1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * arch/arm64/include/asm/ftrace.h
 4 *
 5 * Copyright (C) 2013 Linaro Limited
 6 * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
 7 */
 8#ifndef __ASM_FTRACE_H
 9#define __ASM_FTRACE_H
10
11#include <asm/insn.h>
12
13#define HAVE_FUNCTION_GRAPH_FP_TEST
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
14#define MCOUNT_ADDR		((unsigned long)_mcount)
 
 
 
15#define MCOUNT_INSN_SIZE	AARCH64_INSN_SIZE
16
 
 
 
17/*
18 * Currently, gcc tends to save the link register after the local variables
19 * on the stack. This causes the max stack tracer to report the function
20 * frame sizes for the wrong functions. By defining
21 * ARCH_FTRACE_SHIFT_STACK_TRACER, it will tell the stack tracer to expect
22 * to find the return address on the stack after the local variables have
23 * been set up.
24 *
25 * Note, this may change in the future, and we will need to deal with that
26 * if it were to happen.
27 */
28#define ARCH_FTRACE_SHIFT_STACK_TRACER 1
29
30#ifndef __ASSEMBLY__
31#include <linux/compat.h>
32
33extern void _mcount(unsigned long);
34extern void *return_address(unsigned int);
35
36struct dyn_arch_ftrace {
37	/* No extra data needed for arm64 */
38};
39
40extern unsigned long ftrace_graph_call;
41
42extern void return_to_handler(void);
43
44static inline unsigned long ftrace_call_adjust(unsigned long addr)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
45{
46	/*
47	 * addr is the address of the mcount call instruction.
48	 * recordmcount does the necessary offset calculation.
49	 */
50	return addr;
51}
 
 
 
52
53#define ftrace_return_address(n) return_address(n)
54
55/*
56 * Because AArch32 mode does not share the same syscall table with AArch64,
57 * tracing compat syscalls may result in reporting bogus syscalls or even
58 * hang-up, so just do not trace them.
59 * See kernel/trace/trace_syscalls.c
60 *
61 * x86 code says:
62 * If the user really wants these, then they should use the
63 * raw syscall tracepoints with filtering.
64 */
65#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
66static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
67{
68	return is_compat_task();
69}
70
71#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
72
73static inline bool arch_syscall_match_sym_name(const char *sym,
74					       const char *name)
75{
76	/*
77	 * Since all syscall functions have __arm64_ prefix, we must skip it.
78	 * However, as we described above, we decided to ignore compat
79	 * syscalls, so we don't care about __arm64_compat_ prefix here.
80	 */
81	return !strcmp(sym + 8, name);
82}
83#endif /* ifndef __ASSEMBLY__ */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
84
85#endif /* __ASM_FTRACE_H */

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * arch/arm64/include/asm/ftrace.h
  4 *
  5 * Copyright (C) 2013 Linaro Limited
  6 * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
  7 */
  8#ifndef __ASM_FTRACE_H
  9#define __ASM_FTRACE_H
 10
 11#include <asm/insn.h>
 12
 13#define HAVE_FUNCTION_GRAPH_FP_TEST
 14
 15/*
 16 * HAVE_FUNCTION_GRAPH_RET_ADDR_PTR means that the architecture can provide a
 17 * "return address pointer" which can be used to uniquely identify a return
 18 * address which has been overwritten.
 19 *
 20 * On arm64 we use the address of the caller's frame record, which remains the
 21 * same for the lifetime of the instrumented function, unlike the return
 22 * address in the LR.
 23 */
 24#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
 25
 26#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
 27#define ARCH_SUPPORTS_FTRACE_OPS 1
 28#else
 29#define MCOUNT_ADDR		((unsigned long)_mcount)
 30#endif
 31
 32/* The BL at the callsite's adjusted rec->ip */
 33#define MCOUNT_INSN_SIZE	AARCH64_INSN_SIZE
 34
 35#define FTRACE_PLT_IDX		0
 36#define NR_FTRACE_PLTS		1
 37
 38/*
 39 * Currently, gcc tends to save the link register after the local variables
 40 * on the stack. This causes the max stack tracer to report the function
 41 * frame sizes for the wrong functions. By defining
 42 * ARCH_FTRACE_SHIFT_STACK_TRACER, it will tell the stack tracer to expect
 43 * to find the return address on the stack after the local variables have
 44 * been set up.
 45 *
 46 * Note, this may change in the future, and we will need to deal with that
 47 * if it were to happen.
 48 */
 49#define ARCH_FTRACE_SHIFT_STACK_TRACER 1
 50
 51#ifndef __ASSEMBLY__
 52#include <linux/compat.h>
 53
 54extern void _mcount(unsigned long);
 55extern void *return_address(unsigned int);
 56
 57struct dyn_arch_ftrace {
 58	/* No extra data needed for arm64 */
 59};
 60
 61extern unsigned long ftrace_graph_call;
 62
 63extern void return_to_handler(void);
 64
 65unsigned long ftrace_call_adjust(unsigned long addr);
 66
 67#ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
 68struct dyn_ftrace;
 69struct ftrace_ops;
 70
 71#define arch_ftrace_get_regs(regs) NULL
 72
 73/*
 74 * Note: sizeof(struct ftrace_regs) must be a multiple of 16 to ensure correct
 75 * stack alignment
 76 */
 77struct ftrace_regs {
 78	/* x0 - x8 */
 79	unsigned long regs[9];
 80
 81#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
 82	unsigned long direct_tramp;
 83#else
 84	unsigned long __unused;
 85#endif
 86
 87	unsigned long fp;
 88	unsigned long lr;
 89
 90	unsigned long sp;
 91	unsigned long pc;
 92};
 93
 94static __always_inline unsigned long
 95ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs)
 96{
 97	return fregs->pc;
 98}
 99
100static __always_inline void
101ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
102				    unsigned long pc)
103{
104	fregs->pc = pc;
105}
106
107static __always_inline unsigned long
108ftrace_regs_get_stack_pointer(const struct ftrace_regs *fregs)
109{
110	return fregs->sp;
111}
112
113static __always_inline unsigned long
114ftrace_regs_get_argument(struct ftrace_regs *fregs, unsigned int n)
115{
116	if (n < 8)
117		return fregs->regs[n];
118	return 0;
119}
120
121static __always_inline unsigned long
122ftrace_regs_get_return_value(const struct ftrace_regs *fregs)
123{
124	return fregs->regs[0];
125}
126
127static __always_inline void
128ftrace_regs_set_return_value(struct ftrace_regs *fregs,
129			     unsigned long ret)
130{
131	fregs->regs[0] = ret;
132}
133
134static __always_inline void
135ftrace_override_function_with_return(struct ftrace_regs *fregs)
136{
137	fregs->pc = fregs->lr;
138}
139
140int ftrace_regs_query_register_offset(const char *name);
141
142int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
143#define ftrace_init_nop ftrace_init_nop
144
145void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
146		       struct ftrace_ops *op, struct ftrace_regs *fregs);
147#define ftrace_graph_func ftrace_graph_func
148
149#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
150static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs,
151						 unsigned long addr)
152{
153	/*
154	 * The ftrace trampoline will return to this address instead of the
155	 * instrumented function.
156	 */
157	fregs->direct_tramp = addr;
158}
159#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
160
161#endif
162
163#define ftrace_return_address(n) return_address(n)
164
165/*
166 * Because AArch32 mode does not share the same syscall table with AArch64,
167 * tracing compat syscalls may result in reporting bogus syscalls or even
168 * hang-up, so just do not trace them.
169 * See kernel/trace/trace_syscalls.c
170 *
171 * x86 code says:
172 * If the user really wants these, then they should use the
173 * raw syscall tracepoints with filtering.
174 */
175#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
176static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
177{
178	return is_compat_task();
179}
180
181#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
182
183static inline bool arch_syscall_match_sym_name(const char *sym,
184					       const char *name)
185{
186	/*
187	 * Since all syscall functions have __arm64_ prefix, we must skip it.
188	 * However, as we described above, we decided to ignore compat
189	 * syscalls, so we don't care about __arm64_compat_ prefix here.
190	 */
191	return !strcmp(sym + 8, name);
192}
193#endif /* ifndef __ASSEMBLY__ */
194
195#ifndef __ASSEMBLY__
196#ifdef CONFIG_FUNCTION_GRAPH_TRACER
197struct fgraph_ret_regs {
198	/* x0 - x7 */
199	unsigned long regs[8];
200
201	unsigned long fp;
202	unsigned long __unused;
203};
204
205static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
206{
207	return ret_regs->regs[0];
208}
209
210static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
211{
212	return ret_regs->fp;
213}
214
215void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
216			   unsigned long frame_pointer);
217
218#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER  */
219#endif
220
221#endif /* __ASM_FTRACE_H */