3.16.58-rc1 review patch. If anyone has any objections, please let me know.
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From: Ingo Molnar mingo@kernel.org
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@amacapital.net Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: Fenghua Yu fenghua.yu@intel.com Cc: H. Peter Anvin hpa@zytor.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Oleg Nesterov oleg@redhat.com Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Ben Hutchings ben@decadent.org.uk --- 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);