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 35 #include <machine/tls.h> 36 37 #include <link.h> 38 #include <stddef.h> 39 #include <string.h> 40 41 #include "libc_private.h" 42 43 void __pthread_map_stacks_exec(void); 44 void __pthread_distribute_static_tls(size_t, void *, size_t, size_t); 45 46 int 47 __elf_phdr_match_addr(struct dl_phdr_info *phdr_info, void *addr) 48 { 49 const Elf_Phdr *ph; 50 int i; 51 52 for (i = 0; i < phdr_info->dlpi_phnum; i++) { 53 ph = &phdr_info->dlpi_phdr[i]; 54 if (ph->p_type != PT_LOAD) 55 continue; 56 57 /* ELFv1 ABI for powerpc64 passes function descriptor 58 * pointers around, not function pointers. The function 59 * descriptors live in .opd, which is a non-executable segment. 60 * The PF_X check would therefore make all address checks fail, 61 * causing a crash in some instances. Don't skip over 62 * non-executable segments in the ELFv1 powerpc64 case. 63 */ 64 #if !defined(__powerpc64__) || (defined(_CALL_ELF) && _CALL_ELF == 2) 65 if ((ph->p_flags & PF_X) == 0) 66 continue; 67 #endif 68 69 if (phdr_info->dlpi_addr + ph->p_vaddr <= (uintptr_t)addr && 70 (uintptr_t)addr < phdr_info->dlpi_addr + 71 ph->p_vaddr + ph->p_memsz) 72 break; 73 } 74 return (i != phdr_info->dlpi_phnum); 75 } 76 77 void 78 __libc_map_stacks_exec(void) 79 { 80 int mib[2]; 81 struct rlimit rlim; 82 u_long usrstack, stacksz; 83 size_t len; 84 85 if (_elf_aux_info(AT_USRSTACKBASE, &usrstack, sizeof(usrstack)) != 0) { 86 mib[0] = CTL_KERN; 87 mib[1] = KERN_USRSTACK; 88 len = sizeof(usrstack); 89 if (sysctl(mib, nitems(mib), &usrstack, &len, NULL, 0) == -1) 90 return; 91 } 92 if (_elf_aux_info(AT_USRSTACKLIM, &stacksz, sizeof(stacksz)) != 0) { 93 if (getrlimit(RLIMIT_STACK, &rlim) == -1) 94 return; 95 stacksz = rlim.rlim_cur; 96 } 97 mprotect((void *)(uintptr_t)(usrstack - stacksz), stacksz, 98 _rtld_get_stack_prot()); 99 } 100 101 #pragma weak __pthread_map_stacks_exec 102 void 103 __pthread_map_stacks_exec(void) 104 { 105 106 ((void (*)(void))__libc_interposing[INTERPOS_map_stacks_exec])(); 107 } 108 109 void 110 __libc_distribute_static_tls(size_t offset, void *src, size_t len, 111 size_t total_len) 112 { 113 char *tlsbase; 114 115 #ifdef TLS_VARIANT_I 116 tlsbase = (char *)_tcb_get() + offset; 117 #else 118 tlsbase = (char *)_tcb_get() - offset; 119 #endif 120 memcpy(tlsbase, src, len); 121 memset(tlsbase + len, 0, total_len - len); 122 } 123 124 #pragma weak __pthread_distribute_static_tls 125 void 126 __pthread_distribute_static_tls(size_t offset, void *src, size_t len, 127 size_t total_len) 128 { 129 130 ((void (*)(size_t, void *, size_t, size_t))__libc_interposing[ 131 INTERPOS_distribute_static_tls])(offset, src, len, total_len); 132 } 133