static void event_attach_done(void * x) {
AttachDoneArgs * args = (AttachDoneArgs *)x;
if (context_find_from_pid(args->pid, 0) != NULL) {
args->done(ERR_ALREADY_ATTACHED, NULL, args->data);
}
else {
Context * ctx = NULL;
if (parent_ctx == NULL) {
pid_t pid = taskIdSelf();
parent_ctx = create_context(pid2id(pid, 0));
EXT(parent_ctx)->pid = pid;
parent_ctx->mem = parent_ctx;
parent_ctx->mem_access |= MEM_ACCESS_INSTRUCTION;
parent_ctx->mem_access |= MEM_ACCESS_DATA;
parent_ctx->big_endian = big_endian_host();
link_context(parent_ctx);
send_context_created_event(parent_ctx);
}
assert(parent_ctx->ref_count > 0);
ctx = create_context(pid2id(args->pid, EXT(parent_ctx)->pid));
EXT(ctx)->pid = args->pid;
EXT(ctx)->regs = (REG_SET *)loc_alloc(sizeof(REG_SET));
ctx->mem = parent_ctx;
ctx->big_endian = parent_ctx->big_endian;
(ctx->parent = parent_ctx)->ref_count++;
list_add_last(&ctx->cldl, &parent_ctx->children);
link_context(ctx);
trace(LOG_CONTEXT, "context: attached: ctx %#lx, id %#x", ctx, EXT(ctx)->pid);
send_context_created_event(ctx);
args->done(0, ctx, args->data);
if (taskIsStopped(args->pid)) {
struct event_info * info;
ctx->pending_intercept = 1;
info = event_info_alloc(EVENT_HOOK_STOP);
if (info != NULL) {
info->stopped_ctx.ctxId = args->pid;
event_info_post(info);
}
}
}
loc_free(x);
}
static void event_handler(void * arg) {
struct event_info * info = (struct event_info *)arg;
Context * current_ctx = context_find_from_pid(info->current_ctx.ctxId, 1);
Context * stopped_ctx = context_find_from_pid(info->stopped_ctx.ctxId, 1);
switch (info->event) {
case EVENT_HOOK_BREAKPOINT:
if (stopped_ctx == NULL) break;
assert(!stopped_ctx->stopped);
assert(!EXT(stopped_ctx)->regs_dirty);
if (EXT(stopped_ctx)->regs_error) {
release_error_report(EXT(stopped_ctx)->regs_error);
EXT(stopped_ctx)->regs_error = NULL;
}
memcpy(EXT(stopped_ctx)->regs, &info->regs, sizeof(REG_SET));
EXT(stopped_ctx)->event = 0;
stopped_ctx->signal = SIGTRAP;
stopped_ctx->stopped = 1;
stopped_ctx->stopped_by_bp = info->bp_info_ok;
stopped_ctx->stopped_by_exception = 0;
assert(get_regs_PC(stopped_ctx) == info->addr);
if (stopped_ctx->stopped_by_bp && !is_breakpoint_address(stopped_ctx, info->addr)) {
/* Break instruction that is not planted by us */
stopped_ctx->stopped_by_bp = 0;
stopped_ctx->pending_intercept = 1;
}
EXT(stopped_ctx)->bp_info = info->bp_info;
if (current_ctx != NULL) EXT(stopped_ctx)->bp_pid = EXT(current_ctx)->pid;
assert(taskIsStopped(EXT(stopped_ctx)->pid));
trace(LOG_CONTEXT, "context: stopped by breakpoint: ctx %#lx, id %#x",
stopped_ctx, EXT(stopped_ctx)->pid);
send_context_stopped_event(stopped_ctx);
break;
case EVENT_HOOK_STEP_DONE:
if (current_ctx == NULL) break;
assert(!current_ctx->stopped);
assert(!EXT(current_ctx)->regs_dirty);
if (EXT(current_ctx)->regs_error) {
release_error_report(EXT(current_ctx)->regs_error);
EXT(current_ctx)->regs_error = NULL;
}
memcpy(EXT(current_ctx)->regs, &info->regs, sizeof(REG_SET));
EXT(current_ctx)->event = TRACE_EVENT_STEP;
current_ctx->signal = SIGTRAP;
current_ctx->stopped = 1;
current_ctx->stopped_by_bp = 0;
current_ctx->stopped_by_exception = 0;
assert(taskIsStopped(EXT(current_ctx)->pid));
trace(LOG_CONTEXT, "context: stopped by end of step: ctx %#lx, id %#x",
current_ctx, EXT(current_ctx)->pid);
send_context_stopped_event(current_ctx);
break;
case EVENT_HOOK_STOP:
if (stopped_ctx == NULL) break;
assert(!stopped_ctx->exited);
if (stopped_ctx->stopped) break;
if (EXT(stopped_ctx)->regs_error) {
release_error_report(EXT(stopped_ctx)->regs_error);
EXT(stopped_ctx)->regs_error = NULL;
}
if (taskRegsGet(EXT(stopped_ctx)->pid, EXT(stopped_ctx)->regs) != OK) {
EXT(stopped_ctx)->regs_error = get_error_report(errno);
assert(EXT(stopped_ctx)->regs_error != NULL);
}
EXT(stopped_ctx)->event = 0;
stopped_ctx->signal = SIGSTOP;
stopped_ctx->stopped = 1;
stopped_ctx->stopped_by_bp = 0;
stopped_ctx->stopped_by_exception = 0;
assert(taskIsStopped(EXT(stopped_ctx)->pid));
trace(LOG_CONTEXT, "context: stopped by sofware request: ctx %#lx, id %#x",
stopped_ctx, EXT(stopped_ctx)->pid);
send_context_stopped_event(stopped_ctx);
break;
case EVENT_HOOK_TASK_ADD:
if (current_ctx == NULL) break;
assert(stopped_ctx == NULL);
stopped_ctx = create_context(pid2id((pid_t)info->stopped_ctx.ctxId, EXT(current_ctx->parent)->pid));
EXT(stopped_ctx)->pid = (pid_t)info->stopped_ctx.ctxId;
EXT(stopped_ctx)->regs = (REG_SET *)loc_alloc(sizeof(REG_SET));
stopped_ctx->mem = current_ctx->mem;
stopped_ctx->big_endian = current_ctx->mem->big_endian;
(stopped_ctx->creator = current_ctx)->ref_count++;
(stopped_ctx->parent = current_ctx->parent)->ref_count++;
assert(stopped_ctx->mem == stopped_ctx->parent->mem);
list_add_last(&stopped_ctx->cldl, &stopped_ctx->parent->children);
link_context(stopped_ctx);
trace(LOG_CONTEXT, "context: created: ctx %#lx, id %#x",
stopped_ctx, EXT(stopped_ctx)->pid);
send_context_created_event(stopped_ctx);
break;
default:
assert(0);
break;
}
loc_free(info);
SPIN_LOCK_ISR_TAKE(&events_lock);
events_cnt--;
SPIN_LOCK_ISR_GIVE(&events_lock);
}
static void event_pid_stopped(pid_t pid, int signal, int event, int syscall) {
int stopped_by_exception = 0;
unsigned long msg = 0;
Context * ctx = NULL;
Context * ctx2 = NULL;
trace(LOG_EVENTS, "event: pid %d stopped, signal %d", pid, signal);
ctx = context_find_from_pid(pid, 1);
if (ctx == NULL) {
ctx = find_pending(pid);
if (ctx != NULL) {
Context * prs = ctx;
assert(prs->ref_count == 0);
ctx = create_context(pid2id(pid, pid));
EXT(ctx)->pid = pid;
EXT(ctx)->regs = (REG_SET *)loc_alloc(sizeof(REG_SET));
ctx->pending_intercept = 1;
ctx->mem = prs;
ctx->parent = prs;
ctx->big_endian = prs->big_endian;
prs->ref_count++;
list_add_last(&ctx->cldl, &prs->children);
link_context(prs);
link_context(ctx);
send_context_created_event(prs);
send_context_created_event(ctx);
if (EXT(prs)->attach_callback) {
EXT(prs)->attach_callback(0, prs, EXT(prs)->attach_data);
EXT(prs)->attach_callback = NULL;
EXT(prs)->attach_data = NULL;
}
}
}
if (ctx == NULL) return;
assert(!ctx->exited);
assert(!EXT(ctx)->attach_callback);
if (signal != SIGSTOP && signal != SIGTRAP) {
sigset_set(&ctx->pending_signals, signal, 1);
if (sigset_get(&ctx->sig_dont_stop, signal) == 0) {
ctx->pending_intercept = 1;
stopped_by_exception = 1;
}
}
if (ctx->stopped) {
send_context_changed_event(ctx);
}
else {
thread_state_t state;
unsigned int state_count;
ContextAddress pc0 = 0;
ContextAddress pc1 = 0;
assert(!EXT(ctx)->regs_dirty);
EXT(ctx)->end_of_step = 0;
EXT(ctx)->ptrace_event = event;
ctx->signal = signal;
ctx->stopped_by_bp = 0;
ctx->stopped_by_exception = stopped_by_exception;
ctx->stopped = 1;
if (EXT(ctx)->regs_error) {
release_error_report(EXT(ctx)->regs_error);
EXT(ctx)->regs_error = NULL;
}
else {
pc0 = get_regs_PC(ctx);
}
if (thread_get_state(EXT(ctx)->pid, x86_THREAD_STATE32, EXT(ctx)->regs, &state_count) != KERN_SUCCESS) {
assert(errno != 0);
EXT(ctx)->regs_error = get_error_report(errno);
trace(LOG_ALWAYS, "error: thread_get_state failed; id %s, error %d %s",
ctx->id, errno, errno_to_str(errno));
}
else {
pc1 = get_regs_PC(ctx);
}
if (!EXT(ctx)->syscall_enter || EXT(ctx)->regs_error || pc0 != pc1) {
EXT(ctx)->syscall_enter = 0;
EXT(ctx)->syscall_exit = 0;
EXT(ctx)->syscall_id = 0;
EXT(ctx)->syscall_pc = 0;
}
trace(LOG_EVENTS, "event: pid %d stopped at PC = %#lx", pid, pc1);
if (signal == SIGTRAP && event == 0 && !syscall) {
size_t break_size = 0;
get_break_instruction(ctx, &break_size);
ctx->stopped_by_bp = !EXT(ctx)->regs_error && is_breakpoint_address(ctx, pc1 - break_size);
EXT(ctx)->end_of_step = !ctx->stopped_by_bp && EXT(ctx)->pending_step;
if (ctx->stopped_by_bp) set_regs_PC(ctx, pc1 - break_size);
}
EXT(ctx)->pending_step = 0;
send_context_stopped_event(ctx);
}
}
static void event_pid_stopped(pid_t pid, int signal, int event, int syscall) {
int stopped_by_exception = 0;
Context * ctx = NULL;
trace(LOG_EVENTS, "event: pid %d stopped, signal %d, event %s", pid, signal, event_name(event));
ctx = context_find_from_pid(pid, 1);
if (ctx == NULL) {
ctx = find_pending(pid);
if (ctx != NULL) {
Context * prs = ctx;
assert(prs->ref_count == 0);
ctx = create_context(pid2id(pid, pid));
EXT(ctx)->pid = pid;
EXT(ctx)->regs = (REG_SET *)loc_alloc(sizeof(REG_SET));
ctx->pending_intercept = 1;
ctx->mem = prs;
ctx->parent = prs;
ctx->big_endian = prs->big_endian;
prs->ref_count++;
list_add_last(&ctx->cldl, &prs->children);
link_context(prs);
link_context(ctx);
send_context_created_event(prs);
send_context_created_event(ctx);
if (EXT(prs)->attach_callback) {
EXT(prs)->attach_callback(0, prs, EXT(prs)->attach_data);
EXT(prs)->attach_callback = NULL;
EXT(prs)->attach_data = NULL;
}
}
}
if (ctx == NULL) return;
assert(!ctx->exited);
assert(!EXT(ctx)->attach_callback);
if (signal != SIGSTOP && signal != SIGTRAP) {
assert(signal < 32);
ctx->pending_signals |= 1 << signal;
if ((ctx->sig_dont_stop & (1 << signal)) == 0) {
ctx->pending_intercept = 1;
stopped_by_exception = 1;
}
}
if (ctx->stopped) {
send_context_changed_event(ctx);
}
else {
ContextAddress pc0 = 0;
ContextAddress pc1 = 0;
assert(!EXT(ctx)->regs_dirty);
EXT(ctx)->end_of_step = 0;
EXT(ctx)->ptrace_event = event;
ctx->signal = signal;
ctx->stopped_by_bp = 0;
ctx->stopped_by_exception = stopped_by_exception;
ctx->stopped = 1;
if (EXT(ctx)->regs_error) {
release_error_report(EXT(ctx)->regs_error);
EXT(ctx)->regs_error = NULL;
}
else {
pc0 = get_regs_PC(ctx);
}
if (ptrace(PTRACE_GETREGS, EXT(ctx)->pid, 0, (int)EXT(ctx)->regs) < 0) {
assert(errno != 0);
if (errno == ESRCH) {
/* Racing condition: somebody resumed this context while we are handling stop event.
*
* One possible cause: main thread has exited forcing children to exit too.
* I beleive it is a bug in PTRACE implementation - PTRACE should delay exiting of
* a context while it is stopped, but it does not, which causes a nasty racing.
*
* Workaround: Ignore current event, assume context is running.
*/
ctx->stopped = 0;
return;
}
EXT(ctx)->regs_error = get_error_report(errno);
trace(LOG_ALWAYS, "error: ptrace(PTRACE_GETREGS) failed; id %s, error %d %s",
ctx->id, errno, errno_to_str(errno));
}
else {
pc1 = get_regs_PC(ctx);
}
trace(LOG_EVENTS, "event: pid %d stopped at PC = %#lx", pid, pc1);
if (signal == SIGTRAP && event == 0 && !syscall) {
size_t break_size = 0;
get_break_instruction(ctx, &break_size);
ctx->stopped_by_bp = !EXT(ctx)->regs_error && is_breakpoint_address(ctx, pc1 - break_size);
EXT(ctx)->end_of_step = !ctx->stopped_by_bp && EXT(ctx)->pending_step;
if (ctx->stopped_by_bp) set_regs_PC(ctx, pc1 - break_size);
}
EXT(ctx)->pending_step = 0;
send_context_stopped_event(ctx);
}
}