From 100c99a49a6f2288c668b2f416eb33688bc78fc8 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 BugLink: https://bugs.launchpad.net/bugs/1967750 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 (cherry picked from commit 2dd8eedc80b184bb16aad697ae60367c5bf07299) Acked-by: Dimitri John Ledkov Signed-off-by: Andrea Righi --- 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 f6cf20ebc280..58e6a2f1ea99 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 { @@ -538,12 +535,12 @@ 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 14560fda15c2..c6df97517ec8 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -404,6 +404,16 @@ int fpu_clone(struct task_struct *dst) return 0; } +/* + * 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 diff --git a/arch/x86/kernel/fpu/internal.h b/arch/x86/kernel/fpu/internal.h index e1d8a352f12d..5c4f71ff6ae9 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 */ -- 2.39.5