Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
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
9enum 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
18struct stack_info {
19 enum stack_type type;
20 unsigned long begin, end;
21};
22
23const char *stack_type_name(enum stack_type type);
24int get_stack_info(unsigned long sp, struct task_struct *task,
25 struct stack_info *info, unsigned long *visit_mask);
26
27static 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
37/*
38 * Stack layout of a C stack frame.
39 * Kernel uses the packed stack layout (-mpacked-stack).
40 */
41struct stack_frame {
42 unsigned long empty1[5];
43 unsigned int empty2[8];
44 unsigned long gprs[10];
45 unsigned long back_chain;
46};
47
48/*
49 * Unlike current_stack_pointer which simply contains the current value of %r15
50 * current_frame_address() returns function stack frame address, which matches
51 * %r15 upon function invocation. It may differ from %r15 later if function
52 * allocates stack for local variables or new stack frame to call other
53 * functions.
54 */
55#define current_frame_address() \
56 ((unsigned long)__builtin_frame_address(0) - \
57 offsetof(struct stack_frame, back_chain))
58
59static __always_inline unsigned long get_stack_pointer(struct task_struct *task,
60 struct pt_regs *regs)
61{
62 if (regs)
63 return (unsigned long)kernel_stack_pointer(regs);
64 if (task == current)
65 return current_frame_address();
66 return (unsigned long)task->thread.ksp;
67}
68
69/*
70 * To keep this simple mark register 2-6 as being changed (volatile)
71 * by the called function, even though register 6 is saved/nonvolatile.
72 */
73#define CALL_FMT_0 "=&d" (r2)
74#define CALL_FMT_1 "+&d" (r2)
75#define CALL_FMT_2 CALL_FMT_1, "+&d" (r3)
76#define CALL_FMT_3 CALL_FMT_2, "+&d" (r4)
77#define CALL_FMT_4 CALL_FMT_3, "+&d" (r5)
78#define CALL_FMT_5 CALL_FMT_4, "+&d" (r6)
79
80#define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory"
81#define CALL_CLOBBER_4 CALL_CLOBBER_5
82#define CALL_CLOBBER_3 CALL_CLOBBER_4, "5"
83#define CALL_CLOBBER_2 CALL_CLOBBER_3, "4"
84#define CALL_CLOBBER_1 CALL_CLOBBER_2, "3"
85#define CALL_CLOBBER_0 CALL_CLOBBER_1
86
87#define CALL_LARGS_0(...) \
88 long dummy = 0
89#define CALL_LARGS_1(t1, a1) \
90 long arg1 = (long)(t1)(a1)
91#define CALL_LARGS_2(t1, a1, t2, a2) \
92 CALL_LARGS_1(t1, a1); \
93 long arg2 = (long)(t2)(a2)
94#define CALL_LARGS_3(t1, a1, t2, a2, t3, a3) \
95 CALL_LARGS_2(t1, a1, t2, a2); \
96 long arg3 = (long)(t3)(a3)
97#define CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4) \
98 CALL_LARGS_3(t1, a1, t2, a2, t3, a3); \
99 long arg4 = (long)(t4)(a4)
100#define CALL_LARGS_5(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5) \
101 CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4); \
102 long arg5 = (long)(t5)(a5)
103
104#define CALL_REGS_0 \
105 register long r2 asm("2") = dummy
106#define CALL_REGS_1 \
107 register long r2 asm("2") = arg1
108#define CALL_REGS_2 \
109 CALL_REGS_1; \
110 register long r3 asm("3") = arg2
111#define CALL_REGS_3 \
112 CALL_REGS_2; \
113 register long r4 asm("4") = arg3
114#define CALL_REGS_4 \
115 CALL_REGS_3; \
116 register long r5 asm("5") = arg4
117#define CALL_REGS_5 \
118 CALL_REGS_4; \
119 register long r6 asm("6") = arg5
120
121#define CALL_TYPECHECK_0(...)
122#define CALL_TYPECHECK_1(t, a, ...) \
123 typecheck(t, a)
124#define CALL_TYPECHECK_2(t, a, ...) \
125 CALL_TYPECHECK_1(__VA_ARGS__); \
126 typecheck(t, a)
127#define CALL_TYPECHECK_3(t, a, ...) \
128 CALL_TYPECHECK_2(__VA_ARGS__); \
129 typecheck(t, a)
130#define CALL_TYPECHECK_4(t, a, ...) \
131 CALL_TYPECHECK_3(__VA_ARGS__); \
132 typecheck(t, a)
133#define CALL_TYPECHECK_5(t, a, ...) \
134 CALL_TYPECHECK_4(__VA_ARGS__); \
135 typecheck(t, a)
136
137#define CALL_PARM_0(...) void
138#define CALL_PARM_1(t, a, ...) t
139#define CALL_PARM_2(t, a, ...) t, CALL_PARM_1(__VA_ARGS__)
140#define CALL_PARM_3(t, a, ...) t, CALL_PARM_2(__VA_ARGS__)
141#define CALL_PARM_4(t, a, ...) t, CALL_PARM_3(__VA_ARGS__)
142#define CALL_PARM_5(t, a, ...) t, CALL_PARM_4(__VA_ARGS__)
143#define CALL_PARM_6(t, a, ...) t, CALL_PARM_5(__VA_ARGS__)
144
145/*
146 * Use call_on_stack() to call a function switching to a specified
147 * stack. Proper sign and zero extension of function arguments is
148 * done. Usage:
149 *
150 * rc = call_on_stack(nr, stack, rettype, fn, t1, a1, t2, a2, ...)
151 *
152 * - nr specifies the number of function arguments of fn.
153 * - stack specifies the stack to be used.
154 * - fn is the function to be called.
155 * - rettype is the return type of fn.
156 * - t1, a1, ... are pairs, where t1 must match the type of the first
157 * argument of fn, t2 the second, etc. a1 is the corresponding
158 * first function argument (not name), etc.
159 */
160#define call_on_stack(nr, stack, rettype, fn, ...) \
161({ \
162 rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = fn; \
163 unsigned long frame = current_frame_address(); \
164 unsigned long __stack = stack; \
165 unsigned long prev; \
166 CALL_LARGS_##nr(__VA_ARGS__); \
167 CALL_REGS_##nr; \
168 \
169 CALL_TYPECHECK_##nr(__VA_ARGS__); \
170 asm volatile( \
171 " lgr %[_prev],15\n" \
172 " lg 15,%[_stack]\n" \
173 " stg %[_frame],%[_bc](15)\n" \
174 " brasl 14,%[_fn]\n" \
175 " lgr 15,%[_prev]\n" \
176 : [_prev] "=&d" (prev), CALL_FMT_##nr \
177 : [_stack] "R" (__stack), \
178 [_bc] "i" (offsetof(struct stack_frame, back_chain)), \
179 [_frame] "d" (frame), \
180 [_fn] "X" (__fn) : CALL_CLOBBER_##nr); \
181 (rettype)r2; \
182})
183
184#define call_on_stack_noreturn(fn, stack) \
185({ \
186 void (*__fn)(void) = fn; \
187 \
188 asm volatile( \
189 " la 15,0(%[_stack])\n" \
190 " xc %[_bc](8,15),%[_bc](15)\n" \
191 " brasl 14,%[_fn]\n" \
192 ::[_bc] "i" (offsetof(struct stack_frame, back_chain)), \
193 [_stack] "a" (stack), [_fn] "X" (__fn)); \
194 BUG(); \
195})
196
197#endif /* _ASM_S390_STACKTRACE_H */