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Subject[PATCH] tpm: fix cause of SMP stack traces
Date
From
ChangeSet 1.2036, 2005/03/09 10:12:38-08:00, kjhall@us.ibm.com

[PATCH] tpm: fix cause of SMP stack traces

There were misplaced spinlock acquires and releases in the probe, close and release
paths which were causing might_sleep and schedule while atomic error messages accompanied
by stack traces when the kernel was compiled with SMP support. Bug reported by Reben Jenster
<ruben@hotheads.de>

Signed-off-by: Kylene Hall <kjhall@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>


drivers/char/tpm/tpm.c | 16 ++++++++--------
1 files changed, 8 insertions(+), 8 deletions(-)

diff -Nru a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
--- a/drivers/char/tpm/tpm.c 2005-03-09 16:40:19 -08:00
+++ b/drivers/char/tpm/tpm.c 2005-03-09 16:40:19 -08:00
@@ -422,21 +422,24 @@
int tpm_release(struct inode *inode, struct file *file)
{
struct tpm_chip *chip = file->private_data;
+
+ file->private_data = NULL;

spin_lock(&driver_lock);
chip->num_opens--;
+ spin_unlock(&driver_lock);
+
down(&chip->timer_manipulation_mutex);
if (timer_pending(&chip->user_read_timer))
del_singleshot_timer_sync(&chip->user_read_timer);
else if (timer_pending(&chip->device_timer))
del_singleshot_timer_sync(&chip->device_timer);
up(&chip->timer_manipulation_mutex);
+
kfree(chip->data_buffer);
atomic_set(&chip->data_pending, 0);

pci_dev_put(chip->pci_dev);
- file->private_data = NULL;
- spin_unlock(&driver_lock);
return 0;
}

@@ -534,6 +537,8 @@

list_del(&chip->list);

+ spin_unlock(&driver_lock);
+
pci_set_drvdata(pci_dev, NULL);
misc_deregister(&chip->vendor->miscdev);

@@ -541,8 +546,6 @@
device_remove_file(&pci_dev->dev, &dev_attr_pcrs);
device_remove_file(&pci_dev->dev, &dev_attr_caps);

- spin_unlock(&driver_lock);
-
pci_disable_device(pci_dev);

dev_mask[chip->dev_num / 32] &= !(1 << (chip->dev_num % 32));
@@ -583,6 +586,7 @@
int tpm_pm_resume(struct pci_dev *pci_dev)
{
struct tpm_chip *chip = pci_get_drvdata(pci_dev);
+
if (chip == NULL)
return -ENODEV;

@@ -650,15 +654,12 @@
chip->vendor->miscdev.dev = &(pci_dev->dev);
chip->pci_dev = pci_dev_get(pci_dev);

- spin_lock(&driver_lock);
-
if (misc_register(&chip->vendor->miscdev)) {
dev_err(&chip->pci_dev->dev,
"unable to misc_register %s, minor %d\n",
chip->vendor->miscdev.name,
chip->vendor->miscdev.minor);
pci_dev_put(pci_dev);
- spin_unlock(&driver_lock);
kfree(chip);
dev_mask[i] &= !(1 << j);
return -ENODEV;
@@ -672,7 +673,6 @@
device_create_file(&pci_dev->dev, &dev_attr_pcrs);
device_create_file(&pci_dev->dev, &dev_attr_caps);

- spin_unlock(&driver_lock);
return 0;
}

-
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