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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-08-26 10:57:29 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-08-26 10:57:29 -0700 |
| commit | 28f20a19294da7df158dfca259d0e2b5866baaf9 (patch) | |
| tree | c9b64bc57b8c13c6caabbb53fdc39ff03c841e4f | |
| parent | 3b35375f19fe87b5d8822ce01f917095d575ee28 (diff) | |
| parent | 2c66ca3949dc701da7f4c9407f2140ae425683a5 (diff) | |
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()
| -rw-r--r-- | arch/x86/kernel/fpu/context.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 7 |
3 files changed, 9 insertions, 3 deletions
diff --git a/arch/x86/kernel/fpu/context.h b/arch/x86/kernel/fpu/context.h index af5cbdd9bd29..f6d856bd50bc 100644 --- a/arch/x86/kernel/fpu/context.h +++ b/arch/x86/kernel/fpu/context.h @@ -19,8 +19,7 @@ * FPU state for a task MUST let the rest of the kernel know that the * FPU registers are no longer valid for this task.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. */ diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 1015af1ae562..98e507cc7d34 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -679,7 +679,7 @@ static void fpu_reset_fpregs(void) struct fpu *fpu = ¤t->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 diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 0bab497c9436..1afbc4866b10 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -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, |