| Message ID | 20220726092248.128336-11-frankja@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | dump: Add arch section and s390x PV dump | expand |
Hi On Tue, Jul 26, 2022 at 1:23 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 being > 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 ++++++++++++--------- > include/sysemu/dump.h | 1 + > 2 files changed, 13 insertions(+), 9 deletions(-) > > diff --git a/dump/dump.c b/dump/dump.c > index a6bb7bfa21..3cf846d0a0 100644 > --- a/dump/dump.c > +++ b/dump/dump.c > @@ -588,6 +588,9 @@ 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. > @@ -1852,18 +1855,18 @@ 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; > > return; > > diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h > index 3937afe0f9..696e6c67d6 100644 > --- a/include/sysemu/dump.h > +++ b/include/sysemu/dump.h > @@ -172,6 +172,7 @@ typedef struct DumpState { > hwaddr shdr_offset; > hwaddr phdr_offset; > hwaddr note_offset; > + hwaddr section_offset; Maybe introduce back section_offset in a different patch. Either way, Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> > > void *elf_header; > void *elf_section_hdrs; > -- > 2.34.1 >
You swapped the headers in patch 8, you just fixing up the elf header in this patch, right? Also I don't understand the reason for swapping the headers. And the comment diagram in dump_begin still reflects the old ordering. On 7/26/22 11:22, Janosch Frank 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 ++++++++++++--------- > include/sysemu/dump.h | 1 + > 2 files changed, 13 insertions(+), 9 deletions(-) > > diff --git a/dump/dump.c b/dump/dump.c > index a6bb7bfa21..3cf846d0a0 100644 > --- a/dump/dump.c > +++ b/dump/dump.c > @@ -588,6 +588,9 @@ 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. > @@ -1852,18 +1855,18 @@ static void dump_init(DumpState *s, int fd, bool has_format, > } > } > > + tmp = (s->phdr_num == PN_XNUM) ? s->sh_info : s->phdr_num; You don't need this, do you? s->phdr_num is the correct value, it's the value in the elf header that gets adjusted. > 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; > > return; > > diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h > index 3937afe0f9..696e6c67d6 100644 > --- a/include/sysemu/dump.h > +++ b/include/sysemu/dump.h > @@ -172,6 +172,7 @@ typedef struct DumpState { > hwaddr shdr_offset; > hwaddr phdr_offset; > hwaddr note_offset; > + hwaddr section_offset; > > void *elf_header; > void *elf_section_hdrs;
diff --git a/dump/dump.c b/dump/dump.c index a6bb7bfa21..3cf846d0a0 100644 --- a/dump/dump.c +++ b/dump/dump.c @@ -588,6 +588,9 @@ 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. @@ -1852,18 +1855,18 @@ 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; return; diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h index 3937afe0f9..696e6c67d6 100644 --- a/include/sysemu/dump.h +++ b/include/sysemu/dump.h @@ -172,6 +172,7 @@ typedef struct DumpState { hwaddr shdr_offset; hwaddr phdr_offset; hwaddr note_offset; + hwaddr section_offset; void *elf_header; void *elf_section_hdrs;
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 ++++++++++++--------- include/sysemu/dump.h | 1 + 2 files changed, 13 insertions(+), 9 deletions(-)