lkml.org 
[lkml]   [2010]   [Jul]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/2] memrar: Address kernel oops during resource cleanup
Date
From: Ossama Othman <ossama.othman@intel.com>

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 <ossama.othman@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
---

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;


\
 
 \ /
  Last update: 2010-07-19 11:05    [W:0.022 / U:0.344 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site