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e18eead3 SR |
1 | /* |
2 | * linux/arch/x86_64/mcount_64.S | |
3 | * | |
4 | * Copyright (C) 2014 Steven Rostedt, Red Hat Inc | |
5 | */ | |
6 | ||
7 | #include <linux/linkage.h> | |
8 | #include <asm/ptrace.h> | |
9 | #include <asm/ftrace.h> | |
10 | ||
11 | ||
12 | .code64 | |
13 | .section .entry.text, "ax" | |
14 | ||
15 | ||
16 | #ifdef CONFIG_FUNCTION_TRACER | |
17 | ||
18 | #ifdef CC_USING_FENTRY | |
19 | # define function_hook __fentry__ | |
20 | #else | |
21 | # define function_hook mcount | |
22 | #endif | |
23 | ||
24 | #ifdef CONFIG_DYNAMIC_FTRACE | |
25 | ||
26 | ENTRY(function_hook) | |
27 | retq | |
28 | END(function_hook) | |
29 | ||
30 | /* skip is set if stack has been adjusted */ | |
f3bea491 | 31 | .macro ftrace_caller_setup trace_label skip=0 |
e18eead3 SR |
32 | MCOUNT_SAVE_FRAME \skip |
33 | ||
f3bea491 SRRH |
34 | /* Save this location */ |
35 | GLOBAL(\trace_label) | |
e18eead3 SR |
36 | /* Load the ftrace_ops into the 3rd parameter */ |
37 | movq function_trace_op(%rip), %rdx | |
38 | ||
39 | /* Load ip into the first parameter */ | |
40 | movq RIP(%rsp), %rdi | |
41 | subq $MCOUNT_INSN_SIZE, %rdi | |
42 | /* Load the parent_ip into the second parameter */ | |
43 | #ifdef CC_USING_FENTRY | |
44 | movq SS+16(%rsp), %rsi | |
45 | #else | |
46 | movq 8(%rbp), %rsi | |
47 | #endif | |
48 | .endm | |
49 | ||
9960efeb SRRH |
50 | #ifdef CONFIG_FRAME_POINTER |
51 | /* | |
52 | * Stack traces will stop at the ftrace trampoline if the frame pointer | |
53 | * is not set up properly. If fentry is used, we need to save a frame | |
54 | * pointer for the parent as well as the function traced, because the | |
55 | * fentry is called before the stack frame is set up, where as mcount | |
56 | * is called afterward. | |
57 | */ | |
58 | .macro create_frame parent rip | |
59 | #ifdef CC_USING_FENTRY | |
60 | pushq \parent | |
61 | pushq %rbp | |
62 | movq %rsp, %rbp | |
63 | #endif | |
64 | pushq \rip | |
65 | pushq %rbp | |
66 | movq %rsp, %rbp | |
67 | .endm | |
68 | ||
69 | .macro restore_frame | |
70 | #ifdef CC_USING_FENTRY | |
71 | addq $16, %rsp | |
72 | #endif | |
73 | popq %rbp | |
74 | addq $8, %rsp | |
75 | .endm | |
76 | #else | |
77 | .macro create_frame parent rip | |
78 | .endm | |
79 | .macro restore_frame | |
80 | .endm | |
81 | #endif /* CONFIG_FRAME_POINTER */ | |
82 | ||
e18eead3 | 83 | ENTRY(ftrace_caller) |
f3bea491 | 84 | ftrace_caller_setup ftrace_caller_op_ptr |
e18eead3 SR |
85 | /* regs go into 4th parameter (but make it NULL) */ |
86 | movq $0, %rcx | |
87 | ||
9960efeb SRRH |
88 | create_frame %rsi, %rdi |
89 | ||
e18eead3 SR |
90 | GLOBAL(ftrace_call) |
91 | call ftrace_stub | |
92 | ||
9960efeb SRRH |
93 | restore_frame |
94 | ||
e18eead3 | 95 | MCOUNT_RESTORE_FRAME |
f3bea491 SRRH |
96 | |
97 | /* | |
98 | * The copied trampoline must call ftrace_return as it | |
99 | * still may need to call the function graph tracer. | |
100 | */ | |
101 | GLOBAL(ftrace_caller_end) | |
102 | ||
103 | GLOBAL(ftrace_return) | |
e18eead3 SR |
104 | |
105 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
106 | GLOBAL(ftrace_graph_call) | |
107 | jmp ftrace_stub | |
108 | #endif | |
109 | ||
110 | GLOBAL(ftrace_stub) | |
111 | retq | |
112 | END(ftrace_caller) | |
113 | ||
114 | ENTRY(ftrace_regs_caller) | |
115 | /* Save the current flags before compare (in SS location)*/ | |
116 | pushfq | |
117 | ||
e18eead3 | 118 | /* skip=8 to skip flags saved in SS */ |
f3bea491 | 119 | ftrace_caller_setup ftrace_regs_caller_op_ptr 8 |
e18eead3 SR |
120 | |
121 | /* Save the rest of pt_regs */ | |
122 | movq %r15, R15(%rsp) | |
123 | movq %r14, R14(%rsp) | |
124 | movq %r13, R13(%rsp) | |
125 | movq %r12, R12(%rsp) | |
126 | movq %r11, R11(%rsp) | |
127 | movq %r10, R10(%rsp) | |
128 | movq %rbp, RBP(%rsp) | |
129 | movq %rbx, RBX(%rsp) | |
130 | /* Copy saved flags */ | |
131 | movq SS(%rsp), %rcx | |
132 | movq %rcx, EFLAGS(%rsp) | |
133 | /* Kernel segments */ | |
134 | movq $__KERNEL_DS, %rcx | |
135 | movq %rcx, SS(%rsp) | |
136 | movq $__KERNEL_CS, %rcx | |
137 | movq %rcx, CS(%rsp) | |
138 | /* Stack - skipping return address */ | |
139 | leaq SS+16(%rsp), %rcx | |
140 | movq %rcx, RSP(%rsp) | |
141 | ||
142 | /* regs go into 4th parameter */ | |
143 | leaq (%rsp), %rcx | |
144 | ||
9960efeb SRRH |
145 | create_frame %rsi, %rdi |
146 | ||
e18eead3 SR |
147 | GLOBAL(ftrace_regs_call) |
148 | call ftrace_stub | |
149 | ||
9960efeb SRRH |
150 | restore_frame |
151 | ||
e18eead3 SR |
152 | /* Copy flags back to SS, to restore them */ |
153 | movq EFLAGS(%rsp), %rax | |
154 | movq %rax, SS(%rsp) | |
155 | ||
156 | /* Handlers can change the RIP */ | |
157 | movq RIP(%rsp), %rax | |
158 | movq %rax, SS+8(%rsp) | |
159 | ||
160 | /* restore the rest of pt_regs */ | |
161 | movq R15(%rsp), %r15 | |
162 | movq R14(%rsp), %r14 | |
163 | movq R13(%rsp), %r13 | |
164 | movq R12(%rsp), %r12 | |
165 | movq R10(%rsp), %r10 | |
166 | movq RBP(%rsp), %rbp | |
167 | movq RBX(%rsp), %rbx | |
168 | ||
169 | /* skip=8 to skip flags saved in SS */ | |
170 | MCOUNT_RESTORE_FRAME 8 | |
171 | ||
172 | /* Restore flags */ | |
173 | popfq | |
174 | ||
f3bea491 SRRH |
175 | /* |
176 | * As this jmp to ftrace_return can be a short jump | |
177 | * it must not be copied into the trampoline. | |
178 | * The trampoline will add the code to jump | |
179 | * to the return. | |
180 | */ | |
181 | GLOBAL(ftrace_regs_caller_end) | |
182 | ||
e18eead3 | 183 | jmp ftrace_return |
fdc841b5 | 184 | |
e18eead3 SR |
185 | popfq |
186 | jmp ftrace_stub | |
187 | ||
188 | END(ftrace_regs_caller) | |
189 | ||
190 | ||
191 | #else /* ! CONFIG_DYNAMIC_FTRACE */ | |
192 | ||
193 | ENTRY(function_hook) | |
e18eead3 SR |
194 | cmpq $ftrace_stub, ftrace_trace_function |
195 | jnz trace | |
196 | ||
197 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
198 | cmpq $ftrace_stub, ftrace_graph_return | |
199 | jnz ftrace_graph_caller | |
200 | ||
201 | cmpq $ftrace_graph_entry_stub, ftrace_graph_entry | |
202 | jnz ftrace_graph_caller | |
203 | #endif | |
204 | ||
205 | GLOBAL(ftrace_stub) | |
206 | retq | |
207 | ||
208 | trace: | |
209 | MCOUNT_SAVE_FRAME | |
210 | ||
211 | movq RIP(%rsp), %rdi | |
212 | #ifdef CC_USING_FENTRY | |
213 | movq SS+16(%rsp), %rsi | |
214 | #else | |
215 | movq 8(%rbp), %rsi | |
216 | #endif | |
217 | subq $MCOUNT_INSN_SIZE, %rdi | |
218 | ||
219 | call *ftrace_trace_function | |
220 | ||
221 | MCOUNT_RESTORE_FRAME | |
222 | ||
223 | jmp ftrace_stub | |
224 | END(function_hook) | |
225 | #endif /* CONFIG_DYNAMIC_FTRACE */ | |
226 | #endif /* CONFIG_FUNCTION_TRACER */ | |
227 | ||
228 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
229 | ENTRY(ftrace_graph_caller) | |
230 | MCOUNT_SAVE_FRAME | |
231 | ||
232 | #ifdef CC_USING_FENTRY | |
233 | leaq SS+16(%rsp), %rdi | |
234 | movq $0, %rdx /* No framepointers needed */ | |
235 | #else | |
236 | leaq 8(%rbp), %rdi | |
237 | movq (%rbp), %rdx | |
238 | #endif | |
239 | movq RIP(%rsp), %rsi | |
240 | subq $MCOUNT_INSN_SIZE, %rsi | |
241 | ||
242 | call prepare_ftrace_return | |
243 | ||
244 | MCOUNT_RESTORE_FRAME | |
245 | ||
246 | retq | |
247 | END(ftrace_graph_caller) | |
248 | ||
249 | GLOBAL(return_to_handler) | |
250 | subq $24, %rsp | |
251 | ||
252 | /* Save the return values */ | |
253 | movq %rax, (%rsp) | |
254 | movq %rdx, 8(%rsp) | |
255 | movq %rbp, %rdi | |
256 | ||
257 | call ftrace_return_to_handler | |
258 | ||
259 | movq %rax, %rdi | |
260 | movq 8(%rsp), %rdx | |
261 | movq (%rsp), %rax | |
262 | addq $24, %rsp | |
263 | jmp *%rdi | |
264 | #endif |