xref: /openbmc/linux/arch/arm64/include/asm/ftrace.h (revision 750afb08)
1 /*
2  * arch/arm64/include/asm/ftrace.h
3  *
4  * Copyright (C) 2013 Linaro Limited
5  * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #ifndef __ASM_FTRACE_H
12 #define __ASM_FTRACE_H
13 
14 #include <asm/insn.h>
15 
16 #define HAVE_FUNCTION_GRAPH_FP_TEST
17 #define MCOUNT_ADDR		((unsigned long)_mcount)
18 #define MCOUNT_INSN_SIZE	AARCH64_INSN_SIZE
19 
20 #ifndef __ASSEMBLY__
21 #include <linux/compat.h>
22 
23 extern void _mcount(unsigned long);
24 extern void *return_address(unsigned int);
25 
26 struct dyn_arch_ftrace {
27 	/* No extra data needed for arm64 */
28 };
29 
30 extern unsigned long ftrace_graph_call;
31 
32 extern void return_to_handler(void);
33 
34 static inline unsigned long ftrace_call_adjust(unsigned long addr)
35 {
36 	/*
37 	 * addr is the address of the mcount call instruction.
38 	 * recordmcount does the necessary offset calculation.
39 	 */
40 	return addr;
41 }
42 
43 #define ftrace_return_address(n) return_address(n)
44 
45 /*
46  * Because AArch32 mode does not share the same syscall table with AArch64,
47  * tracing compat syscalls may result in reporting bogus syscalls or even
48  * hang-up, so just do not trace them.
49  * See kernel/trace/trace_syscalls.c
50  *
51  * x86 code says:
52  * If the user really wants these, then they should use the
53  * raw syscall tracepoints with filtering.
54  */
55 #define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
56 static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
57 {
58 	return is_compat_task();
59 }
60 
61 #define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
62 
63 static inline bool arch_syscall_match_sym_name(const char *sym,
64 					       const char *name)
65 {
66 	/*
67 	 * Since all syscall functions have __arm64_ prefix, we must skip it.
68 	 * However, as we described above, we decided to ignore compat
69 	 * syscalls, so we don't care about __arm64_compat_ prefix here.
70 	 */
71 	return !strcmp(sym + 8, name);
72 }
73 #endif /* ifndef __ASSEMBLY__ */
74 
75 #endif /* __ASM_FTRACE_H */
76