From f601e6e47114629f2c477fdcad14071d58bcf062 Mon Sep 17 00:00:00 2001 From: Frank Denis Date: Fri, 2 May 2014 20:39:51 -0700 Subject: [PATCH] Preserve (e|r)bx register when calling cpuid --- src/libsodium/sodium/runtime.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/src/libsodium/sodium/runtime.c b/src/libsodium/sodium/runtime.c index 4bc200bb..f23959a6 100644 --- a/src/libsodium/sodium/runtime.c +++ b/src/libsodium/sodium/runtime.c @@ -46,10 +46,19 @@ _cpuid(unsigned int cpu_info[4U], const unsigned int cpu_info_type) #ifdef _MSC_VER __cpuidex((int *) cpu_info, cpu_info_type, 0); #elif defined(HAVE_CPUID) - __asm__ __volatile__ ("cpuid" : - "=a" (cpu_info[0]), "=b" (cpu_info[1]), +# ifdef __x86_64__ + __asm__ __volatile__ ("xchgq %%rbx, %q1; cpuid; xchgq %%rbx, %q1" : + "=a" (cpu_info[0]), "=&r" (cpu_info[1]), "=c" (cpu_info[2]), "=d" (cpu_info[3]) : "a" (cpu_info_type), "c" (0U)); +# elif defined(__i386__) + __asm__ __volatile__ ("xchgl %%ebx, %k1; cpuid; xchgl %%ebx, %k1" : + "=a" (cpu_info[0]), "=&r" (cpu_info[1]), + "=c" (cpu_info[2]), "=d" (cpu_info[3]) : + "0" (cpu_info_type), "2" (0U)); +# else + cpu_info[0] = cpu_info[1] = cpu_info[2] = cpu_info[3] = 0; +# endif #else cpu_info[0] = cpu_info[1] = cpu_info[2] = cpu_info[3] = 0; #endif