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Commit 392a6254 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Ingo Molnar
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x86/entry: Remove TIF_SINGLESTEP entry work 



Now that SYSENTER with TF set puts X86_EFLAGS_TF directly into
regs->flags, we don't need a TIF_SINGLESTEP fixup in the syscall
entry code.  Remove it.

Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/2d15f24da52dafc9d2f0b8d76f55544f4779c517.1457578375.git.luto@kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 2a41aa4f

arch/x86/entry/common.c

+0 −10
Original line number Diff line number Diff line
@@ -172,16 +172,6 @@ long syscall_trace_enter_phase2(struct pt_regs *regs, u32 arch, 
	if (IS_ENABLED(CONFIG_DEBUG_ENTRY))

		BUG_ON(regs != task_pt_regs(current));



	/*

	 * If we stepped into a sysenter/syscall insn, it trapped in

	 * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.

	 * If user-mode had set TF itself, then it's still clear from

	 * do_debug() and we need to set it again to restore the user

	 * state.  If we entered on the slow path, TF was already set.

	 */

	if (work & _TIF_SINGLESTEP)

		regs->flags |= X86_EFLAGS_TF;



#ifdef CONFIG_SECCOMP

	/*

	 * Call seccomp_phase2 before running the other hooks so that

arch/x86/include/asm/thread_info.h

+1 −1
Original line number Diff line number Diff line
@@ -137,7 +137,7 @@ struct thread_info { 
/* work to do in syscall_trace_enter() */

#define _TIF_WORK_SYSCALL_ENTRY	\

	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT |	\

	 _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT |	\

	 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT |	\

	 _TIF_NOHZ)



/* work to do on any return to user space */