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Protect tpm_chip_list when transversing it.

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Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Morris <jmorris@namei.org>
This commit is contained in:
Rajiv Andrade 2008-10-11 09:04:23 +11:00 committed by James Morris
parent dc36d32cc5
commit f02a93645e
1 changed files with 24 additions and 37 deletions
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61
drivers/char/tpm/tpm.c
View file

@ -961,33 +961,28 @@ EXPORT_SYMBOL_GPL(tpm_store_cancel);
*/
int tpm_open(struct inode *inode, struct file *file)
{
int rc = 0, minor = iminor(inode);
int minor = iminor(inode);
struct tpm_chip *chip = NULL, *pos;
spin_lock(&driver_lock);
list_for_each_entry(pos, &tpm_chip_list, list) {
rcu_read_lock();
list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
if (pos->vendor.miscdev.minor == minor) {
chip = pos;
get_device(chip->dev);
break;
}
}
rcu_read_unlock();
if (chip == NULL) {
rc = -ENODEV;
goto err_out;
}
if (!chip)
return -ENODEV;
if (test_and_set_bit(0, &chip->is_open)) {
dev_dbg(chip->dev, "Another process owns this TPM\n");
rc = -EBUSY;
goto err_out;
put_device(chip->dev);
return -EBUSY;
}
get_device(chip->dev);
spin_unlock(&driver_lock);
chip->data_buffer = kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
if (chip->data_buffer == NULL) {
clear_bit(0, &chip->is_open);
@ -999,26 +994,23 @@ int tpm_open(struct inode *inode, struct file *file)
file->private_data = chip;
return 0;
err_out:
spin_unlock(&driver_lock);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_open);
/*
* Called on file close
*/
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;
del_singleshot_timer_sync(&chip->user_read_timer);
atomic_set(&chip->data_pending, 0);
kfree(chip->data_buffer);
clear_bit(0, &chip->is_open);
put_device(chip->dev);
kfree(chip->data_buffer);
spin_unlock(&driver_lock);
return 0;
}
EXPORT_SYMBOL_GPL(tpm_release);
@ -1092,13 +1084,11 @@ void tpm_remove_hardware(struct device *dev)
}
spin_lock(&driver_lock);
list_del(&chip->list);
list_del_rcu(&chip->list);
spin_unlock(&driver_lock);
synchronize_rcu();
misc_deregister(&chip->vendor.miscdev);
sysfs_remove_group(&dev->kobj, chip->vendor.attr_group);
tpm_bios_log_teardown(chip->bios_dir);
@ -1146,8 +1136,7 @@ EXPORT_SYMBOL_GPL(tpm_pm_resume);
/*
* Once all references to platform device are down to 0,
* release all allocated structures.
* In case vendor provided release function,
* call it too.
* In case vendor provided release function, call it too.
*/
static void tpm_dev_release(struct device *dev)
{
@ -1155,7 +1144,6 @@ static void tpm_dev_release(struct device *dev)
if (chip->vendor.release)
chip->vendor.release(dev);
chip->release(dev);
clear_bit(chip->dev_num, dev_mask);
@ -1170,8 +1158,8 @@ static void tpm_dev_release(struct device *dev)
* upon errant exit from this function specific probe function should call
* pci_disable_device
*/
struct tpm_chip *tpm_register_hardware(struct device *dev, const struct tpm_vendor_specific
*entry)
struct tpm_chip *tpm_register_hardware(struct device *dev,
const struct tpm_vendor_specific *entry)
{
#define DEVNAME_SIZE 7
@ -1230,21 +1218,20 @@ struct tpm_chip *tpm_register_hardware(struct device *dev, const struct tpm_vend
return NULL;
}
spin_lock(&driver_lock);
list_add(&chip->list, &tpm_chip_list);
spin_unlock(&driver_lock);
if (sysfs_create_group(&dev->kobj, chip->vendor.attr_group)) {
list_del(&chip->list);
misc_deregister(&chip->vendor.miscdev);
put_device(chip->dev);
return NULL;
}
chip->bios_dir = tpm_bios_log_setup(devname);
/* Make chip available */
spin_lock(&driver_lock);
list_add_rcu(&chip->list, &tpm_chip_list);
spin_unlock(&driver_lock);
return chip;
}
EXPORT_SYMBOL_GPL(tpm_register_hardware);