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://bugs.llvm.org/show_bug.cgi?id=41424 */
13 #define ftrace_return_address(n) 0UL
14 #else
15 #define ftrace_return_address(n) __builtin_return_address(n)
16 #endif
17
18 void ftrace_caller(void);
19
20 extern void *ftrace_func;
21
22 struct 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
30 struct module;
31 struct dyn_ftrace;
32
33 bool ftrace_need_init_nop(void);
34 #define ftrace_need_init_nop ftrace_need_init_nop
35
36 int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
37 #define ftrace_init_nop ftrace_init_nop
38
ftrace_call_adjust(unsigned long addr)39 static inline unsigned long ftrace_call_adjust(unsigned long addr)
40 {
41 return addr;
42 }
43
44 struct ftrace_regs {
45 struct pt_regs regs;
46 };
47
arch_ftrace_get_regs(struct ftrace_regs * fregs)48 static __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
58 struct fgraph_ret_regs {
59 unsigned long gpr2;
60 unsigned long fp;
61 };
62
fgraph_ret_regs_return_value(struct fgraph_ret_regs * ret_regs)63 static __always_inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
64 {
65 return ret_regs->gpr2;
66 }
67
fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs * ret_regs)68 static __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
74 static __always_inline unsigned long
ftrace_regs_get_instruction_pointer(const struct ftrace_regs * fregs)75 ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs)
76 {
77 return fregs->regs.psw.addr;
78 }
79
80 static __always_inline void
ftrace_regs_set_instruction_pointer(struct ftrace_regs * fregs,unsigned long ip)81 ftrace_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 */
arch_ftrace_set_direct_caller(struct ftrace_regs * fregs,unsigned long addr)108 static 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
arch_trace_is_compat_syscall(struct pt_regs * regs)123 static 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
arch_syscall_match_sym_name(const char * sym,const char * name)129 static 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