Replace cpuid asm statement with __cpuid_count

The compiler doesn't know that the cpuid asm statement in intel_check_word
will trash RBX.  We are lucky that it doesn't cause any problems since
RBX is also used by compiler for other purposes so that RBX is saved and
restored.  This patch replaces it with __cpuid_count.

	[BZ #17259]
	* sysdeps/x86_64/cacheinfo.c (intel_check_word): Replace cpuid
	asm statement with __cpuid_count.

diff --git a/ChangeLog b/ChangeLog
index d385cc9..e3a1f0a 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-08-12  H.J. Lu  <hongjiu.lu@intel.com>
+
+       [BZ #17259]
+       * sysdeps/x86_64/cacheinfo.c (intel_check_word): Replace cpuid
+       asm statement with __cpuid_count.
+
 2014-08-12  Mike Frysinger  <vapier@gentoo.org>
 
        * configure.ac: Change __ehdr_start code to dereference the struct.

diff --git a/NEWS b/NEWS
index ad337e8..03132e2 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -22,7 +22,8 @@ Version 2.20
   16918, 16922, 16927, 16928, 16932, 16943, 16958, 16965, 16966, 16967,
   16977, 16978, 16984, 16990, 16996, 17009, 17022, 17031, 17042, 17048,
   17050, 17058, 17061, 17062, 17069, 17075, 17078, 17079, 17084, 17086,
-  17088, 17092, 17097, 17125, 17135, 17137, 17150, 17153, 17213, 17261.
+  17088, 17092, 17097, 17125, 17135, 17137, 17150, 17153, 17213, 17259,
+  17261.
 
 * Reverted change of ABI data structures for s390 and s390x:
   On s390 and s390x the size of struct ucontext and jmp_buf was increased in

diff --git a/sysdeps/x86_64/cacheinfo.c b/sysdeps/x86_64/cacheinfo.c
index 163af2a..ca13a53 100644 (file)
--- a/sysdeps/x86_64/cacheinfo.c
+++ b/sysdeps/x86_64/cacheinfo.c
@@ -191,9 +191,7 @@ intel_check_word (int name, unsigned int value, bool *has_level_2,
          unsigned int round = 0;
          while (1)
            {
-             asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1"
-                           : "=a" (eax), "=r" (ebx), "=c" (ecx), "=d" (edx)
-                           : "0" (4), "2" (round));
+             __cpuid_count (4, round, eax, ebx, ecx, edx);
 
              enum { null = 0, data = 1, inst = 2, uni = 3 } type = eax & 0x1f;
              if (type == null)