usr/src/cmd/mdb/demo/common/example2.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 1998-1999 by Sun Microsystems, Inc.
  24  * All rights reserved.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include <sys/mdb_modapi.h>
  30 #include <sys/proc.h>
  31
  32 /*
  33  * Initialize the proc_t walker by either using the given starting address,
  34  * or reading the value of the kernel's practive pointer.  We also allocate
  35  * a proc_t for storage, and save this using the walk_data pointer.
  36  */
  37 static int
  38 sp_walk_init(mdb_walk_state_t *wsp)
  39 {
  40         if (wsp->walk_addr == NULL &&
  41             mdb_readvar(&wsp->walk_addr, "practive") == -1) {
  42                 mdb_warn("failed to read 'practive'");
  43                 return (WALK_ERR);
  44         }
  45
  46         wsp->walk_data = mdb_alloc(sizeof (proc_t), UM_SLEEP);
  47         return (WALK_NEXT);
  48 }
  49
  50 /*
  51  * At each step, read a proc_t into our private storage, and then invoke
  52  * the callback function.  We terminate when we reach a NULL p_next pointer.
  53  */
  54 static int
  55 sp_walk_step(mdb_walk_state_t *wsp)
  56 {
  57         int status;
  58
  59         if (wsp->walk_addr == NULL)
  60                 return (WALK_DONE);
  61
  62         if (mdb_vread(wsp->walk_data, sizeof (proc_t), wsp->walk_addr) == -1) {
  63                 mdb_warn("failed to read proc at %p", wsp->walk_addr);
  64                 return (WALK_DONE);
  65         }
  66
  67         status = wsp->walk_callback(wsp->walk_addr, wsp->walk_data,
  68             wsp->walk_cbdata);
  69
  70         wsp->walk_addr = (uintptr_t)(((proc_t *)wsp->walk_data)->p_next);
  71         return (status);
  72 }
  73
  74 /*
  75  * The walker's fini function is invoked at the end of each walk.  Since we
  76  * dynamically allocated a proc_t in sp_walk_init, we must free it now.
  77  */
  78 static void
  79 sp_walk_fini(mdb_walk_state_t *wsp)
  80 {
  81         mdb_free(wsp->walk_data, sizeof (proc_t));
  82 }
  83
  84 static int
  85 simple_ps(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
  86 {
  87         struct pid pid;
  88         proc_t p;
  89
  90         if (argc != 0)
  91                 return (DCMD_USAGE);
  92
  93         /*
  94          * If no proc_t address was specified on the command line, we can
  95          * print out all processes by invoking the walker, using this
  96          * dcmd itself as the callback.
  97          */
  98         if (!(flags & DCMD_ADDRSPEC)) {
  99                 if (mdb_walk_dcmd("simple_proc", "simple_ps",
 100                     argc, argv) == -1) {
 101                         mdb_warn("failed to walk 'simple_proc'");
 102                         return (DCMD_ERR);
 103                 }
 104                 return (DCMD_OK);
 105         }
 106
 107         /*
 108          * If this is the first invocation of the command, print a nice
 109          * header line for the output that will follow.
 110          */
 111         if (DCMD_HDRSPEC(flags))
 112                 mdb_printf("%5s %s\n", "PID", "COMM");
 113
 114         /*
 115          * For each process, we just need to read the proc_t struct, read
 116          * the pid struct addressed by p_pidp, and then print out the pid
 117          * and the command name.
 118          */
 119         if (mdb_vread(&p, sizeof (p), addr) == sizeof (p)) {
 120
 121                 if (mdb_vread(&pid, sizeof (pid),
 122                     (uintptr_t)p.p_pidp) == sizeof (pid))
 123                         mdb_printf("%5d %s\n", pid.pid_id, p.p_user.u_comm);
 124                 else
 125                         mdb_warn("failed to read struct pid at %p", p.p_pidp);
 126         } else
 127                 mdb_warn("failed to read process at %p", addr);
 128
 129         return (DCMD_OK);
 130 }
 131
 132 /*
 133  * MDB module linkage information:
 134  *
 135  * We declare a list of structures describing our dcmds, a list of structures
 136  * describing our walkers, and a function named _mdb_init to return a pointer
 137  * to our module information.
 138  */
 139
 140 static const mdb_dcmd_t dcmds[] = {
 141         { "simple_ps", NULL, "simple process list", simple_ps },
 142         { NULL }
 143 };
 144
 145 static const mdb_walker_t walkers[] = {
 146         { "simple_proc", "walk list of proc_t structures",
 147                 sp_walk_init, sp_walk_step, sp_walk_fini },
 148         { NULL }
 149 };
 150
 151 static const mdb_modinfo_t modinfo = {
 152         MDB_API_VERSION, dcmds, walkers
 153 };
 154
 155 const mdb_modinfo_t *
 156 _mdb_init(void)
 157 {
 158         return (&modinfo);
 159 }