linux/arch/mips/kernel/vmlinux.lds.S
Matt Redfearn 069fd76627 MIPS: Reserve space for relocation table
When CONFIG_RELOCATABLE is enabled, add a new section in the memory map
to be filled with relocation data.

CONFIG_RELOCATION_TABLE_SIZE allows the amount of space reserved to be
adjusted if necessary.

The relocs tool will populate this reserved space with relocation
information. The space is reserved within the elf by filling it with
0's, and an invalid entry is left at the start of the space such that
kernel relocation will be aborted if the table is empty.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Aaro Koskinen <aaro.koskinen@nokia.com>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: kernel-hardening@lists.openwall.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12982/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13 14:02:02 +02:00

226 lines
4.7 KiB
ArmAsm

#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#define PAGE_SIZE _PAGE_SIZE
/*
* Put .bss..swapper_pg_dir as the first thing in .bss. This will
* ensure that it has .bss alignment (64K).
*/
#define BSS_FIRST_SECTIONS *(.bss..swapper_pg_dir)
#include <asm-generic/vmlinux.lds.h>
#undef mips
#define mips mips
OUTPUT_ARCH(mips)
ENTRY(kernel_entry)
PHDRS {
text PT_LOAD FLAGS(7); /* RWX */
#ifndef CONFIG_CAVIUM_OCTEON_SOC
note PT_NOTE FLAGS(4); /* R__ */
#endif /* CAVIUM_OCTEON_SOC */
}
#ifdef CONFIG_32BIT
#ifdef CONFIG_CPU_LITTLE_ENDIAN
jiffies = jiffies_64;
#else
jiffies = jiffies_64 + 4;
#endif
#else
jiffies = jiffies_64;
#endif
SECTIONS
{
#ifdef CONFIG_BOOT_ELF64
/* Read-only sections, merged into text segment: */
/* . = 0xc000000000000000; */
/* This is the value for an Origin kernel, taken from an IRIX kernel. */
/* . = 0xc00000000001c000; */
/* Set the vaddr for the text segment to a value
* >= 0xa800 0000 0001 9000 if no symmon is going to configured
* >= 0xa800 0000 0030 0000 otherwise
*/
/* . = 0xa800000000300000; */
. = 0xffffffff80300000;
#endif
. = VMLINUX_LOAD_ADDRESS;
/* read-only */
_text = .; /* Text and read-only data */
.text : {
TEXT_TEXT
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
*(.text.*)
*(.fixup)
*(.gnu.warning)
} :text = 0
_etext = .; /* End of text section */
EXCEPTION_TABLE(16)
/* Exception table for data bus errors */
__dbe_table : {
__start___dbe_table = .;
*(__dbe_table)
__stop___dbe_table = .;
}
#ifdef CONFIG_CAVIUM_OCTEON_SOC
#define NOTES_HEADER
#else /* CONFIG_CAVIUM_OCTEON_SOC */
#define NOTES_HEADER :note
#endif /* CONFIG_CAVIUM_OCTEON_SOC */
NOTES :text NOTES_HEADER
.dummy : { *(.dummy) } :text
_sdata = .; /* Start of data section */
RODATA
/* writeable */
.data : { /* Data */
. = . + DATAOFFSET; /* for CONFIG_MAPPED_KERNEL */
INIT_TASK_DATA(THREAD_SIZE)
NOSAVE_DATA
CACHELINE_ALIGNED_DATA(1 << CONFIG_MIPS_L1_CACHE_SHIFT)
READ_MOSTLY_DATA(1 << CONFIG_MIPS_L1_CACHE_SHIFT)
DATA_DATA
CONSTRUCTORS
}
_gp = . + 0x8000;
.lit8 : {
*(.lit8)
}
.lit4 : {
*(.lit4)
}
/* We want the small data sections together, so single-instruction offsets
can access them all, and initialized data all before uninitialized, so
we can shorten the on-disk segment size. */
.sdata : {
*(.sdata)
}
_edata = .; /* End of data section */
/* will be freed after init */
. = ALIGN(PAGE_SIZE); /* Init code and data */
__init_begin = .;
INIT_TEXT_SECTION(PAGE_SIZE)
INIT_DATA_SECTION(16)
. = ALIGN(4);
.mips.machines.init : AT(ADDR(.mips.machines.init) - LOAD_OFFSET) {
__mips_machines_start = .;
*(.mips.machines.init)
__mips_machines_end = .;
}
/* .exit.text is discarded at runtime, not link time, to deal with
* references from .rodata
*/
.exit.text : {
EXIT_TEXT
}
.exit.data : {
EXIT_DATA
}
#ifdef CONFIG_SMP
PERCPU_SECTION(1 << CONFIG_MIPS_L1_CACHE_SHIFT)
#endif
#ifdef CONFIG_RELOCATABLE
. = ALIGN(4);
.data.reloc : {
_relocation_start = .;
/*
* Space for relocation table
* This needs to be filled so that the
* relocs tool can overwrite the content.
* An invalid value is left at the start of the
* section to abort relocation if the table
* has not been filled in.
*/
LONG(0xFFFFFFFF);
FILL(0);
. += CONFIG_RELOCATION_TABLE_SIZE - 4;
_relocation_end = .;
}
#endif
#ifdef CONFIG_MIPS_RAW_APPENDED_DTB
__appended_dtb = .;
/* leave space for appended DTB */
. += 0x100000;
#elif defined(CONFIG_MIPS_ELF_APPENDED_DTB)
.appended_dtb : AT(ADDR(.appended_dtb) - LOAD_OFFSET) {
*(.appended_dtb)
KEEP(*(.appended_dtb))
}
#endif
/*
* Align to 64K in attempt to eliminate holes before the
* .bss..swapper_pg_dir section at the start of .bss. This
* also satisfies PAGE_SIZE alignment as the largest page size
* allowed is 64K.
*/
. = ALIGN(0x10000);
__init_end = .;
/* freed after init ends here */
/*
* Force .bss to 64K alignment so that .bss..swapper_pg_dir
* gets that alignment. .sbss should be empty, so there will be
* no holes after __init_end. */
BSS_SECTION(0, 0x10000, 0)
_end = . ;
/* These mark the ABI of the kernel for debuggers. */
.mdebug.abi32 : {
KEEP(*(.mdebug.abi32))
}
.mdebug.abi64 : {
KEEP(*(.mdebug.abi64))
}
/* This is the MIPS specific mdebug section. */
.mdebug : {
*(.mdebug)
}
STABS_DEBUG
DWARF_DEBUG
/* These must appear regardless of . */
.gptab.sdata : {
*(.gptab.data)
*(.gptab.sdata)
}
.gptab.sbss : {
*(.gptab.bss)
*(.gptab.sbss)
}
/* Sections to be discarded */
DISCARDS
/DISCARD/ : {
/* ABI crap starts here */
*(.MIPS.abiflags)
*(.MIPS.options)
*(.options)
*(.pdr)
*(.reginfo)
*(.eh_frame)
}
}