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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 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
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
57static __always_inline unsigned long
58ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs)
59{
60 return fregs->regs.psw.addr;
61}
62
63static __always_inline void
64ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
65 unsigned long ip)
66{
67 fregs->regs.psw.addr = ip;
68}
69
70#define ftrace_regs_get_argument(fregs, n) \
71 regs_get_kernel_argument(&(fregs)->regs, n)
72#define ftrace_regs_get_stack_pointer(fregs) \
73 kernel_stack_pointer(&(fregs)->regs)
74#define ftrace_regs_return_value(fregs) \
75 regs_return_value(&(fregs)->regs)
76#define ftrace_regs_set_return_value(fregs, ret) \
77 regs_set_return_value(&(fregs)->regs, ret)
78#define ftrace_override_function_with_return(fregs) \
79 override_function_with_return(&(fregs)->regs)
80#define ftrace_regs_query_register_offset(name) \
81 regs_query_register_offset(name)
82
83#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
84/*
85 * When an ftrace registered caller is tracing a function that is
86 * also set by a register_ftrace_direct() call, it needs to be
87 * differentiated in the ftrace_caller trampoline. To do this,
88 * place the direct caller in the ORIG_GPR2 part of pt_regs. This
89 * tells the ftrace_caller that there's a direct caller.
90 */
91static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsigned long addr)
92{
93 struct pt_regs *regs = &fregs->regs;
94 regs->orig_gpr2 = addr;
95}
96#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
97
98/*
99 * Even though the system call numbers are identical for s390/s390x a
100 * different system call table is used for compat tasks. This may lead
101 * to e.g. incorrect or missing trace event sysfs files.
102 * Therefore simply do not trace compat system calls at all.
103 * See kernel/trace/trace_syscalls.c.
104 */
105#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
106static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
107{
108 return is_compat_task();
109}
110
111#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
112static inline bool arch_syscall_match_sym_name(const char *sym,
113 const char *name)
114{
115 /*
116 * Skip __s390_ and __s390x_ prefix - due to compat wrappers
117 * and aliasing some symbols of 64 bit system call functions
118 * may get the __s390_ prefix instead of the __s390x_ prefix.
119 */
120 return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
121}
122
123#endif /* __ASSEMBLY__ */
124
125#ifdef CONFIG_FUNCTION_TRACER
126
127#define FTRACE_NOP_INSN .word 0xc004, 0x0000, 0x0000 /* brcl 0,0 */
128
129#ifndef CC_USING_HOTPATCH
130
131#define FTRACE_GEN_MCOUNT_RECORD(name) \
132 .section __mcount_loc, "a", @progbits; \
133 .quad name; \
134 .previous;
135
136#else /* !CC_USING_HOTPATCH */
137
138#define FTRACE_GEN_MCOUNT_RECORD(name)
139
140#endif /* !CC_USING_HOTPATCH */
141
142#define FTRACE_GEN_NOP_ASM(name) \
143 FTRACE_GEN_MCOUNT_RECORD(name) \
144 FTRACE_NOP_INSN
145
146#else /* CONFIG_FUNCTION_TRACER */
147
148#define FTRACE_GEN_NOP_ASM(name)
149
150#endif /* CONFIG_FUNCTION_TRACER */
151
152#endif /* _ASM_S390_FTRACE_H */
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#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
15
16#ifndef __ASSEMBLY__
17
18#ifdef CONFIG_CC_IS_CLANG
19/* https://bugs.llvm.org/show_bug.cgi?id=41424 */
20#define ftrace_return_address(n) 0UL
21#else
22#define ftrace_return_address(n) __builtin_return_address(n)
23#endif
24
25void _mcount(void);
26void ftrace_caller(void);
27
28extern char ftrace_graph_caller_end;
29extern unsigned long ftrace_plt;
30
31struct dyn_arch_ftrace { };
32
33#define MCOUNT_ADDR ((unsigned long)_mcount)
34#define FTRACE_ADDR ((unsigned long)ftrace_caller)
35
36#define KPROBE_ON_FTRACE_NOP 0
37#define KPROBE_ON_FTRACE_CALL 1
38
39static inline unsigned long ftrace_call_adjust(unsigned long addr)
40{
41 return addr;
42}
43
44struct ftrace_insn {
45 u16 opc;
46 s32 disp;
47} __packed;
48
49static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn)
50{
51#ifdef CONFIG_FUNCTION_TRACER
52#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
53 /* brcl 0,0 */
54 insn->opc = 0xc004;
55 insn->disp = 0;
56#else
57 /* jg .+24 */
58 insn->opc = 0xc0f4;
59 insn->disp = MCOUNT_INSN_SIZE / 2;
60#endif
61#endif
62}
63
64static inline int is_ftrace_nop(struct ftrace_insn *insn)
65{
66#ifdef CONFIG_FUNCTION_TRACER
67#if defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT)
68 if (insn->disp == 0)
69 return 1;
70#else
71 if (insn->disp == MCOUNT_INSN_SIZE / 2)
72 return 1;
73#endif
74#endif
75 return 0;
76}
77
78static inline void ftrace_generate_call_insn(struct ftrace_insn *insn,
79 unsigned long ip)
80{
81#ifdef CONFIG_FUNCTION_TRACER
82 unsigned long target;
83
84 /* brasl r0,ftrace_caller */
85 target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR;
86 insn->opc = 0xc005;
87 insn->disp = (target - ip) / 2;
88#endif
89}
90
91/*
92 * Even though the system call numbers are identical for s390/s390x a
93 * different system call table is used for compat tasks. This may lead
94 * to e.g. incorrect or missing trace event sysfs files.
95 * Therefore simply do not trace compat system calls at all.
96 * See kernel/trace/trace_syscalls.c.
97 */
98#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
99static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
100{
101 return is_compat_task();
102}
103
104#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
105static inline bool arch_syscall_match_sym_name(const char *sym,
106 const char *name)
107{
108 /*
109 * Skip __s390_ and __s390x_ prefix - due to compat wrappers
110 * and aliasing some symbols of 64 bit system call functions
111 * may get the __s390_ prefix instead of the __s390x_ prefix.
112 */
113 return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
114}
115
116#endif /* __ASSEMBLY__ */
117#endif /* _ASM_S390_FTRACE_H */