On Mon, Aug 03, 2020 at 04:41:39PM -0600, Jane Chu wrote:
> commit 7d988097c546 ("acpi/nfit, libnvdimm/security: Add security DSM
> overwrite support")
> adds a sysfs_notify_dirent() to wake up userspace poll thread when the
> "overwrite"
> operation has completed. But the notification is issued before the internal
> dimm security state and flags have been updated, so the userspace poll thread
> wakes up and fetches the not-yet-updated attr and falls back to sleep,
> forever.
> But if user from another terminal issue "ndctl wait-overwrite nmemX" again,
> the command returns instantly.
>
> Cc: Dave Jiang <[email protected]>
> Cc: Dan Williams <[email protected]>
> Fixes: 7d988097c546 ("acpi/nfit, libnvdimm/security: Add security DSM
> overwrite support")
> Signed-off-by: Jane Chu <[email protected]>
> Reviewed-by: Dave Jiang <[email protected]>
Reviewed-by: Ira Weiny <[email protected]>
> ---
> drivers/nvdimm/security.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/nvdimm/security.c b/drivers/nvdimm/security.c
> index 8f3971c..4b80150 100644
> --- a/drivers/nvdimm/security.c
> +++ b/drivers/nvdimm/security.c
> @@ -450,14 +450,19 @@ void __nvdimm_security_overwrite_query(struct nvdimm
> *nvdimm)
> else
> dev_dbg(&nvdimm->dev, "overwrite completed\n");
>
> - if (nvdimm->sec.overwrite_state)
> - sysfs_notify_dirent(nvdimm->sec.overwrite_state);
> + /*
> + * Mark the overwrite work done and update dimm security flags,
> + * then send a sysfs event notification to wake up userspace
> + * poll threads to picked up the changed state.
> + */
> nvdimm->sec.overwrite_tmo = 0;
> clear_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags);
> clear_bit(NDD_WORK_PENDING, &nvdimm->flags);
> - put_device(&nvdimm->dev);
> nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
> nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm, NVDIMM_MASTER);
> + if (nvdimm->sec.overwrite_state)
> + sysfs_notify_dirent(nvdimm->sec.overwrite_state);
> + put_device(&nvdimm->dev);
> }
>
> void nvdimm_security_overwrite_query(struct work_struct *work)
> --
> 1.8.3.1
>
