From 9e798e9aa14c45fb94e47b30bf6347b369ce9df7 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 21 Oct 2021 15:55:14 -0700 Subject: x86/fpu: Prepare fpu_clone() for dynamically enabled features The default portion of the parent's FPU state is saved in a child task. With dynamic features enabled, the non-default portion is not saved in a child's fpstate because these register states are defined to be caller-saved. The new task's fpstate is therefore the default buffer. Fork inherits the permission of the parent. Also, do not use memcpy() when TIF_NEED_FPU_LOAD is set because it is invalid when the parent has dynamic features. Signed-off-by: Thomas Gleixner Signed-off-by: Chang S. Bae Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20211021225527.10184-11-chang.seok.bae@intel.com --- arch/x86/kernel/process.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kernel/process.c') diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 97fea1649a5e..99025e32f105 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -157,7 +157,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg, frame->flags = X86_EFLAGS_FIXED; #endif - fpu_clone(p); + fpu_clone(p, clone_flags); /* Kernel thread ? */ if (unlikely(p->flags & PF_KTHREAD)) { -- cgit v1.2.3