Commit 28f20a19 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86-urgent-2023-08-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 fixes from Ingo Molnar:
 "Fix an FPU invalidation bug on exec(), and fix a performance
  regression due to a missing setting of X86_FEATURE_OSXSAVE"

* tag 'x86-urgent-2023-08-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Set X86_FEATURE_OSXSAVE feature after enabling OSXSAVE in CR4
  x86/fpu: Invalidate FPU state correctly on exec()
parents 3b35375f 2c66ca39

arch/x86/kernel/fpu/context.h

+1 −2
Original line number Diff line number Diff line
@@ -19,8 +19,7 @@ 
 * FPU state for a task MUST let the rest of the kernel know that the

 * FPU registers are no longer valid for this task.

 *

 * Either one of these invalidation functions is enough. Invalidate

 * a resource you control: CPU if using the CPU for something else

 * Invalidate a resource you control: CPU if using the CPU for something else

 * (with preemption disabled), FPU for the current task, or a task that

 * is prevented from running by the current task.

 */

arch/x86/kernel/fpu/core.c

+1 −1
Original line number Diff line number Diff line
@@ -679,7 +679,7 @@ static void fpu_reset_fpregs(void) 
	struct fpu *fpu = &current->thread.fpu;



	fpregs_lock();

	fpu__drop(fpu);

	__fpu_invalidate_fpregs_state(fpu);

	/*

	 * This does not change the actual hardware registers. It just

	 * resets the memory image and sets TIF_NEED_FPU_LOAD so a

arch/x86/kernel/fpu/xstate.c

+7 −0
Original line number Diff line number Diff line
@@ -882,6 +882,13 @@ void __init fpu__init_system_xstate(unsigned int legacy_size) 
		goto out_disable;

	}



	/*

	 * CPU capabilities initialization runs before FPU init. So

	 * X86_FEATURE_OSXSAVE is not set. Now that XSAVE is completely

	 * functional, set the feature bit so depending code works.

	 */

	setup_force_cpu_cap(X86_FEATURE_OSXSAVE);



	print_xstate_offset_size();

	pr_info("x86/fpu: Enabled xstate features 0x%llx, context size is %d bytes, using '%s' format.\n",

		fpu_kernel_cfg.max_features,