xref: /openbmc/linux/arch/x86/include/asm/ftrace.h (revision ac73d4bf)
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 void __fentry__(void);
27 
28 static inline unsigned long ftrace_call_adjust(unsigned long addr)
29 {
30 	/*
31 	 * addr is the address of the mcount call instruction.
32 	 * recordmcount does the necessary offset calculation.
33 	 */
34 	return addr;
35 }
36 
37 /*
38  * When a ftrace registered caller is tracing a function that is
39  * also set by a register_ftrace_direct() call, it needs to be
40  * differentiated in the ftrace_caller trampoline. To do this, we
41  * place the direct caller in the ORIG_AX part of pt_regs. This
42  * tells the ftrace_caller that there's a direct caller.
43  */
44 static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
45 {
46 	/* Emulate a call */
47 	regs->orig_ax = addr;
48 }
49 
50 #ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
51 struct ftrace_regs {
52 	struct pt_regs		regs;
53 };
54 
55 static __always_inline struct pt_regs *
56 arch_ftrace_get_regs(struct ftrace_regs *fregs)
57 {
58 	/* Only when FL_SAVE_REGS is set, cs will be non zero */
59 	if (!fregs->regs.cs)
60 		return NULL;
61 	return &fregs->regs;
62 }
63 
64 #define ftrace_instruction_pointer_set(fregs, _ip)	\
65 	do { (fregs)->regs.ip = (_ip); } while (0)
66 
67 struct ftrace_ops;
68 #define ftrace_graph_func ftrace_graph_func
69 void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
70 		       struct ftrace_ops *op, struct ftrace_regs *fregs);
71 #else
72 #define FTRACE_GRAPH_TRAMP_ADDR FTRACE_GRAPH_ADDR
73 #endif
74 
75 #ifdef CONFIG_DYNAMIC_FTRACE
76 
77 struct dyn_arch_ftrace {
78 	/* No extra data needed for x86 */
79 };
80 
81 #endif /*  CONFIG_DYNAMIC_FTRACE */
82 #endif /* __ASSEMBLY__ */
83 #endif /* CONFIG_FUNCTION_TRACER */
84 
85 
86 #ifndef __ASSEMBLY__
87 
88 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
89 extern void set_ftrace_ops_ro(void);
90 #else
91 static inline void set_ftrace_ops_ro(void) { }
92 #endif
93 
94 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
95 static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
96 {
97 	/*
98 	 * Compare the symbol name with the system call name. Skip the
99 	 * "__x64_sys", "__ia32_sys", "__do_sys" or simple "sys" prefix.
100 	 */
101 	return !strcmp(sym + 3, name + 3) ||
102 		(!strncmp(sym, "__x64_", 6) && !strcmp(sym + 9, name + 3)) ||
103 		(!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3)) ||
104 		(!strncmp(sym, "__do_sys", 8) && !strcmp(sym + 8, name + 3));
105 }
106 
107 #ifndef COMPILE_OFFSETS
108 
109 #if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_IA32_EMULATION)
110 #include <linux/compat.h>
111 
112 /*
113  * Because ia32 syscalls do not map to x86_64 syscall numbers
114  * this screws up the trace output when tracing a ia32 task.
115  * Instead of reporting bogus syscalls, just do not trace them.
116  *
117  * If the user really wants these, then they should use the
118  * raw syscall tracepoints with filtering.
119  */
120 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 1
121 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
122 {
123 	return in_32bit_syscall();
124 }
125 #endif /* CONFIG_FTRACE_SYSCALLS && CONFIG_IA32_EMULATION */
126 #endif /* !COMPILE_OFFSETS */
127 #endif /* !__ASSEMBLY__ */
128 
129 #endif /* _ASM_X86_FTRACE_H */
130