diff options
| author | Zhou Wenjian <zhouwj-fnst@cn.fujitsu.com> | 2014-11-14 17:22:54 +0900 |
|---|---|---|
| committer | Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp> | 2014-11-14 17:22:54 +0900 |
| commit | b343067161b5afbe3e0f2de0a01b709c19a8db80 (patch) | |
| tree | 81c974cea3ed189b210eb23659b7b6ca4e9a9403 /IMPLEMENTATION | |
| parent | 4074bb635569e4e10d9310e77d93dc63e521d25e (diff) | |
[PATCH 2/2] Add description of incomplete dump file.
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>
Diffstat (limited to 'IMPLEMENTATION')
| -rw-r--r-- | IMPLEMENTATION | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/IMPLEMENTATION b/IMPLEMENTATION index 33cac70..7ae7aa1 100644 --- a/IMPLEMENTATION +++ b/IMPLEMENTATION @@ -200,3 +200,79 @@ - segments The data dumped are all stored in segments and notes. + + +* 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 writing 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. + |-------------+ |-------------+ + | NOTE | | 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 writing 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. |