static dr_emit_flags_t
bb_event(void *drcontext, void *tag, instrlist_t *bb,
bool for_trace, bool translating)
{
fuzz_pass_context_t *fp;
pass_target_t *live;
if (for_trace || translating)
return DR_EMIT_DEFAULT;
/* It is ok to be racy, so hold no locks for updating. */
/* update global num_bbs */
num_total_bbs++;
/* update num_bbs for each live target */
fp = (fuzz_pass_context_t *) drmgr_get_tls_field(drcontext, tls_idx_fuzzer);
live = fp->live_targets;
if (live != NULL) {
/* XXX: the function entry basic block is not counted because the live target
* is only added on its first execution after bb_event.
*/
live->target->num_bbs++;
DRFUZZ_LOG(3, "basic block "UINT64_FORMAT_STRING" @"PFX" during fuzzing "PFX"\n",
live->target->num_bbs, tag, live->target->func_pc);
}
return DR_EMIT_DEFAULT;
}
static void
post_fuzz_handler(void *wrapcxt, void *user_data)
{
fuzz_pass_context_t *fp = (fuzz_pass_context_t *) user_data;
pass_target_t *live = fp->live_targets;
bool repeat = live->target->post_fuzz_cb(fp, (generic_func_t) live->target->func_pc);
DRFUZZ_LOG(3, "post_fuzz() for target "PFX" (%s)\n", live->target->func_pc,
repeat ? "repeat" : "stop");
if (repeat) {
dr_mcontext_t *mc = drwrap_get_mcontext(wrapcxt);
IF_DEBUG(drext_status_t redirect_status;);
/* restore the original xsp before repeating */
DRFUZZ_LOG(4, "fuzz target "PFX": restoring xsp to "PFX"\n",
live->target->func_pc, live->xsp);
mc->xsp = live->xsp;
mc->pc = live->target->func_pc;
IF_DEBUG(redirect_status =) drwrap_redirect_execution(wrapcxt);
DRFUZZ_LOG(4, "fuzz target "PFX" requesting redirect to self entry; result: %d\n",
live->target->func_pc, live->target->func_pc, redirect_status);
} else { /* the current target is finished, so pop from live stack and cache it */
static void
pre_fuzz_handler(void *wrapcxt, INOUT void **user_data)
{
void *dcontext = drwrap_get_drcontext(wrapcxt);
app_pc target_to_fuzz = drwrap_get_func(wrapcxt);
fuzz_target_t *target = hashtable_lookup(&fuzz_target_htable, target_to_fuzz);
fuzz_pass_context_t *fp = (fuzz_pass_context_t *) drmgr_get_tls_field(dcontext,
tls_idx_fuzzer);
bool is_target_entry = false;
pass_target_t *live = NULL;
dr_mcontext_t *mc;
uint i;
ASSERT(target != NULL, "pre_fuzz must be associated with a fuzz target");
DRFUZZ_LOG(3, "pre_fuzz() for target "PFX" with %d args\n",
target_to_fuzz, target->arg_count);
/* XXX i#1734: this heuristic may be incorrect when a handled fault occurs during
* the very last iteration of the last fuzz pass on any thread.
*/
clear_thread_state(fp);
/* Stop the target iterator that was captured at the last critical fault, because
* the fact that we are in pre-fuzz implies the fault was handled and doesn't matter.
*/
if (fp->thread_state->targets != NULL)
drfuzz_target_iterator_stop(fp->thread_state->targets);
/* XXX: assumes the fuzz target is never called recursively */
if (fp->live_targets != NULL && fp->live_targets->target->func_pc == target_to_fuzz) {
live = fp->live_targets; /* this is a repetition of the last live target */
} else {
is_target_entry = true; /* this is a new invocation of a target */
live = activate_cached_target(fp, target_to_fuzz); /* check the cache */
if (live == NULL)
live = create_pass_target(dcontext, wrapcxt);
live->next = fp->live_targets; /* push to live stack */
fp->live_targets = live;
}
/* required by dr_redirect_execution() (avoids having to merge the mcontext) */
mc = drwrap_get_mcontext_ex(wrapcxt, DR_MC_ALL); /* XXX: can we relax this? */
if (is_target_entry) {
live->xsp = mc->xsp;
#ifdef X86
live->unclobber.retaddr_loc = (reg_t *) mc->xsp; /* see retaddr_unclobber_t */
#endif
live->unclobber.retaddr = (reg_t) drwrap_get_retaddr(wrapcxt);
DRFUZZ_LOG(4, "fuzz target "PFX": saving stack pointer "PFX"\n",
target_to_fuzz, mc->xsp);
for (i = 0; i < target->arg_count; i++) { /* store the original arg values */
live->original_args[i] = (reg_t) drwrap_get_arg(wrapcxt, i);
/* copy original args to current args for the first iteration of the fuzz */
live->current_args[i] = live->original_args[i];
DRFUZZ_LOG(4, "fuzz target "PFX": saving original arg #%d: "PFX"\n",
target_to_fuzz, i, live->original_args[i]);
}
}
/* restore the original arg values before calling the client */
for (i = 0; i < target->arg_count; i++) {
DRFUZZ_LOG(4, "fuzz target "PFX": restoring original arg #%d: "PFX"\n",
target_to_fuzz, i, live->original_args[i]);
drwrap_set_arg(wrapcxt, i, (void *) live->original_args[i]);
}
#ifdef ARM
mc->lr = live->unclobber.retaddr; /* restore retaddr to link register */
#else /* X86 */
*live->unclobber.retaddr_loc = live->unclobber.retaddr; /* restore retaddr to stack */
#endif
target->pre_fuzz_cb(fp, (generic_func_t) target_to_fuzz, mc);
drwrap_set_mcontext(wrapcxt);
for (i = 0; i < target->arg_count; i++)
live->current_args[i] = (reg_t) drwrap_get_arg(wrapcxt, i);
*user_data = fp;
}
