linux/arch/x86/kernel/vmlinux_64.lds.S
Jeremy Fitzhardinge 796216a57f x86: allow extend_brk users to reserve brk space
Impact: new interface; remove hard-coded limit

Add RESERVE_BRK(name, size) macro to reserve space in the brk
area.  This should be a conservative (ie, larger) estimate of
how much space might possibly be required from the brk area.
Any unused space will be freed, so there's no real downside
on making the reservation too large (within limits).

The name should be unique within a given file, and somewhat
descriptive.

The C definition of RESERVE_BRK() ends up being more complex than
one would expect to work around a cluster of gcc infelicities:

  The first attempt was to simply try putting __section(.brk_reservation)
  on a variable.  This doesn't work because it ends up making it a
  @progbits section, which gets actual space allocated in the vmlinux
  executable.

  The second attempt was to emit the space into a section using asm,
  but gcc doesn't allow arguments to be passed to file-level asm()
  statements, making it hard to pass in the size.

  The final attempt is to wrap the asm() in a function to allow
  it to have arguments, and put the function itself into the
  .discard section, which vmlinux*.lds drops entirely from the
  emitted vmlinux.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-03-14 17:23:47 -07:00

297 lines
7.4 KiB
ArmAsm

/* ld script to make x86-64 Linux kernel
* Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>;
*/
#define LOAD_OFFSET __START_KERNEL_map
#include <asm-generic/vmlinux.lds.h>
#include <asm/asm-offsets.h>
#include <asm/page_types.h>
#undef i386 /* in case the preprocessor is a 32bit one */
OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64", "elf64-x86-64")
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 */
user PT_LOAD FLAGS(7); /* RWE */
data.init PT_LOAD FLAGS(7); /* RWE */
#ifdef CONFIG_SMP
percpu PT_LOAD FLAGS(7); /* RWE */
#endif
data.init2 PT_LOAD FLAGS(7); /* RWE */
note PT_NOTE FLAGS(0); /* ___ */
}
SECTIONS
{
. = __START_KERNEL;
phys_startup_64 = startup_64 - LOAD_OFFSET;
.text : AT(ADDR(.text) - LOAD_OFFSET) {
_text = .; /* Text and read-only data */
/* First the code that has to be first for bootstrapping */
*(.text.head)
_stext = .;
/* Then the rest */
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
*(.fixup)
*(.gnu.warning)
_etext = .; /* End of text section */
} :text = 0x9090
NOTES :text :note
. = ALIGN(16); /* Exception table */
__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
__start___ex_table = .;
*(__ex_table)
__stop___ex_table = .;
} :text = 0x9090
RODATA
. = ALIGN(PAGE_SIZE); /* Align data segment to page size boundary */
/* Data */
.data : AT(ADDR(.data) - LOAD_OFFSET) {
DATA_DATA
CONSTRUCTORS
_edata = .; /* End of data section */
} :data
.data.cacheline_aligned : AT(ADDR(.data.cacheline_aligned) - LOAD_OFFSET) {
. = ALIGN(PAGE_SIZE);
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
*(.data.cacheline_aligned)
}
. = ALIGN(CONFIG_X86_INTERNODE_CACHE_BYTES);
.data.read_mostly : AT(ADDR(.data.read_mostly) - LOAD_OFFSET) {
*(.data.read_mostly)
}
#define VSYSCALL_ADDR (-10*1024*1024)
#define VSYSCALL_PHYS_ADDR ((LOADADDR(.data.read_mostly) + SIZEOF(.data.read_mostly) + 4095) & ~(4095))
#define VSYSCALL_VIRT_ADDR ((ADDR(.data.read_mostly) + SIZEOF(.data.read_mostly) + 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) } :user
__vsyscall_0 = VSYSCALL_VIRT_ADDR;
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
.vsyscall_fn : AT(VLOAD(.vsyscall_fn)) { *(.vsyscall_fn) }
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
.vsyscall_gtod_data : AT(VLOAD(.vsyscall_gtod_data))
{ *(.vsyscall_gtod_data) }
vsyscall_gtod_data = VVIRT(.vsyscall_gtod_data);
.vsyscall_clock : AT(VLOAD(.vsyscall_clock))
{ *(.vsyscall_clock) }
vsyscall_clock = VVIRT(.vsyscall_clock);
.vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1))
{ *(.vsyscall_1) }
.vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2))
{ *(.vsyscall_2) }
.vgetcpu_mode : AT(VLOAD(.vgetcpu_mode)) { *(.vgetcpu_mode) }
vgetcpu_mode = VVIRT(.vgetcpu_mode);
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
.jiffies : AT(VLOAD(.jiffies)) { *(.jiffies) }
jiffies = VVIRT(.jiffies);
.vsyscall_3 ADDR(.vsyscall_0) + 3072: AT(VLOAD(.vsyscall_3))
{ *(.vsyscall_3) }
. = VSYSCALL_VIRT_ADDR + PAGE_SIZE;
#undef VSYSCALL_ADDR
#undef VSYSCALL_PHYS_ADDR
#undef VSYSCALL_VIRT_ADDR
#undef VLOAD_OFFSET
#undef VLOAD
#undef VVIRT_OFFSET
#undef VVIRT
.data.init_task : AT(ADDR(.data.init_task) - LOAD_OFFSET) {
. = ALIGN(THREAD_SIZE); /* init_task */
*(.data.init_task)
}:data.init
.data.page_aligned : AT(ADDR(.data.page_aligned) - LOAD_OFFSET) {
. = ALIGN(PAGE_SIZE);
*(.data.page_aligned)
}
.smp_locks : AT(ADDR(.smp_locks) - LOAD_OFFSET) {
/* might get freed after init */
. = ALIGN(PAGE_SIZE);
__smp_alt_begin = .;
__smp_locks = .;
*(.smp_locks)
__smp_locks_end = .;
. = ALIGN(PAGE_SIZE);
__smp_alt_end = .;
}
. = ALIGN(PAGE_SIZE); /* Init code and data */
__init_begin = .; /* paired with __init_end */
.init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {
_sinittext = .;
INIT_TEXT
_einittext = .;
}
.init.data : AT(ADDR(.init.data) - LOAD_OFFSET) {
__initdata_begin = .;
INIT_DATA
__initdata_end = .;
}
.init.setup : AT(ADDR(.init.setup) - LOAD_OFFSET) {
. = ALIGN(16);
__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 = .;
}
.x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) {
__x86_cpu_dev_start = .;
*(.x86_cpu_dev.init)
__x86_cpu_dev_end = .;
}
SECURITY_INIT
. = ALIGN(8);
.parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) {
__parainstructions = .;
*(.parainstructions)
__parainstructions_end = .;
}
.altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) {
. = ALIGN(8);
__alt_instructions = .;
*(.altinstructions)
__alt_instructions_end = .;
}
.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 : AT(ADDR(.exit.text) - LOAD_OFFSET) {
EXIT_TEXT
}
.exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) {
EXIT_DATA
}
#ifdef CONFIG_BLK_DEV_INITRD
. = ALIGN(PAGE_SIZE);
.init.ramfs : AT(ADDR(.init.ramfs) - LOAD_OFFSET) {
__initramfs_start = .;
*(.init.ramfs)
__initramfs_end = .;
}
#endif
#ifdef CONFIG_SMP
/*
* percpu offsets are zero-based on SMP. PERCPU_VADDR() changes the
* output PHDR, so the next output section - __data_nosave - should
* start another section data.init2. Also, pda should be at the head of
* percpu area. Preallocate it and define the percpu offset symbol
* so that it can be accessed as a percpu variable.
*/
. = ALIGN(PAGE_SIZE);
PERCPU_VADDR(0, :percpu)
#else
PERCPU(PAGE_SIZE)
#endif
. = ALIGN(PAGE_SIZE);
__init_end = .;
.data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) {
. = ALIGN(PAGE_SIZE);
__nosave_begin = .;
*(.data.nosave)
. = ALIGN(PAGE_SIZE);
__nosave_end = .;
} :data.init2 /* use another section data.init2, see PERCPU_VADDR() above */
.bss : AT(ADDR(.bss) - LOAD_OFFSET) {
. = ALIGN(PAGE_SIZE);
__bss_start = .; /* BSS */
*(.bss.page_aligned)
*(.bss)
__bss_stop = .;
. = ALIGN(PAGE_SIZE);
__brk_base = . ;
. += 64 * 1024; /* 64k slop space */
*(.brk_reservation) /* areas brk users have reserved */
__brk_limit = . ;
}
_end = . ;
/* Sections to be discarded */
/DISCARD/ : {
*(.exitcall.exit)
*(.eh_frame)
*(.discard)
}
STABS_DEBUG
DWARF_DEBUG
}
/*
* Per-cpu symbols which need to be offset from __per_cpu_load
* for the boot processor.
*/
#define INIT_PER_CPU(x) init_per_cpu__##x = per_cpu__##x + __per_cpu_load
INIT_PER_CPU(gdt_page);
INIT_PER_CPU(irq_stack_union);
/*
* Build-time check on the image size:
*/
ASSERT((_end - _text <= KERNEL_IMAGE_SIZE),
"kernel image bigger than KERNEL_IMAGE_SIZE")
#ifdef CONFIG_SMP
ASSERT((per_cpu__irq_stack_union == 0),
"irq_stack_union is not at start of per-cpu area");
#endif
#ifdef CONFIG_KEXEC
#include <asm/kexec.h>
ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE,
"kexec control code size is too big")
#endif