1 /* 2 * Copyright (c) 1993 The Regents of the University of California. 3 * Copyright (c) 1993 Jan-Simon Pendry 4 * 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 8.1 (Berkeley) 01/05/94 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 int error; 63 struct pfsnode *pfs; 64 struct pfsnode **pp; 65 66 loop: 67 for (pfs = pfshead; pfs != 0; pfs = pfs->pfs_next) { 68 if (pfs->pfs_pid == pid && 69 pfs->pfs_type == pfs_type && 70 PFSTOV(pfs)->v_mount == mp) { 71 if (vget(pfs->pfs_vnode, 1)) 72 goto loop; 73 VOP_UNLOCK(pfs->pfs_vnode); 74 *vpp = pfs->pfs_vnode; 75 return (0); 76 } 77 } 78 79 /* 80 * otherwise lock the vp list while we call getnewvnode 81 * since that can block. 82 */ 83 if (pfsvplock & PROCFS_LOCKED) { 84 pfsvplock |= PROCFS_WANT; 85 sleep((caddr_t) &pfsvplock, PINOD); 86 goto loop; 87 } 88 pfsvplock |= PROCFS_LOCKED; 89 90 error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp); 91 if (error) 92 goto out; 93 94 MALLOC((*vpp)->v_data, void *, sizeof(struct pfsnode), 95 M_TEMP, M_WAITOK); 96 97 pfs = VTOPFS(*vpp); 98 pfs->pfs_next = 0; 99 pfs->pfs_pid = (pid_t) pid; 100 pfs->pfs_type = pfs_type; 101 pfs->pfs_vnode = *vpp; 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 break; 111 112 case Pproc: 113 pfs->pfs_mode = (VREAD|VEXEC) | 114 (VREAD|VEXEC) >> 3 | 115 (VREAD|VEXEC) >> 6; 116 break; 117 118 case Pfile: 119 pfs->pfs_mode = (VREAD|VWRITE); 120 break; 121 122 case Pmem: 123 pfs->pfs_mode = (VREAD|VWRITE); 124 break; 125 126 case Pregs: 127 pfs->pfs_mode = (VREAD|VWRITE); 128 break; 129 130 case Pctl: 131 pfs->pfs_mode = (VWRITE); 132 break; 133 134 case Pstatus: 135 pfs->pfs_mode = (VREAD) | 136 (VREAD >> 3) | 137 (VREAD >> 6); 138 break; 139 140 case Pnote: 141 pfs->pfs_mode = (VWRITE); 142 break; 143 144 case Pnotepg: 145 pfs->pfs_mode = (VWRITE); 146 break; 147 148 default: 149 panic("procfs_allocvp"); 150 } 151 152 /* add to procfs vnode list */ 153 for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next) 154 continue; 155 *pp = pfs; 156 157 out: 158 pfsvplock &= ~PROCFS_LOCKED; 159 160 if (pfsvplock & PROCFS_WANT) { 161 pfsvplock &= ~PROCFS_WANT; 162 wakeup((caddr_t) &pfsvplock); 163 } 164 165 return (error); 166 } 167 168 int 169 procfs_freevp(vp) 170 struct vnode *vp; 171 { 172 struct pfsnode **pfspp; 173 struct pfsnode *pfs = VTOPFS(vp); 174 175 for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) { 176 if (*pfspp == pfs) { 177 *pfspp = pfs->pfs_next; 178 break; 179 } 180 } 181 182 FREE(vp->v_data, M_TEMP); 183 vp->v_data = 0; 184 return (0); 185 } 186 187 int 188 procfs_rw(ap) 189 struct vop_read_args *ap; 190 { 191 struct vnode *vp = ap->a_vp; 192 struct uio *uio = ap->a_uio; 193 struct proc *curp = uio->uio_procp; 194 struct pfsnode *pfs = VTOPFS(vp); 195 struct proc *p; 196 197 p = PFIND(pfs->pfs_pid); 198 if (p == 0) 199 return (EINVAL); 200 201 switch (pfs->pfs_type) { 202 case Pnote: 203 case Pnotepg: 204 return (procfs_donote(curp, p, pfs, uio)); 205 206 case Pregs: 207 return (procfs_doregs(curp, p, pfs, uio)); 208 209 case Pctl: 210 return (procfs_doctl(curp, p, pfs, uio)); 211 212 case Pstatus: 213 return (procfs_dostatus(curp, p, pfs, uio)); 214 215 case Pmem: 216 return (procfs_domem(curp, p, pfs, uio)); 217 218 default: 219 return (EOPNOTSUPP); 220 } 221 } 222 223 /* 224 * Get a string from userland into (buf). Strip a trailing 225 * nl character (to allow easy access from the shell). 226 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr 227 * will automatically add a nul char at the end. 228 * 229 * Returns 0 on success or the following errors 230 * 231 * EINVAL: file offset is non-zero. 232 * EMSGSIZE: message is longer than kernel buffer 233 * EFAULT: user i/o buffer is not addressable 234 */ 235 int 236 vfs_getuserstr(uio, buf, buflenp) 237 struct uio *uio; 238 char *buf; 239 int *buflenp; 240 { 241 int xlen; 242 int error; 243 244 if (uio->uio_offset != 0) 245 return (EINVAL); 246 247 xlen = *buflenp; 248 249 /* must be able to read the whole string in one go */ 250 if (xlen < uio->uio_resid) 251 return (EMSGSIZE); 252 xlen = uio->uio_resid; 253 254 error = uiomove(buf, xlen, uio); 255 if (error) 256 return (error); 257 258 /* allow multiple writes without seeks */ 259 uio->uio_offset = 0; 260 261 /* cleanup string and remove trailing newline */ 262 buf[xlen] = '\0'; 263 xlen = strlen(buf); 264 if (xlen > 0 && buf[xlen-1] == '\n') 265 buf[--xlen] = '\0'; 266 *buflenp = xlen; 267 268 return (0); 269 } 270 271 vfs_namemap_t * 272 vfs_findname(nm, buf, buflen) 273 vfs_namemap_t *nm; 274 char *buf; 275 int buflen; 276 { 277 for (; nm->nm_name; nm++) 278 if (bcmp(buf, (char *) nm->nm_name, buflen+1) == 0) 279 return (nm); 280 281 return (0); 282 } 283