Hi Dave,
Ken'ichi Ohmichi wrote:
>>>> Is there a reason that makedumpfile does not fill in the utsname structure
>>>> in the compressed dumpfile's header?
>>> Thank you for good point.
>>>
>>> makedumpfile does not fill it because makedumpfile might not be able to
>>> get kernel debug information (containing symbol system_utsname/init_uts_ns).
>>> makedumpfile does not need kernel debug information if dump_level is 0 or 1,
>>> and it does not read a new_utsname structure. (check_release() is not called.)
>>>
>>>
>>>> The data structure does get read into a local new_utsname structure in the
>>>> check_release() function, but it doesn't get saved and copied into the
>>>> disk_dump_header in write_kdump_header().
>>>>
>>>> It would be helpful if that were in place as a quick ID for what the
>>>> compressed dumpfile contains.
>>> I feel that is worth.
>>> How about saving new_utsname data into disk_dump_header only if dump_level
>>> is 2 or bigger ?
>> Well, that's certainly preferable than the way it is now.
>>
>> But let me ask you this...
>>
>> Given that the init_uts_ns structure is always located in:
>>
>> (1) unity-mapped memory, or in a mapped kernel region for x86_64/ia64, and
>> (2) that your initial() function calls get_phys_base() in all cases,
>>
>> can't you just strip the relevant unity-mapping from the supplied
>> VMCOREINFO/init_uts_ns symbol value, apply the phys_base, and then
>> read it from the vmcore file?
>
> Thank you for the comment.
> We can do it by the attached patch.
I forgot to say.
I will take a vacation since tomorrow, and I'll reply to you after 7 May.
Thanks
Ken'ichi Ohmichi
> ---
> [PATCH] Save utsname data into disk_dump_header.
>
> By this patch, makedumpfile saves utsname data into disk_dump_header.
> The crash utility can output the data by 'help -n' command:
>
> crash> help -n
> diskdump_data:
> flags: 6 (KDUMP_CMPRS_LOCAL|ERROR_EXCLUDED)
> dfd: 3
> ofp: 3b29b4d760
> machine_type: 62 (EM_X86_64)
>
> header: c34c70
> signature: "KDUMP "
> header_version: 2
> utsname:
> sysname: Linux
> nodename: localhost.localdomain
> release: 2.6.29-rc7
> version: #1 SMP Mon Mar 9 11:20:46 JST 2009
> machine: x86_64
> domainname: (none)
> timestamp:
> [snip]
>
> Signed-off-by: Ken'ichi Ohmichi <oomichi@xxxxxxxxxxxxxxxxx>
> ---
> diff -puN a/makedumpfile.c b/makedumpfile.c
> --- a/makedumpfile.c 2009-04-20 15:26:23.000000000 +0900
> +++ b/makedumpfile.c 2009-04-21 12:48:00.000000000 +0900
> @@ -382,9 +382,8 @@ fallback_to_current_page_size(void)
> }
>
> int
> -check_release(void)
> +get_utsname(struct utsname *system_utsname)
> {
> - struct utsname system_utsname;
> unsigned long utsname;
>
> /*
> @@ -398,13 +397,18 @@ check_release(void)
> ERRMSG("Can't get the symbol of system_utsname.\n");
> return FALSE;
> }
> - if (!readmem(VADDR, utsname, &system_utsname, sizeof(struct utsname))){
> + if (!readmem(VADDR, utsname, system_utsname, sizeof(struct utsname))){
> ERRMSG("Can't get the address of system_utsname.\n");
> return FALSE;
> }
> + return TRUE;
> +}
>
> +int
> +check_release(void)
> +{
> if (info->flag_read_vmcoreinfo) {
> - if (strcmp(system_utsname.release, info->release)) {
> + if (strcmp(info->system_utsname.release, info->release)) {
> ERRMSG("%s and %s don't match.\n",
> info->name_vmcoreinfo, info->name_memory);
> retcd = WRONG_RELEASE;
> @@ -412,7 +416,7 @@ check_release(void)
> }
> }
>
> - info->kernel_version = get_kernel_version(system_utsname.release);
> + info->kernel_version = get_kernel_version(info->system_utsname.release);
> if (info->kernel_version == FALSE) {
> if (!info->flag_read_vmcoreinfo)
> ERRMSG("Or %s and %s don't match.\n",
> @@ -3378,7 +3382,7 @@ get_mem_map(void)
> int
> initial(void)
> {
> - int flag_need_debuginfo;
> + int flag_get_debuginfo = FALSE, flag_need_debuginfo = FALSE;
>
> if (!(vt.mem_flags & MEMORY_XEN) && info->flag_exclude_xen_dom) {
> MSG("'-X' option is disable,");
> @@ -3398,6 +3402,7 @@ initial(void)
> if (!read_vmcoreinfo())
> return FALSE;
> close_vmcoreinfo();
> + flag_get_debuginfo = TRUE;
> /*
> * Get the debug information for analysis from the kernel file
> */
> @@ -3413,6 +3418,7 @@ initial(void)
>
> if (!get_srcfile_info())
> return FALSE;
> + flag_get_debuginfo = TRUE;
> } else {
> /*
> * Check whether /proc/vmcore contains vmcoreinfo,
> @@ -3438,6 +3444,7 @@ initial(void)
> if (!read_vmcoreinfo_from_vmcore(info->offset_vmcoreinfo,
> info->size_vmcoreinfo, FALSE))
> return FALSE;
> + flag_get_debuginfo = TRUE;
> }
>
> if (!get_value_for_old_linux())
> @@ -3454,6 +3461,12 @@ out:
> if (!get_max_mapnr())
> return FALSE;
>
> + if (flag_get_debuginfo) {
> + if (!get_machdep_info())
> + return FALSE;
> + if (!get_utsname(&info->system_utsname))
> + return FALSE;
> + }
> if ((info->max_dump_level <= DL_EXCLUDE_ZERO) && !info->flag_dmesg)
> flag_need_debuginfo = FALSE;
> else
> @@ -3465,10 +3478,6 @@ out:
> else
> return TRUE;
> }
> -
> - if (!get_machdep_info())
> - return FALSE;
> -
> if (!check_release())
> return FALSE;
>
> @@ -4969,6 +4978,7 @@ write_kdump_header(void)
> dh->bitmap_blocks
> = divideup(info->len_bitmap, dh->block_size);
> memcpy(&dh->timestamp, &info->timestamp, sizeof(dh->timestamp));
> + memcpy(&dh->utsname, &info->system_utsname, sizeof(dh->utsname));
>
> size = sizeof(struct disk_dump_header);
> if (!write_buffer(info->fd_dumpfile, 0, dh, size, info->name_dumpfile))
> diff -puN a/makedumpfile.h b/makedumpfile.h
> --- a/makedumpfile.h 2009-04-20 15:26:23.000000000 +0900
> +++ b/makedumpfile.h 2009-04-21 12:47:58.000000000 +0900
> @@ -750,6 +750,7 @@ struct splitting_info {
> struct DumpInfo {
> int32_t kernel_version; /* version of first kernel*/
> struct timeval timestamp;
> + struct utsname system_utsname;
>
> /*
> * General info:
>
> --
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