2010-07-19 09:03:49

by Alan

[permalink] [raw]
Subject: [PATCH 1/2] memrar: Address kernel oops during resource cleanup

From: Ossama Othman <[email protected]>

Some delayed initialization is performed in this driver. Make sure
resources that are used during driver clean-up (e.g. during driver's
release() function) are fully initialized before first use. This is
particularly important for the case when the delayed initialization
isn't completed, leaving behind a partially initialized driver.

Such a scenario can occur when RAR is not available on the platform,
and the driver is release()d.

Signed-off-by: Ossama Othman <[email protected]>
Signed-off-by: Alan Cox <[email protected]>
---

drivers/staging/memrar/memrar_handler.c | 28 +++++++++++++++++++---------
1 files changed, 19 insertions(+), 9 deletions(-)


diff --git a/drivers/staging/memrar/memrar_handler.c b/drivers/staging/memrar/memrar_handler.c
index 5fe6028..a98b3f1 100644
--- a/drivers/staging/memrar/memrar_handler.c
+++ b/drivers/staging/memrar/memrar_handler.c
@@ -278,15 +278,6 @@ static int memrar_init_rar_resources(int rarnum, char const *devname)
BUG_ON(!memrar_is_valid_rar_type(rarnum));
BUG_ON(rar->allocated);

- mutex_init(&rar->lock);
-
- /*
- * Initialize the process table before we reach any
- * code that exit on failure since the finalization
- * code requires an initialized list.
- */
- INIT_LIST_HEAD(&rar->buffers.list);
-
if (rar_get_address(rarnum, &low, &high) != 0)
/* No RAR is available. */
return -ENODEV;
@@ -940,9 +931,28 @@ static int memrar_registration_callback(unsigned long rar)
static int __init memrar_init(void)
{
int err;
+ int i;

printk(banner);

+ /*
+ * Some delayed initialization is performed in this driver.
+ * Make sure resources that are used during driver clean-up
+ * (e.g. during driver's release() function) are fully
+ * initialized before first use. This is particularly
+ * important for the case when the delayed initialization
+ * isn't completed, leaving behind a partially initialized
+ * driver.
+ *
+ * Such a scenario can occur when RAR is not available on the
+ * platform, and the driver is release()d.
+ */
+ for (i = 0; i != ARRAY_SIZE(memrars); ++i) {
+ struct memrar_rar_info * const rar = &memrars[i];
+ mutex_init(&rar->lock);
+ INIT_LIST_HEAD(&rar->buffers.list);
+ }
+
err = misc_register(&memrar_miscdev);
if (err)
return err;


2010-07-19 09:04:02

by Alan

[permalink] [raw]
Subject: [PATCH 2/2] memrar: Updated maintainer contact information

From: Ossama Othman <[email protected]>

Signed-off-by: Ossama Othman <[email protected]>
Signed-off-by: Alan Cox <[email protected]>
---

drivers/staging/memrar/TODO | 2 +-
drivers/staging/memrar/memrar-abi | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)


diff --git a/drivers/staging/memrar/TODO b/drivers/staging/memrar/TODO
index 0087447..435e09b 100644
--- a/drivers/staging/memrar/TODO
+++ b/drivers/staging/memrar/TODO
@@ -1,7 +1,7 @@
RAR Handler (memrar) Driver TODO Items
======================================

-Maintainer: Ossama Othman <[email protected]>
+Maintainer: Eugene Epshteyn <[email protected]>

memrar.h
--------
diff --git a/drivers/staging/memrar/memrar-abi b/drivers/staging/memrar/memrar-abi
index 98a6bb1..c23fc99 100644
--- a/drivers/staging/memrar/memrar-abi
+++ b/drivers/staging/memrar/memrar-abi
@@ -1,7 +1,7 @@
What: /dev/memrar
Date: March 2010
-KernelVersion: Kernel version this feature first showed up in.
-Contact: Ossama Othman <[email protected]>
+KernelVersion: 2.6.34
+Contact: Eugene Epshteyn <[email protected]>
Description: The Intel Moorestown Restricted Access Region (RAR)
Handler driver exposes an ioctl() based interface that
allows a user to reserve and release blocks of RAR