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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
11static __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
28void ftrace_caller(void);
29
30extern void *ftrace_func;
31
32struct 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
40struct module;
41struct dyn_ftrace;
42
43bool ftrace_need_init_nop(void);
44#define ftrace_need_init_nop ftrace_need_init_nop
45
46int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
47#define ftrace_init_nop ftrace_init_nop
48
49static inline unsigned long ftrace_call_adjust(unsigned long addr)
50{
51 return addr;
52}
53
54struct ftrace_regs {
55 struct pt_regs regs;
56};
57
58static __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
68struct fgraph_ret_regs {
69 unsigned long gpr2;
70 unsigned long fp;
71};
72
73static __always_inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
74{
75 return ret_regs->gpr2;
76}
77
78static __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
84static __always_inline unsigned long
85ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs)
86{
87 return fregs->regs.psw.addr;
88}
89
90static __always_inline void
91ftrace_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 */
118static 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
133static 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
139static 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 */