diff options
| author |   Sudip Mukherjee <sudipm.mukherjee@gmail.com> | 2016-02-27 17:33:35 +0530 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-03-11 22:09:09 -0800 |
| commit | 18f038e6bfb715310526ac05e4f20e55683471de (patch) | |
| tree | 6334d23c572551408e07740a51e61d95f13e56a8 /drivers/staging/dgnc | |
| parent | staging: dgnc: unregister pci driver (diff) | |
| download | linux-dev-18f038e6bfb715310526ac05e4f20e55683471de.tar.xz linux-dev-18f038e6bfb715310526ac05e4f20e55683471de.zip | |
staging: dgnc: cleanup properly
dgnc_cleanup_module() was called when the module unloaded to do a total
cleanup and it was also called if pci_register_driver() fails. But
dgnc_cleanup_module() will try dgnc_remove_driver_sysfiles() but the
sysfiles will be created only if pci_register_driver() succeeds.
So if pci_register_driver() fails and we try dgnc_cleanup_module() then we
were getting:
[ 942.001479] BUG: unable to handle kernel NULL pointer dereference at 00000018
[ 942.001482] IP: [<c122c7a8>] sysfs_remove_file_ns+0x8/0x20
with part of the call trace as:
[ 942.001544] Call Trace:
[ 942.001555] [<c149acc6>] driver_remove_file+0x16/0x20
[ 942.001571] [<f864a708>] dgnc_remove_driver_sysfiles+0x18/0x40 [dgnc]
[ 942.001575] [<f8643ac7>] dgnc_cleanup_module+0x47/0x260 [dgnc]
[ 942.001577] [<f86cb000>] ? 0xf86cb000
[ 942.001580] [<f86cb1e6>] dgnc_init_module+0x1e6/0x1000 [dgnc]
Lets have a separate cleanup function which will execute
dgnc_remove_driver_sysfiles() depending on the argument passed to it.
Reported-by: Navy Cheng <navych@126.com>
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/dgnc')
| -rw-r--r-- | drivers/staging/dgnc/dgnc_driver.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/drivers/staging/dgnc/dgnc_driver.c b/drivers/staging/dgnc/dgnc_driver.c index 22a92d15ee9d..4eb410e09609 100644 --- a/drivers/staging/dgnc/dgnc_driver.c +++ b/drivers/staging/dgnc/dgnc_driver.c @@ -125,12 +125,7 @@ static struct pci_driver dgnc_driver = { * ************************************************************************/ -/* - * dgnc_cleanup_module() - * - * Module unload. This is where it all ends. - */ -static void dgnc_cleanup_module(void) +static void cleanup(bool sysfiles) { int i; unsigned long flags; @@ -142,7 +137,8 @@ static void dgnc_cleanup_module(void) /* Turn off poller right away. */ del_timer_sync(&dgnc_poll_timer); - dgnc_remove_driver_sysfiles(&dgnc_driver); + if (sysfiles) + dgnc_remove_driver_sysfiles(&dgnc_driver); device_destroy(dgnc_class, MKDEV(dgnc_Major, 0)); class_destroy(dgnc_class); @@ -155,7 +151,16 @@ static void dgnc_cleanup_module(void) } dgnc_tty_post_uninit(); +} +/* + * dgnc_cleanup_module() + * + * Module unload. This is where it all ends. + */ +static void dgnc_cleanup_module(void) +{ + cleanup(true); pci_unregister_driver(&dgnc_driver); } @@ -182,7 +187,7 @@ static int __init dgnc_init_module(void) rc = pci_register_driver(&dgnc_driver); if (rc) { pr_warn("WARNING: dgnc driver load failed. No Digi Neo or Classic boards found.\n"); - dgnc_cleanup_module(); + cleanup(false); return rc; } dgnc_create_driver_sysfiles(&dgnc_driver); |