Re: [PATCH 4.19 237/276] scsi: lpfc: avoid uninitialized variable warning

From: Pavel Machek
Date: Thu Jun 06 2019 - 08:57:33 EST


Hi!

> [ Upstream commit faf5a744f4f8d76e7c03912b5cd381ac8045f6ec ]
>
> clang -Wuninitialized incorrectly sees a variable being used without
> initialization:
>
> drivers/scsi/lpfc/lpfc_nvme.c:2102:37: error: variable 'localport' is uninitialized when used here
> [-Werror,-Wuninitialized]
> lport = (struct lpfc_nvme_lport *)localport->private;
> ^~~~~~~~~
> drivers/scsi/lpfc/lpfc_nvme.c:2059:38: note: initialize the variable 'localport' to silence this warning
> struct nvme_fc_local_port *localport;
> ^
> = NULL
> 1 error generated.
>
> This is clearly in dead code, as the condition leading up to it is always
> false when CONFIG_NVME_FC is disabled, and the variable is always
> initialized when nvme_fc_register_localport() got called successfully.
>
> Change the preprocessor conditional to the equivalent C construct, which
> makes the code more readable and gets rid of the warning.

Unfortunately, this missed "else" branch where the code was freeing
the memory with kfree(cstat)... so this introduces a memory leak.

Best regards,
Pavel

> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Acked-by: James Smart <james.smart@xxxxxxxxxxxx>
> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>


--
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