procfs_subr.c revision 1.36.2.2
1 /* $NetBSD: procfs_subr.c,v 1.36.2.2 2001/04/09 01:58:09 nathanw Exp $ */ 2 3 /* 4 * Copyright (c) 1994 Christopher G. Demetriou. All rights reserved. 5 * Copyright (c) 1993 Jan-Simon Pendry 6 * Copyright (c) 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * Jan-Simon Pendry. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)procfs_subr.c 8.6 (Berkeley) 5/14/95 41 */ 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/time.h> 46 #include <sys/kernel.h> 47 #include <sys/proc.h> 48 #include <sys/vnode.h> 49 #include <sys/malloc.h> 50 #include <sys/stat.h> 51 52 #include <miscfs/procfs/procfs.h> 53 54 void procfs_hashins __P((struct pfsnode *)); 55 void procfs_hashrem __P((struct pfsnode *)); 56 struct vnode *procfs_hashget __P((pid_t, pfstype, struct mount *)); 57 58 LIST_HEAD(pfs_hashhead, pfsnode) *pfs_hashtbl; 59 u_long pfs_ihash; /* size of hash table - 1 */ 60 #define PFSPIDHASH(pid) (&pfs_hashtbl[(pid) & pfs_ihash]) 61 62 struct lock pfs_hashlock; 63 struct simplelock pfs_hash_slock; 64 65 #define ISSET(t, f) ((t) & (f)) 66 67 /* 68 * allocate a pfsnode/vnode pair. the vnode is 69 * referenced, and locked. 70 * 71 * the pid, pfs_type, and mount point uniquely 72 * identify a pfsnode. the mount point is needed 73 * because someone might mount this filesystem 74 * twice. 75 * 76 * all pfsnodes are maintained on a singly-linked 77 * list. new nodes are only allocated when they cannot 78 * be found on this list. entries on the list are 79 * removed when the vfs reclaim entry is called. 80 * 81 * a single lock is kept for the entire list. this is 82 * needed because the getnewvnode() function can block 83 * waiting for a vnode to become free, in which case there 84 * may be more than one process trying to get the same 85 * vnode. this lock is only taken if we are going to 86 * call getnewvnode, since the kernel itself is single-threaded. 87 * 88 * if an entry is found on the list, then call vget() to 89 * take a reference. this is done because there may be 90 * zero references to it and so it needs to removed from 91 * the vnode free list. 92 */ 93 int 94 procfs_allocvp(mp, vpp, pid, pfs_type) 95 struct mount *mp; 96 struct vnode **vpp; 97 long pid; 98 pfstype pfs_type; 99 { 100 struct pfsnode *pfs; 101 struct vnode *vp; 102 int error; 103 104 do { 105 if ((*vpp = procfs_hashget(pid, pfs_type, mp)) != NULL) 106 return (0); 107 } while (lockmgr(&pfs_hashlock, LK_EXCLUSIVE|LK_SLEEPFAIL, 0)); 108 109 if ((error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp)) != 0) { 110 *vpp = NULL; 111 lockmgr(&pfs_hashlock, LK_RELEASE, NULL); 112 return (error); 113 } 114 vp = *vpp; 115 116 MALLOC(pfs, void *, sizeof(struct pfsnode), M_TEMP, M_WAITOK); 117 vp->v_data = pfs; 118 119 pfs->pfs_pid = (pid_t) pid; 120 pfs->pfs_type = pfs_type; 121 pfs->pfs_vnode = vp; 122 pfs->pfs_flags = 0; 123 pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type); 124 125 switch (pfs_type) { 126 case Proot: /* /proc = dr-xr-xr-x */ 127 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 128 vp->v_type = VDIR; 129 vp->v_flag = VROOT; 130 break; 131 132 case Pcurproc: /* /proc/curproc = lr-xr-xr-x */ 133 case Pself: /* /proc/self = lr-xr-xr-x */ 134 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 135 vp->v_type = VLNK; 136 break; 137 138 case Pproc: /* /proc/N = dr-xr-xr-x */ 139 pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH; 140 vp->v_type = VDIR; 141 break; 142 143 case Pfile: /* /proc/N/file = -rw------- */ 144 case Pmem: /* /proc/N/mem = -rw------- */ 145 case Pregs: /* /proc/N/regs = -rw------- */ 146 case Pfpregs: /* /proc/N/fpregs = -rw------- */ 147 pfs->pfs_mode = S_IRUSR|S_IWUSR; 148 vp->v_type = VREG; 149 break; 150 151 case Pctl: /* /proc/N/ctl = --w------ */ 152 case Pnote: /* /proc/N/note = --w------ */ 153 case Pnotepg: /* /proc/N/notepg = --w------ */ 154 pfs->pfs_mode = S_IWUSR; 155 vp->v_type = VREG; 156 break; 157 158 case Pmap: /* /proc/N/map = -r--r--r-- */ 159 case Pmaps: /* /proc/N/maps = -r--r--r-- */ 160 case Pstatus: /* /proc/N/status = -r--r--r-- */ 161 case Pcmdline: /* /proc/N/cmdline = -r--r--r-- */ 162 case Pmeminfo: /* /proc/meminfo = -r--r--r-- */ 163 case Pcpuinfo: /* /proc/cpuinfo = -r--r--r-- */ 164 pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH; 165 vp->v_type = VREG; 166 break; 167 168 default: 169 panic("procfs_allocvp"); 170 } 171 172 procfs_hashins(pfs); 173 uvm_vnp_setsize(vp, 0); 174 lockmgr(&pfs_hashlock, LK_RELEASE, NULL); 175 176 return (error); 177 } 178 179 int 180 procfs_freevp(vp) 181 struct vnode *vp; 182 { 183 struct pfsnode *pfs = VTOPFS(vp); 184 185 procfs_hashrem(pfs); 186 187 FREE(vp->v_data, M_TEMP); 188 vp->v_data = 0; 189 return (0); 190 } 191 192 int 193 procfs_rw(v) 194 void *v; 195 { 196 struct vop_read_args *ap = v; 197 struct vnode *vp = ap->a_vp; 198 struct uio *uio = ap->a_uio; 199 struct proc *curp = uio->uio_procp; 200 struct pfsnode *pfs = VTOPFS(vp); 201 struct lwp *l; 202 struct proc *p; 203 204 p = PFIND(pfs->pfs_pid); 205 if (p == 0) 206 return (EINVAL); 207 208 /* XXX NJWLWP 209 * The entire procfs interface needs work to be useful to 210 * a process with multiple LWPs. For the moment, we'll 211 * just kluge this and fail on others. 212 */ 213 214 if (p->p_nlwps > 1) 215 switch (pfs->pfs_type) { 216 case Pnote: 217 case Pnotepg: 218 case Pstatus: 219 case Pmap: 220 case Pmem: 221 case Pcmdline: 222 break; 223 case Pregs: 224 case Pfpregs: 225 case Pctl: 226 default: 227 return (EOPNOTSUPP); 228 } 229 230 l = LIST_FIRST(&p->p_lwps); 231 232 switch (pfs->pfs_type) { 233 case Pregs: 234 case Pfpregs: 235 case Pmem: 236 /* 237 * Do not allow init to be modified while in secure mode; it 238 * could be duped into changing the security level. 239 */ 240 if (uio->uio_rw == UIO_WRITE && 241 p == initproc && securelevel > -1) 242 return (EPERM); 243 break; 244 245 default: 246 break; 247 } 248 249 switch (pfs->pfs_type) { 250 case Pnote: 251 case Pnotepg: 252 return (procfs_donote(curp, p, pfs, uio)); 253 254 case Pregs: 255 return (procfs_doregs(curp, l, pfs, uio)); 256 257 case Pfpregs: 258 return (procfs_dofpregs(curp, l, pfs, uio)); 259 260 case Pctl: 261 return (procfs_doctl(curp, l, pfs, uio)); 262 263 case Pstatus: 264 return (procfs_dostatus(curp, l, pfs, uio)); 265 266 case Pmap: 267 return (procfs_domap(curp, p, pfs, uio, 0)); 268 269 case Pmaps: 270 return (procfs_domap(curp, p, pfs, uio, 1)); 271 272 case Pmem: 273 return (procfs_domem(curp, l, pfs, uio)); 274 275 case Pcmdline: 276 return (procfs_docmdline(curp, p, pfs, uio)); 277 278 case Pmeminfo: 279 return (procfs_domeminfo(curp, p, pfs, uio)); 280 case Pcpuinfo: 281 return (procfs_docpuinfo(curp, p, pfs, uio)); 282 283 default: 284 return (EOPNOTSUPP); 285 } 286 } 287 288 /* 289 * Get a string from userland into (buf). Strip a trailing 290 * nl character (to allow easy access from the shell). 291 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr 292 * will automatically add a nul char at the end. 293 * 294 * Returns 0 on success or the following errors 295 * 296 * EINVAL: file offset is non-zero. 297 * EMSGSIZE: message is longer than kernel buffer 298 * EFAULT: user i/o buffer is not addressable 299 */ 300 int 301 vfs_getuserstr(uio, buf, buflenp) 302 struct uio *uio; 303 char *buf; 304 int *buflenp; 305 { 306 int xlen; 307 int error; 308 309 if (uio->uio_offset != 0) 310 return (EINVAL); 311 312 xlen = *buflenp; 313 314 /* must be able to read the whole string in one go */ 315 if (xlen < uio->uio_resid) 316 return (EMSGSIZE); 317 xlen = uio->uio_resid; 318 319 if ((error = uiomove(buf, xlen, uio)) != 0) 320 return (error); 321 322 /* allow multiple writes without seeks */ 323 uio->uio_offset = 0; 324 325 /* cleanup string and remove trailing newline */ 326 buf[xlen] = '\0'; 327 xlen = strlen(buf); 328 if (xlen > 0 && buf[xlen-1] == '\n') 329 buf[--xlen] = '\0'; 330 *buflenp = xlen; 331 332 return (0); 333 } 334 335 const vfs_namemap_t * 336 vfs_findname(nm, buf, buflen) 337 const vfs_namemap_t *nm; 338 const char *buf; 339 int buflen; 340 { 341 342 for (; nm->nm_name; nm++) 343 if (memcmp(buf, nm->nm_name, buflen+1) == 0) 344 return (nm); 345 346 return (0); 347 } 348 349 /* 350 * Initialize pfsnode hash table. 351 */ 352 void 353 procfs_hashinit() 354 { 355 lockinit(&pfs_hashlock, PINOD, "pfs_hashlock", 0, 0); 356 pfs_hashtbl = hashinit(desiredvnodes / 4, HASH_LIST, M_UFSMNT, 357 M_WAITOK, &pfs_ihash); 358 simple_lock_init(&pfs_hash_slock); 359 } 360 361 /* 362 * Free pfsnode hash table. 363 */ 364 void 365 procfs_hashdone() 366 { 367 hashdone(pfs_hashtbl, M_UFSMNT); 368 } 369 370 struct vnode * 371 procfs_hashget(pid, type, mp) 372 pid_t pid; 373 pfstype type; 374 struct mount *mp; 375 { 376 struct pfsnode *pp; 377 struct vnode *vp; 378 379 loop: 380 simple_lock(&pfs_hash_slock); 381 for (pp = PFSPIDHASH(pid)->lh_first; pp; pp = pp->pfs_hash.le_next) { 382 vp = PFSTOV(pp); 383 if (pid == pp->pfs_pid && pp->pfs_type == type && 384 vp->v_mount == mp) { 385 simple_lock(&vp->v_interlock); 386 simple_unlock(&pfs_hash_slock); 387 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK)) 388 goto loop; 389 return (vp); 390 } 391 } 392 simple_unlock(&pfs_hash_slock); 393 return (NULL); 394 } 395 396 /* 397 * Insert the pfsnode into the hash table and lock it. 398 */ 399 void 400 procfs_hashins(pp) 401 struct pfsnode *pp; 402 { 403 struct pfs_hashhead *ppp; 404 405 /* lock the pfsnode, then put it on the appropriate hash list */ 406 lockmgr(&pp->pfs_vnode->v_lock, LK_EXCLUSIVE, (struct simplelock *)0); 407 408 simple_lock(&pfs_hash_slock); 409 ppp = PFSPIDHASH(pp->pfs_pid); 410 LIST_INSERT_HEAD(ppp, pp, pfs_hash); 411 simple_unlock(&pfs_hash_slock); 412 } 413 414 /* 415 * Remove the pfsnode from the hash table. 416 */ 417 void 418 procfs_hashrem(pp) 419 struct pfsnode *pp; 420 { 421 simple_lock(&pfs_hash_slock); 422 LIST_REMOVE(pp, pfs_hash); 423 simple_unlock(&pfs_hash_slock); 424 } 425 426 void 427 procfs_revoke_vnodes(p, arg) 428 struct proc *p; 429 void *arg; 430 { 431 struct pfsnode *pfs, *pnext; 432 struct vnode *vp; 433 struct mount *mp = (struct mount *)arg; 434 435 if (!(p->p_flag & P_SUGID)) 436 return; 437 438 for (pfs = PFSPIDHASH(p->p_pid)->lh_first; pfs; pfs = pnext) { 439 vp = PFSTOV(pfs); 440 pnext = pfs->pfs_hash.le_next; 441 if (vp->v_usecount > 0 && pfs->pfs_pid == p->p_pid && 442 vp->v_mount == mp) 443 VOP_REVOKE(vp, REVOKEALL); 444 } 445 } 446
Indexes created Mon Sep 29 21:09:56 GMT 2025