x86/entry: Remove TIF_SINGLESTEP entry work (392a6254) · Commits · 戴 / test

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:

Andy 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:

Ingo Molnar <mingo@kernel.org>

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 */

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