xref: /linux/arch/s390/include/asm/ftrace.h (revision b8a1c9f4b7106c94d95c83416d34277ee689638f)
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 
return_address(unsigned int n)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 struct ftrace_ops;
43 
44 bool ftrace_need_init_nop(void);
45 #define ftrace_need_init_nop ftrace_need_init_nop
46 
47 int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
48 #define ftrace_init_nop ftrace_init_nop
49 
ftrace_call_adjust(unsigned long addr)50 static inline unsigned long ftrace_call_adjust(unsigned long addr)
51 {
52 	return addr;
53 }
54 #define ftrace_get_symaddr(fentry_ip) ((unsigned long)(fentry_ip))
55 
56 #include <linux/ftrace_regs.h>
57 
arch_ftrace_get_regs(struct ftrace_regs * fregs)58 static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)
59 {
60 	struct pt_regs *regs = &arch_ftrace_regs(fregs)->regs;
61 
62 	if (test_pt_regs_flag(regs, PIF_FTRACE_FULL_REGS))
63 		return regs;
64 	return NULL;
65 }
66 
67 static __always_inline void
ftrace_regs_set_instruction_pointer(struct ftrace_regs * fregs,unsigned long ip)68 ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
69 				    unsigned long ip)
70 {
71 	arch_ftrace_regs(fregs)->regs.psw.addr = ip;
72 }
73 
74 #undef ftrace_regs_get_frame_pointer
75 static __always_inline unsigned long
ftrace_regs_get_frame_pointer(struct ftrace_regs * fregs)76 ftrace_regs_get_frame_pointer(struct ftrace_regs *fregs)
77 {
78 	return ftrace_regs_get_stack_pointer(fregs);
79 }
80 
81 static __always_inline unsigned long
ftrace_regs_get_return_address(const struct ftrace_regs * fregs)82 ftrace_regs_get_return_address(const struct ftrace_regs *fregs)
83 {
84 	return arch_ftrace_regs(fregs)->regs.gprs[14];
85 }
86 
87 #define arch_ftrace_fill_perf_regs(fregs, _regs)	 do {		\
88 		(_regs)->psw.mask = 0;					\
89 		(_regs)->psw.addr = arch_ftrace_regs(fregs)->regs.psw.addr;		\
90 		(_regs)->gprs[15] = arch_ftrace_regs(fregs)->regs.gprs[15];		\
91 	} while (0)
92 
93 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
94 /*
95  * When an ftrace registered caller is tracing a function that is
96  * also set by a register_ftrace_direct() call, it needs to be
97  * differentiated in the ftrace_caller trampoline. To do this,
98  * place the direct caller in the ORIG_GPR2 part of pt_regs. This
99  * tells the ftrace_caller that there's a direct caller.
100  */
arch_ftrace_set_direct_caller(struct ftrace_regs * fregs,unsigned long addr)101 static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsigned long addr)
102 {
103 	struct pt_regs *regs = &arch_ftrace_regs(fregs)->regs;
104 	regs->orig_gpr2 = addr;
105 }
106 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
107 
108 /*
109  * Even though the system call numbers are identical for s390/s390x a
110  * different system call table is used for compat tasks. This may lead
111  * to e.g. incorrect or missing trace event sysfs files.
112  * Therefore simply do not trace compat system calls at all.
113  * See kernel/trace/trace_syscalls.c.
114  */
115 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
arch_trace_is_compat_syscall(struct pt_regs * regs)116 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
117 {
118 	return is_compat_task();
119 }
120 
121 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
arch_syscall_match_sym_name(const char * sym,const char * name)122 static inline bool arch_syscall_match_sym_name(const char *sym,
123 					       const char *name)
124 {
125 	/*
126 	 * Skip __s390_ and __s390x_ prefix - due to compat wrappers
127 	 * and aliasing some symbols of 64 bit system call functions
128 	 * may get the __s390_ prefix instead of the __s390x_ prefix.
129 	 */
130 	return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
131 }
132 
133 void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
134 		       struct ftrace_ops *op, struct ftrace_regs *fregs);
135 #define ftrace_graph_func ftrace_graph_func
136 
137 #endif /* __ASSEMBLY__ */
138 
139 #ifdef CONFIG_FUNCTION_TRACER
140 
141 #define FTRACE_NOP_INSN .word 0xc004, 0x0000, 0x0000 /* brcl 0,0 */
142 
143 #ifndef CC_USING_HOTPATCH
144 
145 #define FTRACE_GEN_MCOUNT_RECORD(name)		\
146 	.section __mcount_loc, "a", @progbits;	\
147 	.quad name;				\
148 	.previous;
149 
150 #else /* !CC_USING_HOTPATCH */
151 
152 #define FTRACE_GEN_MCOUNT_RECORD(name)
153 
154 #endif /* !CC_USING_HOTPATCH */
155 
156 #define FTRACE_GEN_NOP_ASM(name)		\
157 	FTRACE_GEN_MCOUNT_RECORD(name)		\
158 	FTRACE_NOP_INSN
159 
160 #else /* CONFIG_FUNCTION_TRACER */
161 
162 #define FTRACE_GEN_NOP_ASM(name)
163 
164 #endif /* CONFIG_FUNCTION_TRACER */
165 
166 #endif /* _ASM_S390_FTRACE_H */
167