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>
---
arch/arm64/include/asm/kexec.h | 4 +
arch/arm64/kernel/kexec_image.c | 9 +-
arch/arm64/kernel/machine_kexec_file.c | 114 ++++++++++++++++++++++++-
3 files changed, 124 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
index 69333694e3e2..eeb5766928b0 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 {
phys_addr_t dtb_mem;
void *dtb_buf;
+ /* Core ELF header buffer */
+ void *elf_headers;
+ unsigned long elf_headers_sz;
+ unsigned long elf_load_addr;
};
/**
diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c
index a47cf9bc699e..df1e341d3a28 100644
--- a/arch/arm64/kernel/kexec_image.c
+++ b/arch/arm64/kernel/kexec_image.c
@@ -67,8 +67,13 @@ static void *image_load(struct kimage *image,
/* Load the kernel */
kbuf.image = image;
- kbuf.buf_min = 0;
- kbuf.buf_max = ULONG_MAX;
+ if (image->type == KEXEC_TYPE_CRASH) {
+ kbuf.buf_min = crashk_res.start;
+ kbuf.buf_max = crashk_res.end + 1;
+ } else {
+ kbuf.buf_min = 0;
+ kbuf.buf_max = ULONG_MAX;
+ }
kbuf.top_down = false;
kbuf.buffer = kernel;
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index a0b44fe18b95..261564df7210 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -16,7 +16,9 @@
#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>
const struct kexec_file_ops * const kexec_file_loaders[] = {
@@ -29,6 +31,10 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
vfree(image->arch.dtb_buf);
image->arch.dtb_buf = 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);
}
@@ -38,13 +44,31 @@ static int setup_dtb(struct kimage *image,
char **dtb_buf, size_t *dtb_buf_len)
{
char *buf = NULL;
- size_t buf_size;
+ size_t buf_size, range_size;
int nodeoffset;
u64 value;
int ret;
+ /* check ranges against root's #address-cells and #size-cells */
+ if (image->type == KEXEC_TYPE_CRASH &&
+ (!of_fdt_cells_size_fitted(image->arch.elf_load_addr,
+ image->arch.elf_headers_sz) ||
+ !of_fdt_cells_size_fitted(crashk_res.start,
+ crashk_res.end - crashk_res.start + 1))) {
+ pr_err("Crash memory region doesn't fit into DT's root cell sizes.\n");
+ ret = -EINVAL;
+ goto out_err;
+ }
+
/* duplicate dt blob */
buf_size = fdt_totalsize(initial_boot_params);
+ range_size = of_fdt_reg_cells_size();
+
+ if (image->type == KEXEC_TYPE_CRASH) {
+ buf_size += fdt_prop_len("linux,elfcorehdr", range_size);
+ buf_size += fdt_prop_len("linux,usable-memory-range",
+ range_size);
+ }
if (initrd_load_addr) {
/* can be redundant, but trimmed at the end */
@@ -74,6 +98,23 @@ 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, "linux,elfcorehdr",
+ image->arch.elf_load_addr,
+ image->arch.elf_headers_sz);
+ if (ret)
+ goto out_err;
+
+ /* add linux,usable-memory-range */
+ ret = fdt_setprop_reg(buf, nodeoffset,
+ "linux,usable-memory-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, "bootargs", cmdline);
@@ -132,6 +173,45 @@ 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, 0,
+ &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, 0,
+ &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)
+ goto out;
+
+ ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
+
+out:
+ kfree(cmem);
+ return ret;
+}
+
int load_other_segments(struct kimage *image,
unsigned long kernel_load_addr,
unsigned long kernel_size,
@@ -139,11 +219,43 @@ int load_other_segments(struct kimage *image,
char *cmdline, unsigned long cmdline_len)
{
struct kexec_buf kbuf;
+ void *hdrs_addr;
+ unsigned long hdrs_sz;
unsigned long initrd_load_addr = 0;
char *dtb = NULL;
unsigned long dtb_len = 0;
int ret = 0;
+ /* load elf core header */
+ if (image->type == KEXEC_TYPE_CRASH) {
+ ret = prepare_elf_headers(&hdrs_addr, &hdrs_sz);
+ if (ret) {
+ pr_err("Preparing elf core header failed\n");
+ goto out_err;
+ }
+
+ kbuf.image = image;
+ kbuf.buffer = hdrs_addr;
+ kbuf.bufsz = hdrs_sz;
+ kbuf.memsz = hdrs_sz;
+ kbuf.buf_align = PAGE_SIZE;
+ kbuf.buf_min = crashk_res.start;
+ kbuf.buf_max = crashk_res.end + 1;
+ kbuf.top_down = true;
+
+ ret = kexec_add_buffer(&kbuf);
+ if (ret) {
+ vfree(hdrs_addr);
+ goto out_err;
+ }
+ image->arch.elf_headers = hdrs_addr;
+ image->arch.elf_headers_sz = hdrs_sz;
+ image->arch.elf_load_addr = kbuf.mem;
+
+ pr_debug("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
+ image->arch.elf_load_addr, hdrs_sz, hdrs_sz);
+ }
+
kbuf.image = image;
/* not allocate anything below the kernel */
kbuf.buf_min = kernel_load_addr + kernel_size;
--
2.17.0
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