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Linux kernel mirror (for testing)
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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
7#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
8#define MCOUNT_INSN_SIZE 6
9#else
10#define MCOUNT_INSN_SIZE 24
11#define MCOUNT_RETURN_FIXUP 18
12#endif
13
14#ifndef __ASSEMBLY__
15
16#define ftrace_return_address(n) __builtin_return_address(n)
17
18void _mcount(void);
19void ftrace_caller(void);
20
21extern char ftrace_graph_caller_end;
22extern unsigned long ftrace_plt;
23
24struct dyn_arch_ftrace { };
25
26#define MCOUNT_ADDR ((unsigned long)_mcount)
27#define FTRACE_ADDR ((unsigned long)ftrace_caller)
28
29#define KPROBE_ON_FTRACE_NOP 0
30#define KPROBE_ON_FTRACE_CALL 1
31
32static inline unsigned long ftrace_call_adjust(unsigned long addr)
33{
34 return addr;
35}
36
37struct ftrace_insn {
38 u16 opc;
39 s32 disp;
40} __packed;
41
42static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn)
43{
44#ifdef CONFIG_FUNCTION_TRACER
45#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
46 /* brcl 0,0 */
47 insn->opc = 0xc004;
48 insn->disp = 0;
49#else
50 /* jg .+24 */
51 insn->opc = 0xc0f4;
52 insn->disp = MCOUNT_INSN_SIZE / 2;
53#endif
54#endif
55}
56
57static inline int is_ftrace_nop(struct ftrace_insn *insn)
58{
59#ifdef CONFIG_FUNCTION_TRACER
60#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
61 if (insn->disp == 0)
62 return 1;
63#else
64 if (insn->disp == MCOUNT_INSN_SIZE / 2)
65 return 1;
66#endif
67#endif
68 return 0;
69}
70
71static inline void ftrace_generate_call_insn(struct ftrace_insn *insn,
72 unsigned long ip)
73{
74#ifdef CONFIG_FUNCTION_TRACER
75 unsigned long target;
76
77 /* brasl r0,ftrace_caller */
78 target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR;
79 insn->opc = 0xc005;
80 insn->disp = (target - ip) / 2;
81#endif
82}
83
84/*
85 * Even though the system call numbers are identical for s390/s390x a
86 * different system call table is used for compat tasks. This may lead
87 * to e.g. incorrect or missing trace event sysfs files.
88 * Therefore simply do not trace compat system calls at all.
89 * See kernel/trace/trace_syscalls.c.
90 */
91#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
92static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
93{
94 return is_compat_task();
95}
96
97#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
98static inline bool arch_syscall_match_sym_name(const char *sym,
99 const char *name)
100{
101 /*
102 * Skip __s390_ and __s390x_ prefix - due to compat wrappers
103 * and aliasing some symbols of 64 bit system call functions
104 * may get the __s390_ prefix instead of the __s390x_ prefix.
105 */
106 return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
107}
108
109#endif /* __ASSEMBLY__ */
110#endif /* _ASM_S390_FTRACE_H */