tpm: Provide strong locking for device removal

[cascardo/linux.git] / drivers / char / tpm / tpm-sysfs.c

diff --git a/drivers/char/tpm/tpm-sysfs.c b/drivers/char/tpm/tpm-sysfs.c
index d93736a..34e7fc7 100644 (file)
--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -295,5 +295,10 @@ int tpm_sysfs_add_device(struct tpm_chip *chip)
 
 void tpm_sysfs_del_device(struct tpm_chip *chip)
 {
+       /* The sysfs routines rely on an implicit tpm_try_get_ops, this
+        * function is called before ops is null'd and the sysfs core
+        * synchronizes this removal so that no callbacks are running or can
+        * run again
+        */
        sysfs_remove_group(&chip->dev.parent->kobj, &tpm_dev_group);
 }