static INLINE void CopyCodeSafelyInitial(uint8_t *dest,
uint8_t *src,
uint32_t size,
int bundle_size) {
CopyBundleTails(dest, src, size, bundle_size);
NaClWriteMemoryBarrier();
CopyBundleHeads(dest, src, size, bundle_size);
}
static void ReplaceBundleHeadsWithHalts(uint8_t *dest,
uint32_t size,
int bundle_size) {
uint32_t *dest_ptr = (uint32_t*) dest;
uint32_t *end_ptr = (uint32_t*) (dest + size);
while (dest_ptr < end_ptr) {
/* dont assume 1-byte halt, write entire NACL_HALT_WORD */
*dest_ptr = NACL_HALT_WORD;
dest_ptr += bundle_size / sizeof(uint32_t);
}
NaClWriteMemoryBarrier();
}
static void HandleSuspendSignal(struct NaClSignalContext *regs) {
uint32_t tls_idx = NaClTlsGetIdx();
struct NaClAppThread *natp = nacl_thread[tls_idx];
struct NaClSignalContext *suspended_registers =
&natp->suspended_registers->context;
/* Sanity check. */
if (natp->suspend_state != (NACL_APP_THREAD_UNTRUSTED |
NACL_APP_THREAD_SUSPENDING)) {
NaClSignalErrorMessage("HandleSuspendSignal: "
"Unexpected suspend_state\n");
NaClAbort();
}
if (suspended_registers != NULL) {
*suspended_registers = *regs;
/*
* Ensure that the change to natp->suspend_state does not become
* visible before the change to natp->suspended_registers.
*/
NaClWriteMemoryBarrier();
}
/*
* Indicate that we have suspended by setting
* NACL_APP_THREAD_SUSPENDED. We should not need an atomic
* operation for this since the calling thread will not be trying to
* change suspend_state.
*/
natp->suspend_state |= NACL_APP_THREAD_SUSPENDED;
FutexWake(&natp->suspend_state, 1);
/* Wait until we are asked to resume. */
while (1) {
Atomic32 state = natp->suspend_state;
if ((state & NACL_APP_THREAD_SUSPENDED) != 0) {
FutexWait(&natp->suspend_state, state);
continue; /* Retry */
}
break;
}
/*
* Apply register modifications. We need to use a snapshot of
* natp->suspended_registers because, since we were asked to resume,
* we could have been asked to suspend again, and
* suspended_registers could have been allocated in the new
* suspension request but not in the original suspension request.
*/
if (suspended_registers != NULL) {
*regs = *suspended_registers;
}
}
