procfs_subr.c revision 1.31.4.1
1 /* $NetBSD: procfs_subr.c,v 1.31.4.1 2001/03/30 21:49:23 he 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, 0); 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 Pstatus: /* /proc/N/status = -r--r--r-- */ 160 case Pcmdline: /* /proc/N/cmdline = -r--r--r-- */ 161 case Pmeminfo: /* /proc/meminfo = -r--r--r-- */ 162 case Pcpuinfo: /* /proc/cpuinfo = -r--r--r-- */ 163 pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH; 164 vp->v_type = VREG; 165 break; 166 167 default: 168 panic("procfs_allocvp"); 169 } 170 171 procfs_hashins(pfs); 172 lockmgr(&pfs_hashlock, LK_RELEASE, 0); 173 174 return (error); 175 } 176 177 int 178 procfs_freevp(vp) 179 struct vnode *vp; 180 { 181 struct pfsnode *pfs = VTOPFS(vp); 182 183 procfs_hashrem(pfs); 184 185 FREE(vp->v_data, M_TEMP); 186 vp->v_data = 0; 187 return (0); 188 } 189 190 int 191 procfs_rw(v) 192 void *v; 193 { 194 struct vop_read_args *ap = v; 195 struct vnode *vp = ap->a_vp; 196 struct uio *uio = ap->a_uio; 197 struct proc *curp = uio->uio_procp; 198 struct pfsnode *pfs = VTOPFS(vp); 199 struct proc *p; 200 201 p = PFIND(pfs->pfs_pid); 202 if (p == 0) 203 return (EINVAL); 204 205 switch (pfs->pfs_type) { 206 case Pregs: 207 case Pfpregs: 208 case Pmem: 209 /* 210 * Do not allow init to be modified while in secure mode; it 211 * could be duped into changing the security level. 212 */ 213 if (uio->uio_rw == UIO_WRITE && 214 p == initproc && securelevel > -1) 215 return (EPERM); 216 break; 217 218 default: 219 break; 220 } 221 222 switch (pfs->pfs_type) { 223 case Pnote: 224 case Pnotepg: 225 return (procfs_donote(curp, p, pfs, uio)); 226 227 case Pregs: 228 return (procfs_doregs(curp, p, pfs, uio)); 229 230 case Pfpregs: 231 return (procfs_dofpregs(curp, p, pfs, uio)); 232 233 case Pctl: 234 return (procfs_doctl(curp, p, pfs, uio)); 235 236 case Pstatus: 237 return (procfs_dostatus(curp, p, pfs, uio)); 238 239 case Pmap: 240 return (procfs_domap(curp, p, pfs, uio)); 241 242 case Pmem: 243 return (procfs_domem(curp, p, pfs, uio)); 244 245 case Pcmdline: 246 return (procfs_docmdline(curp, p, pfs, uio)); 247 248 case Pmeminfo: 249 return (procfs_domeminfo(curp, p, pfs, uio)); 250 case Pcpuinfo: 251 return (procfs_docpuinfo(curp, p, pfs, uio)); 252 253 default: 254 return (EOPNOTSUPP); 255 } 256 } 257 258 /* 259 * Get a string from userland into (buf). Strip a trailing 260 * nl character (to allow easy access from the shell). 261 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr 262 * will automatically add a nul char at the end. 263 * 264 * Returns 0 on success or the following errors 265 * 266 * EINVAL: file offset is non-zero. 267 * EMSGSIZE: message is longer than kernel buffer 268 * EFAULT: user i/o buffer is not addressable 269 */ 270 int 271 vfs_getuserstr(uio, buf, buflenp) 272 struct uio *uio; 273 char *buf; 274 int *buflenp; 275 { 276 int xlen; 277 int error; 278 279 if (uio->uio_offset != 0) 280 return (EINVAL); 281 282 xlen = *buflenp; 283 284 /* must be able to read the whole string in one go */ 285 if (xlen < uio->uio_resid) 286 return (EMSGSIZE); 287 xlen = uio->uio_resid; 288 289 if ((error = uiomove(buf, xlen, uio)) != 0) 290 return (error); 291 292 /* allow multiple writes without seeks */ 293 uio->uio_offset = 0; 294 295 /* cleanup string and remove trailing newline */ 296 buf[xlen] = '\0'; 297 xlen = strlen(buf); 298 if (xlen > 0 && buf[xlen-1] == '\n') 299 buf[--xlen] = '\0'; 300 *buflenp = xlen; 301 302 return (0); 303 } 304 305 vfs_namemap_t * 306 vfs_findname(nm, buf, buflen) 307 vfs_namemap_t *nm; 308 char *buf; 309 int buflen; 310 { 311 312 for (; nm->nm_name; nm++) 313 if (memcmp(buf, nm->nm_name, buflen+1) == 0) 314 return (nm); 315 316 return (0); 317 } 318 319 /* 320 * Initialize pfsnode hash table. 321 */ 322 void 323 procfs_hashinit() 324 { 325 lockinit(&pfs_hashlock, PINOD, "pfs_hashlock", 0, 0); 326 pfs_hashtbl = hashinit(desiredvnodes / 4, M_UFSMNT, M_WAITOK, 327 &pfs_ihash); 328 simple_lock_init(&pfs_hash_slock); 329 } 330 331 /* 332 * Free pfsnode hash table. 333 */ 334 void 335 procfs_hashdone() 336 { 337 hashdone(pfs_hashtbl, M_UFSMNT); 338 } 339 340 struct vnode * 341 procfs_hashget(pid, type, mp) 342 pid_t pid; 343 pfstype type; 344 struct mount *mp; 345 { 346 struct pfsnode *pp; 347 struct vnode *vp; 348 349 loop: 350 simple_lock(&pfs_hash_slock); 351 for (pp = PFSPIDHASH(pid)->lh_first; pp; pp = pp->pfs_hash.le_next) { 352 vp = PFSTOV(pp); 353 if (pid == pp->pfs_pid && pp->pfs_type == type && 354 vp->v_mount == mp) { 355 simple_lock(&vp->v_interlock); 356 simple_unlock(&pfs_hash_slock); 357 if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK)) 358 goto loop; 359 return (vp); 360 } 361 } 362 simple_unlock(&pfs_hash_slock); 363 return (NULL); 364 } 365 366 /* 367 * Insert the pfsnode into the hash table and lock it. 368 */ 369 void 370 procfs_hashins(pp) 371 struct pfsnode *pp; 372 { 373 struct pfs_hashhead *ppp; 374 375 /* lock the pfsnode, then put it on the appropriate hash list */ 376 lockmgr(&pp->pfs_vnode->v_lock, LK_EXCLUSIVE, (struct simplelock *)0); 377 378 simple_lock(&pfs_hash_slock); 379 ppp = PFSPIDHASH(pp->pfs_pid); 380 LIST_INSERT_HEAD(ppp, pp, pfs_hash); 381 simple_unlock(&pfs_hash_slock); 382 } 383 384 /* 385 * Remove the pfsnode from the hash table. 386 */ 387 void 388 procfs_hashrem(pp) 389 struct pfsnode *pp; 390 { 391 simple_lock(&pfs_hash_slock); 392 LIST_REMOVE(pp, pfs_hash); 393 simple_unlock(&pfs_hash_slock); 394 } 395 396 void 397 procfs_revoke_vnodes(p, arg) 398 struct proc *p; 399 void *arg; 400 { 401 struct pfsnode *pfs, *pnext; 402 struct vnode *vp; 403 struct mount *mp = (struct mount *)arg; 404 405 if (!(p->p_flag & P_SUGID)) 406 return; 407 408 for (pfs = PFSPIDHASH(p->p_pid)->lh_first; pfs; pfs = pnext) { 409 vp = PFSTOV(pfs); 410 pnext = pfs->pfs_hash.le_next; 411 if (vp->v_usecount > 0 && pfs->pfs_pid == p->p_pid && 412 vp->v_mount == mp) 413 VOP_REVOKE(vp, REVOKEALL); 414 } 415 } 416
Indexes created Sat Sep 27 22:09:54 GMT 2025