Commit 77fbcced authored Apr 09, 2025 by Ingo Molnar

x86/fpu: Introduce the x86_task_fpu() helper method



The per-task FPU context/save area is allocated right
next to task_struct, currently in a variable-size
array via task_struct::thread.fpu[], but we plan to
fully hide it from the C type scope.

Introduce the x86_task_fpu() accessor that gets to the
FPU context pointer explicitly from the task pointer.

Right now this is a simple (task)->thread.fpu wrapper.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250409211127.3544993-2-mingo@kernel.org

parent cbe8e4da

arch/x86/include/asm/processor.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -523,6 +523,8 @@ struct thread_struct {
		*/
		};

		#define x86_task_fpu(task) (&(task)->thread.fpu)

		extern void fpu_thread_struct_whitelist(unsigned long offset, unsigned long size);

		static inline void arch_thread_struct_whitelist(unsigned long *offset,