On 06/01/2017, 07:44 AM, Josh Poimboeuf wrote:
...
> index 3fb0747..1ca5d9a 100644
> --- a/tools/objtool/elf.c
> +++ b/tools/objtool/elf.c
...
> +int elf_write_to_file(struct elf *elf, char *outfile)
> +{
> + int fd;
> + struct section *sec;
> + Elf *elfout;
> + GElf_Ehdr eh, ehout;
> + Elf_Scn *scn;
> + Elf_Data *data;
> + GElf_Shdr sh;
> +
> + fd = creat(outfile, 0777);
0755 even though it is umasked?
> + if (fd == -1) {
> + perror("creat");
> + return -1;
> + }
> +
> + elfout = elf_begin(fd, ELF_C_WRITE, NULL);
> + if (!elfout) {
> + perror("elf_begin");
> + return -1;
> + }
> +
> + if (!gelf_newehdr(elfout, gelf_getclass(elf->elf))) {
> + perror("gelf_newehdr");
> + return -1;
> + }
> +
> + if (!gelf_getehdr(elfout, &ehout)) {
This does not make much sense to do. You memset(0) it below.
> + perror("gelf_getehdr");
> + return -1;
> + }
> +
> + if (!gelf_getehdr(elf->elf, &eh)) {
> + perror("gelf_getehdr");
> + return -1;
> + }
> +
> + memset(&ehout, 0, sizeof(ehout));
> + ehout.e_ident[EI_DATA] = eh.e_ident[EI_DATA];
> + ehout.e_machine = eh.e_machine;
> + ehout.e_type = eh.e_type;
> + ehout.e_version = EV_CURRENT;
> + ehout.e_shstrndx = find_section_by_name(elf, ".shstrtab")->idx;
> +
> + list_for_each_entry(sec, &elf->sections, list) {
> + if (sec->idx == 0)
> + continue;
> +
> + scn = elf_newscn(elfout);
> + if (!scn) {
> + perror("elf_newscn");
> + return -1;
> + }
> +
> + data = elf_newdata(scn);
> + if (!data) {
> + perror("elf_newdata");
> + return -1;
> + }
> +
> + if (!elf_flagdata(data, ELF_C_SET, ELF_F_DIRTY)) {
> + perror("elf_flagdata");
> + return -1;
> + }
There is not much point setting DIRTY flag here. elf_newdata does so.
> + data->d_type = sec->data->d_type;
> + data->d_buf = sec->data->d_buf;
> + data->d_size = sec->data->d_size;
> +
> + if(!gelf_getshdr(scn, &sh)) {
> + perror("gelf_getshdr");
> + return -1;
> + }
This does not make much sense to do again. You overwrite the content
right away:
> + sh = sec->sh;
> +
> + if (!gelf_update_shdr(scn, &sh)) {
> + perror("gelf_update_shdr");
> + return -1;
> + }
> + }
> +
> + if (!gelf_update_ehdr(elfout, &ehout)) {
> + perror("gelf_update_ehdr");
> + return -1;
> + }
> +
> + if (elf_update(elfout, ELF_C_WRITE) < 0) {
> + perror("elf_update");
> + return -1;
> + }
elf_end() + close() ?
> +
> + return 0;
> +}
> +
> void elf_close(struct elf *elf)
> {
> struct section *sec, *tmpsec;
...
> --- /dev/null
> +++ b/tools/objtool/undwarf.c
> @@ -0,0 +1,308 @@
...
> +int undwarf_dump(const char *_objname)
> +{
> + struct elf *elf;
> + struct section *sec;
> + struct rela *rela;
> + struct undwarf *undwarf;
> + int nr, i;
> +
> + objname = _objname;
> +
> + elf = elf_open(objname);
> + if (!elf) {
> + WARN("error reading elf file %s\n", objname);
> + return 1;
> + }
> +
> + sec = find_section_by_name(elf, ".undwarf");
> + if (!sec || !sec->rela)
> + return 0;
> +
> + nr = sec->len / sizeof(*undwarf);
> + for (i = 0; i < nr; i++) {
...
> + }
elf_close() ?
> +
> + return 0;
> +}
thanks,
--
js
suse labs
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