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From 4c6552d2df2912a710cab6acf476347a7fbf15a0 Mon Sep 17 00:00:00 2001
From: Natanael Copa <ncopa@alpinelinux.org>
Date: Wed, 1 Sep 2010 09:12:44 +0000
Subject: [PATCH] Support for Position Independet Code by aboid clobbering PIC register
Do not use the PIC register (ebx)
See http://www.gentoo.org/proj/en/hardened/pic-fix-guide.xml#doc_chap5
---
utils/cpuid.h | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/utils/cpuid.h b/utils/cpuid.h
index 2bac69a..ebcec7c 100644
--- a/utils/cpuid.h
+++ b/utils/cpuid.h
@@ -5,9 +5,12 @@ static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
unsigned int *ecx, unsigned int *edx)
{
/* ecx is often an input as well as an output. */
- asm volatile("cpuid"
+ asm volatile(
+ "movl %%ebx, %%esi;"
+ "cpuid;"
+ "xchg %%ebx, %%esi;"
: "=a" (*eax),
- "=b" (*ebx),
+ "=S" (*ebx),
"=c" (*ecx),
"=d" (*edx)
: "0" (*eax), "2" (*ecx));
--
1.7.2.2
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