/* src/vm/jit/x86_64/patcher.c - x86_64 code patching functions Copyright (C) 1996-2005, 2006, 2007, 2008, 2009, 2010 CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO This file is part of CACAO. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include "config.h" #include #include "vm/types.h" #include "vm/jit/x86_64/codegen.h" #include "vm/jit/x86_64/md.h" #include "mm/memory.hpp" #include "native/native.hpp" #include "vm/jit/builtin.hpp" #include "vm/class.hpp" #include "vm/field.hpp" #include "vm/initialize.hpp" #include "vm/options.h" #include "vm/references.h" #include "vm/resolve.hpp" #include "vm/jit/patcher-common.hpp" /* patcher_patch_code ********************************************************** Just patches back the original machine code. *******************************************************************************/ void patcher_patch_code(patchref_t *pr) { *((uint16_t*) pr->mpc) = (uint16_t) pr->mcode; md_icacheflush((void*) pr->mpc, PATCHER_CALL_SIZE); } /** * Check if the trap instruction at the given PC is valid. * * @param pc Program counter. * * @return true if valid, false otherwise. */ bool patcher_is_valid_trap_instruction_at(void* pc) { uint16_t mcode = *((uint16_t*) pc); // Check for the undefined instruction we use. return (mcode == 0x0b0f); } /** * Overwrites the MFENCE instruction at the indicated address with a 3-byte * NOP. The MFENCE instruction is not allowed to cross a (4-byte) word * boundary. * * @param pc Program counter. */ static void patch_out_mfence(void *pc) { uint32_t *p = (uint32_t*) (((uintptr_t) pc) & ~3); assert((((uintptr_t) pc) & 3) < 2); if (((uintptr_t) pc) & 1) *p = (*p & 0x000000ff) | 0x001f0f00; else *p = (*p & 0xff000000) | 0x00001f0f; md_icacheflush(p, 4); } /* patcher_resolve_classref_to_classinfo *************************************** ACONST: 48 bf a0 f0 92 00 00 00 00 00 mov $0x92f0a0,%rdi MULTIANEWARRAY: 48 be 30 40 b2 00 00 00 00 00 mov $0xb24030,%rsi 48 89 e2 mov %rsp,%rdx 48 b8 7c 96 4b 00 00 00 00 00 mov $0x4b967c,%rax 48 ff d0 callq *%rax ARRAYCHECKCAST: 48 be b8 3f b2 00 00 00 00 00 mov $0xb23fb8,%rsi 48 b8 00 00 00 00 00 00 00 00 mov $0x0,%rax 48 ff d0 callq *%rax *******************************************************************************/ bool patcher_resolve_classref_to_classinfo(patchref_t *pr) { constant_classref* cr = (constant_classref*) pr->ref; uintptr_t* datap = (uintptr_t*) pr->datap; // Resolve the class. classinfo* c = resolve_classref_eager(cr); if (c == NULL) return false; // Patch the class. *datap = (uintptr_t) c; // Synchronize data cache. md_dcacheflush((void*) pr->datap, SIZEOF_VOID_P); // Patch back the original code. patcher_patch_code(pr); return true; } /* patcher_resolve_classref_to_vftbl ******************************************* CHECKCAST (class): INSTANCEOF (class): *******************************************************************************/ bool patcher_resolve_classref_to_vftbl(patchref_t *pr) { constant_classref* cr = (constant_classref*) pr->ref; uintptr_t* datap = (uintptr_t*) pr->datap; // Resolve the field. classinfo* c = resolve_classref_eager(cr); if (c == NULL) return false; // Patch super class' vftbl. *datap = (uintptr_t) c->vftbl; // Synchronize data cache. md_dcacheflush((void*) pr->datap, SIZEOF_VOID_P); // Patch back the original code. patcher_patch_code(pr); return true; } /* patcher_resolve_classref_to_flags ******************************************* CHECKCAST/INSTANCEOF: *******************************************************************************/ bool patcher_resolve_classref_to_flags(patchref_t *pr) { constant_classref* cr = (constant_classref*) pr->ref; /* int32_t* datap = (int32_t*) pr->datap; */ uint8_t* ra = (uint8_t*) pr->mpc; // Resolve the field. classinfo* c = resolve_classref_eager(cr); if (c == NULL) return false; ra += PATCHER_CALL_SIZE; // Patch class flags. /* *datap = c->flags; */ *((int32_t*) (ra + 2)) = c->flags; // Synchronize data cache. /* md_dcacheflush(datap, sizeof(int32_t)); */ md_icacheflush(ra + 2, sizeof(int32_t)); // Patch back the original code. patcher_patch_code(pr); return true; } /* patcher_get_putstatic ******************************************************* Machine code: 4d 8b 15 86 fe ff ff mov -378(%rip),%r10 49 8b 32 mov (%r10),%rsi *******************************************************************************/ bool patcher_get_putstatic(patchref_t *pr) { unresolved_field* uf = (unresolved_field*) pr->ref; uintptr_t* datap = (uintptr_t*) pr->datap; uint8_t* ra = (uint8_t*) pr->mpc; // Resolve the field. fieldinfo* fi = resolve_field_eager(uf); if (fi == NULL) return false; ra += PATCHER_CALL_SIZE; // Check if the field's class is initialized/ if (!(fi->clazz->state & CLASS_INITIALIZED)) if (!initialize_class(fi->clazz)) return false; // Patch the field value's address. *datap = (uintptr_t) fi->value; if (pr->disp_mb && !(fi->flags & ACC_VOLATILE)) patch_out_mfence(ra + pr->disp_mb - 2); // Synchronize data cache. md_dcacheflush((void*) pr->datap, SIZEOF_VOID_P); // Patch back the original code. patcher_patch_code(pr); return true; } /* patcher_get_putfield ******************************************************** Machine code: 45 8b 8f 00 00 00 00 mov 0x0(%r15),%r9d *******************************************************************************/ bool patcher_get_putfield(patchref_t *pr) { uint8_t* pc = (uint8_t*) pr->mpc; unresolved_field* uf = (unresolved_field*) pr->ref; // Resolve the field. fieldinfo* fi = resolve_field_eager(uf); if (fi == NULL) return false; pc += PATCHER_CALL_SIZE; // Patch the field's offset: we check for the field type, because // the instructions have different lengths. if (IS_INT_LNG_TYPE(fi->type)) { // Check for special case: %rsp or %r12 as base register. if (pc[3] == 0x24) *((int32_t*) (pc + 4)) = fi->offset; else *((int32_t*) (pc + 3)) = fi->offset; } else { // Check for special case: %rsp or %r12 as base register. if (pc[5] == 0x24) *((int32_t*) (pc + 6)) = fi->offset; else *((int32_t*) (pc + 5)) = fi->offset; } if (pr->disp_mb && !(fi->flags & ACC_VOLATILE)) patch_out_mfence(pc + pr->disp_mb - 2); // Synchronize instruction cache. md_icacheflush(pc, 6 + sizeof(int32_t)); // Patch back the original code. patcher_patch_code(pr); return true; } /* patcher_putfieldconst ******************************************************* Machine code: 41 c7 85 00 00 00 00 7b 00 00 00 movl $0x7b,0x0(%r13) *******************************************************************************/ bool patcher_putfieldconst(patchref_t *pr) { uint8_t* pc = (uint8_t*) pr->mpc; unresolved_field* uf = (unresolved_field*) pr->ref; // Resolve the field. fieldinfo* fi = resolve_field_eager(uf); if (fi == NULL) return false; pc += PATCHER_CALL_SIZE; // Patch the field's offset. if (IS_2_WORD_TYPE(fi->type) || IS_ADR_TYPE(fi->type)) { // Handle special case when the base register is %r12. if (pc[12] == 0x94) *((uint32_t*) (pc + 14)) = fi->offset; else *((uint32_t*) (pc + 13)) = fi->offset; } else { // Handle special case when the base register is %r12. if (pc[2] == 0x84) *((uint32_t*) (pc + 4)) = fi->offset; else *((uint32_t*) (pc + 3)) = fi->offset; } if (pr->disp_mb && !(fi->flags & ACC_VOLATILE)) patch_out_mfence(pc + pr->disp_mb - 2); // Synchronize instruction cache. md_icacheflush(pc, 14 + sizeof(int32_t)); // Patch back the original code. patcher_patch_code(pr); return true; } /* patcher_invokestatic_special ************************************************ Machine code: 49 ba 00 00 00 00 00 00 00 00 mov $0x0,%r10 49 ff d2 callq *%r10 *******************************************************************************/ bool patcher_invokestatic_special(patchref_t *pr) { unresolved_method* um = (unresolved_method*) pr->ref; uintptr_t* datap = (uintptr_t*) pr->datap; // Resolve the method. methodinfo* m = resolve_method_eager(um); if (m == NULL) return false; // Patch stubroutine. *datap = (uintptr_t) m->stubroutine; // Synchronize data cache. md_dcacheflush((void*) pr->datap, SIZEOF_VOID_P); // Patch back the original code. patcher_patch_code(pr); return true; } /* patcher_invokevirtual ******************************************************* Machine code: 4c 8b 17 mov (%rdi),%r10 49 8b 82 00 00 00 00 mov 0x0(%r10),%rax 48 ff d0 callq *%rax *******************************************************************************/ bool patcher_invokevirtual(patchref_t *pr) { uint8_t* pc = (uint8_t*) pr->mpc; unresolved_method* um = (unresolved_method*) pr->ref; // Resovlve the method. methodinfo* m = resolve_method_eager(um); if (m == NULL) return false; pc += PATCHER_CALL_SIZE; // Patch vftbl index. *((int32_t*) (pc + 3 + 3)) = (int32_t) (OFFSET(vftbl_t, table[0]) + sizeof(methodptr) * m->vftblindex); // Synchronize instruction cache. md_icacheflush(pc + 3 + 3, SIZEOF_VOID_P); // Patch back the original code. patcher_patch_code(pr); return true; } /* patcher_invokeinterface ***************************************************** Machine code: 4c 8b 17 mov (%rdi),%r10 4d 8b 92 00 00 00 00 mov 0x0(%r10),%r10 49 8b 82 00 00 00 00 mov 0x0(%r10),%rax 48 ff d0 callq *%rax *******************************************************************************/ bool patcher_invokeinterface(patchref_t *pr) { uint8_t* pc = (uint8_t*) pr->mpc; unresolved_method* um = (unresolved_method*) pr->ref; // Resolve the method. methodinfo* m = resolve_method_eager(um); if (m == NULL) return false; pc += PATCHER_CALL_SIZE; // Patch interfacetable index. *((int32_t*) (pc + 3 + 3)) = (int32_t) (OFFSET(vftbl_t, interfacetable[0]) - sizeof(methodptr) * m->clazz->index); // Patch method offset. *((int32_t*) (pc + 3 + 7 + 3)) = (int32_t) (sizeof(methodptr) * (m - m->clazz->methods)); // Synchronize instruction cache. md_icacheflush(pc + 3 + 3, SIZEOF_VOID_P + 3 + SIZEOF_VOID_P); // Patch back the original code. patcher_patch_code(pr); return true; } /* patcher_checkcast_interface ************************************************* Machine code: 45 8b 9a 1c 00 00 00 mov 0x1c(%r10),%r11d 41 81 fb 00 00 00 00 cmp $0x0,%r11d 0f 8f 08 00 00 00 jg 0x00002aaaaae511d5 48 8b 0c 25 03 00 00 00 mov 0x3,%rcx 4d 8b 9a 00 00 00 00 mov 0x0(%r10),%r11 *******************************************************************************/ bool patcher_checkcast_interface(patchref_t *pr) { uint8_t* pc = (uint8_t*) pr->mpc; constant_classref* cr = (constant_classref*) pr->ref; // Resolve the class. classinfo* c = resolve_classref_eager(cr); if (c == NULL) return false; pc += PATCHER_CALL_SIZE; // Patch super class index. *((int32_t*) (pc + 7 + 3)) = c->index; *((int32_t*) (pc + 7 + 7 + 6 + 8 + 3)) = (int32_t) (OFFSET(vftbl_t, interfacetable[0]) - c->index * sizeof(methodptr*)); // Synchronize instruction cache. md_icacheflush(pc + 7 + 3, sizeof(int32_t) + 6 + 8 + 3 + sizeof(int32_t)); // Patch back the original code. patcher_patch_code(pr); return true; } /* patcher_instanceof_interface ************************************************ Machine code: 45 8b 9a 1c 00 00 00 mov 0x1c(%r10),%r11d 41 81 fb 00 00 00 00 cmp $0x0,%r11d 0f 8e 94 04 00 00 jle 0x00002aaaaab018f8 4d 8b 9a 00 00 00 00 mov 0x0(%r10),%r11 *******************************************************************************/ bool patcher_instanceof_interface(patchref_t *pr) { uint8_t* pc = (uint8_t*) pr->mpc; constant_classref* cr = (constant_classref*) pr->ref; // Resolve the class. classinfo* c = resolve_classref_eager(cr); if (c == NULL) return false; pc += PATCHER_CALL_SIZE; // Patch super class index. *((int32_t*) (pc + 7 + 3)) = c->index; *((int32_t*) (pc + 7 + 7 + 6 + 3)) = (int32_t) (OFFSET(vftbl_t, interfacetable[0]) - c->index * sizeof(methodptr*)); // Synchronize instruction cache. md_icacheflush(pc + 7 + 3, sizeof(int32_t) + 6 + 3 + sizeof(int32_t)); // Patch back the original code. patcher_patch_code(pr); return true; } /* * These are local overrides for various environment variables in Emacs. * Please do not remove this and leave it at the end of the file, where * Emacs will automagically detect them. * --------------------------------------------------------------------- * Local variables: * mode: c * indent-tabs-mode: t * c-basic-offset: 4 * tab-width: 4 * End: * vim:noexpandtab:sw=4:ts=4: */