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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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d07a980c1b
On s390 __ro_after_init is currently mapped to __read_mostly which means that data marked as __ro_after_init will not be protected. Reason for this is that the common code __ro_after_init implementation is x86 centric: the ro_after_init data section was added to rodata, since x86 enables write protection to kernel text and rodata very late. On s390 we have write protection for these sections enabled with the initial page tables. So adding the ro_after_init data section to rodata does not work on s390. In order to make __ro_after_init work properly on s390 move the ro_after_init data, right behind rodata. Unlike the rodata section it will be marked read-only later after all init calls happened. This s390 specific implementation adds new __start_ro_after_init and __end_ro_after_init labels. Everything in between will be marked read-only after the init calls happened. In addition to the __ro_after_init data move also the exception table there, since from a practical point of view it fits the __ro_after_init requirements. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
111 lines
2.1 KiB
ArmAsm
111 lines
2.1 KiB
ArmAsm
/* ld script to make s390 Linux kernel
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* Written by Martin Schwidefsky (schwidefsky@de.ibm.com)
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*/
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#include <asm/thread_info.h>
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#include <asm/page.h>
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/*
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* Put .bss..swapper_pg_dir as the first thing in .bss. This will
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* make sure it has 16k alignment.
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*/
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#define BSS_FIRST_SECTIONS *(.bss..swapper_pg_dir)
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/* Handle ro_after_init data on our own. */
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#define RO_AFTER_INIT_DATA
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#include <asm-generic/vmlinux.lds.h>
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OUTPUT_FORMAT("elf64-s390", "elf64-s390", "elf64-s390")
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OUTPUT_ARCH(s390:64-bit)
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ENTRY(startup)
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jiffies = jiffies_64;
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PHDRS {
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text PT_LOAD FLAGS(5); /* R_E */
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data PT_LOAD FLAGS(7); /* RWE */
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note PT_NOTE FLAGS(0); /* ___ */
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}
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SECTIONS
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{
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. = 0x00000000;
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.text : {
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_text = .; /* Text and read-only data */
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HEAD_TEXT
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TEXT_TEXT
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SCHED_TEXT
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LOCK_TEXT
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KPROBES_TEXT
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IRQENTRY_TEXT
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SOFTIRQENTRY_TEXT
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*(.fixup)
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*(.gnu.warning)
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} :text = 0x0700
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_etext = .; /* End of text section */
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NOTES :text :note
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.dummy : { *(.dummy) } :data
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RO_DATA_SECTION(PAGE_SIZE)
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#ifdef CONFIG_SHARED_KERNEL
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. = ALIGN(0x100000); /* VM shared segments are 1MB aligned */
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#endif
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. = ALIGN(PAGE_SIZE);
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_eshared = .; /* End of shareable data */
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_sdata = .; /* Start of data section */
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. = ALIGN(PAGE_SIZE);
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__start_ro_after_init = .;
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.data..ro_after_init : {
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*(.data..ro_after_init)
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}
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EXCEPTION_TABLE(16)
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. = ALIGN(PAGE_SIZE);
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__end_ro_after_init = .;
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RW_DATA_SECTION(0x100, PAGE_SIZE, THREAD_SIZE)
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_edata = .; /* End of data section */
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/* will be freed after init */
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. = ALIGN(PAGE_SIZE); /* Init code and data */
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__init_begin = .;
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INIT_TEXT_SECTION(PAGE_SIZE)
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/*
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* .exit.text is discarded at runtime, not link time,
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* to deal with references from __bug_table
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*/
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.exit.text : {
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EXIT_TEXT
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}
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.exit.data : {
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EXIT_DATA
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}
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/* early.c uses stsi, which requires page aligned data. */
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. = ALIGN(PAGE_SIZE);
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INIT_DATA_SECTION(0x100)
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PERCPU_SECTION(0x100)
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. = ALIGN(PAGE_SIZE);
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__init_end = .; /* freed after init ends here */
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BSS_SECTION(PAGE_SIZE, 4 * PAGE_SIZE, PAGE_SIZE)
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_end = . ;
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/* Debugging sections. */
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STABS_DEBUG
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DWARF_DEBUG
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/* Sections to be discarded */
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DISCARDS
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}
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