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 8.3 (Berkeley) 01/21/94 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, 0)) 72 goto loop; 73 *vpp = pfs->pfs_vnode; 74 return (0); 75 } 76 } 77 78 /* 79 * otherwise lock the vp list while we call getnewvnode 80 * since that can block. 81 */ 82 if (pfsvplock & PROCFS_LOCKED) { 83 pfsvplock |= PROCFS_WANT; 84 sleep((caddr_t) &pfsvplock, PINOD); 85 goto loop; 86 } 87 pfsvplock |= PROCFS_LOCKED; 88 89 error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp); 90 if (error) 91 goto out; 92 93 MALLOC((*vpp)->v_data, void *, sizeof(struct pfsnode), 94 M_TEMP, M_WAITOK); 95 96 pfs = VTOPFS(*vpp); 97 pfs->pfs_next = 0; 98 pfs->pfs_pid = (pid_t) pid; 99 pfs->pfs_type = pfs_type; 100 pfs->pfs_vnode = *vpp; 101 pfs->pfs_flags = 0; 102 pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type); 103 104 switch (pfs_type) { 105 case Proot: /* /proc = dr-xr-xr-x */ 106 pfs->pfs_mode = (VREAD|VEXEC) | 107 (VREAD|VEXEC) >> 3 | 108 (VREAD|VEXEC) >> 6; 109 break; 110 111 case Pproc: 112 pfs->pfs_mode = (VREAD|VEXEC) | 113 (VREAD|VEXEC) >> 3 | 114 (VREAD|VEXEC) >> 6; 115 break; 116 117 case Pfile: 118 pfs->pfs_mode = (VREAD|VWRITE); 119 break; 120 121 case Pmem: 122 pfs->pfs_mode = (VREAD|VWRITE); 123 break; 124 125 case Pregs: 126 pfs->pfs_mode = (VREAD|VWRITE); 127 break; 128 129 case Pctl: 130 pfs->pfs_mode = (VWRITE); 131 break; 132 133 case Pstatus: 134 pfs->pfs_mode = (VREAD) | 135 (VREAD >> 3) | 136 (VREAD >> 6); 137 break; 138 139 case Pnote: 140 pfs->pfs_mode = (VWRITE); 141 break; 142 143 case Pnotepg: 144 pfs->pfs_mode = (VWRITE); 145 break; 146 147 default: 148 panic("procfs_allocvp"); 149 } 150 151 /* add to procfs vnode list */ 152 for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next) 153 continue; 154 *pp = pfs; 155 156 out: 157 pfsvplock &= ~PROCFS_LOCKED; 158 159 if (pfsvplock & PROCFS_WANT) { 160 pfsvplock &= ~PROCFS_WANT; 161 wakeup((caddr_t) &pfsvplock); 162 } 163 164 return (error); 165 } 166 167 int 168 procfs_freevp(vp) 169 struct vnode *vp; 170 { 171 struct pfsnode **pfspp; 172 struct pfsnode *pfs = VTOPFS(vp); 173 174 for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) { 175 if (*pfspp == pfs) { 176 *pfspp = pfs->pfs_next; 177 break; 178 } 179 } 180 181 FREE(vp->v_data, M_TEMP); 182 vp->v_data = 0; 183 return (0); 184 } 185 186 int 187 procfs_rw(ap) 188 struct vop_read_args *ap; 189 { 190 struct vnode *vp = ap->a_vp; 191 struct uio *uio = ap->a_uio; 192 struct proc *curp = uio->uio_procp; 193 struct pfsnode *pfs = VTOPFS(vp); 194 struct proc *p; 195 196 p = PFIND(pfs->pfs_pid); 197 if (p == 0) 198 return (EINVAL); 199 200 switch (pfs->pfs_type) { 201 case Pnote: 202 case Pnotepg: 203 return (procfs_donote(curp, p, pfs, uio)); 204 205 case Pregs: 206 return (procfs_doregs(curp, p, pfs, uio)); 207 208 case Pctl: 209 return (procfs_doctl(curp, p, pfs, uio)); 210 211 case Pstatus: 212 return (procfs_dostatus(curp, p, pfs, uio)); 213 214 case Pmem: 215 return (procfs_domem(curp, p, pfs, uio)); 216 217 default: 218 return (EOPNOTSUPP); 219 } 220 } 221 222 /* 223 * Get a string from userland into (buf). Strip a trailing 224 * nl character (to allow easy access from the shell). 225 * The buffer should be *buflenp + 1 chars long. vfs_getuserstr 226 * will automatically add a nul char at the end. 227 * 228 * Returns 0 on success or the following errors 229 * 230 * EINVAL: file offset is non-zero. 231 * EMSGSIZE: message is longer than kernel buffer 232 * EFAULT: user i/o buffer is not addressable 233 */ 234 int 235 vfs_getuserstr(uio, buf, buflenp) 236 struct uio *uio; 237 char *buf; 238 int *buflenp; 239 { 240 int xlen; 241 int error; 242 243 if (uio->uio_offset != 0) 244 return (EINVAL); 245 246 xlen = *buflenp; 247 248 /* must be able to read the whole string in one go */ 249 if (xlen < uio->uio_resid) 250 return (EMSGSIZE); 251 xlen = uio->uio_resid; 252 253 error = uiomove(buf, xlen, uio); 254 if (error) 255 return (error); 256 257 /* allow multiple writes without seeks */ 258 uio->uio_offset = 0; 259 260 /* cleanup string and remove trailing newline */ 261 buf[xlen] = '\0'; 262 xlen = strlen(buf); 263 if (xlen > 0 && buf[xlen-1] == '\n') 264 buf[--xlen] = '\0'; 265 *buflenp = xlen; 266 267 return (0); 268 } 269 270 vfs_namemap_t * 271 vfs_findname(nm, buf, buflen) 272 vfs_namemap_t *nm; 273 char *buf; 274 int buflen; 275 { 276 for (; nm->nm_name; nm++) 277 if (bcmp(buf, (char *) nm->nm_name, buflen+1) == 0) 278 return (nm); 279 280 return (0); 281 } 282