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 STACK_TYPE_MCCK,
16 };
17
18 struct stack_info {
19 enum stack_type type;
20 unsigned long begin, end;
21 };
22
23 const char *stack_type_name(enum stack_type type);
24 int get_stack_info(unsigned long sp, struct task_struct *task,
25 struct stack_info *info, unsigned long *visit_mask);
26
on_stack(struct stack_info * info,unsigned long addr,size_t len)27 static inline bool on_stack(struct stack_info *info,
28 unsigned long addr, size_t len)
29 {
30 if (info->type == STACK_TYPE_UNKNOWN)
31 return false;
32 if (addr + len < addr)
33 return false;
34 return addr >= info->begin && addr + len <= info->end;
35 }
36
get_stack_pointer(struct task_struct * task,struct pt_regs * regs)37 static __always_inline unsigned long get_stack_pointer(struct task_struct *task,
38 struct pt_regs *regs)
39 {
40 if (regs)
41 return (unsigned long) kernel_stack_pointer(regs);
42 if (task == current)
43 return current_stack_pointer();
44 return (unsigned long) task->thread.ksp;
45 }
46
47 /*
48 * Stack layout of a C stack frame.
49 */
50 #ifndef __PACK_STACK
51 struct stack_frame {
52 unsigned long back_chain;
53 unsigned long empty1[5];
54 unsigned long gprs[10];
55 unsigned int empty2[8];
56 };
57 #else
58 struct stack_frame {
59 unsigned long empty1[5];
60 unsigned int empty2[8];
61 unsigned long gprs[10];
62 unsigned long back_chain;
63 };
64 #endif
65
66 /*
67 * Unlike current_stack_pointer() which simply returns current value of %r15
68 * current_frame_address() returns function stack frame address, which matches
69 * %r15 upon function invocation. It may differ from %r15 later if function
70 * allocates stack for local variables or new stack frame to call other
71 * functions.
72 */
73 #define current_frame_address() \
74 ((unsigned long)__builtin_frame_address(0) - \
75 offsetof(struct stack_frame, back_chain))
76
77 #define CALL_ARGS_0() \
78 register unsigned long r2 asm("2")
79 #define CALL_ARGS_1(arg1) \
80 register unsigned long r2 asm("2") = (unsigned long)(arg1)
81 #define CALL_ARGS_2(arg1, arg2) \
82 CALL_ARGS_1(arg1); \
83 register unsigned long r3 asm("3") = (unsigned long)(arg2)
84 #define CALL_ARGS_3(arg1, arg2, arg3) \
85 CALL_ARGS_2(arg1, arg2); \
86 register unsigned long r4 asm("4") = (unsigned long)(arg3)
87 #define CALL_ARGS_4(arg1, arg2, arg3, arg4) \
88 CALL_ARGS_3(arg1, arg2, arg3); \
89 register unsigned long r4 asm("5") = (unsigned long)(arg4)
90 #define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5) \
91 CALL_ARGS_4(arg1, arg2, arg3, arg4); \
92 register unsigned long r4 asm("6") = (unsigned long)(arg5)
93
94 #define CALL_FMT_0 "=&d" (r2) :
95 #define CALL_FMT_1 "+&d" (r2) :
96 #define CALL_FMT_2 CALL_FMT_1 "d" (r3),
97 #define CALL_FMT_3 CALL_FMT_2 "d" (r4),
98 #define CALL_FMT_4 CALL_FMT_3 "d" (r5),
99 #define CALL_FMT_5 CALL_FMT_4 "d" (r6),
100
101 #define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
102 #define CALL_CLOBBER_4 CALL_CLOBBER_5
103 #define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
104 #define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
105 #define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
106 #define CALL_CLOBBER_0 CALL_CLOBBER_1
107
108 #define CALL_ON_STACK(fn, stack, nr, args...) \
109 ({ \
110 unsigned long frame = current_frame_address(); \
111 CALL_ARGS_##nr(args); \
112 unsigned long prev; \
113 \
114 asm volatile( \
115 " la %[_prev],0(15)\n" \
116 " lg 15,%[_stack]\n" \
117 " stg %[_frame],%[_bc](15)\n" \
118 " brasl 14,%[_fn]\n" \
119 " la 15,0(%[_prev])\n" \
120 : [_prev] "=&a" (prev), CALL_FMT_##nr \
121 [_stack] "R" (stack), \
122 [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
123 [_frame] "d" (frame), \
124 [_fn] "X" (fn) : CALL_CLOBBER_##nr); \
125 r2; \
126 })
127
128 #define CALL_ON_STACK_NORETURN(fn, stack) \
129 ({ \
130 asm volatile( \
131 " la 15,0(%[_stack])\n" \
132 " xc %[_bc](8,15),%[_bc](15)\n" \
133 " brasl 14,%[_fn]\n" \
134 ::[_bc] "i" (offsetof(struct stack_frame, back_chain)), \
135 [_stack] "a" (stack), [_fn] "X" (fn)); \
136 BUG(); \
137 })
138
139 #endif /* _ASM_S390_STACKTRACE_H */
140