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3d2cf95af1
This change also fixes a bug with gettid() being incorrect after fork(). We now implement the ENOENT behavior for getauxval(). The getuid() etc. system calls are now faster too. Plus issetugid() will work on BSDs.
43 lines
2.5 KiB
C
43 lines
2.5 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/calls/_getauxval.internal.h"
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#include "libc/runtime/runtime.h"
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/**
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* Returns auxiliary value, or zero if kernel didn't provide it.
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*
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* This function is typically regarded as a libc implementation detail;
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* thus, the source code is the documentation.
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*
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* @param at is `AT_...` search key
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* @return true if value was found
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* @see libc/sysv/consts.sh
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* @see System Five Application Binary Interface § 3.4.3
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* @error ENOENT when value not found
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* @asyncsignalsafe
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*/
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struct AuxiliaryValue _getauxval(unsigned long at) {
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unsigned long *ap;
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for (ap = __auxv; ap[0]; ap += 2) {
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if (at == ap[0]) {
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return (struct AuxiliaryValue){ap[1], true};
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}
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}
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return (struct AuxiliaryValue){0, false};
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}
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