1 /* 2 * Copyright (c) 1993 Jan-Simon Pendry 3 * Copyright (c) 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Jan-Simon Pendry. 8 * 9 * %sccs.include.redist.c% 10 * 11 * @(#)procfs_subr.c 8.5 (Berkeley) 06/15/94 12 * 13 * From: 14 * $Id: procfs_subr.c,v 3.2 1993/12/15 09:40:17 jsp Exp $ 15 */ 16 17 #include <sys/param.h> 18 #include <sys/systm.h> 19 #include <sys/time.h> 20 #include <sys/kernel.h> 21 #include <sys/proc.h> 22 #include <sys/vnode.h> 23 #include <sys/malloc.h> 24 #include <miscfs/procfs/procfs.h> 25 26 static struct pfsnode *pfshead; 27 static int pfsvplock; 28 29 /* 30 * allocate a pfsnode/vnode pair. the vnode is 31 * referenced, but not locked. 32 * 33 * the pid, pfs_type, and mount point uniquely 34 * identify a pfsnode. the mount point is needed 35 * because someone might mount this filesystem 36 * twice. 37 * 38 * all pfsnodes are maintained on a singly-linked 39 * list. new nodes are only allocated when they cannot 40 * be found on this list. entries on the list are 41 * removed when the vfs reclaim entry is called. 42 * 43 * a single lock is kept for the entire list. this is 44 * needed because the getnewvnode() function can block 45 * waiting for a vnode to become free, in which case there 46 * may be more than one process trying to get the same 47 * vnode. this lock is only taken if we are going to 48 * call getnewvnode, since the kernel itself is single-threaded. 49 * 50 * if an entry is found on the list, then call vget() to 51 * take a reference. this is done because there may be 52 * zero references to it and so it needs to removed from 53 * the vnode free list. 54 */ 55 int 56 procfs_allocvp(mp, vpp, pid, pfs_type) 57 struct mount *mp; 58 struct vnode **vpp; 59 long pid; 60 pfstype pfs_type; 61 { 62 struct pfsnode *pfs; 63 struct vnode *vp; 64 struct pfsnode **pp; 65 int error; 66 67 loop: 68 for (pfs = pfshead; pfs != 0; pfs = pfs->pfs_next) { 69 vp = PFSTOV(pfs); 70 if (pfs->pfs_pid == pid && 71 pfs->pfs_type == pfs_type && 72 vp->v_mount == mp) { 73 if (vget(vp, 0)) 74 goto loop; 75 *vpp = vp; 76 return (0); 77 } 78 } 79 80 /* 81 * otherwise lock the vp list while we call getnewvnode 82 * since that can block. 83 */ 84 if (pfsvplock & PROCFS_LOCKED) { 85 pfsvplock |= PROCFS_WANT; 86 sleep((caddr_t) &pfsvplock, PINOD); 87 goto loop; 88 } 89 pfsvplock |= PROCFS_LOCKED; 90 91 if (error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp)) 92 goto out; 93 vp = *vpp; 94 95 MALLOC(pfs, void *, sizeof(struct pfsnode), M_TEMP, M_WAITOK); 96 vp->v_data = pfs; 97 98 pfs->pfs_next = 0; 99 pfs->pfs_pid = (pid_t) pid; 100 pfs->pfs_type = pfs_type; 101 pfs->pfs_vnode = vp; 102 pfs->pfs_flags = 0; 103 pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type); 104 105 switch (pfs_type) { 106 case Proot: /* /proc = dr-xr-xr-x */ 107 pfs->pfs_mode = (VREAD|VEXEC) | 108 (VREAD|VEXEC) >> 3 | 109 (VREAD|VEXEC) >> 6; 110 vp->v_type = VDIR; 111 vp->v_flag = VROOT; 112 break; 113 114 case Pcurproc: /* /proc/curproc = lr--r--r-- */ 115 pfs->pfs_mode = (VREAD) | 116 (VREAD >> 3) | 117 (VREAD >> 6); 118 vp->v_type = VLNK; 119 break; 120 121 case Pproc: 122 pfs->pfs_mode = (VREAD|VEXEC) | 123 (VREAD|VEXEC) >> 3 | 124 (VREAD|VEXEC) >> 6; 125 vp->v_type = VDIR; 126 break; 127 128 case Pfile: 129 case Pmem: 130 case Pregs: 131 case Pfpregs: 132 pfs->pfs_mode = (VREAD|VWRITE); 133 vp->v_type = VREG; 134 break; 135 136 case Pctl: 137 case Pnote: 138 case Pnotepg: 139 pfs->pfs_mode = (VWRITE); 140 vp->v_type = VREG; 141 break; 142 143 case Pstatus: 144 pfs->pfs_mode = (VREAD) | 145 (VREAD >> 3) | 146 (VREAD >> 6); 147 vp->v_type = VREG; 148 break; 149 150 default: 151 panic("procfs_allocvp"); 152 } 153 154 /* add to procfs vnode list */ 155 for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next) 156 continue; 157 *pp = pfs; 158 159 out: 160 pfsvplock &= ~PROCFS_LOCKED; 161 162 if (pfsvplock & PROCFS_WANT) { 163 pfsvplock &= ~PROCFS_WANT; 164 wakeup((caddr_t) &pfsvplock); 165 } 166 167 return (error); 168 } 169 170 int 171 procfs_freevp(vp) 172 struct vnode *vp; 173 { 174 struct pfsnode **pfspp; 175 struct pfsnode *pfs = VTOPFS(vp); 176 177 for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) { 178 if (*pfspp == pfs) { 179 *pfspp = pfs->pfs_next; 180 break; 181 } 182 } 183 184 FREE(vp->v_data, M_TEMP); 185 vp->v_data = 0; 186 return (0); 187 } 188 189 int 190 procfs_rw(ap) 191 struct vop_read_args *ap; 192 { 193 struct vnode *vp = ap->a_vp; 194 struct uio *uio = ap->a_uio; 195 struct proc *curp = uio->uio_procp; 196 struct pfsnode *pfs = VTOPFS(vp); 197 struct proc *p; 198 199 p = PFIND(pfs->pfs_pid); 200 if (p == 0) 201 return (EINVAL); 202 203 switch (pfs->pfs_type) { 204 case Pnote: 205 case Pnotepg: 206 return (procfs_donote(curp, p, pfs, uio)); 207 208 case Pregs: 209 return (procfs_doregs(curp, p, pfs, uio)); 210 211 case Pfpregs: 212 return (procfs_dofpregs(curp, p, pfs, uio)); 213 214 case Pctl: 215 return (procfs_doctl(curp, p, pfs, uio)); 216 217 case Pstatus: 218 return (procfs_dostatus(curp, p, pfs, uio)); 219 220 case Pmem: 221 return (procfs_domem(curp, p, pfs, uio)); 222 223 default: 224 return (EOPNOTSUPP); 225 } 226 } 227 228 /* 229 * Get a string from userland into (buf). Strip a trailing 230 * nl character (to allow easy access from the shell). 231 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr 232 * will automatically add a nul char at the end. 233 * 234 * Returns 0 on success or the following errors 235 * 236 * EINVAL: file offset is non-zero. 237 * EMSGSIZE: message is longer than kernel buffer 238 * EFAULT: user i/o buffer is not addressable 239 */ 240 int 241 vfs_getuserstr(uio, buf, buflenp) 242 struct uio *uio; 243 char *buf; 244 int *buflenp; 245 { 246 int xlen; 247 int error; 248 249 if (uio->uio_offset != 0) 250 return (EINVAL); 251 252 xlen = *buflenp; 253 254 /* must be able to read the whole string in one go */ 255 if (xlen < uio->uio_resid) 256 return (EMSGSIZE); 257 xlen = uio->uio_resid; 258 259 if (error = uiomove(buf, xlen, uio)) 260 return (error); 261 262 /* allow multiple writes without seeks */ 263 uio->uio_offset = 0; 264 265 /* cleanup string and remove trailing newline */ 266 buf[xlen] = '\0'; 267 xlen = strlen(buf); 268 if (xlen > 0 && buf[xlen-1] == '\n') 269 buf[--xlen] = '\0'; 270 *buflenp = xlen; 271 272 return (0); 273 } 274 275 vfs_namemap_t * 276 vfs_findname(nm, buf, buflen) 277 vfs_namemap_t *nm; 278 char *buf; 279 int buflen; 280 { 281 282 for (; nm->nm_name; nm++) 283 if (bcmp(buf, (char *) nm->nm_name, buflen+1) == 0) 284 return (nm); 285 286 return (0); 287 } 288