diff options
| author | Parag Warudkar <pwarudkar@aol.com> | 2007-05-08 11:31:09 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 22:15:13 +0400 |
| commit | 8e39c933b1b7df501dbb68879fb1640e277b8a5c (patch) | |
| tree | 870bb5506fb670d0e44c00a7d330ee064239298b | |
| parent | 53ab97a1c1536015d4d6d900363ea96fece5ed97 (diff) | |
| download | linux-8e39c933b1b7df501dbb68879fb1640e277b8a5c.tar.xz | |
tpm: fix sleep-in-spinlock
flush_scheduled_work() can sleep, and we're calling it under spinlock.
AFAICS, moving flush_scheduled_work before spin_lock() should not cause any
problems.
Reason being - The only thing that can race against tpm_release is tpm_open
(tpm_release is called when last reference to the file is closed and only
thing that can happen after that is tpm_open??) and tpm_open acquires
driver_lock and more over it bails out with EBUSY if chip->num_opens is
greater than 0.
I also moved chip->num_pending-- to after deleting timer and setting data
pending as it looks more correct for the paranoid although it probably doesn't
matter as it is guarded by driver_lock. None the less this change should not
cause problems.
While I was at it I noticed a missing NULL check in tpm_register_hardware
which is fixed with this patch as well.
Signed-off-by: Parag Warudkar <parag.warudkar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/char/tpm/tpm.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index e5a254a434f8..ef991cd8c024 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -942,12 +942,12 @@ int tpm_release(struct inode *inode, struct file *file) { struct tpm_chip *chip = file->private_data; + flush_scheduled_work(); spin_lock(&driver_lock); file->private_data = NULL; - chip->num_opens--; del_singleshot_timer_sync(&chip->user_read_timer); - flush_scheduled_work(); atomic_set(&chip->data_pending, 0); + chip->num_opens--; put_device(chip->dev); kfree(chip->data_buffer); spin_unlock(&driver_lock); @@ -1097,8 +1097,13 @@ struct tpm_chip *tpm_register_hardware(struct device *dev, const struct tpm_vend /* Driver specific per-device data */ chip = kzalloc(sizeof(*chip), GFP_KERNEL); - if (chip == NULL) + devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL); + + if (chip == NULL || devname == NULL) { + kfree(chip); + kfree(devname); return NULL; + } init_MUTEX(&chip->buffer_mutex); init_MUTEX(&chip->tpm_mutex); @@ -1124,7 +1129,6 @@ struct tpm_chip *tpm_register_hardware(struct device *dev, const struct tpm_vend set_bit(chip->dev_num, dev_mask); - devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL); scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num); chip->vendor.miscdev.name = devname; |