ba0593bf553c450a03dbc5f8c1f0ff58b778a0c8 cleared the aforementioned
cpuid bit only on 32-bit due to various problems with Virtual PC. This
somehow got lost during the 32- + 64-bit merge so restore the feature
bit on 64-bit. For that, set it explicitly for non-constant arguments of
cpu_has(). Update comment for future reference.
Signed-off-by: Borislav Petkov <bp@alien8.de>
---
arch/x86/kernel/cpu/common.c | 15 ++++++++++-----
1 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index caa967d..4b68bda 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -704,16 +704,21 @@ void __init early_cpu_init(void)
}
/*
- * The NOPL instruction is supposed to exist on all CPUs with
- * family >= 6; unfortunately, that's not true in practice because
- * of early VIA chips and (more importantly) broken virtualizers that
- * are not easy to detect. In the latter case it doesn't even *fail*
- * reliably, so probing for it doesn't even work. Disable it completely
+ * The NOPL instruction is supposed to exist on all CPUs of family >= 6;
+ * unfortunately, that's not true in practice because of early VIA
+ * chips and (more importantly) broken virtualizers that are not easy
+ * to detect. In the latter case it doesn't even *fail* reliably, so
+ * probing for it doesn't even work. Disable it completely on 32-bit
* unless we can find a reliable way to detect all the broken cases.
+ * Enable it explicitly on 64-bit for non-constant inputs of cpu_has().
*/
static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
{
+#ifdef CONFIG_X86_32
clear_cpu_cap(c, X86_FEATURE_NOPL);
+#else
+ set_cpu_cap(c, X86_FEATURE_NOPL);
+#endif
}
static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
--
1.7.2.3
--
Regards/Gruss,
Boris.
--
