[v2,2/3] libnvdimm/security: Tighten scope of nvdimm->busy vs security operations
diff mbox series

Message ID 156686729996.184120.3458026302402493937.stgit@dwillia2-desk3.amr.corp.intel.com
State Mainlined
Commit bc4f2199ca3107809df96cf72f618b9559b00a21
Headers show
Series
  • libnvdimm/security: Enumerate the frozen state and other cleanups
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Commit Message

Dan Williams Aug. 27, 2019, 12:55 a.m. UTC
An attempt to freeze DIMMs currently runs afoul of default blocking of
all security operations in the entry to the 'store' routine for the
'security' sysfs attribute.

The blanket blocking of all security operations while the DIMM is in
active use in a region is too restrictive. The only security operations
that need to be aware of the ->busy state are those that mutate the
state of data, i.e. erase and overwrite.

Refactor the ->busy checks to be applied at the entry common entry point
in __security_store() rather than each of the helper routines to enable
freeze to be run regardless of busy state.

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/nvdimm/dimm_devs.c |   33 ++++++++++++++++-----------------
 drivers/nvdimm/security.c  |   10 ----------
 2 files changed, 16 insertions(+), 27 deletions(-)

Comments

Jeff Moyer Aug. 28, 2019, 5:57 p.m. UTC | #1
Dan Williams <dan.j.williams@intel.com> writes:

> An attempt to freeze DIMMs currently runs afoul of default blocking of
> all security operations in the entry to the 'store' routine for the
> 'security' sysfs attribute.
>
> The blanket blocking of all security operations while the DIMM is in
> active use in a region is too restrictive. The only security operations
> that need to be aware of the ->busy state are those that mutate the
> state of data, i.e. erase and overwrite.
>
> Refactor the ->busy checks to be applied at the entry common entry point
> in __security_store() rather than each of the helper routines to enable
> freeze to be run regardless of busy state.
>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>

> ---
>  drivers/nvdimm/dimm_devs.c |   33 ++++++++++++++++-----------------
>  drivers/nvdimm/security.c  |   10 ----------
>  2 files changed, 16 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
> index 53330625fe07..d837cb9be83d 100644
> --- a/drivers/nvdimm/dimm_devs.c
> +++ b/drivers/nvdimm/dimm_devs.c
> @@ -424,9 +424,6 @@ static ssize_t __security_store(struct device *dev, const char *buf, size_t len)
>  	unsigned int key, newkey;
>  	int i;
>  
> -	if (atomic_read(&nvdimm->busy))
> -		return -EBUSY;
> -
>  	rc = sscanf(buf, "%"__stringify(SEC_CMD_SIZE)"s"
>  			" %"__stringify(KEY_ID_SIZE)"s"
>  			" %"__stringify(KEY_ID_SIZE)"s",
> @@ -451,23 +448,25 @@ static ssize_t __security_store(struct device *dev, const char *buf, size_t len)
>  	} else if (i == OP_DISABLE) {
>  		dev_dbg(dev, "disable %u\n", key);
>  		rc = nvdimm_security_disable(nvdimm, key);
> -	} else if (i == OP_UPDATE) {
> -		dev_dbg(dev, "update %u %u\n", key, newkey);
> -		rc = nvdimm_security_update(nvdimm, key, newkey, NVDIMM_USER);
> -	} else if (i == OP_ERASE) {
> -		dev_dbg(dev, "erase %u\n", key);
> -		rc = nvdimm_security_erase(nvdimm, key, NVDIMM_USER);
> +	} else if (i == OP_UPDATE || i == OP_MASTER_UPDATE) {
> +		dev_dbg(dev, "%s %u %u\n", ops[i].name, key, newkey);
> +		rc = nvdimm_security_update(nvdimm, key, newkey, i == OP_UPDATE
> +				? NVDIMM_USER : NVDIMM_MASTER);
> +	} else if (i == OP_ERASE || i == OP_MASTER_ERASE) {
> +		dev_dbg(dev, "%s %u\n", ops[i].name, key);
> +		if (atomic_read(&nvdimm->busy)) {
> +			dev_dbg(dev, "Unable to secure erase while DIMM active.\n");
> +			return -EBUSY;
> +		}
> +		rc = nvdimm_security_erase(nvdimm, key, i == OP_ERASE
> +				? NVDIMM_USER : NVDIMM_MASTER);
>  	} else if (i == OP_OVERWRITE) {
>  		dev_dbg(dev, "overwrite %u\n", key);
> +		if (atomic_read(&nvdimm->busy)) {
> +			dev_dbg(dev, "Unable to overwrite while DIMM active.\n");
> +			return -EBUSY;
> +		}
>  		rc = nvdimm_security_overwrite(nvdimm, key);
> -	} else if (i == OP_MASTER_UPDATE) {
> -		dev_dbg(dev, "master_update %u %u\n", key, newkey);
> -		rc = nvdimm_security_update(nvdimm, key, newkey,
> -				NVDIMM_MASTER);
> -	} else if (i == OP_MASTER_ERASE) {
> -		dev_dbg(dev, "master_erase %u\n", key);
> -		rc = nvdimm_security_erase(nvdimm, key,
> -				NVDIMM_MASTER);
>  	} else
>  		return -EINVAL;
>  
> diff --git a/drivers/nvdimm/security.c b/drivers/nvdimm/security.c
> index 5862d0eee9db..2166e627383a 100644
> --- a/drivers/nvdimm/security.c
> +++ b/drivers/nvdimm/security.c
> @@ -334,11 +334,6 @@ int nvdimm_security_erase(struct nvdimm *nvdimm, unsigned int keyid,
>  			|| !nvdimm->sec.flags)
>  		return -EOPNOTSUPP;
>  
> -	if (atomic_read(&nvdimm->busy)) {
> -		dev_dbg(dev, "Unable to secure erase while DIMM active.\n");
> -		return -EBUSY;
> -	}
> -
>  	rc = check_security_state(nvdimm);
>  	if (rc)
>  		return rc;
> @@ -380,11 +375,6 @@ int nvdimm_security_overwrite(struct nvdimm *nvdimm, unsigned int keyid)
>  			|| !nvdimm->sec.flags)
>  		return -EOPNOTSUPP;
>  
> -	if (atomic_read(&nvdimm->busy)) {
> -		dev_dbg(dev, "Unable to overwrite while DIMM active.\n");
> -		return -EBUSY;
> -	}
> -
>  	if (dev->driver == NULL) {
>  		dev_dbg(dev, "Unable to overwrite while DIMM active.\n");
>  		return -EINVAL;
>
> _______________________________________________
> Linux-nvdimm mailing list
> Linux-nvdimm@lists.01.org
> https://lists.01.org/mailman/listinfo/linux-nvdimm

Patch
diff mbox series

diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index 53330625fe07..d837cb9be83d 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -424,9 +424,6 @@  static ssize_t __security_store(struct device *dev, const char *buf, size_t len)
 	unsigned int key, newkey;
 	int i;
 
-	if (atomic_read(&nvdimm->busy))
-		return -EBUSY;
-
 	rc = sscanf(buf, "%"__stringify(SEC_CMD_SIZE)"s"
 			" %"__stringify(KEY_ID_SIZE)"s"
 			" %"__stringify(KEY_ID_SIZE)"s",
@@ -451,23 +448,25 @@  static ssize_t __security_store(struct device *dev, const char *buf, size_t len)
 	} else if (i == OP_DISABLE) {
 		dev_dbg(dev, "disable %u\n", key);
 		rc = nvdimm_security_disable(nvdimm, key);
-	} else if (i == OP_UPDATE) {
-		dev_dbg(dev, "update %u %u\n", key, newkey);
-		rc = nvdimm_security_update(nvdimm, key, newkey, NVDIMM_USER);
-	} else if (i == OP_ERASE) {
-		dev_dbg(dev, "erase %u\n", key);
-		rc = nvdimm_security_erase(nvdimm, key, NVDIMM_USER);
+	} else if (i == OP_UPDATE || i == OP_MASTER_UPDATE) {
+		dev_dbg(dev, "%s %u %u\n", ops[i].name, key, newkey);
+		rc = nvdimm_security_update(nvdimm, key, newkey, i == OP_UPDATE
+				? NVDIMM_USER : NVDIMM_MASTER);
+	} else if (i == OP_ERASE || i == OP_MASTER_ERASE) {
+		dev_dbg(dev, "%s %u\n", ops[i].name, key);
+		if (atomic_read(&nvdimm->busy)) {
+			dev_dbg(dev, "Unable to secure erase while DIMM active.\n");
+			return -EBUSY;
+		}
+		rc = nvdimm_security_erase(nvdimm, key, i == OP_ERASE
+				? NVDIMM_USER : NVDIMM_MASTER);
 	} else if (i == OP_OVERWRITE) {
 		dev_dbg(dev, "overwrite %u\n", key);
+		if (atomic_read(&nvdimm->busy)) {
+			dev_dbg(dev, "Unable to overwrite while DIMM active.\n");
+			return -EBUSY;
+		}
 		rc = nvdimm_security_overwrite(nvdimm, key);
-	} else if (i == OP_MASTER_UPDATE) {
-		dev_dbg(dev, "master_update %u %u\n", key, newkey);
-		rc = nvdimm_security_update(nvdimm, key, newkey,
-				NVDIMM_MASTER);
-	} else if (i == OP_MASTER_ERASE) {
-		dev_dbg(dev, "master_erase %u\n", key);
-		rc = nvdimm_security_erase(nvdimm, key,
-				NVDIMM_MASTER);
 	} else
 		return -EINVAL;
 
diff --git a/drivers/nvdimm/security.c b/drivers/nvdimm/security.c
index 5862d0eee9db..2166e627383a 100644
--- a/drivers/nvdimm/security.c
+++ b/drivers/nvdimm/security.c
@@ -334,11 +334,6 @@  int nvdimm_security_erase(struct nvdimm *nvdimm, unsigned int keyid,
 			|| !nvdimm->sec.flags)
 		return -EOPNOTSUPP;
 
-	if (atomic_read(&nvdimm->busy)) {
-		dev_dbg(dev, "Unable to secure erase while DIMM active.\n");
-		return -EBUSY;
-	}
-
 	rc = check_security_state(nvdimm);
 	if (rc)
 		return rc;
@@ -380,11 +375,6 @@  int nvdimm_security_overwrite(struct nvdimm *nvdimm, unsigned int keyid)
 			|| !nvdimm->sec.flags)
 		return -EOPNOTSUPP;
 
-	if (atomic_read(&nvdimm->busy)) {
-		dev_dbg(dev, "Unable to overwrite while DIMM active.\n");
-		return -EBUSY;
-	}
-
 	if (dev->driver == NULL) {
 		dev_dbg(dev, "Unable to overwrite while DIMM active.\n");
 		return -EINVAL;