From 979d2ab7da0c65ad060eded05d4fe5bd0911df8e Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Sat, 2 Nov 2019 20:04:02 +0100 Subject: [PATCH 13/19] Introduce link_map_audit_state accessor function To improve GCC 10 compatibility, it is necessary to remove the l_audit zero-length array from the end of struct link_map. In preparation of that, this commit introduces an accessor function for the audit state, so that it is possible to change the representation of the audit state without adjusting the code that accesses it. Tested on x86_64-linux-gnu. Built on i686-gnu. Change-Id: Id815673c29950fc011ae5301d7cde12624f658df (cherry picked from commit e1d559f337de2c8ab68a6749dfe873477c883807) Signed-off-by: Jeffy Chen --- csu/libc-start.c | 2 +- elf/dl-close.c | 18 ++++++++++++++---- elf/dl-fini.c | 9 ++++++--- elf/dl-load.c | 18 +++++++++--------- elf/dl-object.c | 8 +++----- elf/dl-open.c | 5 ++++- elf/dl-runtime.c | 24 ++++++++++++++++-------- elf/dl-sym.c | 13 ++++++++----- elf/rtld.c | 18 ++++++++++-------- sysdeps/generic/ldsodefs.h | 8 +++++++- 10 files changed, 78 insertions(+), 45 deletions(-) diff --git a/csu/libc-start.c b/csu/libc-start.c index 9450fb80..25b992f4 100644 --- a/csu/libc-start.c +++ b/csu/libc-start.c @@ -273,7 +273,7 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL), for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) { if (afct->preinit != NULL) - afct->preinit (&head->l_audit[cnt].cookie); + afct->preinit (&link_map_audit_state (head, cnt)->cookie); afct = afct->next; } diff --git a/elf/dl-close.c b/elf/dl-close.c index 4aef95a1..ad379072 100644 --- a/elf/dl-close.c +++ b/elf/dl-close.c @@ -302,8 +302,12 @@ _dl_close_worker (struct link_map *map, bool force) for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) { if (afct->objclose != NULL) - /* Return value is ignored. */ - (void) afct->objclose (&imap->l_audit[cnt].cookie); + { + struct auditstate *state + = link_map_audit_state (imap, cnt); + /* Return value is ignored. */ + (void) afct->objclose (&state->cookie); + } afct = afct->next; } @@ -478,7 +482,10 @@ _dl_close_worker (struct link_map *map, bool force) for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) { if (afct->activity != NULL) - afct->activity (&head->l_audit[cnt].cookie, LA_ACT_DELETE); + { + struct auditstate *state = link_map_audit_state (head, cnt); + afct->activity (&state->cookie, LA_ACT_DELETE); + } afct = afct->next; } @@ -774,7 +781,10 @@ _dl_close_worker (struct link_map *map, bool force) for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) { if (afct->activity != NULL) - afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT); + { + struct auditstate *state = link_map_audit_state (head, cnt); + afct->activity (&state->cookie, LA_ACT_CONSISTENT); + } afct = afct->next; } diff --git a/elf/dl-fini.c b/elf/dl-fini.c index 1e55d398..94618b45 100644 --- a/elf/dl-fini.c +++ b/elf/dl-fini.c @@ -152,9 +152,12 @@ _dl_fini (void) for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) { if (afct->objclose != NULL) - /* Return value is ignored. */ - (void) afct->objclose (&l->l_audit[cnt].cookie); - + { + struct auditstate *state + = link_map_audit_state (l, cnt); + /* Return value is ignored. */ + (void) afct->objclose (&state->cookie); + } afct = afct->next; } } diff --git a/elf/dl-load.c b/elf/dl-load.c index f9725244..515fd164 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -978,7 +978,8 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) { if (afct->activity != NULL) - afct->activity (&head->l_audit[cnt].cookie, LA_ACT_ADD); + afct->activity (&link_map_audit_state (head, cnt)->cookie, + LA_ACT_ADD); afct = afct->next; } @@ -1391,10 +1392,9 @@ cannot enable executable stack as shared object requires"); { if (afct->objopen != NULL) { - l->l_audit[cnt].bindflags - = afct->objopen (l, nsid, &l->l_audit[cnt].cookie); - - l->l_audit_any_plt |= l->l_audit[cnt].bindflags != 0; + struct auditstate *state = link_map_audit_state (l, cnt); + state->bindflags = afct->objopen (l, nsid, &state->cookie); + l->l_audit_any_plt |= state->bindflags != 0; } afct = afct->next; @@ -1500,8 +1500,8 @@ open_verify (const char *name, int fd, { if (afct->objsearch != NULL) { - name = afct->objsearch (name, &loader->l_audit[cnt].cookie, - whatcode); + struct auditstate *state = link_map_audit_state (loader, cnt); + name = afct->objsearch (name, &state->cookie, whatcode); if (name == NULL) /* Ignore the path. */ return -1; @@ -1982,8 +1982,8 @@ _dl_map_object (struct link_map *loader, const char *name, if (afct->objsearch != NULL) { const char *before = name; - name = afct->objsearch (name, &loader->l_audit[cnt].cookie, - LA_SER_ORIG); + struct auditstate *state = link_map_audit_state (loader, cnt); + name = afct->objsearch (name, &state->cookie, LA_SER_ORIG); if (name == NULL) { /* Do not try anything further. */ diff --git a/elf/dl-object.c b/elf/dl-object.c index c3f5455a..84c8ea7e 100644 --- a/elf/dl-object.c +++ b/elf/dl-object.c @@ -65,7 +65,7 @@ _dl_new_object (char *realname, const char *libname, int type, auditing libraries and if yes, how many. Assume the worst. */ unsigned int naudit = GLRO(dl_naudit) ?: ((mode & __RTLD_OPENEXEC) ? DL_NNS : 0); - size_t audit_space = naudit * sizeof (new->l_audit[0]); + size_t audit_space = naudit * sizeof (struct auditstate); #else # define audit_space 0 #endif @@ -106,10 +106,8 @@ _dl_new_object (char *realname, const char *libname, int type, #ifdef SHARED for (unsigned int cnt = 0; cnt < naudit; ++cnt) - { - new->l_audit[cnt].cookie = (uintptr_t) new; - /* new->l_audit[cnt].bindflags = 0; */ - } + /* No need to initialize bindflags due to calloc. */ + link_map_audit_state (new, cnt)->cookie = (uintptr_t) new; #endif /* new->l_global = 0; We use calloc therefore not necessary. */ diff --git a/elf/dl-open.c b/elf/dl-open.c index 12a4f8b8..6bcb9edd 100644 --- a/elf/dl-open.c +++ b/elf/dl-open.c @@ -278,7 +278,10 @@ dl_open_worker (void *a) for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) { if (afct->activity != NULL) - afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT); + { + struct auditstate *state = link_map_audit_state (head, cnt); + afct->activity (&state->cookie, LA_ACT_CONSISTENT); + } afct = afct->next; } diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c index 42a2539e..323ac6aa 100644 --- a/elf/dl-runtime.c +++ b/elf/dl-runtime.c @@ -325,15 +325,18 @@ _dl_profile_fixup ( { /* XXX Check whether both DSOs must request action or only one */ - if ((l->l_audit[cnt].bindflags & LA_FLG_BINDFROM) != 0 - && (result->l_audit[cnt].bindflags & LA_FLG_BINDTO) != 0) + 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->l_audit[cnt].cookie, - &result->l_audit[cnt].cookie, + &l_state->cookie, + &result_state->cookie, &flags, strtab2 + defsym->st_name); if (new_value != (uintptr_t) sym.st_value) @@ -421,10 +424,13 @@ _dl_profile_fixup ( & (LA_SYMB_NOPLTENTER << (2 * (cnt + 1)))) == 0) { long int new_framesize = -1; + struct auditstate *l_state = link_map_audit_state (l, cnt); + struct auditstate *bound_state + = link_map_audit_state (reloc_result->bound, cnt); uintptr_t new_value = afct->ARCH_LA_PLTENTER (&sym, reloc_result->boundndx, - &l->l_audit[cnt].cookie, - &reloc_result->bound->l_audit[cnt].cookie, + &l_state->cookie, + &bound_state->cookie, regs, &flags, symname, &new_framesize); if (new_value != (uintptr_t) sym.st_value) @@ -504,9 +510,11 @@ _dl_call_pltexit (struct link_map *l, ElfW(Word) reloc_arg, && (reloc_result->enterexit & (LA_SYMB_NOPLTEXIT >> (2 * cnt))) == 0) { + struct auditstate *l_state = link_map_audit_state (l, cnt); + struct auditstate *bound_state + = link_map_audit_state (reloc_result->bound, cnt); afct->ARCH_LA_PLTEXIT (&sym, reloc_result->boundndx, - &l->l_audit[cnt].cookie, - &reloc_result->bound->l_audit[cnt].cookie, + &l_state->cookie, &bound_state->cookie, inregs, outregs, symname); } diff --git a/elf/dl-sym.c b/elf/dl-sym.c index 19a9b95b..81c6b574 100644 --- a/elf/dl-sym.c +++ b/elf/dl-sym.c @@ -198,17 +198,20 @@ RTLD_NEXT used in code not dynamically loaded")); 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->l_audit[cnt].bindflags & LA_FLG_BINDFROM) - != 0 - || ((result->l_audit[cnt].bindflags & LA_FLG_BINDTO) + && ((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->l_audit[cnt].cookie, - &result->l_audit[cnt].cookie, + &match_audit->cookie, + &result_audit->cookie, &flags, strtab + ref->st_name); if (new_value != (uintptr_t) sym.st_value) { diff --git a/elf/rtld.c b/elf/rtld.c index 46fc53b1..e1a33bd3 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1007,9 +1007,9 @@ ERROR: audit interface '%s' requires version %d (maximum supported version %d); else *last_audit = (*last_audit)->next = &newp->ifaces; - /* The dynamic linker link map is statically allocated, initialize - the data now. */ - GL (dl_rtld_map).l_audit[GLRO (dl_naudit)].cookie + /* The dynamic linker link map is statically allocated, so the + cookie in _dl_new_object has not happened. */ + link_map_audit_state (&GL (dl_rtld_map), GLRO (dl_naudit))->cookie = (intptr_t) &GL (dl_rtld_map); ++GLRO(dl_naudit); @@ -1028,9 +1028,9 @@ notify_audit_modules_of_loaded_object (struct link_map *map) { if (afct->objopen != NULL) { - map->l_audit[cnt].bindflags - = afct->objopen (map, LM_ID_BASE, &map->l_audit[cnt].cookie); - map->l_audit_any_plt |= map->l_audit[cnt].bindflags != 0; + struct auditstate *state = link_map_audit_state (map, cnt); + state->bindflags = afct->objopen (map, LM_ID_BASE, &state->cookie); + map->l_audit_any_plt |= state->bindflags != 0; } afct = afct->next; @@ -1642,7 +1642,8 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) { if (afct->activity != NULL) - afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD); + afct->activity (&link_map_audit_state (main_map, cnt)->cookie, + LA_ACT_ADD); afct = afct->next; } @@ -2318,7 +2319,8 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]); for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) { if (afct->activity != NULL) - afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT); + afct->activity (&link_map_audit_state (head, cnt)->cookie, + LA_ACT_CONSISTENT); afct = afct->next; } diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h index 52eca9d0..9e1356bc 100644 --- a/sysdeps/generic/ldsodefs.h +++ b/sysdeps/generic/ldsodefs.h @@ -1166,7 +1166,13 @@ rtld_active (void) initialized and active ld.so copy. */ return GLRO(dl_init_all_dirs) != NULL; } -#endif + +static inline struct auditstate * +link_map_audit_state (struct link_map *l, size_t index) +{ + return &l->l_audit[index]; +} +#endif /* SHARED */ __END_DECLS -- 2.20.1