xref: /linux/arch/x86/include/asm/ftrace.h (revision cbba5d1b53fb82209feacb459edecb1ef8427119)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_FTRACE_H
3 #define _ASM_X86_FTRACE_H
4 
5 #include <asm/ptrace.h>
6 
7 #ifdef CONFIG_FUNCTION_TRACER
8 #ifndef CC_USING_FENTRY
9 # error Compiler does not support fentry?
10 #endif
11 # define MCOUNT_ADDR		((unsigned long)(__fentry__))
12 #define MCOUNT_INSN_SIZE	5 /* sizeof mcount call */
13 
14 /* Ignore unused weak functions which will have non zero offsets */
15 #ifdef CONFIG_HAVE_FENTRY
16 # include <asm/ibt.h>
17 /* Add offset for endbr64 if IBT enabled */
18 # define FTRACE_MCOUNT_MAX_OFFSET	ENDBR_INSN_SIZE
19 #endif
20 
21 #ifdef CONFIG_DYNAMIC_FTRACE
22 #define ARCH_SUPPORTS_FTRACE_OPS 1
23 #endif
24 
25 #ifndef __ASSEMBLER__
26 extern void __fentry__(void);
27 
ftrace_call_adjust(unsigned long addr)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 
arch_ftrace_get_symaddr(unsigned long fentry_ip)37 static inline unsigned long arch_ftrace_get_symaddr(unsigned long fentry_ip)
38 {
39 	if (is_endbr((void*)(fentry_ip - ENDBR_INSN_SIZE)))
40 		fentry_ip -= ENDBR_INSN_SIZE;
41 
42 	return fentry_ip;
43 }
44 #define ftrace_get_symaddr(fentry_ip)	arch_ftrace_get_symaddr(fentry_ip)
45 
46 #ifdef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
47 
48 #include <linux/ftrace_regs.h>
49 
50 static __always_inline struct pt_regs *
arch_ftrace_get_regs(struct ftrace_regs * fregs)51 arch_ftrace_get_regs(struct ftrace_regs *fregs)
52 {
53 	/* Only when FL_SAVE_REGS is set, cs will be non zero */
54 	if (!arch_ftrace_regs(fregs)->regs.cs)
55 		return NULL;
56 	return &arch_ftrace_regs(fregs)->regs;
57 }
58 
59 #define arch_ftrace_partial_regs(regs) do {	\
60 	regs->flags &= ~X86_EFLAGS_FIXED;	\
61 	regs->cs = __KERNEL_CS;			\
62 } while (0)
63 
64 #define arch_ftrace_fill_perf_regs(fregs, _regs) do {	\
65 		(_regs)->ip = arch_ftrace_regs(fregs)->regs.ip;		\
66 		(_regs)->sp = arch_ftrace_regs(fregs)->regs.sp;		\
67 		(_regs)->cs = __KERNEL_CS;		\
68 		(_regs)->flags = 0;			\
69 	} while (0)
70 
71 #define ftrace_regs_set_instruction_pointer(fregs, _ip)	\
72 	do { arch_ftrace_regs(fregs)->regs.ip = (_ip); } while (0)
73 
74 
75 static __always_inline unsigned long
ftrace_regs_get_return_address(struct ftrace_regs * fregs)76 ftrace_regs_get_return_address(struct ftrace_regs *fregs)
77 {
78 	return *(unsigned long *)ftrace_regs_get_stack_pointer(fregs);
79 }
80 
81 struct ftrace_ops;
82 #define ftrace_graph_func ftrace_graph_func
83 void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
84 		       struct ftrace_ops *op, struct ftrace_regs *fregs);
85 #else
86 #define FTRACE_GRAPH_TRAMP_ADDR FTRACE_GRAPH_ADDR
87 #endif
88 
89 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
90 /*
91  * When a ftrace registered caller is tracing a function that is
92  * also set by a register_ftrace_direct() call, it needs to be
93  * differentiated in the ftrace_caller trampoline. To do this, we
94  * place the direct caller in the ORIG_AX part of pt_regs. This
95  * tells the ftrace_caller that there's a direct caller.
96  */
97 static inline void
__arch_ftrace_set_direct_caller(struct pt_regs * regs,unsigned long addr)98 __arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
99 {
100 	/* Emulate a call */
101 	regs->orig_ax = addr;
102 }
103 #define arch_ftrace_set_direct_caller(fregs, addr) \
104 	__arch_ftrace_set_direct_caller(&arch_ftrace_regs(fregs)->regs, addr)
105 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
106 
107 #ifdef CONFIG_DYNAMIC_FTRACE
108 
109 struct dyn_arch_ftrace {
110 	/* No extra data needed for x86 */
111 };
112 
113 #endif /*  CONFIG_DYNAMIC_FTRACE */
114 #endif /* __ASSEMBLER__ */
115 #endif /* CONFIG_FUNCTION_TRACER */
116 
117 
118 #ifndef __ASSEMBLER__
119 
120 void prepare_ftrace_return(unsigned long ip, unsigned long *parent,
121 			   unsigned long frame_pointer);
122 
123 #if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
124 extern void set_ftrace_ops_ro(void);
125 #else
set_ftrace_ops_ro(void)126 static inline void set_ftrace_ops_ro(void) { }
127 #endif
128 
129 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
arch_syscall_match_sym_name(const char * sym,const char * name)130 static inline bool arch_syscall_match_sym_name(const char *sym, const char *name)
131 {
132 	/*
133 	 * Compare the symbol name with the system call name. Skip the
134 	 * "__x64_sys", "__ia32_sys", "__do_sys" or simple "sys" prefix.
135 	 */
136 	return !strcmp(sym + 3, name + 3) ||
137 		(!strncmp(sym, "__x64_", 6) && !strcmp(sym + 9, name + 3)) ||
138 		(!strncmp(sym, "__ia32_", 7) && !strcmp(sym + 10, name + 3)) ||
139 		(!strncmp(sym, "__do_sys", 8) && !strcmp(sym + 8, name + 3));
140 }
141 
142 #ifndef COMPILE_OFFSETS
143 
144 #if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_IA32_EMULATION)
145 #include <linux/compat.h>
146 
147 /*
148  * Because ia32 syscalls do not map to x86_64 syscall numbers
149  * this screws up the trace output when tracing a ia32 task.
150  * Instead of reporting bogus syscalls, just do not trace them.
151  *
152  * If the user really wants these, then they should use the
153  * raw syscall tracepoints with filtering.
154  */
155 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 1
arch_trace_is_compat_syscall(struct pt_regs * regs)156 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
157 {
158 	return in_32bit_syscall();
159 }
160 #endif /* CONFIG_FTRACE_SYSCALLS && CONFIG_IA32_EMULATION */
161 #endif /* !COMPILE_OFFSETS */
162 #endif /* !__ASSEMBLER__ */
163 
164 #endif /* _ASM_X86_FTRACE_H */
165