3.16.58-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Ingo Molnar <mingo@xxxxxxxxxx>
commit d364a7656c1855c940dfa4baf4ebcc3c6a9e6fd2 upstream.
I tried to simulate an ancient CPU via this option, and
found that it still has fxsr_opt enabled, confusing the
FPU code.
Make the 'nofxsr' option also clear FXSR_OPT flag.
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/common.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -199,6 +199,15 @@ static int __init x86_noinvpcid_setup(ch
}
early_param("noinvpcid", x86_noinvpcid_setup);
+static int __init x86_fxsr_setup(char *s)
+{
+ setup_clear_cpu_cap(X86_FEATURE_FXSR);
+ setup_clear_cpu_cap(X86_FEATURE_FXSR_OPT);
+ setup_clear_cpu_cap(X86_FEATURE_XMM);
+ return 1;
+}
+__setup("nofxsr", x86_fxsr_setup);
+
#ifdef CONFIG_X86_32
static int cachesize_override = -1;
static int disable_x86_serial_nr = 1;
@@ -210,14 +219,6 @@ static int __init cachesize_setup(char *
}
__setup("cachesize=", cachesize_setup);
-static int __init x86_fxsr_setup(char *s)
-{
- setup_clear_cpu_cap(X86_FEATURE_FXSR);
- setup_clear_cpu_cap(X86_FEATURE_XMM);
- return 1;
-}
-__setup("nofxsr", x86_fxsr_setup);
-
static int __init x86_sep_setup(char *s)
{
setup_clear_cpu_cap(X86_FEATURE_SEP);
