sys/fs/procfs/procfs_map.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   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. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  *      @(#)procfs_status.c     8.3 (Berkeley) 2/17/94
  36  */
  37
  38 #include <sys/param.h>
  39 #include <sys/systm.h>
  40 #include <sys/lock.h>
  41 #include <sys/filedesc.h>
  42 #include <sys/malloc.h>
  43 #include <sys/mount.h>
  44 #include <sys/proc.h>
  45 #include <sys/resourcevar.h>
  46 #include <sys/rwlock.h>
  47 #include <sys/sbuf.h>
  48 #ifdef COMPAT_FREEBSD32
  49 #include <sys/sysent.h>
  50 #endif
  51 #include <sys/uio.h>
  52 #include <sys/user.h>
  53 #include <sys/vnode.h>
  54
  55 #include <fs/pseudofs/pseudofs.h>
  56 #include <fs/procfs/procfs.h>
  57
  58 #include <vm/vm.h>
  59 #include <vm/vm_extern.h>
  60 #include <vm/pmap.h>
  61 #include <vm/vm_map.h>
  62 #include <vm/vm_page.h>
  63 #include <vm/vm_object.h>
  64
  65 #define MEBUFFERSIZE 256
  66
  67 /*
  68  * The map entries can *almost* be read with programs like cat.  However,
  69  * large maps need special programs to read.  It is not easy to implement
  70  * a program that can sense the required size of the buffer, and then
  71  * subsequently do a read with the appropriate size.  This operation cannot
  72  * be atomic.  The best that we can do is to allow the program to do a read
  73  * with an arbitrarily large buffer, and return as much as we can.  We can
  74  * return an error code if the buffer is too small (EFBIG), then the program
  75  * can try a bigger buffer.
  76  */
  77 int
  78 procfs_doprocmap(PFS_FILL_ARGS)
  79 {
  80         struct vmspace *vm;
  81         vm_map_t map;
  82         vm_map_entry_t entry, tmp_entry;
  83         struct vnode *vp;
  84         char *fullpath, *freepath, *type;
  85         struct ucred *cred;
  86         vm_object_t lobj, nobj, obj, tobj;
  87         int error, flags, kvme, privateresident, ref_count, resident;
  88         int shadow_count;
  89         vm_offset_t e_start, e_end;
  90         vm_eflags_t e_eflags;
  91         vm_prot_t e_prot;
  92         unsigned int last_timestamp;
  93         bool super;
  94 #ifdef COMPAT_FREEBSD32
  95         bool wrap32;
  96 #endif
  97
  98         PROC_LOCK(p);
  99         error = p_candebug(td, p);
 100         PROC_UNLOCK(p);
 101         if (error)
 102                 return (error);
 103
 104         if (uio->uio_rw != UIO_READ)
 105                 return (EOPNOTSUPP);
 106
 107 #ifdef COMPAT_FREEBSD32
 108         wrap32 = false;
 109         if (SV_CURPROC_FLAG(SV_ILP32)) {
 110                 if (!(SV_PROC_FLAG(p, SV_ILP32)))
 111                         return (EOPNOTSUPP);
 112                 wrap32 = true;
 113         }
 114 #endif
 115
 116         vm = vmspace_acquire_ref(p);
 117         if (vm == NULL)
 118                 return (ESRCH);
 119         map = &vm->vm_map;
 120         vm_map_lock_read(map);
 121         VM_MAP_ENTRY_FOREACH(entry, map) {
 122                 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
 123                         continue;
 124
 125                 e_eflags = entry->eflags;
 126                 e_prot = entry->protection;
 127                 e_start = entry->start;
 128                 e_end = entry->end;
 129                 privateresident = 0;
 130                 resident = 0;
 131                 obj = entry->object.vm_object;
 132                 if (obj != NULL) {
 133                         VM_OBJECT_RLOCK(obj);
 134                         if (obj->shadow_count == 1)
 135                                 privateresident = obj->resident_page_count;
 136                 }
 137                 cred = (entry->cred) ? entry->cred : (obj ? obj->cred : NULL);
 138
 139                 for (lobj = tobj = obj; tobj != NULL;
 140                     tobj = tobj->backing_object) {
 141                         if (tobj != obj)
 142                                 VM_OBJECT_RLOCK(tobj);
 143                         lobj = tobj;
 144                 }
 145                 if (obj != NULL)
 146                         kern_proc_vmmap_resident(map, entry, &resident, &super);
 147                 for (tobj = obj; tobj != NULL; tobj = nobj) {
 148                         nobj = tobj->backing_object;
 149                         if (tobj != obj && tobj != lobj)
 150                                 VM_OBJECT_RUNLOCK(tobj);
 151                 }
 152                 last_timestamp = map->timestamp;
 153                 vm_map_unlock_read(map);
 154
 155                 freepath = NULL;
 156                 fullpath = "-";
 157                 if (lobj) {
 158                         kvme = vm_object_kvme_type(lobj, &vp);
 159                         if (vp != NULL)
 160                                 vref(vp);
 161                         switch (kvme) {
 162                         default:
 163                                 type = "unknown";
 164                                 break;
 165                         case KVME_TYPE_PHYS:
 166                                 type = "phys";
 167                                 break;
 168                         case KVME_TYPE_SWAP:
 169                                 type = "swap";
 170                                 break;
 171                         case KVME_TYPE_DEAD:
 172                                 type = "dead";
 173                                 break;
 174                         case KVME_TYPE_VNODE:
 175                                 type = "vnode";
 176                                 break;
 177                         case KVME_TYPE_SG:
 178                         case KVME_TYPE_DEVICE:
 179                         case KVME_TYPE_MGTDEVICE:
 180                                 type = "device";
 181                                 break;
 182                         }
 183                         if (lobj != obj)
 184                                 VM_OBJECT_RUNLOCK(lobj);
 185
 186                         flags = obj->flags;
 187                         ref_count = obj->ref_count;
 188                         shadow_count = obj->shadow_count;
 189                         VM_OBJECT_RUNLOCK(obj);
 190                         if (vp != NULL) {
 191                                 vn_fullpath(vp, &fullpath, &freepath);
 192                                 vrele(vp);
 193                         }
 194                 } else {
 195                         type = "none";
 196                         flags = 0;
 197                         ref_count = 0;
 198                         shadow_count = 0;
 199                 }
 200
 201                 /*
 202                  * format:
 203                  *  start, end, resident, private-resident, obj, access,
 204                  *  ref_count, shadow_count, flags, cow, needs_copy, type,
 205                  *  fullpath, charged, charged uid.
 206                  */
 207                 error = sbuf_printf(sb,
 208                     "0x%lx 0x%lx %d %d %p %s%s%s %d %d 0x%x %s %s %s %s %s %d\n",
 209                         (u_long)e_start, (u_long)e_end,
 210                         resident, privateresident,
 211 #ifdef COMPAT_FREEBSD32
 212                         wrap32 ? NULL : obj,    /* Hide 64 bit value */
 213 #else
 214                         obj,
 215 #endif
 216                         (e_prot & VM_PROT_READ)?"r":"-",
 217                         (e_prot & VM_PROT_WRITE)?"w":"-",
 218                         (e_prot & VM_PROT_EXECUTE)?"x":"-",
 219                         ref_count, shadow_count, flags,
 220                         (e_eflags & MAP_ENTRY_COW)?"COW":"NCOW",
 221                         (e_eflags & MAP_ENTRY_NEEDS_COPY)?"NC":"NNC",
 222                         type, fullpath,
 223                         cred ? "CH":"NCH", cred ? cred->cr_ruid : -1);
 224
 225                 if (freepath != NULL)
 226                         free(freepath, M_TEMP);
 227                 vm_map_lock_read(map);
 228                 if (error == -1) {
 229                         error = 0;
 230                         break;
 231                 }
 232                 if (last_timestamp != map->timestamp) {
 233                         /*
 234                          * Look again for the entry because the map was
 235                          * modified while it was unlocked.  Specifically,
 236                          * the entry may have been clipped, merged, or deleted.
 237                          */
 238                         vm_map_lookup_entry(map, e_end - 1, &tmp_entry);
 239                         entry = tmp_entry;
 240                 }
 241         }
 242         vm_map_unlock_read(map);
 243         vmspace_free(vm);
 244         return (error);
 245 }