turbostat: Use GCC's CPUID functions to support PIC
authorJosh Triplett <josh@joshtriplett.org>
Wed, 21 Aug 2013 00:20:14 +0000 (17:20 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 13 Feb 2014 21:48:00 +0000 (13:48 -0800)
commit0e2d79ded075f612ba63178c6eaefe6ee7d8dd75
treed1890cb2b292b33af6d2a371894c5fe10c1898d6
parent73cb6cf10ef0ce902cb13b5bcb2c9c653e9a7798
turbostat: Use GCC's CPUID functions to support PIC

commit 2b92865e648ce04a39fda4f903784a5d01ecb0dc upstream.

turbostat uses inline assembly to call cpuid.  On 32-bit x86, on systems
that have certain security features enabled by default that make -fPIC
the default, this causes a build error:

turbostat.c: In function ‘check_cpuid’:
turbostat.c:1906:2: error: PIC register clobbered by ‘ebx’ in ‘asm’
  asm("cpuid" : "=a" (fms), "=c" (ecx), "=d" (edx) : "a" (1) : "ebx");
  ^

GCC provides a header cpuid.h, containing a __get_cpuid function that
works with both PIC and non-PIC.  (On PIC, it saves and restores ebx
around the cpuid instruction.)  Use that instead.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tools/power/x86/turbostat/turbostat.c