1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2010 Konstantin Belousov <kib@freebsd.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Neither the name of the author nor the names of any co-contributors
13 *    may be used to endorse or promote products derived from this software
14 *    without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/param.h>
30#include <sys/auxv.h>
31#include <sys/mman.h>
32#include <sys/resource.h>
33#include <sys/sysctl.h>
34#include <link.h>
35#include <stddef.h>
36#include <string.h>
37#include "libc_private.h"
38#include "static_tls.h"
39
40void __pthread_map_stacks_exec(void);
41void __pthread_distribute_static_tls(size_t, void *, size_t, size_t);
42
43int
44__elf_phdr_match_addr(struct dl_phdr_info *phdr_info, void *addr)
45{
46	const Elf_Phdr *ph;
47	int i;
48
49	for (i = 0; i < phdr_info->dlpi_phnum; i++) {
50		ph = &phdr_info->dlpi_phdr[i];
51		if (ph->p_type != PT_LOAD)
52			continue;
53
54		/* ELFv1 ABI for powerpc64 passes function descriptor
55		 * pointers around, not function pointers.  The function
56		 * descriptors live in .opd, which is a non-executable segment.
57		 * The PF_X check would therefore make all address checks fail,
58		 * causing a crash in some instances.  Don't skip over
59		 * non-executable segments in the ELFv1 powerpc64 case.
60		 */
61#if !defined(__powerpc64__) || (defined(_CALL_ELF) && _CALL_ELF == 2)
62		if ((ph->p_flags & PF_X) == 0)
63			continue;
64#endif
65
66		if (phdr_info->dlpi_addr + ph->p_vaddr <= (uintptr_t)addr &&
67		    (uintptr_t)addr < phdr_info->dlpi_addr +
68		    ph->p_vaddr + ph->p_memsz)
69			break;
70	}
71	return (i != phdr_info->dlpi_phnum);
72}
73
74void
75__libc_map_stacks_exec(void)
76{
77	int mib[2];
78	struct rlimit rlim;
79	u_long usrstack, stacksz;
80	size_t len;
81
82	if (_elf_aux_info(AT_USRSTACKBASE, &usrstack, sizeof(usrstack)) != 0) {
83		mib[0] = CTL_KERN;
84		mib[1] = KERN_USRSTACK;
85		len = sizeof(usrstack);
86		if (sysctl(mib, nitems(mib), &usrstack, &len, NULL, 0) == -1)
87			return;
88	}
89	if (_elf_aux_info(AT_USRSTACKLIM, &stacksz, sizeof(stacksz)) != 0) {
90		if (getrlimit(RLIMIT_STACK, &rlim) == -1)
91			return;
92		stacksz = rlim.rlim_cur;
93	}
94	mprotect((void *)(uintptr_t)(usrstack - stacksz), stacksz,
95	    _rtld_get_stack_prot());
96}
97
98#pragma weak __pthread_map_stacks_exec
99void
100__pthread_map_stacks_exec(void)
101{
102
103	((void (*)(void))__libc_interposing[INTERPOS_map_stacks_exec])();
104}
105
106void
107__libc_distribute_static_tls(size_t offset, void *src, size_t len,
108    size_t total_len)
109{
110	uintptr_t tlsbase;
111
112	tlsbase = _libc_get_static_tls_base(offset);
113	memcpy((void *)tlsbase, src, len);
114	memset((char *)tlsbase + len, 0, total_len - len);
115}
116
117#pragma weak __pthread_distribute_static_tls
118void
119__pthread_distribute_static_tls(size_t offset, void *src, size_t len,
120    size_t total_len)
121{
122
123	((void (*)(size_t, void *, size_t, size_t))__libc_interposing[
124	    INTERPOS_distribute_static_tls])(offset, src, len, total_len);
125}
126