[PATCH] i386: Do backtrace fallback too

Similar patch to earlier x86-64 patch. When the dwarf2 unwinder fails
dump the left over stack with the old unwinder.

Also some clarifications in the headers.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/traps.c

@@ -187,10 +187,21 @@ static void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
 			if (unwind_init_blocked(&info, task) == 0)
 				unw_ret = show_trace_unwind(&info, log_lvl);
 		}
-		if (unw_ret > 0) {
-			if (call_trace > 0)
+		if (unw_ret > 0 && !arch_unw_user_mode(&info)) {
+#ifdef CONFIG_STACK_UNWIND
+			print_symbol("DWARF2 unwinder stuck at %s\n",
+				     UNW_PC(info.regs));
+			if (call_trace == 1) {
+				printk("Leftover inexact backtrace:\n");
+				if (UNW_SP(info.regs))
+					stack = (void *)UNW_SP(info.regs);
+			} else if (call_trace > 1)
 				return;
-			printk("%sLegacy call trace:\n", log_lvl);
+			else
+				printk("Full inexact backtrace again:\n");
+#else
+			printk("Inexact backtrace:\n");
+#endif
 		}
 	}