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 <takahiro.akashi@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Reviewed-by: James Morse <james.morse@xxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Frank Rowand <frowand.list@xxxxxxxxx>
Cc: devicetree@xxxxxxxxxxxxxxx
---
arch/arm64/include/asm/kexec.h | 4 +
arch/arm64/kernel/machine_kexec_file.c | 109 ++++++++++++++++++++++++-
2 files changed, 110 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
index 5e673481b3a3..1b2c27026ae0 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;
};
/**
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index 05fb2d4e6fef..4b5ea256c84c 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -16,10 +16,14 @@
#include <linux/libfdt.h>
#include <linux/memblock.h>
#include <linux/of_fdt.h>
+#include <linux/slab.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"
@@ -34,6 +38,10 @@ 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);
}
@@ -43,12 +51,25 @@ static int setup_dtb(struct kimage *image,
void **dtb_buf, unsigned long *dtb_buf_len)
{
void *buf = NULL;
- size_t buf_size;
+ int addr_cells, size_cells;
+ size_t buf_size, range_size;
int nodeoffset;
int ret;
/* duplicate dt blob */
buf_size = fdt_totalsize(initial_boot_params);
+ addr_cells = fdt_address_cells(initial_boot_params, 0);
+ if (addr_cells < 0)
+ return -EINVAL;
+ size_cells = fdt_size_cells(initial_boot_params, 0);
+ if (size_cells < 0)
+ return -EINVAL;
+ range_size = (addr_cells + size_cells) * sizeof(u32);
+
+ if (image->type == KEXEC_TYPE_CRASH) {
+ buf_size += fdt_prop_len(FDT_PSTR_KEXEC_ELFHDR, range_size);
+ buf_size += fdt_prop_len(FDT_PSTR_MEM_RANGE, range_size);
+ }
if (initrd_load_addr) {
/* can be redundant, but trimmed at the end */
@@ -78,6 +99,22 @@ static int setup_dtb(struct kimage *image,
goto out_err;
}
+ if (image->type == KEXEC_TYPE_CRASH) {
+ /* add linux,elfcorehdr */
+ ret = fdt_setprop_reg(buf, nodeoffset, FDT_PSTR_KEXEC_ELFHDR,
+ image->arch.elf_headers_mem,
+ image->arch.elf_headers_sz);
+ if (ret)
+ goto out_err;
+
+ /* add linux,usable-memory-range */
+ ret = fdt_setprop_reg(buf, nodeoffset, FDT_PSTR_MEM_RANGE,
+ crashk_res.start,
+ crashk_res.end - crashk_res.start + 1);
+ if (ret)
+ goto out_err;
+ }
+
/* add bootargs */
if (cmdline) {
ret = fdt_setprop_string(buf, nodeoffset, FDT_PSTR_BOOTARGS,
@@ -135,6 +172,43 @@ static int setup_dtb(struct kimage *image,
return ret;
}
+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,
@@ -142,14 +216,43 @@ int load_other_segments(struct kimage *image,
char *cmdline, unsigned long cmdline_len)
{
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
