lkml.org 
[lkml]   [2020]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v2 3/3] libnvdimm/security: ensure sysfs poll thread woke up and fetch updated attr
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 <dave.jiang@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Fixes: 7d988097c546 ("acpi/nfit, libnvdimm/security: Add security DSM overwrite support")
> Signed-off-by: Jane Chu <jane.chu@oracle.com>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>

Reviewed-by: Ira Weiny <ira.weiny@intel.com>

> ---
> 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
>

\
 
 \ /
  Last update: 2020-08-06 21:26    [W:0.057 / U:1.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site