From 2b10906f2d25515bba58070b8183babc89063597 Mon Sep 17 00:00:00 2001 From: Brian Gerst Date: Thu, 19 Dec 2019 06:58:12 -0500 Subject: x86: Remove force_iret() force_iret() was originally intended to prevent the return to user mode with the SYSRET or SYSEXIT instructions, in cases where the register state could have been changed to be incompatible with those instructions. The entry code has been significantly reworked since then, and register state is validated before SYSRET or SYSEXIT are used. force_iret() no longer serves its original purpose and can be eliminated. Signed-off-by: Brian Gerst Signed-off-by: Borislav Petkov Acked-by: Oleg Nesterov Link: https://lkml.kernel.org/r/20191219115812.102620-1-brgerst@gmail.com --- arch/x86/include/asm/thread_info.h | 9 --------- 1 file changed, 9 deletions(-) (limited to 'arch/x86/include/asm/thread_info.h') diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index d779366ce3f8..cf4327986e98 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -239,15 +239,6 @@ static inline int arch_within_stack_frames(const void * const stack, current_thread_info()->status & TS_COMPAT) #endif -/* - * Force syscall return via IRET by making it look as if there was - * some work pending. IRET is our most capable (but slowest) syscall - * return path, which is able to restore modified SS, CS and certain - * EFLAGS values that other (fast) syscall return instructions - * are not able to restore properly. - */ -#define force_iret() set_thread_flag(TIF_NOTIFY_RESUME) - extern void arch_task_cache_init(void); extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); extern void arch_release_task_struct(struct task_struct *tsk); -- cgit v1.2.3