From: "tip-bot2 for Thomas Gleixner" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
Alexandre Chartre <alexandre.chartre@oracle.com>,
Peter Zijlstra <peterz@infradead.org>,
Andy Lutomirski <luto@kernel.org>, x86 <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: [tip: x86/entry] x86/entry/common: Provide idtentry_enter/exit()
Date: Tue, 19 May 2020 19:58:35 -0000 [thread overview]
Message-ID: <158991831562.17951.6216563865898704227.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20200505134904.457578656@linutronix.de>
The following commit has been merged into the x86/entry branch of tip:
Commit-ID: eadb831607477ba774b3314bdc956331b41817d6
Gitweb: https://git.kernel.org/tip/eadb831607477ba774b3314bdc956331b41817d6
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Thu, 26 Mar 2020 16:28:52 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Tue, 19 May 2020 16:03:57 +02:00
x86/entry/common: Provide idtentry_enter/exit()
Provide functions which handle the low level entry and exit similar to
enter/exit from user mode.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200505134904.457578656@linutronix.de
---
arch/x86/entry/common.c | 99 +++++++++++++++++++++++++++++++-
arch/x86/include/asm/idtentry.h | 3 +-
2 files changed, 102 insertions(+)
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index e4f9f5f..9ebe334 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -510,3 +510,102 @@ SYSCALL_DEFINE0(ni_syscall)
{
return -ENOSYS;
}
+
+/**
+ * idtentry_enter - Handle state tracking on idtentry
+ * @regs: Pointer to pt_regs of interrupted context
+ *
+ * Invokes:
+ * - lockdep irqflag state tracking as low level ASM entry disabled
+ * interrupts.
+ *
+ * - Context tracking if the exception hit user mode.
+ *
+ * - RCU notification if the exception hit kernel mode.
+ *
+ * - The hardirq tracer to keep the state consistent as low level ASM
+ * entry disabled interrupts.
+ */
+void noinstr idtentry_enter(struct pt_regs *regs)
+{
+ if (user_mode(regs)) {
+ enter_from_user_mode();
+ } else {
+ lockdep_hardirqs_off(CALLER_ADDR0);
+ rcu_irq_enter();
+ instrumentation_begin();
+ trace_hardirqs_off_prepare();
+ instrumentation_end();
+ }
+}
+
+/**
+ * idtentry_exit - Common code to handle return from exceptions
+ * @regs: Pointer to pt_regs (exception entry regs)
+ *
+ * Depending on the return target (kernel/user) this runs the necessary
+ * preemption and work checks if possible and required and returns to
+ * the caller with interrupts disabled and no further work pending.
+ *
+ * This is the last action before returning to the low level ASM code which
+ * just needs to return to the appropriate context.
+ *
+ * Invoked by all exception/interrupt IDTENTRY handlers which are not
+ * returning through the paranoid exit path (all except NMI, #DF and the IST
+ * variants of #MC and #DB) and are therefore on the thread stack.
+ */
+void noinstr idtentry_exit(struct pt_regs *regs)
+{
+ lockdep_assert_irqs_disabled();
+
+ /* Check whether this returns to user mode */
+ if (user_mode(regs)) {
+ prepare_exit_to_usermode(regs);
+ } else if (regs->flags & X86_EFLAGS_IF) {
+ /* Check kernel preemption, if enabled */
+ if (IS_ENABLED(CONFIG_PREEMPTION)) {
+ /*
+ * This needs to be done very carefully.
+ * idtentry_enter() invoked rcu_irq_enter(). This
+ * needs to be undone before scheduling.
+ *
+ * Preemption is disabled inside of RCU idle
+ * sections. When the task returns from
+ * preempt_schedule_irq(), RCU is still watching.
+ *
+ * rcu_irq_exit_preempt() has additional state
+ * checking if CONFIG_PROVE_RCU=y
+ */
+ if (!preempt_count()) {
+ if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
+ WARN_ON_ONCE(!on_thread_stack());
+ instrumentation_begin();
+ rcu_irq_exit_preempt();
+ if (need_resched())
+ preempt_schedule_irq();
+ /* Covers both tracing and lockdep */
+ trace_hardirqs_on();
+ instrumentation_end();
+ return;
+ }
+ }
+ /*
+ * If preemption is disabled then this needs to be done
+ * carefully with respect to RCU. The exception might come
+ * from a RCU idle section in the idle task due to the fact
+ * that safe_halt() enables interrupts. So this needs the
+ * same ordering of lockdep/tracing and RCU as the return
+ * to user mode path.
+ */
+ instrumentation_begin();
+ /* Tell the tracer that IRET will enable interrupts */
+ trace_hardirqs_on_prepare();
+ lockdep_hardirqs_on_prepare(CALLER_ADDR0);
+ instrumentation_end();
+ rcu_irq_exit();
+ lockdep_hardirqs_on(CALLER_ADDR0);
+ } else {
+ /* IRQ flags state is correct already. Just tell RCU */
+ rcu_irq_exit();
+ }
+}
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index bbd81e2..2adfd80 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -7,6 +7,9 @@
#ifndef __ASSEMBLY__
+void idtentry_enter(struct pt_regs *regs);
+void idtentry_exit(struct pt_regs *regs);
+
/**
* DECLARE_IDTENTRY - Declare functions for simple IDT entry points
* No error code pushed by hardware
next prev parent reply other threads:[~2020-05-19 19:59 UTC|newest]
Thread overview: 129+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 13:43 [patch V4 part 3 00/29] x86/entry: Entry/exception code rework, simple exceptions Thomas Gleixner
2020-05-05 13:43 ` [patch V4 part 3 01/29] x86/traps: Mark fixup_bad_iret() noinstr Thomas Gleixner
2020-05-09 0:39 ` Andy Lutomirski
2020-05-13 1:51 ` Steven Rostedt
2020-05-14 0:41 ` Mathieu Desnoyers
2020-05-14 1:35 ` Andy Lutomirski
2020-05-11 12:28 ` Masami Hiramatsu
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:43 ` [patch V4 part 3 02/29] x86/traps: Mark sync_regs() noinstr Thomas Gleixner
2020-05-09 0:39 ` Andy Lutomirski
2020-05-11 12:08 ` Masami Hiramatsu
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:43 ` [patch V4 part 3 03/29] x86/entry: Disable interrupts for native_load_gs_index() in C code Thomas Gleixner
2020-05-09 0:40 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:43 ` [patch V4 part 3 04/29] x86/traps: Make interrupt enable/disable symmetric " Thomas Gleixner
2020-05-07 15:25 ` Alexandre Chartre
2020-05-07 17:14 ` Thomas Gleixner
2020-05-09 0:44 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:43 ` [patch V4 part 3 05/29] x86/traps: Split trap numbers out in a seperate header Thomas Gleixner
2020-05-07 15:34 ` Alexandre Chartre
2020-05-19 19:58 ` [tip: x86/entry] x86/traps: Split trap numbers out in a separate header tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 06/29] x86/entry/64: Reorder idtentries Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 07/29] x86/entry: Distangle idtentry Thomas Gleixner
2020-05-10 20:31 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 08/29] x86/entry/64: Provide sane error entry/exit Thomas Gleixner
2020-05-10 21:02 ` Andy Lutomirski
2020-05-13 2:10 ` Steven Rostedt
2020-05-13 6:35 ` Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 09/29] x86/entry/32: Provide macro to emit IDT entry stubs Thomas Gleixner
2020-05-11 0:55 ` Andy Lutomirski
2020-05-14 1:44 ` Mathieu Desnoyers
2020-05-14 4:31 ` Andy Lutomirski
2020-05-14 13:38 ` Mathieu Desnoyers
2020-05-14 14:08 ` Thomas Gleixner
2020-05-14 14:43 ` Mathieu Desnoyers
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 10/29] x86/idtentry: Provide macros to define/declare IDT entry points Thomas Gleixner
2020-05-11 0:58 ` Andy Lutomirski
2020-05-11 10:39 ` Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 11/29] rcu: Provide rcu_irq_exit_preempt() Thomas Gleixner
2020-05-05 22:02 ` Paul E. McKenney
2020-05-05 22:05 ` Thomas Gleixner
2020-05-05 22:24 ` Paul E. McKenney
2020-05-14 1:03 ` Mathieu Desnoyers
2020-05-14 2:41 ` Joel Fernandes
2020-05-14 2:46 ` Joel Fernandes
2020-05-14 14:43 ` Thomas Gleixner
2020-05-15 19:00 ` Joel Fernandes
2020-05-19 19:52 ` [tip: core/rcu] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 12/29] x86/entry/common: Provide idtentry_enter/exit() Thomas Gleixner
2020-05-07 16:27 ` Alexandre Chartre
2020-05-11 4:34 ` Andy Lutomirski
2020-05-11 10:59 ` [patch V5 " Thomas Gleixner
2020-05-11 15:31 ` Andy Lutomirski
2020-05-11 18:42 ` Thomas Gleixner
2020-05-12 16:49 ` [patch V6 " Thomas Gleixner
2020-05-14 0:51 ` Andy Lutomirski
2020-05-14 1:08 ` [patch V4 " Mathieu Desnoyers
2020-05-19 19:58 ` tip-bot2 for Thomas Gleixner [this message]
2020-05-05 13:44 ` [patch V4 part 3 13/29] x86/traps: Prepare for using DEFINE_IDTENTRY Thomas Gleixner
2020-05-14 4:37 ` Andy Lutomirski
2020-05-14 12:16 ` Thomas Gleixner
2020-05-14 12:33 ` Peter Zijlstra
2020-05-15 13:42 ` Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 14/29] x86/entry: Convert Divide Error to IDTENTRY Thomas Gleixner
2020-05-14 4:38 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-10-11 15:25 ` Dmitry Vyukov
2020-10-11 17:50 ` Thomas Gleixner
2020-10-12 13:19 ` [tip: x86/urgent] x86/traps: Fix #DE Oops message regression tip-bot2 for Thomas Gleixner
2020-10-12 20:30 ` [tip: x86/entry] x86/entry: Convert Divide Error to IDTENTRY Kees Cook
2020-10-13 10:19 ` Dmitry Vyukov
2020-10-13 17:41 ` [tip: x86/urgent] x86/traps: Fix #DE Oops message regression tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 15/29] x86/entry: Convert Overflow exception to IDTENTRY Thomas Gleixner
2020-05-14 4:39 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 16/29] x86/entry: Convert Bounds " Thomas Gleixner
2020-05-14 4:42 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 17/29] x86/entry: Convert Invalid Opcode " Thomas Gleixner
2020-05-14 4:45 ` Andy Lutomirski
2020-05-14 12:33 ` Thomas Gleixner
2020-05-14 15:00 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 18/29] x86/entry: Convert Device not available " Thomas Gleixner
2020-05-14 4:45 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 19/29] x86/entry: Convert Coprocessor segment overrun " Thomas Gleixner
2020-05-14 4:46 ` Andy Lutomirski
2020-05-05 13:44 ` [patch V4 part 3 20/29] x86/entry: Provide IDTENTRY_ERRORCODE Thomas Gleixner
2020-05-14 4:46 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] x86/idtentry: " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 21/29] x86/entry: Convert Invalid TSS exception to IDTENTRY Thomas Gleixner
2020-05-14 4:48 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 22/29] x86/entry: Convert Segment not present " Thomas Gleixner
2020-05-14 4:47 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 23/29] x86/entry: Convert Stack segment " Thomas Gleixner
2020-05-14 4:49 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 24/29] x86/entry: Convert General protection " Thomas Gleixner
2020-05-14 4:50 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 25/29] x86/entry: Convert Spurious interrupt bug " Thomas Gleixner
2020-05-14 4:47 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 26/29] x86/entry: Convert Coprocessor error " Thomas Gleixner
2020-05-14 4:49 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] x86/entry: Convert Coprocessor segment overrun " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 27/29] x86/entry: Convert Alignment check " Thomas Gleixner
2020-05-14 4:50 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 28/29] x86/entry: Convert SIMD coprocessor error " Thomas Gleixner
2020-05-14 4:56 ` Andy Lutomirski
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:44 ` [patch V4 part 3 29/29] x86/entry/32: Convert IRET exception to IDTENTRY_SW Thomas Gleixner
2020-05-07 16:47 ` Alexandre Chartre
2020-05-14 4:54 ` Andy Lutomirski
2020-05-15 14:11 ` Thomas Gleixner
2020-05-19 19:58 ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
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