Keeping .head.text out of the .text mapping buys us very little: its actual payload is only 4 KB, most of which is padding, but the page alignment may add up to 2 MB (in case of CONFIG_DEBUG_ALIGN_RODATA=y) of additional padding to the uncompressed kernel Image. Also, on 4 KB granule kernels, the 4 KB misalignment of .text forces us to map the adjacent 56 KB of code without the PTE_CONT attribute, and since this region contains things like the vector table and the GIC interrupt handling entry point, this region is likely to benefit from the reduced TLB pressure that results from PTE_CONT mappings. So remove the alignment between the .head.text and .text sections, and use the [_text, _etext) rather than the [_stext, _etext) interval for mapping the .text segment. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
207 lines
4.6 KiB
ArmAsm
207 lines
4.6 KiB
ArmAsm
/*
|
|
* ld script to make ARM Linux kernel
|
|
* taken from the i386 version by Russell King
|
|
* Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
|
|
*/
|
|
|
|
#include <asm-generic/vmlinux.lds.h>
|
|
#include <asm/cache.h>
|
|
#include <asm/kernel-pgtable.h>
|
|
#include <asm/thread_info.h>
|
|
#include <asm/memory.h>
|
|
#include <asm/page.h>
|
|
#include <asm/pgtable.h>
|
|
|
|
#include "image.h"
|
|
|
|
/* .exit.text needed in case of alternative patching */
|
|
#define ARM_EXIT_KEEP(x) x
|
|
#define ARM_EXIT_DISCARD(x)
|
|
|
|
OUTPUT_ARCH(aarch64)
|
|
ENTRY(_text)
|
|
|
|
jiffies = jiffies_64;
|
|
|
|
#define HYPERVISOR_TEXT \
|
|
/* \
|
|
* Align to 4 KB so that \
|
|
* a) the HYP vector table is at its minimum \
|
|
* alignment of 2048 bytes \
|
|
* b) the HYP init code will not cross a page \
|
|
* boundary if its size does not exceed \
|
|
* 4 KB (see related ASSERT() below) \
|
|
*/ \
|
|
. = ALIGN(SZ_4K); \
|
|
VMLINUX_SYMBOL(__hyp_idmap_text_start) = .; \
|
|
*(.hyp.idmap.text) \
|
|
VMLINUX_SYMBOL(__hyp_idmap_text_end) = .; \
|
|
VMLINUX_SYMBOL(__hyp_text_start) = .; \
|
|
*(.hyp.text) \
|
|
VMLINUX_SYMBOL(__hyp_text_end) = .;
|
|
|
|
#define IDMAP_TEXT \
|
|
. = ALIGN(SZ_4K); \
|
|
VMLINUX_SYMBOL(__idmap_text_start) = .; \
|
|
*(.idmap.text) \
|
|
VMLINUX_SYMBOL(__idmap_text_end) = .;
|
|
|
|
/*
|
|
* The size of the PE/COFF section that covers the kernel image, which
|
|
* runs from stext to _edata, must be a round multiple of the PE/COFF
|
|
* FileAlignment, which we set to its minimum value of 0x200. 'stext'
|
|
* itself is 4 KB aligned, so padding out _edata to a 0x200 aligned
|
|
* boundary should be sufficient.
|
|
*/
|
|
PECOFF_FILE_ALIGNMENT = 0x200;
|
|
|
|
#ifdef CONFIG_EFI
|
|
#define PECOFF_EDATA_PADDING \
|
|
.pecoff_edata_padding : { BYTE(0); . = ALIGN(PECOFF_FILE_ALIGNMENT); }
|
|
#else
|
|
#define PECOFF_EDATA_PADDING
|
|
#endif
|
|
|
|
#if defined(CONFIG_DEBUG_ALIGN_RODATA)
|
|
#define ALIGN_DEBUG_RO . = ALIGN(1<<SECTION_SHIFT);
|
|
#define ALIGN_DEBUG_RO_MIN(min) ALIGN_DEBUG_RO
|
|
#elif defined(CONFIG_DEBUG_RODATA)
|
|
#define ALIGN_DEBUG_RO . = ALIGN(1<<PAGE_SHIFT);
|
|
#define ALIGN_DEBUG_RO_MIN(min) ALIGN_DEBUG_RO
|
|
#else
|
|
#define ALIGN_DEBUG_RO
|
|
#define ALIGN_DEBUG_RO_MIN(min) . = ALIGN(min);
|
|
#endif
|
|
|
|
SECTIONS
|
|
{
|
|
/*
|
|
* XXX: The linker does not define how output sections are
|
|
* assigned to input sections when there are multiple statements
|
|
* matching the same input section name. There is no documented
|
|
* order of matching.
|
|
*/
|
|
/DISCARD/ : {
|
|
ARM_EXIT_DISCARD(EXIT_TEXT)
|
|
ARM_EXIT_DISCARD(EXIT_DATA)
|
|
EXIT_CALL
|
|
*(.discard)
|
|
*(.discard.*)
|
|
*(.interp .dynamic)
|
|
}
|
|
|
|
. = KIMAGE_VADDR + TEXT_OFFSET;
|
|
|
|
.head.text : {
|
|
_text = .;
|
|
HEAD_TEXT
|
|
}
|
|
.text : { /* Real text segment */
|
|
_stext = .; /* Text and read-only data */
|
|
__exception_text_start = .;
|
|
*(.exception.text)
|
|
__exception_text_end = .;
|
|
IRQENTRY_TEXT
|
|
SOFTIRQENTRY_TEXT
|
|
TEXT_TEXT
|
|
SCHED_TEXT
|
|
LOCK_TEXT
|
|
HYPERVISOR_TEXT
|
|
IDMAP_TEXT
|
|
*(.fixup)
|
|
*(.gnu.warning)
|
|
. = ALIGN(16);
|
|
*(.got) /* Global offset table */
|
|
}
|
|
|
|
ALIGN_DEBUG_RO_MIN(PAGE_SIZE)
|
|
RO_DATA(PAGE_SIZE) /* everything from this point to */
|
|
EXCEPTION_TABLE(8) /* _etext will be marked RO NX */
|
|
NOTES
|
|
|
|
ALIGN_DEBUG_RO_MIN(PAGE_SIZE)
|
|
_etext = .; /* End of text and rodata section */
|
|
__init_begin = .;
|
|
|
|
INIT_TEXT_SECTION(8)
|
|
.exit.text : {
|
|
ARM_EXIT_KEEP(EXIT_TEXT)
|
|
}
|
|
|
|
.init.data : {
|
|
INIT_DATA
|
|
INIT_SETUP(16)
|
|
INIT_CALLS
|
|
CON_INITCALL
|
|
SECURITY_INITCALL
|
|
INIT_RAM_FS
|
|
*(.init.rodata.* .init.bss) /* from the EFI stub */
|
|
}
|
|
.exit.data : {
|
|
ARM_EXIT_KEEP(EXIT_DATA)
|
|
}
|
|
|
|
PERCPU_SECTION(L1_CACHE_BYTES)
|
|
|
|
. = ALIGN(4);
|
|
.altinstructions : {
|
|
__alt_instructions = .;
|
|
*(.altinstructions)
|
|
__alt_instructions_end = .;
|
|
}
|
|
.altinstr_replacement : {
|
|
*(.altinstr_replacement)
|
|
}
|
|
.rela : ALIGN(8) {
|
|
__reloc_start = .;
|
|
*(.rela .rela*)
|
|
__reloc_end = .;
|
|
}
|
|
.dynsym : ALIGN(8) {
|
|
__dynsym_start = .;
|
|
*(.dynsym)
|
|
}
|
|
.dynstr : {
|
|
*(.dynstr)
|
|
}
|
|
.hash : {
|
|
*(.hash)
|
|
}
|
|
|
|
. = ALIGN(PAGE_SIZE);
|
|
__init_end = .;
|
|
|
|
_data = .;
|
|
_sdata = .;
|
|
RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
|
|
PECOFF_EDATA_PADDING
|
|
_edata = .;
|
|
|
|
BSS_SECTION(0, 0, 0)
|
|
|
|
. = ALIGN(PAGE_SIZE);
|
|
idmap_pg_dir = .;
|
|
. += IDMAP_DIR_SIZE;
|
|
swapper_pg_dir = .;
|
|
. += SWAPPER_DIR_SIZE;
|
|
|
|
_end = .;
|
|
|
|
STABS_DEBUG
|
|
|
|
HEAD_SYMBOLS
|
|
}
|
|
|
|
/*
|
|
* The HYP init code and ID map text can't be longer than a page each,
|
|
* and should not cross a page boundary.
|
|
*/
|
|
ASSERT(__hyp_idmap_text_end - (__hyp_idmap_text_start & ~(SZ_4K - 1)) <= SZ_4K,
|
|
"HYP init code too big or misaligned")
|
|
ASSERT(__idmap_text_end - (__idmap_text_start & ~(SZ_4K - 1)) <= SZ_4K,
|
|
"ID map text too big or misaligned")
|
|
|
|
/*
|
|
* If padding is applied before .head.text, virt<->phys conversions will fail.
|
|
*/
|
|
ASSERT(_text == (KIMAGE_VADDR + TEXT_OFFSET), "HEAD is misaligned")
|