Messages in this thread Patch in this message | | | From | "Chang S. Bae" <> | Subject | [RFC PATCH 16/22] x86/fpu/xstate: Support dynamic user state in the signal handling path | Date | Thu, 1 Oct 2020 13:39:07 -0700 |
| |
Entering a signal handler, the kernel saves XSAVE area. The dynamic user state is better to be saved only when used. fpu->state_mask can help to exclude unused states.
Returning from signal handler, XRSTOR re-initializes the excluded state components.
No functional change until the kernel actually supports the dynamic user states.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Reviewed-by: Len Brown <len.brown@intel.com> Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org --- arch/x86/include/asm/fpu/internal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index f5dbbaa060fb..fd044b31ce40 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -368,7 +368,7 @@ static inline void copy_kernel_to_xregs(struct xregs_state *xstate, u64 mask) */ static inline int copy_xregs_to_user(struct xregs_state __user *buf) { - u64 mask = xfeatures_mask_user(); + u64 mask = current->thread.fpu.state_mask; u32 lmask = mask; u32 hmask = mask >> 32; int err; -- 2.17.1
| |