[PATCH 10/29] x86_64-vmlinux-fix-physical-addrs

From: Eric W. Biederman
Date: Wed Jan 19 2005 - 04:03:38 EST



The vmlinux on x86_64 does not report the correct physical address of
the kernel. Instead in the physical address field it currently
reports the virtual address of the kernel.

This is patch is a bug fix that corrects vmlinux to report the
proper physical addresses.

This is potentially a help for crash dump analysis tools.

This definitiely allows bootloaders that load vmlinux as a standard
ELF executable. Bootloaders directly loading vmlinux become of
practical importance when we consider the kexec on panic case.

Signed-off-by: Eric Biederman <ebiederm@xxxxxxxxxxxx>
---

Makefile | 2
kernel/vmlinux.lds.S | 130 ++++++++++++++++++++++++++++++++++-----------------
2 files changed, 88 insertions(+), 44 deletions(-)

diff -uNr linux-2.6.11-rc1-mm1-nokexec-x86-vmlinux-fix-physical-addrs/arch/x86_64/Makefile linux-2.6.11-rc1-mm1-nokexec-x86_64-vmlinux-fix-physical-addrs/arch/x86_64/Makefile
--- linux-2.6.11-rc1-mm1-nokexec-x86-vmlinux-fix-physical-addrs/arch/x86_64/Makefile Fri Jan 14 04:28:33 2005
+++ linux-2.6.11-rc1-mm1-nokexec-x86_64-vmlinux-fix-physical-addrs/arch/x86_64/Makefile Tue Jan 18 22:46:07 2005
@@ -35,7 +35,7 @@

LDFLAGS := -m elf_x86_64
OBJCOPYFLAGS := -O binary -R .note -R .comment -S
-LDFLAGS_vmlinux := -e stext
+LDFLAGS_vmlinux :=

CHECKFLAGS += -D__x86_64__ -m64

diff -uNr linux-2.6.11-rc1-mm1-nokexec-x86-vmlinux-fix-physical-addrs/arch/x86_64/kernel/vmlinux.lds.S linux-2.6.11-rc1-mm1-nokexec-x86_64-vmlinux-fix-physical-addrs/arch/x86_64/kernel/vmlinux.lds.S
--- linux-2.6.11-rc1-mm1-nokexec-x86-vmlinux-fix-physical-addrs/arch/x86_64/kernel/vmlinux.lds.S Fri Jan 7 12:53:50 2005
+++ linux-2.6.11-rc1-mm1-nokexec-x86_64-vmlinux-fix-physical-addrs/arch/x86_64/kernel/vmlinux.lds.S Tue Jan 18 22:46:07 2005
@@ -2,36 +2,41 @@
* Written by Martin Mares <mj@xxxxxxxxxxxxxxxxxxxxxxxx>;
*/

+#define LOAD_OFFSET __START_KERNEL_map
+
#include <asm-generic/vmlinux.lds.h>
+#include <asm/page.h>
#include <linux/config.h>

OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64", "elf64-x86-64")
OUTPUT_ARCH(i386:x86-64)
-ENTRY(_start)
+ENTRY(stext)
jiffies_64 = jiffies;
SECTIONS
{
- . = 0xffffffff80100000;
+ . = __START_KERNEL;
_text = .; /* Text and read-only data */
- .text : {
+ .text : AT(ADDR(.text) - LOAD_OFFSET) {
*(.text)
SCHED_TEXT
LOCK_TEXT
*(.fixup)
*(.gnu.warning)
} = 0x9090
- .text.lock : { *(.text.lock) } /* out-of-line lock text */
+ /* out-of-line lock text */
+ .text.lock : AT(ADDR(.text.lock) - LOAD_OFFSET) { *(.text.lock) }

_etext = .; /* End of text section */

. = ALIGN(16); /* Exception table */
__start___ex_table = .;
- __ex_table : { *(__ex_table) }
+ __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) { *(__ex_table) }
__stop___ex_table = .;

RODATA

- .data : { /* Data */
+ /* Data */
+ .data : AT(ADDR(.data) - LOAD_OFFSET) {
*(.data)
CONSTRUCTORS
}
@@ -39,62 +44,95 @@
_edata = .; /* End of data section */

__bss_start = .; /* BSS */
- .bss : {
+ .bss : AT(ADDR(.bss) - LOAD_OFFSET) {
*(.bss.page_aligned)
*(.bss)
}
__bss_end = .;

+ . = ALIGN(PAGE_SIZE);
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
- .data.cacheline_aligned : { *(.data.cacheline_aligned) }
+ .data.cacheline_aligned : AT(ADDR(.data.cacheline_aligned) - LOAD_OFFSET) {
+ *(.data.cacheline_aligned)
+ }

-#define AFTER(x) BINALIGN(LOADADDR(x) + SIZEOF(x), 16)
-#define BINALIGN(x,y) (((x) + (y) - 1) & ~((y) - 1))
-#define CACHE_ALIGN(x) BINALIGN(x, CONFIG_X86_L1_CACHE_BYTES)
+#define VSYSCALL_ADDR (-10*1024*1024)
+#define VSYSCALL_PHYS_ADDR ((LOADADDR(.data.cacheline_aligned) + SIZEOF(.data.cacheline_aligned) + 4095) & ~(4095))
+#define VSYSCALL_VIRT_ADDR ((ADDR(.data.cacheline_aligned) + SIZEOF(.data.cacheline_aligned) + 4095) & ~(4095))
+
+#define VLOAD_OFFSET (VSYSCALL_ADDR - VSYSCALL_PHYS_ADDR)
+#define VLOAD(x) (ADDR(x) - VLOAD_OFFSET)
+
+#define VVIRT_OFFSET (VSYSCALL_ADDR - VSYSCALL_VIRT_ADDR)
+#define VVIRT(x) (ADDR(x) - VVIRT_OFFSET)
+
+ . = VSYSCALL_ADDR;
+ .vsyscall_0 : AT(VSYSCALL_PHYS_ADDR) { *(.vsyscall_0) }
+ __vsyscall_0 = VSYSCALL_VIRT_ADDR;

- .vsyscall_0 -10*1024*1024: AT ((LOADADDR(.data.cacheline_aligned) + SIZEOF(.data.cacheline_aligned) + 4095) & ~(4095)) { *(.vsyscall_0) }
- __vsyscall_0 = LOADADDR(.vsyscall_0);
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
- .xtime_lock : AT CACHE_ALIGN(AFTER(.vsyscall_0)) { *(.xtime_lock) }
- xtime_lock = LOADADDR(.xtime_lock);
- .vxtime : AT AFTER(.xtime_lock) { *(.vxtime) }
- vxtime = LOADADDR(.vxtime);
- .wall_jiffies : AT AFTER(.vxtime) { *(.wall_jiffies) }
- wall_jiffies = LOADADDR(.wall_jiffies);
- .sys_tz : AT AFTER(.wall_jiffies) { *(.sys_tz) }
- sys_tz = LOADADDR(.sys_tz);
- .sysctl_vsyscall : AT AFTER(.sys_tz) { *(.sysctl_vsyscall) }
- sysctl_vsyscall = LOADADDR(.sysctl_vsyscall);
- .xtime : AT AFTER(.sysctl_vsyscall) { *(.xtime) }
- xtime = LOADADDR(.xtime);
+ .xtime_lock : AT(VLOAD(.xtime_lock)) { *(.xtime_lock) }
+ xtime_lock = VVIRT(.xtime_lock);
+
+ .vxtime : AT(VLOAD(.vxtime)) { *(.vxtime) }
+ vxtime = VVIRT(.vxtime);
+
+ .wall_jiffies : AT(VLOAD(.wall_jiffies)) { *(.wall_jiffies) }
+ wall_jiffies = VVIRT(.wall_jiffies);
+
+ .sys_tz : AT(VLOAD(.sys_tz)) { *(.sys_tz) }
+ sys_tz = VVIRT(.sys_tz);
+
+ .sysctl_vsyscall : AT(VLOAD(.sysctl_vsyscall)) { *(.sysctl_vsyscall) }
+ sysctl_vsyscall = VVIRT(.sysctl_vsyscall);
+
+ .xtime : AT(VLOAD(.xtime)) { *(.xtime) }
+ xtime = VVIRT(.xtime);
+
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
- .jiffies : AT CACHE_ALIGN(AFTER(.xtime)) { *(.jiffies) }
- jiffies = LOADADDR(.jiffies);
- .vsyscall_1 ADDR(.vsyscall_0) + 1024: AT (LOADADDR(.vsyscall_0) + 1024) { *(.vsyscall_1) }
- . = LOADADDR(.vsyscall_0) + 4096;
+ .jiffies : AT(VLOAD(.jiffies)) { *(.jiffies) }
+ jiffies = VVIRT(.jiffies);
+
+ .vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1)) { *(.vsyscall_1) }
+ .vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2)) { *(.vsyscall_2) }
+ .vsyscall_3 ADDR(.vsyscall_0) + 3072: AT(VLOAD(.vsyscall_3)) { *(.vsyscall_3) }
+
+ . = VSYSCALL_VIRT_ADDR + 4096;
+
+#undef VSYSCALL_ADDR
+#undef VSYSCALL_PHYS_ADDR
+#undef VSYSCALL_VIRT_ADDR
+#undef VLOAD_OFFSET
+#undef VLOAD
+#undef VVIRT_OFFSET
+#undef VVIRT

. = ALIGN(8192); /* init_task */
- .data.init_task : { *(.data.init_task) }
+ .data.init_task : AT(ADDR(.data.init_task) - LOAD_OFFSET) {
+ *(.data.init_task)
+ }

. = ALIGN(4096);
- .data.page_aligned : { *(.data.page_aligned) }
+ .data.page_aligned : AT(ADDR(.data.page_aligned) - LOAD_OFFSET) {
+ *(.data.page_aligned)
+ }

. = ALIGN(4096); /* Init code and data */
__init_begin = .;
- .init.text : {
+ .init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {
_sinittext = .;
*(.init.text)
_einittext = .;
}
__initdata_begin = .;
- .init.data : { *(.init.data) }
+ .init.data : AT(ADDR(.init.data) - LOAD_OFFSET) { *(.init.data) }
__initdata_end = .;
. = ALIGN(16);
__setup_start = .;
- .init.setup : { *(.init.setup) }
+ .init.setup : AT(ADDR(.init.setup) - LOAD_OFFSET) { *(.init.setup) }
__setup_end = .;
__initcall_start = .;
- .initcall.init : {
+ .initcall.init : AT(ADDR(.initcall.init) - LOAD_OFFSET) {
*(.initcall1.init)
*(.initcall2.init)
*(.initcall3.init)
@@ -105,32 +143,38 @@
}
__initcall_end = .;
__con_initcall_start = .;
- .con_initcall.init : { *(.con_initcall.init) }
+ .con_initcall.init : AT(ADDR(.con_initcall.init) - LOAD_OFFSET) {
+ *(.con_initcall.init)
+ }
__con_initcall_end = .;
SECURITY_INIT
. = ALIGN(8);
__alt_instructions = .;
- .altinstructions : { *(.altinstructions) }
+ .altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) {
+ *(.altinstructions)
+ }
__alt_instructions_end = .;
- .altinstr_replacement : { *(.altinstr_replacement) }
+ .altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) {
+ *(.altinstr_replacement)
+ }
/* .exit.text is discard at runtime, not link time, to deal with references
from .altinstructions and .eh_frame */
- .exit.text : { *(.exit.text) }
- .exit.data : { *(.exit.data) }
+ .exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) { *(.exit.text) }
+ .exit.data : AT(ADDR(.ext.data) - LOAD_OFFSET) { *(.exit.data) }
. = ALIGN(4096);
__initramfs_start = .;
- .init.ramfs : { *(.init.ramfs) }
+ .init.ramfs : AT(ADDR(.init.ramfs) - LOAD_OFFSET) { *(.init.ramfs) }
__initramfs_end = .;
. = ALIGN(32);
__per_cpu_start = .;
- .data.percpu : { *(.data.percpu) }
+ .data.percpu : AT(ADDR(.data.percpu) - LOAD_OFFSET) { *(.data.percpu) }
__per_cpu_end = .;
. = ALIGN(4096);
__init_end = .;

. = ALIGN(4096);
__nosave_begin = .;
- .data_nosave : { *(.data.nosave) }
+ .data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) { *(.data.nosave) }
. = ALIGN(4096);
__nosave_end = .;

-
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