Sorry for the late reply :) On 2018/11/16 1:22, Borislav Petkov wrote: >> @@ -640,7 +641,7 @@ static int find_num_cache_leaves(struct cpuinfo_x86 *c) >> /* Do cpuid(op) loop to find out num_cache_leaves */ >> cpuid_count(op, i, &eax, &ebx, &ecx, &edx); >> cache_eax.full = eax; >> - } while (cache_eax.split.type != CTYPE_NULL); >> + } while (cache_eax.split.type != CTYPE_NULL && i != CTYPE_MAX); > i is an int and CTYPE_MAX is enum _cache_type. Huh?
How about define CTYPE_MAX like this: #define CTYPE_MAX 4 > This works by chance because CTYPE_MAX is 4 and the termination CPUID > leaf is the 4th too. It will return CTYPE_NULL when accessing the 4th CPUID leaf in most of the cases, but in certain case it will not. So I think it's better to restrict the maximum CPUID access times to 4 for kernel robustness. -- Regards, Pu Wen
