1 /* $NetBSD: procfs_subr.c,v 1.13 1994/06/29 06:34:57 cgd Exp $ */ 2 3 /* 4 * Copyright (c) 1993 Jan-Simon Pendry 5 * Copyright (c) 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Jan-Simon Pendry. 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 University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * @(#)procfs_subr.c 8.5 (Berkeley) 6/15/94 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/time.h> 45 #include <sys/kernel.h> 46 #include <sys/proc.h> 47 #include <sys/vnode.h> 48 #include <sys/malloc.h> 49 #include <miscfs/procfs/procfs.h> 50 51 static struct pfsnode *pfshead; 52 static int pfsvplock; 53 54 /* 55 * allocate a pfsnode/vnode pair. the vnode is 56 * referenced, but not locked. 57 * 58 * the pid, pfs_type, and mount point uniquely 59 * identify a pfsnode. the mount point is needed 60 * because someone might mount this filesystem 61 * twice. 62 * 63 * all pfsnodes are maintained on a singly-linked 64 * list. new nodes are only allocated when they cannot 65 * be found on this list. entries on the list are 66 * removed when the vfs reclaim entry is called. 67 * 68 * a single lock is kept for the entire list. this is 69 * needed because the getnewvnode() function can block 70 * waiting for a vnode to become free, in which case there 71 * may be more than one process trying to get the same 72 * vnode. this lock is only taken if we are going to 73 * call getnewvnode, since the kernel itself is single-threaded. 74 * 75 * if an entry is found on the list, then call vget() to 76 * take a reference. this is done because there may be 77 * zero references to it and so it needs to removed from 78 * the vnode free list. 79 */ 80 int 81 procfs_allocvp(mp, vpp, pid, pfs_type) 82 struct mount *mp; 83 struct vnode **vpp; 84 long pid; 85 pfstype pfs_type; 86 { 87 struct pfsnode *pfs; 88 struct vnode *vp; 89 struct pfsnode **pp; 90 int error; 91 92 loop: 93 for (pfs = pfshead; pfs != 0; pfs = pfs->pfs_next) { 94 vp = PFSTOV(pfs); 95 if (pfs->pfs_pid == pid && 96 pfs->pfs_type == pfs_type && 97 vp->v_mount == mp) { 98 if (vget(vp, 0)) 99 goto loop; 100 *vpp = vp; 101 return (0); 102 } 103 } 104 105 /* 106 * otherwise lock the vp list while we call getnewvnode 107 * since that can block. 108 */ 109 if (pfsvplock & PROCFS_LOCKED) { 110 pfsvplock |= PROCFS_WANT; 111 sleep((caddr_t) &pfsvplock, PINOD); 112 goto loop; 113 } 114 pfsvplock |= PROCFS_LOCKED; 115 116 if (error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp)) 117 goto out; 118 vp = *vpp; 119 120 MALLOC(pfs, void *, sizeof(struct pfsnode), M_TEMP, M_WAITOK); 121 vp->v_data = pfs; 122 123 pfs->pfs_next = 0; 124 pfs->pfs_pid = (pid_t) pid; 125 pfs->pfs_type = pfs_type; 126 pfs->pfs_vnode = vp; 127 pfs->pfs_flags = 0; 128 pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type); 129 130 switch (pfs_type) { 131 case Proot: /* /proc = dr-xr-xr-x */ 132 pfs->pfs_mode = (VREAD|VEXEC) | 133 (VREAD|VEXEC) >> 3 | 134 (VREAD|VEXEC) >> 6; 135 vp->v_type = VDIR; 136 vp->v_flag = VROOT; 137 break; 138 139 case Pcurproc: /* /proc/curproc = lr--r--r-- */ 140 pfs->pfs_mode = (VREAD) | 141 (VREAD >> 3) | 142 (VREAD >> 6); 143 vp->v_type = VLNK; 144 break; 145 146 case Pproc: 147 pfs->pfs_mode = (VREAD|VEXEC) | 148 (VREAD|VEXEC) >> 3 | 149 (VREAD|VEXEC) >> 6; 150 vp->v_type = VDIR; 151 break; 152 153 case Pfile: 154 case Pmem: 155 case Pregs: 156 case Pfpregs: 157 pfs->pfs_mode = (VREAD|VWRITE); 158 vp->v_type = VREG; 159 break; 160 161 case Pctl: 162 case Pnote: 163 case Pnotepg: 164 pfs->pfs_mode = (VWRITE); 165 vp->v_type = VREG; 166 break; 167 168 case Pstatus: 169 pfs->pfs_mode = (VREAD) | 170 (VREAD >> 3) | 171 (VREAD >> 6); 172 vp->v_type = VREG; 173 break; 174 175 default: 176 panic("procfs_allocvp"); 177 } 178 179 /* add to procfs vnode list */ 180 for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next) 181 continue; 182 *pp = pfs; 183 184 out: 185 pfsvplock &= ~PROCFS_LOCKED; 186 187 if (pfsvplock & PROCFS_WANT) { 188 pfsvplock &= ~PROCFS_WANT; 189 wakeup((caddr_t) &pfsvplock); 190 } 191 192 return (error); 193 } 194 195 int 196 procfs_freevp(vp) 197 struct vnode *vp; 198 { 199 struct pfsnode **pfspp; 200 struct pfsnode *pfs = VTOPFS(vp); 201 202 for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) { 203 if (*pfspp == pfs) { 204 *pfspp = pfs->pfs_next; 205 break; 206 } 207 } 208 209 FREE(vp->v_data, M_TEMP); 210 vp->v_data = 0; 211 return (0); 212 } 213 214 int 215 procfs_rw(ap) 216 struct vop_read_args *ap; 217 { 218 struct vnode *vp = ap->a_vp; 219 struct uio *uio = ap->a_uio; 220 struct proc *curp = uio->uio_procp; 221 struct pfsnode *pfs = VTOPFS(vp); 222 struct proc *p; 223 224 p = PFIND(pfs->pfs_pid); 225 if (p == 0) 226 return (EINVAL); 227 228 switch (pfs->pfs_type) { 229 case Pnote: 230 case Pnotepg: 231 return (procfs_donote(curp, p, pfs, uio)); 232 233 case Pregs: 234 return (procfs_doregs(curp, p, pfs, uio)); 235 236 case Pfpregs: 237 return (procfs_dofpregs(curp, p, pfs, uio)); 238 239 case Pctl: 240 return (procfs_doctl(curp, p, pfs, uio)); 241 242 case Pstatus: 243 return (procfs_dostatus(curp, p, pfs, uio)); 244 245 case Pmem: 246 return (procfs_domem(curp, p, pfs, uio)); 247 248 default: 249 return (EOPNOTSUPP); 250 } 251 } 252 253 /* 254 * Get a string from userland into (buf). Strip a trailing 255 * nl character (to allow easy access from the shell). 256 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr 257 * will automatically add a nul char at the end. 258 * 259 * Returns 0 on success or the following errors 260 * 261 * EINVAL: file offset is non-zero. 262 * EMSGSIZE: message is longer than kernel buffer 263 * EFAULT: user i/o buffer is not addressable 264 */ 265 int 266 vfs_getuserstr(uio, buf, buflenp) 267 struct uio *uio; 268 char *buf; 269 int *buflenp; 270 { 271 int xlen; 272 int error; 273 274 if (uio->uio_offset != 0) 275 return (EINVAL); 276 277 xlen = *buflenp; 278 279 /* must be able to read the whole string in one go */ 280 if (xlen < uio->uio_resid) 281 return (EMSGSIZE); 282 xlen = uio->uio_resid; 283 284 if (error = uiomove(buf, xlen, uio)) 285 return (error); 286 287 /* allow multiple writes without seeks */ 288 uio->uio_offset = 0; 289 290 /* cleanup string and remove trailing newline */ 291 buf[xlen] = '\0'; 292 xlen = strlen(buf); 293 if (xlen > 0 && buf[xlen-1] == '\n') 294 buf[--xlen] = '\0'; 295 *buflenp = xlen; 296 297 return (0); 298 } 299 300 vfs_namemap_t * 301 vfs_findname(nm, buf, buflen) 302 vfs_namemap_t *nm; 303 char *buf; 304 int buflen; 305 { 306 307 for (; nm->nm_name; nm++) 308 if (bcmp(buf, (char *) nm->nm_name, buflen+1) == 0) 309 return (nm); 310 311 return (0); 312 } 313