dr_emit_flags_t memdump_bb_instrumentation(void *drcontext, void *tag, instrlist_t *bb, instr_t *instr, bool for_trace, bool translating, void *user_data) { reg_id_t reg1 = DR_REG_XAX; reg_id_t reg2 = DR_REG_XBX; int i = 0; if(filter_bb_level_from_list(app_pc_head, instr)){ dr_save_reg(drcontext, bb, instr, reg1, SPILL_SLOT_1); dr_save_reg(drcontext, bb, instr, reg2, SPILL_SLOT_2); dr_mutex_lock(mutex); DEBUG_PRINT("instrumenting %x pc\n", instr_get_app_pc(instr)); instr_clones[instr_clone_amount] = instr_clone(drcontext, instr); for (i = 0; i < instr_num_srcs(instr); i++){ if (opnd_is_memory_reference(instr_get_src(instr, i))) { drutil_insert_get_mem_addr(drcontext, bb, instr, instr_get_src(instr,i), reg1, reg2); dr_insert_clean_call(drcontext, bb, instr, clean_call_mem_information, false, 3, OPND_CREATE_INTPTR(instr_clones[instr_clone_amount]), opnd_create_reg(reg1), OPND_CREATE_INTPTR(false)); } } for (i = 0; i < instr_num_dsts(instr); i++){ if (opnd_is_memory_reference(instr_get_dst(instr, i))) { drutil_insert_get_mem_addr(drcontext, bb, instr, instr_get_dst(instr, i), reg1, reg2); dr_insert_clean_call(drcontext, bb, instr, clean_call_mem_information, false, 3, OPND_CREATE_INTPTR(instr_clones[instr_clone_amount]), opnd_create_reg(reg1), OPND_CREATE_INTPTR(true)); } } instr_clone_amount++; dr_mutex_unlock(mutex); dr_restore_reg(drcontext, bb, instr, reg1, SPILL_SLOT_1); dr_restore_reg(drcontext, bb, instr, reg2, SPILL_SLOT_2); } return DR_EMIT_DEFAULT; }
/* * Function that tests a single operand of an instruction to see if * it's a memory reference, and if so, adds a call to log_mem. */ static void try_mem_opnd( void *drcontext, instrlist_t *bb, instr_t *instr, char **loc, opnd_t opnd, bool write) { if (!opnd_is_memory_reference(opnd)) return; instr_format_location(instr, loc); reg_id_t r0, r1; drreg_status_t st; st = drreg_reserve_register(drcontext, bb, instr, NULL, &r0); DR_ASSERT(st == DRREG_SUCCESS); st = drreg_reserve_register(drcontext, bb, instr, NULL, &r1); DR_ASSERT(st == DRREG_SUCCESS); bool ok = drutil_insert_get_mem_addr(drcontext, bb, instr, opnd, r0, r1); DR_ASSERT(ok); uint size = drutil_opnd_mem_size_in_bytes(opnd, instr); dr_insert_clean_call( drcontext, bb, instr, (void *)log_mem, false, 4, opnd_create_reg(r0), OPND_CREATE_INT32(size), OPND_CREATE_INT32(write), OPND_CREATE_INTPTR(*loc)); st = drreg_unreserve_register(drcontext, bb, instr, r1); DR_ASSERT(st == DRREG_SUCCESS); st = drreg_unreserve_register(drcontext, bb, instr, r0); DR_ASSERT(st == DRREG_SUCCESS); }
static void insert_save_addr(void *drcontext, instrlist_t *ilist, instr_t *where, opnd_t ref, reg_id_t reg_ptr, reg_id_t reg_addr) { bool ok; /* we use reg_ptr as scratch to get addr */ ok = drutil_insert_get_mem_addr(drcontext, ilist, where, ref, reg_addr, reg_ptr); DR_ASSERT(ok); insert_load_buf_ptr(drcontext, ilist, where, reg_ptr); MINSERT(ilist, where, XINST_CREATE_store(drcontext, OPND_CREATE_MEMPTR(reg_ptr, offsetof(mem_ref_t, addr)), opnd_create_reg(reg_addr))); }
void offline_instru_t::insert_save_addr(void *drcontext, instrlist_t *ilist, instr_t *where, reg_id_t reg_ptr, reg_id_t reg_addr, int adjust, opnd_t ref) { bool ok; int disp = adjust; if (opnd_uses_reg(ref, reg_ptr)) drreg_get_app_value(drcontext, ilist, where, reg_ptr, reg_ptr); if (opnd_uses_reg(ref, reg_addr)) drreg_get_app_value(drcontext, ilist, where, reg_addr, reg_addr); // We use reg_ptr as scratch to get the address. ok = drutil_insert_get_mem_addr(drcontext, ilist, where, ref, reg_addr, reg_ptr); DR_ASSERT(ok); // drutil_insert_get_mem_addr may clobber reg_ptr, so we need to re-load reg_ptr. // XXX i#2001: determine whether we have to and avoid it when we don't. insert_load_buf_ptr(drcontext, ilist, where, reg_ptr); MINSERT(ilist, where, XINST_CREATE_store(drcontext, OPND_CREATE_MEMPTR(reg_ptr, disp), opnd_create_reg(reg_addr))); // We allow either 0 or all 1's as the type so no need to write anything else. }
static void dynamic_info_instrumentation(void *drcontext, instrlist_t *ilist, instr_t *where, instr_t * static_info) { /* issues that may arise 1. pc and eflags is uint but in 64 bit mode 8 byte transfers are done -> so far no problem (need to see this) need to see whether there is a better way 2. double check all the printing */ /* this function does the acutal instrumentation arguments - we get a filled pointer here about the operand types for a given instruction (srcs and dests) 1) increment the pointer to the instr_trace buffers 2) add this pointer to instr_trace_t wrapper 3) check whether any of the srcs and dests have memory operations; if so add a lea instruction and get the dynamic address Add this address to instr_trace_t structure 4) if the buffer is full call a function to dump it to the file and restore the head ptr of the buffer (lean function is used utilizing a code cache to limit code bloat needed for a clean call before every instruction.) */ instr_t *instr, *call, *restore, *first, *second; opnd_t ref, opnd1, opnd2; reg_id_t reg1 = DR_REG_XBX; /* We can optimize it by picking dead reg */ reg_id_t reg2 = DR_REG_XCX; /* reg2 must be ECX or RCX for jecxz */ reg_id_t reg3 = DR_REG_XAX; per_thread_t *data; uint pc; uint i; module_data_t * module_data; if (client_arg->instrace_mode == DISASSEMBLY_TRACE){ dr_insert_clean_call(drcontext, ilist, where, clean_call_disassembly_trace, false, 0); return; } data = drmgr_get_tls_field(drcontext, tls_index); /* Steal the register for memory reference address * * We can optimize away the unnecessary register save and restore * by analyzing the code and finding the register is dead. */ dr_save_reg(drcontext, ilist, where, reg1, SPILL_SLOT_2); dr_save_reg(drcontext, ilist, where, reg2, SPILL_SLOT_3); dr_save_reg(drcontext, ilist, where, reg3, SPILL_SLOT_4); drmgr_insert_read_tls_field(drcontext, tls_index, ilist, where, reg2); /* Load data->buf_ptr into reg2 */ opnd1 = opnd_create_reg(reg2); opnd2 = OPND_CREATE_MEMPTR(reg2, offsetof(per_thread_t, buf_ptr)); instr = INSTR_CREATE_mov_ld(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* buf_ptr->static_info_instr = static_info; */ /* Move static_info to static_info_instr field of buf (which is a instr_trace_t *) */ opnd1 = OPND_CREATE_MEMPTR(reg2, offsetof(instr_trace_t, static_info_instr)); instrlist_insert_mov_immed_ptrsz(drcontext, (ptr_int_t)static_info, opnd1, ilist, where, &first, &second); /* buf_ptr->num_mem = 0; */ opnd1 = OPND_CREATE_MEMPTR(reg2, offsetof(instr_trace_t, num_mem)); instrlist_insert_mov_immed_ptrsz(drcontext, (ptr_int_t)0, opnd1, ilist, where, &first, &second); for (i = 0; i<instr_num_dsts(where); i++){ if (opnd_is_memory_reference(instr_get_dst(where, i))){ ref = instr_get_dst(where, i); DR_ASSERT(opnd_is_null(ref) == false); dr_restore_reg(drcontext, ilist, where, reg1, SPILL_SLOT_2); dr_restore_reg(drcontext, ilist, where, reg2, SPILL_SLOT_3); #ifdef DEBUG_MEM_REGS dr_insert_clean_call(drcontext, ilist, where, clean_call_disassembly_trace, false, 0); dr_insert_clean_call(drcontext, ilist, where, clean_call_print_regvalues, false, 0); #endif drutil_insert_get_mem_addr(drcontext, ilist, where, ref, reg1, reg2); #ifdef DEBUG_MEM_REGS dr_insert_clean_call(drcontext, ilist, where, clean_call_print_regvalues, false, 0); #endif #ifdef DEBUG_MEM_STATS dr_insert_clean_call(drcontext, ilist, where, clean_call_disassembly_trace, false, 0); dr_insert_clean_call(drcontext, ilist, where, clean_call_mem_stats, false, 1, opnd_create_reg(reg1)); #endif dr_insert_clean_call(drcontext, ilist, where, clean_call_populate_mem, false, 3, opnd_create_reg(reg1), OPND_CREATE_INT32(i), OPND_CREATE_INT32(DST_TYPE)); } } for (i = 0; i<instr_num_srcs(where); i++){ if (opnd_is_memory_reference(instr_get_src(where, i))){ ref = instr_get_src(where, i); DR_ASSERT(opnd_is_null(ref) == false); dr_restore_reg(drcontext, ilist, where, reg1, SPILL_SLOT_2); dr_restore_reg(drcontext, ilist, where, reg2, SPILL_SLOT_3); #ifdef DEBUG_MEM_REGS dr_insert_clean_call(drcontext, ilist, where, clean_call_disassembly_trace, false, 0); dr_insert_clean_call(drcontext, ilist, where, clean_call_print_regvalues, false, 0); #endif drutil_insert_get_mem_addr(drcontext, ilist, where, ref, reg1, reg2); #ifdef DEBUG_MEM_REGS dr_insert_clean_call(drcontext, ilist, where, clean_call_print_regvalues, false, 0); #endif #ifdef DEBUG_MEM_STATS dr_insert_clean_call(drcontext, ilist, where, clean_call_disassembly_trace, false, 0); dr_insert_clean_call(drcontext, ilist, where, clean_call_mem_stats, false, 1, opnd_create_reg(reg1)); #endif dr_insert_clean_call(drcontext, ilist, where, clean_call_populate_mem, false, 3, opnd_create_reg(reg1), OPND_CREATE_INT32(i), OPND_CREATE_INT32(SRC_TYPE)); } } drmgr_insert_read_tls_field(drcontext, tls_index, ilist, where, reg2); /* Load data->buf_ptr into reg2 */ opnd1 = opnd_create_reg(reg2); opnd2 = OPND_CREATE_MEMPTR(reg2, offsetof(per_thread_t, buf_ptr)); instr = INSTR_CREATE_mov_ld(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* arithmetic flags are saved here for buf_ptr->eflags filling */ dr_save_arith_flags_to_xax(drcontext, ilist, where); /* load the eflags */ opnd1 = OPND_CREATE_MEMPTR(reg2, offsetof(instr_trace_t, eflags)); opnd2 = opnd_create_reg(reg3); instr = INSTR_CREATE_mov_st(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* load the app_pc */ opnd1 = OPND_CREATE_MEMPTR(reg2, offsetof(instr_trace_t, pc)); module_data = dr_lookup_module(instr_get_app_pc(where)); //dynamically generated code - module information not available - then just store 0 at the pc slot of the instr_trace data if (module_data != NULL){ pc = instr_get_app_pc(where) - module_data->start; dr_free_module_data(module_data); } else{ pc = 0; } instrlist_insert_mov_immed_ptrsz(drcontext, (ptr_int_t)pc, opnd1, ilist, where, &first, &second); /* buf_ptr++; */ /* Increment reg value by pointer size using lea instr */ opnd1 = opnd_create_reg(reg2); opnd2 = opnd_create_base_disp(reg2, DR_REG_NULL, 0, sizeof(instr_trace_t), OPSZ_lea); instr = INSTR_CREATE_lea(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* Update the data->buf_ptr */ drmgr_insert_read_tls_field(drcontext, tls_index, ilist, where, reg1); opnd1 = OPND_CREATE_MEMPTR(reg1, offsetof(per_thread_t, buf_ptr)); opnd2 = opnd_create_reg(reg2); instr = INSTR_CREATE_mov_st(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* we use lea + jecxz trick for better performance * lea and jecxz won't disturb the eflags, so we won't insert * code to save and restore application's eflags. */ /* lea [reg2 - buf_end] => reg2 */ opnd1 = opnd_create_reg(reg1); opnd2 = OPND_CREATE_MEMPTR(reg1, offsetof(per_thread_t, buf_end)); instr = INSTR_CREATE_mov_ld(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); opnd1 = opnd_create_reg(reg2); opnd2 = opnd_create_base_disp(reg1, reg2, 1, 0, OPSZ_lea); instr = INSTR_CREATE_lea(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* jecxz call */ call = INSTR_CREATE_label(drcontext); opnd1 = opnd_create_instr(call); instr = INSTR_CREATE_jecxz(drcontext, opnd1); instrlist_meta_preinsert(ilist, where, instr); /* jump restore to skip clean call */ restore = INSTR_CREATE_label(drcontext); opnd1 = opnd_create_instr(restore); instr = INSTR_CREATE_jmp(drcontext, opnd1); instrlist_meta_preinsert(ilist, where, instr); /* clean call */ /* We jump to lean procedure which performs full context switch and * clean call invocation. This is to reduce the code cache size. */ instrlist_meta_preinsert(ilist, where, call); /* mov restore DR_REG_XCX */ opnd1 = opnd_create_reg(reg2); /* this is the return address for jumping back from lean procedure */ opnd2 = opnd_create_instr(restore); /* We could use instrlist_insert_mov_instr_addr(), but with a register * destination we know we can use a 64-bit immediate. */ instr = INSTR_CREATE_mov_imm(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* jmp code_cache */ opnd1 = opnd_create_pc(code_cache); instr = INSTR_CREATE_jmp(drcontext, opnd1); instrlist_meta_preinsert(ilist, where, instr); /* restore %reg */ instrlist_meta_preinsert(ilist, where, restore); //dr_restore_arith_flags_from_xax(drcontext, ilist, where); dr_restore_reg(drcontext, ilist, where, reg1, SPILL_SLOT_2); dr_restore_reg(drcontext, ilist, where, reg2, SPILL_SLOT_3); dr_restore_reg(drcontext, ilist, where, reg3, SPILL_SLOT_4); //instrlist_disassemble(drcontext, instr_get_app_pc(instrlist_first(ilist)), ilist, logfile); }
static void instrument_mem(void *drcontext, instrlist_t *ilist, instr_t *where, int pos, bool write) { instr_t *instr; opnd_t ref, opnd1, opnd2; reg_id_t reg1 = DR_REG_XAX; /* We can optimize it by picking dead reg */ reg_id_t reg2 = DR_REG_XCX; /* reg2 must be ECX or RCX for jecxz */ if (write) ref = instr_get_dst(where, pos); else ref = instr_get_src(where, pos); dr_save_reg(drcontext, ilist, where, reg1, SPILL_SLOT_2); dr_save_reg(drcontext, ilist, where, reg2, SPILL_SLOT_3); // reg2 = RBufIdx opnd1 = opnd_create_reg(reg2); opnd2 = OPND_CREATE_ABSMEM((byte *)&RBufIdx, OPSZ_4); instr = INSTR_CREATE_mov_ld(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); // save flags since we are using inc, and dr_save_arith_flags_to_xax(drcontext, ilist, where); // reg2 = reg2 & RBUF_SIZE opnd1 = opnd_create_reg(reg2); opnd2 = OPND_CREATE_INT32(RBUF_SIZE); instr = INSTR_CREATE_and(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); dr_restore_arith_flags_from_xax(drcontext, ilist, where); // reg1 = &RBuf opnd1 = opnd_create_reg(reg1); opnd2 = OPND_CREATE_INTPTR(RBuf); instr = INSTR_CREATE_mov_imm(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); // reg1 = reg1 + reg2 * sizeof(uint) // = RBuf + RBufIdx * sizeof(uint) // = RBuf[RBufIdx] opnd1 = opnd_create_reg(reg1); opnd2 = opnd_create_base_disp(reg1, reg2, sizeof(uint), 0, OPSZ_lea); instr = INSTR_CREATE_lea(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); // RBuf[RBufIdx].addr = addr; opnd1 = OPND_CREATE_MEMPTR(reg1, 0); drutil_insert_get_mem_addr(drcontext, ilist, where, ref, reg2, reg1); opnd2 = opnd_create_reg(reg2); instr = INSTR_CREATE_mov_st(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); dr_save_arith_flags_to_xax(drcontext, ilist, where); // reg2 = RBufIdx opnd1 = opnd_create_reg(reg2); opnd2 = OPND_CREATE_ABSMEM((byte *)&RBufIdx, OPSZ_4); instr = INSTR_CREATE_mov_ld(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); // reg2 = reg2 + 1 opnd1 = opnd_create_reg(reg2); instr = INSTR_CREATE_inc(drcontext, opnd1); instrlist_meta_preinsert(ilist, where, instr); // RBufIdx = reg2 opnd1 = OPND_CREATE_ABSMEM((byte *)&RBufIdx, OPSZ_4); opnd2 = opnd_create_reg(reg2); instr = INSTR_CREATE_mov_st(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); dr_restore_arith_flags_from_xax(drcontext, ilist, where); dr_restore_reg(drcontext, ilist, where, reg1, SPILL_SLOT_2); dr_restore_reg(drcontext, ilist, where, reg2, SPILL_SLOT_3); }
/* * instrument_mem is called whenever a memory reference is identified. * It inserts code before the memory reference to to fill the memory buffer * and jump to our own code cache to call the clean_call when the buffer is full. */ static void instrument_mem(void *drcontext, instrlist_t *ilist, instr_t *where, int pos, bool write) { instr_t *instr, *call, *restore, *first, *second; opnd_t ref, opnd1, opnd2; reg_id_t reg1 = DR_REG_XBX; /* We can optimize it by picking dead reg */ reg_id_t reg2 = DR_REG_XCX; /* reg2 must be ECX or RCX for jecxz */ per_thread_t *data; app_pc pc; data = drmgr_get_tls_field(drcontext, tls_index); /* Steal the register for memory reference address * * We can optimize away the unnecessary register save and restore * by analyzing the code and finding the register is dead. */ dr_save_reg(drcontext, ilist, where, reg1, SPILL_SLOT_2); dr_save_reg(drcontext, ilist, where, reg2, SPILL_SLOT_3); if (write) ref = instr_get_dst(where, pos); else ref = instr_get_src(where, pos); /* use drutil to get mem address */ drutil_insert_get_mem_addr(drcontext, ilist, where, ref, reg1, reg2); /* The following assembly performs the following instructions * buf_ptr->write = write; * buf_ptr->addr = addr; * buf_ptr->size = size; * buf_ptr->pc = pc; * buf_ptr++; * if (buf_ptr >= buf_end_ptr) * clean_call(); */ drmgr_insert_read_tls_field(drcontext, tls_index, ilist, where, reg2); /* Load data->buf_ptr into reg2 */ opnd1 = opnd_create_reg(reg2); opnd2 = OPND_CREATE_MEMPTR(reg2, offsetof(per_thread_t, buf_ptr)); instr = INSTR_CREATE_mov_ld(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* Move write/read to write field */ opnd1 = OPND_CREATE_MEM32(reg2, offsetof(mem_ref_t, write)); opnd2 = OPND_CREATE_INT32(write); instr = INSTR_CREATE_mov_imm(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* Store address in memory ref */ opnd1 = OPND_CREATE_MEMPTR(reg2, offsetof(mem_ref_t, addr)); opnd2 = opnd_create_reg(reg1); instr = INSTR_CREATE_mov_st(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* Store size in memory ref */ opnd1 = OPND_CREATE_MEMPTR(reg2, offsetof(mem_ref_t, size)); /* drutil_opnd_mem_size_in_bytes handles OP_enter */ opnd2 = OPND_CREATE_INT32(drutil_opnd_mem_size_in_bytes(ref, where)); instr = INSTR_CREATE_mov_st(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* Store pc in memory ref */ pc = instr_get_app_pc(where); /* For 64-bit, we can't use a 64-bit immediate so we split pc into two halves. * We could alternatively load it into reg1 and then store reg1. * We use a convenience routine that does the two-step store for us. */ opnd1 = OPND_CREATE_MEMPTR(reg2, offsetof(mem_ref_t, pc)); instrlist_insert_mov_immed_ptrsz(drcontext, (ptr_int_t) pc, opnd1, ilist, where, &first, &second); instr_set_ok_to_mangle(first, false/*meta*/); if (second != NULL) instr_set_ok_to_mangle(second, false/*meta*/); /* Increment reg value by pointer size using lea instr */ opnd1 = opnd_create_reg(reg2); opnd2 = opnd_create_base_disp(reg2, DR_REG_NULL, 0, sizeof(mem_ref_t), OPSZ_lea); instr = INSTR_CREATE_lea(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* Update the data->buf_ptr */ drmgr_insert_read_tls_field(drcontext, tls_index, ilist, where, reg1); opnd1 = OPND_CREATE_MEMPTR(reg1, offsetof(per_thread_t, buf_ptr)); opnd2 = opnd_create_reg(reg2); instr = INSTR_CREATE_mov_st(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* we use lea + jecxz trick for better performance * lea and jecxz won't disturb the eflags, so we won't insert * code to save and restore application's eflags. */ /* lea [reg2 - buf_end] => reg2 */ opnd1 = opnd_create_reg(reg1); opnd2 = OPND_CREATE_MEMPTR(reg1, offsetof(per_thread_t, buf_end)); instr = INSTR_CREATE_mov_ld(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); opnd1 = opnd_create_reg(reg2); opnd2 = opnd_create_base_disp(reg1, reg2, 1, 0, OPSZ_lea); instr = INSTR_CREATE_lea(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* jecxz call */ call = INSTR_CREATE_label(drcontext); opnd1 = opnd_create_instr(call); instr = INSTR_CREATE_jecxz(drcontext, opnd1); instrlist_meta_preinsert(ilist, where, instr); /* jump restore to skip clean call */ restore = INSTR_CREATE_label(drcontext); opnd1 = opnd_create_instr(restore); instr = INSTR_CREATE_jmp(drcontext, opnd1); instrlist_meta_preinsert(ilist, where, instr); /* clean call */ /* We jump to lean procedure which performs full context switch and * clean call invocation. This is to reduce the code cache size. */ instrlist_meta_preinsert(ilist, where, call); /* mov restore DR_REG_XCX */ opnd1 = opnd_create_reg(reg2); /* this is the return address for jumping back from lean procedure */ opnd2 = opnd_create_instr(restore); /* We could use instrlist_insert_mov_instr_addr(), but with a register * destination we know we can use a 64-bit immediate. */ instr = INSTR_CREATE_mov_imm(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* jmp code_cache */ opnd1 = opnd_create_pc(code_cache); instr = INSTR_CREATE_jmp(drcontext, opnd1); instrlist_meta_preinsert(ilist, where, instr); /* restore %reg */ instrlist_meta_preinsert(ilist, where, restore); dr_restore_reg(drcontext, ilist, where, reg1, SPILL_SLOT_2); dr_restore_reg(drcontext, ilist, where, reg2, SPILL_SLOT_3); }
/* * instrument_mem is called whenever a memory reference is identified. * It inserts code before the memory reference to to fill the memory buffer * and jump to our own code cache to call the clean_call when the buffer is full. */ static void instrument_mem(void *drcontext, instrlist_t *ilist, instr_t *where, int pos, bool write) { instr_t *instr, *call, *restore; opnd_t ref, opnd1, opnd2; reg_id_t reg1, reg2; drvector_t allowed; per_thread_t *data; app_pc pc; data = drmgr_get_tls_field(drcontext, tls_index); /* Steal two scratch registers. * reg2 must be ECX or RCX for jecxz. */ drreg_init_and_fill_vector(&allowed, false); drreg_set_vector_entry(&allowed, DR_REG_XCX, true); if (drreg_reserve_register(drcontext, ilist, where, &allowed, ®2) != DRREG_SUCCESS || drreg_reserve_register(drcontext, ilist, where, NULL, ®1) != DRREG_SUCCESS) { DR_ASSERT(false); /* cannot recover */ drvector_delete(&allowed); return; } drvector_delete(&allowed); if (write) ref = instr_get_dst(where, pos); else ref = instr_get_src(where, pos); /* use drutil to get mem address */ drutil_insert_get_mem_addr(drcontext, ilist, where, ref, reg1, reg2); /* The following assembly performs the following instructions * buf_ptr->write = write; * buf_ptr->addr = addr; * buf_ptr->size = size; * buf_ptr->pc = pc; * buf_ptr++; * if (buf_ptr >= buf_end_ptr) * clean_call(); */ drmgr_insert_read_tls_field(drcontext, tls_index, ilist, where, reg2); /* Load data->buf_ptr into reg2 */ opnd1 = opnd_create_reg(reg2); opnd2 = OPND_CREATE_MEMPTR(reg2, offsetof(per_thread_t, buf_ptr)); instr = INSTR_CREATE_mov_ld(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* Move write/read to write field */ opnd1 = OPND_CREATE_MEM32(reg2, offsetof(mem_ref_t, write)); opnd2 = OPND_CREATE_INT32(write); instr = INSTR_CREATE_mov_imm(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* Store address in memory ref */ opnd1 = OPND_CREATE_MEMPTR(reg2, offsetof(mem_ref_t, addr)); opnd2 = opnd_create_reg(reg1); instr = INSTR_CREATE_mov_st(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* Store size in memory ref */ opnd1 = OPND_CREATE_MEMPTR(reg2, offsetof(mem_ref_t, size)); /* drutil_opnd_mem_size_in_bytes handles OP_enter */ opnd2 = OPND_CREATE_INT32(drutil_opnd_mem_size_in_bytes(ref, where)); instr = INSTR_CREATE_mov_st(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* Store pc in memory ref */ pc = instr_get_app_pc(where); /* For 64-bit, we can't use a 64-bit immediate so we split pc into two halves. * We could alternatively load it into reg1 and then store reg1. * We use a convenience routine that does the two-step store for us. */ opnd1 = OPND_CREATE_MEMPTR(reg2, offsetof(mem_ref_t, pc)); instrlist_insert_mov_immed_ptrsz(drcontext, (ptr_int_t) pc, opnd1, ilist, where, NULL, NULL); /* Increment reg value by pointer size using lea instr */ opnd1 = opnd_create_reg(reg2); opnd2 = opnd_create_base_disp(reg2, DR_REG_NULL, 0, sizeof(mem_ref_t), OPSZ_lea); instr = INSTR_CREATE_lea(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* Update the data->buf_ptr */ drmgr_insert_read_tls_field(drcontext, tls_index, ilist, where, reg1); opnd1 = OPND_CREATE_MEMPTR(reg1, offsetof(per_thread_t, buf_ptr)); opnd2 = opnd_create_reg(reg2); instr = INSTR_CREATE_mov_st(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* we use lea + jecxz trick for better performance * lea and jecxz won't disturb the eflags, so we won't insert * code to save and restore application's eflags. */ /* lea [reg2 - buf_end] => reg2 */ opnd1 = opnd_create_reg(reg1); opnd2 = OPND_CREATE_MEMPTR(reg1, offsetof(per_thread_t, buf_end)); instr = INSTR_CREATE_mov_ld(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); opnd1 = opnd_create_reg(reg2); opnd2 = opnd_create_base_disp(reg1, reg2, 1, 0, OPSZ_lea); instr = INSTR_CREATE_lea(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* jecxz call */ call = INSTR_CREATE_label(drcontext); opnd1 = opnd_create_instr(call); instr = INSTR_CREATE_jecxz(drcontext, opnd1); instrlist_meta_preinsert(ilist, where, instr); /* jump restore to skip clean call */ restore = INSTR_CREATE_label(drcontext); opnd1 = opnd_create_instr(restore); instr = INSTR_CREATE_jmp(drcontext, opnd1); instrlist_meta_preinsert(ilist, where, instr); /* clean call */ /* We jump to lean procedure which performs full context switch and * clean call invocation. This is to reduce the code cache size. */ instrlist_meta_preinsert(ilist, where, call); /* mov restore DR_REG_XCX */ opnd1 = opnd_create_reg(reg2); /* this is the return address for jumping back from lean procedure */ opnd2 = opnd_create_instr(restore); /* We could use instrlist_insert_mov_instr_addr(), but with a register * destination we know we can use a 64-bit immediate. */ instr = INSTR_CREATE_mov_imm(drcontext, opnd1, opnd2); instrlist_meta_preinsert(ilist, where, instr); /* jmp code_cache */ opnd1 = opnd_create_pc(code_cache); instr = INSTR_CREATE_jmp(drcontext, opnd1); instrlist_meta_preinsert(ilist, where, instr); /* Restore scratch registers */ instrlist_meta_preinsert(ilist, where, restore); if (drreg_unreserve_register(drcontext, ilist, where, reg1) != DRREG_SUCCESS || drreg_unreserve_register(drcontext, ilist, where, reg2) != DRREG_SUCCESS) DR_ASSERT(false); }
static reg_id_t instrument_mem(void *drcontext, instrlist_t *ilist, instr_t *where, opnd_t ref) { reg_id_t reg_ptr, reg_tmp, reg_addr; ushort type, size; bool ok; if (drreg_reserve_register(drcontext, ilist, where, NULL, ®_tmp) != DRREG_SUCCESS) { DR_ASSERT(false); return DR_REG_NULL; } if (drreg_reserve_register(drcontext, ilist, where, NULL, ®_ptr) != DRREG_SUCCESS) { DR_ASSERT(false); return DR_REG_NULL; } /* i#2449: In the situation that instrument_post_write, instrument_mem and ref all * have the same register reserved, drutil_insert_get_mem_addr will compute the * address of an operand using an incorrect register value, as drreg will elide the * save/restore. */ if (opnd_uses_reg(ref, reg_tmp) && drreg_get_app_value(drcontext, ilist, where, reg_tmp, reg_tmp) != DRREG_SUCCESS) { DR_ASSERT(false); return DR_REG_NULL; } if (opnd_uses_reg(ref, reg_ptr) && drreg_get_app_value(drcontext, ilist, where, reg_ptr, reg_ptr) != DRREG_SUCCESS) { DR_ASSERT(false); return DR_REG_NULL; } /* We use reg_ptr as scratch to get addr. Note we do this first as reg_ptr or reg_tmp * may be used in ref. */ ok = drutil_insert_get_mem_addr(drcontext, ilist, where, ref, reg_tmp, reg_ptr); DR_ASSERT(ok); drx_buf_insert_load_buf_ptr(drcontext, trace_buffer, ilist, where, reg_ptr); /* inserts memref addr */ drx_buf_insert_buf_store(drcontext, trace_buffer, ilist, where, reg_ptr, DR_REG_NULL, opnd_create_reg(reg_tmp), OPSZ_PTR, offsetof(mem_ref_t, addr)); if (IF_AARCHXX_ELSE(true, false)) { /* At this point we save the write address for later, because reg_tmp's value * will get clobbered on ARM. */ if (drreg_reserve_register(drcontext, ilist, where, NULL, ®_addr) != DRREG_SUCCESS) { DR_ASSERT(false); return DR_REG_NULL; } MINSERT(ilist, where, XINST_CREATE_move(drcontext, opnd_create_reg(reg_addr), opnd_create_reg(reg_tmp))); } /* inserts type */ type = (ushort)instr_get_opcode(where); drx_buf_insert_buf_store(drcontext, trace_buffer, ilist, where, reg_ptr, reg_tmp, OPND_CREATE_INT16(type), OPSZ_2, offsetof(mem_ref_t, type)); /* inserts size */ size = (ushort)drutil_opnd_mem_size_in_bytes(ref, where); drx_buf_insert_buf_store(drcontext, trace_buffer, ilist, where, reg_ptr, reg_tmp, OPND_CREATE_INT16(size), OPSZ_2, offsetof(mem_ref_t, size)); drx_buf_insert_update_buf_ptr(drcontext, trace_buffer, ilist, where, reg_ptr, DR_REG_NULL, sizeof(mem_ref_t)); if (instr_is_call(where)) { app_pc pc; /* Note that on ARM the call instruction writes only to the link register, so * we would never even get into instrument_mem() on ARM if this was a call. */ IF_AARCHXX(DR_ASSERT(false)); /* We simulate the call instruction's written memory by writing the next app_pc * to the written buffer, since we can't do this after the call has happened. */ drx_buf_insert_load_buf_ptr(drcontext, write_buffer, ilist, where, reg_ptr); pc = decode_next_pc(drcontext, instr_get_app_pc(where)); /* note that for a circular buffer, we don't need to specify a scratch register */ drx_buf_insert_buf_store(drcontext, trace_buffer, ilist, where, reg_ptr, DR_REG_NULL, OPND_CREATE_INTPTR((ptr_int_t)pc), OPSZ_PTR, 0); drx_buf_insert_update_buf_ptr(drcontext, write_buffer, ilist, where, reg_ptr, reg_tmp, sizeof(app_pc)); /* we don't need to persist reg_tmp to the next instruction */ if (drreg_unreserve_register(drcontext, ilist, where, reg_tmp) != DRREG_SUCCESS) DR_ASSERT(false); reg_tmp = DR_REG_NULL; } else if (IF_AARCHXX_ELSE(true, false)) { /* Now reg_tmp has the address of the write again. */ MINSERT(ilist, where, XINST_CREATE_move(drcontext, opnd_create_reg(reg_tmp), opnd_create_reg(reg_addr))); if (drreg_unreserve_register(drcontext, ilist, where, reg_addr) != DRREG_SUCCESS) DR_ASSERT(false); } if (drreg_unreserve_register(drcontext, ilist, where, reg_ptr) != DRREG_SUCCESS) DR_ASSERT(false); return reg_tmp; }