From 8e39c933b1b7df501dbb68879fb1640e277b8a5c Mon Sep 17 00:00:00 2001 From: Parag Warudkar Date: Tue, 8 May 2007 00:31:09 -0700 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/tpm/tpm.c | 12 ++++++++---- 1 file 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; -- GitLab