Re: [PATCH V2 2/3] perf/x86/intel/uncore: Record the size of mapped area

From: Liang, Kan
Date: Thu May 28 2020 - 09:44:50 EST

On 5/28/2020 9:29 AM, Andi Kleen wrote:
On Thu, May 28, 2020 at 06:15:26AM -0700, kan.liang@xxxxxxxxxxxxxxx wrote:
- box->io_addr = ioremap(addr, SNB_UNCORE_PCI_IMC_MAP_SIZE);
+ if (!type->mmio_map_size) {
+ pr_warn("perf uncore: Cannot ioremap for %s. Size of map area is 0.\n",
+ type->name);
+ return;
+ }

Is that likely that the size is 0?

In case someone forgets to set mmio_map_size.

In any case you have to test the return value of ioremap. So I would rather
test the address for 0 than the size.

The box->io_addr is checked now, but there is no warning message.
I will remove the check for mmio_map_size, and add a warning message for the check of box->io_addr.