Enabling crash dump (kdump) includes * prepare contents of ELF header of a core dump file, /proc/vmcore, using crash_prepare_elf64_headers(), and * add two device tree properties, "linux,usable-memory-range" and "linux,elfcorehdr", which represent respectively a memory range to be used by crash dump kernel and the header's location
Signed-off-by: AKASHI Takahiro <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Reviewed-by: James Morse <[email protected]> Cc: Rob Herring <[email protected]> Cc: Frank Rowand <[email protected]> Cc: [email protected] --- arch/arm64/include/asm/kexec.h | 4 ++ arch/arm64/kernel/machine_kexec_file.c | 97 +++++++++++++++++++++++++- 2 files changed, 98 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h index 67e4cb75d1fd..660705515e33 100644 --- a/arch/arm64/include/asm/kexec.h +++ b/arch/arm64/include/asm/kexec.h @@ -99,6 +99,10 @@ static inline void crash_post_resume(void) {} struct kimage_arch { void *dtb; unsigned long dtb_mem; + /* Core ELF header buffer */ + void *elf_headers; + unsigned long elf_headers_mem; + unsigned long elf_headers_sz; }; extern const struct kexec_file_ops kexec_image_ops; diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c index 7e9d5ed3e238..ab296b98d633 100644 --- a/arch/arm64/kernel/machine_kexec_file.c +++ b/arch/arm64/kernel/machine_kexec_file.c @@ -16,11 +16,15 @@ #include <linux/libfdt.h> #include <linux/memblock.h> #include <linux/of_fdt.h> +#include <linux/slab.h> #include <linux/string.h> #include <linux/types.h> +#include <linux/vmalloc.h> #include <asm/byteorder.h> /* relevant device tree properties */ +#define FDT_PSTR_KEXEC_ELFHDR "linux,elfcorehdr" +#define FDT_PSTR_MEM_RANGE "linux,usable-memory-range" #define FDT_PSTR_INITRD_STA "linux,initrd-start" #define FDT_PSTR_INITRD_END "linux,initrd-end" #define FDT_PSTR_BOOTARGS "bootargs" @@ -35,6 +39,10 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image) vfree(image->arch.dtb); image->arch.dtb = NULL; + vfree(image->arch.elf_headers); + image->arch.elf_headers = NULL; + image->arch.elf_headers_sz = 0; + return kexec_image_post_load_cleanup_default(image); } @@ -49,6 +57,22 @@ static int setup_dtb(struct kimage *image, if (nodeoffset < 0) return -EINVAL; + if (image->type == KEXEC_TYPE_CRASH) { + /* add linux,elfcorehdr */ + ret = fdt_setprop_reg(dtb, nodeoffset, FDT_PSTR_KEXEC_ELFHDR, + image->arch.elf_headers_mem, + image->arch.elf_headers_sz); + if (ret) + return (ret == -FDT_ERR_NOSPACE ? -ENOMEM : -EINVAL); + + /* add linux,usable-memory-range */ + ret = fdt_setprop_reg(dtb, nodeoffset, FDT_PSTR_MEM_RANGE, + crashk_res.start, + crashk_res.end - crashk_res.start + 1); + if (ret) + return (ret == -FDT_ERR_NOSPACE ? -ENOMEM : -EINVAL); + } + /* add bootargs */ if (cmdline) { ret = fdt_setprop_string(dtb, nodeoffset, FDT_PSTR_BOOTARGS, @@ -86,7 +110,8 @@ static int setup_dtb(struct kimage *image, } /* - * More space needed so that we can add initrd and bootargs. + * More space needed so that we can add initrd, bootargs, + * userable-memory-range and elfcorehdr. */ #define DTB_EXTRA_SPACE 0x1000 @@ -132,6 +157,43 @@ static int create_dtb(struct kimage *image, } } +static int prepare_elf_headers(void **addr, unsigned long *sz) +{ + struct crash_mem *cmem; + unsigned int nr_ranges; + int ret; + u64 i; + phys_addr_t start, end; + + nr_ranges = 1; /* for exclusion of crashkernel region */ + for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, + MEMBLOCK_NONE, &start, &end, NULL) + nr_ranges++; + + cmem = kmalloc(sizeof(struct crash_mem) + + sizeof(struct crash_mem_range) * nr_ranges, GFP_KERNEL); + if (!cmem) + return -ENOMEM; + + cmem->max_nr_ranges = nr_ranges; + cmem->nr_ranges = 0; + for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, + MEMBLOCK_NONE, &start, &end, NULL) { + cmem->ranges[cmem->nr_ranges].start = start; + cmem->ranges[cmem->nr_ranges].end = end - 1; + cmem->nr_ranges++; + } + + /* Exclude crashkernel region */ + ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end); + + if (!ret) + ret = crash_prepare_elf64_headers(cmem, true, addr, sz); + + kfree(cmem); + return ret; +} + int load_other_segments(struct kimage *image, unsigned long kernel_load_addr, unsigned long kernel_size, @@ -139,14 +201,43 @@ int load_other_segments(struct kimage *image, char *cmdline) { struct kexec_buf kbuf; - void *dtb = NULL; - unsigned long initrd_load_addr = 0, dtb_len; + void *headers, *dtb = NULL; + unsigned long headers_sz, initrd_load_addr = 0, dtb_len; int ret = 0; kbuf.image = image; /* not allocate anything below the kernel */ kbuf.buf_min = kernel_load_addr + kernel_size; + /* load elf core header */ + if (image->type == KEXEC_TYPE_CRASH) { + ret = prepare_elf_headers(&headers, &headers_sz); + if (ret) { + pr_err("Preparing elf core header failed\n"); + goto out_err; + } + + kbuf.buffer = headers; + kbuf.bufsz = headers_sz; + kbuf.mem = 0; + kbuf.memsz = headers_sz; + kbuf.buf_align = SZ_64K; /* largest supported page size */ + kbuf.buf_max = ULONG_MAX; + kbuf.top_down = true; + + ret = kexec_add_buffer(&kbuf); + if (ret) { + vfree(headers); + goto out_err; + } + image->arch.elf_headers = headers; + image->arch.elf_headers_mem = kbuf.mem; + image->arch.elf_headers_sz = headers_sz; + + pr_debug("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + image->arch.elf_headers_mem, headers_sz, headers_sz); + } + /* load initrd */ if (initrd) { kbuf.buffer = initrd; -- 2.19.0 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
