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authorKrzysztof Helt <krzysztof.h1@wp.pl>2008-07-31 23:43:44 +0200
committerIngo Molnar <mingo@elte.hu>2008-07-31 23:56:27 +0200
commite0d22d03c06c4e2c194d7010bc1e4a972199f156 (patch)
tree414e81fefd2c44dfbee7509d54aa372845949013 /arch/x86
parent8978b74253280d59e97cf49a3ec2c0cbccd5b801 (diff)
x86: fdiv bug detection fix
The fdiv detection code writes s32 integer into the boot_cpu_data.fdiv_bug. However, the boot_cpu_data.fdiv_bug is only char (s8) field so the detection overwrites already set fields for other bugs, e.g. the f00f bug field. Use local s32 variable to receive result. This is a partial fix to Bugzilla #9928 - fixes wrong information about the f00f bug (tested) and probably for coma bug (I have no cpu to test this). Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/cpu/bugs.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index c9b58a806e85..c8e315f1aa83 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -50,6 +50,8 @@ static double __initdata y = 3145727.0;
*/
static void __init check_fpu(void)
{
+ s32 fdiv_bug;
+
if (!boot_cpu_data.hard_math) {
#ifndef CONFIG_MATH_EMULATION
printk(KERN_EMERG "No coprocessor found and no math emulation present.\n");
@@ -74,8 +76,10 @@ static void __init check_fpu(void)
"fistpl %0\n\t"
"fwait\n\t"
"fninit"
- : "=m" (*&boot_cpu_data.fdiv_bug)
+ : "=m" (*&fdiv_bug)
: "m" (*&x), "m" (*&y));
+
+ boot_cpu_data.fdiv_bug = fdiv_bug;
if (boot_cpu_data.fdiv_bug)
printk("Hmm, FPU with FDIV bug.\n");
}