Messages in this thread Patch in this message | | | From | Ingo Molnar <> | Subject | [PATCH 111/208] x86/fpu: Do CLTS fpu__init_system() | Date | Tue, 5 May 2015 19:50:03 +0200 |
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mxcsr_feature_mask_init() depends on TS being cleared, as it executes an FXSAVE instruction.
After later changes we will move the TS setup into fpu__init_cpu(), which will interact with this - so clear the TS flag explicitly.
Reviewed-by: Borislav Petkov <bp@alien8.de> Cc: Andy Lutomirski <luto@amacapital.net> 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: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/kernel/fpu/init.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 2752b4bae854..567e7e6cdc6b 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -214,6 +214,13 @@ void fpu__init_system(void) fpu__init_cpu(); /* + * But don't leave CR0::TS set yet, as some of the FPU setup methods depend + * on being able to execute FPU instructions that will fault on a set TS, + * such as the FXSAVE in mxcsr_feature_mask_init(). + */ + clts(); + + /* * Set up the legacy init FPU context. (xstate init might overwrite this * with a more modern format, if the CPU supports it.) */ -- 2.1.0
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