elf_utils.c revision 296732 
1/*
2 * Copyright (c) 2010 Konstantin Belousov <kib@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Neither the name of the author nor the names of any co-contributors
11 *    may be used to endorse or promote products derived from this software
12 *    without specific prior written permission.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: stable/10/lib/libc/gen/elf_utils.c 296732 2016-03-12 17:33:40Z kib $
27 */
28
29#include <sys/types.h>
30#include <sys/mman.h>
31#include <sys/resource.h>
32#include <sys/sysctl.h>
33#include <link.h>
34#include <stddef.h>
35#include "libc_private.h"
36
37int
38__elf_phdr_match_addr(struct dl_phdr_info *phdr_info, void *addr)
39{
40	const Elf_Phdr *ph;
41	int i;
42
43	for (i = 0; i < phdr_info->dlpi_phnum; i++) {
44		ph = &phdr_info->dlpi_phdr[i];
45		if (ph->p_type != PT_LOAD || (ph->p_flags & PF_X) == 0)
46			continue;
47		if (phdr_info->dlpi_addr + ph->p_vaddr <= (uintptr_t)addr &&
48		    (uintptr_t)addr + sizeof(addr) < phdr_info->dlpi_addr +
49		    ph->p_vaddr + ph->p_memsz)
50			break;
51	}
52	return (i != phdr_info->dlpi_phnum);
53}
54
55void
56__libc_map_stacks_exec(void)
57{
58	int mib[2];
59	struct rlimit rlim;
60	u_long usrstack;
61	size_t len;
62
63	mib[0] = CTL_KERN;
64	mib[1] = KERN_USRSTACK;
65	len = sizeof(usrstack);
66	if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), &usrstack, &len, NULL, 0)
67	    == -1)
68		return;
69	if (getrlimit(RLIMIT_STACK, &rlim) == -1)
70		return;
71	mprotect((void *)(uintptr_t)(usrstack - rlim.rlim_cur),
72	    rlim.rlim_cur, _rtld_get_stack_prot());
73}
74
75#pragma weak __pthread_map_stacks_exec
76void
77__pthread_map_stacks_exec(void)
78{
79
80	((void (*)(void))__libc_interposing[INTERPOS_map_stacks_exec])();
81}
82