void NaClFileLockManagerLock(struct NaClFileLockManager *self,
int desc) {
struct NaClFileLockEntry key;
struct NaClFileLockEntry **existing;
struct NaClFileLockEntry *entry;
(*self->set_file_identity_data)(&key, desc);
NaClXMutexLock(&self->mu);
existing = NaClFileLockManagerFindEntryMu(self, &key);
if (NULL == existing) {
/* make new entry */
entry = NaClFileLockManagerEntryFactory(self, desc);
entry->next = self->head;
self->head = entry;
NaClXMutexUnlock(&self->mu);
} else {
entry = *existing;
NaClXMutexLock(&entry->mu);
entry->num_waiting++;
/* arithmetic overflow */
CHECK(0 != entry->num_waiting);
/* drop container lock after ensuring that the entry will not be deleted */
NaClXMutexUnlock(&self->mu);
while (entry->holding_lock) {
NaClXCondVarWait(&entry->cv, &entry->mu);
}
entry->holding_lock = 1;
entry->num_waiting--;
NaClXMutexUnlock(&entry->mu);
}
(*self->take_file_lock)(desc);
}
static void NaClManifestProxyConnectionDtor(struct NaClRefCount *vself) {
struct NaClManifestProxyConnection *self =
(struct NaClManifestProxyConnection *) vself;
NaClLog(4,
"Entered NaClManifestProxyConnectionDtor: self 0x%"NACL_PRIxPTR"\n",
(uintptr_t) self);
NaClXMutexLock(&self->mu);
while (!self->channel_initialized) {
NaClLog(4,
"NaClManifestProxyConnectionDtor:"
" waiting for connection initialization\n");
NaClXCondVarWait(&self->cv, &self->mu);
}
NaClXMutexUnlock(&self->mu);
NaClLog(4, "NaClManifestProxyConnectionDtor: dtoring\n");
NaClCondVarDtor(&self->cv);
NaClMutexDtor(&self->mu);
NaClSrpcDtor(&self->client_channel);
NACL_VTBL(NaClSimpleServiceConnection, self) =
&kNaClSimpleServiceConnectionVtbl;
(*NACL_VTBL(NaClRefCount, self)->Dtor)(vself);
}
static void NaClManifestWaitForChannel_yield_mu(
struct NaClManifestProxyConnection *self) {
NaClLog(4, "Entered NaClManifestWaitForChannel_yield_mu\n");
NaClXMutexLock(&self->mu);
NaClLog(4, "NaClManifestWaitForChannel_yield_mu: checking channel\n");
while (!self->channel_initialized) {
NaClLog(4, "NaClManifestWaitForChannel_yield_mu: waiting\n");
NaClXCondVarWait(&self->cv, &self->mu);
}
NaClLog(4, "Leaving NaClManifestWaitForChannel_yield_mu\n");
}
void NaClReverseServiceWaitForServiceThreadsToExit(
struct NaClReverseService *self) {
NaClLog(4, "NaClReverseServiceWaitForServiceThreadsToExit\n");
NaClXMutexLock(&self->mu);
while (0 != self->thread_count) {
NaClXCondVarWait(&self->cv, &self->mu);
NaClLog(5, "NaClReverseServiceWaitForServiceThreadsToExit: woke up\n");
}
NaClXMutexUnlock(&self->mu);
NaClLog(4, "NaClReverseServiceWaitForServiceThreadsToExit: all done\n");
}
NaClSyncStatus NaClIntrMutexLock(struct NaClIntrMutex *mp) {
NaClSyncStatus rv = NACL_SYNC_INTERNAL_ERROR;
NaClXMutexLock(&mp->mu);
while (NACL_INTR_LOCK_HELD == mp->lock_state) {
NaClXCondVarWait(&mp->cv, &mp->mu);
}
if (NACL_INTR_LOCK_FREE == mp->lock_state) {
mp->lock_state = NACL_INTR_LOCK_HELD;
rv = NACL_SYNC_OK;
}
if (NACL_INTR_LOCK_INTERRUPTED == mp->lock_state) {
rv = NACL_SYNC_MUTEX_INTERRUPTED;
}
NaClXMutexUnlock(&mp->mu);
return rv;
}
int NaClWaitForMainThreadToExit(struct NaClApp *nap) {
NaClLog(3, "NaClWaitForMainThreadToExit: taking NaClApp lock\n");
NaClXMutexLock(&nap->mu);
NaClLog(3, " waiting for exit status\n");
while (nap->running) {
NaClXCondVarWait(&nap->cv, &nap->mu);
NaClLog(3, " wakeup, nap->running %d, nap->exit_status %d\n",
nap->running, nap->exit_status);
}
NaClXMutexUnlock(&nap->mu);
/*
* Some thread invoked the exit (exit_group) syscall.
*/
if (NULL != nap->debug_stub_callbacks) {
nap->debug_stub_callbacks->process_exit_hook();
}
return NACL_ABI_WEXITSTATUS(nap->exit_status);
}
int NaClSimpleLtdServiceAcceptConnection(
struct NaClSimpleService *vself,
struct NaClSimpleServiceConnection **out) {
struct NaClSimpleLtdService *self =
(struct NaClSimpleLtdService *) vself;
int rv;
NaClXMutexLock(&self->mu);
while (self->num_clients >= self->max_clients) {
NaClXCondVarWait(&self->cv, &self->mu);
}
NaClXMutexUnlock(&self->mu);
/*
* Other threads can only decrement num_clients.
*/
rv = (*kNaClSimpleServiceVtbl.AcceptConnection)(vself, out);
NaClXMutexLock(&self->mu);
self->num_clients++;
NaClXMutexUnlock(&self->mu);
return rv;
}
int NaClAppLaunchServiceThreads(struct NaClApp *nap) {
struct NaClManifestProxy *manifest_proxy = NULL;
struct NaClKernelService *kernel_service = NULL;
int rv = 0;
enum NaClReverseChannelInitializationState init_state;
NaClNameServiceLaunch(nap->name_service);
kernel_service = (struct NaClKernelService *) malloc(sizeof *kernel_service);
if (NULL == kernel_service) {
NaClLog(LOG_ERROR,
"NaClAppLaunchServiceThreads: No memory for kern service\n");
goto done;
}
if (!NaClKernelServiceCtor(kernel_service,
NaClAddrSpSquattingThreadIfFactoryFunction,
(void *) nap,
nap)) {
NaClLog(LOG_ERROR,
"NaClAppLaunchServiceThreads: KernServiceCtor failed\n");
free(kernel_service);
kernel_service = NULL;
goto done;
}
if (!NaClSimpleServiceStartServiceThread((struct NaClSimpleService *)
kernel_service)) {
NaClLog(LOG_ERROR,
"NaClAppLaunchServiceThreads: KernService start service failed\n");
goto done;
}
/*
* NB: StartServiceThread grabbed another reference to kernel_service,
* used by the service thread. Closing the connection capability
* should cause the service thread to shut down and in turn release
* that reference.
*/
/*
* The locking here isn't really needed. Here is why:
* reverse_channel_initialized is written in reverse_setup RPC
* handler of the secure command channel RPC handler thread. and
* the RPC order requires that the plugin invoke reverse_setup prior
* to invoking start_module, so there will have been plenty of other
* synchronization operations to force cache coherency
* (module_may_start, for example, is set in the cache of the secure
* channel RPC handler (in start_module) and read by the main
* thread, and the synchronization operations needed to propagate
* its value properly suffices to propagate
* reverse_channel_initialized as well). However, reading it while
* holding a lock is more obviously correct for tools like tsan.
* Due to the RPC order, it is impossible for
* reverse_channel_initialized to get set after the unlock and
* before the if test.
*/
NaClXMutexLock(&nap->mu);
/*
* If no reverse_setup RPC was made, then we do not set up a
* manifest proxy. Otherwise, we make sure that the reverse channel
* setup is done, so that the application can actually use
* reverse-channel-based services such as the manifest proxy.
*/
if (NACL_REVERSE_CHANNEL_UNINITIALIZED !=
(init_state = nap->reverse_channel_initialization_state)) {
while (NACL_REVERSE_CHANNEL_INITIALIZED !=
(init_state = nap->reverse_channel_initialization_state)) {
NaClXCondVarWait(&nap->cv, &nap->mu);
}
}
NaClXMutexUnlock(&nap->mu);
if (NACL_REVERSE_CHANNEL_INITIALIZED != init_state) {
NaClLog(3,
("NaClAppLaunchServiceThreads: no reverse channel;"
" launched kernel services.\n"));
NaClLog(3,
("NaClAppLaunchServiceThreads: no reverse channel;"
" NOT launching manifest proxy.\n"));
nap->kernel_service = kernel_service;
kernel_service = NULL;
rv = 1;
goto done;
}
/*
* Allocate/construct the manifest proxy without grabbing global
* locks.
*/
NaClLog(3, "NaClAppLaunchServiceThreads: launching manifest proxy\n");
/*
* ReverseClientSetup RPC should be done via the command channel
* prior to the load_module / start_module RPCs, and
* occurs after that, so checking
* nap->reverse_client suffices for determining whether the proxy is
* exporting reverse services.
*/
manifest_proxy = (struct NaClManifestProxy *) malloc(sizeof *manifest_proxy);
if (NULL == manifest_proxy) {
NaClLog(LOG_ERROR, "No memory for manifest proxy\n");
NaClDescUnref(kernel_service->base.bound_and_cap[1]);
goto done;
}
if (!NaClManifestProxyCtor(manifest_proxy,
NaClAddrSpSquattingThreadIfFactoryFunction,
(void *) nap,
nap)) {
NaClLog(LOG_ERROR, "ManifestProxyCtor failed\n");
/* do not leave a non-NULL pointer to a not-fully constructed object */
free(manifest_proxy);
manifest_proxy = NULL;
NaClDescUnref(kernel_service->base.bound_and_cap[1]);
goto done;
}
/*
* NaClSimpleServiceStartServiceThread requires the nap->mu lock.
*/
if (!NaClSimpleServiceStartServiceThread((struct NaClSimpleService *)
manifest_proxy)) {
NaClLog(LOG_ERROR, "ManifestProxy start service failed\n");
NaClDescUnref(kernel_service->base.bound_and_cap[1]);
goto done;
}
NaClXMutexLock(&nap->mu);
CHECK(NULL == nap->manifest_proxy);
CHECK(NULL == nap->kernel_service);
nap->manifest_proxy = manifest_proxy;
manifest_proxy = NULL;
nap->kernel_service = kernel_service;
kernel_service = NULL;
NaClXMutexUnlock(&nap->mu);
rv = 1;
done:
NaClXMutexLock(&nap->mu);
if (NULL != nap->manifest_proxy) {
NaClLog(3,
("NaClAppLaunchServiceThreads: adding manifest proxy to"
" name service\n"));
(*NACL_VTBL(NaClNameService, nap->name_service)->
CreateDescEntry)(nap->name_service,
"ManifestNameService", NACL_ABI_O_RDWR,
NaClDescRef(nap->manifest_proxy->base.bound_and_cap[1]));
}
if (NULL != nap->kernel_service) {
NaClLog(3,
("NaClAppLaunchServiceThreads: adding kernel service to"
" name service\n"));
(*NACL_VTBL(NaClNameService, nap->name_service)->
CreateDescEntry)(nap->name_service,
"KernelService", NACL_ABI_O_RDWR,
NaClDescRef(nap->kernel_service->base.bound_and_cap[1]));
}
NaClXMutexUnlock(&nap->mu);
/*
* Single exit path.
*
* Error cleanup invariant. No service thread should be running
* (modulo asynchronous shutdown). Automatic variables refer to
* fully constructed objects if non-NULL, and when ownership is
* transferred to the NaClApp object the corresponding automatic
* variable is set to NULL.
*/
NaClRefCountSafeUnref((struct NaClRefCount *) manifest_proxy);
NaClRefCountSafeUnref((struct NaClRefCount *) kernel_service);
return rv;
}
int32_t NaClSysMunmap(struct NaClAppThread *natp,
void *start,
size_t length) {
int32_t retval = -NACL_ABI_EINVAL;
uintptr_t sysaddr;
int holding_app_lock = 0;
size_t alloc_rounded_length;
NaClLog(3, "Entered NaClSysMunmap(0x%08"NACL_PRIxPTR", "
"0x%08"NACL_PRIxPTR", 0x%"NACL_PRIxS")\n",
(uintptr_t) natp, (uintptr_t) start, length);
NaClSysCommonThreadSyscallEnter(natp);
if (!NaClIsAllocPageMultiple((uintptr_t) start)) {
NaClLog(4, "start addr not allocation multiple\n");
retval = -NACL_ABI_EINVAL;
goto cleanup;
}
if (0 == length) {
/*
* linux mmap of zero length yields a failure, but osx does not, leading
* to a NaClVmmapUpdate of zero pages, which should not occur.
*/
retval = -NACL_ABI_EINVAL;
goto cleanup;
}
alloc_rounded_length = NaClRoundAllocPage(length);
if (alloc_rounded_length != length) {
length = alloc_rounded_length;
NaClLog(LOG_WARNING,
"munmap: rounded length to 0x%"NACL_PRIxS"\n", length);
}
sysaddr = NaClUserToSysAddrRange(natp->nap, (uintptr_t) start, length);
if (kNaClBadAddress == sysaddr) {
NaClLog(4, "region not user addresses\n");
retval = -NACL_ABI_EFAULT;
goto cleanup;
}
NaClXMutexLock(&natp->nap->mu);
while (0 != natp->nap->threads_launching) {
NaClXCondVarWait(&natp->nap->cv, &natp->nap->mu);
}
natp->nap->vm_hole_may_exist = 1;
holding_app_lock = 1;
/*
* NB: windows (or generic) version would use Munmap virtual
* function from the backing NaClDesc object obtained by iterating
* through the address map for the region, and those Munmap virtual
* functions may return -NACL_ABI_E_MOVE_ADDRESS_SPACE.
*
* We should hold the application lock while doing this iteration
* and unmapping, so that the address space is consistent for other
* threads.
*/
/*
* User should be unable to unmap any executable pages. We check here.
*/
if (NaClSysCommonAddrRangeContainsExecutablePages_mu(natp->nap,
(uintptr_t) start,
length)) {
NaClLog(2, "NaClSysMunmap: region contains executable pages\n");
retval = -NACL_ABI_EINVAL;
goto cleanup;
}
/*
* Overwrite current mapping with inaccessible, anonymous
* zero-filled pages, which should be copy-on-write and thus
* relatively cheap. Do not open up an address space hole.
*/
NaClLog(4,
("NaClSysMunmap: mmap(0x%08"NACL_PRIxPTR", 0x%"NACL_PRIxS","
" 0x%x, 0x%x, -1, 0)\n"),
sysaddr, length, PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED);
if (MAP_FAILED == mmap((void *) sysaddr,
length,
PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
-1,
(off_t) 0)) {
NaClLog(4, "mmap to put in anonymous memory failed, errno = %d\n", errno);
retval = -NaClXlateErrno(errno);
goto cleanup;
}
NaClVmmapUpdate(&natp->nap->mem_map,
(NaClSysToUser(natp->nap, (uintptr_t) sysaddr)
>> NACL_PAGESHIFT),
length >> NACL_PAGESHIFT,
0, /* prot */
(struct NaClMemObj *) NULL,
1); /* Delete mapping */
retval = 0;
cleanup:
if (holding_app_lock) {
natp->nap->vm_hole_may_exist = 0;
NaClXCondVarBroadcast(&natp->nap->cv);
NaClXMutexUnlock(&natp->nap->mu);
}
NaClSysCommonThreadSyscallLeave(natp);
return retval;
}