From 2dd8eedc80b184bb16aad697ae60367c5bf07299 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 13 Oct 2021 16:55:45 +0200 Subject: [PATCH] x86/process: Move arch_thread_struct_whitelist() out of line In preparation for dynamically enabled FPU features move the function out of line as the goal is to expose less and not more information. Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20211013145322.869001791@linutronix.de --- arch/x86/include/asm/processor.h | 9 +++------ arch/x86/kernel/fpu/core.c | 10 ++++++++++ arch/x86/kernel/fpu/internal.h | 2 ++ 3 files changed, 15 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 4519d33..1bd3e8d 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -461,9 +461,6 @@ DECLARE_PER_CPU(struct irq_stack *, hardirq_stack_ptr); DECLARE_PER_CPU(struct irq_stack *, softirq_stack_ptr); #endif /* !X86_64 */ -extern unsigned int fpu_kernel_xstate_size; -extern unsigned int fpu_user_xstate_size; - struct perf_event; struct thread_struct { @@ -537,12 +534,12 @@ struct thread_struct { */ }; -/* Whitelist the FPU register state from the task_struct for hardened usercopy. */ +extern void fpu_thread_struct_whitelist(unsigned long *offset, unsigned long *size); + static inline void arch_thread_struct_whitelist(unsigned long *offset, unsigned long *size) { - *offset = offsetof(struct thread_struct, fpu.__fpstate.regs); - *size = fpu_kernel_xstate_size; + fpu_thread_struct_whitelist(offset, size); } static inline void diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 14560fd..c6df975 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -405,6 +405,16 @@ int fpu_clone(struct task_struct *dst) } /* + * Whitelist the FPU register state embedded into task_struct for hardened + * usercopy. + */ +void fpu_thread_struct_whitelist(unsigned long *offset, unsigned long *size) +{ + *offset = offsetof(struct thread_struct, fpu.__fpstate.regs); + *size = fpu_kernel_xstate_size; +} + +/* * Drops current FPU state: deactivates the fpregs and * the fpstate. NOTE: it still leaves previous contents * in the fpregs in the eager-FPU case. diff --git a/arch/x86/kernel/fpu/internal.h b/arch/x86/kernel/fpu/internal.h index e1d8a35..5c4f71f 100644 --- a/arch/x86/kernel/fpu/internal.h +++ b/arch/x86/kernel/fpu/internal.h @@ -2,6 +2,8 @@ #ifndef __X86_KERNEL_FPU_INTERNAL_H #define __X86_KERNEL_FPU_INTERNAL_H +extern unsigned int fpu_kernel_xstate_size; +extern unsigned int fpu_user_xstate_size; extern struct fpstate init_fpstate; /* CPU feature check wrappers */ -- 2.7.4