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  * $FreeBSD$
  38  */
  39
  40 #include "opt_compat.h"
  41
  42 #include <sys/param.h>
  43 #include <sys/systm.h>
  44 #include <sys/lock.h>
  45 #include <sys/filedesc.h>
  46 #include <sys/malloc.h>
  47 #include <sys/mount.h>
  48 #include <sys/proc.h>
  49 #include <sys/resourcevar.h>
  50 #include <sys/rwlock.h>
  51 #include <sys/sbuf.h>
  52 #ifdef COMPAT_FREEBSD32
  53 #include <sys/sysent.h>
  54 #endif
  55 #include <sys/uio.h>
  56 #include <sys/vnode.h>
  57
  58 #include <fs/pseudofs/pseudofs.h>
  59 #include <fs/procfs/procfs.h>
  60
  61 #include <vm/vm.h>
  62 #include <vm/vm_extern.h>
  63 #include <vm/pmap.h>
  64 #include <vm/vm_map.h>
  65 #include <vm/vm_page.h>
  66 #include <vm/vm_object.h>
  67
  68 #define MEBUFFERSIZE 256
  69
  70 /*
  71  * The map entries can *almost* be read with programs like cat.  However,
  72  * large maps need special programs to read.  It is not easy to implement
  73  * a program that can sense the required size of the buffer, and then
  74  * subsequently do a read with the appropriate size.  This operation cannot
  75  * be atomic.  The best that we can do is to allow the program to do a read
  76  * with an arbitrarily large buffer, and return as much as we can.  We can
  77  * return an error code if the buffer is too small (EFBIG), then the program
  78  * can try a bigger buffer.
  79  */
  80 int
  81 procfs_doprocmap(PFS_FILL_ARGS)
  82 {
  83         struct vmspace *vm;
  84         vm_map_t map;
  85         vm_map_entry_t entry, tmp_entry;
  86         struct vnode *vp;
  87         char *fullpath, *freepath, *type;
  88         struct ucred *cred;
  89         vm_object_t obj, tobj, lobj;
  90         int error, privateresident, ref_count, resident, shadow_count, flags;
  91         vm_offset_t e_start, e_end;
  92         vm_eflags_t e_eflags;
  93         vm_prot_t e_prot;
  94         unsigned int last_timestamp;
  95         bool super;
  96 #ifdef COMPAT_FREEBSD32
  97         bool wrap32;
  98 #endif
  99
 100         PROC_LOCK(p);
 101         error = p_candebug(td, p);
 102         PROC_UNLOCK(p);
 103         if (error)
 104                 return (error);
 105
 106         if (uio->uio_rw != UIO_READ)
 107                 return (EOPNOTSUPP);
 108
 109 #ifdef COMPAT_FREEBSD32
 110         wrap32 = false;
 111         if (SV_CURPROC_FLAG(SV_ILP32)) {
 112                 if (!(SV_PROC_FLAG(p, SV_ILP32)))
 113                         return (EOPNOTSUPP);
 114                 wrap32 = true;
 115         }
 116 #endif
 117
 118         vm = vmspace_acquire_ref(p);
 119         if (vm == NULL)
 120                 return (ESRCH);
 121         map = &vm->vm_map;
 122         vm_map_lock_read(map);
 123         for (entry = map->header.next; entry != &map->header;
 124              entry = entry->next) {
 125                 if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
 126                         continue;
 127
 128                 e_eflags = entry->eflags;
 129                 e_prot = entry->protection;
 130                 e_start = entry->start;
 131                 e_end = entry->end;
 132                 privateresident = 0;
 133                 resident = 0;
 134                 obj = entry->object.vm_object;
 135                 if (obj != NULL) {
 136                         VM_OBJECT_RLOCK(obj);
 137                         if (obj->shadow_count == 1)
 138                                 privateresident = obj->resident_page_count;
 139                 }
 140                 cred = (entry->cred) ? entry->cred : (obj ? obj->cred : NULL);
 141
 142                 for (lobj = tobj = obj; tobj != NULL;
 143                     tobj = tobj->backing_object) {
 144                         if (tobj != obj)
 145                                 VM_OBJECT_RLOCK(tobj);
 146                         lobj = tobj;
 147                 }
 148                 if (obj != NULL)
 149                         kern_proc_vmmap_resident(map, entry, &resident, &super);
 150                 for (tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 151                         if (tobj != obj && tobj != lobj)
 152                                 VM_OBJECT_RUNLOCK(tobj);
 153                 }
 154                 last_timestamp = map->timestamp;
 155                 vm_map_unlock_read(map);
 156
 157                 freepath = NULL;
 158                 fullpath = "-";
 159                 if (lobj) {
 160                         vp = NULL;
 161                         switch (lobj->type) {
 162                         default:
 163                         case OBJT_DEFAULT:
 164                                 type = "default";
 165                                 break;
 166                         case OBJT_VNODE:
 167                                 type = "vnode";
 168                                 vp = lobj->handle;
 169                                 vref(vp);
 170                                 break;
 171                         case OBJT_SWAP:
 172                                 if ((lobj->flags & OBJ_TMPFS_NODE) != 0) {
 173                                         type = "vnode";
 174                                         if ((lobj->flags & OBJ_TMPFS) != 0) {
 175                                                 vp = lobj->un_pager.swp.swp_tmpfs;
 176                                                 vref(vp);
 177                                         }
 178                                 } else {
 179                                         type = "swap";
 180                                 }
 181                                 break;
 182                         case OBJT_SG:
 183                         case OBJT_DEVICE:
 184                                 type = "device";
 185                                 break;
 186                         }
 187                         if (lobj != obj)
 188                                 VM_OBJECT_RUNLOCK(lobj);
 189
 190                         flags = obj->flags;
 191                         ref_count = obj->ref_count;
 192                         shadow_count = obj->shadow_count;
 193                         VM_OBJECT_RUNLOCK(obj);
 194                         if (vp != NULL) {
 195                                 vn_fullpath(td, vp, &fullpath, &freepath);
 196                                 vrele(vp);
 197                         }
 198                 } else {
 199                         type = "none";
 200                         flags = 0;
 201                         ref_count = 0;
 202                         shadow_count = 0;
 203                 }
 204
 205                 /*
 206                  * format:
 207                  *  start, end, resident, private resident, cow, access, type,
 208                  *         charged, charged uid.
 209                  */
 210                 error = sbuf_printf(sb,
 211                     "0x%lx 0x%lx %d %d %p %s%s%s %d %d 0x%x %s %s %s %s %s %d\n",
 212                         (u_long)e_start, (u_long)e_end,
 213                         resident, privateresident,
 214 #ifdef COMPAT_FREEBSD32
 215                         wrap32 ? NULL : obj,    /* Hide 64 bit value */
 216 #else
 217                         obj,
 218 #endif
 219                         (e_prot & VM_PROT_READ)?"r":"-",
 220                         (e_prot & VM_PROT_WRITE)?"w":"-",
 221                         (e_prot & VM_PROT_EXECUTE)?"x":"-",
 222                         ref_count, shadow_count, flags,
 223                         (e_eflags & MAP_ENTRY_COW)?"COW":"NCOW",
 224                         (e_eflags & MAP_ENTRY_NEEDS_COPY)?"NC":"NNC",
 225                         type, fullpath,
 226                         cred ? "CH":"NCH", cred ? cred->cr_ruid : -1);
 227
 228                 if (freepath != NULL)
 229                         free(freepath, M_TEMP);
 230                 vm_map_lock_read(map);
 231                 if (error == -1) {
 232                         error = 0;
 233                         break;
 234                 }
 235                 if (last_timestamp != map->timestamp) {
 236                         /*
 237                          * Look again for the entry because the map was
 238                          * modified while it was unlocked.  Specifically,
 239                          * the entry may have been clipped, merged, or deleted.
 240                          */
 241                         vm_map_lookup_entry(map, e_end - 1, &tmp_entry);
 242                         entry = tmp_entry;
 243                 }
 244         }
 245         vm_map_unlock_read(map);
 246         vmspace_free(vm);
 247         return (error);
 248 }