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 /* BEGIN CSTYLED */
  38 unsigned int spl_panic_halt;
  39 module_param(spl_panic_halt, uint, 0644);
  40 MODULE_PARM_DESC(spl_panic_halt, "Cause kernel panic on assertion failures");
  41 /* END CSTYLED */
  42
  43 /*
  44  * Limit the number of stack traces dumped to not more than 5 every
  45  * 60 seconds to prevent denial-of-service attacks from debug code.
  46  */
  47 DEFINE_RATELIMIT_STATE(dumpstack_ratelimit_state, 60 * HZ, 5);
  48
  49 void
  50 spl_dumpstack(void)
  51 {
  52         if (__ratelimit(&dumpstack_ratelimit_state)) {
  53                 printk("Showing stack for process %d\n", current->pid);
  54                 dump_stack();
  55         }
  56 }
  57 EXPORT_SYMBOL(spl_dumpstack);
  58
  59 int
  60 spl_panic(const char *file, const char *func, int line, const char *fmt, ...)
  61 {
  62         const char *newfile;
  63         char msg[MAXMSGLEN];
  64         va_list ap;
  65
  66         newfile = strrchr(file, '/');
  67         if (newfile != NULL)
  68                 newfile = newfile + 1;
  69         else
  70                 newfile = file;
  71
  72         va_start(ap, fmt);
  73         (void) vsnprintf(msg, sizeof (msg), fmt, ap);
  74         va_end(ap);
  75
  76         printk(KERN_EMERG "%s", msg);
  77         printk(KERN_EMERG "PANIC at %s:%d:%s()\n", newfile, line, func);
  78         if (spl_panic_halt)
  79                 panic("%s", msg);
  80
  81         spl_dumpstack();
  82
  83         /* Halt the thread to facilitate further debugging */
  84         set_current_state(TASK_UNINTERRUPTIBLE);
  85         while (1)
  86                 schedule();
  87
  88         /* Unreachable */
  89         return (1);
  90 }
  91 EXPORT_SYMBOL(spl_panic);
  92
  93 void
  94 vcmn_err(int ce, const char *fmt, va_list ap)
  95 {
  96         char msg[MAXMSGLEN];
  97
  98         vsnprintf(msg, MAXMSGLEN - 1, fmt, ap);
  99
 100         switch (ce) {
 101         case CE_IGNORE:
 102                 break;
 103         case CE_CONT:
 104                 printk("%s", msg);
 105                 break;
 106         case CE_NOTE:
 107                 printk(KERN_NOTICE "NOTICE: %s\n", msg);
 108                 break;
 109         case CE_WARN:
 110                 printk(KERN_WARNING "WARNING: %s\n", msg);
 111                 break;
 112         case CE_PANIC:
 113                 printk(KERN_EMERG "PANIC: %s\n", msg);
 114                 spl_dumpstack();
 115
 116                 /* Halt the thread to facilitate further debugging */
 117                 set_current_state(TASK_UNINTERRUPTIBLE);
 118                 while (1)
 119                         schedule();
 120         }
 121 } /* vcmn_err() */
 122 EXPORT_SYMBOL(vcmn_err);
 123
 124 void
 125 cmn_err(int ce, const char *fmt, ...)
 126 {
 127         va_list ap;
 128
 129         va_start(ap, fmt);
 130         vcmn_err(ce, fmt, ap);
 131         va_end(ap);
 132 } /* cmn_err() */
 133 EXPORT_SYMBOL(cmn_err);