diff options
Diffstat (limited to 'sysdeps/linux-gnu/ppc/plt.c')
| -rw-r--r-- | sysdeps/linux-gnu/ppc/plt.c | 135 |
1 files changed, 70 insertions, 65 deletions
diff --git a/sysdeps/linux-gnu/ppc/plt.c b/sysdeps/linux-gnu/ppc/plt.c index a43128b..c1eb7c7 100644 --- a/sysdeps/linux-gnu/ppc/plt.c +++ b/sysdeps/linux-gnu/ppc/plt.c @@ -120,6 +120,10 @@ * catch the point where the slot is resolved, would hit the return * breakpoint and that's not currently handled well. * + * On PPC32 with secure PLT, IFUNC symbols in main binary actually + * don't refer to the resolver itself. Instead they refer to a PLT + * slot. + * * XXX TODO If we have hardware watch point, we might put a read watch * on .plt slot, and discover the offenders this way. I don't know * the details, but I assume at most a handful (like, one or two, if @@ -472,6 +476,34 @@ arch_elf_init(struct ltelf *lte, struct library *lib) * value to something conspicuous. */ lib->arch.bss_plt_prelinked = -1; + /* On PPC64 and PPC32 secure, IRELATIVE relocations actually + * relocate .iplt section, and as such are stored in .rela.dyn + * (where all non-PLT relocations are stored) instead of + * .rela.plt. Add these to lte->plt_relocs. */ + + GElf_Addr rela, relasz; + Elf_Scn *rela_sec; + GElf_Shdr rela_shdr; + if ((lte->ehdr.e_machine == EM_PPC64 || lte->arch.secure_plt) + && load_dynamic_entry(lte, DT_RELA, &rela) == 0 + && load_dynamic_entry(lte, DT_RELASZ, &relasz) == 0 + && elf_get_section_covering(lte, rela, &rela_sec, &rela_shdr) == 0 + && rela_sec != NULL) { + + struct vect v; + VECT_INIT(&v, GElf_Rela); + int ret = elf_read_relocs(lte, rela_sec, &rela_shdr, &v); + if (ret >= 0 + && VECT_EACH(&v, GElf_Rela, NULL, + reloc_copy_if_irelative, lte) != NULL) + ret = -1; + + VECT_DESTROY(&v, GElf_Rela, NULL, NULL); + + if (ret < 0) + return ret; + } + if (lte->ehdr.e_machine == EM_PPC && lte->arch.secure_plt) { GElf_Addr ppcgot; if (load_dynamic_entry(lte, DT_PPC_GOT, &ppcgot) < 0) { @@ -582,33 +614,6 @@ arch_elf_init(struct ltelf *lte, struct library *lib) } } - /* On PPC64, IRELATIVE relocations actually relocate .iplt - * section, and as such are stored in .rela.dyn (where all - * non-PLT relocations are stored) instead of .rela.plt. Add - * these to lte->plt_relocs. */ - - GElf_Addr rela, relasz; - Elf_Scn *rela_sec; - GElf_Shdr rela_shdr; - if (lte->ehdr.e_machine == EM_PPC64 - && load_dynamic_entry(lte, DT_RELA, &rela) == 0 - && load_dynamic_entry(lte, DT_RELASZ, &relasz) == 0 - && elf_get_section_covering(lte, rela, &rela_sec, &rela_shdr) == 0 - && rela_sec != NULL) { - - struct vect v; - VECT_INIT(&v, GElf_Rela); - int ret = elf_read_relocs(lte, rela_sec, &rela_shdr, &v); - if (ret >= 0 - && VECT_EACH(&v, GElf_Rela, NULL, - reloc_copy_if_irelative, lte) != NULL) - ret = -1; - - VECT_DESTROY(&v, GElf_Rela, NULL, NULL); - - if (ret < 0) - return ret; - } return 0; } @@ -651,39 +656,45 @@ arch_elf_add_plt_entry(struct process *proc, struct ltelf *lte, const char *a_name, GElf_Rela *rela, size_t ndx, struct library_symbol **ret) { - if (lte->ehdr.e_machine == EM_PPC) { - if (lte->arch.secure_plt) - return PLT_DEFAULT; - - struct library_symbol *libsym = NULL; - if (default_elf_add_plt_entry(proc, lte, a_name, rela, ndx, - &libsym) < 0) - return PLT_FAIL; - - /* On PPC32 with BSS PLT, delay the symbol until - * dynamic linker is done. */ - assert(!libsym->delayed); - libsym->delayed = 1; - - *ret = libsym; - return PLT_OK; - - } - bool is_irelative = reloc_is_irelative(lte->ehdr.e_machine, rela); char *name; - if (is_irelative) - name = linux_elf_find_irelative_name(lte, rela); - else + if (! is_irelative) { name = strdup(a_name); + } else { + GElf_Addr addr = lte->ehdr.e_machine == EM_PPC64 + ? (GElf_Addr) rela->r_addend + : arch_plt_sym_val(lte, ndx, rela); + name = linux_elf_find_irelative_name(lte, addr); + } - if (name == NULL) + if (name == NULL) { + fail: + free(name); return PLT_FAIL; + } + + struct library_symbol *chain = NULL; + if (lte->ehdr.e_machine == EM_PPC) { + if (default_elf_add_plt_entry(proc, lte, name, rela, ndx, + &chain) < 0) + goto fail; + + if (! lte->arch.secure_plt) { + /* On PPC32 with BSS PLT, delay the symbol + * until dynamic linker is done. */ + assert(!chain->delayed); + chain->delayed = 1; + } + + ok: + *ret = chain; + free(name); + return PLT_OK; + } /* PPC64. If we have stubs, we return a chain of breakpoint * sites, one for each stub that corresponds to this PLT * entry. */ - struct library_symbol *chain = NULL; struct library_symbol **symp; for (symp = <e->arch.stubs; *symp != NULL; ) { struct library_symbol *sym = *symp; @@ -698,11 +709,8 @@ arch_elf_add_plt_entry(struct process *proc, struct ltelf *lte, chain = sym; } - if (chain != NULL) { - *ret = chain; - free(name); - return PLT_OK; - } + if (chain != NULL) + goto ok; /* We don't have stub symbols. Find corresponding .plt slot, * and check whether it contains the corresponding PLT address @@ -718,19 +726,16 @@ arch_elf_add_plt_entry(struct process *proc, struct ltelf *lte, || plt_slot_addr < lte->plt_addr + lte->plt_size); GElf_Addr plt_slot_value; - if (read_plt_slot_value(proc, plt_slot_addr, &plt_slot_value) < 0) { - free(name); - return PLT_FAIL; - } + if (read_plt_slot_value(proc, plt_slot_addr, &plt_slot_value) < 0) + goto fail; struct library_symbol *libsym = malloc(sizeof(*libsym)); if (libsym == NULL) { fprintf(stderr, "allocation for .plt slot: %s\n", strerror(errno)); - fail: - free(name); + fail2: free(libsym); - return PLT_FAIL; + goto fail; } /* XXX The double cast should be removed when @@ -738,7 +743,7 @@ arch_elf_add_plt_entry(struct process *proc, struct ltelf *lte, if (library_symbol_init(libsym, (arch_addr_t) (uintptr_t) plt_entry_addr, name, 1, LS_TOPLT_EXEC) < 0) - goto fail; + goto fail2; libsym->arch.plt_slot_addr = plt_slot_addr; if (! is_irelative @@ -758,7 +763,7 @@ arch_elf_add_plt_entry(struct process *proc, struct ltelf *lte, if (unresolve_plt_slot(proc, plt_slot_addr, plt_entry_addr) < 0) { library_symbol_destroy(libsym); - goto fail; + goto fail2; } if (! is_irelative) { |