1 /* 2 * Copyright (c) 2010 Konstantin Belousov <kib@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Neither the name of the author nor the names of any co-contributors 11 * may be used to endorse or promote products derived from this software 12 * without specific prior written permission. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include <sys/types.h> 30 #include <sys/mman.h> 31 #include <sys/resource.h> 32 #include <sys/sysctl.h> 33 #include <link.h> 34 #include <stddef.h> 35 #include "libc_private.h" 36 37 int __elf_phdr_match_addr(struct dl_phdr_info *, void *); 38 void __pthread_map_stacks_exec(void); 39 40 int 41 __elf_phdr_match_addr(struct dl_phdr_info *phdr_info, void *addr) 42 { 43 const Elf_Phdr *ph; 44 int i; 45 46 for (i = 0; i < phdr_info->dlpi_phnum; i++) { 47 ph = &phdr_info->dlpi_phdr[i]; 48 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_X) == 0) 49 continue; 50 if (phdr_info->dlpi_addr + ph->p_vaddr <= (uintptr_t)addr && 51 (uintptr_t)addr + sizeof(addr) < phdr_info->dlpi_addr + 52 ph->p_vaddr + ph->p_memsz) 53 break; 54 } 55 return (i != phdr_info->dlpi_phnum); 56 } 57 58 void 59 __libc_map_stacks_exec(void) 60 { 61 int mib[2]; 62 struct rlimit rlim; 63 u_long usrstack; 64 size_t len; 65 66 mib[0] = CTL_KERN; 67 mib[1] = KERN_USRSTACK; 68 len = sizeof(usrstack); 69 if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), &usrstack, &len, NULL, 0) 70 == -1) 71 return; 72 if (getrlimit(RLIMIT_STACK, &rlim) == -1) 73 return; 74 mprotect((void *)(uintptr_t)(usrstack - rlim.rlim_cur), 75 rlim.rlim_cur, _rtld_get_stack_prot()); 76 } 77 78 #pragma weak __pthread_map_stacks_exec 79 void 80 __pthread_map_stacks_exec(void) 81 { 82 83 ((void (*)(void))__libc_interposing[INTERPOS_map_stacks_exec])(); 84 } 85