diff options
Diffstat (limited to 'random/random.c')
| -rw-r--r-- | random/random.c | 41 |
1 files changed, 30 insertions, 11 deletions
diff --git a/random/random.c b/random/random.c index f926b7fd..8f76c5ba 100644 --- a/random/random.c +++ b/random/random.c @@ -143,6 +143,11 @@ trivfs_S_io_read (struct trivfs_protid *cred, data_t *data, mach_msg_type_number_t *data_len, loff_t offs, mach_msg_type_number_t amount) { + error_t err; + mach_msg_type_number_t read_amount = 0; + void *buf = NULL; + size_t length; + /* Deny access if they have bad credentials. */ if (! cred) return EOPNOTSUPP; @@ -151,21 +156,27 @@ trivfs_S_io_read (struct trivfs_protid *cred, pthread_mutex_lock (&global_lock); - if (amount > 0) + while (amount > 0) { mach_msg_type_number_t new_amount; + /* XXX: It would be nice to fix readable_pool to work for sizes + greater than the POOLSIZE. Otherwise we risk detecting too + late that we run out of entropy and all that entropy is + wasted. */ while (readable_pool (amount, level) == 0) { if (cred->po->openmodes & O_NONBLOCK) { pthread_mutex_unlock (&global_lock); - return EWOULDBLOCK; + err = EWOULDBLOCK; + goto errout; } read_blocked = 1; if (pthread_hurd_cond_wait_np (&wait, &global_lock)) { pthread_mutex_unlock (&global_lock); - return EINTR; + err = EINTR; + goto errout; } /* See term/users.c for possible race? */ } @@ -175,27 +186,35 @@ trivfs_S_io_read (struct trivfs_protid *cred, { *data = mmap (0, amount, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0); + if (*data == MAP_FAILED) { pthread_mutex_unlock (&global_lock); return errno; } - } - new_amount = read_pool ((byte *) *data, amount, level); + /* Keep track of our map in case of errors. */ + buf = *data, length = amount; - if (new_amount < amount) - munmap (*data + round_page (new_amount), - round_page(amount) - round_page (new_amount)); - amount = new_amount; + /* Update DATA_LEN to reflect the new buffers size. */ + *data_len = amount; + } + + new_amount = read_pool (((byte *) *data) + read_amount, amount, level); + read_amount += new_amount; + amount -= new_amount; } - *data_len = amount; /* Set atime, see term/users.c */ pthread_mutex_unlock (&global_lock); - + *data_len = read_amount; return 0; + + errout: + if (buf) + munmap (buf, length); + return err; } /* Write data to an IO object. If offset is -1, write at the object |