Hi
On Thu, Jul 21, 2022 at 5:23 PM Janosch Frank <frankja@linux.ibm.com> wrote:
For the upcoming string table and arch section support we need to
modify the elf layout a bit. Instead of the segments, i.e. the guest's
memory contents, beeing the last area the section data will live at
the end of the file. This will allow us to write the section data
after all guest memory has been dumped which is important for the s390
PV dump support.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
dump/dump.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)
diff --git a/dump/dump.c b/dump/dump.c
index 980702d476..6f3274c5af 100644
--- a/dump/dump.c
+++ b/dump/dump.c
@@ -590,6 +590,9 @@ static void dump_begin(DumpState *s, Error **errp)
* --------------
* | memory |
* --------------
+ * | sectn data |
+ * --------------
+
*
* we only know where the memory is saved after we write elf note into
* vmcore.
@@ -1817,18 +1820,18 @@ static void dump_init(DumpState *s, int fd, bool
has_format,
}
}
+ tmp = (s->phdr_num == PN_XNUM) ? s->sh_info : s->phdr_num;
if (dump_is_64bit(s)) {
- s->phdr_offset = sizeof(Elf64_Ehdr);
- s->shdr_offset = s->phdr_offset + sizeof(Elf64_Phdr) * s->phdr_num;
- s->note_offset = s->shdr_offset + sizeof(Elf64_Shdr) * s->shdr_num;
- s->memory_offset = s->note_offset + s->note_size;
+ s->shdr_offset = sizeof(Elf64_Ehdr);
+ s->phdr_offset = s->shdr_offset + sizeof(Elf64_Shdr) * s->shdr_num;
+ s->note_offset = s->phdr_offset + sizeof(Elf64_Phdr) * tmp;
} else {
-
- s->phdr_offset = sizeof(Elf32_Ehdr);
- s->shdr_offset = s->phdr_offset + sizeof(Elf32_Phdr) * s->phdr_num;
- s->note_offset = s->shdr_offset + sizeof(Elf32_Shdr) * s->shdr_num;
- s->memory_offset = s->note_offset + s->note_size;
+ s->shdr_offset = sizeof(Elf32_Ehdr);
+ s->phdr_offset = s->shdr_offset + sizeof(Elf32_Shdr) * s->shdr_num;
+ s->note_offset = s->phdr_offset + sizeof(Elf32_Phdr) * tmp;
}
+ s->memory_offset = s->note_offset + s->note_size;
+ s->section_offset = s->memory_offset + s->total_size;
Ah! section_offset was actually added from commit e71d353360 ("dump:
Add more offset variables"), but unused until now. It's worth
explaining in the commit message.