1 files changed, 109 insertions, 37 deletions

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 954a198494e..e51d8fd9a15 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -20,6 +20,7 @@
 #include <linux/spinlock.h>
 #include <linux/kallsyms.h>
 #include <linux/bootmem.h>
+#include <linux/interrupt.h>
 
 #include <asm/bootinfo.h>
 #include <asm/branch.h>
@@ -72,28 +73,68 @@ void (*board_nmi_handler_setup)(void);
 void (*board_ejtag_handler_setup)(void);
 void (*board_bind_eic_interrupt)(int irq, int regset);
 
-/*
- * These constant is for searching for possible module text segments.
- * MODULE_RANGE is a guess of how much space is likely to be vmalloced.
- */
-#define MODULE_RANGE (8*1024*1024)
+
+static void show_raw_backtrace(unsigned long reg29)
+{
+	unsigned long *sp = (unsigned long *)reg29;
+	unsigned long addr;
+
+	printk("Call Trace:");
+#ifdef CONFIG_KALLSYMS
+	printk("\n");
+#endif
+	while (!kstack_end(sp)) {
+		addr = *sp++;
+		if (__kernel_text_address(addr))
+			print_ip_sym(addr);
+	}
+	printk("\n");
+}
+
+#ifdef CONFIG_KALLSYMS
+static int raw_show_trace;
+static int __init set_raw_show_trace(char *str)
+{
+	raw_show_trace = 1;
+	return 1;
+}
+__setup("raw_show_trace", set_raw_show_trace);
+
+extern unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
+				  unsigned long pc, unsigned long ra);
+
+static void show_backtrace(struct task_struct *task, struct pt_regs *regs)
+{
+	unsigned long sp = regs->regs[29];
+	unsigned long ra = regs->regs[31];
+	unsigned long pc = regs->cp0_epc;
+
+	if (raw_show_trace || !__kernel_text_address(pc)) {
+		show_raw_backtrace(sp);
+		return;
+	}
+	printk("Call Trace:\n");
+	do {
+		print_ip_sym(pc);
+		pc = unwind_stack(task, &sp, pc, ra);
+		ra = 0;
+	} while (pc);
+	printk("\n");
+}
+#else
+#define show_backtrace(task, r) show_raw_backtrace((r)->regs[29]);
+#endif
 
 /*
  * This routine abuses get_user()/put_user() to reference pointers
  * with at least a bit of error checking ...
  */
-void show_stack(struct task_struct *task, unsigned long *sp)
+static void show_stacktrace(struct task_struct *task, struct pt_regs *regs)
 {
 	const int field = 2 * sizeof(unsigned long);
 	long stackdata;
 	int i;
-
-	if (!sp) {
-		if (task && task != current)
-			sp = (unsigned long *) task->thread.reg29;
-		else
-			sp = (unsigned long *) &sp;
-	}
+	unsigned long *sp = (unsigned long *)regs->regs[29];
 
 	printk("Stack :");
 	i = 0;
@@ -114,32 +155,48 @@ void show_stack(struct task_struct *task, unsigned long *sp)
 		i++;
 	}
 	printk("\n");
+	show_backtrace(task, regs);
 }
 
-void show_trace(struct task_struct *task, unsigned long *stack)
+static __always_inline void prepare_frametrace(struct pt_regs *regs)
 {
-	const int field = 2 * sizeof(unsigned long);
-	unsigned long addr;
-
-	if (!stack) {
-		if (task && task != current)
-			stack = (unsigned long *) task->thread.reg29;
-		else
-			stack = (unsigned long *) &stack;
-	}
-
-	printk("Call Trace:");
-#ifdef CONFIG_KALLSYMS
-	printk("\n");
+	__asm__ __volatile__(
+		".set push\n\t"
+		".set noat\n\t"
+#ifdef CONFIG_64BIT
+		"1: dla $1, 1b\n\t"
+		"sd $1, %0\n\t"
+		"sd $29, %1\n\t"
+		"sd $31, %2\n\t"
+#else
+		"1: la $1, 1b\n\t"
+		"sw $1, %0\n\t"
+		"sw $29, %1\n\t"
+		"sw $31, %2\n\t"
 #endif
-	while (!kstack_end(stack)) {
-		addr = *stack++;
-		if (__kernel_text_address(addr)) {
-			printk(" [<%0*lx>] ", field, addr);
-			print_symbol("%s\n", addr);
+		".set pop\n\t"
+		: "=m" (regs->cp0_epc),
+		"=m" (regs->regs[29]), "=m" (regs->regs[31])
+		: : "memory");
+}
+
+void show_stack(struct task_struct *task, unsigned long *sp)
+{
+	struct pt_regs regs;
+	if (sp) {
+		regs.regs[29] = (unsigned long)sp;
+		regs.regs[31] = 0;
+		regs.cp0_epc = 0;
+	} else {
+		if (task && task != current) {
+			regs.regs[29] = task->thread.reg29;
+			regs.regs[31] = 0;
+			regs.cp0_epc = task->thread.reg31;
+		} else {
+			prepare_frametrace(&regs);
 		}
 	}
-	printk("\n");
+	show_stacktrace(task, &regs);
 }
 
 /*
@@ -147,9 +204,15 @@ void show_trace(struct task_struct *task, unsigned long *stack)
  */
 void dump_stack(void)
 {
-	unsigned long stack;
+	struct pt_regs regs;
 
-	show_trace(current, &stack);
+	/*
+	 * Remove any garbage that may be in regs (specially func
+	 * addresses) to avoid show_raw_backtrace() to report them
+	 */
+	memset(&regs, 0, sizeof(regs));
+	prepare_frametrace(&regs);
+	show_backtrace(current, &regs);
 }
 
 EXPORT_SYMBOL(dump_stack);
@@ -268,8 +331,7 @@ void show_registers(struct pt_regs *regs)
 	print_modules();
 	printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
 	        current->comm, current->pid, current_thread_info(), current);
-	show_stack(current, (long *) regs->regs[29]);
-	show_trace(current, (long *) regs->regs[29]);
+	show_stacktrace(current, regs);
 	show_code((unsigned int *) regs->cp0_epc);
 	printk("\n");
 }
@@ -292,6 +354,16 @@ NORET_TYPE void ATTRIB_NORET die(const char * str, struct pt_regs * regs)
 	printk("%s[#%d]:\n", str, ++die_counter);
 	show_registers(regs);
 	spin_unlock_irq(&die_lock);
+
+	if (in_interrupt())
+		panic("Fatal exception in interrupt");
+
+	if (panic_on_oops) {
+		printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
+		ssleep(5);
+		panic("Fatal exception");
+	}
+
 	do_exit(SIGSEGV);
 }