[PATCH] nvme: Ensure ret is always initialized in

From: Nathan Chancellor
Date: Fri May 06 2022 - 11:05:32 EST


Clang warns:

drivers/nvme/host/ioctl.c:674:6: error: variable 'ret' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
if (ns)
^~
drivers/nvme/host/ioctl.c:677:9: note: uninitialized use occurs here
return ret;
^~~
drivers/nvme/host/ioctl.c:674:2: note: remove the 'if' if its condition is always true
if (ns)
^~~~~~~
drivers/nvme/host/ioctl.c:672:9: note: initialize the variable 'ret' to silence this warning
int ret;
^
= 0
1 error generated.

Initialize ret to zero so that it cannot be used uninitialized.

Fixes: 271ee3df5cca ("nvme: wire-up uring-cmd support for io-passthru on char-device.")
Link: https://github.com/ClangBuiltLinux/linux/issues/1630
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
---

Or alternatively, remove the 'if (ns)' if ns can never be NULL; I tried
going down the rabbit hole to see if that is possible but I got a little
lost :^)

drivers/nvme/host/ioctl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 9db88f2c15f8..3ad5285c1f96 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -669,7 +669,7 @@ int nvme_ns_head_chr_uring_cmd(struct io_uring_cmd *ioucmd,
struct nvme_ns_head *head = container_of(cdev, struct nvme_ns_head, cdev);
int srcu_idx = srcu_read_lock(&head->srcu);
struct nvme_ns *ns = nvme_find_path(head);
- int ret;
+ int ret = 0;

if (ns)
ret = nvme_ns_uring_cmd(ns, ioucmd, issue_flags);

base-commit: 002b149a51a53facaf26d7c6f2c1fe718673683c
--
2.36.0