void
xsi_sem_init()
{
// Initialize hash tables
status_t status = sIpcHashTable.Init();
if (status != B_OK)
panic("xsi_sem_init() failed to initialize ipc hash table\n");
status = sSemaphoreHashTable.Init();
if (status != B_OK)
panic("xsi_sem_init() failed to initialize semaphore hash table\n");
mutex_init(&sIpcLock, "global POSIX semaphore IPC table");
mutex_init(&sXsiSemaphoreSetLock, "global POSIX xsi sem table");
}
extern "C" status_t vboxsf_new_vnode(PVBSFMAP map, PSHFLSTRING path, PSHFLSTRING name, vboxsf_vnode** p) {
vboxsf_vnode* vn = (vboxsf_vnode*)malloc(sizeof(vboxsf_vnode));
if (vn == NULL) {
return B_NO_MEMORY;
}
dprintf("creating new vnode at %p with path=%p (%s)\n", vn, path->String.utf8, path->String.utf8);
vn->map = map;
vn->path = path;
if (name) {
vn->name = name;
}
else {
const char* cname = strrchr((char*)path->String.utf8, '/');
if (!cname)
vn->name = path; // no slash, assume this *is* the filename
else
vn->name = make_shflstring(cname);
}
if (mutex_lock(&g_vnodeCacheLock) < B_OK) {
free(vn);
return B_ERROR;
}
vn->vnode = g_nextVnid++;
*p = vn;
dprintf("vboxsf: allocated %p (path=%p name=%p)\n", vn, vn->path, vn->name);
status_t rv = g_cache.Insert(vn);
mutex_unlock(&g_vnodeCacheLock);
return rv;
}
extern "C" status_t vboxsf_get_vnode(fs_volume* volume, ino_t id, fs_vnode* vnode,
int* _type, uint32* _flags, bool reenter) {
vboxsf_vnode* vn = g_cache.Lookup(id);
if (vn) {
vnode->private_node = vn;
return B_OK;
}
else {
return B_ERROR;
}
}
void
XsiSemaphoreSet::SetID()
{
fID = real_time_clock();
// The lock is held before calling us
while (true) {
if (sSemaphoreHashTable.Lookup(fID) == NULL)
break;
fID = (fID + 1) % INT_MAX;
}
sGlobalSequenceNumber = (sGlobalSequenceNumber + 1) % UINT_MAX;
fSequenceNumber = sGlobalSequenceNumber;
}
int
_user_xsi_semctl(int semaphoreID, int semaphoreNumber, int command,
union semun *args)
{
TRACE(("xsi_semctl: semaphoreID = %d, semaphoreNumber = %d, command = %d\n",
semaphoreID, semaphoreNumber, command));
MutexLocker ipcHashLocker(sIpcLock);
MutexLocker setHashLocker(sXsiSemaphoreSetLock);
XsiSemaphoreSet *semaphoreSet = sSemaphoreHashTable.Lookup(semaphoreID);
if (semaphoreSet == NULL) {
TRACE_ERROR(("xsi_semctl: semaphore set id %d not valid\n",
semaphoreID));
return EINVAL;
}
if (semaphoreNumber < 0
|| semaphoreNumber > semaphoreSet->NumberOfSemaphores()) {
TRACE_ERROR(("xsi_semctl: semaphore number %d not valid for "
"semaphore %d\n", semaphoreNumber, semaphoreID));
return EINVAL;
}
if (args != 0 && !IS_USER_ADDRESS(args)) {
TRACE_ERROR(("xsi_semctl: semun address is not valid\n"));
return B_BAD_ADDRESS;
}
// Lock the semaphore set itself and release both the semaphore
// set hash table lock and the ipc hash table lock _only_ if
// the command it's not IPC_RMID, this prevents undesidered
// situation from happening while (hopefully) improving the
// concurrency.
MutexLocker setLocker;
if (command != IPC_RMID) {
setLocker.SetTo(&semaphoreSet->Lock(), false);
setHashLocker.Unlock();
ipcHashLocker.Unlock();
} else
// We are about to delete the set along with its mutex, so
// we can't use the MutexLocker class, as the mutex itself
// won't exist on function exit
mutex_lock(&semaphoreSet->Lock());
int result = 0;
XsiSemaphore *semaphore = semaphoreSet->Semaphore(semaphoreNumber);
switch (command) {
case GETVAL: {
if (!semaphoreSet->HasReadPermission()) {
TRACE_ERROR(("xsi_semctl: calling process has not permission "
"on semaphore %d, key %d\n", semaphoreSet->ID(),
(int)semaphoreSet->IpcKey()));
result = EACCES;
} else
result = semaphore->Value();
break;
}
case SETVAL: {
if (!semaphoreSet->HasPermission()) {
TRACE_ERROR(("xsi_semctl: calling process has not permission "
"on semaphore %d, key %d\n", semaphoreSet->ID(),
(int)semaphoreSet->IpcKey()));
result = EACCES;
} else {
int value;
if (user_memcpy(&value, &args->val, sizeof(int)) < B_OK) {
TRACE_ERROR(("xsi_semctl: user_memcpy failed\n"));
result = B_BAD_ADDRESS;
} else if (value > USHRT_MAX) {
TRACE_ERROR(("xsi_semctl: value %d out of range\n", value));
result = ERANGE;
} else {
semaphore->SetValue(value);
semaphoreSet->ClearUndo(semaphoreNumber);
}
}
break;
}
case GETPID: {
if (!semaphoreSet->HasReadPermission()) {
TRACE_ERROR(("xsi_semctl: calling process has not permission "
"on semaphore %d, key %d\n", semaphoreSet->ID(),
(int)semaphoreSet->IpcKey()));
result = EACCES;
} else
result = semaphore->LastPid();
break;
}
case GETNCNT: {
if (!semaphoreSet->HasReadPermission()) {
TRACE_ERROR(("xsi_semctl: calling process has not permission "
"on semaphore %d, key %d\n", semaphoreSet->ID(),
(int)semaphoreSet->IpcKey()));
result = EACCES;
} else
result = semaphore->ThreadsWaitingToIncrease();
break;
}
case GETZCNT: {
if (!semaphoreSet->HasReadPermission()) {
TRACE_ERROR(("xsi_semctl: calling process has not permission "
"on semaphore %d, key %d\n", semaphoreSet->ID(),
(int)semaphoreSet->IpcKey()));
result = EACCES;
} else
result = semaphore->ThreadsWaitingToBeZero();
break;
}
case GETALL: {
if (!semaphoreSet->HasReadPermission()) {
TRACE_ERROR(("xsi_semctl: calling process has not read "
"permission on semaphore %d, key %d\n", semaphoreSet->ID(),
(int)semaphoreSet->IpcKey()));
result = EACCES;
} else
for (int i = 0; i < semaphoreSet->NumberOfSemaphores(); i++) {
semaphore = semaphoreSet->Semaphore(i);
unsigned short value = semaphore->Value();
if (user_memcpy(&args->array[i], &value,
sizeof(unsigned short)) < B_OK) {
TRACE_ERROR(("xsi_semctl: user_memcpy failed\n"));
result = B_BAD_ADDRESS;
break;
}
}
break;
}
case SETALL: {
if (!semaphoreSet->HasPermission()) {
TRACE_ERROR(("xsi_semctl: calling process has not permission "
"on semaphore %d, key %d\n", semaphoreSet->ID(),
(int)semaphoreSet->IpcKey()));
result = EACCES;
} else {
bool doClear = true;
for (int i = 0; i < semaphoreSet->NumberOfSemaphores(); i++) {
semaphore = semaphoreSet->Semaphore(i);
unsigned short value;
if (user_memcpy(&value, &args->array[i], sizeof(unsigned short))
< B_OK) {
TRACE_ERROR(("xsi_semctl: user_memcpy failed\n"));
result = B_BAD_ADDRESS;
doClear = false;
break;
} else
semaphore->SetValue(value);
}
if (doClear)
semaphoreSet->ClearUndos();
}
break;
}
case IPC_STAT: {
if (!semaphoreSet->HasReadPermission()) {
TRACE_ERROR(("xsi_semctl: calling process has not read "
"permission on semaphore %d, key %d\n", semaphoreSet->ID(),
(int)semaphoreSet->IpcKey()));
result = EACCES;
} else {
struct semid_ds sem;
sem.sem_perm = semaphoreSet->IpcPermission();
sem.sem_nsems = semaphoreSet->NumberOfSemaphores();
sem.sem_otime = semaphoreSet->LastSemopTime();
sem.sem_ctime = semaphoreSet->LastSemctlTime();
if (user_memcpy(args->buf, &sem, sizeof(struct semid_ds))
< B_OK) {
TRACE_ERROR(("xsi_semctl: user_memcpy failed\n"));
result = B_BAD_ADDRESS;
}
}
break;
}
case IPC_SET: {
if (!semaphoreSet->HasPermission()) {
TRACE_ERROR(("xsi_semctl: calling process has not "
"permission on semaphore %d, key %d\n",
semaphoreSet->ID(), (int)semaphoreSet->IpcKey()));
result = EACCES;
} else {
struct semid_ds sem;
if (user_memcpy(&sem, args->buf, sizeof(struct semid_ds))
< B_OK) {
TRACE_ERROR(("xsi_semctl: user_memcpy failed\n"));
result = B_BAD_ADDRESS;
} else
semaphoreSet->DoIpcSet(&sem);
}
break;
}
case IPC_RMID: {
// If this was the command, we are still holding
// the semaphore set hash table lock along with the
// ipc hash table lock and the semaphore set lock
// itself, this way we are sure there is not
// one waiting in the queue of the mutex.
if (!semaphoreSet->HasPermission()) {
TRACE_ERROR(("xsi_semctl: calling process has not "
"permission on semaphore %d, key %d\n",
semaphoreSet->ID(), (int)semaphoreSet->IpcKey()));
return EACCES;
}
key_t key = semaphoreSet->IpcKey();
Ipc *ipcKey = NULL;
if (key != -1) {
ipcKey = sIpcHashTable.Lookup(key);
sIpcHashTable.Remove(ipcKey);
}
sSemaphoreHashTable.Remove(semaphoreSet);
// Wake up of threads waiting on this set
// happens in the destructor
if (key != -1)
delete ipcKey;
atomic_add(&sXsiSemaphoreCount, -semaphoreSet->NumberOfSemaphores());
atomic_add(&sXsiSemaphoreSetCount, -1);
// Remove any sem_undo request
while (struct sem_undo *entry
= semaphoreSet->GetUndoList().RemoveHead()) {
MutexLocker _(entry->team->xsi_sem_context->lock);
entry->team->xsi_sem_context->undo_list.Remove(entry);
delete entry;
}
delete semaphoreSet;
return 0;
}
default:
TRACE_ERROR(("xsi_semctl: command %d not valid\n", command));
result = EINVAL;
}
return result;
}
int
_user_xsi_semget(key_t key, int numberOfSemaphores, int flags)
{
TRACE(("xsi_semget: key = %d, numberOfSemaphores = %d, flags = %d\n",
(int)key, numberOfSemaphores, flags));
XsiSemaphoreSet *semaphoreSet = NULL;
Ipc *ipcKey = NULL;
// Default assumptions
bool isPrivate = true;
bool create = true;
MutexLocker _(sIpcLock);
if (key != IPC_PRIVATE) {
isPrivate = false;
// Check if key already exist, if it does it already has a semaphore
// set associated with it
ipcKey = sIpcHashTable.Lookup(key);
if (ipcKey == NULL) {
// The ipc key does not exist. Create it and add it to the system
if (!(flags & IPC_CREAT)) {
TRACE_ERROR(("xsi_semget: key %d does not exist, but the "
"caller did not ask for creation\n",(int)key));
return ENOENT;
}
ipcKey = new(std::nothrow) Ipc(key);
if (ipcKey == NULL) {
TRACE_ERROR(("xsi_semget: failed to create new Ipc object "
"for key %d\n", (int)key));
return ENOMEM;
}
sIpcHashTable.Insert(ipcKey);
} else {
// The IPC key exist and it already has a semaphore
if ((flags & IPC_CREAT) && (flags & IPC_EXCL)) {
TRACE_ERROR(("xsi_semget: key %d already exist\n", (int)key));
return EEXIST;
}
int semaphoreSetID = ipcKey->SemaphoreSetID();
MutexLocker _(sXsiSemaphoreSetLock);
semaphoreSet = sSemaphoreHashTable.Lookup(semaphoreSetID);
if (!semaphoreSet->HasPermission()) {
TRACE_ERROR(("xsi_semget: calling process has not permission "
"on semaphore %d, key %d\n", semaphoreSet->ID(),
(int)key));
return EACCES;
}
if (numberOfSemaphores > semaphoreSet->NumberOfSemaphores()
&& numberOfSemaphores != 0) {
TRACE_ERROR(("xsi_semget: numberOfSemaphores greater than the "
"one associated with semaphore %d, key %d\n",
semaphoreSet->ID(), (int)key));
return EINVAL;
}
create = false;
}
}
if (create) {
// Create a new sempahore set for this key
if (numberOfSemaphores <= 0
|| numberOfSemaphores >= MAX_XSI_SEMS_PER_TEAM) {
TRACE_ERROR(("xsi_semget: numberOfSemaphores out of range\n"));
return EINVAL;
}
if (sXsiSemaphoreCount >= MAX_XSI_SEMAPHORE
|| sXsiSemaphoreSetCount >= MAX_XSI_SEMAPHORE_SET) {
TRACE_ERROR(("xsi_semget: reached limit of maximum number of "
"semaphores allowed\n"));
return ENOSPC;
}
semaphoreSet = new(std::nothrow) XsiSemaphoreSet(numberOfSemaphores,
flags);
if (semaphoreSet == NULL || !semaphoreSet->InitOK()) {
TRACE_ERROR(("xsi_semget: failed to allocate a new xsi "
"semaphore set\n"));
delete semaphoreSet;
return ENOMEM;
}
atomic_add(&sXsiSemaphoreCount, numberOfSemaphores);
atomic_add(&sXsiSemaphoreSetCount, 1);
MutexLocker _(sXsiSemaphoreSetLock);
semaphoreSet->SetID();
if (isPrivate)
semaphoreSet->SetIpcKey((key_t)-1);
else {
semaphoreSet->SetIpcKey(key);
ipcKey->SetSemaphoreSetID(semaphoreSet);
}
sSemaphoreHashTable.Insert(semaphoreSet);
TRACE(("semget: new set = %d created, sequence = %ld\n",
semaphoreSet->ID(), semaphoreSet->SequenceNumber()));
}
return semaphoreSet->ID();
}
status_t
_user_xsi_semop(int semaphoreID, struct sembuf *ops, size_t numOps)
{
TRACE(("xsi_semop: semaphoreID = %d, ops = %p, numOps = %ld\n",
semaphoreID, ops, numOps));
MutexLocker setHashLocker(sXsiSemaphoreSetLock);
XsiSemaphoreSet *semaphoreSet = sSemaphoreHashTable.Lookup(semaphoreID);
if (semaphoreSet == NULL) {
TRACE_ERROR(("xsi_semop: semaphore set id %d not valid\n",
semaphoreID));
return EINVAL;
}
MutexLocker setLocker(semaphoreSet->Lock());
setHashLocker.Unlock();
if (!IS_USER_ADDRESS(ops)) {
TRACE_ERROR(("xsi_semop: sembuf address is not valid\n"));
return B_BAD_ADDRESS;
}
if (numOps < 0 || numOps >= MAX_XSI_SEMS_PER_TEAM) {
TRACE_ERROR(("xsi_semop: numOps out of range\n"));
return EINVAL;
}
struct sembuf *operations
= (struct sembuf *)malloc(sizeof(struct sembuf) * numOps);
if (operations == NULL) {
TRACE_ERROR(("xsi_semop: failed to allocate sembuf struct\n"));
return B_NO_MEMORY;
}
MemoryDeleter operationsDeleter(operations);
if (user_memcpy(operations, ops,
(sizeof(struct sembuf) * numOps)) < B_OK) {
TRACE_ERROR(("xsi_semop: user_memcpy failed\n"));
return B_BAD_ADDRESS;
}
// We won't do partial request, that is operations
// only on some sempahores belonging to the set and then
// going to sleep. If we must wait on a semaphore, we undo
// all the operations already done and go to sleep, otherwise
// we may caused some unwanted deadlock among threads
// fighting for the same set.
bool notDone = true;
status_t result = 0;
while (notDone) {
XsiSemaphore *semaphore = NULL;
short numberOfSemaphores = semaphoreSet->NumberOfSemaphores();
bool goToSleep = false;
uint32 i = 0;
for (; i < numOps; i++) {
short semaphoreNumber = operations[i].sem_num;
if (semaphoreNumber >= numberOfSemaphores) {
TRACE_ERROR(("xsi_semop: %" B_PRIu32 " invalid semaphore number"
"\n", i));
result = EINVAL;
break;
}
semaphore = semaphoreSet->Semaphore(semaphoreNumber);
unsigned short value = semaphore->Value();
short operation = operations[i].sem_op;
TRACE(("xsi_semop: semaphoreNumber = %d, value = %d\n",
semaphoreNumber, value));
if (operation < 0) {
if (semaphore->Add(operation)) {
if (operations[i].sem_flg & IPC_NOWAIT)
result = EAGAIN;
else
goToSleep = true;
break;
}
} else if (operation == 0) {
if (value == 0)
continue;
else if (operations[i].sem_flg & IPC_NOWAIT) {
result = EAGAIN;
break;
} else {
goToSleep = true;
break;
}
} else {
// Operation must be greater than zero,
// just add the value and continue
semaphore->Add(operation);
}
}
// Either we have to wait or an error occured
if (goToSleep || result != 0) {
// Undo all previously done operations
for (uint32 j = 0; j < i; j++) {
short semaphoreNumber = operations[j].sem_num;
semaphore = semaphoreSet->Semaphore(semaphoreNumber);
short operation = operations[j].sem_op;
if (operation != 0)
semaphore->Revert(operation);
}
if (result != 0)
return result;
// We have to wait: first enqueue the thread
// in the appropriate set waiting list, then
// unlock the set itself and block the thread.
bool waitOnZero = true;
if (operations[i].sem_op != 0)
waitOnZero = false;
Thread *thread = thread_get_current_thread();
queued_thread queueEntry(thread, (int32)operations[i].sem_op);
semaphore->Enqueue(&queueEntry, waitOnZero);
uint32 sequenceNumber = semaphoreSet->SequenceNumber();
TRACE(("xsi_semop: thread %d going to sleep\n", (int)thread->id));
result = semaphore->BlockAndUnlock(thread, &setLocker);
TRACE(("xsi_semop: thread %d back to life\n", (int)thread->id));
// We are back to life. Find out why!
// Make sure the set hasn't been deleted or worst yet
// replaced.
setHashLocker.Lock();
semaphoreSet = sSemaphoreHashTable.Lookup(semaphoreID);
if (result == EIDRM || semaphoreSet == NULL || (semaphoreSet != NULL
&& sequenceNumber != semaphoreSet->SequenceNumber())) {
TRACE_ERROR(("xsi_semop: semaphore set id %d (sequence = "
"%" B_PRIu32 ") got destroyed\n", semaphoreID,
sequenceNumber));
notDone = false;
result = EIDRM;
} else if (result == B_INTERRUPTED) {
TRACE_ERROR(("xsi_semop: thread %d got interrupted while "
"waiting on semaphore set id %d\n",(int)thread->id,
semaphoreID));
semaphore->Deque(&queueEntry, waitOnZero);
result = EINTR;
notDone = false;
} else {
setLocker.Lock();
setHashLocker.Unlock();
}
} else {
// everything worked like a charm (so far)
notDone = false;
TRACE(("xsi_semop: semaphore acquired succesfully\n"));
// We acquired the semaphore, now records the sem_undo
// requests
XsiSemaphore *semaphore = NULL;
uint32 i = 0;
for (; i < numOps; i++) {
short semaphoreNumber = operations[i].sem_num;
semaphore = semaphoreSet->Semaphore(semaphoreNumber);
short operation = operations[i].sem_op;
if (operations[i].sem_flg & SEM_UNDO)
if (semaphoreSet->RecordUndo(semaphoreNumber, operation)
!= B_OK) {
// Unlikely scenario, but we might get here.
// Undo everything!
// Start with semaphore operations
for (uint32 j = 0; j < numOps; j++) {
short semaphoreNumber = operations[j].sem_num;
semaphore = semaphoreSet->Semaphore(semaphoreNumber);
short operation = operations[j].sem_op;
if (operation != 0)
semaphore->Revert(operation);
}
// Remove all previously registered sem_undo request
for (uint32 j = 0; j < i; j++) {
if (operations[j].sem_flg & SEM_UNDO)
semaphoreSet->RevertUndo(operations[j].sem_num,
operations[j].sem_op);
}
result = ENOSPC;
}
}
}
}
// We did it. Set the pid of all semaphores used
if (result == 0) {
for (uint32 i = 0; i < numOps; i++) {
short semaphoreNumber = operations[i].sem_num;
XsiSemaphore *semaphore = semaphoreSet->Semaphore(semaphoreNumber);
semaphore->SetPid(getpid());
}
}
return result;
}
extern "C" status_t vboxsf_put_vnode(fs_volume* volume, fs_vnode* vnode, bool reenter) {
g_cache.Remove((vboxsf_vnode*)vnode->private_node);
}
