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 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 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 100 __pthread_map_stacks_exec(void) 101 { 102 103 ((void (*)(void))__libc_interposing[INTERPOS_map_stacks_exec])(); 104 } 105 106 void 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 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