Re: [bug report] arch_topology: Build cacheinfo from primary CPU

[Pierre Gondois <pierre.gondois@arm.com>]

Hello Dan,
The 'levels' and 'split_levels' variables are initialized through their
addresses when necessary, so I believe the warning can be ignored.

If you still want to have the variables initialized, please let me know and I
will send a patch,

Regards,
Pierre

On 1/23/23 16:07, Dan Carpenter wrote:
> Hello Pierre Gondois,
> 
> The patch 5944ce092b97: "arch_topology: Build cacheinfo from primary
> CPU" from Jan 4, 2023, leads to the following Smatch static checker
> warning:
> 
> drivers/base/cacheinfo.c:440 fetch_cache_info()	error: uninitialized symbol 'levels'.
> drivers/base/cacheinfo.c:447 fetch_cache_info() error: uninitialized symbol 'split_levels'.
> 
> drivers/base/cacheinfo.c
>      424 int fetch_cache_info(unsigned int cpu)
>      425 {
>      426         struct cpu_cacheinfo *this_cpu_ci;
>      427         unsigned int levels, split_levels;
>      428         int ret;
>      429
>      430         if (acpi_disabled) {
>      431                 ret = init_of_cache_level(cpu);
>      432                 if (ret < 0)
>      433                         return ret;
>      434         } else {
>      435                 ret = acpi_get_cache_info(cpu, &levels, &split_levels);
>      436                 if (ret < 0)
>      437                         return ret;
> 
> Apparently, I must have CONFIG_ACPI_PPTT disabled.
> 
>      438
>      439                 this_cpu_ci = get_cpu_cacheinfo(cpu);
> --> 440                 this_cpu_ci->num_levels = levels;
>                                                    ^^^^^^
> Unititialized.
> 
>      441                 /*
>      442                  * This assumes that:
>      443                  * - there cannot be any split caches (data/instruction)
>      444                  *   above a unified cache
>      445                  * - data/instruction caches come by pair
>      446                  */
>      447                 this_cpu_ci->num_leaves = levels + split_levels;
>      448         }
>      449         if (!cache_leaves(cpu))
>      450                 return -ENOENT;
>      451
>      452         return allocate_cache_info(cpu);
>      453 }
> 
> regards,
> dan carpenter