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 <[email protected]>
Signed-off-by: Nathan Chancellor <[email protected]>
---
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
Ugh, subject should be:
nvme: Ensure ret is always initialized in nvme_ns_head_chr_uring_cmd()
I can resend if this is the correct thing to do.
On Fri, May 06, 2022 at 08:03:58AM -0700, Nathan Chancellor wrote:
> 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 <[email protected]>
> Signed-off-by: Nathan Chancellor <[email protected]>
> ---
>
> 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
>