New upstream version 0.7.2

[mirror_spl-debian.git] / module / spl / spl-err.c

diff --git a/module/spl/spl-err.c b/module/spl/spl-err.c
index 1d520282704c2f546336d70bbd04bba86402bc9b..2f66b6e23cb6fc5d4eecc72e34d97ebb9ab146d3 100644 (file)
--- a/module/spl/spl-err.c
+++ b/module/spl/spl-err.c
@@ -6,7 +6,7 @@
  *  UCRL-CODE-235197
  *
  *  This file is part of the SPL, Solaris Porting Layer.
- *  For details, see <http://github.com/behlendorf/spl/>.
+ *  For details, see <http://zfsonlinux.org/>.
  *
  *  The SPL is free software; you can redistribute it and/or modify it
  *  under the terms of the GNU General Public License as published by the
@@ -26,44 +26,95 @@
 
 #include <sys/sysmacros.h>
 #include <sys/cmn_err.h>
+#include <linux/ratelimit.h>
 
-#ifdef DEBUG_SUBSYSTEM
-#undef DEBUG_SUBSYSTEM
-#endif
+/*
+ * It is often useful to actually have the panic crash the node so you
+ * can then get notified of the event, get the crashdump for later
+ * analysis and other such goodies.
+ * But we would still default to the current default of not to do that.
+ */
+unsigned int spl_panic_halt;
+module_param(spl_panic_halt, uint, 0644);
+MODULE_PARM_DESC(spl_panic_halt,
+                "Cause kernel panic on assertion failures");
 
-#define DEBUG_SUBSYSTEM S_GENERIC
-
-#ifndef NDEBUG
-static char ce_prefix[CE_IGNORE][10] = { "", "NOTICE: ", "WARNING: ", "" };
-static char ce_suffix[CE_IGNORE][2] = { "", "\n", "\n", "" };
-#endif
+/*
+ * Limit the number of stack traces dumped to not more than 5 every
+ * 60 seconds to prevent denial-of-service attacks from debug code.
+ */
+DEFINE_RATELIMIT_STATE(dumpstack_ratelimit_state, 60 * HZ, 5);
 
 void
-vpanic(const char *fmt, va_list ap)
+spl_dumpstack(void)
 {
+       if (__ratelimit(&dumpstack_ratelimit_state)) {
+               printk("Showing stack for process %d\n", current->pid);
+               dump_stack();
+       }
+}
+EXPORT_SYMBOL(spl_dumpstack);
+
+int
+spl_panic(const char *file, const char *func, int line, const char *fmt, ...) {
+       const char *newfile;
        char msg[MAXMSGLEN];
+       va_list ap;
 
-       vsnprintf(msg, MAXMSGLEN - 1, fmt, ap);
-       panic("%s", msg);
-} /* vpanic() */
-EXPORT_SYMBOL(vpanic);
+       newfile = strrchr(file, '/');
+       if (newfile != NULL)
+               newfile = newfile + 1;
+       else
+               newfile = file;
+
+       va_start(ap, fmt);
+       (void) vsnprintf(msg, sizeof (msg), fmt, ap);
+       va_end(ap);
+
+       printk(KERN_EMERG "%s", msg);
+       printk(KERN_EMERG "PANIC at %s:%d:%s()\n", newfile, line, func);
+       if (spl_panic_halt)
+               panic("%s", msg);
+
+       spl_dumpstack();
+
+       /* Halt the thread to facilitate further debugging */
+       set_current_state(TASK_UNINTERRUPTIBLE);
+       while (1)
+               schedule();
+
+       /* Unreachable */
+       return (1);
+}
+EXPORT_SYMBOL(spl_panic);
 
 void
 vcmn_err(int ce, const char *fmt, va_list ap)
 {
        char msg[MAXMSGLEN];
 
-       if (ce == CE_PANIC)
-               vpanic(fmt, ap);
+       vsnprintf(msg, MAXMSGLEN - 1, fmt, ap);
 
-       if (ce != CE_NOTE) {
-               vsnprintf(msg, MAXMSGLEN - 1, fmt, ap);
+       switch (ce) {
+       case CE_IGNORE:
+               break;
+       case CE_CONT:
+               printk("%s", msg);
+               break;
+       case CE_NOTE:
+               printk(KERN_NOTICE "NOTICE: %s\n", msg);
+               break;
+       case CE_WARN:
+               printk(KERN_WARNING "WARNING: %s\n", msg);
+               break;
+       case CE_PANIC:
+               printk(KERN_EMERG "PANIC: %s\n", msg);
+               spl_dumpstack();
 
-               if (fmt[0] == '!')
-                       CDEBUG(D_INFO, "%s%s%s",
-                              ce_prefix[ce], msg, ce_suffix[ce]);
-               else
-                       CERROR("%s%s%s", ce_prefix[ce], msg, ce_suffix[ce]);
+               /* Halt the thread to facilitate further debugging */
+               set_current_state(TASK_UNINTERRUPTIBLE);
+               while (1)
+                       schedule();
        }
 } /* vcmn_err() */
 EXPORT_SYMBOL(vcmn_err);
@@ -78,4 +129,3 @@ cmn_err(int ce, const char *fmt, ...)
        va_end(ap);
 } /* cmn_err() */
 EXPORT_SYMBOL(cmn_err);
-