linux/arch/x86/include/asm/fpu
Sebastian Andrzej Siewior 383c252545 x86/entry: Add TIF_NEED_FPU_LOAD
Add TIF_NEED_FPU_LOAD. This flag is used for loading the FPU registers
before returning to userland. It must not be set on systems without a
FPU.

If this flag is cleared, the CPU's FPU registers hold the latest,
up-to-date content of the current task's (current()) FPU registers.
The in-memory copy (union fpregs_state) is not valid.

If this flag is set, then all of CPU's FPU registers may hold a random
value (except for PKRU) and it is required to load the content of the
FPU registers on return to userland.

Introduce it now as a preparatory change before adding the main feature.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190403164156.19645-17-bigeasy@linutronix.de
2019-04-11 16:21:51 +02:00
..
api.h x86/fpu: Add an __fpregs_load_activate() internal helper 2019-04-10 16:23:14 +02:00
internal.h x86/entry: Add TIF_NEED_FPU_LOAD 2019-04-11 16:21:51 +02:00
regset.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
signal.h x86/fpu: Remove fpu->initialized usage in __fpu__restore_sig() 2019-04-09 19:27:29 +02:00
types.h x86/fpu: Remove fpu->initialized 2019-04-10 15:42:40 +02:00
xstate.h x86/fpu: Eager switch PKRU state 2019-04-11 15:57:10 +02:00