xref: /freebsd/lib/libc/gen/elf_utils.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
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  * $FreeBSD$
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 
36 int
37 __elf_phdr_match_addr(struct dl_phdr_info *phdr_info, void *addr)
38 {
39 	const Elf_Phdr *ph;
40 	int i;
41 
42 	for (i = 0; i < phdr_info->dlpi_phnum; i++) {
43 		ph = &phdr_info->dlpi_phdr[i];
44 		if (ph->p_type != PT_LOAD || (ph->p_flags & PF_X) == 0)
45 			continue;
46 		if (phdr_info->dlpi_addr + ph->p_vaddr <= (uintptr_t)addr &&
47 		    (uintptr_t)addr + sizeof(addr) < phdr_info->dlpi_addr +
48 		    ph->p_vaddr + ph->p_memsz)
49 			break;
50 	}
51 	return (i != phdr_info->dlpi_phnum);
52 }
53 
54 #pragma weak __pthread_map_stacks_exec
55 void
56 __pthread_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