On Thu, Aug 11, 2022 at 4:29 PM Janosch Frank <fran...@linux.ibm.com> wrote:
> Let's split the write from the modification of the elf header so we
> can consolidate the write of the data in one function.
>
> Signed-off-by: Janosch Frank <fran...@linux.ibm.com>
>
Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> ---
> dump/dump.c | 100 ++++++++++++++++++++++++++++------------------------
> 1 file changed, 53 insertions(+), 47 deletions(-)
>
> diff --git a/dump/dump.c b/dump/dump.c
> index d82cc46d7d..8a2a97a85e 100644
> --- a/dump/dump.c
> +++ b/dump/dump.c
> @@ -131,7 +131,7 @@ static int fd_write_vmcore(const void *buf, size_t
> size, void *opaque)
> return 0;
> }
>
> -static void write_elf64_header(DumpState *s, Error **errp)
> +static void prepare_elf64_header(DumpState *s, Elf64_Ehdr *elf_header)
> {
> /*
> * phnum in the elf header is 16 bit, if we have more segments we
> @@ -139,34 +139,27 @@ static void write_elf64_header(DumpState *s, Error
> **errp)
> * special section.
> */
> uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
> - Elf64_Ehdr elf_header;
> - int ret;
>
> - memset(&elf_header, 0, sizeof(Elf64_Ehdr));
> - memcpy(&elf_header, ELFMAG, SELFMAG);
> - elf_header.e_ident[EI_CLASS] = ELFCLASS64;
> - elf_header.e_ident[EI_DATA] = s->dump_info.d_endian;
> - elf_header.e_ident[EI_VERSION] = EV_CURRENT;
> - elf_header.e_type = cpu_to_dump16(s, ET_CORE);
> - elf_header.e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
> - elf_header.e_version = cpu_to_dump32(s, EV_CURRENT);
> - elf_header.e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
> - elf_header.e_phoff = cpu_to_dump64(s, s->phdr_offset);
> - elf_header.e_phentsize = cpu_to_dump16(s, sizeof(Elf64_Phdr));
> - elf_header.e_phnum = cpu_to_dump16(s, phnum);
> + memset(elf_header, 0, sizeof(Elf64_Ehdr));
> + memcpy(elf_header, ELFMAG, SELFMAG);
> + elf_header->e_ident[EI_CLASS] = ELFCLASS64;
> + elf_header->e_ident[EI_DATA] = s->dump_info.d_endian;
> + elf_header->e_ident[EI_VERSION] = EV_CURRENT;
> + elf_header->e_type = cpu_to_dump16(s, ET_CORE);
> + elf_header->e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
> + elf_header->e_version = cpu_to_dump32(s, EV_CURRENT);
> + elf_header->e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
> + elf_header->e_phoff = cpu_to_dump64(s, s->phdr_offset);
> + elf_header->e_phentsize = cpu_to_dump16(s, sizeof(Elf64_Phdr));
> + elf_header->e_phnum = cpu_to_dump16(s, phnum);
> if (s->shdr_num) {
> - elf_header.e_shoff = cpu_to_dump64(s, s->shdr_offset);
> - elf_header.e_shentsize = cpu_to_dump16(s, sizeof(Elf64_Shdr));
> - elf_header.e_shnum = cpu_to_dump16(s, s->shdr_num);
> - }
> -
> - ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
> - if (ret < 0) {
> - error_setg_errno(errp, -ret, "dump: failed to write elf header");
> + elf_header->e_shoff = cpu_to_dump64(s, s->shdr_offset);
> + elf_header->e_shentsize = cpu_to_dump16(s, sizeof(Elf64_Shdr));
> + elf_header->e_shnum = cpu_to_dump16(s, s->shdr_num);
> }
> }
>
> -static void write_elf32_header(DumpState *s, Error **errp)
> +static void prepare_elf32_header(DumpState *s, Elf32_Ehdr *elf_header)
> {
> /*
> * phnum in the elf header is 16 bit, if we have more segments we
> @@ -174,28 +167,45 @@ static void write_elf32_header(DumpState *s, Error
> **errp)
> * special section.
> */
> uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
> - Elf32_Ehdr elf_header;
> +
> + memset(elf_header, 0, sizeof(Elf32_Ehdr));
> + memcpy(elf_header, ELFMAG, SELFMAG);
> + elf_header->e_ident[EI_CLASS] = ELFCLASS32;
> + elf_header->e_ident[EI_DATA] = s->dump_info.d_endian;
> + elf_header->e_ident[EI_VERSION] = EV_CURRENT;
> + elf_header->e_type = cpu_to_dump16(s, ET_CORE);
> + elf_header->e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
> + elf_header->e_version = cpu_to_dump32(s, EV_CURRENT);
> + elf_header->e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
> + elf_header->e_phoff = cpu_to_dump32(s, s->phdr_offset);
> + elf_header->e_phentsize = cpu_to_dump16(s, sizeof(Elf32_Phdr));
> + elf_header->e_phnum = cpu_to_dump16(s, phnum);
> + if (s->shdr_num) {
> + elf_header->e_shoff = cpu_to_dump32(s, s->shdr_offset);
> + elf_header->e_shentsize = cpu_to_dump16(s, sizeof(Elf32_Shdr));
> + elf_header->e_shnum = cpu_to_dump16(s, s->shdr_num);
> + }
> +}
> +
> +static void write_elf_header(DumpState *s, Error **errp)
> +{
> + Elf32_Ehdr elf32_header;
> + Elf64_Ehdr elf64_header;
> + size_t header_size;
> + void *header_ptr;
> int ret;
>
> - memset(&elf_header, 0, sizeof(Elf32_Ehdr));
> - memcpy(&elf_header, ELFMAG, SELFMAG);
> - elf_header.e_ident[EI_CLASS] = ELFCLASS32;
> - elf_header.e_ident[EI_DATA] = s->dump_info.d_endian;
> - elf_header.e_ident[EI_VERSION] = EV_CURRENT;
> - elf_header.e_type = cpu_to_dump16(s, ET_CORE);
> - elf_header.e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
> - elf_header.e_version = cpu_to_dump32(s, EV_CURRENT);
> - elf_header.e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
> - elf_header.e_phoff = cpu_to_dump32(s, s->phdr_offset);
> - elf_header.e_phentsize = cpu_to_dump16(s, sizeof(Elf32_Phdr));
> - elf_header.e_phnum = cpu_to_dump16(s, phnum);
> - if (s->shdr_num) {
> - elf_header.e_shoff = cpu_to_dump32(s, s->shdr_offset);
> - elf_header.e_shentsize = cpu_to_dump16(s, sizeof(Elf32_Shdr));
> - elf_header.e_shnum = cpu_to_dump16(s, s->shdr_num);
> + if (dump_is_64bit(s)) {
> + prepare_elf64_header(s, &elf64_header);
> + header_size = sizeof(elf64_header);
> + header_ptr = &elf64_header;
> + } else {
> + prepare_elf32_header(s, &elf32_header);
> + header_size = sizeof(elf32_header);
> + header_ptr = &elf32_header;
> }
>
> - ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
> + ret = fd_write_vmcore(header_ptr, header_size, s);
> if (ret < 0) {
> error_setg_errno(errp, -ret, "dump: failed to write elf header");
> }
> @@ -564,11 +574,7 @@ static void dump_begin(DumpState *s, Error **errp)
> */
>
> /* write elf header to vmcore */
> - if (dump_is_64bit(s)) {
> - write_elf64_header(s, errp);
> - } else {
> - write_elf32_header(s, errp);
> - }
> + write_elf_header(s, errp);
> if (*errp) {
> return;
> }
> --
> 2.34.1
>
>
>
--
Marc-André Lureau
