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
on_stack(struct stack_info * info,unsigned long addr,size_t len)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
get_stack_pointer(struct task_struct * task,struct pt_regs * regs)36 static __always_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 == 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 /*
66 * Unlike current_stack_pointer() which simply returns current value of %r15
67 * current_frame_address() returns function stack frame address, which matches
68 * %r15 upon function invocation. It may differ from %r15 later if function
69 * allocates stack for local variables or new stack frame to call other
70 * functions.
71 */
72 #define current_frame_address() \
73 ((unsigned long)__builtin_frame_address(0) - \
74 offsetof(struct stack_frame, back_chain))
75
76 #define CALL_ARGS_0() \
77 register unsigned long r2 asm("2")
78 #define CALL_ARGS_1(arg1) \
79 register unsigned long r2 asm("2") = (unsigned long)(arg1)
80 #define CALL_ARGS_2(arg1, arg2) \
81 CALL_ARGS_1(arg1); \
82 register unsigned long r3 asm("3") = (unsigned long)(arg2)
83 #define CALL_ARGS_3(arg1, arg2, arg3) \
84 CALL_ARGS_2(arg1, arg2); \
85 register unsigned long r4 asm("4") = (unsigned long)(arg3)
86 #define CALL_ARGS_4(arg1, arg2, arg3, arg4) \
87 CALL_ARGS_3(arg1, arg2, arg3); \
88 register unsigned long r4 asm("5") = (unsigned long)(arg4)
89 #define CALL_ARGS_5(arg1, arg2, arg3, arg4, arg5) \
90 CALL_ARGS_4(arg1, arg2, arg3, arg4); \
91 register unsigned long r4 asm("6") = (unsigned long)(arg5)
92
93 /*
94 * To keep this simple mark register 2-6 as being changed (volatile)
95 * by the called function, even though register 6 is saved/nonvolatile.
96 */
97 #define CALL_FMT_0 "=&d" (r2)
98 #define CALL_FMT_1 "+&d" (r2)
99 #define CALL_FMT_2 CALL_FMT_1, "+&d" (r3)
100 #define CALL_FMT_3 CALL_FMT_2, "+&d" (r4)
101 #define CALL_FMT_4 CALL_FMT_3, "+&d" (r5)
102 #define CALL_FMT_5 CALL_FMT_4, "+&d" (r6)
103
104 #define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
105 #define CALL_CLOBBER_4 CALL_CLOBBER_5
106 #define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
107 #define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
108 #define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
109 #define CALL_CLOBBER_0 CALL_CLOBBER_1
110
111 #define CALL_ON_STACK(fn, stack, nr, args...) \
112 ({ \
113 unsigned long frame = current_frame_address(); \
114 CALL_ARGS_##nr(args); \
115 unsigned long prev; \
116 \
117 asm volatile( \
118 " la %[_prev],0(15)\n" \
119 " lg 15,%[_stack]\n" \
120 " stg %[_frame],%[_bc](15)\n" \
121 " brasl 14,%[_fn]\n" \
122 " la 15,0(%[_prev])\n" \
123 : [_prev] "=&a" (prev), CALL_FMT_##nr \
124 : [_stack] "R" (stack), \
125 [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
126 [_frame] "d" (frame), \
127 [_fn] "X" (fn) : CALL_CLOBBER_##nr); \
128 r2; \
129 })
130
131 #define CALL_LARGS_0(...) \
132 long dummy = 0
133 #define CALL_LARGS_1(t1, a1) \
134 long arg1 = (long)(t1)(a1)
135 #define CALL_LARGS_2(t1, a1, t2, a2) \
136 CALL_LARGS_1(t1, a1); \
137 long arg2 = (long)(t2)(a2)
138 #define CALL_LARGS_3(t1, a1, t2, a2, t3, a3) \
139 CALL_LARGS_2(t1, a1, t2, a2); \
140 long arg3 = (long)(t3)(a3)
141 #define CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4) \
142 CALL_LARGS_3(t1, a1, t2, a2, t3, a3); \
143 long arg4 = (long)(t4)(a4)
144 #define CALL_LARGS_5(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5) \
145 CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4); \
146 long arg5 = (long)(t5)(a5)
147
148 #define CALL_REGS_0 \
149 register long r2 asm("2") = dummy
150 #define CALL_REGS_1 \
151 register long r2 asm("2") = arg1
152 #define CALL_REGS_2 \
153 CALL_REGS_1; \
154 register long r3 asm("3") = arg2
155 #define CALL_REGS_3 \
156 CALL_REGS_2; \
157 register long r4 asm("4") = arg3
158 #define CALL_REGS_4 \
159 CALL_REGS_3; \
160 register long r5 asm("5") = arg4
161 #define CALL_REGS_5 \
162 CALL_REGS_4; \
163 register long r6 asm("6") = arg5
164
165 #define CALL_TYPECHECK_0(...)
166 #define CALL_TYPECHECK_1(t, a, ...) \
167 typecheck(t, a)
168 #define CALL_TYPECHECK_2(t, a, ...) \
169 CALL_TYPECHECK_1(__VA_ARGS__); \
170 typecheck(t, a)
171 #define CALL_TYPECHECK_3(t, a, ...) \
172 CALL_TYPECHECK_2(__VA_ARGS__); \
173 typecheck(t, a)
174 #define CALL_TYPECHECK_4(t, a, ...) \
175 CALL_TYPECHECK_3(__VA_ARGS__); \
176 typecheck(t, a)
177 #define CALL_TYPECHECK_5(t, a, ...) \
178 CALL_TYPECHECK_4(__VA_ARGS__); \
179 typecheck(t, a)
180
181 #define CALL_PARM_0(...) void
182 #define CALL_PARM_1(t, a, ...) t
183 #define CALL_PARM_2(t, a, ...) t, CALL_PARM_1(__VA_ARGS__)
184 #define CALL_PARM_3(t, a, ...) t, CALL_PARM_2(__VA_ARGS__)
185 #define CALL_PARM_4(t, a, ...) t, CALL_PARM_3(__VA_ARGS__)
186 #define CALL_PARM_5(t, a, ...) t, CALL_PARM_4(__VA_ARGS__)
187 #define CALL_PARM_6(t, a, ...) t, CALL_PARM_5(__VA_ARGS__)
188
189 /*
190 * Use call_on_stack() to call a function switching to a specified
191 * stack. Proper sign and zero extension of function arguments is
192 * done. Usage:
193 *
194 * rc = call_on_stack(nr, stack, rettype, fn, t1, a1, t2, a2, ...)
195 *
196 * - nr specifies the number of function arguments of fn.
197 * - stack specifies the stack to be used.
198 * - fn is the function to be called.
199 * - rettype is the return type of fn.
200 * - t1, a1, ... are pairs, where t1 must match the type of the first
201 * argument of fn, t2 the second, etc. a1 is the corresponding
202 * first function argument (not name), etc.
203 */
204 #define call_on_stack(nr, stack, rettype, fn, ...) \
205 ({ \
206 rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = fn; \
207 unsigned long frame = current_frame_address(); \
208 unsigned long __stack = stack; \
209 unsigned long prev; \
210 CALL_LARGS_##nr(__VA_ARGS__); \
211 CALL_REGS_##nr; \
212 \
213 CALL_TYPECHECK_##nr(__VA_ARGS__); \
214 asm volatile( \
215 " lgr %[_prev],15\n" \
216 " lg 15,%[_stack]\n" \
217 " stg %[_frame],%[_bc](15)\n" \
218 " brasl 14,%[_fn]\n" \
219 " lgr 15,%[_prev]\n" \
220 : [_prev] "=&d" (prev), CALL_FMT_##nr \
221 : [_stack] "R" (__stack), \
222 [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
223 [_frame] "d" (frame), \
224 [_fn] "X" (__fn) : CALL_CLOBBER_##nr); \
225 (rettype)r2; \
226 })
227
228 #define CALL_ON_STACK_NORETURN(fn, stack) \
229 ({ \
230 asm volatile( \
231 " la 15,0(%[_stack])\n" \
232 " xc %[_bc](8,15),%[_bc](15)\n" \
233 " brasl 14,%[_fn]\n" \
234 ::[_bc] "i" (offsetof(struct stack_frame, back_chain)), \
235 [_stack] "a" (stack), [_fn] "X" (fn)); \
236 BUG(); \
237 })
238
239 #endif /* _ASM_S390_STACKTRACE_H */
240