Patchwork [3.5.y.z,extended,stable] Patch "ARM: use linker magic for vectors and vector stubs" has been added to staging queue

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Submitter Luis Henriques
Date Aug. 4, 2013, 9:49 a.m.
Message ID <1375609771-11689-1-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/264503/
State New
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Comments

Luis Henriques - Aug. 4, 2013, 9:49 a.m.
This is a note to let you know that I have just added a patch titled

    ARM: use linker magic for vectors and vector stubs

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

From e96475cfa2a7595e252b06300543b22140811faa Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Thu, 4 Jul 2013 12:03:31 +0100
Subject: [PATCH] ARM: use linker magic for vectors and vector stubs

commit b9b32bf70f2fb710b07c94e13afbc729afe221da upstream.

Use linker magic to create the vectors and vector stubs: we can tell the
linker to place them at an appropriate VMA, but keep the LMA within the
kernel.  This gets rid of some unnecessary symbol manipulation, and
have the linker calculate the relocations appropriately.

Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 arch/arm/kernel/entry-armv.S  | 28 ++++++++++------------------
 arch/arm/kernel/vmlinux.lds.S | 17 +++++++++++++++++
 2 files changed, 27 insertions(+), 18 deletions(-)

--
1.8.3.2

Patch

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index a4af8e8..c19779f 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -1035,7 +1035,7 @@  ENDPROC(vector_\name)
 1:
 	.endm

-	.globl	__stubs_start
+	.section .stubs, "ax", %progbits
 __stubs_start:
 	@ This must be the first word
 	.word	vector_swi
@@ -1162,24 +1162,16 @@  vector_addrexcptn:
 vector_fiq:
 	subs	pc, lr, #4

-	.globl	__stubs_end
-__stubs_end:
-
-	.equ	stubs_offset, __vectors_start + 0x1000 - __stubs_start
-
-	.globl	__vectors_start
+	.section .vectors, "ax", %progbits
 __vectors_start:
-	W(b)	vector_rst + stubs_offset
-	W(b)	vector_und + stubs_offset
-	W(ldr)	pc, .LCvswi + stubs_offset
-	W(b)	vector_pabt + stubs_offset
-	W(b)	vector_dabt + stubs_offset
-	W(b)	vector_addrexcptn + stubs_offset
-	W(b)	vector_irq + stubs_offset
-	W(b)	vector_fiq + stubs_offset
-
-	.globl	__vectors_end
-__vectors_end:
+	W(b)	vector_rst
+	W(b)	vector_und
+	W(ldr)	pc, __vectors_start + 0x1000
+	W(b)	vector_pabt
+	W(b)	vector_dabt
+	W(b)	vector_addrexcptn
+	W(b)	vector_irq
+	W(b)	vector_fiq

 	.data

diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 36ff15b..2f8f92e 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -137,6 +137,23 @@  SECTIONS
 	. = ALIGN(PAGE_SIZE);
 	__init_begin = .;
 #endif
+	/*
+	 * The vectors and stubs are relocatable code, and the
+	 * only thing that matters is their relative offsets
+	 */
+	__vectors_start = .;
+	.vectors 0 : AT(__vectors_start) {
+		*(.vectors)
+	}
+	. = __vectors_start + SIZEOF(.vectors);
+	__vectors_end = .;
+
+	__stubs_start = .;
+	.stubs 0x1000 : AT(__stubs_start) {
+		*(.stubs)
+	}
+	. = __stubs_start + SIZEOF(.stubs);
+	__stubs_end = .;

 	INIT_TEXT_SECTION(8)
 	.exit.text : {