On Thu, Nov 02, 2023 at 10:50:36AM +0300, Dan Carpenter wrote:
> [ This code is very old, but it's also very obviously buggy. Does
> anyone know what a good default "out =" value should be? - dan ]
>
> Hello Linus Torvalds,
Hi,
>
> The patch 1da177e4c3f4: "Linux-2.6.12-rc2" from Apr 16, 2005
> (linux-next), leads to the following Smatch static checker warning:
>
> drivers/infiniband/hw/mthca/mthca_cmd.c:644 mthca_SYS_EN()
> error: uninitialized symbol 'out'.
Thanks for the report, I'll send a patch after merge window.
>
> drivers/infiniband/hw/mthca/mthca_cmd.c
> 636 int mthca_SYS_EN(struct mthca_dev *dev)
> 637 {
> 638 u64 out;
> 639 int ret;
> 640
> 641 ret = mthca_cmd_imm(dev, 0, &out, 0, 0, CMD_SYS_EN, CMD_TIME_CLASS_D);
>
> We pass out here and it gets used without being initialized.
>
> err = mthca_cmd_post(dev, in_param,
> out_param ? *out_param : 0,
> ^^^^^^^^^^
> in_modifier, op_modifier,
> op, context->token, 1);
>
> It's the same in mthca_cmd_wait() and mthca_cmd_poll().
>
> 642
> 643 if (ret == -ENOMEM)
> --> 644 mthca_warn(dev, "SYS_EN DDR error: syn=%x, sock=%d, "
> 645 "sladdr=%d, SPD source=%s\n",
> 646 (int) (out >> 6) & 0xf, (int) (out >> 4) & 3,
> 647 (int) (out >> 1) & 7, (int) out & 1 ? "NVMEM" : "DIMM");
> 648
> 649 return ret;
> 650 }
>
> regards,
> dan carpenter
