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 char ftrace_graph_caller_end;
21 extern unsigned long ftrace_plt;
22
23 struct dyn_arch_ftrace { };
24
25 #define MCOUNT_ADDR 0
26 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
27
28 #define KPROBE_ON_FTRACE_NOP 0
29 #define KPROBE_ON_FTRACE_CALL 1
30
31 struct module;
32 struct dyn_ftrace;
33 /*
34 * Either -mhotpatch or -mnop-mcount is used - no explicit init is required
35 */
ftrace_init_nop(struct module * mod,struct dyn_ftrace * rec)36 static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) { return 0; }
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_insn {
45 u16 opc;
46 s32 disp;
47 } __packed;
48
ftrace_generate_nop_insn(struct ftrace_insn * insn)49 static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn)
50 {
51 #ifdef CONFIG_FUNCTION_TRACER
52 /* brcl 0,0 */
53 insn->opc = 0xc004;
54 insn->disp = 0;
55 #endif
56 }
57
is_ftrace_nop(struct ftrace_insn * insn)58 static inline int is_ftrace_nop(struct ftrace_insn *insn)
59 {
60 #ifdef CONFIG_FUNCTION_TRACER
61 if (insn->disp == 0)
62 return 1;
63 #endif
64 return 0;
65 }
66
ftrace_generate_call_insn(struct ftrace_insn * insn,unsigned long ip)67 static inline void ftrace_generate_call_insn(struct ftrace_insn *insn,
68 unsigned long ip)
69 {
70 #ifdef CONFIG_FUNCTION_TRACER
71 unsigned long target;
72
73 /* brasl r0,ftrace_caller */
74 target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR;
75 insn->opc = 0xc005;
76 insn->disp = (target - ip) / 2;
77 #endif
78 }
79
80 /*
81 * Even though the system call numbers are identical for s390/s390x a
82 * different system call table is used for compat tasks. This may lead
83 * to e.g. incorrect or missing trace event sysfs files.
84 * Therefore simply do not trace compat system calls at all.
85 * See kernel/trace/trace_syscalls.c.
86 */
87 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
arch_trace_is_compat_syscall(struct pt_regs * regs)88 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
89 {
90 return is_compat_task();
91 }
92
93 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
arch_syscall_match_sym_name(const char * sym,const char * name)94 static inline bool arch_syscall_match_sym_name(const char *sym,
95 const char *name)
96 {
97 /*
98 * Skip __s390_ and __s390x_ prefix - due to compat wrappers
99 * and aliasing some symbols of 64 bit system call functions
100 * may get the __s390_ prefix instead of the __s390x_ prefix.
101 */
102 return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
103 }
104
105 #endif /* __ASSEMBLY__ */
106 #endif /* _ASM_S390_FTRACE_H */
107