diff options
Diffstat (limited to 'libc/stdlib/atexit.c')
| -rw-r--r-- | libc/stdlib/atexit.c | 209 |
1 files changed, 0 insertions, 209 deletions
diff --git a/libc/stdlib/atexit.c b/libc/stdlib/atexit.c deleted file mode 100644 index 5bf82ba..0000000 --- a/libc/stdlib/atexit.c +++ /dev/null @@ -1,209 +0,0 @@ -/* $OpenBSD: atexit.c,v 1.14 2007/09/05 20:47:47 chl Exp $ */ -/* - * Copyright (c) 2002 Daniel Hartmeier - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * - * - Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * - Redistributions in binary form must reproduce the above - * copyright notice, this list of conditions and the following - * disclaimer in the documentation and/or other materials provided - * with the distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS - * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE - * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, - * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; - * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER - * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN - * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE - * POSSIBILITY OF SUCH DAMAGE. - * - */ - -#include <sys/types.h> -#include <sys/mman.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> -#include "atexit.h" -#include "thread_private.h" - -int __atexit_invalid = 1; -struct atexit *__atexit; - -/* - * Function pointers are stored in a linked list of pages. The list - * is initially empty, and pages are allocated on demand. The first - * function pointer in the first allocated page (the last one in - * the linked list) is reserved for the cleanup function. - * - * Outside the following functions, all pages are mprotect()'ed - * to prevent unintentional/malicious corruption. - */ - -/* - * Register a function to be performed at exit or when a shared object - * with the given dso handle is unloaded dynamically. Also used as - * the backend for atexit(). For more info on this API, see: - * - * http://www.codesourcery.com/cxx-abi/abi.html#dso-dtor - */ -int -__cxa_atexit(void (*func)(void *), void *arg, void *dso) -{ - struct atexit *p = __atexit; - struct atexit_fn *fnp; - int pgsize = getpagesize(); - int ret = -1; - - if (pgsize < (int)sizeof(*p)) - return (-1); - _ATEXIT_LOCK(); - p = __atexit; - if (p != NULL) { - if (p->ind + 1 >= p->max) - p = NULL; - else if (mprotect(p, pgsize, PROT_READ | PROT_WRITE)) - goto unlock; - } - if (p == NULL) { - p = mmap(NULL, pgsize, PROT_READ | PROT_WRITE, - MAP_ANON | MAP_PRIVATE, -1, 0); - if (p == MAP_FAILED) - goto unlock; - if (__atexit == NULL) { - memset(&p->fns[0], 0, sizeof(p->fns[0])); - p->ind = 1; - } else - p->ind = 0; - p->max = (pgsize - ((char *)&p->fns[0] - (char *)p)) / - sizeof(p->fns[0]); - p->next = __atexit; - __atexit = p; - if (__atexit_invalid) - __atexit_invalid = 0; - } - fnp = &p->fns[p->ind++]; - fnp->fn_ptr.cxa_func = func; - fnp->fn_arg = arg; - fnp->fn_dso = dso; - if (mprotect(p, pgsize, PROT_READ)) - goto unlock; - ret = 0; -unlock: - _ATEXIT_UNLOCK(); - return (ret); -} - -/* - * Register a function to be performed at exit. - */ -int -atexit(void (*func)(void)) -{ - return (__cxa_atexit((void (*)(void *))func, NULL, NULL)); -} - -/* - * Call all handlers registered with __cxa_atexit() for the shared - * object owning 'dso'. - * Note: if 'dso' is NULL, then all remaining handlers are called. - */ -void -__cxa_finalize(void *dso) -{ - struct atexit *p, *q; - struct atexit_fn fn; - int n, pgsize = getpagesize(); - static int call_depth; - - if (__atexit_invalid) - return; - - call_depth++; - - for (p = __atexit; p != NULL; p = p->next) { - for (n = p->ind; --n >= 0;) { - if (p->fns[n].fn_ptr.cxa_func == NULL) - continue; /* already called */ - if (dso != NULL && dso != p->fns[n].fn_dso) - continue; /* wrong DSO */ - - /* - * Mark handler as having been already called to avoid - * dupes and loops, then call the appropriate function. - */ - fn = p->fns[n]; - if (mprotect(p, pgsize, PROT_READ | PROT_WRITE) == 0) { - p->fns[n].fn_ptr.cxa_func = NULL; - mprotect(p, pgsize, PROT_READ); - } - if (dso != NULL) - (*fn.fn_ptr.cxa_func)(fn.fn_arg); - else - (*fn.fn_ptr.std_func)(); - } - } - - /* - * If called via exit(), unmap the pages since we have now run - * all the handlers. We defer this until calldepth == 0 so that - * we don't unmap things prematurely if called recursively. - */ - if (dso == NULL && --call_depth == 0) { - for (p = __atexit; p != NULL; ) { - q = p; - p = p->next; - munmap(q, pgsize); - } - __atexit = NULL; - } -} - -/* - * Register the cleanup function - */ -void -__atexit_register_cleanup(void (*func)(void)) -{ - struct atexit *p; - int pgsize = getpagesize(); - - if (pgsize < (int)sizeof(*p)) - return; - _ATEXIT_LOCK(); - p = __atexit; - while (p != NULL && p->next != NULL) - p = p->next; - if (p == NULL) { - p = mmap(NULL, pgsize, PROT_READ | PROT_WRITE, - MAP_ANON | MAP_PRIVATE, -1, 0); - if (p == MAP_FAILED) - goto unlock; - p->ind = 1; - p->max = (pgsize - ((char *)&p->fns[0] - (char *)p)) / - sizeof(p->fns[0]); - p->next = NULL; - __atexit = p; - if (__atexit_invalid) - __atexit_invalid = 0; - } else { - if (mprotect(p, pgsize, PROT_READ | PROT_WRITE)) - goto unlock; - } - p->fns[0].fn_ptr.std_func = func; - p->fns[0].fn_arg = NULL; - p->fns[0].fn_dso = NULL; - mprotect(p, pgsize, PROT_READ); -unlock: - _ATEXIT_UNLOCK(); -} |