1//===-- xray_trampoline_x86.s -----------------------------------*- ASM -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file is a part of XRay, a dynamic runtime instrumentation system.
10//
11// This implements the X86-specific assembler for the trampolines.
12//
13//===----------------------------------------------------------------------===//
14
15#include "../builtins/assembly.h"
16#include "../sanitizer_common/sanitizer_asm.h"
17
18// XRay trampolines which are not produced by intrinsics are not System V AMD64
19// ABI compliant because they are called with a stack that is always misaligned
20// by 8 bytes with respect to a 16 bytes alignment. This is because they are
21// called immediately after the call to, or immediately before returning from,
22// the function being instrumented. This saves space in the patch point, but
23// misaligns the stack by 8 bytes.
24
25.macro ALIGN_STACK_16B
26#if defined(__APPLE__)
27 subq $$8, %rsp
28#else
29 subq $8, %rsp
30#endif
31 CFI_ADJUST_CFA_OFFSET(8)
32.endm
33
34.macro RESTORE_STACK_ALIGNMENT
35#if defined(__APPLE__)
36 addq $$8, %rsp
37#else
38 addq $8, %rsp
39#endif
40 CFI_ADJUST_CFA_OFFSET(-8)
41.endm
42
43// This macro should keep the stack aligned to 16 bytes.
44.macro SAVE_REGISTERS
45 pushfq
46 CFI_ADJUST_CFA_OFFSET(8)
47 subq $240, %rsp
48 CFI_ADJUST_CFA_OFFSET(240)
49 movq %rbp, 232(%rsp)
50 movupd %xmm0, 216(%rsp)
51 movupd %xmm1, 200(%rsp)
52 movupd %xmm2, 184(%rsp)
53 movupd %xmm3, 168(%rsp)
54 movupd %xmm4, 152(%rsp)
55 movupd %xmm5, 136(%rsp)
56 movupd %xmm6, 120(%rsp)
57 movupd %xmm7, 104(%rsp)
58 movq %rdi, 96(%rsp)
59 movq %rax, 88(%rsp)
60 movq %rdx, 80(%rsp)
61 movq %rsi, 72(%rsp)
62 movq %rcx, 64(%rsp)
63 movq %r8, 56(%rsp)
64 movq %r9, 48(%rsp)
65 movq %r10, 40(%rsp)
66 movq %r11, 32(%rsp)
67 movq %r12, 24(%rsp)
68 movq %r13, 16(%rsp)
69 movq %r14, 8(%rsp)
70 movq %r15, 0(%rsp)
71.endm
72
73// This macro should keep the stack aligned to 16 bytes.
74.macro RESTORE_REGISTERS
75 movq 232(%rsp), %rbp
76 movupd 216(%rsp), %xmm0
77 movupd 200(%rsp), %xmm1
78 movupd 184(%rsp), %xmm2
79 movupd 168(%rsp), %xmm3
80 movupd 152(%rsp), %xmm4
81 movupd 136(%rsp), %xmm5
82 movupd 120(%rsp) , %xmm6
83 movupd 104(%rsp) , %xmm7
84 movq 96(%rsp), %rdi
85 movq 88(%rsp), %rax
86 movq 80(%rsp), %rdx
87 movq 72(%rsp), %rsi
88 movq 64(%rsp), %rcx
89 movq 56(%rsp), %r8
90 movq 48(%rsp), %r9
91 movq 40(%rsp), %r10
92 movq 32(%rsp), %r11
93 movq 24(%rsp), %r12
94 movq 16(%rsp), %r13
95 movq 8(%rsp), %r14
96 movq 0(%rsp), %r15
97 addq $240, %rsp
98 CFI_ADJUST_CFA_OFFSET(-240)
99 popfq
100 CFI_ADJUST_CFA_OFFSET(-8)
101.endm
102
103 .text
104#if !defined(__APPLE__)
105 .section .text
106 .file "xray_trampoline_x86.S"
107#else
108 .section __TEXT,__text
109#endif
110
111//===----------------------------------------------------------------------===//
112
113 .globl ASM_SYMBOL(__xray_FunctionEntry)
114 ASM_HIDDEN(__xray_FunctionEntry)
115 .align 16, 0x90
116 ASM_TYPE_FUNCTION(__xray_FunctionEntry)
117# LLVM-MCA-BEGIN __xray_FunctionEntry
118ASM_SYMBOL(__xray_FunctionEntry):
119 CFI_STARTPROC
120 ALIGN_STACK_16B
121 SAVE_REGISTERS
122
123 // This load has to be atomic, it's concurrent with __xray_patch().
124 // On x86/amd64, a simple (type-aligned) MOV instruction is enough.
125 movq ASM_SYMBOL(_ZN6__xray19XRayPatchedFunctionE)(%rip), %rax
126 testq %rax, %rax
127 je LOCAL_LABEL(tmp0)
128
129 // The patched function prologue puts its xray_instr_map index into %r10d.
130 movl %r10d, %edi
131 xor %esi,%esi
132 callq *%rax
133
134LOCAL_LABEL(tmp0):
135 RESTORE_REGISTERS
136 RESTORE_STACK_ALIGNMENT
137 retq
138# LLVM-MCA-END
139 ASM_SIZE(__xray_FunctionEntry)
140 CFI_ENDPROC
141
142//===----------------------------------------------------------------------===//
143
144 .globl ASM_SYMBOL(__xray_FunctionExit)
145 ASM_HIDDEN(__xray_FunctionExit)
146 .align 16, 0x90
147 ASM_TYPE_FUNCTION(__xray_FunctionExit)
148# LLVM-MCA-BEGIN __xray_FunctionExit
149ASM_SYMBOL(__xray_FunctionExit):
150 CFI_STARTPROC
151 ALIGN_STACK_16B
152
153 // Save the important registers first. Since we're assuming that this
154 // function is only jumped into, we only preserve the registers for
155 // returning.
156 subq $64, %rsp
157 CFI_ADJUST_CFA_OFFSET(64)
158 movq %rbp, 48(%rsp)
159 movupd %xmm0, 32(%rsp)
160 movupd %xmm1, 16(%rsp)
161 movq %rax, 8(%rsp)
162 movq %rdx, 0(%rsp)
163 movq ASM_SYMBOL(_ZN6__xray19XRayPatchedFunctionE)(%rip), %rax
164 testq %rax,%rax
165 je LOCAL_LABEL(tmp2)
166
167 movl %r10d, %edi
168 movl $1, %esi
169 callq *%rax
170
171LOCAL_LABEL(tmp2):
172 // Restore the important registers.
173 movq 48(%rsp), %rbp
174 movupd 32(%rsp), %xmm0
175 movupd 16(%rsp), %xmm1
176 movq 8(%rsp), %rax
177 movq 0(%rsp), %rdx
178 addq $64, %rsp
179 CFI_ADJUST_CFA_OFFSET(-64)
180
181 RESTORE_STACK_ALIGNMENT
182 retq
183# LLVM-MCA-END
184 ASM_SIZE(__xray_FunctionExit)
185 CFI_ENDPROC
186
187//===----------------------------------------------------------------------===//
188
189 .globl ASM_SYMBOL(__xray_FunctionTailExit)
190 ASM_HIDDEN(__xray_FunctionTailExit)
191 .align 16, 0x90
192 ASM_TYPE_FUNCTION(__xray_FunctionTailExit)
193# LLVM-MCA-BEGIN __xray_FunctionTailExit
194ASM_SYMBOL(__xray_FunctionTailExit):
195 CFI_STARTPROC
196 ALIGN_STACK_16B
197 SAVE_REGISTERS
198
199 movq ASM_SYMBOL(_ZN6__xray19XRayPatchedFunctionE)(%rip), %rax
200 testq %rax,%rax
201 je LOCAL_LABEL(tmp4)
202
203 movl %r10d, %edi
204 movl $2, %esi
205 callq *%rax
206
207LOCAL_LABEL(tmp4):
208 RESTORE_REGISTERS
209 RESTORE_STACK_ALIGNMENT
210 retq
211# LLVM-MCA-END
212 ASM_SIZE(__xray_FunctionTailExit)
213 CFI_ENDPROC
214
215//===----------------------------------------------------------------------===//
216
217 .globl ASM_SYMBOL(__xray_ArgLoggerEntry)
218 ASM_HIDDEN(__xray_ArgLoggerEntry)
219 .align 16, 0x90
220 ASM_TYPE_FUNCTION(__xray_ArgLoggerEntry)
221# LLVM-MCA-BEGIN __xray_ArgLoggerEntry
222ASM_SYMBOL(__xray_ArgLoggerEntry):
223 CFI_STARTPROC
224 ALIGN_STACK_16B
225 SAVE_REGISTERS
226
227 // Again, these function pointer loads must be atomic; MOV is fine.
228 movq ASM_SYMBOL(_ZN6__xray13XRayArgLoggerE)(%rip), %rax
229 testq %rax, %rax
230 jne LOCAL_LABEL(arg1entryLog)
231
232 // If [arg1 logging handler] not set, defer to no-arg logging.
233 movq ASM_SYMBOL(_ZN6__xray19XRayPatchedFunctionE)(%rip), %rax
234 testq %rax, %rax
235 je LOCAL_LABEL(arg1entryFail)
236
237LOCAL_LABEL(arg1entryLog):
238
239 // First argument will become the third
240 movq %rdi, %rdx
241
242 // XRayEntryType::LOG_ARGS_ENTRY into the second
243 mov $0x3, %esi
244
245 // 32-bit function ID becomes the first
246 movl %r10d, %edi
247
248 callq *%rax
249
250LOCAL_LABEL(arg1entryFail):
251 RESTORE_REGISTERS
252 RESTORE_STACK_ALIGNMENT
253 retq
254# LLVM-MCA-END
255 ASM_SIZE(__xray_ArgLoggerEntry)
256 CFI_ENDPROC
257
258//===----------------------------------------------------------------------===//
259
260// __xray_*Event have default visibility so that they can be referenced by user
261// DSOs that do not link against the runtime.
262 .global ASM_SYMBOL(__xray_CustomEvent)
263 .align 16, 0x90
264 ASM_TYPE_FUNCTION(__xray_CustomEvent)
265# LLVM-MCA-BEGIN __xray_CustomEvent
266ASM_SYMBOL(__xray_CustomEvent):
267 CFI_STARTPROC
268 SAVE_REGISTERS
269
270 // We take two arguments to this trampoline, which should be in rdi and rsi
271 // already.
272 movq ASM_SYMBOL(_ZN6__xray22XRayPatchedCustomEventE)(%rip), %rax
273 testq %rax,%rax
274 je LOCAL_LABEL(customEventCleanup)
275
276 callq *%rax
277
278LOCAL_LABEL(customEventCleanup):
279 RESTORE_REGISTERS
280 retq
281# LLVM-MCA-END
282 ASM_SIZE(__xray_CustomEvent)
283 CFI_ENDPROC
284
285//===----------------------------------------------------------------------===//
286
287 .global ASM_SYMBOL(__xray_TypedEvent)
288 .align 16, 0x90
289 ASM_TYPE_FUNCTION(__xray_TypedEvent)
290# LLVM-MCA-BEGIN __xray_TypedEvent
291ASM_SYMBOL(__xray_TypedEvent):
292 CFI_STARTPROC
293 SAVE_REGISTERS
294
295 // We pass three arguments to this trampoline, which should be in rdi, rsi
296 // and rdx without our intervention.
297 movq ASM_SYMBOL(_ZN6__xray21XRayPatchedTypedEventE)(%rip), %rax
298 testq %rax,%rax
299 je LOCAL_LABEL(typedEventCleanup)
300
301 callq *%rax
302
303LOCAL_LABEL(typedEventCleanup):
304 RESTORE_REGISTERS
305 retq
306# LLVM-MCA-END
307 ASM_SIZE(__xray_TypedEvent)
308 CFI_ENDPROC
309
310//===----------------------------------------------------------------------===//
311
312NO_EXEC_STACK_DIRECTIVE
313

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source code of compiler-rt/lib/xray/xray_trampoline_x86_64.S