/* Our version, versus Dr. Memory's version in drmemory/fastpath.c */
bool
instr_ok_for_instrument_fastpath(instr_t *inst, fastpath_info_t *mi, bb_info_t *bi)
{
uint opc = instr_get_opcode(inst);
int i;
initialize_fastpath_info(mi, bi, inst);
if (!options.fastpath)
return false;
if (opc == OP_xlat) {
/* can't use base-disp "%ds:(%ebx,%al,1)" for lea: would have to expand
* to multiple instrs. not worth supporting since pretty rare though I
* do see 3K in twolf test on windows.
*/
return false;
}
/* We assume that any one memory reference, even in a rep string form,
* will only access one heap allocation. Since we're taking the most
* recent access to any part of a heap alloc we thus don't care about the
* size of a memory reference.
*/
for (i=0; i<instr_num_dsts(inst); i++) {
if (opnd_uses_memory_we_track(instr_get_dst(inst, i))) {
mi->store = true;
if (!opnd_is_null(mi->dst[0].app)) {
/* FIXME: we could handle 2 dsts if no srcs easily,
* and even more dsts if we really wanted to w/o too
* much trouble. also something like pusha w/
* consecutive dsts is easy: just take first one.
*/
return false;
}
mi->dst[0].app = instr_get_dst(inst, i);
}
}
for (i=0; i<instr_num_srcs(inst); i++) {
if (opnd_uses_memory_we_track(instr_get_src(inst, i))) {
if (mi->store)
mi->mem2mem = true;
else
mi->load = true;
if (!opnd_is_null(mi->src[0].app)) {
/* see notes above about handling this: in particular cmps */
return false;
}
mi->src[0].app = instr_get_src(inst, i);
}
}
return true;
}
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);
}
