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 34 #include <sched.h> 35 36 #ifndef CSIGNAL 37 # define CSIGNAL 0x000000ff 38 #endif 39 40 #include "xlat/clone_flags.h" 41 42 #if defined IA64 43 # define ARG_FLAGS 0 44 # define ARG_STACK 1 45 # define ARG_STACKSIZE (tcp->scno == SYS_clone2 ? 2 : -1) 46 # define ARG_PTID (tcp->scno == SYS_clone2 ? 3 : 2) 47 # define ARG_CTID (tcp->scno == SYS_clone2 ? 4 : 3) 48 # define ARG_TLS (tcp->scno == SYS_clone2 ? 5 : 4) 49 #elif defined S390 || defined S390X || defined CRISV10 || defined CRISV32 50 # define ARG_STACK 0 51 # define ARG_FLAGS 1 52 # define ARG_PTID 2 53 # define ARG_CTID 3 54 # define ARG_TLS 4 55 #elif defined X86_64 || defined X32 56 /* x86 personality processes have the last two arguments flipped. */ 57 # define ARG_FLAGS 0 58 # define ARG_STACK 1 59 # define ARG_PTID 2 60 # define ARG_CTID ((current_personality != 1) ? 3 : 4) 61 # define ARG_TLS ((current_personality != 1) ? 4 : 3) 62 #elif defined ALPHA || defined TILE || defined OR1K 63 # define ARG_FLAGS 0 64 # define ARG_STACK 1 65 # define ARG_PTID 2 66 # define ARG_CTID 3 67 # define ARG_TLS 4 68 #else 69 # define ARG_FLAGS 0 70 # define ARG_STACK 1 71 # define ARG_PTID 2 72 # define ARG_TLS 3 73 # define ARG_CTID 4 74 #endif 75 76 #if defined I386 || defined X86_64 || defined X32 77 extern void print_user_desc(struct tcb *, long); 78 #endif /* I386 || X86_64 || X32 */ 79 80 SYS_FUNC(clone) 81 { 82 if (exiting(tcp)) { 83 const char *sep = "|"; 84 unsigned long flags = tcp->u_arg[ARG_FLAGS]; 85 tprintf("child_stack=%#lx, ", tcp->u_arg[ARG_STACK]); 86 #ifdef ARG_STACKSIZE 87 if (ARG_STACKSIZE != -1) 88 tprintf("stack_size=%#lx, ", 89 tcp->u_arg[ARG_STACKSIZE]); 90 #endif 91 tprints("flags="); 92 if (!printflags(clone_flags, flags &~ CSIGNAL, NULL)) 93 sep = ""; 94 if ((flags & CSIGNAL) != 0) 95 tprintf("%s%s", sep, signame(flags & CSIGNAL)); 96 if ((flags & (CLONE_PARENT_SETTID|CLONE_CHILD_SETTID 97 |CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0) 98 return 0; 99 if (flags & CLONE_PARENT_SETTID) 100 tprintf(", parent_tidptr=%#lx", tcp->u_arg[ARG_PTID]); 101 if (flags & CLONE_SETTLS) { 102 #if defined I386 || defined X86_64 || defined X32 103 # ifndef I386 104 if (current_personality == 1) 105 # endif 106 { 107 tprints(", tls="); 108 print_user_desc(tcp, tcp->u_arg[ARG_TLS]); 109 } 110 # ifndef I386 111 else 112 # endif 113 #endif /* I386 || X86_64 || X32 */ 114 tprintf(", tls=%#lx", tcp->u_arg[ARG_TLS]); 115 } 116 if (flags & (CLONE_CHILD_SETTID|CLONE_CHILD_CLEARTID)) 117 tprintf(", child_tidptr=%#lx", tcp->u_arg[ARG_CTID]); 118 } 119 /* TODO on syscall entry: 120 * We can clear CLONE_PTRACE here since it is an ancient hack 121 * to allow us to catch children, and we use another hack for that. 122 * But CLONE_PTRACE can conceivably be used by malicious programs 123 * to subvert us. By clearing this bit, we can defend against it: 124 * in untraced execution, CLONE_PTRACE should have no effect. 125 * 126 * We can also clear CLONE_UNTRACED, since it allows to start 127 * children outside of our control. At the moment 128 * I'm trying to figure out whether there is a *legitimate* 129 * use of this flag which we should respect. 130 */ 131 return 0; 132 } 133 134 SYS_FUNC(setns) 135 { 136 printfd(tcp, tcp->u_arg[0]); 137 tprints(", "); 138 printflags(clone_flags, tcp->u_arg[1], "CLONE_???"); 139 140 return RVAL_DECODED; 141 } 142 143 SYS_FUNC(unshare) 144 { 145 printflags(clone_flags, tcp->u_arg[0], "CLONE_???"); 146 return RVAL_DECODED; 147 } 148 149 SYS_FUNC(fork) 150 { 151 return RVAL_DECODED | RVAL_UDECIMAL; 152 } 153
