From 35ac2d7ba787eb4b7418a5a6f5919c25e10a780a Mon Sep 17 00:00:00 2001 From: Yu-cheng Yu Date: Mon, 11 Jul 2016 09:18:56 -0700 Subject: x86/fpu/xstate: Fix fpstate_init() for XRSTORS In XSAVES mode if fpstate_init() is used to initialize a task's extended state area, xsave.header.xcomp_bv[63] must be set. Otherwise, when the task is scheduled, a warning is triggered from copy_kernel_to_xregs(). One such test case is: setting an invalid extended state through PTRACE. When xstateregs_set() rejects the syscall and re-initializes the task's extended state area. This triggers the warning mentioned above. Signed-off-by: Yu-cheng Yu Signed-off-by: Fenghua Yu Reviewed-by: Dave Hansen Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Ravi V Shankar Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1468253937-40008-4-git-send-email-fenghua.yu@intel.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/fpu/types.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/x86/include/asm/fpu') diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 12dd648735b6..48df486b02f9 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -231,6 +231,12 @@ struct xstate_header { u64 reserved[6]; } __attribute__((packed)); +/* + * xstate_header.xcomp_bv[63] indicates that the extended_state_area + * is in compacted format. + */ +#define XCOMP_BV_COMPACTED_FORMAT ((u64)1 << 63) + /* * This is our most modern FPU state format, as saved by the XSAVE * and restored by the XRSTOR instructions. -- cgit