1 /* 2 * (MPSAFE) 3 * 4 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved. 5 * 6 * This code is derived from software contributed to The DragonFly Project 7 * by Matthew Dillon <dillon@backplane.com> 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 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 3. Neither the name of The DragonFly Project nor the names of its 20 * contributors may be used to endorse or promote products derived 21 * from this software without specific, prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 26 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 27 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 28 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 29 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 30 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 31 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 32 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 33 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/kernel.h> 40 #include <sys/sysproto.h> 41 #include <sys/exec.h> 42 #include <sys/imgact.h> 43 #include <sys/imgact_aout.h> 44 #include <sys/mman.h> 45 #include <sys/proc.h> 46 #include <sys/priv.h> 47 #include <sys/resourcevar.h> 48 #include <sys/sysent.h> 49 #include <sys/stat.h> 50 #include <sys/vnode.h> 51 #include <sys/inflate.h> 52 #include <sys/sysctl.h> 53 #include <sys/lock.h> 54 #include <sys/resident.h> 55 56 #include <vm/vm.h> 57 #include <vm/vm_param.h> 58 #include <vm/pmap.h> 59 #include <vm/vm_map.h> 60 #include <vm/vm_kern.h> 61 #include <vm/vm_extern.h> 62 63 #include <sys/sysref2.h> 64 65 static int exec_res_id = 0; 66 67 static TAILQ_HEAD(,vmresident) exec_res_list; 68 69 static MALLOC_DEFINE(M_EXEC_RES, "vmresident", "resident execs"); 70 71 /* lockmgr lock for protecting the exec_res_list */ 72 static struct lock exec_list_lock; 73 74 static void 75 vm_resident_init(void *__dummy) 76 { 77 lockinit(&exec_list_lock, "vmres", 0, 0); 78 TAILQ_INIT(&exec_res_list); 79 } 80 SYSINIT(vmres, SI_BOOT1_LOCK, SI_ORDER_ANY, vm_resident_init, 0); 81 82 static int 83 fill_xresident(struct vmresident *vr, struct xresident *in, struct thread *td) 84 { 85 struct stat st; 86 struct vnode *vrtmp; 87 int error = 0; 88 89 vrtmp = vr->vr_vnode; 90 91 in->res_entry_addr = vr->vr_entry_addr; 92 in->res_id = vr->vr_id; 93 if (vrtmp) { 94 char *freepath, *fullpath; 95 error = vn_fullpath(td->td_proc, vrtmp, &fullpath, &freepath, 0); 96 if (error != 0) { 97 /* could not retrieve cached path, return zero'ed string */ 98 bzero(in->res_file, MAXPATHLEN); 99 error = 0; 100 } else { 101 strlcpy(in->res_file, fullpath, sizeof(in->res_file)); 102 kfree(freepath, M_TEMP); 103 } 104 105 /* indicate that we are using the vnode */ 106 error = vget(vrtmp, LK_EXCLUSIVE); 107 if (error) 108 goto done; 109 110 /* retrieve underlying stat information and release vnode */ 111 error = vn_stat(vrtmp, &st, td->td_ucred); 112 vput(vrtmp); 113 if (error) 114 goto done; 115 116 in->res_stat = st; 117 } 118 119 done: 120 if (error) 121 kprintf("fill_xresident, error = %d\n", error); 122 return (error); 123 } 124 125 static int 126 sysctl_vm_resident(SYSCTL_HANDLER_ARGS) 127 { 128 struct vmresident *vmres; 129 struct thread *td; 130 int error; 131 int count; 132 133 /* only super-user should call this sysctl */ 134 td = req->td; 135 if ((priv_check(td, PRIV_VM_RESIDENT)) != 0) 136 return EPERM; 137 138 error = count = 0; 139 140 if (exec_res_id == 0) 141 return error; 142 143 /* client queried for number of resident binaries */ 144 if (!req->oldptr) 145 return SYSCTL_OUT(req, 0, exec_res_id); 146 147 lockmgr(&exec_list_lock, LK_SHARED); 148 149 TAILQ_FOREACH(vmres, &exec_res_list, vr_link) { 150 struct xresident xres; 151 error = fill_xresident(vmres, &xres, td); 152 if (error != 0) 153 break; 154 155 error = SYSCTL_OUT(req, (void *)&xres, 156 sizeof(struct xresident)); 157 if (error != 0) 158 break; 159 } 160 lockmgr(&exec_list_lock, LK_RELEASE); 161 162 return (error); 163 } 164 SYSCTL_PROC(_vm, OID_AUTO, resident, CTLTYPE_OPAQUE|CTLFLAG_RD, 0, 0, 165 sysctl_vm_resident, "S,xresident", "resident executables (sys/resident.h)"); 166 167 int 168 exec_resident_imgact(struct image_params *imgp) 169 { 170 struct vmresident *vmres; 171 172 /* 173 * resident image activator 174 */ 175 lockmgr(&exec_list_lock, LK_SHARED); 176 if ((vmres = imgp->vp->v_resident) == NULL) { 177 lockmgr(&exec_list_lock, LK_RELEASE); 178 return(-1); 179 } 180 atomic_add_int(&vmres->vr_refs, 1); 181 lockmgr(&exec_list_lock, LK_RELEASE); 182 183 /* 184 * We want to exec the new vmspace without holding the lock to 185 * improve concurrency. 186 */ 187 exec_new_vmspace(imgp, vmres->vr_vmspace); 188 imgp->resident = 1; 189 imgp->interpreted = 0; 190 imgp->proc->p_sysent = vmres->vr_sysent; 191 imgp->entry_addr = vmres->vr_entry_addr; 192 atomic_subtract_int(&vmres->vr_refs, 1); 193 194 return(0); 195 } 196 197 /* 198 * exec_sys_register(entry) 199 * 200 * Register ourselves for resident execution. Only root (i.e. a process with 201 * PRIV_VM_RESIDENT credentials) can do this. This 202 * will snapshot the vmspace and cause future exec's of the specified binary 203 * to use the snapshot directly rather then load & relocate a new copy. 204 * 205 * MPALMOSTSAFE 206 */ 207 int 208 sys_exec_sys_register(struct exec_sys_register_args *uap) 209 { 210 struct thread *td = curthread; 211 struct vmresident *vmres; 212 struct vnode *vp; 213 struct proc *p; 214 int error; 215 216 p = td->td_proc; 217 error = priv_check_cred(td->td_ucred, PRIV_VM_RESIDENT, 0); 218 if (error) 219 return(error); 220 221 if ((vp = p->p_textvp) == NULL) 222 return(ENOENT); 223 224 lockmgr(&exec_list_lock, LK_EXCLUSIVE); 225 226 if (vp->v_resident) { 227 lockmgr(&exec_list_lock, LK_RELEASE); 228 return(EEXIST); 229 } 230 231 vhold(vp); 232 vmres = kmalloc(sizeof(*vmres), M_EXEC_RES, M_WAITOK | M_ZERO); 233 vmres->vr_vnode = vp; 234 vmres->vr_sysent = p->p_sysent; 235 vmres->vr_id = ++exec_res_id; 236 vmres->vr_entry_addr = (intptr_t)uap->entry; 237 vmres->vr_vmspace = vmspace_fork(p->p_vmspace); /* XXX order */ 238 pmap_pinit2(vmspace_pmap(vmres->vr_vmspace)); 239 vp->v_resident = vmres; 240 241 TAILQ_INSERT_TAIL(&exec_res_list, vmres, vr_link); 242 lockmgr(&exec_list_lock, LK_RELEASE); 243 244 return(0); 245 } 246 247 /* 248 * exec_sys_unregister(id) 249 * 250 * Unregister the specified id. If an id of -1 is used unregister 251 * the registration associated with the current process. An id of -2 252 * unregisters everything. 253 * 254 * MPALMOSTSAFE 255 */ 256 int 257 sys_exec_sys_unregister(struct exec_sys_unregister_args *uap) 258 { 259 struct thread *td = curthread; 260 struct vmresident *vmres; 261 struct proc *p; 262 int error; 263 int id; 264 int count; 265 266 p = td->td_proc; 267 error = priv_check_cred(td->td_ucred, PRIV_VM_RESIDENT, 0); 268 if (error) 269 return(error); 270 271 /* 272 * If id is -1, unregister ourselves 273 */ 274 lockmgr(&exec_list_lock, LK_EXCLUSIVE); 275 276 if ((id = uap->id) == -1 && p->p_textvp && p->p_textvp->v_resident) 277 id = p->p_textvp->v_resident->vr_id; 278 279 /* 280 * Look for the registration 281 */ 282 error = ENOENT; 283 count = 0; 284 285 restart: 286 TAILQ_FOREACH(vmres, &exec_res_list, vr_link) { 287 if (id == -2 || vmres->vr_id == id) { 288 /* 289 * Check race against exec 290 */ 291 if (vmres->vr_refs) { 292 lockmgr(&exec_list_lock, LK_RELEASE); 293 tsleep(vmres, 0, "vmres", 1); 294 lockmgr(&exec_list_lock, LK_EXCLUSIVE); 295 goto restart; 296 } 297 298 /* 299 * Remove it 300 */ 301 TAILQ_REMOVE(&exec_res_list, vmres, vr_link); 302 if (vmres->vr_vnode) { 303 vmres->vr_vnode->v_resident = NULL; 304 vdrop(vmres->vr_vnode); 305 vmres->vr_vnode = NULL; 306 } 307 if (vmres->vr_vmspace) { 308 vmspace_rel(vmres->vr_vmspace); 309 vmres->vr_vmspace = NULL; 310 } 311 kfree(vmres, M_EXEC_RES); 312 exec_res_id--; 313 error = 0; 314 ++count; 315 goto restart; 316 } 317 } 318 lockmgr(&exec_list_lock, LK_RELEASE); 319 320 if (error == 0) 321 uap->sysmsg_result = count; 322 return(error); 323 } 324 325