1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_S390_FTRACE_H
3 #define _ASM_S390_FTRACE_H
4
5 #define ARCH_SUPPORTS_FTRACE_OPS 1
6 #define MCOUNT_INSN_SIZE 6
7
8 #ifndef __ASSEMBLY__
9 #include <asm/stacktrace.h>
10
11 static __always_inline unsigned long return_address(unsigned int n)
12 {
13 struct stack_frame *sf;
14
15 if (!n)
16 return (unsigned long)__builtin_return_address(0);
17
18 sf = (struct stack_frame *)current_frame_address();
19 do {
20 sf = (struct stack_frame *)sf->back_chain;
21 if (!sf)
22 return 0;
23 } while (--n);
24 return sf->gprs[8];
25 }
26 #define ftrace_return_address(n) return_address(n)
27
28 void ftrace_caller(void);
29
30 extern void *ftrace_func;
31
32 struct dyn_arch_ftrace { };
33
34 #define MCOUNT_ADDR 0
35 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
36
37 #define KPROBE_ON_FTRACE_NOP 0
38 #define KPROBE_ON_FTRACE_CALL 1
39
40 struct module;
41 struct dyn_ftrace;
42
43 bool ftrace_need_init_nop(void);
44 #define ftrace_need_init_nop ftrace_need_init_nop
45
46 int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
47 #define ftrace_init_nop ftrace_init_nop
48
49 static inline unsigned long ftrace_call_adjust(unsigned long addr)
50 {
51 return addr;
52 }
53
54 struct ftrace_regs {
55 struct pt_regs regs;
56 };
57
58 static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)
59 {
60 struct pt_regs *regs = &fregs->regs;
61
62 if (test_pt_regs_flag(regs, PIF_FTRACE_FULL_REGS))
63 return regs;
64 return NULL;
65 }
66
67 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
68 struct fgraph_ret_regs {
69 unsigned long gpr2;
70 unsigned long fp;
71 };
72
73 static __always_inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
74 {
75 return ret_regs->gpr2;
76 }
77
78 static __always_inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
79 {
80 return ret_regs->fp;
81 }
82 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
83
84 static __always_inline unsigned long
85 ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs)
86 {
87 return fregs->regs.psw.addr;
88 }
89
90 static __always_inline void
91 ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
92 unsigned long ip)
93 {
94 fregs->regs.psw.addr = ip;
95 }
96
97 #define ftrace_regs_get_argument(fregs, n) \
98 regs_get_kernel_argument(&(fregs)->regs, n)
99 #define ftrace_regs_get_stack_pointer(fregs) \
100 kernel_stack_pointer(&(fregs)->regs)
101 #define ftrace_regs_return_value(fregs) \
102 regs_return_value(&(fregs)->regs)
103 #define ftrace_regs_set_return_value(fregs, ret) \
104 regs_set_return_value(&(fregs)->regs, ret)
105 #define ftrace_override_function_with_return(fregs) \
106 override_function_with_return(&(fregs)->regs)
107 #define ftrace_regs_query_register_offset(name) \
108 regs_query_register_offset(name)
109
110 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
111 /*
112 * When an ftrace registered caller is tracing a function that is
113 * also set by a register_ftrace_direct() call, it needs to be
114 * differentiated in the ftrace_caller trampoline. To do this,
115 * place the direct caller in the ORIG_GPR2 part of pt_regs. This
116 * tells the ftrace_caller that there's a direct caller.
117 */
118 static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsigned long addr)
119 {
120 struct pt_regs *regs = &fregs->regs;
121 regs->orig_gpr2 = addr;
122 }
123 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
124
125 /*
126 * Even though the system call numbers are identical for s390/s390x a
127 * different system call table is used for compat tasks. This may lead
128 * to e.g. incorrect or missing trace event sysfs files.
129 * Therefore simply do not trace compat system calls at all.
130 * See kernel/trace/trace_syscalls.c.
131 */
132 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
133 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
134 {
135 return is_compat_task();
136 }
137
138 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
139 static inline bool arch_syscall_match_sym_name(const char *sym,
140 const char *name)
141 {
142 /*
143 * Skip __s390_ and __s390x_ prefix - due to compat wrappers
144 * and aliasing some symbols of 64 bit system call functions
145 * may get the __s390_ prefix instead of the __s390x_ prefix.
146 */
147 return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
148 }
149
150 #endif /* __ASSEMBLY__ */
151
152 #ifdef CONFIG_FUNCTION_TRACER
153
154 #define FTRACE_NOP_INSN .word 0xc004, 0x0000, 0x0000 /* brcl 0,0 */
155
156 #ifndef CC_USING_HOTPATCH
157
158 #define FTRACE_GEN_MCOUNT_RECORD(name) \
159 .section __mcount_loc, "a", @progbits; \
160 .quad name; \
161 .previous;
162
163 #else /* !CC_USING_HOTPATCH */
164
165 #define FTRACE_GEN_MCOUNT_RECORD(name)
166
167 #endif /* !CC_USING_HOTPATCH */
168
169 #define FTRACE_GEN_NOP_ASM(name) \
170 FTRACE_GEN_MCOUNT_RECORD(name) \
171 FTRACE_NOP_INSN
172
173 #else /* CONFIG_FUNCTION_TRACER */
174
175 #define FTRACE_GEN_NOP_ASM(name)
176
177 #endif /* CONFIG_FUNCTION_TRACER */
178
179 #endif /* _ASM_S390_FTRACE_H */
180
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