On 12/2/22 02:58, Mason Zhang wrote:
From: Mason Zhang <Mason.Zhang@xxxxxxxxxxxx>
In ufs error handler flow, host will send device management cmd(NOP OUT)
to device for recovery link. If cmd response timeout, and clear doorbell
fail, ufshcd_wait_for_dev_cmd will do nothing and return,
hba->dev_cmd.complete struct not set to null.
In this time, if cmd has been responsed by device, then it will
call complete() in __ufshcd_transfer_req_compl, because of complete
struct is alloced in stack, then the KE will occur.
Fix the following crash:
ipanic_die+0x24/0x38 [mrdump]
die+0x344/0x748
arm64_notify_die+0x44/0x104
do_debug_exception+0x104/0x1e0
el1_dbg+0x38/0x54
el1_sync_handler+0x40/0x88
el1_sync+0x8c/0x140
queued_spin_lock_slowpath+0x2e4/0x3c0
__ufshcd_transfer_req_compl+0x3b0/0x1164
ufshcd_trc_handler+0x15c/0x308
ufshcd_host_reset_and_restore+0x54/0x260
ufshcd_reset_and_restore+0x28c/0x57c
ufshcd_err_handler+0xeb8/0x1b6c
process_one_work+0x288/0x964
worker_thread+0x4bc/0xc7c
kthread+0x15c/0x264
ret_from_fork+0x10/0x30
Change-Id: Id17da259894294b61bef41cf7dfb94506e7e0310
Please verify patches with checkpatch before posting these upstream. Checkpatch
will tell you that Change-Id tags must be removed before posting a patch upstream.
Signed-off-by: Mason Zhang <Mason.Zhang@xxxxxxxxxxxx>
---
drivers/ufs/core/ufshcd.c | 46 ++++++++++++++++++---------------------
1 file changed, 21 insertions(+), 25 deletions(-)
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index b1f59a5fe632..2b4934a562a6 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2979,35 +2979,31 @@ static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
err = -ETIMEDOUT;
dev_dbg(hba->dev, "%s: dev_cmd request timedout, tag %d\n",
__func__, lrbp->task_tag);
- if (ufshcd_clear_cmds(hba, 1U << lrbp->task_tag) == 0) {
+ if (ufshcd_clear_cmds(hba, 1U << lrbp->task_tag) == 0)
/* successfully cleared the command, retry if needed */
err = -EAGAIN;
+ /*
+ * Since clearing the command succeeded we also need to
+ * clear the task tag bit from the outstanding_reqs
+ * variable.
+ */
+ spin_lock_irqsave(&hba->outstanding_lock, flags);
+ pending = test_bit(lrbp->task_tag,
+ &hba->outstanding_reqs);
+ if (pending) {
+ hba->dev_cmd.complete = NULL;
+ __clear_bit(lrbp->task_tag,
+ &hba->outstanding_reqs);
+ }
+ spin_unlock_irqrestore(&hba->outstanding_lock, flags);
I don't think it is safe to clear the corresponding bit from outstanding_reqs
if ufshcd_clear_cmds() returns a value != 0.
Instead of making all these changes, would the following patch be sufficient?
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index bb4cbfe7fd57..d5deec621d2a 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -3008,6 +3008,9 @@ static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
} else {
dev_err(hba->dev, "%s: failed to clear tag %d\n",
__func__, lrbp->task_tag);
+ spin_lock_irqsave(&hba->outstanding_lock, flags);
+ hba->dev_cmd.complete = NULL;
+ spin_unlock_irqrestore(&hba->outstanding_lock, flags);
}
}
Thanks,
Bart.
