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
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
ftrace_call_adjust(unsigned long addr)49 static inline unsigned long ftrace_call_adjust(unsigned long addr)
50 {
51 return addr;
52 }
53
54 #include <linux/ftrace_regs.h>
55
arch_ftrace_get_regs(struct ftrace_regs * fregs)56 static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *fregs)
57 {
58 struct pt_regs *regs = &arch_ftrace_regs(fregs)->regs;
59
60 if (test_pt_regs_flag(regs, PIF_FTRACE_FULL_REGS))
61 return regs;
62 return NULL;
63 }
64
65 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
66 struct fgraph_ret_regs {
67 unsigned long gpr2;
68 unsigned long fp;
69 };
70
fgraph_ret_regs_return_value(struct fgraph_ret_regs * ret_regs)71 static __always_inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
72 {
73 return ret_regs->gpr2;
74 }
75
fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs * ret_regs)76 static __always_inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
77 {
78 return ret_regs->fp;
79 }
80 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
81
82 static __always_inline void
ftrace_regs_set_instruction_pointer(struct ftrace_regs * fregs,unsigned long ip)83 ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
84 unsigned long ip)
85 {
86 arch_ftrace_regs(fregs)->regs.psw.addr = ip;
87 }
88
89 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
90 /*
91 * When an ftrace registered caller is tracing a function that is
92 * also set by a register_ftrace_direct() call, it needs to be
93 * differentiated in the ftrace_caller trampoline. To do this,
94 * place the direct caller in the ORIG_GPR2 part of pt_regs. This
95 * tells the ftrace_caller that there's a direct caller.
96 */
arch_ftrace_set_direct_caller(struct ftrace_regs * fregs,unsigned long addr)97 static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsigned long addr)
98 {
99 struct pt_regs *regs = &arch_ftrace_regs(fregs)->regs;
100 regs->orig_gpr2 = addr;
101 }
102 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
103
104 /*
105 * Even though the system call numbers are identical for s390/s390x a
106 * different system call table is used for compat tasks. This may lead
107 * to e.g. incorrect or missing trace event sysfs files.
108 * Therefore simply do not trace compat system calls at all.
109 * See kernel/trace/trace_syscalls.c.
110 */
111 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
arch_trace_is_compat_syscall(struct pt_regs * regs)112 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
113 {
114 return is_compat_task();
115 }
116
117 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
arch_syscall_match_sym_name(const char * sym,const char * name)118 static inline bool arch_syscall_match_sym_name(const char *sym,
119 const char *name)
120 {
121 /*
122 * Skip __s390_ and __s390x_ prefix - due to compat wrappers
123 * and aliasing some symbols of 64 bit system call functions
124 * may get the __s390_ prefix instead of the __s390x_ prefix.
125 */
126 return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
127 }
128
129 #endif /* __ASSEMBLY__ */
130
131 #ifdef CONFIG_FUNCTION_TRACER
132
133 #define FTRACE_NOP_INSN .word 0xc004, 0x0000, 0x0000 /* brcl 0,0 */
134
135 #ifndef CC_USING_HOTPATCH
136
137 #define FTRACE_GEN_MCOUNT_RECORD(name) \
138 .section __mcount_loc, "a", @progbits; \
139 .quad name; \
140 .previous;
141
142 #else /* !CC_USING_HOTPATCH */
143
144 #define FTRACE_GEN_MCOUNT_RECORD(name)
145
146 #endif /* !CC_USING_HOTPATCH */
147
148 #define FTRACE_GEN_NOP_ASM(name) \
149 FTRACE_GEN_MCOUNT_RECORD(name) \
150 FTRACE_NOP_INSN
151
152 #else /* CONFIG_FUNCTION_TRACER */
153
154 #define FTRACE_GEN_NOP_ASM(name)
155
156 #endif /* CONFIG_FUNCTION_TRACER */
157
158 #endif /* _ASM_S390_FTRACE_H */
159