diff options
Diffstat (limited to 'sysdeps/linux-gnu/ppc/plt.c')
| -rw-r--r-- | sysdeps/linux-gnu/ppc/plt.c | 94 |
1 files changed, 75 insertions, 19 deletions
diff --git a/sysdeps/linux-gnu/ppc/plt.c b/sysdeps/linux-gnu/ppc/plt.c index 8715da6..332daa8 100644 --- a/sysdeps/linux-gnu/ppc/plt.c +++ b/sysdeps/linux-gnu/ppc/plt.c @@ -679,6 +679,14 @@ arch_elf_add_func_entry(struct process *proc, struct ltelf *lte, return PLT_OK; } +struct ppc_unresolve_data { + struct ppc_unresolve_data *self; /* A canary. */ + GElf_Addr plt_entry_addr; + GElf_Addr plt_slot_addr; + GElf_Addr plt_slot_value; + bool is_irelative; +}; + enum plt_status arch_elf_add_plt_entry(struct process *proc, struct ltelf *lte, const char *a_name, GElf_Rela *rela, size_t ndx, @@ -778,28 +786,23 @@ arch_elf_add_plt_entry(struct process *proc, struct ltelf *lte, && (plt_slot_value == plt_entry_addr || plt_slot_value == 0)) { libsym->arch.type = PPC_PLT_UNRESOLVED; libsym->arch.resolved_value = plt_entry_addr; - } else { - /* Unresolve the .plt slot. If the binary was - * prelinked, this makes the code invalid, because in - * case of prelinked binary, the dynamic linker - * doesn't update .plt[0] and .plt[1] with addresses - * of the resover. But we don't care, we will never - * need to enter the resolver. That just means that - * we have to un-un-resolve this back before we - * detach. */ - - if (unresolve_plt_slot(proc, plt_slot_addr, plt_entry_addr) < 0) { - library_symbol_destroy(libsym); + /* Mark the symbol for later unresolving. We may not + * do this right away, as this is called by ltrace + * core for all symbols, and only later filtered. We + * only unresolve the symbol before the breakpoint is + * enabled. */ + + libsym->arch.type = PPC_PLT_NEED_UNRESOLVE; + libsym->arch.data = malloc(sizeof *libsym->arch.data); + if (libsym->arch.data == NULL) goto fail2; - } - if (! is_irelative) { - mark_as_resolved(libsym, plt_slot_value); - } else { - libsym->arch.type = PPC_PLT_IRELATIVE; - libsym->arch.resolved_value = plt_entry_addr; - } + libsym->arch.data->self = libsym->arch.data; + libsym->arch.data->plt_entry_addr = plt_entry_addr; + libsym->arch.data->plt_slot_addr = plt_slot_addr; + libsym->arch.data->plt_slot_value = plt_slot_value; + libsym->arch.data->is_irelative = is_irelative; } *ret = libsym; @@ -999,6 +1002,7 @@ ppc_plt_bp_continue(struct breakpoint *bp, struct process *proc) return; case PPC64_PLT_STUB: + case PPC_PLT_NEED_UNRESOLVE: /* These should never hit here. */ break; } @@ -1050,6 +1054,52 @@ ppc_plt_bp_retract(struct breakpoint *bp, struct process *proc) } } +static void +ppc_plt_bp_install(struct breakpoint *bp, struct process *proc) +{ + /* This should not be an artificial breakpoint. */ + struct library_symbol *libsym = bp->libsym; + if (libsym == NULL) + libsym = bp->arch.irel_libsym; + assert(libsym != NULL); + + if (libsym->arch.type == PPC_PLT_NEED_UNRESOLVE) { + /* Unresolve the .plt slot. If the binary was + * prelinked, this makes the code invalid, because in + * case of prelinked binary, the dynamic linker + * doesn't update .plt[0] and .plt[1] with addresses + * of the resover. But we don't care, we will never + * need to enter the resolver. That just means that + * we have to un-un-resolve this back before we + * detach. */ + + struct ppc_unresolve_data *data = libsym->arch.data; + libsym->arch.data = NULL; + assert(data->self == data); + + GElf_Addr plt_slot_addr = data->plt_slot_addr; + GElf_Addr plt_slot_value = data->plt_slot_value; + GElf_Addr plt_entry_addr = data->plt_entry_addr; + + if (unresolve_plt_slot(proc, plt_slot_addr, + plt_entry_addr) == 0) { + if (! data->is_irelative) { + mark_as_resolved(libsym, plt_slot_value); + } else { + libsym->arch.type = PPC_PLT_IRELATIVE; + libsym->arch.resolved_value = plt_entry_addr; + } + } else { + fprintf(stderr, "Couldn't unresolve %s@%p. Not tracing" + " this symbol.\n", + breakpoint_name(bp), bp->addr); + proc_remove_breakpoint(proc, bp); + } + + free(data); + } +} + int arch_library_init(struct library *lib) { @@ -1080,6 +1130,11 @@ arch_library_symbol_init(struct library_symbol *libsym) void arch_library_symbol_destroy(struct library_symbol *libsym) { + if (libsym->arch.type == PPC_PLT_NEED_UNRESOLVE) { + assert(libsym->arch.data->self == libsym->arch.data); + free(libsym->arch.data); + libsym->arch.data = NULL; + } } int @@ -1115,6 +1170,7 @@ arch_breakpoint_init(struct process *proc, struct breakpoint *bp) static struct bp_callbacks cbs = { .on_continue = ppc_plt_bp_continue, .on_retract = ppc_plt_bp_retract, + .on_install = ppc_plt_bp_install, }; breakpoint_set_callbacks(bp, &cbs); |