Messages in this thread | | | Subject | Re: [PATCH v2] remoteproc: sysfs/debugfs: fix race while updating recovery flag | From | Satya Durga Srinivasu Prabhala <> | Date | Mon, 6 Feb 2023 18:12:02 -0800 |
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On 2/1/23 4:05 AM, Mukesh Ojha wrote: > > > On 2/1/2023 11:16 AM, Satya Durga Srinivasu Prabhala wrote: >> When multiple clients try to update the recovery flag, it is >> possible that, race condition would lead to undesired results >> as updates to recovery flag isn't protected by any mechanism >> today. To avoid such issues, take remoteproc mutex lock before >> updating recovery flag and release the lock once done. >> >> Signed-off-by: Satya Durga Srinivasu Prabhala <quic_satyap@quicinc.com> > > LGTM. > > Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Thanks Mukesh.
Hi Bjorn,
Can you help cross check?
Best, Satya
> > -Mukesh >> --- >> v1 -> v2: >> - addressed comments from Mukesh Ojha >> 1. take & release lock only while updating recovery flag >> 2. update debugfs >> >> drivers/remoteproc/remoteproc_debugfs.c | 4 ++++ >> drivers/remoteproc/remoteproc_sysfs.c | 4 ++++ >> 2 files changed, 8 insertions(+) >> >> diff --git a/drivers/remoteproc/remoteproc_debugfs.c >> b/drivers/remoteproc/remoteproc_debugfs.c >> index b86c1d09c70c..2c44d375024e 100644 >> --- a/drivers/remoteproc/remoteproc_debugfs.c >> +++ b/drivers/remoteproc/remoteproc_debugfs.c >> @@ -226,10 +226,14 @@ rproc_recovery_write(struct file *filp, const >> char __user *user_buf, >> >> if (!strncmp(buf, "enabled", count)) { >> /* change the flag and begin the recovery process if needed */ >> + mutex_lock(&rproc->lock); >> rproc->recovery_disabled = false; >> + mutex_unlock(&rproc->lock); >> rproc_trigger_recovery(rproc); >> } else if (!strncmp(buf, "disabled", count)) { >> + mutex_lock(&rproc->lock); >> rproc->recovery_disabled = true; >> + mutex_unlock(&rproc->lock); >> } else if (!strncmp(buf, "recover", count)) { >> /* begin the recovery process without changing the flag */ >> rproc_trigger_recovery(rproc); >> diff --git a/drivers/remoteproc/remoteproc_sysfs.c >> b/drivers/remoteproc/remoteproc_sysfs.c >> index 8c7ea8922638..628e0de9a132 100644 >> --- a/drivers/remoteproc/remoteproc_sysfs.c >> +++ b/drivers/remoteproc/remoteproc_sysfs.c >> @@ -50,10 +50,14 @@ static ssize_t recovery_store(struct device *dev, >> >> if (sysfs_streq(buf, "enabled")) { >> /* change the flag and begin the recovery process if needed */ >> + mutex_lock(&rproc->lock); >> rproc->recovery_disabled = false; >> + mutex_unlock(&rproc->lock); >> rproc_trigger_recovery(rproc); >> } else if (sysfs_streq(buf, "disabled")) { >> + mutex_lock(&rproc->lock); >> rproc->recovery_disabled = true; >> + mutex_unlock(&rproc->lock); >> } else if (sysfs_streq(buf, "recover")) { >> /* begin the recovery process without changing the flag */ >> rproc_trigger_recovery(rproc);
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