xref: /openbmc/linux/arch/x86/include/asm/ftrace.h (revision 6726d552)
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 /* Ignore unused weak functions which will have non zero offsets */
13 #ifdef CONFIG_HAVE_FENTRY
14 # include <asm/ibt.h>
15 /* Add offset for endbr64 if IBT enabled */
16 # define FTRACE_MCOUNT_MAX_OFFSET	ENDBR_INSN_SIZE
17 #endif
18 
19 #ifdef CONFIG_DYNAMIC_FTRACE
20 #define ARCH_SUPPORTS_FTRACE_OPS 1
21 #endif
22 
23 #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
24 
25 #ifndef __ASSEMBLY__
26 extern atomic_t modifying_ftrace_code;
27 extern void __fentry__(void);
28 
29 static inline unsigned long ftrace_call_adjust(unsigned long addr)
30 {
31 	/*
32 	 * addr is the address of the mcount call instruction.
33 	 * recordmcount does the necessary offset calculation.
34 	 */
35 	return addr;
36 }
37 
38 /*
39  * When a ftrace registered caller is tracing a function that is
40  * also set by a register_ftrace_direct() call, it needs to be
41  * differentiated in the ftrace_caller trampoline. To do this, we
42  * place the direct caller in the ORIG_AX part of pt_regs. This
43  * tells the ftrace_caller that there's a direct caller.
44  */
45 static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
46 {
47 	/* Emulate a call */
48 	regs->orig_ax = addr;
49 }
50 
51 #ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
52 struct ftrace_regs {
53 	struct pt_regs		regs;
54 };
55 
56 static __always_inline struct pt_regs *
57 arch_ftrace_get_regs(struct ftrace_regs *fregs)
58 {
59 	/* Only when FL_SAVE_REGS is set, cs will be non zero */
60 	if (!fregs->regs.cs)
61 		return NULL;
62 	return &fregs->regs;
63 }
64 
65 #define ftrace_instruction_pointer_set(fregs, _ip)	\
66 	do { (fregs)->regs.ip = (_ip); } while (0)
67 
68 struct ftrace_ops;
69 #define ftrace_graph_func ftrace_graph_func
70 void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
71 		       struct ftrace_ops *op, struct ftrace_regs *fregs);
72 #else
73 #define FTRACE_GRAPH_TRAMP_ADDR FTRACE_GRAPH_ADDR
74 #endif
75 
76 #ifdef CONFIG_DYNAMIC_FTRACE
77 
78 struct dyn_arch_ftrace {
79 	/* No extra data needed for x86 */
80 };
81 
82 #endif /*  CONFIG_DYNAMIC_FTRACE */
83 #endif /* __ASSEMBLY__ */
84 #endif /* CONFIG_FUNCTION_TRACER */
85 
86 
87 #ifndef __ASSEMBLY__
88 
89 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
90 extern void set_ftrace_ops_ro(void);
91 #else
92 static inline void set_ftrace_ops_ro(void) { }
93 #endif
94 
95 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
96 static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
97 {
98 	/*
99 	 * Compare the symbol name with the system call name. Skip the
100 	 * "__x64_sys", "__ia32_sys", "__do_sys" or simple "sys" prefix.
101 	 */
102 	return !strcmp(sym + 3, name + 3) ||
103 		(!strncmp(sym, "__x64_", 6) && !strcmp(sym + 9, name + 3)) ||
104 		(!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3)) ||
105 		(!strncmp(sym, "__do_sys", 8) && !strcmp(sym + 8, name + 3));
106 }
107 
108 #ifndef COMPILE_OFFSETS
109 
110 #if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_IA32_EMULATION)
111 #include <linux/compat.h>
112 
113 /*
114  * Because ia32 syscalls do not map to x86_64 syscall numbers
115  * this screws up the trace output when tracing a ia32 task.
116  * Instead of reporting bogus syscalls, just do not trace them.
117  *
118  * If the user really wants these, then they should use the
119  * raw syscall tracepoints with filtering.
120  */
121 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 1
122 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
123 {
124 	return in_32bit_syscall();
125 }
126 #endif /* CONFIG_FTRACE_SYSCALLS && CONFIG_IA32_EMULATION */
127 #endif /* !COMPILE_OFFSETS */
128 #endif /* !__ASSEMBLY__ */
129 
130 #endif /* _ASM_X86_FTRACE_H */
131