xref: /openbmc/linux/arch/x86/include/asm/ftrace.h (revision 0bf49ffb)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_FTRACE_H
3 #define _ASM_X86_FTRACE_H
4 
5 #ifdef CONFIG_FUNCTION_TRACER
6 #ifndef CC_USING_FENTRY
7 # error Compiler does not support fentry?
8 #endif
9 # define MCOUNT_ADDR		((unsigned long)(__fentry__))
10 #define MCOUNT_INSN_SIZE	5 /* sizeof mcount call */
11 
12 #ifdef CONFIG_DYNAMIC_FTRACE
13 #define ARCH_SUPPORTS_FTRACE_OPS 1
14 #endif
15 
16 #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
17 
18 #ifndef __ASSEMBLY__
19 extern atomic_t modifying_ftrace_code;
20 extern void __fentry__(void);
21 
22 static inline unsigned long ftrace_call_adjust(unsigned long addr)
23 {
24 	/*
25 	 * addr is the address of the mcount call instruction.
26 	 * recordmcount does the necessary offset calculation.
27 	 */
28 	return addr;
29 }
30 
31 /*
32  * When a ftrace registered caller is tracing a function that is
33  * also set by a register_ftrace_direct() call, it needs to be
34  * differentiated in the ftrace_caller trampoline. To do this, we
35  * place the direct caller in the ORIG_AX part of pt_regs. This
36  * tells the ftrace_caller that there's a direct caller.
37  */
38 static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
39 {
40 	/* Emulate a call */
41 	regs->orig_ax = addr;
42 }
43 
44 #ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
45 struct ftrace_regs {
46 	struct pt_regs		regs;
47 };
48 
49 static __always_inline struct pt_regs *
50 arch_ftrace_get_regs(struct ftrace_regs *fregs)
51 {
52 	/* Only when FL_SAVE_REGS is set, cs will be non zero */
53 	if (!fregs->regs.cs)
54 		return NULL;
55 	return &fregs->regs;
56 }
57 
58 #define ftrace_instruction_pointer_set(fregs, _ip)	\
59 	do { (fregs)->regs.ip = (_ip); } while (0)
60 #endif
61 
62 #ifdef CONFIG_DYNAMIC_FTRACE
63 
64 struct dyn_arch_ftrace {
65 	/* No extra data needed for x86 */
66 };
67 
68 #define FTRACE_GRAPH_TRAMP_ADDR FTRACE_GRAPH_ADDR
69 
70 #endif /*  CONFIG_DYNAMIC_FTRACE */
71 #endif /* __ASSEMBLY__ */
72 #endif /* CONFIG_FUNCTION_TRACER */
73 
74 
75 #ifndef __ASSEMBLY__
76 
77 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
78 extern void set_ftrace_ops_ro(void);
79 #else
80 static inline void set_ftrace_ops_ro(void) { }
81 #endif
82 
83 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
84 static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
85 {
86 	/*
87 	 * Compare the symbol name with the system call name. Skip the
88 	 * "__x64_sys", "__ia32_sys", "__do_sys" or simple "sys" prefix.
89 	 */
90 	return !strcmp(sym + 3, name + 3) ||
91 		(!strncmp(sym, "__x64_", 6) && !strcmp(sym + 9, name + 3)) ||
92 		(!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3)) ||
93 		(!strncmp(sym, "__do_sys", 8) && !strcmp(sym + 8, name + 3));
94 }
95 
96 #ifndef COMPILE_OFFSETS
97 
98 #if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_IA32_EMULATION)
99 #include <linux/compat.h>
100 
101 /*
102  * Because ia32 syscalls do not map to x86_64 syscall numbers
103  * this screws up the trace output when tracing a ia32 task.
104  * Instead of reporting bogus syscalls, just do not trace them.
105  *
106  * If the user really wants these, then they should use the
107  * raw syscall tracepoints with filtering.
108  */
109 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 1
110 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
111 {
112 	return in_32bit_syscall();
113 }
114 #endif /* CONFIG_FTRACE_SYSCALLS && CONFIG_IA32_EMULATION */
115 #endif /* !COMPILE_OFFSETS */
116 #endif /* !__ASSEMBLY__ */
117 
118 #endif /* _ASM_X86_FTRACE_H */
119