Messages in this thread Patch in this message | | | Date | Thu, 10 Mar 2016 03:04:40 -0800 | From | tip-bot for Andy Lutomirski <> | Subject | [tip:x86/asm] x86/entry: Remove TIF_SINGLESTEP entry work |
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Commit-ID: 392a62549fbb80da48811d04391615a25c39d091 Gitweb: http://git.kernel.org/tip/392a62549fbb80da48811d04391615a25c39d091 Author: Andy Lutomirski <luto@kernel.org> AuthorDate: Wed, 9 Mar 2016 19:00:34 -0800 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Thu, 10 Mar 2016 09:48:14 +0100
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: 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 | 10 ---------- arch/x86/include/asm/thread_info.h | 2 +- 2 files changed, 1 insertion(+), 11 deletions(-)
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 1a000f5..209ba33 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -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 diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index c0778fc..f2e2302 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -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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