static
dr_signal_action_t signal_event_redirect(void *dcontext, dr_siginfo_t *info)
{
if (info->sig == SIGSEGV) {
app_pc addr;
module_data_t *data = dr_lookup_module_by_name("client."EVENTS);
dr_fprintf(STDERR, "signal event redirect\n");
if (data == NULL) {
dr_fprintf(STDERR, "couldn't find client."EVENTS" module\n");
return DR_SIGNAL_DELIVER;
}
addr = (app_pc)dr_get_proc_address(data->handle, "redirect");
dr_free_module_data(data);
if (addr == NULL) {
dr_fprintf(STDERR, "Couldn't find function redirect in client."EVENTS"\n");
return DR_SIGNAL_DELIVER;
}
#ifdef X64
/* align properly in case redirect function relies on conventions (i#384) */
info->mcontext->xsp = ALIGN_BACKWARD(info->mcontext->xsp, 16) - sizeof(void*);
#endif
info->mcontext->pc = addr;
return DR_SIGNAL_REDIRECT;
}
return DR_SIGNAL_DELIVER;
}
static
bool exception_event_redirect(void *dcontext, dr_exception_t *excpt)
{
app_pc addr;
dr_mcontext_t mcontext = {sizeof(mcontext),DR_MC_ALL,};
module_data_t *data = dr_lookup_module_by_name("client."EVENTS".exe");
dr_fprintf(STDERR, "exception event redirect\n");
if (data == NULL) {
dr_fprintf(STDERR, "couldn't find "EVENTS".exe module\n");
return true;
}
addr = (app_pc)dr_get_proc_address(data->handle, "redirect");
dr_free_module_data(data);
mcontext = *excpt->mcontext;
mcontext.pc = addr;
if (addr == NULL) {
dr_fprintf(STDERR, "Couldn't find function redirect in "EVENTS".exe\n");
return true;
}
#ifdef X64
/* align properly in case redirect function relies on conventions (i#419) */
mcontext.xsp = ALIGN_BACKWARD(mcontext.xsp, 16) - sizeof(void*);
#endif
dr_redirect_execution(&mcontext);
dr_fprintf(STDERR, "should not be reached, dr_redirect_execution() should not return\n");
return true;
}
static int
get_sysnum(const char *wrapper)
{
byte *entry;
module_data_t *data = dr_lookup_module_by_name("ntdll.dll");
ASSERT(data != NULL);
entry = (byte *) dr_get_proc_address(data->handle, wrapper);
dr_free_module_data(data);
if (entry == NULL)
return -1;
return drmgr_decode_sysnum_from_wrapper(entry);
}
app_pc
get_ntdll_base(void)
{
static app_pc ntdll_base; /* cached value */
if (ntdll_base == NULL) {
module_data_t *data = dr_lookup_module_by_name("ntdll.dll");
ASSERT(data != NULL, "cannot find ntdll.dll");
ntdll_base = data->start;
dr_free_module_data(data);
ASSERT(ntdll_base != NULL, "internal error finding ntdll.dll base");
}
return ntdll_base;
}
static int
get_write_sysnum(void)
{
#ifdef LINUX
return SYS_write;
#else
byte *entry;
module_data_t *data = dr_lookup_module_by_name("ntdll.dll");
DR_ASSERT(data != NULL);
entry = (byte *) dr_get_proc_address(data->handle, "NtWriteFile");
DR_ASSERT(entry != NULL);
dr_free_module_data(data);
return drmgr_decode_sysnum_from_wrapper(entry);
#endif
}
DR_EXPORT
void dr_init(client_id_t id)
{
module_data_t *data;
dr_fprintf(STDERR, "thank you for testing the client interface\n");
dr_register_bb_event(bb_event);
data = dr_lookup_module_by_name("kernel32.dll");
if (data != NULL) {
exit_proc_addr = (void *)dr_get_proc_address(data->handle, "ExitProcess");
if (exit_proc_addr == NULL)
dr_fprintf(STDERR, "ERROR: unable to find kernel32!ExitProcess\n");
dr_free_module_data(data);
} else {
dr_fprintf(STDERR, "ERROR: unable to find ntdll.dll\n");
}
}
static bool
drmgr_cls_init(void)
{
/* For callback init we watch for KiUserCallbackDispatcher.
* For callback exit we watch for NtCallbackReturn or int 0x2b.
*/
static int cls_initialized; /* 0=not tried; >0=success; <0=failure */
module_data_t *data;
module_handle_t ntdll_lib;
app_pc addr_cbret;
drmgr_priority_t priority = {sizeof(priority), "drmgr_cls", NULL, NULL, 0};
if (cls_initialized > 0)
return true;
else if (cls_initialized < 0)
return false;
cls_initialized = -1;
if (!drmgr_register_bb_instrumentation_event(drmgr_event_bb_analysis,
drmgr_event_bb_insert,
&priority))
return false;
dr_register_filter_syscall_event(drmgr_event_filter_syscall);
data = dr_lookup_module_by_name("ntdll.dll");
if (data == NULL) {
/* fatal error: something is really wrong w/ underlying DR */
return false;
}
ntdll_lib = data->handle;
dr_free_module_data(data);
addr_KiCallback = (app_pc) dr_get_proc_address(ntdll_lib, "KiUserCallbackDispatcher");
if (addr_KiCallback == NULL)
return false; /* should not happen */
/* the wrapper is not good enough for two reasons: one, we want to swap
* contexts at the last possible moment, not prior to executing a few
* instrs; second, we'll miss hand-rolled syscalls
*/
addr_cbret = (app_pc) dr_get_proc_address(ntdll_lib, "NtCallbackReturn");
if (addr_cbret == NULL)
return false; /* should not happen */
sysnum_NtCallbackReturn = drmgr_decode_sysnum_from_wrapper(addr_cbret);
if (sysnum_NtCallbackReturn == -1)
return false; /* should not happen */
cls_initialized = 1;
return true;
}
static int
get_write_sysnum(void)
{
/* XXX: we could use the "drsyscall" Extension from the Dr. Memory Framework
* (DRMF) to obtain the number of any system call from the name.
*/
#ifdef UNIX
return SYS_write;
#else
byte *entry;
module_data_t *data = dr_lookup_module_by_name("ntdll.dll");
DR_ASSERT(data != NULL);
entry = (byte *) dr_get_proc_address(data->handle, "NtWriteFile");
DR_ASSERT(entry != NULL);
dr_free_module_data(data);
return drmgr_decode_sysnum_from_wrapper(entry);
#endif
}
DR_EXPORT
void dr_init(client_id_t id)
{
/* Look up start_instrument() and stop_instrument() in the app.
* These functions are markers that tell us when to start and stop
* instrumenting.
*/
module_data_t *prog = dr_lookup_module_by_name("client.cbr4.exe");
ASSERT(prog != NULL);
start_pc = (app_pc)dr_get_proc_address(prog->handle, "start_instrument");
stop_pc = (app_pc)dr_get_proc_address(prog->handle, "stop_instrument");
ASSERT(start_pc != NULL && stop_pc != NULL);
dr_free_module_data(prog);
table = new_table();
dr_register_bb_event(bb_event);
dr_register_exit_event(dr_exit);
}
static
dr_signal_action_t signal_event_redirect(void *dcontext, dr_siginfo_t *info)
{
if (info->sig == SIGSEGV) {
app_pc addr;
module_data_t *data = dr_lookup_module_by_name("client.events");
dr_fprintf(STDERR, "signal event redirect\n");
if (data == NULL) {
dr_fprintf(STDERR, "couldn't find client.events module\n");
return DR_SIGNAL_DELIVER;
}
addr = (app_pc)dr_get_proc_address(data->handle, "redirect");
dr_free_module_data(data);
if (addr == NULL) {
dr_fprintf(STDERR, "Couldn't find function redirect in client.events\n");
return DR_SIGNAL_DELIVER;
}
info->mcontext->pc = addr;
return DR_SIGNAL_REDIRECT;
}
return DR_SIGNAL_DELIVER;
}
DR_EXPORT
drmf_status_t
drsymcache_init(client_id_t client_id,
const char *symcache_dir_in,
size_t modsize_cache_threshold)
{
#ifdef WINDOWS
module_data_t *mod;
#endif
drmf_status_t res;
drmgr_priority_t pri_mod_load_cache =
{sizeof(pri_mod_load_cache), DRMGR_PRIORITY_NAME_DRSYMCACHE, NULL, NULL,
DRMGR_PRIORITY_MODLOAD_DRSYMCACHE_READ};
drmgr_priority_t pri_mod_unload_cache =
{sizeof(pri_mod_unload_cache), DRMGR_PRIORITY_NAME_DRSYMCACHE, NULL, NULL,
DRMGR_PRIORITY_MODUNLOAD_DRSYMCACHE};
drmgr_priority_t pri_mod_save_cache =
{sizeof(pri_mod_save_cache), DRMGR_PRIORITY_NAME_DRSYMCACHE_SAVE, NULL, NULL,
DRMGR_PRIORITY_MODLOAD_DRSYMCACHE_SAVE};
/* handle multiple sets of init/exit calls */
int count = dr_atomic_add32_return_sum(&symcache_init_count, 1);
if (count > 1)
return DRMF_WARNING_ALREADY_INITIALIZED;
res = drmf_check_version(client_id);
if (res != DRMF_SUCCESS)
return res;
drmgr_init();
drmgr_register_module_load_event_ex(symcache_module_load, &pri_mod_load_cache);
drmgr_register_module_unload_event_ex(symcache_module_unload, &pri_mod_unload_cache);
drmgr_register_module_load_event_ex(symcache_module_load_save, &pri_mod_save_cache);
initialized = true;
op_modsize_cache_threshold = modsize_cache_threshold;
hashtable_init_ex(&symcache_table, SYMCACHE_MASTER_TABLE_HASH_BITS,
IF_WINDOWS_ELSE(HASH_STRING_NOCASE, HASH_STRING),
true/*strdup*/, false/*!synch*/,
symcache_free_entry, NULL, NULL);
symcache_lock = dr_mutex_create();
dr_snprintf(symcache_dir, BUFFER_SIZE_ELEMENTS(symcache_dir),
"%s", symcache_dir_in);
NULL_TERMINATE_BUFFER(symcache_dir);
if (!dr_directory_exists(symcache_dir)) {
if (!dr_create_dir(symcache_dir)) {
/* check again in case of a race (i#616) */
if (!dr_directory_exists(symcache_dir)) {
NOTIFY_ERROR("Unable to create symcache dir %s"NL, symcache_dir);
ASSERT(false, "unable to create symcache dir");
dr_abort();
}
}
}
#ifdef WINDOWS
/* It's common for tools to query ntdll in their init routines so we add it
* early here
*/
mod = dr_lookup_module_by_name("ntdll.dll");
if (mod != NULL) {
symcache_module_load(dr_get_current_drcontext(), mod, true);
dr_free_module_data(mod);
}
#endif
return DRMF_SUCCESS;
}
