drcovlib_status_t
drcovlib_init(drcovlib_options_t *ops)
{
int count = dr_atomic_add32_return_sum(&drcovlib_init_count, 1);
if (count > 1)
return DRCOVLIB_SUCCESS;
if (ops->struct_size != sizeof(options))
return DRCOVLIB_ERROR_INVALID_PARAMETER;
if ((ops->flags & (~(DRCOVLIB_DUMP_AS_TEXT|DRCOVLIB_THREAD_PRIVATE))) != 0)
return DRCOVLIB_ERROR_INVALID_PARAMETER;
if (TEST(DRCOVLIB_THREAD_PRIVATE, ops->flags)) {
if (!dr_using_all_private_caches())
return DRCOVLIB_ERROR_INVALID_SETUP;
drcov_per_thread = true;
}
options = *ops;
if (options.logdir != NULL)
dr_snprintf(logdir, BUFFER_SIZE_ELEMENTS(logdir), "%s", ops->logdir);
else /* default */
dr_snprintf(logdir, BUFFER_SIZE_ELEMENTS(logdir), ".");
NULL_TERMINATE_BUFFER(logdir);
options.logdir = logdir;
if (options.native_until_thread > 0)
go_native = true;
drmgr_init();
drx_init();
/* We follow a simple model of the caller requesting the coverage dump,
* either via calling the exit routine, using its own soft_kills nudge, or
* an explicit dump call for unusual cases. This means that drx's
* soft_kills remains inside the outer later, i.e., the drcov client. This
* is the easiest approach for coordinating soft_kills among many libraries.
* Thus, we do *not* register for an exit event here.
*/
drmgr_register_thread_init_event(event_thread_init);
drmgr_register_thread_exit_event(event_thread_exit);
drmgr_register_bb_instrumentation_event(event_basic_block_analysis, NULL, NULL);
dr_register_filter_syscall_event(event_filter_syscall);
drmgr_register_pre_syscall_event(event_pre_syscall);
#ifdef UNIX
dr_register_fork_init_event(event_fork);
#endif
tls_idx = drmgr_register_tls_field();
if (tls_idx == -1)
return DRCOVLIB_ERROR;
return event_init();
}
static void
insert_counter_update(void *drcontext, instrlist_t *bb, instr_t *where, int offset)
{
/* Since the inc instruction clobbers 5 of the arithmetic eflags,
* we have to save them around the inc. We could be more efficient
* by not bothering to save the overflow flag and constructing our
* own sequence of instructions to save the other 5 flags (using
* lahf).
*/
if (drreg_reserve_aflags(drcontext, bb, where) != DRREG_SUCCESS) {
DR_ASSERT(false); /* cannot recover */
return;
}
/* Increment the global counter using the lock prefix to make it atomic
* across threads. It would be cheaper to aggregate the thread counters
* in the exit events, but this sample is intended to illustrate inserted
* instrumentation.
*/
instrlist_meta_preinsert(
bb, where,
LOCK(INSTR_CREATE_inc(
drcontext, OPND_CREATE_ABSMEM(((byte *)&global_count) + offset, OPSZ_4))));
/* Increment the thread private counter. */
if (dr_using_all_private_caches()) {
per_thread_t *data = (per_thread_t *)drmgr_get_tls_field(drcontext, tls_idx);
/* private caches - we can use an absolute address */
instrlist_meta_preinsert(
bb, where,
INSTR_CREATE_inc(drcontext,
OPND_CREATE_ABSMEM(((byte *)&data) + offset, OPSZ_4)));
} else {
/* shared caches - we must indirect via thread local storage */
reg_id_t scratch;
if (drreg_reserve_register(drcontext, bb, where, NULL, &scratch) != DRREG_SUCCESS)
DR_ASSERT(false);
drmgr_insert_read_tls_field(drcontext, tls_idx, bb, where, scratch);
instrlist_meta_preinsert(
bb, where, INSTR_CREATE_inc(drcontext, OPND_CREATE_MEM32(scratch, offset)));
if (drreg_unreserve_register(drcontext, bb, where, scratch) != DRREG_SUCCESS)
DR_ASSERT(false);
}
if (drreg_unreserve_aflags(drcontext, bb, where) != DRREG_SUCCESS)
DR_ASSERT(false); /* cannot recover */
}
static void
insert_counter_update(void *drcontext, instrlist_t *bb, instr_t *where, int offset)
{
/* Since the inc instruction clobbers 5 of the arithmetic eflags,
* we have to save them around the inc. We could be more efficient
* by not bothering to save the overflow flag and constructing our
* own sequence of instructions to save the other 5 flags (using
* lahf) or by doing a liveness analysis on the flags and saving
* only if live.
*/
dr_save_reg(drcontext, bb, where, DR_REG_XAX, SPILL_SLOT_1);
dr_save_arith_flags_to_xax(drcontext, bb, where);
/* Increment the global counter using the lock prefix to make it atomic
* across threads. It would be cheaper to aggregate the thread counters
* in the exit events, but this sample is intended to illustrate inserted
* instrumentation.
*/
instrlist_meta_preinsert(bb, where, LOCK(INSTR_CREATE_inc
(drcontext, OPND_CREATE_ABSMEM(((byte *)&global_count) + offset, OPSZ_4))));
/* Increment the thread private counter. */
if (dr_using_all_private_caches()) {
per_thread_t *data = (per_thread_t *) dr_get_tls_field(drcontext);
/* private caches - we can use an absolute address */
instrlist_meta_preinsert(bb, where, INSTR_CREATE_inc(drcontext,
OPND_CREATE_ABSMEM(((byte *)&data) + offset, OPSZ_4)));
} else {
/* shared caches - we must indirect via thread local storage */
/* We spill xbx to use a scratch register (we could do a liveness
* analysis to try and find a dead register to use). Note that xax
* is currently holding the saved eflags. */
dr_save_reg(drcontext, bb, where, DR_REG_XBX, SPILL_SLOT_2);
dr_insert_read_tls_field(drcontext, bb, where, DR_REG_XBX);
instrlist_meta_preinsert(bb, where,
INSTR_CREATE_inc(drcontext, OPND_CREATE_MEM32(DR_REG_XBX, offset)));
dr_restore_reg(drcontext, bb, where, DR_REG_XBX, SPILL_SLOT_2);
}
/* Restore flags and xax. */
dr_restore_arith_flags_from_xax(drcontext, bb, where);
dr_restore_reg(drcontext, bb, where, DR_REG_XAX, SPILL_SLOT_1);
}