* [PATCH] makedumpfile: Add description of incomplete dump file
@ 2014-11-12 8:29 Zhou Wenjian
2014-11-13 9:01 ` Atsushi Kumagai
0 siblings, 1 reply; 4+ messages in thread
From: Zhou Wenjian @ 2014-11-12 8:29 UTC (permalink / raw)
To: kexec
Add description of incomplete elf and kdump-compressed dump file
in IMPLEMENTATION.
Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
---
IMPLEMENTATION | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 76 insertions(+), 0 deletions(-)
diff --git a/IMPLEMENTATION b/IMPLEMENTATION
index 2f4cfd6..8f8a945 100644
--- a/IMPLEMENTATION
+++ b/IMPLEMENTATION
@@ -112,3 +112,79 @@
unsigned long long page_flags; /* page flags */
} page_desc_t;
+* The incomplete DUMPFILE
+ When generating DUMPFILE, if ENOSPACE error happens, the DUMPFILE will be
+ incomplete.
+
+ - The incomplete kdump-compressed DUMPFILE
+
+ the complete the incomplete
+ +-----------------------+ +-----------------------+
+ | main header | | main header | have incomplete flag
+ |-----------------------+ |-----------------------+
+ | sub header | | sub header |
+ |-----------------------+ |-----------------------+
+ | 1st-bitmap | | 1st-bitmap |
+ |-----------------------+ |-----------------------+
+ | 2nd-bitmap | | 2nd-bitmap |
+ |-----------------------+ |-----------------------+
+ | page header for pfn 0 | | page header for pfn 0 |
+ | page header for pfn 1 | | page header for pfn 1 |
+ | : | | : |
+ | page header for pfn N | | page header for pfn N | The page headers after
+ | : | | | N don't exist. The
+ | page header for pfn Z | | | value of it is zero,
+ |-----------------------| |-----------------------| when try to read it.
+ | page data (pfn 0) | | page data (pfn 0) |
+ | page data (pfn 1) | | page data (pfn 1) |
+ | : | | : |
+ | page data (pfn N) | | page data (pfn N) |
+ | : | +-----------------------+
+ | page data (pfn Z) |
+ +-----------------------+
+
+ The incomplete flag is set into status of disk_dump_header by
+ status |= DUMP_DH_COMPRESSED_INCOMPLETE
+ DUMP_DH_COMPRESSED_INCOMPLETE : 0x8
+
+ The page header and page data are written in pairs. When writting page data
+ (pfn N+1), if ENOSPACE error happens, the page headers after N won't be
+ written either.
+
+ If there is no page data dumped into the DUMPFILE, the DUMPFILE can't be
+ analysed by crash.
+
+ - The incomplete elf DUMPFILE
+
+ the complete the incomplete
+ +-------------+ +-------------+
+ | elf header | | elf header | have incomplete flag
+ |-------------+ |-------------+
+ | PT_NOTE | | PT_NOTE |
+ | PT_LOAD(1) | | PT_LOAD(1) |
+ | : | | : |
+ | PT_LOAD(N) | | PT_LOAD(N) | The PT_LOAD after N don't exist.
+ | : | | | The value of it is zero, when try
+ | PT_LOAD(Z) | | | to read it.
+ |-------------+ |-------------+
+ | sec_hdr | | sec_hdr |
+ |-------------+ |-------------+
+ | elf note | | elf note |
+ |-------------+ |-------------+
+ | segment(1) | | segment(1) |
+ | : | | : |
+ | segment(N) | | segment(N) | The segment(N) is incomplete.
+ | : | +-------------+ The segments after N don't exist.
+ | segment(Z) |
+ +-------------+
+
+ The incomplete flag is set into e_flags of elf_header by
+ e_flags |= DUMP_ELF_INCOMPLETE
+ DUMP_ELF_INCOMPLETE : 0x1
+
+ The PT_LOAD and segment are written in pairs. When writting segment(N)
+ , if ENOSPACE error happens, the PT_LOAD after N won't be written
+ either.
+
+ If there is no segment dumped into the DUMPFILE, the DUMPFILE can't be
+ analysed by crash.
--
1.7.1
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply related [flat|nested] 4+ messages in thread
* RE: [PATCH] makedumpfile: Add description of incomplete dump file
2014-11-12 8:29 [PATCH] makedumpfile: Add description of incomplete dump file Zhou Wenjian
@ 2014-11-13 9:01 ` Atsushi Kumagai
2014-11-13 9:29 ` "Zhou, Wenjian/周文剑"
0 siblings, 1 reply; 4+ messages in thread
From: Atsushi Kumagai @ 2014-11-13 9:01 UTC (permalink / raw)
To: zhouwj-fnst@cn.fujitsu.com; +Cc: kexec@lists.infradead.org
Hello Zhou,
>Add description of incomplete elf and kdump-compressed dump file
>in IMPLEMENTATION.
That's a good idea, thanks Zhou.
I have some comments.
>Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
>Signed-off-by: Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com>
>---
> IMPLEMENTATION | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 76 insertions(+), 0 deletions(-)
>
>diff --git a/IMPLEMENTATION b/IMPLEMENTATION
>index 2f4cfd6..8f8a945 100644
>--- a/IMPLEMENTATION
>+++ b/IMPLEMENTATION
>@@ -112,3 +112,79 @@
> unsigned long long page_flags; /* page flags */
> } page_desc_t;
>
>+* The incomplete DUMPFILE
>+ When generating DUMPFILE, if ENOSPACE error happens, the DUMPFILE will be
>+ incomplete.
>+
>+ - The incomplete kdump-compressed DUMPFILE
>+
>+ the complete the incomplete
>+ +-----------------------+ +-----------------------+
>+ | main header | | main header | have incomplete flag
>+ |-----------------------+ |-----------------------+
>+ | sub header | | sub header |
>+ |-----------------------+ |-----------------------+
>+ | 1st-bitmap | | 1st-bitmap |
>+ |-----------------------+ |-----------------------+
>+ | 2nd-bitmap | | 2nd-bitmap |
>+ |-----------------------+ |-----------------------+
>+ | page header for pfn 0 | | page header for pfn 0 |
>+ | page header for pfn 1 | | page header for pfn 1 |
>+ | : | | : |
>+ | page header for pfn N | | page header for pfn N | The page headers after
>+ | : | | | N don't exist. The
>+ | page header for pfn Z | | | value of it is zero,
>+ |-----------------------| |-----------------------| when try to read it.
>+ | page data (pfn 0) | | page data (pfn 0) |
>+ | page data (pfn 1) | | page data (pfn 1) |
>+ | : | | : |
>+ | page data (pfn N) | | page data (pfn N) |
>+ | : | +-----------------------+
>+ | page data (pfn Z) |
>+ +-----------------------+
>+
>+ The incomplete flag is set into status of disk_dump_header by
>+ status |= DUMP_DH_COMPRESSED_INCOMPLETE
>+ DUMP_DH_COMPRESSED_INCOMPLETE : 0x8
>+
>+ The page header and page data are written in pairs. When writting page data
s/writting/writing/
>+ (pfn N+1), if ENOSPACE error happens, the page headers after N won't be
>+ written either.
>+
>+ If there is no page data dumped into the DUMPFILE, the DUMPFILE can't be
>+ analysed by crash.
>+
>+ - The incomplete elf DUMPFILE
There is no description of the ELF format itself in this documentation
unlike the kdump-compressed format, I would be glad if you could write it.
>+
>+ the complete the incomplete
>+ +-------------+ +-------------+
>+ | elf header | | elf header | have incomplete flag
>+ |-------------+ |-------------+
>+ | PT_NOTE | | PT_NOTE |
>+ | PT_LOAD(1) | | PT_LOAD(1) |
>+ | : | | : |
>+ | PT_LOAD(N) | | PT_LOAD(N) | The PT_LOAD after N don't exist.
>+ | : | | | The value of it is zero, when try
>+ | PT_LOAD(Z) | | | to read it.
>+ |-------------+ |-------------+
The whole program header must exist since reserve_diskspace()
pre-allocates enough space for it, the description above isn't right.
>+ | sec_hdr | | sec_hdr |
>+ |-------------+ |-------------+
>+ | elf note | | elf note |
>+ |-------------+ |-------------+
>+ | segment(1) | | segment(1) |
>+ | : | | : |
>+ | segment(N) | | segment(N) | The segment(N) is incomplete.
>+ | : | +-------------+ The segments after N don't exist.
>+ | segment(Z) |
>+ +-------------+
>+
>+ The incomplete flag is set into e_flags of elf_header by
>+ e_flags |= DUMP_ELF_INCOMPLETE
>+ DUMP_ELF_INCOMPLETE : 0x1
>+
>+ The PT_LOAD and segment are written in pairs. When writting segment(N)
s/writting/writing/
Thanks,
Atsushi Kumagai
>+ , if ENOSPACE error happens, the PT_LOAD after N won't be written
>+ either.
>+
>+ If there is no segment dumped into the DUMPFILE, the DUMPFILE can't be
>+ analysed by crash.
>--
>1.7.1
>
>
>_______________________________________________
>kexec mailing list
>kexec@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/kexec
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] makedumpfile: Add description of incomplete dump file
2014-11-13 9:01 ` Atsushi Kumagai
@ 2014-11-13 9:29 ` "Zhou, Wenjian/周文剑"
2014-11-14 1:21 ` Atsushi Kumagai
0 siblings, 1 reply; 4+ messages in thread
From: "Zhou, Wenjian/周文剑" @ 2014-11-13 9:29 UTC (permalink / raw)
To: Atsushi Kumagai; +Cc: kexec@lists.infradead.org
On 11/13/2014 05:01 PM, Atsushi Kumagai wrote:
> Hello Zhou,
>
>> Add description of incomplete elf and kdump-compressed dump file
>> in IMPLEMENTATION.
>
> That's a good idea, thanks Zhou.
> I have some comments.
>
>> Signed-off-by: Qiao Nuohan<qiaonuohan@cn.fujitsu.com>
>> Signed-off-by: Zhou Wenjian<zhouwj-fnst@cn.fujitsu.com>
>> ---
>> IMPLEMENTATION | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>> 1 files changed, 76 insertions(+), 0 deletions(-)
>>
>> diff --git a/IMPLEMENTATION b/IMPLEMENTATION
>> index 2f4cfd6..8f8a945 100644
>> --- a/IMPLEMENTATION
>> +++ b/IMPLEMENTATION
>> @@ -112,3 +112,79 @@
>> unsigned long long page_flags; /* page flags */
>> } page_desc_t;
>>
>> +* The incomplete DUMPFILE
>> + When generating DUMPFILE, if ENOSPACE error happens, the DUMPFILE will be
>> + incomplete.
>> +
>> + - The incomplete kdump-compressed DUMPFILE
>> +
>> + the complete the incomplete
>> + +-----------------------+ +-----------------------+
>> + | main header | | main header | have incomplete flag
>> + |-----------------------+ |-----------------------+
>> + | sub header | | sub header |
>> + |-----------------------+ |-----------------------+
>> + | 1st-bitmap | | 1st-bitmap |
>> + |-----------------------+ |-----------------------+
>> + | 2nd-bitmap | | 2nd-bitmap |
>> + |-----------------------+ |-----------------------+
>> + | page header for pfn 0 | | page header for pfn 0 |
>> + | page header for pfn 1 | | page header for pfn 1 |
>> + | : | | : |
>> + | page header for pfn N | | page header for pfn N | The page headers after
>> + | : | | | N don't exist. The
>> + | page header for pfn Z | | | value of it is zero,
>> + |-----------------------| |-----------------------| when try to read it.
>> + | page data (pfn 0) | | page data (pfn 0) |
>> + | page data (pfn 1) | | page data (pfn 1) |
>> + | : | | : |
>> + | page data (pfn N) | | page data (pfn N) |
>> + | : | +-----------------------+
>> + | page data (pfn Z) |
>> + +-----------------------+
>> +
>> + The incomplete flag is set into status of disk_dump_header by
>> + status |= DUMP_DH_COMPRESSED_INCOMPLETE
>> + DUMP_DH_COMPRESSED_INCOMPLETE : 0x8
>> +
>> + The page header and page data are written in pairs. When writting page data
>
> s/writting/writing/
>
>> + (pfn N+1), if ENOSPACE error happens, the page headers after N won't be
>> + written either.
>> +
>> + If there is no page data dumped into the DUMPFILE, the DUMPFILE can't be
>> + analysed by crash.
>> +
>> + - The incomplete elf DUMPFILE
>
> There is no description of the ELF format itself in this documentation
> unlike the kdump-compressed format, I would be glad if you could write it.
>
>> +
>> + the complete the incomplete
>> + +-------------+ +-------------+
>> + | elf header | | elf header | have incomplete flag
>> + |-------------+ |-------------+
>> + | PT_NOTE | | PT_NOTE |
>> + | PT_LOAD(1) | | PT_LOAD(1) |
>> + | : | | : |
>> + | PT_LOAD(N) | | PT_LOAD(N) | The PT_LOAD after N don't exist.
>> + | : | | | The value of it is zero, when try
>> + | PT_LOAD(Z) | | | to read it.
>> + |-------------+ |-------------+
>
> The whole program header must exist since reserve_diskspace()
> pre-allocates enough space for it, the description above isn't right.
>
The space exists, but since PT_LOAD and segment are written in pairs,
if ENOSPACE happens, the left PT_LOAD won't be generated and won't be
written as well. The space reserved is for the PT_LOAD still in buffer.
--
Thanks
Zhou Wenjian
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH] makedumpfile: Add description of incomplete dump file
2014-11-13 9:29 ` "Zhou, Wenjian/周文剑"
@ 2014-11-14 1:21 ` Atsushi Kumagai
0 siblings, 0 replies; 4+ messages in thread
From: Atsushi Kumagai @ 2014-11-14 1:21 UTC (permalink / raw)
To: zhouwj-fnst@cn.fujitsu.com; +Cc: kexec@lists.infradead.org
>On 11/13/2014 05:01 PM, Atsushi Kumagai wrote:
>> Hello Zhou,
>>
>>> Add description of incomplete elf and kdump-compressed dump file
>>> in IMPLEMENTATION.
>>
>> That's a good idea, thanks Zhou.
>> I have some comments.
>>
>>> Signed-off-by: Qiao Nuohan<qiaonuohan@cn.fujitsu.com>
>>> Signed-off-by: Zhou Wenjian<zhouwj-fnst@cn.fujitsu.com>
>>> ---
>>> IMPLEMENTATION | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>> 1 files changed, 76 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/IMPLEMENTATION b/IMPLEMENTATION
>>> index 2f4cfd6..8f8a945 100644
>>> --- a/IMPLEMENTATION
>>> +++ b/IMPLEMENTATION
>>> @@ -112,3 +112,79 @@
>>> unsigned long long page_flags; /* page flags */
>>> } page_desc_t;
>>>
>>> +* The incomplete DUMPFILE
>>> + When generating DUMPFILE, if ENOSPACE error happens, the DUMPFILE will be
>>> + incomplete.
>>> +
>>> + - The incomplete kdump-compressed DUMPFILE
>>> +
>>> + the complete the incomplete
>>> + +-----------------------+ +-----------------------+
>>> + | main header | | main header | have incomplete flag
>>> + |-----------------------+ |-----------------------+
>>> + | sub header | | sub header |
>>> + |-----------------------+ |-----------------------+
>>> + | 1st-bitmap | | 1st-bitmap |
>>> + |-----------------------+ |-----------------------+
>>> + | 2nd-bitmap | | 2nd-bitmap |
>>> + |-----------------------+ |-----------------------+
>>> + | page header for pfn 0 | | page header for pfn 0 |
>>> + | page header for pfn 1 | | page header for pfn 1 |
>>> + | : | | : |
>>> + | page header for pfn N | | page header for pfn N | The page headers after
>>> + | : | | | N don't exist. The
>>> + | page header for pfn Z | | | value of it is zero,
>>> + |-----------------------| |-----------------------| when try to read it.
>>> + | page data (pfn 0) | | page data (pfn 0) |
>>> + | page data (pfn 1) | | page data (pfn 1) |
>>> + | : | | : |
>>> + | page data (pfn N) | | page data (pfn N) |
>>> + | : | +-----------------------+
>>> + | page data (pfn Z) |
>>> + +-----------------------+
>>> +
>>> + The incomplete flag is set into status of disk_dump_header by
>>> + status |= DUMP_DH_COMPRESSED_INCOMPLETE
>>> + DUMP_DH_COMPRESSED_INCOMPLETE : 0x8
>>> +
>>> + The page header and page data are written in pairs. When writting page data
>>
>> s/writting/writing/
>>
>>> + (pfn N+1), if ENOSPACE error happens, the page headers after N won't be
>>> + written either.
>>> +
>>> + If there is no page data dumped into the DUMPFILE, the DUMPFILE can't be
>>> + analysed by crash.
>>> +
>>> + - The incomplete elf DUMPFILE
>>
>> There is no description of the ELF format itself in this documentation
>> unlike the kdump-compressed format, I would be glad if you could write it.
>>
>>> +
>>> + the complete the incomplete
>>> + +-------------+ +-------------+
>>> + | elf header | | elf header | have incomplete flag
>>> + |-------------+ |-------------+
>>> + | PT_NOTE | | PT_NOTE |
>>> + | PT_LOAD(1) | | PT_LOAD(1) |
>>> + | : | | : |
>>> + | PT_LOAD(N) | | PT_LOAD(N) | The PT_LOAD after N don't exist.
>>> + | : | | | The value of it is zero, when try
>>> + | PT_LOAD(Z) | | | to read it.
>>> + |-------------+ |-------------+
>>
>> The whole program header must exist since reserve_diskspace()
>> pre-allocates enough space for it, the description above isn't right.
>>
>The space exists, but since PT_LOAD and segment are written in pairs,
>if ENOSPACE happens, the left PT_LOAD won't be generated and won't be
>written as well. The space reserved is for the PT_LOAD still in buffer.
Oh, it slipped my mind. You are right.
Thanks
Atsushi Kumagai
>--
>Thanks
>Zhou Wenjian
>
>_______________________________________________
>kexec mailing list
>kexec@lists.infradead.org
>http://lists.infradead.org/mailman/listinfo/kexec
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
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2014-11-12 8:29 [PATCH] makedumpfile: Add description of incomplete dump file Zhou Wenjian
2014-11-13 9:01 ` Atsushi Kumagai
2014-11-13 9:29 ` "Zhou, Wenjian/周文剑"
2014-11-14 1:21 ` Atsushi Kumagai
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