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 struct stack_frame_user {
10 unsigned long back_chain;
11 unsigned long empty1[5];
12 unsigned long gprs[10];
13 unsigned long empty2[4];
14 };
15
16 enum stack_type {
17 STACK_TYPE_UNKNOWN,
18 STACK_TYPE_TASK,
19 STACK_TYPE_IRQ,
20 STACK_TYPE_NODAT,
21 STACK_TYPE_RESTART,
22 STACK_TYPE_MCCK,
23 };
24
25 struct stack_info {
26 enum stack_type type;
27 unsigned long begin, end;
28 };
29
30 const char *stack_type_name(enum stack_type type);
31 int get_stack_info(unsigned long sp, struct task_struct *task,
32 struct stack_info *info, unsigned long *visit_mask);
33
on_stack(struct stack_info * info,unsigned long addr,size_t len)34 static inline bool on_stack(struct stack_info *info,
35 unsigned long addr, size_t len)
36 {
37 if (info->type == STACK_TYPE_UNKNOWN)
38 return false;
39 if (addr + len < addr)
40 return false;
41 return addr >= info->begin && addr + len <= info->end;
42 }
43
44 /*
45 * Stack layout of a C stack frame.
46 * Kernel uses the packed stack layout (-mpacked-stack).
47 */
48 struct stack_frame {
49 union {
50 unsigned long empty[9];
51 struct {
52 unsigned long sie_control_block;
53 unsigned long sie_savearea;
54 unsigned long sie_reason;
55 unsigned long sie_flags;
56 unsigned long sie_control_block_phys;
57 };
58 };
59 unsigned long gprs[10];
60 unsigned long back_chain;
61 };
62
63 /*
64 * Unlike current_stack_pointer which simply contains the current value of %r15
65 * current_frame_address() returns function stack frame address, which matches
66 * %r15 upon function invocation. It may differ from %r15 later if function
67 * allocates stack for local variables or new stack frame to call other
68 * functions.
69 */
70 #define current_frame_address() \
71 ((unsigned long)__builtin_frame_address(0) - \
72 offsetof(struct stack_frame, back_chain))
73
get_stack_pointer(struct task_struct * task,struct pt_regs * regs)74 static __always_inline unsigned long get_stack_pointer(struct task_struct *task,
75 struct pt_regs *regs)
76 {
77 if (regs)
78 return (unsigned long)kernel_stack_pointer(regs);
79 if (task == current)
80 return current_frame_address();
81 return (unsigned long)task->thread.ksp;
82 }
83
84 /*
85 * To keep this simple mark register 2-6 as being changed (volatile)
86 * by the called function, even though register 6 is saved/nonvolatile.
87 */
88 #define CALL_FMT_0 "=&d" (r2)
89 #define CALL_FMT_1 "+&d" (r2)
90 #define CALL_FMT_2 CALL_FMT_1, "+&d" (r3)
91 #define CALL_FMT_3 CALL_FMT_2, "+&d" (r4)
92 #define CALL_FMT_4 CALL_FMT_3, "+&d" (r5)
93 #define CALL_FMT_5 CALL_FMT_4, "+&d" (r6)
94
95 #define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
96 #define CALL_CLOBBER_4 CALL_CLOBBER_5
97 #define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
98 #define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
99 #define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
100 #define CALL_CLOBBER_0 CALL_CLOBBER_1
101
102 #define CALL_LARGS_0(...) \
103 long dummy = 0
104 #define CALL_LARGS_1(t1, a1) \
105 long arg1 = (long)(t1)(a1)
106 #define CALL_LARGS_2(t1, a1, t2, a2) \
107 CALL_LARGS_1(t1, a1); \
108 long arg2 = (long)(t2)(a2)
109 #define CALL_LARGS_3(t1, a1, t2, a2, t3, a3) \
110 CALL_LARGS_2(t1, a1, t2, a2); \
111 long arg3 = (long)(t3)(a3)
112 #define CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4) \
113 CALL_LARGS_3(t1, a1, t2, a2, t3, a3); \
114 long arg4 = (long)(t4)(a4)
115 #define CALL_LARGS_5(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5) \
116 CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4); \
117 long arg5 = (long)(t5)(a5)
118
119 #define CALL_REGS_0 \
120 register long r2 asm("2") = dummy
121 #define CALL_REGS_1 \
122 register long r2 asm("2") = arg1
123 #define CALL_REGS_2 \
124 CALL_REGS_1; \
125 register long r3 asm("3") = arg2
126 #define CALL_REGS_3 \
127 CALL_REGS_2; \
128 register long r4 asm("4") = arg3
129 #define CALL_REGS_4 \
130 CALL_REGS_3; \
131 register long r5 asm("5") = arg4
132 #define CALL_REGS_5 \
133 CALL_REGS_4; \
134 register long r6 asm("6") = arg5
135
136 #define CALL_TYPECHECK_0(...)
137 #define CALL_TYPECHECK_1(t, a, ...) \
138 typecheck(t, a)
139 #define CALL_TYPECHECK_2(t, a, ...) \
140 CALL_TYPECHECK_1(__VA_ARGS__); \
141 typecheck(t, a)
142 #define CALL_TYPECHECK_3(t, a, ...) \
143 CALL_TYPECHECK_2(__VA_ARGS__); \
144 typecheck(t, a)
145 #define CALL_TYPECHECK_4(t, a, ...) \
146 CALL_TYPECHECK_3(__VA_ARGS__); \
147 typecheck(t, a)
148 #define CALL_TYPECHECK_5(t, a, ...) \
149 CALL_TYPECHECK_4(__VA_ARGS__); \
150 typecheck(t, a)
151
152 #define CALL_PARM_0(...) void
153 #define CALL_PARM_1(t, a, ...) t
154 #define CALL_PARM_2(t, a, ...) t, CALL_PARM_1(__VA_ARGS__)
155 #define CALL_PARM_3(t, a, ...) t, CALL_PARM_2(__VA_ARGS__)
156 #define CALL_PARM_4(t, a, ...) t, CALL_PARM_3(__VA_ARGS__)
157 #define CALL_PARM_5(t, a, ...) t, CALL_PARM_4(__VA_ARGS__)
158 #define CALL_PARM_6(t, a, ...) t, CALL_PARM_5(__VA_ARGS__)
159
160 /*
161 * Use call_on_stack() to call a function switching to a specified
162 * stack. Proper sign and zero extension of function arguments is
163 * done. Usage:
164 *
165 * rc = call_on_stack(nr, stack, rettype, fn, t1, a1, t2, a2, ...)
166 *
167 * - nr specifies the number of function arguments of fn.
168 * - stack specifies the stack to be used.
169 * - fn is the function to be called.
170 * - rettype is the return type of fn.
171 * - t1, a1, ... are pairs, where t1 must match the type of the first
172 * argument of fn, t2 the second, etc. a1 is the corresponding
173 * first function argument (not name), etc.
174 */
175 #define call_on_stack(nr, stack, rettype, fn, ...) \
176 ({ \
177 rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = fn; \
178 unsigned long frame = current_frame_address(); \
179 unsigned long __stack = stack; \
180 unsigned long prev; \
181 CALL_LARGS_##nr(__VA_ARGS__); \
182 CALL_REGS_##nr; \
183 \
184 CALL_TYPECHECK_##nr(__VA_ARGS__); \
185 asm volatile( \
186 " lgr %[_prev],15\n" \
187 " lg 15,%[_stack]\n" \
188 " stg %[_frame],%[_bc](15)\n" \
189 " brasl 14,%[_fn]\n" \
190 " lgr 15,%[_prev]\n" \
191 : [_prev] "=&d" (prev), CALL_FMT_##nr \
192 : [_stack] "R" (__stack), \
193 [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
194 [_frame] "d" (frame), \
195 [_fn] "X" (__fn) : CALL_CLOBBER_##nr); \
196 (rettype)r2; \
197 })
198
199 /*
200 * Use call_nodat() to call a function with DAT disabled.
201 * Proper sign and zero extension of function arguments is done.
202 * Usage:
203 *
204 * rc = call_nodat(nr, rettype, fn, t1, a1, t2, a2, ...)
205 *
206 * - nr specifies the number of function arguments of fn.
207 * - fn is the function to be called, where fn is a physical address.
208 * - rettype is the return type of fn.
209 * - t1, a1, ... are pairs, where t1 must match the type of the first
210 * argument of fn, t2 the second, etc. a1 is the corresponding
211 * first function argument (not name), etc.
212 *
213 * fn() is called with standard C function call ABI, with the exception
214 * that no useful stackframe or stackpointer is passed via register 15.
215 * Therefore the called function must not use r15 to access the stack.
216 */
217 #define call_nodat(nr, rettype, fn, ...) \
218 ({ \
219 rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = (fn); \
220 /* aligned since psw_leave must not cross page boundary */ \
221 psw_t __aligned(16) psw_leave; \
222 psw_t psw_enter; \
223 CALL_LARGS_##nr(__VA_ARGS__); \
224 CALL_REGS_##nr; \
225 \
226 CALL_TYPECHECK_##nr(__VA_ARGS__); \
227 psw_enter.mask = PSW_KERNEL_BITS & ~PSW_MASK_DAT; \
228 psw_enter.addr = (unsigned long)__fn; \
229 asm volatile( \
230 " epsw 0,1\n" \
231 " risbg 1,0,0,31,32\n" \
232 " larl 7,1f\n" \
233 " stg 1,%[psw_leave]\n" \
234 " stg 7,8+%[psw_leave]\n" \
235 " la 7,%[psw_leave]\n" \
236 " lra 7,0(7)\n" \
237 " larl 1,0f\n" \
238 " lra 14,0(1)\n" \
239 " lpswe %[psw_enter]\n" \
240 "0: lpswe 0(7)\n" \
241 "1:\n" \
242 : CALL_FMT_##nr, [psw_leave] "=Q" (psw_leave) \
243 : [psw_enter] "Q" (psw_enter) \
244 : "7", CALL_CLOBBER_##nr); \
245 (rettype)r2; \
246 })
247
248 #endif /* _ASM_S390_STACKTRACE_H */
249