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