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/sysmsg.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/sysctl.h> 52 #include <sys/lock.h> 53 #include <sys/resident.h> 54 #include <sys/malloc.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 static int exec_res_id = 0; 64 65 static TAILQ_HEAD(,vmresident) exec_res_list; 66 67 static MALLOC_DEFINE(M_EXEC_RES, "vmresident", "resident execs"); 68 69 /* lockmgr lock for protecting the exec_res_list */ 70 static struct lock exec_list_lock; 71 72 static void 73 vm_resident_init(void *__dummy) 74 { 75 lockinit(&exec_list_lock, "vmres", 0, 0); 76 TAILQ_INIT(&exec_res_list); 77 } 78 SYSINIT(vmres, SI_BOOT1_LOCK, SI_ORDER_ANY, vm_resident_init, 0); 79 80 static int 81 fill_xresident(struct vmresident *vr, struct xresident *in, struct thread *td) 82 { 83 struct stat st; 84 struct vnode *vrtmp; 85 int error = 0; 86 87 vrtmp = vr->vr_vnode; 88 89 in->res_entry_addr = vr->vr_entry_addr; 90 in->res_id = vr->vr_id; 91 if (vrtmp) { 92 char *freepath, *fullpath; 93 error = vn_fullpath(td->td_proc, vrtmp, &fullpath, &freepath, 0); 94 if (error != 0) { 95 /* could not retrieve cached path, return zero'ed string */ 96 bzero(in->res_file, MAXPATHLEN); 97 error = 0; 98 } else { 99 strlcpy(in->res_file, fullpath, sizeof(in->res_file)); 100 kfree(freepath, M_TEMP); 101 } 102 103 /* indicate that we are using the vnode */ 104 error = vget(vrtmp, LK_EXCLUSIVE); 105 if (error) 106 goto done; 107 108 /* retrieve underlying stat information and release vnode */ 109 error = vn_stat(vrtmp, &st, td->td_ucred); 110 vput(vrtmp); 111 if (error) 112 goto done; 113 114 in->res_stat = st; 115 } 116 117 done: 118 if (error) 119 kprintf("fill_xresident, error = %d\n", error); 120 return (error); 121 } 122 123 static int 124 sysctl_vm_resident(SYSCTL_HANDLER_ARGS) 125 { 126 struct vmresident *vmres; 127 struct thread *td; 128 int error; 129 int count; 130 131 /* only super-user should call this sysctl */ 132 td = req->td; 133 if ((priv_check(td, PRIV_VM_RESIDENT)) != 0) 134 return EPERM; 135 136 error = count = 0; 137 138 if (exec_res_id == 0) 139 return error; 140 141 /* client queried for number of resident binaries */ 142 if (!req->oldptr) 143 return SYSCTL_OUT(req, 0, exec_res_id); 144 145 lockmgr(&exec_list_lock, LK_SHARED); 146 147 TAILQ_FOREACH(vmres, &exec_res_list, vr_link) { 148 struct xresident xres; 149 error = fill_xresident(vmres, &xres, td); 150 if (error != 0) 151 break; 152 153 error = SYSCTL_OUT(req, (void *)&xres, 154 sizeof(struct xresident)); 155 if (error != 0) 156 break; 157 } 158 lockmgr(&exec_list_lock, LK_RELEASE); 159 160 return (error); 161 } 162 SYSCTL_PROC(_vm, OID_AUTO, resident, CTLTYPE_OPAQUE|CTLFLAG_RD, 0, 0, 163 sysctl_vm_resident, "S,xresident", "resident executables (sys/resident.h)"); 164 165 int 166 exec_resident_imgact(struct image_params *imgp) 167 { 168 struct vmresident *vmres; 169 170 /* 171 * resident image activator 172 */ 173 lockmgr(&exec_list_lock, LK_SHARED); 174 if ((vmres = imgp->vp->v_resident) == NULL) { 175 lockmgr(&exec_list_lock, LK_RELEASE); 176 return(-1); 177 } 178 atomic_add_int(&vmres->vr_refs, 1); 179 lockmgr(&exec_list_lock, LK_RELEASE); 180 181 /* 182 * We want to exec the new vmspace without holding the lock to 183 * improve concurrency. 184 */ 185 exec_new_vmspace(imgp, vmres->vr_vmspace); 186 imgp->resident = 1; 187 imgp->interpreted = 0; 188 imgp->proc->p_sysent = vmres->vr_sysent; 189 imgp->entry_addr = vmres->vr_entry_addr; 190 atomic_subtract_int(&vmres->vr_refs, 1); 191 192 return(0); 193 } 194 195 /* 196 * exec_sys_register(entry) 197 * 198 * Register ourselves for resident execution. Only root (i.e. a process with 199 * PRIV_VM_RESIDENT credentials) can do this. This 200 * will snapshot the vmspace and cause future exec's of the specified binary 201 * to use the snapshot directly rather then load & relocate a new copy. 202 * 203 * MPALMOSTSAFE 204 */ 205 int 206 sys_exec_sys_register(struct sysmsg *sysmsg, 207 const struct exec_sys_register_args *uap) 208 { 209 struct thread *td = curthread; 210 struct vmresident *vmres; 211 struct vnode *vp; 212 struct proc *p; 213 int error; 214 215 p = td->td_proc; 216 error = priv_check_cred(td->td_ucred, PRIV_VM_RESIDENT, 0); 217 if (error) 218 return(error); 219 220 if ((vp = p->p_textvp) == NULL) 221 return(ENOENT); 222 223 lockmgr(&exec_list_lock, LK_EXCLUSIVE); 224 225 if (vp->v_resident) { 226 lockmgr(&exec_list_lock, LK_RELEASE); 227 return(EEXIST); 228 } 229 230 vhold(vp); 231 vmres = kmalloc(sizeof(*vmres), M_EXEC_RES, M_WAITOK | M_ZERO); 232 vmres->vr_vnode = vp; 233 vmres->vr_sysent = p->p_sysent; 234 vmres->vr_id = ++exec_res_id; 235 vmres->vr_entry_addr = (intptr_t)uap->entry; 236 vmres->vr_vmspace = vmspace_fork(p->p_vmspace, NULL, NULL); /* XXX order */ 237 pmap_pinit2(vmspace_pmap(vmres->vr_vmspace)); 238 vp->v_resident = vmres; 239 240 TAILQ_INSERT_TAIL(&exec_res_list, vmres, vr_link); 241 lockmgr(&exec_list_lock, LK_RELEASE); 242 243 return(0); 244 } 245 246 /* 247 * exec_sys_unregister(id) 248 * 249 * Unregister the specified id. If an id of -1 is used unregister 250 * the registration associated with the current process. An id of -2 251 * unregisters everything. 252 * 253 * MPALMOSTSAFE 254 */ 255 int 256 sys_exec_sys_unregister(struct sysmsg *sysmsg, 257 const 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 sysmsg->sysmsg_result = count; 322 return(error); 323 } 324 325