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1 //===------------- OrcABISupport.cpp - ABI specific support code ----------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/ExecutionEngine/Orc/OrcABISupport.h"
11 #include "llvm/Support/Process.h"
12 
13 namespace llvm {
14 namespace orc {
15 
writeResolverCode(uint8_t * ResolverMem,JITReentryFn ReentryFn,void * CallbackMgr)16 void OrcAArch64::writeResolverCode(uint8_t *ResolverMem, JITReentryFn ReentryFn,
17                                    void *CallbackMgr) {
18 
19   const uint32_t ResolverCode[] = {
20     // resolver_entry:
21     0xa9bf47fd,        // 0x000:  stp  x29, x17, [sp, #-16]!
22     0x910003fd,        // 0x004:  mov  x29, sp
23     0xa9bf73fb,        // 0x008:  stp  x27, x28, [sp, #-16]!
24     0xa9bf6bf9,        // 0x00c:  stp  x25, x26, [sp, #-16]!
25     0xa9bf63f7,        // 0x010:  stp  x23, x24, [sp, #-16]!
26     0xa9bf5bf5,        // 0x014:  stp  x21, x22, [sp, #-16]!
27     0xa9bf53f3,        // 0x018:  stp  x19, x20, [sp, #-16]!
28     0xa9bf3fee,        // 0x01c:  stp  x14, x15, [sp, #-16]!
29     0xa9bf37ec,        // 0x020:  stp  x12, x13, [sp, #-16]!
30     0xa9bf2fea,        // 0x024:  stp  x10, x11, [sp, #-16]!
31     0xa9bf27e8,        // 0x028:  stp   x8,  x9, [sp, #-16]!
32     0xa9bf1fe6,        // 0x02c:  stp   x6,  x7, [sp, #-16]!
33     0xa9bf17e4,        // 0x030:  stp   x4,  x5, [sp, #-16]!
34     0xa9bf0fe2,        // 0x034:  stp   x2,  x3, [sp, #-16]!
35     0xa9bf07e0,        // 0x038:  stp   x0,  x1, [sp, #-16]!
36     0xadbf7ffe,        // 0x03c:  stp  q30, q31, [sp, #-32]!
37     0xadbf77fc,        // 0x040:  stp  q28, q29, [sp, #-32]!
38     0xadbf6ffa,        // 0x044:  stp  q26, q27, [sp, #-32]!
39     0xadbf67f8,        // 0x048:  stp  q24, q25, [sp, #-32]!
40     0xadbf5ff6,        // 0x04c:  stp  q22, q23, [sp, #-32]!
41     0xadbf57f4,        // 0x050:  stp  q20, q21, [sp, #-32]!
42     0xadbf4ff2,        // 0x054:  stp  q18, q19, [sp, #-32]!
43     0xadbf47f0,        // 0x058:  stp  q16, q17, [sp, #-32]!
44     0xadbf3fee,        // 0x05c:  stp  q14, q15, [sp, #-32]!
45     0xadbf37ec,        // 0x060:  stp  q12, q13, [sp, #-32]!
46     0xadbf2fea,        // 0x064:  stp  q10, q11, [sp, #-32]!
47     0xadbf27e8,        // 0x068:  stp   q8,  q9, [sp, #-32]!
48     0xadbf1fe6,        // 0x06c:  stp   q6,  q7, [sp, #-32]!
49     0xadbf17e4,        // 0x070:  stp   q4,  q5, [sp, #-32]!
50     0xadbf0fe2,        // 0x074:  stp   q2,  q3, [sp, #-32]!
51     0xadbf07e0,        // 0x078:  stp   q0,  q1, [sp, #-32]!
52     0x580004e0,        // 0x07c:  ldr   x0, Lcallbackmgr
53     0xaa1e03e1,        // 0x080:  mov   x1, x30
54     0xd1003021,        // 0x084:  sub   x1,  x1, #12
55     0x58000442,        // 0x088:  ldr   x2, Lreentry_fn_ptr
56     0xd63f0040,        // 0x08c:  blr   x2
57     0xaa0003f1,        // 0x090:  mov   x17, x0
58     0xacc107e0,        // 0x094:  ldp   q0,  q1, [sp], #32
59     0xacc10fe2,        // 0x098:  ldp   q2,  q3, [sp], #32
60     0xacc117e4,        // 0x09c:  ldp   q4,  q5, [sp], #32
61     0xacc11fe6,        // 0x0a0:  ldp   q6,  q7, [sp], #32
62     0xacc127e8,        // 0x0a4:  ldp   q8,  q9, [sp], #32
63     0xacc12fea,        // 0x0a8:  ldp  q10, q11, [sp], #32
64     0xacc137ec,        // 0x0ac:  ldp  q12, q13, [sp], #32
65     0xacc13fee,        // 0x0b0:  ldp  q14, q15, [sp], #32
66     0xacc147f0,        // 0x0b4:  ldp  q16, q17, [sp], #32
67     0xacc14ff2,        // 0x0b8:  ldp  q18, q19, [sp], #32
68     0xacc157f4,        // 0x0bc:  ldp  q20, q21, [sp], #32
69     0xacc15ff6,        // 0x0c0:  ldp  q22, q23, [sp], #32
70     0xacc167f8,        // 0x0c4:  ldp  q24, q25, [sp], #32
71     0xacc16ffa,        // 0x0c8:  ldp  q26, q27, [sp], #32
72     0xacc177fc,        // 0x0cc:  ldp  q28, q29, [sp], #32
73     0xacc17ffe,        // 0x0d0:  ldp  q30, q31, [sp], #32
74     0xa8c107e0,        // 0x0d4:  ldp   x0,  x1, [sp], #16
75     0xa8c10fe2,        // 0x0d8:  ldp   x2,  x3, [sp], #16
76     0xa8c117e4,        // 0x0dc:  ldp   x4,  x5, [sp], #16
77     0xa8c11fe6,        // 0x0e0:  ldp   x6,  x7, [sp], #16
78     0xa8c127e8,        // 0x0e4:  ldp   x8,  x9, [sp], #16
79     0xa8c12fea,        // 0x0e8:  ldp  x10, x11, [sp], #16
80     0xa8c137ec,        // 0x0ec:  ldp  x12, x13, [sp], #16
81     0xa8c13fee,        // 0x0f0:  ldp  x14, x15, [sp], #16
82     0xa8c153f3,        // 0x0f4:  ldp  x19, x20, [sp], #16
83     0xa8c15bf5,        // 0x0f8:  ldp  x21, x22, [sp], #16
84     0xa8c163f7,        // 0x0fc:  ldp  x23, x24, [sp], #16
85     0xa8c16bf9,        // 0x100:  ldp  x25, x26, [sp], #16
86     0xa8c173fb,        // 0x104:  ldp  x27, x28, [sp], #16
87     0xa8c17bfd,        // 0x108:  ldp  x29, x30, [sp], #16
88     0xd65f0220,        // 0x10c:  ret  x17
89     0x01234567,        // 0x110:  Lreentry_fn_ptr:
90     0xdeadbeef,        // 0x114:      .quad 0
91     0x98765432,        // 0x118:  Lcallbackmgr:
92     0xcafef00d         // 0x11c:      .quad 0
93   };
94 
95   const unsigned ReentryFnAddrOffset = 0x110;
96   const unsigned CallbackMgrAddrOffset = 0x118;
97 
98   memcpy(ResolverMem, ResolverCode, sizeof(ResolverCode));
99   memcpy(ResolverMem + ReentryFnAddrOffset, &ReentryFn, sizeof(ReentryFn));
100   memcpy(ResolverMem + CallbackMgrAddrOffset, &CallbackMgr,
101          sizeof(CallbackMgr));
102 }
103 
writeTrampolines(uint8_t * TrampolineMem,void * ResolverAddr,unsigned NumTrampolines)104 void OrcAArch64::writeTrampolines(uint8_t *TrampolineMem, void *ResolverAddr,
105                                   unsigned NumTrampolines) {
106 
107   unsigned OffsetToPtr = alignTo(NumTrampolines * TrampolineSize, 8);
108 
109   memcpy(TrampolineMem + OffsetToPtr, &ResolverAddr, sizeof(void *));
110 
111   // OffsetToPtr is actually the offset from the PC for the 2nd instruction, so
112   // subtract 32-bits.
113   OffsetToPtr -= 4;
114 
115   uint32_t *Trampolines = reinterpret_cast<uint32_t *>(TrampolineMem);
116 
117   for (unsigned I = 0; I < NumTrampolines; ++I, OffsetToPtr -= TrampolineSize) {
118     Trampolines[3 * I + 0] = 0xaa1e03f1;                      // mov x17, x30
119     Trampolines[3 * I + 1] = 0x58000010 | (OffsetToPtr << 3); // adr x16, Lptr
120     Trampolines[3 * I + 2] = 0xd63f0200;                      // blr x16
121   }
122 
123 }
124 
emitIndirectStubsBlock(IndirectStubsInfo & StubsInfo,unsigned MinStubs,void * InitialPtrVal)125 Error OrcAArch64::emitIndirectStubsBlock(IndirectStubsInfo &StubsInfo,
126                                          unsigned MinStubs,
127                                          void *InitialPtrVal) {
128   // Stub format is:
129   //
130   // .section __orc_stubs
131   // stub1:
132   //                 ldr     x0, ptr1       ; PC-rel load of ptr1
133   //                 br      x0             ; Jump to resolver
134   // stub2:
135   //                 ldr     x0, ptr2       ; PC-rel load of ptr2
136   //                 br      x0             ; Jump to resolver
137   //
138   // ...
139   //
140   // .section __orc_ptrs
141   // ptr1:
142   //                 .quad 0x0
143   // ptr2:
144   //                 .quad 0x0
145   //
146   // ...
147 
148   const unsigned StubSize = IndirectStubsInfo::StubSize;
149 
150   // Emit at least MinStubs, rounded up to fill the pages allocated.
151   unsigned PageSize = sys::Process::getPageSize();
152   unsigned NumPages = ((MinStubs * StubSize) + (PageSize - 1)) / PageSize;
153   unsigned NumStubs = (NumPages * PageSize) / StubSize;
154 
155   // Allocate memory for stubs and pointers in one call.
156   std::error_code EC;
157   auto StubsMem = sys::OwningMemoryBlock(sys::Memory::allocateMappedMemory(
158       2 * NumPages * PageSize, nullptr,
159       sys::Memory::MF_READ | sys::Memory::MF_WRITE, EC));
160 
161   if (EC)
162     return errorCodeToError(EC);
163 
164   // Create separate MemoryBlocks representing the stubs and pointers.
165   sys::MemoryBlock StubsBlock(StubsMem.base(), NumPages * PageSize);
166   sys::MemoryBlock PtrsBlock(static_cast<char *>(StubsMem.base()) +
167                                  NumPages * PageSize,
168                              NumPages * PageSize);
169 
170   // Populate the stubs page stubs and mark it executable.
171   uint64_t *Stub = reinterpret_cast<uint64_t *>(StubsBlock.base());
172   uint64_t PtrOffsetField = static_cast<uint64_t>(NumPages * PageSize)
173                             << 3;
174 
175   for (unsigned I = 0; I < NumStubs; ++I)
176     Stub[I] = 0xd61f020058000010 | PtrOffsetField;
177 
178   if (auto EC = sys::Memory::protectMappedMemory(
179           StubsBlock, sys::Memory::MF_READ | sys::Memory::MF_EXEC))
180     return errorCodeToError(EC);
181 
182   // Initialize all pointers to point at FailureAddress.
183   void **Ptr = reinterpret_cast<void **>(PtrsBlock.base());
184   for (unsigned I = 0; I < NumStubs; ++I)
185     Ptr[I] = InitialPtrVal;
186 
187   StubsInfo = IndirectStubsInfo(NumStubs, std::move(StubsMem));
188 
189   return Error::success();
190 }
191 
writeTrampolines(uint8_t * TrampolineMem,void * ResolverAddr,unsigned NumTrampolines)192 void OrcX86_64_Base::writeTrampolines(uint8_t *TrampolineMem,
193                                       void *ResolverAddr,
194                                       unsigned NumTrampolines) {
195 
196   unsigned OffsetToPtr = NumTrampolines * TrampolineSize;
197 
198   memcpy(TrampolineMem + OffsetToPtr, &ResolverAddr, sizeof(void *));
199 
200   uint64_t *Trampolines = reinterpret_cast<uint64_t *>(TrampolineMem);
201   uint64_t CallIndirPCRel = 0xf1c40000000015ff;
202 
203   for (unsigned I = 0; I < NumTrampolines; ++I, OffsetToPtr -= TrampolineSize)
204     Trampolines[I] = CallIndirPCRel | ((OffsetToPtr - 6) << 16);
205 }
206 
emitIndirectStubsBlock(IndirectStubsInfo & StubsInfo,unsigned MinStubs,void * InitialPtrVal)207 Error OrcX86_64_Base::emitIndirectStubsBlock(IndirectStubsInfo &StubsInfo,
208                                              unsigned MinStubs,
209                                              void *InitialPtrVal) {
210   // Stub format is:
211   //
212   // .section __orc_stubs
213   // stub1:
214   //                 jmpq    *ptr1(%rip)
215   //                 .byte   0xC4         ; <- Invalid opcode padding.
216   //                 .byte   0xF1
217   // stub2:
218   //                 jmpq    *ptr2(%rip)
219   //
220   // ...
221   //
222   // .section __orc_ptrs
223   // ptr1:
224   //                 .quad 0x0
225   // ptr2:
226   //                 .quad 0x0
227   //
228   // ...
229 
230   const unsigned StubSize = IndirectStubsInfo::StubSize;
231 
232   // Emit at least MinStubs, rounded up to fill the pages allocated.
233   unsigned PageSize = sys::Process::getPageSize();
234   unsigned NumPages = ((MinStubs * StubSize) + (PageSize - 1)) / PageSize;
235   unsigned NumStubs = (NumPages * PageSize) / StubSize;
236 
237   // Allocate memory for stubs and pointers in one call.
238   std::error_code EC;
239   auto StubsMem = sys::OwningMemoryBlock(sys::Memory::allocateMappedMemory(
240       2 * NumPages * PageSize, nullptr,
241       sys::Memory::MF_READ | sys::Memory::MF_WRITE, EC));
242 
243   if (EC)
244     return errorCodeToError(EC);
245 
246   // Create separate MemoryBlocks representing the stubs and pointers.
247   sys::MemoryBlock StubsBlock(StubsMem.base(), NumPages * PageSize);
248   sys::MemoryBlock PtrsBlock(static_cast<char *>(StubsMem.base()) +
249                                  NumPages * PageSize,
250                              NumPages * PageSize);
251 
252   // Populate the stubs page stubs and mark it executable.
253   uint64_t *Stub = reinterpret_cast<uint64_t *>(StubsBlock.base());
254   uint64_t PtrOffsetField = static_cast<uint64_t>(NumPages * PageSize - 6)
255                             << 16;
256   for (unsigned I = 0; I < NumStubs; ++I)
257     Stub[I] = 0xF1C40000000025ff | PtrOffsetField;
258 
259   if (auto EC = sys::Memory::protectMappedMemory(
260           StubsBlock, sys::Memory::MF_READ | sys::Memory::MF_EXEC))
261     return errorCodeToError(EC);
262 
263   // Initialize all pointers to point at FailureAddress.
264   void **Ptr = reinterpret_cast<void **>(PtrsBlock.base());
265   for (unsigned I = 0; I < NumStubs; ++I)
266     Ptr[I] = InitialPtrVal;
267 
268   StubsInfo = IndirectStubsInfo(NumStubs, std::move(StubsMem));
269 
270   return Error::success();
271 }
272 
writeResolverCode(uint8_t * ResolverMem,JITReentryFn ReentryFn,void * CallbackMgr)273 void OrcX86_64_SysV::writeResolverCode(uint8_t *ResolverMem,
274                                        JITReentryFn ReentryFn,
275                                        void *CallbackMgr) {
276 
277   const uint8_t ResolverCode[] = {
278       // resolver_entry:
279       0x55,                                     // 0x00: pushq     %rbp
280       0x48, 0x89, 0xe5,                         // 0x01: movq      %rsp, %rbp
281       0x50,                                     // 0x04: pushq     %rax
282       0x53,                                     // 0x05: pushq     %rbx
283       0x51,                                     // 0x06: pushq     %rcx
284       0x52,                                     // 0x07: pushq     %rdx
285       0x56,                                     // 0x08: pushq     %rsi
286       0x57,                                     // 0x09: pushq     %rdi
287       0x41, 0x50,                               // 0x0a: pushq     %r8
288       0x41, 0x51,                               // 0x0c: pushq     %r9
289       0x41, 0x52,                               // 0x0e: pushq     %r10
290       0x41, 0x53,                               // 0x10: pushq     %r11
291       0x41, 0x54,                               // 0x12: pushq     %r12
292       0x41, 0x55,                               // 0x14: pushq     %r13
293       0x41, 0x56,                               // 0x16: pushq     %r14
294       0x41, 0x57,                               // 0x18: pushq     %r15
295       0x48, 0x81, 0xec, 0x08, 0x02, 0x00, 0x00, // 0x1a: subq      0x208, %rsp
296       0x48, 0x0f, 0xae, 0x04, 0x24,             // 0x21: fxsave64  (%rsp)
297       0x48, 0xbf,                               // 0x26: movabsq   <CBMgr>, %rdi
298 
299       // 0x28: Callback manager addr.
300       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
301 
302       0x48, 0x8b, 0x75, 0x08,                   // 0x30: movq      8(%rbp), %rsi
303       0x48, 0x83, 0xee, 0x06,                   // 0x34: subq      $6, %rsi
304       0x48, 0xb8,                               // 0x38: movabsq   <REntry>, %rax
305 
306       // 0x3a: JIT re-entry fn addr:
307       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
308 
309       0xff, 0xd0,                               // 0x42: callq     *%rax
310       0x48, 0x89, 0x45, 0x08,                   // 0x44: movq      %rax, 8(%rbp)
311       0x48, 0x0f, 0xae, 0x0c, 0x24,             // 0x48: fxrstor64 (%rsp)
312       0x48, 0x81, 0xc4, 0x08, 0x02, 0x00, 0x00, // 0x4d: addq      0x208, %rsp
313       0x41, 0x5f,                               // 0x54: popq      %r15
314       0x41, 0x5e,                               // 0x56: popq      %r14
315       0x41, 0x5d,                               // 0x58: popq      %r13
316       0x41, 0x5c,                               // 0x5a: popq      %r12
317       0x41, 0x5b,                               // 0x5c: popq      %r11
318       0x41, 0x5a,                               // 0x5e: popq      %r10
319       0x41, 0x59,                               // 0x60: popq      %r9
320       0x41, 0x58,                               // 0x62: popq      %r8
321       0x5f,                                     // 0x64: popq      %rdi
322       0x5e,                                     // 0x65: popq      %rsi
323       0x5a,                                     // 0x66: popq      %rdx
324       0x59,                                     // 0x67: popq      %rcx
325       0x5b,                                     // 0x68: popq      %rbx
326       0x58,                                     // 0x69: popq      %rax
327       0x5d,                                     // 0x6a: popq      %rbp
328       0xc3,                                     // 0x6b: retq
329   };
330 
331   const unsigned ReentryFnAddrOffset = 0x3a;
332   const unsigned CallbackMgrAddrOffset = 0x28;
333 
334   memcpy(ResolverMem, ResolverCode, sizeof(ResolverCode));
335   memcpy(ResolverMem + ReentryFnAddrOffset, &ReentryFn, sizeof(ReentryFn));
336   memcpy(ResolverMem + CallbackMgrAddrOffset, &CallbackMgr,
337          sizeof(CallbackMgr));
338 }
339 
writeResolverCode(uint8_t * ResolverMem,JITReentryFn ReentryFn,void * CallbackMgr)340 void OrcX86_64_Win32::writeResolverCode(uint8_t *ResolverMem,
341                                         JITReentryFn ReentryFn,
342                                         void *CallbackMgr) {
343 
344   // resolverCode is similar to OrcX86_64 with differences specific to windows x64 calling convention:
345   // arguments go into rcx, rdx and come in reverse order, shadow space allocation on stack
346   const uint8_t ResolverCode[] = {
347       // resolver_entry:
348       0x55,                                      // 0x00: pushq     %rbp
349       0x48, 0x89, 0xe5,                          // 0x01: movq      %rsp, %rbp
350       0x50,                                      // 0x04: pushq     %rax
351       0x53,                                      // 0x05: pushq     %rbx
352       0x51,                                      // 0x06: pushq     %rcx
353       0x52,                                      // 0x07: pushq     %rdx
354       0x56,                                      // 0x08: pushq     %rsi
355       0x57,                                      // 0x09: pushq     %rdi
356       0x41, 0x50,                                // 0x0a: pushq     %r8
357       0x41, 0x51,                                // 0x0c: pushq     %r9
358       0x41, 0x52,                                // 0x0e: pushq     %r10
359       0x41, 0x53,                                // 0x10: pushq     %r11
360       0x41, 0x54,                                // 0x12: pushq     %r12
361       0x41, 0x55,                                // 0x14: pushq     %r13
362       0x41, 0x56,                                // 0x16: pushq     %r14
363       0x41, 0x57,                                // 0x18: pushq     %r15
364       0x48, 0x81, 0xec, 0x08, 0x02, 0x00, 0x00,  // 0x1a: subq      0x208, %rsp
365       0x48, 0x0f, 0xae, 0x04, 0x24,              // 0x21: fxsave64  (%rsp)
366 
367       0x48, 0xb9,                                // 0x26: movabsq   <CBMgr>, %rcx
368       // 0x28: Callback manager addr.
369       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
370 
371       0x48, 0x8B, 0x55, 0x08,                    // 0x30: mov       rdx, [rbp+0x8]
372       0x48, 0x83, 0xea, 0x06,                    // 0x34: sub       rdx, 0x6
373 
374       0x48, 0xb8,                                // 0x38: movabsq   <REntry>, %rax
375       // 0x3a: JIT re-entry fn addr:
376       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
377 
378       // 0x42: sub       rsp, 0x20 (Allocate shadow space)
379       0x48, 0x83, 0xEC, 0x20,
380       0xff, 0xd0,                                // 0x46: callq     *%rax
381 
382       // 0x48: add       rsp, 0x20 (Free shadow space)
383       0x48, 0x83, 0xC4, 0x20,
384 
385       0x48, 0x89, 0x45, 0x08,                    // 0x4C: movq      %rax, 8(%rbp)
386       0x48, 0x0f, 0xae, 0x0c, 0x24,              // 0x50: fxrstor64 (%rsp)
387       0x48, 0x81, 0xc4, 0x08, 0x02, 0x00, 0x00,  // 0x55: addq      0x208, %rsp
388       0x41, 0x5f,                                // 0x5C: popq      %r15
389       0x41, 0x5e,                                // 0x5E: popq      %r14
390       0x41, 0x5d,                                // 0x60: popq      %r13
391       0x41, 0x5c,                                // 0x62: popq      %r12
392       0x41, 0x5b,                                // 0x64: popq      %r11
393       0x41, 0x5a,                                // 0x66: popq      %r10
394       0x41, 0x59,                                // 0x68: popq      %r9
395       0x41, 0x58,                                // 0x6a: popq      %r8
396       0x5f,                                      // 0x6c: popq      %rdi
397       0x5e,                                      // 0x6d: popq      %rsi
398       0x5a,                                      // 0x6e: popq      %rdx
399       0x59,                                      // 0x6f: popq      %rcx
400       0x5b,                                      // 0x70: popq      %rbx
401       0x58,                                      // 0x71: popq      %rax
402       0x5d,                                      // 0x72: popq      %rbp
403       0xc3,                                      // 0x73: retq
404   };
405 
406 
407   const unsigned ReentryFnAddrOffset = 0x3a;
408   const unsigned CallbackMgrAddrOffset = 0x28;
409 
410   memcpy(ResolverMem, ResolverCode, sizeof(ResolverCode));
411   memcpy(ResolverMem + ReentryFnAddrOffset, &ReentryFn, sizeof(ReentryFn));
412   memcpy(ResolverMem + CallbackMgrAddrOffset, &CallbackMgr,
413          sizeof(CallbackMgr));
414 }
415 
writeResolverCode(uint8_t * ResolverMem,JITReentryFn ReentryFn,void * CallbackMgr)416 void OrcI386::writeResolverCode(uint8_t *ResolverMem, JITReentryFn ReentryFn,
417                                 void *CallbackMgr) {
418 
419   const uint8_t ResolverCode[] = {
420       // resolver_entry:
421       0x55,                               // 0x00: pushl    %ebp
422       0x89, 0xe5,                         // 0x01: movl     %esp, %ebp
423       0x54,                               // 0x03: pushl    %esp
424       0x83, 0xe4, 0xf0,                   // 0x04: andl     $-0x10, %esp
425       0x50,                               // 0x07: pushl    %eax
426       0x53,                               // 0x08: pushl    %ebx
427       0x51,                               // 0x09: pushl    %ecx
428       0x52,                               // 0x0a: pushl    %edx
429       0x56,                               // 0x0b: pushl    %esi
430       0x57,                               // 0x0c: pushl    %edi
431       0x81, 0xec, 0x18, 0x02, 0x00, 0x00, // 0x0d: subl     $0x218, %esp
432       0x0f, 0xae, 0x44, 0x24, 0x10,       // 0x13: fxsave   0x10(%esp)
433       0x8b, 0x75, 0x04,                   // 0x18: movl     0x4(%ebp), %esi
434       0x83, 0xee, 0x05,                   // 0x1b: subl     $0x5, %esi
435       0x89, 0x74, 0x24, 0x04,             // 0x1e: movl     %esi, 0x4(%esp)
436       0xc7, 0x04, 0x24, 0x00, 0x00, 0x00,
437       0x00,                               // 0x22: movl     <cbmgr>, (%esp)
438       0xb8, 0x00, 0x00, 0x00, 0x00,       // 0x29: movl     <reentry>, %eax
439       0xff, 0xd0,                         // 0x2e: calll    *%eax
440       0x89, 0x45, 0x04,                   // 0x30: movl     %eax, 0x4(%ebp)
441       0x0f, 0xae, 0x4c, 0x24, 0x10,       // 0x33: fxrstor  0x10(%esp)
442       0x81, 0xc4, 0x18, 0x02, 0x00, 0x00, // 0x38: addl     $0x218, %esp
443       0x5f,                               // 0x3e: popl     %edi
444       0x5e,                               // 0x3f: popl     %esi
445       0x5a,                               // 0x40: popl     %edx
446       0x59,                               // 0x41: popl     %ecx
447       0x5b,                               // 0x42: popl     %ebx
448       0x58,                               // 0x43: popl     %eax
449       0x8b, 0x65, 0xfc,                   // 0x44: movl     -0x4(%ebp), %esp
450       0x5d,                               // 0x48: popl     %ebp
451       0xc3                                // 0x49: retl
452   };
453 
454   const unsigned ReentryFnAddrOffset = 0x2a;
455   const unsigned CallbackMgrAddrOffset = 0x25;
456 
457   memcpy(ResolverMem, ResolverCode, sizeof(ResolverCode));
458   memcpy(ResolverMem + ReentryFnAddrOffset, &ReentryFn, sizeof(ReentryFn));
459   memcpy(ResolverMem + CallbackMgrAddrOffset, &CallbackMgr,
460          sizeof(CallbackMgr));
461 }
462 
writeTrampolines(uint8_t * TrampolineMem,void * ResolverAddr,unsigned NumTrampolines)463 void OrcI386::writeTrampolines(uint8_t *TrampolineMem, void *ResolverAddr,
464                                unsigned NumTrampolines) {
465 
466   uint64_t CallRelImm = 0xF1C4C400000000e8;
467   uint64_t Resolver = reinterpret_cast<uint64_t>(ResolverAddr);
468   uint64_t ResolverRel =
469       Resolver - reinterpret_cast<uint64_t>(TrampolineMem) - 5;
470 
471   uint64_t *Trampolines = reinterpret_cast<uint64_t *>(TrampolineMem);
472   for (unsigned I = 0; I < NumTrampolines; ++I, ResolverRel -= TrampolineSize)
473     Trampolines[I] = CallRelImm | (ResolverRel << 8);
474 }
475 
emitIndirectStubsBlock(IndirectStubsInfo & StubsInfo,unsigned MinStubs,void * InitialPtrVal)476 Error OrcI386::emitIndirectStubsBlock(IndirectStubsInfo &StubsInfo,
477                                       unsigned MinStubs, void *InitialPtrVal) {
478   // Stub format is:
479   //
480   // .section __orc_stubs
481   // stub1:
482   //                 jmpq    *ptr1
483   //                 .byte   0xC4         ; <- Invalid opcode padding.
484   //                 .byte   0xF1
485   // stub2:
486   //                 jmpq    *ptr2
487   //
488   // ...
489   //
490   // .section __orc_ptrs
491   // ptr1:
492   //                 .quad 0x0
493   // ptr2:
494   //                 .quad 0x0
495   //
496   // ...
497 
498   const unsigned StubSize = IndirectStubsInfo::StubSize;
499 
500   // Emit at least MinStubs, rounded up to fill the pages allocated.
501   unsigned PageSize = sys::Process::getPageSize();
502   unsigned NumPages = ((MinStubs * StubSize) + (PageSize - 1)) / PageSize;
503   unsigned NumStubs = (NumPages * PageSize) / StubSize;
504 
505   // Allocate memory for stubs and pointers in one call.
506   std::error_code EC;
507   auto StubsMem = sys::OwningMemoryBlock(sys::Memory::allocateMappedMemory(
508       2 * NumPages * PageSize, nullptr,
509       sys::Memory::MF_READ | sys::Memory::MF_WRITE, EC));
510 
511   if (EC)
512     return errorCodeToError(EC);
513 
514   // Create separate MemoryBlocks representing the stubs and pointers.
515   sys::MemoryBlock StubsBlock(StubsMem.base(), NumPages * PageSize);
516   sys::MemoryBlock PtrsBlock(static_cast<char *>(StubsMem.base()) +
517                                  NumPages * PageSize,
518                              NumPages * PageSize);
519 
520   // Populate the stubs page stubs and mark it executable.
521   uint64_t *Stub = reinterpret_cast<uint64_t *>(StubsBlock.base());
522   uint64_t PtrAddr = reinterpret_cast<uint64_t>(PtrsBlock.base());
523   for (unsigned I = 0; I < NumStubs; ++I, PtrAddr += 4)
524     Stub[I] = 0xF1C40000000025ff | (PtrAddr << 16);
525 
526   if (auto EC = sys::Memory::protectMappedMemory(
527           StubsBlock, sys::Memory::MF_READ | sys::Memory::MF_EXEC))
528     return errorCodeToError(EC);
529 
530   // Initialize all pointers to point at FailureAddress.
531   void **Ptr = reinterpret_cast<void **>(PtrsBlock.base());
532   for (unsigned I = 0; I < NumStubs; ++I)
533     Ptr[I] = InitialPtrVal;
534 
535   StubsInfo = IndirectStubsInfo(NumStubs, std::move(StubsMem));
536 
537   return Error::success();
538 }
539 
540 } // End namespace orc.
541 } // End namespace llvm.
542