[PATCH] nvme: work around -Wformat-security warning

[Arnd Bergmann <arnd@kernel.org>]

From: Arnd Bergmann <arnd@arndb.de>

Passing a string variable into dev_set_name() causes a warning
when building with -Wformat-security enabled:

drivers/nvme/host/core.c: In function 'nvme_cdev_add':
drivers/nvme/host/core.c:3911:9: error: format not a string literal and no format arguments [-Werror=format-security]
 3911 |         ret = dev_set_name(cdev_device, name);

Remove the temporary strings and let dev_set_name() do the
same thing internally.

Fixes: 26acdaa357cd ("nvme: fix crash and memory leak during invalid cdev teardown")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/nvme/host/core.c      | 21 +++++++++------------
 drivers/nvme/host/multipath.c | 12 +++++-------
 drivers/nvme/host/nvme.h      |  6 +++---
 3 files changed, 17 insertions(+), 22 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index beea23d04a70..79f6a2c7923e 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3931,9 +3931,9 @@ void nvme_cdev_del(struct cdev *cdev, struct device *cdev_device)
 	put_device(cdev_device);
 }
 
-int nvme_cdev_add(const char *name, struct cdev *cdev,
-		struct device *cdev_device,
-		const struct file_operations *fops, struct module *owner)
+int nvme_cdev_add(struct cdev *cdev, struct device *cdev_device,
+		const struct file_operations *fops, struct module *owner,
+		int ctrl, int head)
 {
 	int minor, ret;
 
@@ -3941,7 +3941,7 @@ int nvme_cdev_add(const char *name, struct cdev *cdev,
 	if (minor < 0)
 		return minor;
 
-	ret = dev_set_name(cdev_device, name);
+	ret = dev_set_name(cdev_device, "ng%dn%d", ctrl, head);
 	if (ret) {
 		ida_free(&nvme_ns_chr_minor_ida, minor);
 		return ret;
@@ -3982,17 +3982,14 @@ static const struct file_operations nvme_ns_chr_fops = {
 
 static void nvme_add_ns_cdev(struct nvme_ns *ns)
 {
-	char name[32];
-
 	ns->cdev_device.parent = ns->ctrl->device;
-	snprintf(name, sizeof(name), "ng%dn%d", ns->ctrl->instance,
-		 ns->head->instance);
 
 	nvme_get_ns(ns); /* Undone in nvme_cdev_rel() */
-	if (nvme_cdev_add(name, &ns->cdev, &ns->cdev_device,
-			&nvme_ns_chr_fops, ns->ctrl->ops->module)) {
-		dev_err(ns->ctrl->device, "Unable to create the %s device\n",
-			name);
+	if (nvme_cdev_add(&ns->cdev, &ns->cdev_device,
+			&nvme_ns_chr_fops, ns->ctrl->ops->module,
+			ns->ctrl->instance, ns->head->instance)) {
+		dev_err(ns->ctrl->device, "Unable to create the ng%dn%d device\n",
+			ns->ctrl->instance, ns->head->instance);
 		nvme_put_ns(ns);
 		return;
 	}
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 75dbb58286a3..3d46c4f28a47 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -646,17 +646,15 @@ static const struct file_operations nvme_ns_head_chr_fops = {
 
 static void nvme_add_ns_head_cdev(struct nvme_ns_head *head)
 {
-	char name[32];
-
 	head->cdev_device.parent = &head->subsys->dev;
-	snprintf(name, sizeof(name), "ng%dn%d", head->subsys->instance,
-		 head->instance);
 
 	nvme_get_ns_head(head); /* Undone in nvme_cdev_rel() */
-	if (nvme_cdev_add(name, &head->cdev, &head->cdev_device,
-			&nvme_ns_head_chr_fops, THIS_MODULE)) {
+	if (nvme_cdev_add(&head->cdev, &head->cdev_device,
+			&nvme_ns_head_chr_fops, THIS_MODULE,
+			head->subsys->instance, head->instance)) {
 		dev_err(disk_to_dev(head->disk),
-			"Unable to create the %s device\n", name);
+			"Unable to create the ng%dn%d device\n",
+			head->subsys->instance, head->instance);
 		nvme_put_ns_head(head);
 		return;
 	}
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 2cff9fcbf740..e0260f4d24fd 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -1013,9 +1013,9 @@ int nvme_get_log(struct nvme_ctrl *ctrl, u32 nsid, u8 log_page, u8 lsp, u8 csi,
 void nvme_get_ns_head(struct nvme_ns_head *head);
 bool nvme_tryget_ns_head(struct nvme_ns_head *head);
 void nvme_put_ns_head(struct nvme_ns_head *head);
-int nvme_cdev_add(const char *name, struct cdev *cdev,
-		struct device *cdev_device,
-		const struct file_operations *fops, struct module *owner);
+int nvme_cdev_add(struct cdev *cdev, struct device *cdev_device,
+		const struct file_operations *fops, struct module *owner,
+		int ctrl, int head);
 void nvme_cdev_del(struct cdev *cdev, struct device *cdev_device);
 int nvme_ioctl(struct block_device *bdev, blk_mode_t mode,
 		unsigned int cmd, unsigned long arg);
-- 
2.53.0