| 1 | /* Recursive locking implementation for the dynamic loader. NPTL version. |
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| 2 | Copyright (C) 2021-2024 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | /* Use the mutex implementation in libc (assuming PTHREAD_IN_LIBC). */ |
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| 20 | |
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| 21 | #include <assert.h> |
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| 22 | #include <first-versions.h> |
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| 23 | #include <ldsodefs.h> |
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| 24 | |
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| 25 | __typeof (pthread_mutex_lock) *___rtld_mutex_lock attribute_relro; |
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| 26 | __typeof (pthread_mutex_unlock) *___rtld_mutex_unlock attribute_relro; |
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| 27 | |
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| 28 | void |
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| 29 | __rtld_mutex_init (void) |
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| 30 | { |
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| 31 | /* There is an implicit assumption here that the lock counters are |
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| 32 | zero and this function is called while nothing is locked. For |
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| 33 | early initialization of the mutex functions this is true because |
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| 34 | it happens directly in dl_main in elf/rtld.c, and not some ELF |
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| 35 | constructor while holding loader locks. */ |
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| 36 | |
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| 37 | struct link_map *libc_map = GL (dl_ns)[LM_ID_BASE].libc_map; |
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| 38 | |
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| 39 | const ElfW(Sym) *sym |
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| 40 | = _dl_lookup_direct (map: libc_map, undef_name: "pthread_mutex_lock" , |
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| 41 | new_hash: 0x4f152227, /* dl_new_hash output. */ |
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| 42 | FIRST_VERSION_libc_pthread_mutex_lock_STRING, |
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| 43 | FIRST_VERSION_libc_pthread_mutex_lock_HASH); |
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| 44 | assert (sym != NULL); |
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| 45 | ___rtld_mutex_lock = DL_SYMBOL_ADDRESS (libc_map, sym); |
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| 46 | |
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| 47 | sym = _dl_lookup_direct (map: libc_map, undef_name: "pthread_mutex_unlock" , |
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| 48 | new_hash: 0x7dd7aaaa, /* dl_new_hash output. */ |
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| 49 | FIRST_VERSION_libc_pthread_mutex_unlock_STRING, |
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| 50 | FIRST_VERSION_libc_pthread_mutex_unlock_HASH); |
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| 51 | assert (sym != NULL); |
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| 52 | ___rtld_mutex_unlock = DL_SYMBOL_ADDRESS (libc_map, sym); |
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| 53 | } |
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| 54 | |
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