Commit-ID: 530b37e43ce3f0bb9969308c0a64901b442f8e0a Gitweb: http://git.kernel.org/tip/530b37e43ce3f0bb9969308c0a64901b442f8e0a Author: Ingo Molnar <mingo@xxxxxxxxxx> AuthorDate: Sat, 25 Apr 2015 08:27:44 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Tue, 19 May 2015 15:47:43 +0200 x86/fpu: Do CLTS fpu__init_system() 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@xxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> 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> --- 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 2752b4b..567e7e6 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.) */ -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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