Re: [PATCH v7 3/5] crash: Use crash_exclude_core_ranges() on powerpc

Jinjie Ruan
2026-02-28T01:22:03Z

On 2026/2/27 22:50, Sourabh Jain wrote:
> Resend of:
> https://lore.kernel.org/all/19cf18b5-362d-4ff2-8b85-e2e72809250c@linux.ibm.com/
>
> On 26/02/26 18:34, 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/kexec/ranges.c | 16 ++++------------
>>   include/linux/crash_core.h  |  4 ++++
>>   kernel/crash_core.c         | 19 +++++++++++++------
>>   3 files changed, 21 insertions(+), 18 deletions(-)
>>
>> 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)
>
>
> update_crash_elfcorehdr() in arch/powerpc/kexec/crash.c still calls
> crash_exclude_mem_range_guarded(), causing a build failure.
>
> ld: arch/powerpc/kexec/crash.o: in function `update_crash_elfcorehdr':
> /root/linux/arch/powerpc/kexec/crash.c:454: undefined reference to
> `crash_exclude_mem_range_guarded'
>
>
> To fix this:
> --------------
> 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;
>
> With the above change included, things are working fine on powerpc.

It seems the declaration of crash_exclude_mem_range_guarded() added in
arch/powerpc/include/asm/kexec_ranges.h can also be removed.

>
>
>>   {
>>       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;
>>
>