usr/src/cmd/mdb/common/modules/mm/mm.c

   1 /*
   2  * This file and its contents are supplied under the terms of the
   3  * Common Development and Distribution License ("CDDL"), version 1.0.
   4  * You may only use this file in accordance with the terms of version
   5  * 1.0 of the CDDL.
   6  *
   7  * A full copy of the text of the CDDL should have accompanied this
   8  * source.  A copy of the CDDL is also available via the Internet at
   9  * http://www.illumos.org/license/CDDL.
  10  */
  11
  12 /*
  13  * Copyright (c) 2015, Joyent, Inc.  All rights reserved.
  14  */
  15
  16 #include <sys/mdb_modapi.h>
  17 #include <sys/time.h>
  18 #include <sys/mem.h>
  19
  20 typedef struct kmemlog_walk {
  21         uintptr_t kmlw_addr;
  22         mm_logentry_t *kmlw_entries;
  23         int kmlw_nentries;
  24         int kmlw_entry;
  25         int kmlw_oldest;
  26 } kmemlog_walk_t;
  27
  28 static int
  29 kmemlog_walk_init(mdb_walk_state_t *wsp)
  30 {
  31         kmemlog_walk_t *kw;
  32         GElf_Sym sym;
  33
  34         if (mdb_lookup_by_name("mm_kmemlog", &sym) != 0) {
  35                 mdb_warn("couldn't find symbol 'mm_kmemlog'");
  36                 return (WALK_ERR);
  37         }
  38
  39         kw = mdb_zalloc(sizeof (kmemlog_walk_t), UM_SLEEP);
  40         kw->kmlw_entries = mdb_zalloc(sym.st_size, UM_SLEEP);
  41         kw->kmlw_addr = sym.st_value;
  42
  43         if (mdb_vread(kw->kmlw_entries, sym.st_size, sym.st_value) == -1) {
  44                 mdb_warn("couldn't read log at %p", sym.st_value);
  45                 mdb_free(kw->kmlw_entries, sym.st_size);
  46                 mdb_free(kw, sizeof (kmemlog_walk_t));
  47                 return (WALK_ERR);
  48         }
  49
  50         kw->kmlw_nentries = sym.st_size / sizeof (mm_logentry_t);
  51
  52         mdb_readvar(&kw->kmlw_entry, "mm_kmemlogent");
  53         kw->kmlw_oldest = kw->kmlw_entry;
  54         wsp->walk_data = kw;
  55
  56         return (WALK_NEXT);
  57 }
  58
  59 static int
  60 kmemlog_walk_step(mdb_walk_state_t *wsp)
  61 {
  62         kmemlog_walk_t *kw = wsp->walk_data;
  63         mm_logentry_t *ent;
  64         int rval = WALK_NEXT;
  65
  66         ent = &kw->kmlw_entries[kw->kmlw_entry];
  67
  68         if (++kw->kmlw_entry == kw->kmlw_nentries)
  69                 kw->kmlw_entry = 0;
  70
  71         if (ent->mle_hrtime != 0) {
  72                 rval = wsp->walk_callback(kw->kmlw_addr + ((uintptr_t)ent -
  73                     (uintptr_t)kw->kmlw_entries), ent, wsp->walk_cbdata);
  74         }
  75
  76         if (rval == WALK_NEXT && kw->kmlw_entry == kw->kmlw_oldest)
  77                 return (WALK_DONE);
  78
  79         return (rval);
  80 }
  81
  82 static void
  83 kmemlog_walk_fini(mdb_walk_state_t *wsp)
  84 {
  85         kmemlog_walk_t *kw = wsp->walk_data;
  86
  87         mdb_free(kw->kmlw_entries, kw->kmlw_nentries * sizeof (mm_logentry_t));
  88         mdb_free(kw, sizeof (kmemlog_walk_t));
  89 }
  90
  91 static int
  92 kmemlog(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
  93 {
  94         mm_logentry_t ent;
  95
  96         if (!(flags & DCMD_ADDRSPEC)) {
  97                 if (mdb_walk_dcmd("kmemlog", "kmemlog", argc, argv) == -1) {
  98                         mdb_warn("can't walk 'kmemlog'");
  99                         return (DCMD_ERR);
 100                 }
 101                 return (DCMD_OK);
 102         }
 103
 104         if (DCMD_HDRSPEC(flags)) {
 105                 mdb_printf("%?s %-20s %?s %5s %s\n",
 106                     "ADDR", "TIME", "VADDR", "PID", "PSARGS");
 107         }
 108
 109         if (mdb_vread(&ent, sizeof (ent), addr) == -1) {
 110                 mdb_warn("can't read mm_logentry_t at %p", addr);
 111                 return (DCMD_ERR);
 112         }
 113
 114         mdb_printf("%?p %-20Y %?p %5d %s\n",
 115             addr, ent.mle_hrestime.tv_sec, ent.mle_vaddr, ent.mle_pid,
 116             ent.mle_psargs);
 117
 118         return (DCMD_OK);
 119 }
 120
 121 static const mdb_dcmd_t dcmds[] = {
 122         { "kmemlog", NULL, "print log of writes via /dev/kmem", kmemlog },
 123         { NULL }
 124 };
 125
 126 static const mdb_walker_t walkers[] = {
 127         { "kmemlog", "walk entries in /dev/kmem write log",
 128                 kmemlog_walk_init, kmemlog_walk_step, kmemlog_walk_fini },
 129         { NULL }
 130 };
 131
 132 static const mdb_modinfo_t modinfo = {
 133         MDB_API_VERSION, dcmds, walkers
 134 };
 135
 136 const mdb_modinfo_t *
 137 _mdb_init(void)
 138 {
 139         return (&modinfo);
 140 }