From patchwork Thu Oct 13 11:35:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 58755 From: fweimer@redhat.com (Florian Weimer) Date: Thu, 13 Oct 2022 13:35:36 +0200 List-Id: Libc-alpha mailing list Subject: [PATCH] elf: Introduce to _dl_call_fini Message-ID: <87zge0x8fr.fsf@oldenburg.str.redhat.com> This consolidates the destructor invocations from _dl_fini and dlclose. Remove the micro-optimization that avoids calling _dl_call_fini if they are no destructors (as dlclose is quite expensive anyway). Reviewed-by: Adhemerval Zanella --- elf/Makefile | 1 + elf/dl-call_fini.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++ elf/dl-close.c | 42 +------------------------------------- elf/dl-fini.c | 38 +---------------------------------- sysdeps/generic/ldsodefs.h | 8 ++++++++ 5 files changed, 61 insertions(+), 78 deletions(-) base-commit: 264db94040c463d9bc356101595d89335586875e diff --git a/elf/Makefile b/elf/Makefile index 7b50ccc07a..86c960cf8a 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -53,6 +53,7 @@ routines = \ # profiled libraries. dl-routines = \ dl-call-libc-early-init \ + dl-call_fini \ dl-close \ dl-debug \ dl-debug-symbols \ diff --git a/elf/dl-call_fini.c b/elf/dl-call_fini.c new file mode 100644 index 0000000000..383dfd093e --- /dev/null +++ b/elf/dl-call_fini.c @@ -0,0 +1,50 @@ +/* Invoke DT_FINI and DT_FINI_ARRAY callbacks. + Copyright (C) 1996-2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include + +void +_dl_call_fini (void *closure_map) +{ + struct link_map *map = closure_map; + + /* When debugging print a message first. */ + if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS, 0)) + _dl_debug_printf ("\ncalling fini: %s [%lu]\n\n", map->l_name, map->l_ns); + + /* Make sure nothing happens if we are called twice. */ + map->l_init_called = 0; + + ElfW(Dyn) *fini_array = map->l_info[DT_FINI_ARRAY]; + if (fini_array != NULL) + { + ElfW(Addr) *array = (ElfW(Addr) *) (map->l_addr + + fini_array->d_un.d_ptr); + unsigned int sz = (map->l_info[DT_FINI_ARRAYSZ]->d_un.d_val + / sizeof (ElfW(Addr))); + + while (sz-- > 0) + ((fini_t) array[sz]) (); + } + + /* Next try the old-style destructor. */ + ElfW(Dyn) *fini = map->l_info[DT_FINI]; + if (fini != NULL) + DL_CALL_DT_FINI (map, ((void *) map->l_addr + fini->d_un.d_ptr)); +} diff --git a/elf/dl-close.c b/elf/dl-close.c index bcd6e206e9..14deca2e2b 100644 --- a/elf/dl-close.c +++ b/elf/dl-close.c @@ -36,11 +36,6 @@ #include - -/* Type of the constructor functions. */ -typedef void (*fini_t) (void); - - /* Special l_idx value used to indicate which objects remain loaded. */ #define IDX_STILL_USED -1 @@ -110,31 +105,6 @@ remove_slotinfo (size_t idx, struct dtv_slotinfo_list *listp, size_t disp, return false; } -/* Invoke dstructors for CLOSURE (a struct link_map *). Called with - exception handling temporarily disabled, to make errors fatal. */ -static void -call_destructors (void *closure) -{ - struct link_map *map = closure; - - if (map->l_info[DT_FINI_ARRAY] != NULL) - { - ElfW(Addr) *array = - (ElfW(Addr) *) (map->l_addr - + map->l_info[DT_FINI_ARRAY]->d_un.d_ptr); - unsigned int sz = (map->l_info[DT_FINI_ARRAYSZ]->d_un.d_val - / sizeof (ElfW(Addr))); - - while (sz-- > 0) - ((fini_t) array[sz]) (); - } - - /* Next try the old-style destructor. */ - if (map->l_info[DT_FINI] != NULL) - DL_CALL_DT_FINI (map, ((void *) map->l_addr - + map->l_info[DT_FINI]->d_un.d_ptr)); -} - void _dl_close_worker (struct link_map *map, bool force) { @@ -280,17 +250,7 @@ _dl_close_worker (struct link_map *map, bool force) half-cooked objects. Temporarily disable exception handling, so that errors are fatal. */ if (imap->l_init_called) - { - /* When debugging print a message first. */ - if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS, - 0)) - _dl_debug_printf ("\ncalling fini: %s [%lu]\n\n", - imap->l_name, nsid); - - if (imap->l_info[DT_FINI_ARRAY] != NULL - || imap->l_info[DT_FINI] != NULL) - _dl_catch_exception (NULL, call_destructors, imap); - } + _dl_catch_exception (NULL, _dl_call_fini, imap); #ifdef SHARED /* Auditing checkpoint: we remove an object. */ diff --git a/elf/dl-fini.c b/elf/dl-fini.c index 030b1fcbcd..50ff94db16 100644 --- a/elf/dl-fini.c +++ b/elf/dl-fini.c @@ -21,11 +21,6 @@ #include #include - -/* Type of the constructor functions. */ -typedef void (*fini_t) (void); - - void _dl_fini (void) { @@ -116,38 +111,7 @@ _dl_fini (void) if (l->l_init_called) { - /* Make sure nothing happens if we are called twice. */ - l->l_init_called = 0; - - /* Is there a destructor function? */ - if (l->l_info[DT_FINI_ARRAY] != NULL - || (ELF_INITFINI && l->l_info[DT_FINI] != NULL)) - { - /* When debugging print a message first. */ - if (__builtin_expect (GLRO(dl_debug_mask) - & DL_DEBUG_IMPCALLS, 0)) - _dl_debug_printf ("\ncalling fini: %s [%lu]\n\n", - DSO_FILENAME (l->l_name), - ns); - - /* First see whether an array is given. */ - if (l->l_info[DT_FINI_ARRAY] != NULL) - { - ElfW(Addr) *array = - (ElfW(Addr) *) (l->l_addr - + l->l_info[DT_FINI_ARRAY]->d_un.d_ptr); - unsigned int i = (l->l_info[DT_FINI_ARRAYSZ]->d_un.d_val - / sizeof (ElfW(Addr))); - while (i-- > 0) - ((fini_t) array[i]) (); - } - - /* Next try the old-style destructor. */ - if (ELF_INITFINI && l->l_info[DT_FINI] != NULL) - DL_CALL_DT_FINI - (l, l->l_addr + l->l_info[DT_FINI]->d_un.d_ptr); - } - + _dl_call_fini (l); #ifdef SHARED /* Auditing checkpoint: another object closed. */ _dl_audit_objclose (l); diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h index 6b256b8388..c2627fced7 100644 --- a/sysdeps/generic/ldsodefs.h +++ b/sysdeps/generic/ldsodefs.h @@ -105,6 +105,9 @@ typedef struct link_map *lookup_t; DT_PREINIT_ARRAY. */ typedef void (*dl_init_t) (int, char **, char **); +/* Type of a constructor function, in DT_FINI, DT_FINI_ARRAY. */ +typedef void (*fini_t) (void); + /* On some architectures a pointer to a function is not just a pointer to the actual code of the function but rather an architecture specific descriptor. */ @@ -1048,6 +1051,11 @@ extern void _dl_init (struct link_map *main_map, int argc, char **argv, initializer functions have completed. */ extern void _dl_fini (void) attribute_hidden; +/* Invoke the DT_FINI_ARRAY and DT_FINI destructors for MAP, which + must be a struct link_map *. Can be used as an argument to + _dl_catch_exception. */ +void _dl_call_fini (void *map) attribute_hidden; + /* Sort array MAPS according to dependencies of the contained objects. If FORCE_FIRST, MAPS[0] keeps its place even if the dependencies say otherwise. */