xref: /openbmc/linux/arch/s390/include/asm/stacktrace.h (revision c24c57a4)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_S390_STACKTRACE_H
3 #define _ASM_S390_STACKTRACE_H
4 
5 #include <linux/uaccess.h>
6 #include <linux/ptrace.h>
7 #include <asm/switch_to.h>
8 
9 enum stack_type {
10 	STACK_TYPE_UNKNOWN,
11 	STACK_TYPE_TASK,
12 	STACK_TYPE_IRQ,
13 	STACK_TYPE_NODAT,
14 	STACK_TYPE_RESTART,
15 };
16 
17 struct stack_info {
18 	enum stack_type type;
19 	unsigned long begin, end;
20 };
21 
22 const char *stack_type_name(enum stack_type type);
23 int get_stack_info(unsigned long sp, struct task_struct *task,
24 		   struct stack_info *info, unsigned long *visit_mask);
25 
26 static inline bool on_stack(struct stack_info *info,
27 			    unsigned long addr, size_t len)
28 {
29 	if (info->type == STACK_TYPE_UNKNOWN)
30 		return false;
31 	if (addr + len < addr)
32 		return false;
33 	return addr >= info->begin && addr + len <= info->end;
34 }
35 
36 static inline unsigned long get_stack_pointer(struct task_struct *task,
37 					      struct pt_regs *regs)
38 {
39 	if (regs)
40 		return (unsigned long) kernel_stack_pointer(regs);
41 	if (!task || task == current)
42 		return current_stack_pointer();
43 	return (unsigned long) task->thread.ksp;
44 }
45 
46 /*
47  * Stack layout of a C stack frame.
48  */
49 #ifndef __PACK_STACK
50 struct stack_frame {
51 	unsigned long back_chain;
52 	unsigned long empty1[5];
53 	unsigned long gprs[10];
54 	unsigned int  empty2[8];
55 };
56 #else
57 struct stack_frame {
58 	unsigned long empty1[5];
59 	unsigned int  empty2[8];
60 	unsigned long gprs[10];
61 	unsigned long back_chain;
62 };
63 #endif
64 
65 #define CALL_ARGS_0()							\
66 	register unsigned long r2 asm("2")
67 #define CALL_ARGS_1(arg1)						\
68 	register unsigned long r2 asm("2") = (unsigned long)(arg1)
69 #define CALL_ARGS_2(arg1, arg2)						\
70 	CALL_ARGS_1(arg1);						\
71 	register unsigned long r3 asm("3") = (unsigned long)(arg2)
72 #define CALL_ARGS_3(arg1, arg2, arg3)					\
73 	CALL_ARGS_2(arg1, arg2);					\
74 	register unsigned long r4 asm("4") = (unsigned long)(arg3)
75 #define CALL_ARGS_4(arg1, arg2, arg3, arg4)				\
76 	CALL_ARGS_3(arg1, arg2, arg3);					\
77 	register unsigned long r4 asm("5") = (unsigned long)(arg4)
78 #define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5)			\
79 	CALL_ARGS_4(arg1, arg2, arg3, arg4);				\
80 	register unsigned long r4 asm("6") = (unsigned long)(arg5)
81 
82 #define CALL_FMT_0 "=&d" (r2) :
83 #define CALL_FMT_1 "+&d" (r2) :
84 #define CALL_FMT_2 CALL_FMT_1 "d" (r3),
85 #define CALL_FMT_3 CALL_FMT_2 "d" (r4),
86 #define CALL_FMT_4 CALL_FMT_3 "d" (r5),
87 #define CALL_FMT_5 CALL_FMT_4 "d" (r6),
88 
89 #define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
90 #define CALL_CLOBBER_4 CALL_CLOBBER_5
91 #define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
92 #define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
93 #define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
94 #define CALL_CLOBBER_0 CALL_CLOBBER_1
95 
96 #define CALL_ON_STACK(fn, stack, nr, args...)				\
97 ({									\
98 	CALL_ARGS_##nr(args);						\
99 	unsigned long prev;						\
100 									\
101 	asm volatile(							\
102 		"	la	%[_prev],0(15)\n"			\
103 		"	la	15,0(%[_stack])\n"			\
104 		"	stg	%[_prev],%[_bc](15)\n"			\
105 		"	brasl	14,%[_fn]\n"				\
106 		"	la	15,0(%[_prev])\n"			\
107 		: [_prev] "=&a" (prev), CALL_FMT_##nr			\
108 		  [_stack] "a" (stack),					\
109 		  [_bc] "i" (offsetof(struct stack_frame, back_chain)),	\
110 		  [_fn] "X" (fn) : CALL_CLOBBER_##nr);			\
111 	r2;								\
112 })
113 
114 #endif /* _ASM_S390_STACKTRACE_H */
115