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| author | Krzysztof Helt <krzysztof.h1@wp.pl> | 2008-07-31 23:43:44 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-31 23:56:27 +0200 |
| commit | e0d22d03c06c4e2c194d7010bc1e4a972199f156 (patch) | |
| tree | 414e81fefd2c44dfbee7509d54aa372845949013 /arch | |
| parent | 8978b74253280d59e97cf49a3ec2c0cbccd5b801 (diff) | |
| download | linux-e0d22d03c06c4e2c194d7010bc1e4a972199f156.tar.gz linux-e0d22d03c06c4e2c194d7010bc1e4a972199f156.tar.bz2 linux-e0d22d03c06c4e2c194d7010bc1e4a972199f156.zip | |
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')
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 6 |
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"); } |