| 1 | /* Copyright (C) 1992-2022 Free Software Foundation, Inc. |
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| 2 | This file is part of the GNU C Library. |
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| 3 | |
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| 4 | The GNU C Library is free software; you can redistribute it and/or |
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| 5 | modify it under the terms of the GNU Lesser General Public |
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| 6 | License as published by the Free Software Foundation; either |
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| 7 | version 2.1 of the License, or (at your option) any later version. |
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| 8 | |
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| 9 | The GNU C Library is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 12 | Lesser General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU Lesser General Public |
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| 15 | License along with the GNU C Library; if not, see |
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| 16 | <https://www.gnu.org/licenses/>. */ |
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| 17 | |
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| 18 | #include <errno.h> |
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| 19 | #include <hurd.h> |
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| 20 | #include <hurd/signal.h> |
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| 21 | |
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| 22 | /* Run signals handlers on the stack specified by SS (if not NULL). |
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| 23 | If OSS is not NULL, it is filled in with the old signal stack status. */ |
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| 24 | int |
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| 25 | __sigaltstack (const stack_t *argss, stack_t *oss) |
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| 26 | { |
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| 27 | struct hurd_sigstate *s; |
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| 28 | stack_t ss, old; |
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| 29 | |
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| 30 | /* Fault before taking any locks. */ |
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| 31 | if (argss != NULL) |
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| 32 | ss = *argss; |
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| 33 | if (oss != NULL) |
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| 34 | *(volatile stack_t *) oss = *oss; |
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| 35 | |
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| 36 | s = _hurd_self_sigstate (); |
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| 37 | __spin_lock (&s->lock); |
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| 38 | |
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| 39 | if (argss != NULL |
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| 40 | && (ss.ss_flags & SS_DISABLE) |
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| 41 | && (s->sigaltstack.ss_flags & SS_ONSTACK)) |
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| 42 | { |
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| 43 | /* Can't disable a stack that is in use. */ |
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| 44 | __spin_unlock (&s->lock); |
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| 45 | errno = EINVAL; |
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| 46 | return -1; |
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| 47 | } |
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| 48 | |
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| 49 | old = s->sigaltstack; |
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| 50 | |
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| 51 | if (argss != NULL) |
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| 52 | s->sigaltstack = ss; |
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| 53 | |
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| 54 | __spin_unlock (&s->lock); |
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| 55 | |
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| 56 | if (oss != NULL) |
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| 57 | *oss = old; |
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| 58 | |
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| 59 | return 0; |
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| 60 | } |
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| 61 | libc_hidden_def (__sigaltstack) |
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| 62 | weak_alias (__sigaltstack, sigaltstack) |
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| 63 | |
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