| 1 | /* Verify that TLS access in separate thread in a dlopened library does not |
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| 2 | deadlock. |
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| 3 | Copyright (C) 2015-2024 Free Software Foundation, Inc. |
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| 4 | This file is part of the GNU C Library. |
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| 5 | |
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| 6 | The GNU C Library is free software; you can redistribute it and/or |
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| 7 | modify it under the terms of the GNU Lesser General Public |
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| 8 | License as published by the Free Software Foundation; either |
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| 9 | version 2.1 of the License, or (at your option) any later version. |
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| 10 | |
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| 11 | The GNU C Library is distributed in the hope that it will be useful, |
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| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 14 | Lesser General Public License for more details. |
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| 15 | |
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| 16 | You should have received a copy of the GNU Lesser General Public |
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| 17 | License along with the GNU C Library; if not, see |
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| 18 | <https://www.gnu.org/licenses/>. */ |
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| 19 | |
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| 20 | #include <dlfcn.h> |
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| 21 | |
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| 22 | /* When one dynamically loads a module, which spawns a thread to perform some |
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| 23 | activities, it could be possible that TLS storage is accessed for the first |
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| 24 | time in that thread. This results in an allocation request within the |
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| 25 | thread, which could result in an attempt to take the rtld load_lock. This |
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| 26 | is a problem because it would then deadlock with the dlopen (which owns the |
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| 27 | lock), if the main thread is waiting for the spawned thread to exit. We can |
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| 28 | at least ensure that this problem does not occur due to accesses within |
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| 29 | libc.so, by marking TLS variables within libc.so as IE. The problem of an |
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| 30 | arbitrary variable being accessed and constructed within such a thread still |
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| 31 | exists but this test case does not verify that. */ |
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| 32 | |
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| 33 | int |
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| 34 | do_test (void) |
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| 35 | { |
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| 36 | void *f = dlopen (file: "tst-join7mod.so" , RTLD_NOW | RTLD_GLOBAL); |
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| 37 | if (f) |
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| 38 | dlclose (handle: f); |
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| 39 | else |
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| 40 | return 1; |
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| 41 | |
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| 42 | return 0; |
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| 43 | } |
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| 44 | |
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| 45 | #define TEST_FUNCTION do_test () |
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| 46 | #include "../test-skeleton.c" |
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| 47 | |
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