By splitting the writing of the section headers and (future) section
data we prepare for the addition of a string table section and
architecture sections.
Signed-off-by: Janosch Frank <fran...@linux.ibm.com>
---
dump/dump.c | 116 ++++++++++++++++++++++++++++++++----------
include/sysemu/dump.h | 4 ++
2 files changed, 94 insertions(+), 26 deletions(-)
diff --git a/dump/dump.c b/dump/dump.c
index 16d7474258..467d934bc1 100644
--- a/dump/dump.c
+++ b/dump/dump.c
@@ -342,30 +342,73 @@ static void write_elf_phdr_note(DumpState *s, Error
**errp)
}
}
-static void write_elf_section(DumpState *s, int type, Error **errp)
+static size_t write_elf_section_hdr_zero(DumpState *s, void *buff)
{
- Elf32_Shdr shdr32;
- Elf64_Shdr shdr64;
- int shdr_size;
- void *shdr;
- int ret;
+ if (dump_is_64bit(s)) {
+ Elf64_Shdr *shdr64 = buff;
- if (type == 0) {
- shdr_size = sizeof(Elf32_Shdr);
- memset(&shdr32, 0, shdr_size);
- shdr32.sh_info = cpu_to_dump32(s, s->phdr_num);
- shdr = &shdr32;
+ memset(buff, 0, sizeof(Elf64_Shdr));
+ shdr64->sh_info = cpu_to_dump32(s, s->phdr_num);
} else {
- shdr_size = sizeof(Elf64_Shdr);
- memset(&shdr64, 0, shdr_size);
- shdr64.sh_info = cpu_to_dump32(s, s->phdr_num);
- shdr = &shdr64;
+ Elf32_Shdr *shdr32 = buff;
+
+ memset(buff, 0, sizeof(Elf32_Shdr));
+ shdr32->sh_info = cpu_to_dump32(s, s->phdr_num);
}
- ret = fd_write_vmcore(shdr, shdr_size, s);
+ return dump_is_64bit(s) ? sizeof(Elf64_Shdr) : sizeof(Elf32_Shdr);
+}
+
+static void prepare_elf_section_hdrs(DumpState *s)
+{
+ uint8_t *buff_hdr;
+ size_t len, sizeof_shdr;
+
+ /*
+ * Section ordering:
+ * - HDR zero (if needed)
+ */
+ sizeof_shdr = dump_is_64bit(s) ? sizeof(Elf64_Shdr) : sizeof(Elf32_Shdr);
+ len = sizeof_shdr * s->shdr_num;
+ s->elf_section_hdrs = g_malloc0(len);
+ buff_hdr = s->elf_section_hdrs;
+
+ /* Write special section first */
+ if (s->phdr_num == PN_XNUM) {
+ write_elf_section_hdr_zero(s, buff_hdr);
+ }
+}
+
+static void prepare_elf_sections(DumpState *s, Error **errp)
+{
+ if (!s->shdr_num) {
+ return;
+ }
+
+ prepare_elf_section_hdrs(s);
+}
+
+static void write_elf_section_headers(DumpState *s, Error **errp)
+{
+ size_t sizeof_shdr;
+ int ret;
+
+ sizeof_shdr = dump_is_64bit(s) ? sizeof(Elf64_Shdr) : sizeof(Elf32_Shdr);
+
+ ret = fd_write_vmcore(s->elf_section_hdrs, s->shdr_num * sizeof_shdr, s);
if (ret < 0) {
- error_setg_errno(errp, -ret,
- "dump: failed to write section header table");
+ error_setg_errno(errp, -ret, "dump: failed to write section data");
+ }
+}
+
+static void write_elf_sections(DumpState *s, Error **errp)
+{
+ int ret;
+
+ /* Write section zero */
+ ret = fd_write_vmcore(s->elf_section_data, s->elf_section_data_size, s);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "dump: failed to write section data");
}
}
@@ -557,12 +600,22 @@ static void dump_begin(DumpState *s, Error **errp)
/* Write elf header to buffer */
prepare_elf_header(s);
+ prepare_elf_sections(s, errp);
+ if (*errp) {
+ return;
+ }
+
/* Start to write stuff into files*/
write_elf_header(s, errp);
if (*errp) {
return;
}
+ write_elf_section_headers(s, errp);
+ if (*errp) {
+ return;
+ }
+
/* write PT_NOTE to vmcore */
write_elf_phdr_note(s, errp);
if (*errp) {
@@ -575,14 +628,6 @@ static void dump_begin(DumpState *s, Error **errp)
return;
}
- /* write section to vmcore */
- if (s->shdr_num) {
- write_elf_section(s, 1, errp);
- if (*errp) {
- return;
- }
- }
-
/* write notes to vmcore */
write_elf_notes(s, errp);
}
@@ -610,6 +655,19 @@ static void dump_iterate(DumpState *s, Error **errp)
}
}
+static void dump_end(DumpState *s, Error **errp)
+{
+ ERRP_GUARD();
+
+ if (!s->elf_section_data_size) {
+ return;
+ }
+ s->elf_section_data = g_malloc0(s->elf_section_data_size);
+
+ /* write sections to vmcore */
+ write_elf_sections(s, errp);
+}
+
static void create_vmcore(DumpState *s, Error **errp)
{
ERRP_GUARD();
@@ -620,6 +678,12 @@ static void create_vmcore(DumpState *s, Error **errp)
}
dump_iterate(s, errp);
+ if (*errp) {
+ return;
+ }
+
+ /* Write section data after memory has been dumped */
+ dump_end(s, errp);
}
static int write_start_flat_header(int fd)
diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h
index 736f681d01..bd49532232 100644
--- a/include/sysemu/dump.h
+++ b/include/sysemu/dump.h
@@ -172,6 +172,10 @@ typedef struct DumpState {
int64_t length; /* Length of the dump we want to dump */
void *elf_header;
+ void *elf_section_hdrs;
+ uint64_t elf_section_data_size;
+ void *elf_section_data;
+
uint8_t *note_buf; /* buffer for notes */
size_t note_buf_offset; /* the writing place in note_buf */
uint32_t nr_cpus; /* number of guest's cpu */
--
2.34.1
