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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] [LINUX] Support creating ELF note segments in the kernel ELF image.
# HG changeset patch
# User Ian Campbell <ian.campbell@xxxxxxxxxxxxx>
# Node ID a4550b7488400c44a9f27c92115c8e364493837a
# Parent cd4e7ace4e58d9e35c08ccaa4677c6b6d0cf137b
[LINUX] Support creating ELF note segments in the kernel ELF image.
i386 version is taken from 2.6.18-rc4-mm1 and x86_64 version has been
submitted for inclusion.
Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxxxxx>
---
linux-2.6-xen-sparse/arch/i386/kernel/vmlinux.lds.S
| 12 +
patches/linux-2.6.16.13/series
| 2
patches/linux-2.6.16.13/x86-put-note-sections-into-a-pt_note-segment-in-vmlinux.patch
| 70 ++++++++++
patches/linux-2.6.16.13/x86_64-put-note-sections-into-a-pt_note-segment-in-vmlinux.patch
| 30 ++++
4 files changed, 112 insertions(+), 2 deletions(-)
diff -r cd4e7ace4e58 -r a4550b748840
linux-2.6-xen-sparse/arch/i386/kernel/vmlinux.lds.S
--- a/linux-2.6-xen-sparse/arch/i386/kernel/vmlinux.lds.S Tue Aug 22
11:34:46 2006 +0100
+++ b/linux-2.6-xen-sparse/arch/i386/kernel/vmlinux.lds.S Tue Aug 22
12:20:43 2006 +0100
@@ -12,6 +12,12 @@ OUTPUT_ARCH(i386)
OUTPUT_ARCH(i386)
ENTRY(phys_startup_32)
jiffies = jiffies_64;
+
+PHDRS {
+ text PT_LOAD FLAGS(5); /* R_E */
+ data PT_LOAD FLAGS(7); /* RWE */
+ note PT_NOTE FLAGS(4); /* R__ */
+}
SECTIONS
{
. = __KERNEL_START;
@@ -25,7 +31,7 @@ SECTIONS
KPROBES_TEXT
*(.fixup)
*(.gnu.warning)
- } = 0x9090
+ } :text = 0x9090
_etext = .; /* End of text section */
@@ -47,7 +53,7 @@ SECTIONS
.data : AT(ADDR(.data) - LOAD_OFFSET) { /* Data */
*(.data)
CONSTRUCTORS
- }
+ } :data
. = ALIGN(4096);
__nosave_begin = .;
@@ -154,4 +160,6 @@ SECTIONS
STABS_DEBUG
DWARF_DEBUG
+
+ NOTES
}
diff -r cd4e7ace4e58 -r a4550b748840 patches/linux-2.6.16.13/series
--- a/patches/linux-2.6.16.13/series Tue Aug 22 11:34:46 2006 +0100
+++ b/patches/linux-2.6.16.13/series Tue Aug 22 12:20:43 2006 +0100
@@ -18,3 +18,5 @@ x86-increase-interrupt-vector-range.patc
x86-increase-interrupt-vector-range.patch
xen-hotplug.patch
xenoprof-generic.patch
+x86-put-note-sections-into-a-pt_note-segment-in-vmlinux.patch
+x86_64-put-note-sections-into-a-pt_note-segment-in-vmlinux.patch
diff -r cd4e7ace4e58 -r a4550b748840
patches/linux-2.6.16.13/x86-put-note-sections-into-a-pt_note-segment-in-vmlinux.patch
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++
b/patches/linux-2.6.16.13/x86-put-note-sections-into-a-pt_note-segment-in-vmlinux.patch
Tue Aug 22 12:20:43 2006 +0100
@@ -0,0 +1,174 @@
+Taken from 2.6.18-rc4-mm1.
+
+From: Jeremy Fitzhardinge <jeremy@xxxxxxxxxxxxx>
+
+This patch will pack any .note.* section into a PT_NOTE segment in the output
+file.
+
+To do this, we tell ld that we need a PT_NOTE segment. This requires us to
+start explicitly mapping sections to segments, so we also need to explicitly
+create PT_LOAD segments for text and data, and map the sections to them
+appropriately. Fortunately, each section will default to its previous
+section's segment, so it doesn't take many changes to vmlinux.lds.S.
+
+This only changes i386 for now, but I presume the corresponding changes for
+other architectures will be as simple.
+
+This change also adds <linux/elfnote.h>, which defines C and Assembler macros
+for actually creating ELF notes.
+
+Signed-off-by: Jeremy Fitzhardinge <jeremy@xxxxxxxxxxxxx>
+Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
+Cc: Hollis Blanchard <hollisb@xxxxxxxxxx>
+Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
+---
+
+ arch/i386/kernel/vmlinux.lds.S | 12 +++
+ include/asm-generic/vmlinux.lds.h | 3
+ include/linux/elfnote.h | 88 ++++++++++++++++++++++++++++
+ 3 files changed, 101 insertions(+), 2 deletions(-)
+
+diff -puN
arch/i386/kernel/vmlinux.lds.S~x86-put-note-sections-into-a-pt_note-segment-in-vmlinux
arch/i386/kernel/vmlinux.lds.S
+---
a/arch/i386/kernel/vmlinux.lds.S~x86-put-note-sections-into-a-pt_note-segment-in-vmlinux
++++ a/arch/i386/kernel/vmlinux.lds.S
+@@ -13,6 +13,12 @@ OUTPUT_FORMAT("elf32-i386", "elf32-i386"
+ OUTPUT_ARCH(i386)
+ ENTRY(phys_startup_32)
+ jiffies = jiffies_64;
++
++PHDRS {
++ text PT_LOAD FLAGS(5); /* R_E */
++ data PT_LOAD FLAGS(7); /* RWE */
++ note PT_NOTE FLAGS(4); /* R__ */
++}
+ SECTIONS
+ {
+ . = __KERNEL_START;
+@@ -26,7 +32,7 @@ SECTIONS
+ KPROBES_TEXT
+ *(.fixup)
+ *(.gnu.warning)
+- } = 0x9090
++ } :text = 0x9090
+
+ _etext = .; /* End of text section */
+
+@@ -50,7 +56,7 @@ SECTIONS
+ .data : AT(ADDR(.data) - LOAD_OFFSET) { /* Data */
+ *(.data)
+ CONSTRUCTORS
+- }
++ } :data
+
+ . = ALIGN(4096);
+ __nosave_begin = .;
+@@ -186,4 +192,6 @@ SECTIONS
+ STABS_DEBUG
+
+ DWARF_DEBUG
++
++ NOTES
+ }
+diff -puN
include/asm-generic/vmlinux.lds.h~x86-put-note-sections-into-a-pt_note-segment-in-vmlinux
include/asm-generic/vmlinux.lds.h
+---
a/include/asm-generic/vmlinux.lds.h~x86-put-note-sections-into-a-pt_note-segment-in-vmlinux
++++ a/include/asm-generic/vmlinux.lds.h
+@@ -194,3 +194,6 @@
+ .stab.index 0 : { *(.stab.index) } \
+ .stab.indexstr 0 : { *(.stab.indexstr) } \
+ .comment 0 : { *(.comment) }
++
++#define NOTES \
++ .notes : { *(.note.*) } :note
+diff -puN /dev/null include/linux/elfnote.h
+--- /dev/null
++++ a/include/linux/elfnote.h
+@@ -0,0 +1,88 @@
++#ifndef _LINUX_ELFNOTE_H
++#define _LINUX_ELFNOTE_H
++/*
++ * Helper macros to generate ELF Note structures, which are put into a
++ * PT_NOTE segment of the final vmlinux image. These are useful for
++ * including name-value pairs of metadata into the kernel binary (or
++ * modules?) for use by external programs.
++ *
++ * Each note has three parts: a name, a type and a desc. The name is
++ * intended to distinguish the note's originator, so it would be a
++ * company, project, subsystem, etc; it must be in a suitable form for
++ * use in a section name. The type is an integer which is used to tag
++ * the data, and is considered to be within the "name" namespace (so
++ * "FooCo"'s type 42 is distinct from "BarProj"'s type 42). The
++ * "desc" field is the actual data. There are no constraints on the
++ * desc field's contents, though typically they're fairly small.
++ *
++ * All notes from a given NAME are put into a section named
++ * .note.NAME. When the kernel image is finally linked, all the notes
++ * are packed into a single .notes section, which is mapped into the
++ * PT_NOTE segment. Because notes for a given name are grouped into
++ * the same section, they'll all be adjacent the output file.
++ *
++ * This file defines macros for both C and assembler use. Their
++ * syntax is slightly different, but they're semantically similar.
++ *
++ * See the ELF specification for more detail about ELF notes.
++ */
++
++#ifdef __ASSEMBLER__
++/*
++ * Generate a structure with the same shape as Elf{32,64}_Nhdr (which
++ * turn out to be the same size and shape), followed by the name and
++ * desc data with appropriate padding. The 'desc' argument includes
++ * the assembler pseudo op defining the type of the data: .asciz
++ * "hello, world"
++ */
++.macro ELFNOTE name type desc:vararg
++.pushsection ".note.\name"
++ .align 4
++ .long 2f - 1f /* namesz */
++ .long 4f - 3f /* descsz */
++ .long \type
++1:.asciz "\name"
++2:.align 4
++3:\desc
++4:.align 4
++.popsection
++.endm
++#else /* !__ASSEMBLER__ */
++#include <linux/elf.h>
++/*
++ * Use an anonymous structure which matches the shape of
++ * Elf{32,64}_Nhdr, but includes the name and desc data. The size and
++ * type of name and desc depend on the macro arguments. "name" must
++ * be a literal string, and "desc" must be passed by value. You may
++ * only define one note per line, since __LINE__ is used to generate
++ * unique symbols.
++ */
++#define _ELFNOTE_PASTE(a,b) a##b
++#define _ELFNOTE(size, name, unique, type, desc) \
++ static const struct { \
++ struct elf##size##_note _nhdr; \
++ unsigned char _name[sizeof(name)] \
++ __attribute__((aligned(sizeof(Elf##size##_Word)))); \
++ typeof(desc) _desc \
++
__attribute__((aligned(sizeof(Elf##size##_Word)))); \
++ } _ELFNOTE_PASTE(_note_, unique) \
++ __attribute_used__ \
++ __attribute__((section(".note." name), \
++ aligned(sizeof(Elf##size##_Word)), \
++ unused)) = { \
++ { \
++ sizeof(name), \
++ sizeof(desc), \
++ type, \
++ }, \
++ name, \
++ desc \
++ }
++#define ELFNOTE(size, name, type, desc) \
++ _ELFNOTE(size, name, __LINE__, type, desc)
++
++#define ELFNOTE32(name, type, desc) ELFNOTE(32, name, type, desc)
++#define ELFNOTE64(name, type, desc) ELFNOTE(64, name, type, desc)
++#endif /* __ASSEMBLER__ */
++
++#endif /* _LINUX_ELFNOTE_H */
+_
diff -r cd4e7ace4e58 -r a4550b748840
patches/linux-2.6.16.13/x86_64-put-note-sections-into-a-pt_note-segment-in-vmlinux.patch
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++
b/patches/linux-2.6.16.13/x86_64-put-note-sections-into-a-pt_note-segment-in-vmlinux.patch
Tue Aug 22 12:20:43 2006 +0100
@@ -0,0 +1,40 @@
+diff -urN ref-linux-2.6.16.13/arch/x86_64/kernel/vmlinux.lds.S
x86-64_elfnotes/arch/x86_64/kernel/vmlinux.lds.S
+--- ref-linux-2.6.16.13/arch/x86_64/kernel/vmlinux.lds.S 2006-05-02
22:38:44.000000000 +0100
++++ x86-64_elfnotes/arch/x86_64/kernel/vmlinux.lds.S 2006-08-22
11:39:14.000000000 +0100
+@@ -14,6 +14,11 @@
+ OUTPUT_ARCH(i386:x86-64)
+ ENTRY(phys_startup_64)
+ jiffies_64 = jiffies;
++PHDRS {
++ text PT_LOAD FLAGS(5); /* R_E */
++ data PT_LOAD FLAGS(7); /* RWE */
++ note PT_NOTE FLAGS(4); /* R__ */
++}
+ SECTIONS
+ {
+ . = __START_KERNEL;
+@@ -26,7 +31,7 @@
+ KPROBES_TEXT
+ *(.fixup)
+ *(.gnu.warning)
+- } = 0x9090
++ } :text = 0x9090
+ /* out-of-line lock text */
+ .text.lock : AT(ADDR(.text.lock) - LOAD_OFFSET) { *(.text.lock) }
+
+@@ -43,7 +48,7 @@
+ .data : AT(ADDR(.data) - LOAD_OFFSET) {
+ *(.data)
+ CONSTRUCTORS
+- }
++ } :data
+
+ _edata = .; /* End of data section */
+
+@@ -201,4 +206,6 @@
+ STABS_DEBUG
+
+ DWARF_DEBUG
++
++ NOTES
+ }
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