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| author |   Shaun Ruffell <sruffell@digium.com> | 2009-12-17 18:00:36 -0600 |
|---|---|---|
| committer |   Joerg Roedel <joerg.roedel@amd.com> | 2009-12-21 15:10:12 +0100 |
| commit | f797d9881b62c2ddb1d2e7bd80d87141949c84aa (patch) | |
| tree | e52785a6c036130cfbe82b0ad9e5cc364acc7be4 /lib/radix-tree.c | |
| parent | Linux 2.6.33-rc1 (diff) | |
| download | linux-dev-f797d9881b62c2ddb1d2e7bd80d87141949c84aa.tar.xz linux-dev-f797d9881b62c2ddb1d2e7bd80d87141949c84aa.zip | |
dma-debug: Do not add notifier when dma debugging is disabled.
If CONFIG_HAVE_DMA_API_DEBUG is defined and "dma_debug=off" is
specified on the kernel command line, when you detach a driver from a
device you can cause the following NULL pointer dereference:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<c0580d35>] dma_debug_device_change+0x5d/0x117
The problem is that the dma_debug_device_change notifier function is
added to the bus notifier chain even though the dma_entry_hash array
was never initialized. If dma debugging is disabled, this patch both
prevents dma_debug_device_change notifiers from being added to the
chain, and additionally ensures that the dma_debug_device_change
notifier function is a no-op.
Cc: stable@kernel.org
Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Diffstat (limited to 'lib/radix-tree.c')
0 files changed, 0 insertions, 0 deletions