da57a369d3
The arm64 Image header contains a text_offset field which bootloaders are supposed to read to determine the offset (from a 2MB aligned "start of memory" per booting.txt) at which to load the kernel. The offset is not well respected by bootloaders at present, and due to the lack of variation there is little incentive to support it. This is unfortunate for the sake of future kernels where we may wish to vary the text offset (even zeroing it). This patch adds options to arm64 to enable fuzz-testing of text_offset. CONFIG_ARM64_RANDOMIZE_TEXT_OFFSET forces the text offset to a random 16-byte aligned value value in the range [0..2MB) upon a build of the kernel. It is recommended that distribution kernels enable randomization to test bootloaders such that any compliance issues can be fixed early. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Tom Rini <trini@ti.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
132 lines
2.5 KiB
ArmAsm
132 lines
2.5 KiB
ArmAsm
/*
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* ld script to make ARM Linux kernel
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* taken from the i386 version by Russell King
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* Written by Martin Mares <mj@atrey.karlin.mff.cuni.cz>
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*/
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#include <asm-generic/vmlinux.lds.h>
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#include <asm/thread_info.h>
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#include <asm/memory.h>
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#include <asm/page.h>
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#include "image.h"
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#define ARM_EXIT_KEEP(x)
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#define ARM_EXIT_DISCARD(x) x
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OUTPUT_ARCH(aarch64)
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ENTRY(_text)
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jiffies = jiffies_64;
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#define HYPERVISOR_TEXT \
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/* \
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* Force the alignment to be compatible with \
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* the vectors requirements \
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*/ \
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. = ALIGN(2048); \
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VMLINUX_SYMBOL(__hyp_idmap_text_start) = .; \
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*(.hyp.idmap.text) \
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VMLINUX_SYMBOL(__hyp_idmap_text_end) = .; \
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VMLINUX_SYMBOL(__hyp_text_start) = .; \
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*(.hyp.text) \
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VMLINUX_SYMBOL(__hyp_text_end) = .;
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SECTIONS
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{
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/*
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* XXX: The linker does not define how output sections are
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* assigned to input sections when there are multiple statements
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* matching the same input section name. There is no documented
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* order of matching.
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*/
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/DISCARD/ : {
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ARM_EXIT_DISCARD(EXIT_TEXT)
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ARM_EXIT_DISCARD(EXIT_DATA)
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EXIT_CALL
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*(.discard)
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*(.discard.*)
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}
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. = PAGE_OFFSET + TEXT_OFFSET;
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.head.text : {
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_text = .;
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HEAD_TEXT
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}
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.text : { /* Real text segment */
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_stext = .; /* Text and read-only data */
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__exception_text_start = .;
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*(.exception.text)
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__exception_text_end = .;
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IRQENTRY_TEXT
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TEXT_TEXT
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SCHED_TEXT
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LOCK_TEXT
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HYPERVISOR_TEXT
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*(.fixup)
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*(.gnu.warning)
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. = ALIGN(16);
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*(.got) /* Global offset table */
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}
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RO_DATA(PAGE_SIZE)
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EXCEPTION_TABLE(8)
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NOTES
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_etext = .; /* End of text and rodata section */
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. = ALIGN(PAGE_SIZE);
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__init_begin = .;
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INIT_TEXT_SECTION(8)
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.exit.text : {
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ARM_EXIT_KEEP(EXIT_TEXT)
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}
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. = ALIGN(16);
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.init.data : {
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INIT_DATA
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INIT_SETUP(16)
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INIT_CALLS
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CON_INITCALL
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SECURITY_INITCALL
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INIT_RAM_FS
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}
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.exit.data : {
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ARM_EXIT_KEEP(EXIT_DATA)
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}
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PERCPU_SECTION(64)
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__init_end = .;
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. = ALIGN(PAGE_SIZE);
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_data = .;
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_sdata = .;
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RW_DATA_SECTION(64, PAGE_SIZE, THREAD_SIZE)
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_edata = .;
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BSS_SECTION(0, 0, 0)
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. = ALIGN(PAGE_SIZE);
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idmap_pg_dir = .;
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. += IDMAP_DIR_SIZE;
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swapper_pg_dir = .;
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. += SWAPPER_DIR_SIZE;
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_end = .;
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STABS_DEBUG
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HEAD_SYMBOLS
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}
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/*
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* The HYP init code can't be more than a page long.
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*/
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ASSERT(((__hyp_idmap_text_start + PAGE_SIZE) > __hyp_idmap_text_end),
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"HYP init code too big")
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/*
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* If padding is applied before .head.text, virt<->phys conversions will fail.
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*/
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ASSERT(_text == (PAGE_OFFSET + TEXT_OFFSET), "HEAD is misaligned")
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