linux-kernel-test/arch/i386/kernel/vmlinux.lds.S
Jan Beulich 6fb14755a6 [PATCH] x86: tighten kernel image page access rights
On x86-64, kernel memory freed after init can be entirely unmapped instead
of just getting 'poisoned' by overwriting with a debug pattern.

On i386 and x86-64 (under CONFIG_DEBUG_RODATA), kernel text and bug table
can also be write-protected.

Compared to the first version, this one prevents re-creating deleted
mappings in the kernel image range on x86-64, if those got removed
previously. This, together with the original changes, prevents temporarily
having inconsistent mappings when cacheability attributes are being
changed on such pages (e.g. from AGP code). While on i386 such duplicate
mappings don't exist, the same change is done there, too, both for
consistency and because checking pte_present() before using various other
pte_XXX functions is a requirement anyway. At once, i386 code gets
adjusted to use pte_huge() instead of open coding this.

AK: split out cpa() changes

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2007-05-02 19:27:10 +02:00

230 lines
5.8 KiB
ArmAsm

/* ld script to make i386 Linux kernel
* Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>;
*
* Don't define absolute symbols until and unless you know that symbol
* value is should remain constant even if kernel image is relocated
* at run time. Absolute symbols are not relocated. If symbol value should
* change if kernel is relocated, make the symbol section relative and
* put it inside the section definition.
*/
/* Don't define absolute symbols until and unless you know that symbol
* value is should remain constant even if kernel image is relocated
* at run time. Absolute symbols are not relocated. If symbol value should
* change if kernel is relocated, make the symbol section relative and
* put it inside the section definition.
*/
#define LOAD_OFFSET __PAGE_OFFSET
#include <asm-generic/vmlinux.lds.h>
#include <asm/thread_info.h>
#include <asm/page.h>
#include <asm/cache.h>
#include <asm/boot.h>
OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
OUTPUT_ARCH(i386)
ENTRY(phys_startup_32)
jiffies = jiffies_64;
_proxy_pda = 1;
PHDRS {
text PT_LOAD FLAGS(5); /* R_E */
data PT_LOAD FLAGS(7); /* RWE */
note PT_NOTE FLAGS(4); /* R__ */
}
SECTIONS
{
. = LOAD_OFFSET + LOAD_PHYSICAL_ADDR;
phys_startup_32 = startup_32 - LOAD_OFFSET;
.text.head : AT(ADDR(.text.head) - LOAD_OFFSET) {
_text = .; /* Text and read-only data */
*(.text.head)
} :text = 0x9090
/* read-only */
.text : AT(ADDR(.text) - LOAD_OFFSET) {
*(.text)
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
*(.fixup)
*(.gnu.warning)
_etext = .; /* End of text section */
} :text = 0x9090
. = ALIGN(16); /* Exception table */
__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
__start___ex_table = .;
*(__ex_table)
__stop___ex_table = .;
}
BUG_TABLE
. = ALIGN(4);
.tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) {
__tracedata_start = .;
*(.tracedata)
__tracedata_end = .;
}
RODATA
/* writeable */
. = ALIGN(4096);
.data : AT(ADDR(.data) - LOAD_OFFSET) { /* Data */
*(.data)
CONSTRUCTORS
} :data
.paravirtprobe : AT(ADDR(.paravirtprobe) - LOAD_OFFSET) {
__start_paravirtprobe = .;
*(.paravirtprobe)
__stop_paravirtprobe = .;
}
. = ALIGN(4096);
.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
__nosave_begin = .;
*(.data.nosave)
. = ALIGN(4096);
__nosave_end = .;
}
. = ALIGN(4096);
.data.page_aligned : AT(ADDR(.data.page_aligned) - LOAD_OFFSET) {
*(.data.idt)
}
. = ALIGN(32);
.data.cacheline_aligned : AT(ADDR(.data.cacheline_aligned) - LOAD_OFFSET) {
*(.data.cacheline_aligned)
}
/* rarely changed data like cpu maps */
. = ALIGN(32);
.data.read_mostly : AT(ADDR(.data.read_mostly) - LOAD_OFFSET) {
*(.data.read_mostly)
_edata = .; /* End of data section */
}
. = ALIGN(THREAD_SIZE); /* init_task */
.data.init_task : AT(ADDR(.data.init_task) - LOAD_OFFSET) {
*(.data.init_task)
}
/* might get freed after init */
. = ALIGN(4096);
.smp_altinstructions : AT(ADDR(.smp_altinstructions) - LOAD_OFFSET) {
__smp_alt_begin = .;
__smp_alt_instructions = .;
*(.smp_altinstructions)
__smp_alt_instructions_end = .;
}
. = ALIGN(4);
.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
__smp_locks = .;
*(.smp_locks)
__smp_locks_end = .;
}
.smp_altinstr_replacement : AT(ADDR(.smp_altinstr_replacement) - LOAD_OFFSET) {
*(.smp_altinstr_replacement)
__smp_alt_end = .;
}
/* will be freed after init
* Following ALIGN() is required to make sure no other data falls on the
* same page where __smp_alt_end is pointing as that page might be freed
* after boot. Always make sure that ALIGN() directive is present after
* the section which contains __smp_alt_end.
*/
. = ALIGN(4096);
/* will be freed after init */
. = ALIGN(4096); /* Init code and data */
.init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {
__init_begin = .;
_sinittext = .;
*(.init.text)
_einittext = .;
}
.init.data : AT(ADDR(.init.data) - LOAD_OFFSET) { *(.init.data) }
. = ALIGN(16);
.init.setup : AT(ADDR(.init.setup) - LOAD_OFFSET) {
__setup_start = .;
*(.init.setup)
__setup_end = .;
}
.initcall.init : AT(ADDR(.initcall.init) - LOAD_OFFSET) {
__initcall_start = .;
INITCALLS
__initcall_end = .;
}
.con_initcall.init : AT(ADDR(.con_initcall.init) - LOAD_OFFSET) {
__con_initcall_start = .;
*(.con_initcall.init)
__con_initcall_end = .;
}
SECURITY_INIT
. = ALIGN(4);
.altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) {
__alt_instructions = .;
*(.altinstructions)
__alt_instructions_end = .;
}
.altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) {
*(.altinstr_replacement)
}
. = ALIGN(4);
.parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
__start_parainstructions = .;
*(.parainstructions)
__stop_parainstructions = .;
}
/* .exit.text is discard at runtime, not link time, to deal with references
from .altinstructions and .eh_frame */
.exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) { *(.exit.text) }
.exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) { *(.exit.data) }
#if defined(CONFIG_BLK_DEV_INITRD)
. = ALIGN(4096);
.init.ramfs : AT(ADDR(.init.ramfs) - LOAD_OFFSET) {
__initramfs_start = .;
*(.init.ramfs)
__initramfs_end = .;
}
#endif
. = ALIGN(L1_CACHE_BYTES);
.data.percpu : AT(ADDR(.data.percpu) - LOAD_OFFSET) {
__per_cpu_start = .;
*(.data.percpu)
__per_cpu_end = .;
}
. = ALIGN(4096);
/* freed after init ends here */
.bss : AT(ADDR(.bss) - LOAD_OFFSET) {
__init_end = .;
__bss_start = .; /* BSS */
*(.bss.page_aligned)
*(.bss)
. = ALIGN(4);
__bss_stop = .;
_end = . ;
/* This is where the kernel creates the early boot page tables */
. = ALIGN(4096);
pg0 = . ;
}
/* Sections to be discarded */
/DISCARD/ : {
*(.exitcall.exit)
}
STABS_DEBUG
DWARF_DEBUG
NOTES
}