commit cda4f265c65fb6c4ce38ca1cf0a7e527c5e77cd5 Author: Adhemerval Zanella Date: Tue Jul 20 15:58:35 2021 -0300 elf: Add _dl_audit_symbind_alt and _dl_audit_symbind It consolidates the code required to call la_symbind{32,64} audit callback. Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Florian Weimer diff --git a/elf/Versions b/elf/Versions index be88c48e6d45a937..c5d4342cf1f5124c 100644 --- a/elf/Versions +++ b/elf/Versions @@ -59,6 +59,7 @@ ld { _dl_argv; _dl_find_dso_for_object; _dl_get_tls_static_info; _dl_deallocate_tls; _dl_make_stack_executable; _dl_rtld_di_serinfo; _dl_starting_up; _dl_fatal_printf; + _dl_audit_symbind_alt; _rtld_global; _rtld_global_ro; # Only here for gdb while a better method is developed. diff --git a/elf/dl-audit.c b/elf/dl-audit.c index cb1c3de93cba447b..a21530f30bc5524b 100644 --- a/elf/dl-audit.c +++ b/elf/dl-audit.c @@ -16,6 +16,7 @@ License along with the GNU C Library; if not, see . */ +#include #include void @@ -106,3 +107,124 @@ _dl_audit_objclose (struct link_map *l) afct = afct->next; } } + +void +_dl_audit_symbind_alt (struct link_map *l, const ElfW(Sym) *ref, void **value, + lookup_t result) +{ + if ((l->l_audit_any_plt | result->l_audit_any_plt) == 0) + return; + + const char *strtab = (const char *) D_PTR (result, l_info[DT_STRTAB]); + /* Compute index of the symbol entry in the symbol table of the DSO with + the definition. */ + unsigned int ndx = (ref - (ElfW(Sym) *) D_PTR (result, l_info[DT_SYMTAB])); + + unsigned int altvalue = 0; + /* Synthesize a symbol record where the st_value field is the result. */ + ElfW(Sym) sym = *ref; + sym.st_value = (ElfW(Addr)) *value; + + struct audit_ifaces *afct = GLRO(dl_audit); + for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) + { + struct auditstate *match_audit = link_map_audit_state (l, cnt); + struct auditstate *result_audit = link_map_audit_state (result, cnt); + if (afct->symbind != NULL + && ((match_audit->bindflags & LA_FLG_BINDFROM) != 0 + || ((result_audit->bindflags & LA_FLG_BINDTO) + != 0))) + { + unsigned int flags = altvalue | LA_SYMB_DLSYM; + uintptr_t new_value = afct->symbind (&sym, ndx, + &match_audit->cookie, + &result_audit->cookie, + &flags, strtab + ref->st_name); + if (new_value != (uintptr_t) sym.st_value) + { + altvalue = LA_SYMB_ALTVALUE; + sym.st_value = new_value; + } + + afct = afct->next; + } + + *value = (void *) sym.st_value; + } +} +rtld_hidden_def (_dl_audit_symbind_alt) + +void +_dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result, + const ElfW(Sym) *defsym, DL_FIXUP_VALUE_TYPE *value, + lookup_t result) +{ + reloc_result->bound = result; + /* Compute index of the symbol entry in the symbol table of the DSO with the + definition. */ + reloc_result->boundndx = (defsym - (ElfW(Sym) *) D_PTR (result, + l_info[DT_SYMTAB])); + + if ((l->l_audit_any_plt | result->l_audit_any_plt) == 0) + { + /* Set all bits since this symbol binding is not interesting. */ + reloc_result->enterexit = (1u << DL_NNS) - 1; + return; + } + + /* Synthesize a symbol record where the st_value field is the result. */ + ElfW(Sym) sym = *defsym; + sym.st_value = DL_FIXUP_VALUE_ADDR (*value); + + /* Keep track whether there is any interest in tracing the call in the lower + two bits. */ + assert (DL_NNS * 2 <= sizeof (reloc_result->flags) * 8); + assert ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) == 3); + reloc_result->enterexit = LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT; + + const char *strtab2 = (const void *) D_PTR (result, l_info[DT_STRTAB]); + + unsigned int flags = 0; + struct audit_ifaces *afct = GLRO(dl_audit); + for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) + { + /* XXX Check whether both DSOs must request action or only one */ + struct auditstate *l_state = link_map_audit_state (l, cnt); + struct auditstate *result_state = link_map_audit_state (result, cnt); + if ((l_state->bindflags & LA_FLG_BINDFROM) != 0 + && (result_state->bindflags & LA_FLG_BINDTO) != 0) + { + if (afct->symbind != NULL) + { + uintptr_t new_value = afct->symbind (&sym, + reloc_result->boundndx, + &l_state->cookie, + &result_state->cookie, + &flags, + strtab2 + defsym->st_name); + if (new_value != (uintptr_t) sym.st_value) + { + flags |= LA_SYMB_ALTVALUE; + sym.st_value = new_value; + } + } + + /* Remember the results for every audit library and store a summary + in the first two bits. */ + reloc_result->enterexit &= flags & (LA_SYMB_NOPLTENTER + | LA_SYMB_NOPLTEXIT); + reloc_result->enterexit |= ((flags & (LA_SYMB_NOPLTENTER + | LA_SYMB_NOPLTEXIT)) + << ((cnt + 1) * 2)); + } + else + /* If the bind flags say this auditor is not interested, set the bits + manually. */ + reloc_result->enterexit |= ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) + << ((cnt + 1) * 2)); + afct = afct->next; + } + + reloc_result->flags = flags; + *value = DL_FIXUP_ADDR_VALUE (sym.st_value); +} diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c index 4ccd7c30678fafad..d4840a7c17441126 100644 --- a/elf/dl-runtime.c +++ b/elf/dl-runtime.c @@ -296,84 +296,7 @@ _dl_profile_fixup ( auditing libraries the possibility to change the value and tell us whether further auditing is wanted. */ if (defsym != NULL && GLRO(dl_naudit) > 0) - { - reloc_result->bound = result; - /* Compute index of the symbol entry in the symbol table of - the DSO with the definition. */ - reloc_result->boundndx = (defsym - - (ElfW(Sym) *) D_PTR (result, - l_info[DT_SYMTAB])); - - /* Determine whether any of the two participating DSOs is - interested in auditing. */ - if ((l->l_audit_any_plt | result->l_audit_any_plt) != 0) - { - unsigned int flags = 0; - struct audit_ifaces *afct = GLRO(dl_audit); - /* Synthesize a symbol record where the st_value field is - the result. */ - ElfW(Sym) sym = *defsym; - sym.st_value = DL_FIXUP_VALUE_ADDR (value); - - /* Keep track whether there is any interest in tracing - the call in the lower two bits. */ - assert (DL_NNS * 2 <= sizeof (reloc_result->flags) * 8); - assert ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) == 3); - reloc_result->enterexit = LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT; - - const char *strtab2 = (const void *) D_PTR (result, - l_info[DT_STRTAB]); - - for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) - { - /* XXX Check whether both DSOs must request action or - only one */ - struct auditstate *l_state = link_map_audit_state (l, cnt); - struct auditstate *result_state - = link_map_audit_state (result, cnt); - if ((l_state->bindflags & LA_FLG_BINDFROM) != 0 - && (result_state->bindflags & LA_FLG_BINDTO) != 0) - { - if (afct->symbind != NULL) - { - uintptr_t new_value - = afct->symbind (&sym, reloc_result->boundndx, - &l_state->cookie, - &result_state->cookie, - &flags, - strtab2 + defsym->st_name); - if (new_value != (uintptr_t) sym.st_value) - { - flags |= LA_SYMB_ALTVALUE; - sym.st_value = new_value; - } - } - - /* Remember the results for every audit library and - store a summary in the first two bits. */ - reloc_result->enterexit - &= flags & (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT); - reloc_result->enterexit - |= ((flags & (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT)) - << ((cnt + 1) * 2)); - } - else - /* If the bind flags say this auditor is not interested, - set the bits manually. */ - reloc_result->enterexit - |= ((LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) - << ((cnt + 1) * 2)); - - afct = afct->next; - } - - reloc_result->flags = flags; - value = DL_FIXUP_ADDR_VALUE (sym.st_value); - } - else - /* Set all bits since this symbol binding is not interesting. */ - reloc_result->enterexit = (1u << DL_NNS) - 1; - } + _dl_audit_symbind (l, reloc_result, defsym, &value, result); #endif /* Store the result for later runs. */ diff --git a/elf/dl-sym-post.h b/elf/dl-sym-post.h index 4c4f574633497789..f33934c92047f293 100644 --- a/elf/dl-sym-post.h +++ b/elf/dl-sym-post.h @@ -52,54 +52,9 @@ _dl_sym_post (lookup_t result, const ElfW(Sym) *ref, void *value, tell us whether further auditing is wanted. */ if (__glibc_unlikely (GLRO(dl_naudit) > 0)) { - const char *strtab = (const char *) D_PTR (result, - l_info[DT_STRTAB]); - /* Compute index of the symbol entry in the symbol table of - the DSO with the definition. */ - unsigned int ndx = (ref - (ElfW(Sym) *) D_PTR (result, - l_info[DT_SYMTAB])); - if (match == NULL) match = _dl_sym_find_caller_link_map (caller); - - if ((match->l_audit_any_plt | result->l_audit_any_plt) != 0) - { - unsigned int altvalue = 0; - struct audit_ifaces *afct = GLRO(dl_audit); - /* Synthesize a symbol record where the st_value field is - the result. */ - ElfW(Sym) sym = *ref; - sym.st_value = (ElfW(Addr)) value; - - for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) - { - struct auditstate *match_audit - = link_map_audit_state (match, cnt); - struct auditstate *result_audit - = link_map_audit_state (result, cnt); - if (afct->symbind != NULL - && ((match_audit->bindflags & LA_FLG_BINDFROM) != 0 - || ((result_audit->bindflags & LA_FLG_BINDTO) - != 0))) - { - unsigned int flags = altvalue | LA_SYMB_DLSYM; - uintptr_t new_value - = afct->symbind (&sym, ndx, - &match_audit->cookie, - &result_audit->cookie, - &flags, strtab + ref->st_name); - if (new_value != (uintptr_t) sym.st_value) - { - altvalue = LA_SYMB_ALTVALUE; - sym.st_value = new_value; - } - } - - afct = afct->next; - } - - value = (void *) sym.st_value; - } + _dl_audit_symbind_alt (match, ref, &value, result); } #endif return value; diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h index 3db25c5be1acf871..fa55c3bde10de52e 100644 --- a/sysdeps/generic/ldsodefs.h +++ b/sysdeps/generic/ldsodefs.h @@ -1294,6 +1294,16 @@ void _dl_audit_objopen (struct link_map *l, Lmid_t nsid) /* Call the la_objclose from the audit modules for the link_map L. */ void _dl_audit_objclose (struct link_map *l) attribute_hidden; + +/* Call the la_symbind{32,64} from the audit modules for the link_map L. */ +void _dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result, + const ElfW(Sym) *defsym, DL_FIXUP_VALUE_TYPE *value, + lookup_t result) + attribute_hidden; +/* Same as _dl_audit_symbind, but also sets LA_SYMB_DLSYM flag. */ +void _dl_audit_symbind_alt (struct link_map *l, const ElfW(Sym) *ref, + void **value, lookup_t result); +rtld_hidden_proto (_dl_audit_symbind_alt) #endif /* SHARED */ __END_DECLS