From e7bd1d8efc78044d4e8d4a1d74f627b44bf45203 Mon Sep 17 00:00:00 2001 From: Jane Chu Date: Mon, 3 Aug 2020 16:41:39 -0600 Subject: libnvdimm/security: ensure sysfs poll thread woke up and fetch updated attr [ Upstream commit 7f674025d9f7321dea11b802cc0ab3f09cbe51c5 ] 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. Link: https://lore.kernel.org/r/1596494499-9852-3-git-send-email-jane.chu@oracle.com Fixes: 7d988097c546 ("acpi/nfit, libnvdimm/security: Add security DSM overwrite support") Cc: Dave Jiang Cc: Dan Williams Reviewed-by: Dave Jiang Signed-off-by: Jane Chu Signed-off-by: Vishal Verma Signed-off-by: Sasha Levin --- 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 acfd211c01b9..35d265014e1e 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) -- cgit v1.2.3