[PATCH] makedumpfile: ppc64: get vmalloc start address from vmcoreinfo
HAGIO KAZUHITO(萩尾 一仁)
k-hagio-ab at nec.com
Mon Mar 18 01:48:34 PDT 2024
On 2024/03/18 17:26, Aditya Gupta wrote:
> Hi,
> The commit removing 'vmap_area_list' is now merged in Linux mainline tree.
> commit: 55c49fee57af99f3c663e69dedc5b85e691bbe50
> mm/vmalloc: remove vmap_area_list
Applied with this commit id and the fix.
https://github.com/makedumpfile/makedumpfile/commit/94241fd2feed059227a243618f2acc6aabf366e8
Thanks,
Kazu
>
> Any comments on this patch ?
>
> Thanks,
>
> Aditya Gupta
>
> On 24/02/24 00:33, Aditya Gupta wrote:
>> Below error was noticed when running makedumpfile on linux-next kernel
>> crash (linux-next tag next-20240121):
>>
>> ...
>> Checking for memory holes : [100.0 %] | readpage_elf: Attempt to
>> read non-existent page at 0xc000000000000.
>> [ 17.551718] kdump.sh[404]: readmem: type_addr: 0,
>> addr:c00c000000000000, size:16384
>> [ 17.551793] kdump.sh[404]: __exclude_unnecessary_pages: Can't
>> read the buffer of struct page.
>> [ 17.551864] kdump.sh[404]: create_2nd_bitmap: Can't exclude
>> unnecessary pages.
>> [ 17.562632] kdump.sh[404]: The kernel version is not supported.
>> [ 17.562708] kdump.sh[404]: The makedumpfile operation may be
>> incomplete.
>> [ 17.562773] kdump.sh[404]: makedumpfile Failed.
>> [ 17.564335] kdump[406]: saving vmcore failed, _exitcode:1
>>
>> Above error was due to 'vmap_area_list' and 'vmlist' symbols missing
>> from the vmcore.
>>
>> 'vmap_area_list' was removed in the linux kernel with below commit:
>>
>> commit 378eb24a0658dd922b29524e0ce35c6c43f56cba
>> mm/vmalloc: remove vmap_area_list
>>
>> Subsequently the commit also introduced 'VMALLOC_START' in vmcoreinfo to
>> get base address of vmalloc area, instead of depending on
>> 'vmap_area_list'
>>
>> Hence if 'VMALLOC_START' symbol is there in vmcoreinfo:
>> 1. Set vmalloc_start based on 'VMALLOC_START'
>> 2. Don't error if vmap_area_list/vmlist are not defined
>>
>> Reported-by: Sachin Sant <sachinp at linux.ibm.com>
>> Signed-off-by: Aditya Gupta <adityag at linux.ibm.com>
>> ---
>> arch/ppc64.c | 19 +++++++++++++------
>> makedumpfile.c | 3 ++-
>> makedumpfile.h | 6 +++---
>> 3 files changed, 18 insertions(+), 10 deletions(-)
>>
>> diff --git a/arch/ppc64.c b/arch/ppc64.c
>> index 96c357cb0335..bb62e2cd199a 100644
>> --- a/arch/ppc64.c
>> +++ b/arch/ppc64.c
>> @@ -568,7 +568,9 @@ get_machdep_info_ppc64(void)
>> /*
>> * Get vmalloc_start value from either vmap_area_list or vmlist.
>> */
>> - if ((SYMBOL(vmap_area_list) != NOT_FOUND_SYMBOL)
>> + if (NUMBER(vmalloc_start) != NOT_FOUND_SYMBOL) {
>> + vmalloc_start = NUMBER(vmalloc_start);
>> + } else if ((SYMBOL(vmap_area_list) != NOT_FOUND_SYMBOL)
>> && (OFFSET(vmap_area.va_start) != NOT_FOUND_STRUCTURE)
>> && (OFFSET(vmap_area.list) != NOT_FOUND_STRUCTURE)) {
>> if (!readmem(VADDR, SYMBOL(vmap_area_list) +
>> OFFSET(list_head.next),
>> @@ -684,11 +686,16 @@ vaddr_to_paddr_ppc64(unsigned long vaddr)
>> if ((SYMBOL(vmap_area_list) == NOT_FOUND_SYMBOL)
>> || (OFFSET(vmap_area.va_start) == NOT_FOUND_STRUCTURE)
>> || (OFFSET(vmap_area.list) == NOT_FOUND_STRUCTURE)) {
>> - if ((SYMBOL(vmlist) == NOT_FOUND_SYMBOL)
>> - || (OFFSET(vm_struct.addr) == NOT_FOUND_STRUCTURE)) {
>> - ERRMSG("Can't get info for vmalloc translation.\n");
>> - return NOT_PADDR;
>> - }
>> + /*
>> + * Don't depend on vmap_area_list/vmlist if vmalloc_start is
>> set in
>> + * vmcoreinfo, in that case proceed without error
>> + */
>> + if (NUMBER(vmalloc_start) == NOT_FOUND_NUMBER)
>> + if ((SYMBOL(vmlist) == NOT_FOUND_SYMBOL)
>> + || (OFFSET(vm_struct.addr) == NOT_FOUND_STRUCTURE)) {
>> + ERRMSG("Can't get info for vmalloc translation.\n");
>> + return NOT_PADDR;
>> + }
>> }
>> return ppc64_vtop_level4(vaddr);
>> diff --git a/makedumpfile.c b/makedumpfile.c
>> index b004b93fecb7..b6c63fad15f3 100644
>> --- a/makedumpfile.c
>> +++ b/makedumpfile.c
>> @@ -2978,6 +2978,8 @@ read_vmcoreinfo(void)
>> READ_NUMBER("PAGE_OFFLINE_MAPCOUNT_VALUE",
>> PAGE_OFFLINE_MAPCOUNT_VALUE);
>> READ_NUMBER("phys_base", phys_base);
>> READ_NUMBER("KERNEL_IMAGE_SIZE", KERNEL_IMAGE_SIZE);
>> +
>> + READ_NUMBER_UNSIGNED("VMALLOC_START", vmalloc_start);
>> #ifdef __aarch64__
>> READ_NUMBER("VA_BITS", VA_BITS);
>> READ_NUMBER("TCR_EL1_T1SZ", TCR_EL1_T1SZ);
>> @@ -2989,7 +2991,6 @@ read_vmcoreinfo(void)
>> READ_NUMBER("VA_BITS", va_bits);
>> READ_NUMBER_UNSIGNED("phys_ram_base", phys_ram_base);
>> READ_NUMBER_UNSIGNED("PAGE_OFFSET", page_offset);
>> - READ_NUMBER_UNSIGNED("VMALLOC_START", vmalloc_start);
>> READ_NUMBER_UNSIGNED("VMALLOC_END", vmalloc_end);
>> READ_NUMBER_UNSIGNED("VMEMMAP_START", vmemmap_start);
>> READ_NUMBER_UNSIGNED("VMEMMAP_END", vmemmap_end);
>> diff --git a/makedumpfile.h b/makedumpfile.h
>> index 59c83e1d9df3..4021c5af2a34 100644
>> --- a/makedumpfile.h
>> +++ b/makedumpfile.h
>> @@ -541,8 +541,6 @@ do { \
>> * The value of dependence on machine
>> */
>> #define PAGE_OFFSET (info->page_offset)
>> -#define VMALLOC_START (info->vmalloc_start)
>> -#define VMALLOC_END (info->vmalloc_end)
>> #define VMEMMAP_START (info->vmemmap_start)
>> #define VMEMMAP_END (info->vmemmap_end)
>> #define PMASK (0x7ffffffffffff000UL)
>> @@ -2262,6 +2260,9 @@ struct number_table {
>> long HUGETLB_PAGE_DTOR;
>> long phys_base;
>> long KERNEL_IMAGE_SIZE;
>> +
>> + unsigned long vmalloc_start;
>> +
>> #ifdef __aarch64__
>> long VA_BITS;
>> long TCR_EL1_T1SZ;
>> @@ -2272,7 +2273,6 @@ struct number_table {
>> long va_bits;
>> unsigned long phys_ram_base;
>> unsigned long page_offset;
>> - unsigned long vmalloc_start;
>> unsigned long vmalloc_end;
>> unsigned long vmemmap_start;
>> unsigned long vmemmap_end;
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