[MIPS] Improve unwind_stack()
This patch allows unwind_stack() to return ra for leaf function.
But it tries to detects cases where get_frame_info() wrongly
consider nested function as a leaf one.
It also pass 'unsinged long *sp' instead of 'unsigned long **sp'
as second parameter. The code looks cleaner.
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 303f008..ab77034 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -74,8 +74,9 @@
void (*board_bind_eic_interrupt)(int irq, int regset);
-static void show_raw_backtrace(unsigned long *sp)
+static void show_raw_backtrace(unsigned long reg29)
{
+ unsigned long *sp = (unsigned long *)reg29;
unsigned long addr;
printk("Call Trace:");
@@ -99,30 +100,29 @@
}
__setup("raw_show_trace", set_raw_show_trace);
-extern unsigned long unwind_stack(struct task_struct *task,
- unsigned long **sp, unsigned long pc);
+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 = (long *)regs->regs[29];
+ unsigned long sp = regs->regs[29];
+ unsigned long ra = regs->regs[31];
unsigned long pc = regs->cp0_epc;
- int top = 1;
if (raw_show_trace || !__kernel_text_address(pc)) {
show_raw_backtrace(sp);
return;
}
printk("Call Trace:\n");
- while (__kernel_text_address(pc)) {
+ do {
print_ip_sym(pc);
- pc = unwind_stack(task, &sp, pc);
- if (top && pc == 0)
- pc = regs->regs[31]; /* leaf? */
- top = 0;
- }
+ pc = unwind_stack(task, &sp, pc, ra);
+ ra = 0;
+ } while (pc);
printk("\n");
}
#else
-#define show_backtrace(task, r) show_raw_backtrace((long *)(r)->regs[29]);
+#define show_backtrace(task, r) show_raw_backtrace((r)->regs[29]);
#endif
/*