1#ifndef _ASM_STACKTRACE_H
2#define _ASM_STACKTRACE_H
3
4#include <asm/ptrace.h>
5
6#ifdef CONFIG_KALLSYMS
7extern int raw_show_trace;
8extern unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
9				  unsigned long pc, unsigned long *ra);
10extern unsigned long unwind_stack_by_address(unsigned long stack_page,
11					     unsigned long *sp,
12					     unsigned long pc,
13					     unsigned long *ra);
14#else
15#define raw_show_trace 1
16static inline unsigned long unwind_stack(struct task_struct *task,
17	unsigned long *sp, unsigned long pc, unsigned long *ra)
18{
19	return 0;
20}
21#endif
22
23static __always_inline void prepare_frametrace(struct pt_regs *regs)
24{
25#ifndef CONFIG_KALLSYMS
26	/*
27	 * Remove any garbage that may be in regs (specially func
28	 * addresses) to avoid show_raw_backtrace() to report them
29	 */
30	memset(regs, 0, sizeof(*regs));
31#endif
32	__asm__ __volatile__(
33		".set push\n\t"
34		".set noat\n\t"
35#ifdef CONFIG_64BIT
36		"1: dla $1, 1b\n\t"
37		"sd $1, %0\n\t"
38		"sd $29, %1\n\t"
39		"sd $31, %2\n\t"
40#else
41		"1: la $1, 1b\n\t"
42		"sw $1, %0\n\t"
43		"sw $29, %1\n\t"
44		"sw $31, %2\n\t"
45#endif
46		".set pop\n\t"
47		: "=m" (regs->cp0_epc),
48		"=m" (regs->regs[29]), "=m" (regs->regs[31])
49		: : "memory");
50}
51
52#endif /* _ASM_STACKTRACE_H */
53