1 /* 2 * Copyright (c) 1999-2000 Wichert Akkerman <wichert (at) cistron.nl> 3 * Copyright (c) 2002-2005 Roland McGrath <roland (at) redhat.com> 4 * Copyright (c) 2008 Jan Kratochvil <jan.kratochvil (at) redhat.com> 5 * Copyright (c) 2009-2013 Denys Vlasenko <dvlasenk (at) redhat.com> 6 * Copyright (c) 2006-2015 Dmitry V. Levin <ldv (at) altlinux.org> 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. The name of the author may not be used to endorse or promote products 18 * derived from this software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include "defs.h" 33 #include <sched.h> 34 #include <asm/unistd.h> 35 36 #ifndef CSIGNAL 37 # define CSIGNAL 0x000000ff 38 #endif 39 40 #include "xlat/clone_flags.h" 41 #include "xlat/setns_types.h" 42 #include "xlat/unshare_flags.h" 43 44 #if defined IA64 45 # define ARG_FLAGS 0 46 # define ARG_STACK 1 47 # define ARG_STACKSIZE (tcp->scno == __NR_clone2 ? 2 : -1) 48 # define ARG_PTID (tcp->scno == __NR_clone2 ? 3 : 2) 49 # define ARG_CTID (tcp->scno == __NR_clone2 ? 4 : 3) 50 # define ARG_TLS (tcp->scno == __NR_clone2 ? 5 : 4) 51 #elif defined S390 || defined S390X || defined CRISV10 || defined CRISV32 52 # define ARG_STACK 0 53 # define ARG_FLAGS 1 54 # define ARG_PTID 2 55 # define ARG_CTID 3 56 # define ARG_TLS 4 57 #elif defined X86_64 || defined X32 58 /* x86 personality processes have the last two arguments flipped. */ 59 # define ARG_FLAGS 0 60 # define ARG_STACK 1 61 # define ARG_PTID 2 62 # define ARG_CTID ((current_personality != 1) ? 3 : 4) 63 # define ARG_TLS ((current_personality != 1) ? 4 : 3) 64 #elif defined ALPHA || defined TILE || defined OR1K || defined RISCV 65 # define ARG_FLAGS 0 66 # define ARG_STACK 1 67 # define ARG_PTID 2 68 # define ARG_CTID 3 69 # define ARG_TLS 4 70 #else 71 # define ARG_FLAGS 0 72 # define ARG_STACK 1 73 # define ARG_PTID 2 74 # define ARG_TLS 3 75 # define ARG_CTID 4 76 #endif 77 78 static void 79 print_tls_arg(struct tcb *const tcp, const kernel_ulong_t addr) 80 { 81 #ifdef HAVE_STRUCT_USER_DESC 82 # if SUPPORTED_PERSONALITIES > 1 83 if (current_personality == 1) 84 # endif 85 { 86 print_user_desc(tcp, tcp->u_arg[ARG_TLS]); 87 } 88 # if SUPPORTED_PERSONALITIES > 1 89 else 90 # endif 91 #endif /* HAVE_STRUCT_USER_DESC */ 92 { 93 printaddr(tcp->u_arg[ARG_TLS]); 94 } 95 } 96 97 SYS_FUNC(clone) 98 { 99 if (exiting(tcp)) { 100 const char *sep = "|"; 101 kernel_ulong_t flags = tcp->u_arg[ARG_FLAGS]; 102 tprints("child_stack="); 103 printaddr(tcp->u_arg[ARG_STACK]); 104 tprints(", "); 105 #ifdef ARG_STACKSIZE 106 if (ARG_STACKSIZE != -1) 107 tprintf("stack_size=%#" PRI_klx ", ", 108 tcp->u_arg[ARG_STACKSIZE]); 109 #endif 110 tprints("flags="); 111 if (!printflags64(clone_flags, flags &~ CSIGNAL, NULL)) 112 sep = ""; 113 if ((flags & CSIGNAL) != 0) 114 tprintf("%s%s", sep, signame(flags & CSIGNAL)); 115 if ((flags & (CLONE_PARENT_SETTID|CLONE_CHILD_SETTID 116 |CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0) 117 return 0; 118 if (flags & CLONE_PARENT_SETTID) { 119 tprints(", parent_tidptr="); 120 printaddr(tcp->u_arg[ARG_PTID]); 121 } 122 if (flags & CLONE_SETTLS) { 123 tprints(", tls="); 124 print_tls_arg(tcp, tcp->u_arg[ARG_TLS]); 125 } 126 if (flags & (CLONE_CHILD_SETTID|CLONE_CHILD_CLEARTID)) { 127 tprints(", child_tidptr="); 128 printaddr(tcp->u_arg[ARG_CTID]); 129 } 130 } 131 /* TODO on syscall entry: 132 * We can clear CLONE_PTRACE here since it is an ancient hack 133 * to allow us to catch children, and we use another hack for that. 134 * But CLONE_PTRACE can conceivably be used by malicious programs 135 * to subvert us. By clearing this bit, we can defend against it: 136 * in untraced execution, CLONE_PTRACE should have no effect. 137 * 138 * We can also clear CLONE_UNTRACED, since it allows to start 139 * children outside of our control. At the moment 140 * I'm trying to figure out whether there is a *legitimate* 141 * use of this flag which we should respect. 142 */ 143 return 0; 144 } 145 146 SYS_FUNC(setns) 147 { 148 printfd(tcp, tcp->u_arg[0]); 149 tprints(", "); 150 printxval(setns_types, tcp->u_arg[1], "CLONE_NEW???"); 151 152 return RVAL_DECODED; 153 } 154 155 SYS_FUNC(unshare) 156 { 157 printflags64(unshare_flags, tcp->u_arg[0], "CLONE_???"); 158 return RVAL_DECODED; 159 } 160 161 SYS_FUNC(fork) 162 { 163 return RVAL_DECODED | RVAL_UDECIMAL; 164 } 165
