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 "libc_private.h" 38 39 int __elf_phdr_match_addr(struct dl_phdr_info *, void *); 40 void __pthread_map_stacks_exec(void); 41 42 int 43 __elf_phdr_match_addr(struct dl_phdr_info *phdr_info, void *addr) 44 { 45 const Elf_Phdr *ph; 46 int i; 47 48 for (i = 0; i < phdr_info->dlpi_phnum; i++) { 49 ph = &phdr_info->dlpi_phdr[i]; 50 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_X) == 0) 51 continue; 52 if (phdr_info->dlpi_addr + ph->p_vaddr <= (uintptr_t)addr && 53 (uintptr_t)addr + sizeof(addr) < phdr_info->dlpi_addr + 54 ph->p_vaddr + ph->p_memsz) 55 break; 56 } 57 return (i != phdr_info->dlpi_phnum); 58 } 59 60 void 61 __libc_map_stacks_exec(void) 62 { 63 int mib[2]; 64 struct rlimit rlim; 65 u_long usrstack; 66 size_t len; 67 68 mib[0] = CTL_KERN; 69 mib[1] = KERN_USRSTACK; 70 len = sizeof(usrstack); 71 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), &usrstack, &len, NULL, 0) 72 == -1) 73 return; 74 if (getrlimit(RLIMIT_STACK, &rlim) == -1) 75 return; 76 mprotect((void *)(uintptr_t)(usrstack - rlim.rlim_cur), 77 rlim.rlim_cur, _rtld_get_stack_prot()); 78 } 79 80 #pragma weak __pthread_map_stacks_exec 81 void 82 __pthread_map_stacks_exec(void) 83 { 84 85 ((void (*)(void))__libc_interposing[INTERPOS_map_stacks_exec])(); 86 } 87