1 /* $NetBSD: linux_exec.c,v 1.72 2004/08/08 19:52:37 jdolecek Exp $ */ 2 3 /*- 4 * Copyright (c) 1994, 1995, 1998, 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas, Frank van der Linden, Eric Haszlakiewicz and 9 * Thor Lancelot Simon. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 #include <sys/cdefs.h> 41 __KERNEL_RCSID(0, "$NetBSD: linux_exec.c,v 1.72 2004/08/08 19:52:37 jdolecek Exp $"); 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/kernel.h> 46 #include <sys/proc.h> 47 #include <sys/malloc.h> 48 #include <sys/namei.h> 49 #include <sys/vnode.h> 50 #include <sys/mount.h> 51 #include <sys/exec.h> 52 #include <sys/exec_elf.h> 53 54 #include <sys/mman.h> 55 #include <sys/sa.h> 56 #include <sys/syscallargs.h> 57 58 #include <machine/cpu.h> 59 #include <machine/reg.h> 60 61 #include <compat/linux/common/linux_types.h> 62 #include <compat/linux/common/linux_signal.h> 63 #include <compat/linux/common/linux_util.h> 64 #include <compat/linux/common/linux_exec.h> 65 #include <compat/linux/common/linux_machdep.h> 66 67 #include <compat/linux/linux_syscallargs.h> 68 #include <compat/linux/linux_syscall.h> 69 #include <compat/linux/common/linux_misc.h> 70 #include <compat/linux/common/linux_errno.h> 71 #include <compat/linux/common/linux_emuldata.h> 72 73 extern struct sysent linux_sysent[]; 74 extern const char * const linux_syscallnames[]; 75 extern char linux_sigcode[], linux_esigcode[]; 76 77 static void linux_e_proc_exec __P((struct proc *, struct exec_package *)); 78 static void linux_e_proc_fork __P((struct proc *, struct proc *, int)); 79 static void linux_e_proc_exit __P((struct proc *)); 80 static void linux_e_proc_init __P((struct proc *, struct proc *, int)); 81 82 /* 83 * Execve(2). Just check the alternate emulation path, and pass it on 84 * to the NetBSD execve(). 85 */ 86 int 87 linux_sys_execve(l, v, retval) 88 struct lwp *l; 89 void *v; 90 register_t *retval; 91 { 92 struct linux_sys_execve_args /* { 93 syscallarg(const char *) path; 94 syscallarg(char **) argv; 95 syscallarg(char **) envp; 96 } */ *uap = v; 97 struct proc *p = l->l_proc; 98 struct sys_execve_args ap; 99 caddr_t sg; 100 101 sg = stackgap_init(p, 0); 102 CHECK_ALT_EXIST(p, &sg, SCARG(uap, path)); 103 104 SCARG(&ap, path) = SCARG(uap, path); 105 SCARG(&ap, argp) = SCARG(uap, argp); 106 SCARG(&ap, envp) = SCARG(uap, envp); 107 108 return sys_execve(l, &ap, retval); 109 } 110 111 /* 112 * Emulation switch. 113 */ 114 115 struct uvm_object *emul_linux_object; 116 117 const struct emul emul_linux = { 118 "linux", 119 "/emul/linux", 120 #ifndef __HAVE_MINIMAL_EMUL 121 0, 122 (int*)native_to_linux_errno, 123 LINUX_SYS_syscall, 124 LINUX_SYS_NSYSENT, 125 #endif 126 linux_sysent, 127 linux_syscallnames, 128 linux_sendsig, 129 linux_trapsignal, 130 NULL, 131 linux_sigcode, 132 linux_esigcode, 133 &emul_linux_object, 134 linux_setregs, 135 linux_e_proc_exec, 136 linux_e_proc_fork, 137 linux_e_proc_exit, 138 NULL, 139 NULL, 140 #ifdef __HAVE_SYSCALL_INTERN 141 linux_syscall_intern, 142 #else 143 #error Implement __HAVE_SYSCALL_INTERN for this platform 144 #endif 145 NULL, 146 NULL, 147 }; 148 149 static void 150 linux_e_proc_init(p, parent, forkflags) 151 struct proc *p, *parent; 152 int forkflags; 153 { 154 struct linux_emuldata *e = p->p_emuldata; 155 struct linux_emuldata_shared *s; 156 157 if (!e) { 158 /* allocate new Linux emuldata */ 159 MALLOC(e, void *, sizeof(struct linux_emuldata), 160 M_EMULDATA, M_WAITOK); 161 } else { 162 e->s->refs--; 163 if (e->s->refs == 0) 164 FREE(e->s, M_EMULDATA); 165 } 166 167 memset(e, '\0', sizeof(struct linux_emuldata)); 168 169 if (forkflags & FORK_SHAREVM) { 170 struct linux_emuldata *e2 = parent->p_emuldata; 171 s = e2->s; 172 s->refs++; 173 } else { 174 struct vmspace *vm; 175 176 MALLOC(s, void *, sizeof(struct linux_emuldata_shared), 177 M_EMULDATA, M_WAITOK); 178 s->refs = 1; 179 180 /* 181 * Set the process idea of the break to the real value. 182 * For fork, we use parent's vmspace since our's 183 * is not setup at the time of this call and is going 184 * to be copy of parent's anyway. For exec, just 185 * use our own vmspace. 186 */ 187 vm = (parent) ? parent->p_vmspace : p->p_vmspace; 188 s->p_break = vm->vm_daddr + ctob(vm->vm_dsize); 189 190 } 191 192 e->s = s; 193 p->p_emuldata = e; 194 } 195 196 /* 197 * Allocate new per-process structures. Called when executing Linux 198 * process. We can reuse the old emuldata - if it's not null, 199 * the executed process is of same emulation as original forked one. 200 */ 201 static void 202 linux_e_proc_exec(p, epp) 203 struct proc *p; 204 struct exec_package *epp; 205 { 206 /* exec, use our vmspace */ 207 linux_e_proc_init(p, NULL, 0); 208 } 209 210 /* 211 * Emulation per-process exit hook. 212 */ 213 static void 214 linux_e_proc_exit(p) 215 struct proc *p; 216 { 217 struct linux_emuldata *e = p->p_emuldata; 218 219 /* free Linux emuldata and set the pointer to null */ 220 e->s->refs--; 221 if (e->s->refs == 0) 222 FREE(e->s, M_EMULDATA); 223 FREE(e, M_EMULDATA); 224 p->p_emuldata = NULL; 225 } 226 227 /* 228 * Emulation fork hook. 229 */ 230 static void 231 linux_e_proc_fork(p, parent, forkflags) 232 struct proc *p, *parent; 233 int forkflags; 234 { 235 /* 236 * The new process might share some vmspace-related stuff 237 * with parent, depending on fork flags (CLONE_VM et.al). 238 * Force allocation of new base emuldata, and share the 239 * VM-related parts only if necessary. 240 */ 241 p->p_emuldata = NULL; 242 linux_e_proc_init(p, parent, forkflags); 243 } 244