Mercurial > hg > truffle
annotate src/cpu/x86/vm/nativeInst_x86.cpp @ 10408:836a62f43af9
Merge with http://hg.openjdk.java.net/hsx/hsx25/hotspot/
| author | Doug Simon <doug.simon@oracle.com> |
|---|---|
| date | Wed, 19 Jun 2013 10:45:56 +0200 |
| parents | cd3d6a6b95d9 |
| children | 78c808233ff1 78bbf4d43a14 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 1972 | 2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. |
| 0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 * | |
| 5 * This code is free software; you can redistribute it and/or modify it | |
| 6 * under the terms of the GNU General Public License version 2 only, as | |
| 7 * published by the Free Software Foundation. | |
| 8 * | |
| 9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 12 * version 2 for more details (a copy is included in the LICENSE file that | |
| 13 * accompanied this code). | |
| 14 * | |
| 15 * You should have received a copy of the GNU General Public License version | |
| 16 * 2 along with this work; if not, write to the Free Software Foundation, | |
| 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 18 * | |
|
1552
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
304
diff
changeset
|
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
|
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
304
diff
changeset
|
20 * or visit www.oracle.com if you need additional information or have any |
|
c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
304
diff
changeset
|
21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 1972 | 25 #include "precompiled.hpp" |
|
7199
cd3d6a6b95d9
8003240: x86: move MacroAssembler into separate file
twisti
parents:
4759
diff
changeset
|
26 #include "asm/macroAssembler.hpp" |
| 1972 | 27 #include "memory/resourceArea.hpp" |
| 28 #include "nativeInst_x86.hpp" | |
| 29 #include "oops/oop.inline.hpp" | |
| 30 #include "runtime/handles.hpp" | |
| 31 #include "runtime/sharedRuntime.hpp" | |
| 32 #include "runtime/stubRoutines.hpp" | |
| 33 #include "utilities/ostream.hpp" | |
| 34 #ifdef COMPILER1 | |
| 35 #include "c1/c1_Runtime1.hpp" | |
| 36 #endif | |
| 0 | 37 |
| 38 void NativeInstruction::wrote(int offset) { | |
| 39 ICache::invalidate_word(addr_at(offset)); | |
| 40 } | |
| 41 | |
| 42 | |
| 43 void NativeCall::verify() { | |
| 44 // Make sure code pattern is actually a call imm32 instruction. | |
| 45 int inst = ubyte_at(0); | |
| 46 if (inst != instruction_code) { | |
| 47 tty->print_cr("Addr: " INTPTR_FORMAT " Code: 0x%x", instruction_address(), | |
| 48 inst); | |
| 49 fatal("not a call disp32"); | |
| 50 } | |
| 51 } | |
| 52 | |
| 53 address NativeCall::destination() const { | |
| 54 // Getting the destination of a call isn't safe because that call can | |
| 55 // be getting patched while you're calling this. There's only special | |
| 56 // places where this can be called but not automatically verifiable by | |
| 57 // checking which locks are held. The solution is true atomic patching | |
| 58 // on x86, nyi. | |
| 59 return return_address() + displacement(); | |
| 60 } | |
| 61 | |
| 62 void NativeCall::print() { | |
| 63 tty->print_cr(PTR_FORMAT ": call " PTR_FORMAT, | |
| 64 instruction_address(), destination()); | |
| 65 } | |
| 66 | |
| 67 // Inserts a native call instruction at a given pc | |
| 68 void NativeCall::insert(address code_pos, address entry) { | |
| 69 intptr_t disp = (intptr_t)entry - ((intptr_t)code_pos + 1 + 4); | |
| 70 #ifdef AMD64 | |
| 71 guarantee(disp == (intptr_t)(jint)disp, "must be 32-bit offset"); | |
| 72 #endif // AMD64 | |
| 73 *code_pos = instruction_code; | |
| 74 *((int32_t *)(code_pos+1)) = (int32_t) disp; | |
| 75 ICache::invalidate_range(code_pos, instruction_size); | |
| 76 } | |
| 77 | |
| 78 // MT-safe patching of a call instruction. | |
| 79 // First patches first word of instruction to two jmp's that jmps to them | |
| 80 // selfs (spinlock). Then patches the last byte, and then atomicly replaces | |
| 81 // the jmp's with the first 4 byte of the new instruction. | |
| 82 void NativeCall::replace_mt_safe(address instr_addr, address code_buffer) { | |
| 83 assert(Patching_lock->is_locked() || | |
| 84 SafepointSynchronize::is_at_safepoint(), "concurrent code patching"); | |
| 85 assert (instr_addr != NULL, "illegal address for code patching"); | |
| 86 | |
| 87 NativeCall* n_call = nativeCall_at (instr_addr); // checking that it is a call | |
| 88 if (os::is_MP()) { | |
| 89 guarantee((intptr_t)instr_addr % BytesPerWord == 0, "must be aligned"); | |
| 90 } | |
| 91 | |
| 92 // First patch dummy jmp in place | |
| 93 unsigned char patch[4]; | |
| 94 assert(sizeof(patch)==sizeof(jint), "sanity check"); | |
| 95 patch[0] = 0xEB; // jmp rel8 | |
| 96 patch[1] = 0xFE; // jmp to self | |
| 97 patch[2] = 0xEB; | |
| 98 patch[3] = 0xFE; | |
| 99 | |
| 100 // First patch dummy jmp in place | |
| 101 *(jint*)instr_addr = *(jint *)patch; | |
| 102 | |
| 103 // Invalidate. Opteron requires a flush after every write. | |
| 104 n_call->wrote(0); | |
| 105 | |
| 106 // Patch 4th byte | |
| 107 instr_addr[4] = code_buffer[4]; | |
| 108 | |
| 109 n_call->wrote(4); | |
| 110 | |
| 111 // Patch bytes 0-3 | |
| 112 *(jint*)instr_addr = *(jint *)code_buffer; | |
| 113 | |
| 114 n_call->wrote(0); | |
| 115 | |
| 116 #ifdef ASSERT | |
| 117 // verify patching | |
| 118 for ( int i = 0; i < instruction_size; i++) { | |
| 119 address ptr = (address)((intptr_t)code_buffer + i); | |
| 120 int a_byte = (*ptr) & 0xFF; | |
| 121 assert(*((address)((intptr_t)instr_addr + i)) == a_byte, "mt safe patching failed"); | |
| 122 } | |
| 123 #endif | |
| 124 | |
| 125 } | |
| 126 | |
| 127 | |
| 128 // Similar to replace_mt_safe, but just changes the destination. The | |
| 129 // important thing is that free-running threads are able to execute this | |
| 130 // call instruction at all times. If the displacement field is aligned | |
| 131 // we can simply rely on atomicity of 32-bit writes to make sure other threads | |
| 132 // will see no intermediate states. Otherwise, the first two bytes of the | |
| 133 // call are guaranteed to be aligned, and can be atomically patched to a | |
| 134 // self-loop to guard the instruction while we change the other bytes. | |
| 135 | |
| 136 // We cannot rely on locks here, since the free-running threads must run at | |
| 137 // full speed. | |
| 138 // | |
| 139 // Used in the runtime linkage of calls; see class CompiledIC. | |
| 140 // (Cf. 4506997 and 4479829, where threads witnessed garbage displacements.) | |
| 141 void NativeCall::set_destination_mt_safe(address dest) { | |
| 142 debug_only(verify()); | |
| 143 // Make sure patching code is locked. No two threads can patch at the same | |
| 144 // time but one may be executing this code. | |
| 145 assert(Patching_lock->is_locked() || | |
| 146 SafepointSynchronize::is_at_safepoint(), "concurrent code patching"); | |
| 147 // Both C1 and C2 should now be generating code which aligns the patched address | |
| 148 // to be within a single cache line except that C1 does not do the alignment on | |
| 149 // uniprocessor systems. | |
| 150 bool is_aligned = ((uintptr_t)displacement_address() + 0) / cache_line_size == | |
| 151 ((uintptr_t)displacement_address() + 3) / cache_line_size; | |
| 152 | |
| 153 guarantee(!os::is_MP() || is_aligned, "destination must be aligned"); | |
| 154 | |
| 155 if (is_aligned) { | |
| 156 // Simple case: The destination lies within a single cache line. | |
| 157 set_destination(dest); | |
| 158 } else if ((uintptr_t)instruction_address() / cache_line_size == | |
| 159 ((uintptr_t)instruction_address()+1) / cache_line_size) { | |
| 160 // Tricky case: The instruction prefix lies within a single cache line. | |
| 161 intptr_t disp = dest - return_address(); | |
| 162 #ifdef AMD64 | |
| 163 guarantee(disp == (intptr_t)(jint)disp, "must be 32-bit offset"); | |
| 164 #endif // AMD64 | |
| 165 | |
| 166 int call_opcode = instruction_address()[0]; | |
| 167 | |
| 168 // First patch dummy jump in place: | |
| 169 { | |
| 170 u_char patch_jump[2]; | |
| 171 patch_jump[0] = 0xEB; // jmp rel8 | |
| 172 patch_jump[1] = 0xFE; // jmp to self | |
| 173 | |
| 174 assert(sizeof(patch_jump)==sizeof(short), "sanity check"); | |
| 175 *(short*)instruction_address() = *(short*)patch_jump; | |
| 176 } | |
| 177 // Invalidate. Opteron requires a flush after every write. | |
| 178 wrote(0); | |
| 179 | |
| 180 // (Note: We assume any reader which has already started to read | |
| 181 // the unpatched call will completely read the whole unpatched call | |
| 182 // without seeing the next writes we are about to make.) | |
| 183 | |
| 184 // Next, patch the last three bytes: | |
| 185 u_char patch_disp[5]; | |
| 186 patch_disp[0] = call_opcode; | |
| 187 *(int32_t*)&patch_disp[1] = (int32_t)disp; | |
| 188 assert(sizeof(patch_disp)==instruction_size, "sanity check"); | |
| 189 for (int i = sizeof(short); i < instruction_size; i++) | |
| 190 instruction_address()[i] = patch_disp[i]; | |
| 191 | |
| 192 // Invalidate. Opteron requires a flush after every write. | |
| 193 wrote(sizeof(short)); | |
| 194 | |
| 195 // (Note: We assume that any reader which reads the opcode we are | |
| 196 // about to repatch will also read the writes we just made.) | |
| 197 | |
| 198 // Finally, overwrite the jump: | |
| 199 *(short*)instruction_address() = *(short*)patch_disp; | |
| 200 // Invalidate. Opteron requires a flush after every write. | |
| 201 wrote(0); | |
| 202 | |
| 203 debug_only(verify()); | |
| 204 guarantee(destination() == dest, "patch succeeded"); | |
| 205 } else { | |
| 206 // Impossible: One or the other must be atomically writable. | |
| 207 ShouldNotReachHere(); | |
| 208 } | |
| 209 } | |
| 210 | |
| 211 | |
| 212 void NativeMovConstReg::verify() { | |
| 213 #ifdef AMD64 | |
| 214 // make sure code pattern is actually a mov reg64, imm64 instruction | |
| 215 if ((ubyte_at(0) != Assembler::REX_W && ubyte_at(0) != Assembler::REX_WB) || | |
| 216 (ubyte_at(1) & (0xff ^ register_mask)) != 0xB8) { | |
| 217 print(); | |
| 218 fatal("not a REX.W[B] mov reg64, imm64"); | |
| 219 } | |
| 220 #else | |
| 221 // make sure code pattern is actually a mov reg, imm32 instruction | |
| 222 u_char test_byte = *(u_char*)instruction_address(); | |
| 223 u_char test_byte_2 = test_byte & ( 0xff ^ register_mask); | |
| 224 if (test_byte_2 != instruction_code) fatal("not a mov reg, imm32"); | |
| 225 #endif // AMD64 | |
| 226 } | |
| 227 | |
| 228 | |
| 229 void NativeMovConstReg::print() { | |
| 230 tty->print_cr(PTR_FORMAT ": mov reg, " INTPTR_FORMAT, | |
| 231 instruction_address(), data()); | |
| 232 } | |
| 233 | |
| 234 //------------------------------------------------------------------- | |
| 235 | |
| 304 | 236 int NativeMovRegMem::instruction_start() const { |
| 237 int off = 0; | |
| 238 u_char instr_0 = ubyte_at(off); | |
| 239 | |
| 4759 | 240 // See comment in Assembler::locate_operand() about VEX prefixes. |
| 241 if (instr_0 == instruction_VEX_prefix_2bytes) { | |
| 242 assert((UseAVX > 0), "shouldn't have VEX prefix"); | |
| 243 NOT_LP64(assert((0xC0 & ubyte_at(1)) == 0xC0, "shouldn't have LDS and LES instructions")); | |
| 244 return 2; | |
| 245 } | |
| 246 if (instr_0 == instruction_VEX_prefix_3bytes) { | |
| 247 assert((UseAVX > 0), "shouldn't have VEX prefix"); | |
| 248 NOT_LP64(assert((0xC0 & ubyte_at(1)) == 0xC0, "shouldn't have LDS and LES instructions")); | |
| 249 return 3; | |
| 250 } | |
| 251 | |
| 304 | 252 // First check to see if we have a (prefixed or not) xor |
| 4759 | 253 if (instr_0 >= instruction_prefix_wide_lo && // 0x40 |
| 254 instr_0 <= instruction_prefix_wide_hi) { // 0x4f | |
| 304 | 255 off++; |
| 256 instr_0 = ubyte_at(off); | |
| 257 } | |
| 258 | |
| 259 if (instr_0 == instruction_code_xor) { | |
| 260 off += 2; | |
| 261 instr_0 = ubyte_at(off); | |
| 262 } | |
| 263 | |
| 264 // Now look for the real instruction and the many prefix/size specifiers. | |
| 265 | |
| 266 if (instr_0 == instruction_operandsize_prefix ) { // 0x66 | |
| 267 off++; // Not SSE instructions | |
| 268 instr_0 = ubyte_at(off); | |
| 269 } | |
| 0 | 270 |
| 4759 | 271 if ( instr_0 == instruction_code_xmm_ss_prefix || // 0xf3 |
| 304 | 272 instr_0 == instruction_code_xmm_sd_prefix) { // 0xf2 |
| 273 off++; | |
| 274 instr_0 = ubyte_at(off); | |
| 275 } | |
| 276 | |
| 4759 | 277 if ( instr_0 >= instruction_prefix_wide_lo && // 0x40 |
| 304 | 278 instr_0 <= instruction_prefix_wide_hi) { // 0x4f |
| 279 off++; | |
| 280 instr_0 = ubyte_at(off); | |
| 281 } | |
| 282 | |
| 283 | |
| 284 if (instr_0 == instruction_extended_prefix ) { // 0x0f | |
| 285 off++; | |
| 286 } | |
| 287 | |
| 288 return off; | |
| 289 } | |
| 290 | |
| 291 address NativeMovRegMem::instruction_address() const { | |
| 292 return addr_at(instruction_start()); | |
| 293 } | |
| 294 | |
| 295 address NativeMovRegMem::next_instruction_address() const { | |
| 296 address ret = instruction_address() + instruction_size; | |
| 297 u_char instr_0 = *(u_char*) instruction_address(); | |
| 298 switch (instr_0) { | |
| 299 case instruction_operandsize_prefix: | |
| 300 | |
| 301 fatal("should have skipped instruction_operandsize_prefix"); | |
| 302 break; | |
| 0 | 303 |
| 304 | 304 case instruction_extended_prefix: |
| 305 fatal("should have skipped instruction_extended_prefix"); | |
| 306 break; | |
| 307 | |
| 308 case instruction_code_mem2reg_movslq: // 0x63 | |
| 309 case instruction_code_mem2reg_movzxb: // 0xB6 | |
| 310 case instruction_code_mem2reg_movsxb: // 0xBE | |
| 311 case instruction_code_mem2reg_movzxw: // 0xB7 | |
| 312 case instruction_code_mem2reg_movsxw: // 0xBF | |
| 313 case instruction_code_reg2mem: // 0x89 (q/l) | |
| 314 case instruction_code_mem2reg: // 0x8B (q/l) | |
| 315 case instruction_code_reg2memb: // 0x88 | |
| 316 case instruction_code_mem2regb: // 0x8a | |
| 317 | |
| 318 case instruction_code_float_s: // 0xd9 fld_s a | |
| 319 case instruction_code_float_d: // 0xdd fld_d a | |
| 320 | |
| 321 case instruction_code_xmm_load: // 0x10 | |
| 322 case instruction_code_xmm_store: // 0x11 | |
| 323 case instruction_code_xmm_lpd: // 0x12 | |
| 324 { | |
| 325 // If there is an SIB then instruction is longer than expected | |
| 326 u_char mod_rm = *(u_char*)(instruction_address() + 1); | |
| 327 if ((mod_rm & 7) == 0x4) { | |
| 328 ret++; | |
| 329 } | |
| 330 } | |
| 331 case instruction_code_xor: | |
| 332 fatal("should have skipped xor lead in"); | |
| 333 break; | |
| 334 | |
| 335 default: | |
| 336 fatal("not a NativeMovRegMem"); | |
| 0 | 337 } |
| 304 | 338 return ret; |
| 339 | |
| 340 } | |
| 0 | 341 |
| 304 | 342 int NativeMovRegMem::offset() const{ |
| 343 int off = data_offset + instruction_start(); | |
| 344 u_char mod_rm = *(u_char*)(instruction_address() + 1); | |
| 345 // nnnn(r12|rsp) isn't coded as simple mod/rm since that is | |
| 346 // the encoding to use an SIB byte. Which will have the nnnn | |
| 347 // field off by one byte | |
| 348 if ((mod_rm & 7) == 0x4) { | |
| 349 off++; | |
| 0 | 350 } |
| 304 | 351 return int_at(off); |
| 352 } | |
| 353 | |
| 354 void NativeMovRegMem::set_offset(int x) { | |
| 355 int off = data_offset + instruction_start(); | |
| 356 u_char mod_rm = *(u_char*)(instruction_address() + 1); | |
| 357 // nnnn(r12|rsp) isn't coded as simple mod/rm since that is | |
| 358 // the encoding to use an SIB byte. Which will have the nnnn | |
| 359 // field off by one byte | |
| 360 if ((mod_rm & 7) == 0x4) { | |
| 361 off++; | |
| 362 } | |
| 363 set_int_at(off, x); | |
| 0 | 364 } |
| 365 | |
| 366 void NativeMovRegMem::verify() { | |
| 367 // make sure code pattern is actually a mov [reg+offset], reg instruction | |
| 368 u_char test_byte = *(u_char*)instruction_address(); | |
| 304 | 369 switch (test_byte) { |
| 370 case instruction_code_reg2memb: // 0x88 movb a, r | |
| 371 case instruction_code_reg2mem: // 0x89 movl a, r (can be movq in 64bit) | |
| 372 case instruction_code_mem2regb: // 0x8a movb r, a | |
| 373 case instruction_code_mem2reg: // 0x8b movl r, a (can be movq in 64bit) | |
| 374 break; | |
| 375 | |
| 376 case instruction_code_mem2reg_movslq: // 0x63 movsql r, a | |
| 377 case instruction_code_mem2reg_movzxb: // 0xb6 movzbl r, a (movzxb) | |
| 378 case instruction_code_mem2reg_movzxw: // 0xb7 movzwl r, a (movzxw) | |
| 379 case instruction_code_mem2reg_movsxb: // 0xbe movsbl r, a (movsxb) | |
| 380 case instruction_code_mem2reg_movsxw: // 0xbf movswl r, a (movsxw) | |
| 381 break; | |
| 382 | |
| 383 case instruction_code_float_s: // 0xd9 fld_s a | |
| 384 case instruction_code_float_d: // 0xdd fld_d a | |
| 385 case instruction_code_xmm_load: // 0x10 movsd xmm, a | |
| 386 case instruction_code_xmm_store: // 0x11 movsd a, xmm | |
| 387 case instruction_code_xmm_lpd: // 0x12 movlpd xmm, a | |
| 388 break; | |
| 389 | |
| 390 default: | |
| 0 | 391 fatal ("not a mov [reg+offs], reg instruction"); |
| 392 } | |
| 393 } | |
| 394 | |
| 395 | |
| 396 void NativeMovRegMem::print() { | |
| 397 tty->print_cr("0x%x: mov reg, [reg + %x]", instruction_address(), offset()); | |
| 398 } | |
| 399 | |
| 400 //------------------------------------------------------------------- | |
| 401 | |
| 402 void NativeLoadAddress::verify() { | |
| 403 // make sure code pattern is actually a mov [reg+offset], reg instruction | |
| 404 u_char test_byte = *(u_char*)instruction_address(); | |
| 304 | 405 #ifdef _LP64 |
| 406 if ( (test_byte == instruction_prefix_wide || | |
| 407 test_byte == instruction_prefix_wide_extended) ) { | |
| 408 test_byte = *(u_char*)(instruction_address() + 1); | |
| 409 } | |
| 410 #endif // _LP64 | |
| 411 if ( ! ((test_byte == lea_instruction_code) | |
| 412 LP64_ONLY(|| (test_byte == mov64_instruction_code) ))) { | |
| 0 | 413 fatal ("not a lea reg, [reg+offs] instruction"); |
| 414 } | |
| 415 } | |
| 416 | |
| 417 | |
| 418 void NativeLoadAddress::print() { | |
| 419 tty->print_cr("0x%x: lea [reg + %x], reg", instruction_address(), offset()); | |
| 420 } | |
| 421 | |
| 422 //-------------------------------------------------------------------------------- | |
| 423 | |
| 424 void NativeJump::verify() { | |
| 425 if (*(u_char*)instruction_address() != instruction_code) { | |
| 426 fatal("not a jump instruction"); | |
| 427 } | |
| 428 } | |
| 429 | |
| 430 | |
| 431 void NativeJump::insert(address code_pos, address entry) { | |
| 432 intptr_t disp = (intptr_t)entry - ((intptr_t)code_pos + 1 + 4); | |
| 433 #ifdef AMD64 | |
| 434 guarantee(disp == (intptr_t)(int32_t)disp, "must be 32-bit offset"); | |
| 435 #endif // AMD64 | |
| 436 | |
| 437 *code_pos = instruction_code; | |
| 438 *((int32_t*)(code_pos + 1)) = (int32_t)disp; | |
| 439 | |
| 440 ICache::invalidate_range(code_pos, instruction_size); | |
| 441 } | |
| 442 | |
| 443 void NativeJump::check_verified_entry_alignment(address entry, address verified_entry) { | |
| 444 // Patching to not_entrant can happen while activations of the method are | |
| 445 // in use. The patching in that instance must happen only when certain | |
| 446 // alignment restrictions are true. These guarantees check those | |
| 447 // conditions. | |
| 448 #ifdef AMD64 | |
| 449 const int linesize = 64; | |
| 450 #else | |
| 451 const int linesize = 32; | |
| 452 #endif // AMD64 | |
| 453 | |
| 454 // Must be wordSize aligned | |
| 455 guarantee(((uintptr_t) verified_entry & (wordSize -1)) == 0, | |
| 456 "illegal address for code patching 2"); | |
| 457 // First 5 bytes must be within the same cache line - 4827828 | |
| 458 guarantee((uintptr_t) verified_entry / linesize == | |
| 459 ((uintptr_t) verified_entry + 4) / linesize, | |
| 460 "illegal address for code patching 3"); | |
| 461 } | |
| 462 | |
| 463 | |
| 464 // MT safe inserting of a jump over an unknown instruction sequence (used by nmethod::makeZombie) | |
| 465 // The problem: jmp <dest> is a 5-byte instruction. Atomical write can be only with 4 bytes. | |
| 466 // First patches the first word atomically to be a jump to itself. | |
| 467 // Then patches the last byte and then atomically patches the first word (4-bytes), | |
| 468 // thus inserting the desired jump | |
| 469 // This code is mt-safe with the following conditions: entry point is 4 byte aligned, | |
| 470 // entry point is in same cache line as unverified entry point, and the instruction being | |
| 471 // patched is >= 5 byte (size of patch). | |
| 472 // | |
| 473 // In C2 the 5+ byte sized instruction is enforced by code in MachPrologNode::emit. | |
| 474 // In C1 the restriction is enforced by CodeEmitter::method_entry | |
| 475 // | |
| 476 void NativeJump::patch_verified_entry(address entry, address verified_entry, address dest) { | |
| 477 // complete jump instruction (to be inserted) is in code_buffer; | |
| 478 unsigned char code_buffer[5]; | |
| 479 code_buffer[0] = instruction_code; | |
| 480 intptr_t disp = (intptr_t)dest - ((intptr_t)verified_entry + 1 + 4); | |
| 481 #ifdef AMD64 | |
| 482 guarantee(disp == (intptr_t)(int32_t)disp, "must be 32-bit offset"); | |
| 483 #endif // AMD64 | |
| 484 *(int32_t*)(code_buffer + 1) = (int32_t)disp; | |
| 485 | |
| 486 check_verified_entry_alignment(entry, verified_entry); | |
| 487 | |
| 488 // Can't call nativeJump_at() because it's asserts jump exists | |
| 489 NativeJump* n_jump = (NativeJump*) verified_entry; | |
| 490 | |
| 491 //First patch dummy jmp in place | |
| 492 | |
| 493 unsigned char patch[4]; | |
| 494 assert(sizeof(patch)==sizeof(int32_t), "sanity check"); | |
| 495 patch[0] = 0xEB; // jmp rel8 | |
| 496 patch[1] = 0xFE; // jmp to self | |
| 497 patch[2] = 0xEB; | |
| 498 patch[3] = 0xFE; | |
| 499 | |
| 500 // First patch dummy jmp in place | |
| 501 *(int32_t*)verified_entry = *(int32_t *)patch; | |
| 502 | |
| 503 n_jump->wrote(0); | |
| 504 | |
| 505 // Patch 5th byte (from jump instruction) | |
| 506 verified_entry[4] = code_buffer[4]; | |
| 507 | |
| 508 n_jump->wrote(4); | |
| 509 | |
| 510 // Patch bytes 0-3 (from jump instruction) | |
| 511 *(int32_t*)verified_entry = *(int32_t *)code_buffer; | |
| 512 // Invalidate. Opteron requires a flush after every write. | |
| 513 n_jump->wrote(0); | |
| 514 | |
| 515 } | |
| 516 | |
| 517 void NativePopReg::insert(address code_pos, Register reg) { | |
| 518 assert(reg->encoding() < 8, "no space for REX"); | |
| 519 assert(NativePopReg::instruction_size == sizeof(char), "right address unit for update"); | |
| 520 *code_pos = (u_char)(instruction_code | reg->encoding()); | |
| 521 ICache::invalidate_range(code_pos, instruction_size); | |
| 522 } | |
| 523 | |
| 524 | |
| 525 void NativeIllegalInstruction::insert(address code_pos) { | |
| 526 assert(NativeIllegalInstruction::instruction_size == sizeof(short), "right address unit for update"); | |
| 527 *(short *)code_pos = instruction_code; | |
| 528 ICache::invalidate_range(code_pos, instruction_size); | |
| 529 } | |
| 530 | |
| 531 void NativeGeneralJump::verify() { | |
| 532 assert(((NativeInstruction *)this)->is_jump() || | |
| 533 ((NativeInstruction *)this)->is_cond_jump(), "not a general jump instruction"); | |
| 534 } | |
| 535 | |
| 536 | |
| 537 void NativeGeneralJump::insert_unconditional(address code_pos, address entry) { | |
| 538 intptr_t disp = (intptr_t)entry - ((intptr_t)code_pos + 1 + 4); | |
| 539 #ifdef AMD64 | |
| 540 guarantee(disp == (intptr_t)(int32_t)disp, "must be 32-bit offset"); | |
| 541 #endif // AMD64 | |
| 542 | |
| 543 *code_pos = unconditional_long_jump; | |
| 544 *((int32_t *)(code_pos+1)) = (int32_t) disp; | |
| 545 ICache::invalidate_range(code_pos, instruction_size); | |
| 546 } | |
| 547 | |
| 548 | |
| 549 // MT-safe patching of a long jump instruction. | |
| 550 // First patches first word of instruction to two jmp's that jmps to them | |
| 551 // selfs (spinlock). Then patches the last byte, and then atomicly replaces | |
| 552 // the jmp's with the first 4 byte of the new instruction. | |
| 553 void NativeGeneralJump::replace_mt_safe(address instr_addr, address code_buffer) { | |
| 554 assert (instr_addr != NULL, "illegal address for code patching (4)"); | |
| 555 NativeGeneralJump* n_jump = nativeGeneralJump_at (instr_addr); // checking that it is a jump | |
| 556 | |
| 557 // Temporary code | |
| 558 unsigned char patch[4]; | |
| 559 assert(sizeof(patch)==sizeof(int32_t), "sanity check"); | |
| 560 patch[0] = 0xEB; // jmp rel8 | |
| 561 patch[1] = 0xFE; // jmp to self | |
| 562 patch[2] = 0xEB; | |
| 563 patch[3] = 0xFE; | |
| 564 | |
| 565 // First patch dummy jmp in place | |
| 566 *(int32_t*)instr_addr = *(int32_t *)patch; | |
| 567 n_jump->wrote(0); | |
| 568 | |
| 569 // Patch 4th byte | |
| 570 instr_addr[4] = code_buffer[4]; | |
| 571 | |
| 572 n_jump->wrote(4); | |
| 573 | |
| 574 // Patch bytes 0-3 | |
| 575 *(jint*)instr_addr = *(jint *)code_buffer; | |
| 576 | |
| 577 n_jump->wrote(0); | |
| 578 | |
| 579 #ifdef ASSERT | |
| 580 // verify patching | |
| 581 for ( int i = 0; i < instruction_size; i++) { | |
| 582 address ptr = (address)((intptr_t)code_buffer + i); | |
| 583 int a_byte = (*ptr) & 0xFF; | |
| 584 assert(*((address)((intptr_t)instr_addr + i)) == a_byte, "mt safe patching failed"); | |
| 585 } | |
| 586 #endif | |
| 587 | |
| 588 } | |
| 589 | |
| 590 | |
| 591 | |
| 592 address NativeGeneralJump::jump_destination() const { | |
| 593 int op_code = ubyte_at(0); | |
| 594 bool is_rel32off = (op_code == 0xE9 || op_code == 0x0F); | |
| 595 int offset = (op_code == 0x0F) ? 2 : 1; | |
| 596 int length = offset + ((is_rel32off) ? 4 : 1); | |
| 597 | |
| 598 if (is_rel32off) | |
| 599 return addr_at(0) + length + int_at(offset); | |
| 600 else | |
| 601 return addr_at(0) + length + sbyte_at(offset); | |
| 602 } | |
|
116
018d5b58dd4f
6537506: Provide a mechanism for specifying Java-level USDT-like dtrace probes
kamg
parents:
0
diff
changeset
|
603 |
|
018d5b58dd4f
6537506: Provide a mechanism for specifying Java-level USDT-like dtrace probes
kamg
parents:
0
diff
changeset
|
604 bool NativeInstruction::is_dtrace_trap() { |
|
018d5b58dd4f
6537506: Provide a mechanism for specifying Java-level USDT-like dtrace probes
kamg
parents:
0
diff
changeset
|
605 return (*(int32_t*)this & 0xff) == 0xcc; |
|
018d5b58dd4f
6537506: Provide a mechanism for specifying Java-level USDT-like dtrace probes
kamg
parents:
0
diff
changeset
|
606 } |