1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 * $FreeBSD$ 29 */ 30 31 #include <sys/types.h> 32 #include <sys/mman.h> 33 #include <sys/resource.h> 34 #include <sys/sysctl.h> 35 #include <link.h> 36 #include <stddef.h> 37 #include <string.h> 38 #include "libc_private.h" 39 #include "static_tls.h" 40 41 void __pthread_map_stacks_exec(void); 42 void __pthread_distribute_static_tls(size_t, void *, size_t, size_t); 43 44 int 45 __elf_phdr_match_addr(struct dl_phdr_info *phdr_info, void *addr) 46 { 47 const Elf_Phdr *ph; 48 int i; 49 50 for (i = 0; i < phdr_info->dlpi_phnum; i++) { 51 ph = &phdr_info->dlpi_phdr[i]; 52 if (ph->p_type != PT_LOAD) 53 continue; 54 55 /* ELFv1 ABI for powerpc64 passes function descriptor 56 * pointers around, not function pointers. The function 57 * descriptors live in .opd, which is a non-executable segment. 58 * The PF_X check would therefore make all address checks fail, 59 * causing a crash in some instances. Don't skip over 60 * non-executable segments in the ELFv1 powerpc64 case. 61 */ 62 #if !defined(__powerpc64__) || (defined(_CALL_ELF) && _CALL_ELF == 2) 63 if ((ph->p_flags & PF_X) == 0) 64 continue; 65 #endif 66 67 if (phdr_info->dlpi_addr + ph->p_vaddr <= (uintptr_t)addr && 68 (uintptr_t)addr < phdr_info->dlpi_addr + 69 ph->p_vaddr + ph->p_memsz) 70 break; 71 } 72 return (i != phdr_info->dlpi_phnum); 73 } 74 75 void 76 __libc_map_stacks_exec(void) 77 { 78 int mib[2]; 79 struct rlimit rlim; 80 u_long usrstack; 81 size_t len; 82 83 mib[0] = CTL_KERN; 84 mib[1] = KERN_USRSTACK; 85 len = sizeof(usrstack); 86 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), &usrstack, &len, NULL, 0) 87 == -1) 88 return; 89 if (getrlimit(RLIMIT_STACK, &rlim) == -1) 90 return; 91 mprotect((void *)(uintptr_t)(usrstack - rlim.rlim_cur), 92 rlim.rlim_cur, _rtld_get_stack_prot()); 93 } 94 95 #pragma weak __pthread_map_stacks_exec 96 void 97 __pthread_map_stacks_exec(void) 98 { 99 100 ((void (*)(void))__libc_interposing[INTERPOS_map_stacks_exec])(); 101 } 102 103 void 104 __libc_distribute_static_tls(size_t offset, void *src, size_t len, 105 size_t total_len) 106 { 107 uintptr_t tlsbase; 108 109 tlsbase = _libc_get_static_tls_base(offset); 110 memcpy((void *)tlsbase, src, len); 111 memset((char *)tlsbase + len, 0, total_len - len); 112 } 113 114 #pragma weak __pthread_distribute_static_tls 115 void 116 __pthread_distribute_static_tls(size_t offset, void *src, size_t len, 117 size_t total_len) 118 { 119 120 ((void (*)(size_t, void *, size_t, size_t))__libc_interposing[ 121 INTERPOS_distribute_static_tls])(offset, src, len, total_len); 122 } 123