| commit cda4f265c65fb6c4ce38ca1cf0a7e527c5e77cd5 |
| Author: Adhemerval Zanella <adhemerval.zanella@linaro.org> |
| 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 <fweimer@redhat.com> |
| |
| diff --git a/elf/Versions b/elf/Versions |
| index be88c48e6d45a937..c5d4342cf1f5124c 100644 |
| |
| |
| @@ -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 |
| |
| |
| @@ -16,6 +16,7 @@ |
| License along with the GNU C Library; if not, see |
| <https://www.gnu.org/licenses/>. */ |
| |
| +#include <assert.h> |
| #include <ldsodefs.h> |
| |
| 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 |
| |
| |
| @@ -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 |
| |
| |
| @@ -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 |
| |
| |
| @@ -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 |