[PATCH v15 04/25] x86/asm: Frame pointer macro cleanup

Path	csiph.com!eternal-september.org!feeder.eternal-september.org!aioe.org!bofh.it!news.nic.it!robomod
From	Josh Poimboeuf <jpoimboe@redhat.com>
Newsgroups	linux.kernel
Subject	[PATCH v15 04/25] x86/asm: Frame pointer macro cleanup
Date	Fri, 18 Dec 2015 13:50:01 +0100
Message-ID	<qH2DT-5IP-5@gated-at.bofh.it> (permalink)
References	<qH2DT-5IP-3@gated-at.bofh.it>
X-Original-To	Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org
X-Scanned-By	MIMEDefang 2.68 on 10.5.11.23
Sender	robomod@news.nic.it
List-ID	<linux-kernel.vger.kernel.org>
X-Mailing-List	linux-kernel@vger.kernel.org
Approved	robomod@news.nic.it
Lines	75
Organization	linux.* mail to news gateway
X-Original-Cc	linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, Michal Marek <mmarek@suse.cz>, Peter Zijlstra <peterz@infradead.org>, Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>, Linus Torvalds <torvalds@linux-foundation.org>, Andi Kleen <andi@firstfloor.org>, Pedro Alves <palves@redhat.com>, Namhyung Kim <namhyung@gmail.com>, Bernd Petrovitsch <bernd@petrovitsch.priv.at>, Chris J Arges <chris.j.arges@canonical.com>, Andrew Morton <akpm@linux-foundation.org>, Jiri Slaby <jslaby@suse.cz>, Arnaldo Carvalho de Melo <acme@kernel.org>
X-Original-Date	Fri, 18 Dec 2015 06:39:18 -0600
X-Original-Message-ID	<3f488a8e3bfc8ac7d4d3d350953e664e7182b044.1450442274.git.jpoimboe@redhat.com>
X-Original-References	<cover.1450442274.git.jpoimboe@redhat.com>
X-Original-Sender	linux-kernel-owner@vger.kernel.org
Xref	csiph.com linux.kernel:1294756

Show key headers only | View raw

The asm macros for setting up and restoring the frame pointer aren't
currently being used.  However, they will be needed soon to help asm
functions to comply with stacktool.

Rename FRAME/ENDFRAME to FRAME_BEGIN/FRAME_END for more symmetry.  Also
make the code more readable and improve the comments.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 arch/x86/include/asm/frame.h | 43 +++++++++++++++++++++++++++----------------
 1 file changed, 27 insertions(+), 16 deletions(-)

diff --git a/arch/x86/include/asm/frame.h b/arch/x86/include/asm/frame.h
index 793179c..cec213b 100644
--- a/arch/x86/include/asm/frame.h
+++ b/arch/x86/include/asm/frame.h
@@ -1,23 +1,34 @@
+#ifndef _ASM_X86_FRAME_H
+#define _ASM_X86_FRAME_H
+
 #ifdef __ASSEMBLY__
 
 #include <asm/asm.h>
 
-/* The annotation hides the frame from the unwinder and makes it look
-   like a ordinary ebp save/restore. This avoids some special cases for
-   frame pointer later */
+/*
+ * These are stack frame creation macros.  They should be used by every
+ * callable non-leaf asm function to make kernel stack traces more reliable.
+ */
 #ifdef CONFIG_FRAME_POINTER
-	.macro FRAME
-	__ASM_SIZE(push,)	%__ASM_REG(bp)
-	__ASM_SIZE(mov)		%__ASM_REG(sp), %__ASM_REG(bp)
-	.endm
-	.macro ENDFRAME
-	__ASM_SIZE(pop,)	%__ASM_REG(bp)
-	.endm
-#else
-	.macro FRAME
-	.endm
-	.macro ENDFRAME
-	.endm
-#endif
+
+.macro FRAME_BEGIN
+	push %_ASM_BP
+	_ASM_MOV %_ASM_SP, %_ASM_BP
+.endm
+
+.macro FRAME_END
+	pop %_ASM_BP
+.endm
+
+#define FRAME_OFFSET __ASM_SEL(4, 8)
+
+#else /* !CONFIG_FRAME_POINTER */
+
+#define FRAME_BEGIN
+#define FRAME_END
+#define FRAME_OFFSET 0
+
+#endif /* CONFIG_FRAME_POINTER */
 
 #endif  /*  __ASSEMBLY__  */
+#endif /* _ASM_X86_FRAME_H */
-- 
2.4.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

[PATCH v15 04/25] x86/asm: Frame pointer macro cleanup Josh Poimboeuf <jpoimboe@redhat.com> - 2015-12-18 13:50 +0100

csiph-web