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 02/24] x86/entry/64: Avoid pointless code when CONTEXT_TRACKING=n
Date: Tue, 25 Feb 2020 23:16:08 +0100 [thread overview]
Message-ID: <20200225222648.395059616@linutronix.de> (raw)
In-Reply-To: 20200225221606.511535280@linutronix.de
GAS cannot optimize out the test and conditional jump when context tracking
is disabled and CALL_enter_from_user_mode is an empty macro.
Wrap it in #ifdeffery. Will go away once all this is moved to C.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/entry/entry_64.S | 2 ++
1 file changed, 2 insertions(+)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -884,12 +884,14 @@ apicinterrupt IRQ_WORK_VECTOR irq_work
TRACE_IRQS_OFF
.endif
+#ifdef CONFIG_CONTEXT_TRACKING
.if \paranoid == 0
testb $3, CS(%rsp)
jz .Lfrom_kernel_no_context_tracking_\@
CALL_enter_from_user_mode
.Lfrom_kernel_no_context_tracking_\@:
.endif
+#endif
movq %rsp, %rdi /* pt_regs pointer */
next prev parent reply other threads:[~2020-02-25 23:29 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-25 22:16 [patch 00/24] x86/entry: Consolidation - Part III Thomas Gleixner
2020-02-25 22:16 ` [patch 01/24] x86/traps: Split trap numbers out in a seperate header Thomas Gleixner
2020-02-26 5:52 ` Andy Lutomirski
2020-02-28 9:39 ` Alexandre Chartre
2020-02-25 22:16 ` Thomas Gleixner [this message]
2020-02-26 5:52 ` [patch 02/24] x86/entry/64: Avoid pointless code when CONTEXT_TRACKING=n Andy Lutomirski
2020-02-28 9:40 ` Alexandre Chartre
2020-03-02 22:25 ` Frederic Weisbecker
2020-02-25 22:16 ` [patch 03/24] x86/entry/64: Reorder idtentries Thomas Gleixner
2020-02-26 5:53 ` Andy Lutomirski
2020-02-28 9:40 ` Alexandre Chartre
2020-02-25 22:16 ` [patch 04/24] x86/entry: Distangle idtentry Thomas Gleixner
2020-02-28 10:27 ` Alexandre Chartre
2020-02-25 22:16 ` [patch 05/24] x86/entry/32: Provide macro to emit IDT entry stubs Thomas Gleixner
2020-02-28 10:33 ` Alexandre Chartre
2020-02-25 22:16 ` [patch 06/24] x86/idtentry: Provide macros to define/declare IDT entry points Thomas Gleixner
2020-02-28 10:42 ` Alexandre Chartre
2020-03-04 12:46 ` Thomas Gleixner
2020-02-25 22:16 ` [patch 07/24] x86/traps: Prepare for using DEFINE_IDTENTRY Thomas Gleixner
2020-02-28 14:13 ` Alexandre Chartre
2020-02-28 14:18 ` Thomas Gleixner
2020-02-25 22:16 ` [patch 08/24] x86/entry: Convert Divide Error to IDTENTRY Thomas Gleixner
2020-02-28 14:58 ` Alexandre Chartre
2020-03-04 13:09 ` Thomas Gleixner
2020-02-25 22:16 ` [patch 09/24] x86/entry: Convert Overflow exception " Thomas Gleixner
2020-02-25 22:16 ` [patch 10/24] x86/entry: Convert INT3 " Thomas Gleixner
2020-02-25 22:16 ` [patch 11/24] x86/entry: Convert Bounds " Thomas Gleixner
2020-02-25 22:16 ` [patch 12/24] x86/entry: Convert Invalid Opcode " Thomas Gleixner
2020-02-25 22:16 ` [patch 13/24] x86/entry: Convert Device not available " Thomas Gleixner
2020-02-25 22:16 ` [patch 14/24] x86/entry: Convert Coprocessor segment overrun " Thomas Gleixner
2020-02-25 22:16 ` [patch 15/24] x86/entry: Provide IDTENTRY_ERRORCODE Thomas Gleixner
2020-02-25 22:16 ` [patch 16/24] x86/entry: Convert Invalid TSS exception to IDTENTRY Thomas Gleixner
2020-02-25 22:16 ` [patch 17/24] x86/entry: Convert Segment not present " Thomas Gleixner
2020-02-25 22:16 ` [patch 18/24] x86/entry: Convert Stack segment " Thomas Gleixner
2020-02-25 22:16 ` [patch 19/24] x86/entry: Convert General protection " Thomas Gleixner
2020-02-25 22:16 ` [patch 20/24] x86/entry: Convert Spurious interrupt bug " Thomas Gleixner
2020-02-25 22:16 ` [patch 21/24] x86/entry: Convert Coprocessor error " Thomas Gleixner
2020-02-25 22:16 ` [patch 22/24] x86/entry: Convert Alignment check " Thomas Gleixner
2020-02-25 22:16 ` [patch 23/24] x86/entry: Convert SIMD coprocessor error " Thomas Gleixner
2020-02-25 22:16 ` [patch 24/24] x86/entry/32: Convert IRET exception to IDTENTRY_SW Thomas Gleixner
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