On Thu, Jun 06, 2019 at 09:00:42AM -0700, Nathan Chancellor wrote:
On Thu, Jun 06, 2019 at 02:53:23PM +0200, Pavel Machek wrote:
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
For the record, this is not a problem with the upstream commit (not saying you thought that or not, I just want to be clear).
Looks like commit 4c47efc140fa ("scsi: lpfc: Move SCSI and NVME Stats to hardware queue structures") "resolved" this by not making it an issue in the first place. I think the simpler fix is this.
Thanks for pointing it out!
diff --git a/drivers/scsi/lpfc/lpfc_nvme.c b/drivers/scsi/lpfc/lpfc_nvme.c index 099f70798fdd..645ffb5332b4 100644 --- a/drivers/scsi/lpfc/lpfc_nvme.c +++ b/drivers/scsi/lpfc/lpfc_nvme.c @@ -2477,14 +2477,14 @@ lpfc_nvme_create_localport(struct lpfc_vport *vport) lpfc_nvme_template.max_sgl_segments = phba->cfg_nvme_seg_cnt + 1; lpfc_nvme_template.max_hw_queues = phba->cfg_nvme_io_channel;
if (!IS_ENABLED(CONFIG_NVME_FC))return ret;cstat = kmalloc((sizeof(struct lpfc_nvme_ctrl_stat) * phba->cfg_nvme_io_channel), GFP_KERNEL); if (!cstat) return -ENOMEM;
if (!IS_ENABLED(CONFIG_NVME_FC))return ret;/* localport is allocated from the stack, but the registration * call allocates heap memory as well as the private area. */
Can you send this as a real patch that I can queue up?
thanks,
greg k-h