will update my patch in v2 On 2023/8/18 14:02, Herbert Xu wrote:
Lu Jialin <lujialin4@xxxxxxxxxx> wrote:We found a hungtask bug in test_aead_vec_cfg as follows: INFO: task cryptomgr_test:391009 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Call trace: __switch_to+0x98/0xe0 __schedule+0x6c4/0xf40 schedule+0xd8/0x1b4 schedule_timeout+0x474/0x560 wait_for_common+0x368/0x4e0 wait_for_completion+0x20/0x30 test_aead_vec_cfg+0xab4/0xd50 test_aead+0x144/0x1f0 alg_test_aead+0xd8/0x1e0 alg_test+0x634/0x890 cryptomgr_test+0x40/0x70 kthread+0x1e0/0x220 ret_from_fork+0x10/0x18 Kernel panic - not syncing: hung_task: blocked tasks For padata_do_parallel, when the return err is 0 or -EBUSY, it will call wait_for_completion(&wait->completion) in test_aead_vec_cfg. In normal case, aead_request_complete() will be called in pcrypt_aead_serial and the return err is 0 for padata_do_parallel. But, when pinst->flags is PADATA_RESET, the return err is -EBUSY for padata_do_parallel, and it won't call aead_request_complete(). Therefore, test_aead_vec_cfg will hung at wait_for_completion(&wait->completion), which will cause hungtask. The problem comes as following: (padata_do_parallel) | rcu_read_lock_bh(); | err = -EINVAL; | (padata_replace) | pinst->flags |= PADATA_RESET; err = -EBUSY | if (pinst->flags & PADATA_RESET) | rcu_read_unlock_bh() | return err | In order to resolve the problem, change the return err to -EINVAL when pinst->flags is set PADATA_RESET. Signed-off-by: Lu Jialin <lujialin4@xxxxxxxxxx> --- kernel/padata.c | 1 - 1 file changed, 1 deletion(-)Thanks for the patch. So the issue here is that the Crypto API uses EBUSY for a specific purpose but padata uses it too and they're getting confused with each other. I think what we should do is get pcrypt to check the error value from padata_do_parallel, and if it's EBUSY then change it to something else. Thanks,
