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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 13/16] x86/entry: Move irqflags and context tracking to C for simple idtentries
Date: Tue, 25 Feb 2020 23:33:34 +0100	[thread overview]
Message-ID: <20200225224145.444611199@linutronix.de> (raw)
In-Reply-To: 20200225223321.231477305@linutronix.de

Now that everything is converted to the new IDTENTRY mechansim, move the
irq tracing and the invocation of enter_to_user_mode() to C code, i.e. into
the idtentry_enter() inline which is invoked through the IDTENTRY magic.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/entry/entry_32.S       |    1 -
 arch/x86/entry/entry_64.S       |    9 ---------
 arch/x86/include/asm/idtentry.h |   19 ++++++++++++++++++-
 3 files changed, 18 insertions(+), 11 deletions(-)

--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -1452,7 +1452,6 @@ SYM_CODE_START_LOCAL_NOALIGN(common_exce
 	movl	PT_ORIG_EAX(%esp), %edx		# get the error code
 	movl	$-1, PT_ORIG_EAX(%esp)		# no syscall to restart
 
-	TRACE_IRQS_OFF
 	movl	%esp, %eax			# pt_regs pointer
 	CALL_NOSPEC %edi
 	jmp	ret_from_exception
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -511,15 +511,6 @@ SYM_CODE_END(spurious_entries_start)
 		GET_CR2_INTO(%r12);
 	.endif
 
-	TRACE_IRQS_OFF
-
-#ifdef CONFIG_CONTEXT_TRACKING
-	testb	$3, CS(%rsp)
-	jz	.Lfrom_kernel_no_ctxt_tracking_\@
-	CALL_enter_from_user_mode
-.Lfrom_kernel_no_ctxt_tracking_\@:
-#endif
-
 	movq	%rsp, %rdi			/* pt_regs pointer into 1st argument*/
 
 	.if \has_error_code == 1
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -7,14 +7,31 @@
 
 #ifndef __ASSEMBLY__
 
+#ifdef CONFIG_CONTEXT_TRACKING
+static __always_inline void enter_from_user_context(void)
+{
+	CT_WARN_ON(ct_state() != CONTEXT_USER);
+	user_exit_irqoff();
+}
+#else
+static __always_inline void enter_from_user_context(void) { }
+#endif
+
 /**
  * idtentry_enter - Handle state tracking on idtentry
  * @regs:	Pointer to pt_regs of interrupted context
  *
- * Place holder for now.
+ * Invokes:
+ *  - The hardirq tracer to keep the state consistent as low level ASM
+ *    entry disabled interrupts.
+ *
+ *  - Context tracking if the exception hit user mode
  */
 static __always_inline void idtentry_enter(struct pt_regs *regs)
 {
+	trace_hardirqs_off();
+	if (user_mode(regs))
+		enter_from_user_context();
 }
 
 /**


  parent reply	other threads:[~2020-02-25 23:28 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-25 22:33 [patch 00/16] x86/entry: Consolidation - Part IV Thomas Gleixner
2020-02-25 22:33 ` [patch 01/16] x86/entry: Provide IDTENTRY_IST Thomas Gleixner
2020-02-25 22:33 ` [patch 02/16] x86/entry: Convert Machine Check to IDTENTRY_IST Thomas Gleixner
2020-02-25 22:33 ` [patch 03/16] x86/idtentry: Provide IDTENTRY_XEN for XEN/PV Thomas Gleixner
2020-02-25 22:33 ` [patch 04/16] x86/entry: Convert NMI to IDTENTRY_NMI Thomas Gleixner
2020-02-25 22:33 ` [patch 05/16] x86/entry: Convert Debug exception to IDTENTRY_DB Thomas Gleixner
2020-02-25 22:33 ` [patch 06/16] x86/entry/64: Remove error code clearing from #DB and #MCE ASM stub Thomas Gleixner
2020-02-25 22:33 ` [patch 07/16] x86/entry: Provide IDTRENTRY_NOIST variants for #DB and #MC Thomas Gleixner
2020-02-25 22:33 ` [patch 08/16] x86/entry: Implement user mode C entry points for #DB and #MCE Thomas Gleixner
2020-02-25 22:33 ` [patch 09/16] x86/entry: Provide IDTENTRY_DF Thomas Gleixner
2020-02-25 22:33 ` [patch 10/16] x86/entry: Convert double fault exception to IDTENTRY_DF Thomas Gleixner
2020-02-25 22:33 ` [patch 11/16] x86/entry: Switch XEN/PV hypercall entry to IDTENTRY Thomas Gleixner
2020-02-25 22:33 ` [patch 12/16] x86/entry/64: Simplify idtentry_body Thomas Gleixner
2020-02-25 22:33 ` Thomas Gleixner [this message]
2020-02-26  8:05   ` [patch 13/16] x86/entry: Move irqflags and context tracking to C for simple idtentries Peter Zijlstra
2020-02-26  9:20     ` Peter Zijlstra
2020-02-26 15:11       ` Andy Lutomirski
2020-02-26 16:28         ` Peter Zijlstra
2020-02-26 19:15           ` Andy Lutomirski
2020-02-26 20:25             ` Thomas Gleixner
2020-02-26 17:05     ` Frederic Weisbecker
2020-02-26 17:09       ` Andy Lutomirski
2020-02-26 17:17         ` Frederic Weisbecker
2020-02-25 22:33 ` [patch 14/16] x86/entry: Provide IDTENTRY_CR2 Thomas Gleixner
2020-02-25 22:33 ` [patch 15/16] x86/entry: Switch page fault exceptions to idtentry_simple Thomas Gleixner
2020-03-05 21:51   ` Andy Lutomirski
2020-03-05 23:02     ` Thomas Gleixner
2020-02-25 22:33 ` [patch 16/16] x86/entry: Disable interrupts in IDTENTRY Thomas Gleixner
2020-02-26  9:23   ` Peter Zijlstra
2020-02-26 20:21     ` Thomas Gleixner
2020-02-27  8:41       ` Peter Zijlstra

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