[PATCH v12 09/15] arm64: kexec_file: Use crash_prepare_headers() helper to simplify code

Jinjie Ruan
2026-04-02T07:26:58Z

Use the newly introduced crash_prepare_headers() function to replace
the existing prepare_elf_headers(), allocate cmem and exclude crash
kernel memory in the crash core, which reduce code duplication.

Only the following two architecture functions need to be implemented:
- arch_get_system_nr_ranges(). Use for_each_mem_range() to traverse
and pre-count the max number of memory ranges.

- arch_crash_populate_cmem(). Use for_each_mem_range to traverse
and collect the memory ranges and fills them into cmem.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/arm64/kernel/machine_kexec_file.c | 46 ++++++++------------------
1 file changed, 14 insertions(+), 32 deletions(-)

diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index df52ac4474c9..558408f403b5 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -40,51 +40,33 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
}

#ifdef CONFIG_CRASH_DUMP
-static int prepare_elf_headers(void **addr, unsigned long *sz)
+unsigned int arch_get_system_nr_ranges(void)
{
- struct crash_mem *cmem;
- unsigned int nr_ranges;
- int ret;
- u64 i;
+ unsigned int nr_ranges = 2; /* for exclusion of crashkernel region */
phys_addr_t start, end;
+ u64 i;

- nr_ranges = 2; /* for exclusion of crashkernel region */
for_each_mem_range(i, &start, &end)
nr_ranges++;

- cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
- if (!cmem)
- return -ENOMEM;
+ return nr_ranges;
+}
+
+int arch_crash_populate_cmem(struct crash_mem *cmem)
+{
+ phys_addr_t start, end;
+ u64 i;

- cmem->max_nr_ranges = nr_ranges;
- cmem->nr_ranges = 0;
for_each_mem_range(i, &start, &end) {
- if (cmem->nr_ranges >= cmem->max_nr_ranges) {
- ret = -ENOMEM;
- goto out;
- }
+ if (cmem->nr_ranges >= cmem->max_nr_ranges)
+ return -ENOMEM;

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;
-
- if (crashk_low_res.end) {
- ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
- if (ret)
- goto out;
- }
-
- ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
-
-out:
- kfree(cmem);
- return ret;
+ return 0;
}
#endif

@@ -114,7 +96,7 @@ int load_other_segments(struct kimage *image,
void *headers;
unsigned long headers_sz;
if (image->type == KEXEC_TYPE_CRASH) {
- ret = prepare_elf_headers(&headers, &headers_sz);
+ ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
if (ret) {
pr_err("Preparing elf core header failed\n");
goto out_err;
--
2.34.1