diff options
Diffstat (limited to 'arch/x86/include/asm/cpuid.h')
| -rw-r--r-- | arch/x86/include/asm/cpuid.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/x86/include/asm/cpuid.h b/arch/x86/include/asm/cpuid.h index 6b122a31da06..80cc6386d7b1 100644 --- a/arch/x86/include/asm/cpuid.h +++ b/arch/x86/include/asm/cpuid.h @@ -196,7 +196,12 @@ static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves) for_each_possible_hypervisor_cpuid_base(base) { cpuid(base, &eax, &signature[0], &signature[1], &signature[2]); - if (!memcmp(sig, signature, 12) && + /* + * This must not compile to "call memcmp" because it's called + * from PVH early boot code before instrumentation is set up + * and memcmp() itself may be instrumented. + */ + if (!__builtin_memcmp(sig, signature, 12) && (leaves == 0 || ((eax - base) >= leaves))) return base; } |