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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Steven Rostedt <rostedt@goodmis.org>,
	Brian Gerst <brgerst@gmail.com>, Juergen Gross <jgross@suse.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Arnd Bergmann <arnd@arndb.de>
Subject: [patch 5/8] x86/entry/common: Provide trace/kprobe safe exit to user space functions
Date: Tue, 25 Feb 2020 23:08:06 +0100	[thread overview]
Message-ID: <20200225221305.719921962@linutronix.de> (raw)
In-Reply-To: 20200225220801.571835584@linutronix.de

Split prepare_enter_to_user_mode() and mark it notrace/noprobe so the irq
flags tracing on return can be put into it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/entry/common.c |   15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -196,7 +196,7 @@ static void exit_to_usermode_loop(struct
 }
 
 /* Called with IRQs disabled. */
-__visible inline void prepare_exit_to_usermode(struct pt_regs *regs)
+static inline void __prepare_exit_to_usermode(struct pt_regs *regs)
 {
 	struct thread_info *ti = current_thread_info();
 	u32 cached_flags;
@@ -241,6 +241,12 @@ static void exit_to_usermode_loop(struct
 	mds_user_clear_cpu_buffers();
 }
 
+__visible inline notrace void prepare_exit_to_usermode(struct pt_regs *regs)
+{
+	__prepare_exit_to_usermode(regs);
+}
+NOKPROBE_SYMBOL(prepare_exit_to_usermode);
+
 #define SYSCALL_EXIT_WORK_FLAGS				\
 	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT |	\
 	 _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT)
@@ -271,7 +277,7 @@ static void syscall_slow_exit_work(struc
  * Called with IRQs on and fully valid regs.  Returns with IRQs off in a
  * state such that we can immediately switch to user mode.
  */
-__visible inline void syscall_return_slowpath(struct pt_regs *regs)
+__visible inline notrace void syscall_return_slowpath(struct pt_regs *regs)
 {
 	struct thread_info *ti = current_thread_info();
 	u32 cached_flags = READ_ONCE(ti->flags);
@@ -292,8 +298,9 @@ static void syscall_slow_exit_work(struc
 		syscall_slow_exit_work(regs, cached_flags);
 
 	local_irq_disable();
-	prepare_exit_to_usermode(regs);
+	__prepare_exit_to_usermode(regs);
 }
+NOKPROBE_SYMBOL(syscall_return_slowpath);
 
 #ifdef CONFIG_X86_64
 static __always_inline
@@ -417,7 +424,7 @@ static __always_inline long do_fast_sysc
 		/* User code screwed up. */
 		local_irq_disable();
 		regs->ax = -EFAULT;
-		prepare_exit_to_usermode(regs);
+		__prepare_exit_to_usermode(regs);
 		return 0;	/* Keep it simple: use IRET. */
 	}
 


  parent reply	other threads:[~2020-02-25 23:30 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-25 22:08 [patch 0/8] x86/entry: Consolidation - Part II Thomas Gleixner
2020-02-25 22:08 ` [patch 1/8] x86/entry/64: Trace irqflags unconditionally on when returing to user space Thomas Gleixner
2020-02-27 19:49   ` Borislav Petkov
2020-02-27 22:45   ` Frederic Weisbecker
2020-02-28  8:58   ` Alexandre Chartre
2020-02-25 22:08 ` [patch 2/8] x86/entry/common: Consolidate syscall entry code Thomas Gleixner
2020-02-27 19:57   ` Borislav Petkov
2020-02-27 22:52   ` Frederic Weisbecker
2020-02-28  8:59   ` Alexandre Chartre
2020-02-25 22:08 ` [patch 3/8] x86/entry/common: Mark syscall entry points notrace/nokprobe Thomas Gleixner
2020-02-27 23:15   ` Frederic Weisbecker
2020-02-28  8:59   ` Alexandre Chartre
2020-02-25 22:08 ` [patch 4/8] x86/entry: Move irq tracing on syscall entry to C-code Thomas Gleixner
2020-02-26  5:43   ` Andy Lutomirski
2020-02-26  8:17     ` Peter Zijlstra
2020-02-26 11:20       ` Andy Lutomirski
2020-02-26 19:51         ` Thomas Gleixner
2020-02-29 14:44           ` Thomas Gleixner
2020-02-29 19:25             ` Andy Lutomirski
2020-02-29 23:58               ` Steven Rostedt
2020-03-01 10:16                 ` Thomas Gleixner
2020-03-01 14:37                   ` Andy Lutomirski
2020-03-01 15:21                     ` Thomas Gleixner
2020-03-01 16:00                       ` Andy Lutomirski
2020-03-01 18:12                         ` Thomas Gleixner
2020-03-01 18:26                           ` Paul E. McKenney
2020-03-01 18:54                             ` Andy Lutomirski
2020-03-01 19:30                               ` Paul E. McKenney
2020-03-01 19:39                                 ` Andy Lutomirski
2020-03-01 20:18                                   ` Paul E. McKenney
2020-03-02  0:35                                   ` Steven Rostedt
2020-03-02  6:47                                     ` Masami Hiramatsu
2020-03-02  1:10                               ` Joel Fernandes
2020-03-02  2:18                                 ` Andy Lutomirski
2020-03-02  2:36                                   ` Joel Fernandes
2020-03-02  5:40                                     ` Andy Lutomirski
2020-03-02  8:10                               ` Thomas Gleixner
2020-03-01 18:23                         ` Steven Rostedt
2020-03-01 18:20                       ` Steven Rostedt
2020-02-27 23:11   ` Frederic Weisbecker
2020-02-28  9:00   ` Alexandre Chartre
2020-02-25 22:08 ` Thomas Gleixner [this message]
2020-02-26  5:45   ` [patch 5/8] x86/entry/common: Provide trace/kprobe safe exit to user space functions Andy Lutomirski
2020-02-26  8:15     ` Peter Zijlstra
2020-02-27 15:43   ` Alexandre Chartre
2020-02-27 15:53     ` Thomas Gleixner
2020-02-25 22:08 ` [patch 6/8] x86/entry: Move irq tracing to syscall_slow_exit_work Thomas Gleixner
2020-02-26  5:47   ` Andy Lutomirski
2020-02-27 16:12   ` Alexandre Chartre
2020-02-25 22:08 ` [patch 7/8] x86/entry: Move irq tracing to prepare_exit_to_user_mode() Thomas Gleixner
2020-02-26  5:50   ` Andy Lutomirski
2020-02-26 19:53     ` Thomas Gleixner
2020-02-26 20:07       ` Andy Lutomirski
2020-02-25 22:08 ` [patch 8/8] x86/entry: Move irqflags tracing to do_int80_syscall_32() Thomas Gleixner
2020-02-27 16:46   ` Alexandre Chartre
2020-02-28 13:49     ` Thomas Gleixner

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