Re: [PATCH v8 3/5] crash: Use crash_exclude_core_ranges() on powerpc

Sourabh Jain
2026-03-02T06:00:14Z

Changes look good to me.
I tested this on LPAR and QEMU, and dump capture works fine with these
changes.
I even tried reserving kdump memory using crashkernel=xxM,cma.

Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>

On 02/03/26 09:23, Jinjie Ruan wrote:
> The crash memory exclude of crashk_res and crashk_cma memory on powerpc
> are almost identical to the generic crash_exclude_core_ranges().
>
> By introducing the architecture-specific arch_crash_exclude_mem_range()
> function with a default implementation of crash_exclude_mem_range(),
> and using crash_exclude_mem_range_guarded as powerpc's separate
> implementation, the generic crash_exclude_core_ranges() helper function
> can be reused.
>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
> arch/powerpc/include/asm/kexec_ranges.h | 3 ---
> arch/powerpc/kexec/crash.c | 2 +-
> arch/powerpc/kexec/ranges.c | 16 ++++------------
> include/linux/crash_core.h | 4 ++++
> kernel/crash_core.c | 19 +++++++++++++------
> 5 files changed, 22 insertions(+), 22 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/kexec_ranges.h b/arch/powerpc/include/asm/kexec_ranges.h
> index ad95e3792d10..8489e844b447 100644
> --- a/arch/powerpc/include/asm/kexec_ranges.h
> +++ b/arch/powerpc/include/asm/kexec_ranges.h
> @@ -7,9 +7,6 @@
> void sort_memory_ranges(struct crash_mem *mrngs, bool merge);
> struct crash_mem *realloc_mem_ranges(struct crash_mem **mem_ranges);
> int add_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size);
> -int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
> - unsigned long long mstart,
> - unsigned long long mend);
> int get_exclude_memory_ranges(struct crash_mem **mem_ranges);
> int get_reserved_memory_ranges(struct crash_mem **mem_ranges);
> int get_crash_memory_ranges(struct crash_mem **mem_ranges);
> diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
> index 898742a5205c..e59e909c369d 100644
> --- a/arch/powerpc/kexec/crash.c
> +++ b/arch/powerpc/kexec/crash.c
> @@ -451,7 +451,7 @@ static void update_crash_elfcorehdr(struct kimage *image, struct memory_notify *
> base_addr = PFN_PHYS(mn->start_pfn);
> size = mn->nr_pages * PAGE_SIZE;
> end = base_addr + size - 1;
> - ret = crash_exclude_mem_range_guarded(&cmem, base_addr, end);
> + ret = arch_crash_exclude_mem_range(&cmem, base_addr, end);
> if (ret) {
> pr_err("Failed to remove hot-unplugged memory from crash memory ranges\n");
> goto out;
> diff --git a/arch/powerpc/kexec/ranges.c b/arch/powerpc/kexec/ranges.c
> index 6c58bcc3e130..e5fea23b191b 100644
> --- a/arch/powerpc/kexec/ranges.c
> +++ b/arch/powerpc/kexec/ranges.c
> @@ -553,9 +553,9 @@ int get_usable_memory_ranges(struct crash_mem **mem_ranges)
> #endif /* CONFIG_KEXEC_FILE */
>
> #ifdef CONFIG_CRASH_DUMP
> -int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
> - unsigned long long mstart,
> - unsigned long long mend)
> +int arch_crash_exclude_mem_range(struct crash_mem **mem_ranges,
> + unsigned long long mstart,
> + unsigned long long mend)
> {
> struct crash_mem *tmem = *mem_ranges;
>
> @@ -604,18 +604,10 @@ int get_crash_memory_ranges(struct crash_mem **mem_ranges)
> sort_memory_ranges(*mem_ranges, true);
> }
>
> - /* Exclude crashkernel region */
> - ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_res.start, crashk_res.end);
> + ret = crash_exclude_core_ranges(mem_ranges);
> if (ret)
> goto out;
>
> - for (i = 0; i < crashk_cma_cnt; ++i) {
> - ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_cma_ranges[i].start,
> - crashk_cma_ranges[i].end);
> - if (ret)
> - goto out;
> - }
> -
> /*
> * FIXME: For now, stay in parity with kexec-tools but if RTAS/OPAL
> * regions are exported to save their context at the time of
> diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
> index 033b20204aca..dbec826dc53b 100644
> --- a/include/linux/crash_core.h
> +++ b/include/linux/crash_core.h
> @@ -68,6 +68,7 @@ extern int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_ma
> void **addr, unsigned long *sz);
> extern int crash_prepare_headers(int need_kernel_map, void **addr,
> unsigned long *sz, unsigned long *nr_mem_ranges);
> +extern int crash_exclude_core_ranges(struct crash_mem **cmem);
>
> struct kimage;
> struct kexec_segment;
> @@ -88,6 +89,9 @@ extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
> extern unsigned int arch_get_system_nr_ranges(void);
> extern int arch_crash_populate_cmem(struct crash_mem *cmem);
> extern int arch_crash_exclude_ranges(struct crash_mem *cmem);
> +extern int arch_crash_exclude_mem_range(struct crash_mem **mem,
> + unsigned long long mstart,
> + unsigned long long mend);
>
> #else /* !CONFIG_CRASH_DUMP*/
> struct pt_regs;
> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> index 96a96e511f5a..300d44ad5471 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -287,24 +287,31 @@ unsigned int __weak arch_get_system_nr_ranges(void) { return 0; }
> int __weak arch_crash_populate_cmem(struct crash_mem *cmem) { return -1; }
> int __weak arch_crash_exclude_ranges(struct crash_mem *cmem) { return 0; }
>
> -static int crash_exclude_core_ranges(struct crash_mem *cmem)
> +int __weak arch_crash_exclude_mem_range(struct crash_mem **mem,
> + unsigned long long mstart,
> + unsigned long long mend)
> +{
> + return crash_exclude_mem_range(*mem, mstart, mend);
> +}
> +
> +int crash_exclude_core_ranges(struct crash_mem **cmem)
> {
> int ret, i;
>
> /* Exclude crashkernel region */
> - ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> + ret = arch_crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> if (ret)
> return ret;
>
> if (crashk_low_res.end) {
> - ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> + ret = arch_crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> if (ret)
> return ret;
> }
>
> for (i = 0; i < crashk_cma_cnt; ++i) {
> - ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
> - crashk_cma_ranges[i].end);
> + ret = arch_crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
> + crashk_cma_ranges[i].end);
> if (ret)
> return ret;
> }
> @@ -331,7 +338,7 @@ int crash_prepare_headers(int need_kernel_map, void **addr, unsigned long *sz,
> if (ret)
> goto out;
>
> - ret = crash_exclude_core_ranges(cmem);
> + ret = crash_exclude_core_ranges(&cmem);
> if (ret)
> goto out;