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authorLu Jialin <lujialin4@huawei.com>2023-09-04 13:33:41 +0000
committerHerbert Xu <herbert@gondor.apana.org.au>2023-09-15 18:29:45 +0800
commit8f4f68e788c3a7a696546291258bfa5fdb215523 (patch)
treef0aeb909c8de0fbc09b3e2b23d86b0cf3211b096
parent6b36dafedd53276a8fb7d7a12ee549560e48b8ee (diff)
crypto: pcrypt - Fix hungtask for PADATA_RESET
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 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, we replace the return err -EBUSY with -EAGAIN, which means parallel_data is changing, and the caller should call it again. v3: remove retry and just change the return err. v2: introduce padata_try_do_parallel() in pcrypt_aead_encrypt and pcrypt_aead_decrypt to solve the hungtask. Signed-off-by: Lu Jialin <lujialin4@huawei.com> Signed-off-by: Guo Zihua <guozihua@huawei.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--crypto/pcrypt.c4
-rw-r--r--kernel/padata.c2
2 files changed, 5 insertions, 1 deletions
diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c
index 8c1d0ca41213..d0d954fe9d54 100644
--- a/crypto/pcrypt.c
+++ b/crypto/pcrypt.c
@@ -117,6 +117,8 @@ static int pcrypt_aead_encrypt(struct aead_request *req)
err = padata_do_parallel(ictx->psenc, padata, &ctx->cb_cpu);
if (!err)
return -EINPROGRESS;
+ if (err == -EBUSY)
+ return -EAGAIN;
return err;
}
@@ -164,6 +166,8 @@ static int pcrypt_aead_decrypt(struct aead_request *req)
err = padata_do_parallel(ictx->psdec, padata, &ctx->cb_cpu);
if (!err)
return -EINPROGRESS;
+ if (err == -EBUSY)
+ return -EAGAIN;
return err;
}
diff --git a/kernel/padata.c b/kernel/padata.c
index 222d60195de6..81c8183f3176 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -202,7 +202,7 @@ int padata_do_parallel(struct padata_shell *ps,
*cb_cpu = cpu;
}
- err = -EBUSY;
+ err = -EBUSY;
if ((pinst->flags & PADATA_RESET))
goto out;