module/spl/spl-err.c

   1 /*****************************************************************************\
   2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
   3  *  Copyright (C) 2007 The Regents of the University of California.
   4  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
   5  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
   6  *  UCRL-CODE-235197
   7  *
   8  *  This file is part of the SPL, Solaris Porting Layer.
   9  *  For details, see <http://zfsonlinux.org/>.
  10  *
  11  *  The SPL is free software; you can redistribute it and/or modify it
  12  *  under the terms of the GNU General Public License as published by the
  13  *  Free Software Foundation; either version 2 of the License, or (at your
  14  *  option) any later version.
  15  *
  16  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  17  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19  *  for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License along
  22  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  23  *****************************************************************************
  24  *  Solaris Porting Layer (SPL) Error Implementation.
  25 \*****************************************************************************/
  26
  27 #include <sys/sysmacros.h>
  28 #include <sys/cmn_err.h>
  29 #include <linux/ratelimit.h>
  30
  31 /*
  32  * It is often useful to actually have the panic crash the node so you
  33  * can then get notified of the event, get the crashdump for later
  34  * analysis and other such goodies.
  35  * But we would still default to the current default of not to do that.
  36  */
  37 unsigned int spl_panic_halt;
  38 module_param(spl_panic_halt, uint, 0644);
  39 MODULE_PARM_DESC(spl_panic_halt,
  40                  "Cause kernel panic on assertion failures");
  41
  42 /*
  43  * Limit the number of stack traces dumped to not more than 5 every
  44  * 60 seconds to prevent denial-of-service attacks from debug code.
  45  */
  46 DEFINE_RATELIMIT_STATE(dumpstack_ratelimit_state, 60 * HZ, 5);
  47
  48 void
  49 spl_dumpstack(void)
  50 {
  51         if (__ratelimit(&dumpstack_ratelimit_state)) {
  52                 printk("Showing stack for process %d\n", current->pid);
  53                 dump_stack();
  54         }
  55 }
  56 EXPORT_SYMBOL(spl_dumpstack);
  57
  58 int
  59 spl_panic(const char *file, const char *func, int line, const char *fmt, ...) {
  60         const char *newfile;
  61         char msg[MAXMSGLEN];
  62         va_list ap;
  63
  64         newfile = strrchr(file, '/');
  65         if (newfile != NULL)
  66                 newfile = newfile + 1;
  67         else
  68                 newfile = file;
  69
  70         va_start(ap, fmt);
  71         (void) vsnprintf(msg, sizeof (msg), fmt, ap);
  72         va_end(ap);
  73
  74         printk(KERN_EMERG "%s", msg);
  75         printk(KERN_EMERG "PANIC at %s:%d:%s()\n", newfile, line, func);
  76         if (spl_panic_halt)
  77                 panic("%s", msg);
  78
  79         spl_dumpstack();
  80
  81         /* Halt the thread to facilitate further debugging */
  82         set_current_state(TASK_UNINTERRUPTIBLE);
  83         while (1)
  84                 schedule();
  85
  86         /* Unreachable */
  87         return (1);
  88 }
  89 EXPORT_SYMBOL(spl_panic);
  90
  91 void
  92 vcmn_err(int ce, const char *fmt, va_list ap)
  93 {
  94         char msg[MAXMSGLEN];
  95
  96         vsnprintf(msg, MAXMSGLEN - 1, fmt, ap);
  97
  98         switch (ce) {
  99         case CE_IGNORE:
 100                 break;
 101         case CE_CONT:
 102                 printk("%s", msg);
 103                 break;
 104         case CE_NOTE:
 105                 printk(KERN_NOTICE "NOTICE: %s\n", msg);
 106                 break;
 107         case CE_WARN:
 108                 printk(KERN_WARNING "WARNING: %s\n", msg);
 109                 break;
 110         case CE_PANIC:
 111                 printk(KERN_EMERG "PANIC: %s\n", msg);
 112                 spl_dumpstack();
 113
 114                 /* Halt the thread to facilitate further debugging */
 115                 set_current_state(TASK_UNINTERRUPTIBLE);
 116                 while (1)
 117                         schedule();
 118         }
 119 } /* vcmn_err() */
 120 EXPORT_SYMBOL(vcmn_err);
 121
 122 void
 123 cmn_err(int ce, const char *fmt, ...)
 124 {
 125         va_list ap;
 126
 127         va_start(ap, fmt);
 128         vcmn_err(ce, fmt, ap);
 129         va_end(ap);
 130 } /* cmn_err() */
 131 EXPORT_SYMBOL(cmn_err);