diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index bc96c8a7fc79..b63baa749609 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -14,7 +14,9 @@ #include #include +#include #include +#include #include "cpu-reset.h" @@ -22,8 +24,6 @@ extern const unsigned char arm64_relocate_new_kernel[]; extern const unsigned long arm64_relocate_new_kernel_size; -static unsigned long kimage_start; - /** * kexec_image_info - For debugging output. */ @@ -64,8 +64,6 @@ void machine_kexec_cleanup(struct kimage *kimage) */ int machine_kexec_prepare(struct kimage *kimage) { - kimage_start = kimage->start; - kexec_image_info(kimage); if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) { @@ -183,7 +181,7 @@ void machine_kexec(struct kimage *kimage) kexec_list_flush(kimage); /* Flush the new image if already in place. */ - if (kimage->head & IND_DONE) + if ((kimage != kexec_crash_image) && (kimage->head & IND_DONE)) kexec_segment_flush(kimage); pr_info("Bye!\n"); @@ -201,7 +199,7 @@ void machine_kexec(struct kimage *kimage) */ cpu_soft_restart(1, reboot_code_buffer_phys, kimage->head, - kimage_start, 0); + kimage->start, 0); BUG(); /* Should never get here. */ } @@ -210,3 +208,25 @@ void machine_crash_shutdown(struct pt_regs *regs) { /* Empty routine needed to avoid build errors. */ } + +void arch_kexec_protect_crashkres(void) +{ + int i; + + kexec_segment_flush(kexec_crash_image); + + for (i = 0; i < kexec_crash_image->nr_segments; i++) + set_memory_valid( + __phys_to_virt(kexec_crash_image->segment[i].mem), + kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 0); +} + +void arch_kexec_unprotect_crashkres(void) +{ + int i; + + for (i = 0; i < kexec_crash_image->nr_segments; i++) + set_memory_valid( + __phys_to_virt(kexec_crash_image->segment[i].mem), + kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 1); +} diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 91502e36e6d9..0c429ec6fde8 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -22,6 +22,8 @@ #include #include #include +#include +#include #include #include #include @@ -393,56 +395,11 @@ static void update_mapping_prot(phys_addr_t phys, unsigned long virt, flush_tlb_kernel_range(virt, virt + size); } -static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, phys_addr_t end) +static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, + phys_addr_t end, pgprot_t prot, int flags) { - phys_addr_t kernel_start = __pa_symbol(_text); - phys_addr_t kernel_end = __pa_symbol(__init_begin); - int flags = 0; - - if (debug_pagealloc_enabled()) - flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; - - /* - * Take care not to create a writable alias for the - * read-only text and rodata sections of the kernel image. - */ - - /* No overlap with the kernel text/rodata */ - if (end < kernel_start || start >= kernel_end) { - __create_pgd_mapping(pgd, start, __phys_to_virt(start), - end - start, PAGE_KERNEL, - early_pgtable_alloc, flags); - return; - } - - /* - * This block overlaps the kernel text/rodata mappings. - * Map the portion(s) which don't overlap. - */ - if (start < kernel_start) - __create_pgd_mapping(pgd, start, - __phys_to_virt(start), - kernel_start - start, PAGE_KERNEL, - early_pgtable_alloc, flags); - if (kernel_end < end) - __create_pgd_mapping(pgd, kernel_end, - __phys_to_virt(kernel_end), - end - kernel_end, PAGE_KERNEL, - early_pgtable_alloc, flags); - - /* - * Map the linear alias of the [_text, __init_begin) interval - * as non-executable now, and remove the write permission in - * mark_linear_text_alias_ro() below (which will be called after - * alternative patching has completed). This makes the contents - * of the region accessible to subsystems such as hibernate, - * but protects it from inadvertent modification or execution. - * Note that contiguous mappings cannot be remapped in this way, - * so we should avoid them here. - */ - __create_pgd_mapping(pgd, kernel_start, __phys_to_virt(kernel_start), - kernel_end - kernel_start, PAGE_KERNEL, - early_pgtable_alloc, NO_CONT_MAPPINGS); + __create_pgd_mapping(pgd, start, __phys_to_virt(start), end - start, + prot, early_pgtable_alloc, flags); } void __init mark_linear_text_alias_ro(void) @@ -457,7 +414,26 @@ void __init mark_linear_text_alias_ro(void) static void __init map_mem(pgd_t *pgd) { + phys_addr_t kernel_start = __pa_symbol(_text); + phys_addr_t kernel_end = __pa_symbol(__init_begin); struct memblock_region *reg; + int flags = 0; + + if (debug_pagealloc_enabled()) + flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; + + /* + * Take care not to create a writable alias for the + * read-only text and rodata sections of the kernel image. + * So temporarily mark them as NOMAP to skip mappings in + * the following for-loop + */ + memblock_mark_nomap(kernel_start, kernel_end - kernel_start); +#ifdef CONFIG_KEXEC_CORE + if (crashk_res.end) + memblock_mark_nomap(crashk_res.start, + resource_size(&crashk_res)); +#endif /* map all the memory banks */ for_each_memblock(memory, reg) { @@ -469,8 +445,37 @@ static void __init map_mem(pgd_t *pgd) if (memblock_is_nomap(reg)) continue; - __map_memblock(pgd, start, end); + __map_memblock(pgd, start, end, PAGE_KERNEL, flags); } + + /* + * Map the linear alias of the [_text, __init_begin) interval + * as non-executable now, and remove the write permission in + * mark_linear_text_alias_ro() below (which will be called after + * alternative patching has completed). This makes the contents + * of the region accessible to subsystems such as hibernate, + * but protects it from inadvertent modification or execution. + * Note that contiguous mappings cannot be remapped in this way, + * so we should avoid them here. + */ + __map_memblock(pgd, kernel_start, kernel_end, + PAGE_KERNEL, NO_CONT_MAPPINGS); + memblock_clear_nomap(kernel_start, kernel_end - kernel_start); + +#ifdef CONFIG_KEXEC_CORE + /* + * Use page-level mappings here so that we can shrink the region + * in page granularity and put back unused memory to buddy system + * through /sys/kernel/kexec_crash_size interface. + */ + if (crashk_res.end) { + __map_memblock(pgd, crashk_res.start, crashk_res.end + 1, + PAGE_KERNEL, + NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS); + memblock_clear_nomap(crashk_res.start, + resource_size(&crashk_res)); + } +#endif } void mark_rodata_ro(void)