1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_S390_FTRACE_H
3#define _ASM_S390_FTRACE_H
4
5#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
6#define ARCH_SUPPORTS_FTRACE_OPS 1
7#define MCOUNT_INSN_SIZE	6
8
9#ifndef __ASSEMBLY__
10
11#ifdef CONFIG_CC_IS_CLANG
12/* https://llvm.org/pr41424 */
13#define ftrace_return_address(n) 0UL
14#else
15#define ftrace_return_address(n) __builtin_return_address(n)
16#endif
17
18void ftrace_caller(void);
19
20extern void *ftrace_func;
21
22struct dyn_arch_ftrace { };
23
24#define MCOUNT_ADDR 0
25#define FTRACE_ADDR ((unsigned long)ftrace_caller)
26
27#define KPROBE_ON_FTRACE_NOP	0
28#define KPROBE_ON_FTRACE_CALL	1
29
30struct module;
31struct dyn_ftrace;
32
33bool ftrace_need_init_nop(void);
34#define ftrace_need_init_nop ftrace_need_init_nop
35
36int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
37#define ftrace_init_nop ftrace_init_nop
38
39static inline unsigned long ftrace_call_adjust(unsigned long addr)
40{
41	return addr;
42}
43
44struct ftrace_regs {
45	struct pt_regs regs;
46};
47
48static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)
49{
50	struct pt_regs *regs = &fregs->regs;
51
52	if (test_pt_regs_flag(regs, PIF_FTRACE_FULL_REGS))
53		return regs;
54	return NULL;
55}
56
57#ifdef CONFIG_FUNCTION_GRAPH_TRACER
58struct fgraph_ret_regs {
59	unsigned long gpr2;
60	unsigned long fp;
61};
62
63static __always_inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
64{
65	return ret_regs->gpr2;
66}
67
68static __always_inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
69{
70	return ret_regs->fp;
71}
72#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
73
74static __always_inline unsigned long
75ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs)
76{
77	return fregs->regs.psw.addr;
78}
79
80static __always_inline void
81ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
82				    unsigned long ip)
83{
84	fregs->regs.psw.addr = ip;
85}
86
87#define ftrace_regs_get_argument(fregs, n) \
88	regs_get_kernel_argument(&(fregs)->regs, n)
89#define ftrace_regs_get_stack_pointer(fregs) \
90	kernel_stack_pointer(&(fregs)->regs)
91#define ftrace_regs_return_value(fregs) \
92	regs_return_value(&(fregs)->regs)
93#define ftrace_regs_set_return_value(fregs, ret) \
94	regs_set_return_value(&(fregs)->regs, ret)
95#define ftrace_override_function_with_return(fregs) \
96	override_function_with_return(&(fregs)->regs)
97#define ftrace_regs_query_register_offset(name) \
98	regs_query_register_offset(name)
99
100#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
101/*
102 * When an ftrace registered caller is tracing a function that is
103 * also set by a register_ftrace_direct() call, it needs to be
104 * differentiated in the ftrace_caller trampoline. To do this,
105 * place the direct caller in the ORIG_GPR2 part of pt_regs. This
106 * tells the ftrace_caller that there's a direct caller.
107 */
108static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsigned long addr)
109{
110	struct pt_regs *regs = &fregs->regs;
111	regs->orig_gpr2 = addr;
112}
113#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
114
115/*
116 * Even though the system call numbers are identical for s390/s390x a
117 * different system call table is used for compat tasks. This may lead
118 * to e.g. incorrect or missing trace event sysfs files.
119 * Therefore simply do not trace compat system calls at all.
120 * See kernel/trace/trace_syscalls.c.
121 */
122#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
123static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
124{
125	return is_compat_task();
126}
127
128#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
129static inline bool arch_syscall_match_sym_name(const char *sym,
130					       const char *name)
131{
132	/*
133	 * Skip __s390_ and __s390x_ prefix - due to compat wrappers
134	 * and aliasing some symbols of 64 bit system call functions
135	 * may get the __s390_ prefix instead of the __s390x_ prefix.
136	 */
137	return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
138}
139
140#endif /* __ASSEMBLY__ */
141
142#ifdef CONFIG_FUNCTION_TRACER
143
144#define FTRACE_NOP_INSN .word 0xc004, 0x0000, 0x0000 /* brcl 0,0 */
145
146#ifndef CC_USING_HOTPATCH
147
148#define FTRACE_GEN_MCOUNT_RECORD(name)		\
149	.section __mcount_loc, "a", @progbits;	\
150	.quad name;				\
151	.previous;
152
153#else /* !CC_USING_HOTPATCH */
154
155#define FTRACE_GEN_MCOUNT_RECORD(name)
156
157#endif /* !CC_USING_HOTPATCH */
158
159#define FTRACE_GEN_NOP_ASM(name)		\
160	FTRACE_GEN_MCOUNT_RECORD(name)		\
161	FTRACE_NOP_INSN
162
163#else /* CONFIG_FUNCTION_TRACER */
164
165#define FTRACE_GEN_NOP_ASM(name)
166
167#endif /* CONFIG_FUNCTION_TRACER */
168
169#endif /* _ASM_S390_FTRACE_H */
170