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
40 void __pthread_map_stacks_exec(void);
41 void __pthread_distribute_static_tls(size_t, void *, size_t, size_t);
42
43 int
__elf_phdr_match_addr(struct dl_phdr_info * phdr_info,void * addr)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
74 void
__libc_map_stacks_exec(void)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
99 void
__pthread_map_stacks_exec(void)100 __pthread_map_stacks_exec(void)
101 {
102
103 ((void (*)(void))__libc_interposing[INTERPOS_map_stacks_exec])();
104 }
105
106 void
__libc_distribute_static_tls(size_t offset,void * src,size_t len,size_t total_len)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
118 void
__pthread_distribute_static_tls(size_t offset,void * src,size_t len,size_t total_len)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