user/sven/linux.git/lib/dma-debug.c, branch v3.9.7

dma-debug: update DMA debug API to better handle multiple mappings of a buffer

2013-03-22T23:41:20Z

There were reports of the igb driver unmapping buffers without calling dma_mapping_error. On closer inspection issues were found in the DMA debug API and how it handled multiple mappings of the same buffer. The issue I found is the fact that the debug_dma_mapping_error would only set the map_err_type to MAP_ERR_CHECKED in the case that the was only one match for device and device address. However in the case of non-IOMMU, multiple addresses existed and as a result it was not setting this field once a second mapping was instantiated. I have resolved this by changing the search so that it instead will now set MAP_ERR_CHECKED on the first buffer that matches the device and DMA address that is currently in the state MAP_ERR_NOT_CHECKED. A secondary side effect of this patch is that in the case of multiple buffers using the same address only the last mapping will have a valid map_err_type. The previous mappings will all end up with map_err_type set to MAP_ERR_CHECKED because of the dma_mapping_error call in debug_dma_map_page. However this behavior may be preferable as it means you will likely only see one real error per multi-mapped buffer, versus the current behavior of multiple false errors mer multi-mapped buffer. Signed-off-by: Alexander Duyck Cc: Joerg Roedel Reviewed-by: Shuah Khan Tested-by: Shuah Khan Cc: Jakub Kicinski Cc: Konrad Rzeszutek Wilk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

dma-debug: fix locking bug in check_unmap()

2013-03-22T23:41:20Z

In check_unmap() it is possible to get into a dead-locked state if dma_mapping_error is called. The problem is that the bucket is locked in check_unmap, and locked again by debug_dma_mapping_error which is called by dma_mapping_error. To resolve that we must release the lock on the bucket before making the call to dma_mapping_error. [akpm@linux-foundation.org: restore 80-col trickery to be consistent with the rest of the file] Signed-off-by: Alexander Duyck Cc: Joerg Roedel Reviewed-by: Shuah Khan Tested-by: Shuah Khan Cc: Jakub Kicinski Cc: Konrad Rzeszutek Wilk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

dma-debug: fix to not have dependency on get_dma_ops() interface

2012-11-17T12:06:41Z

dma-debug depends on get_dma_ops() interface. Several architectures do not define dma_ops and get_dma_ops(). When dma debug interfaces are used on an architecture (e.g: c6x) that doesn't define get_dmap_ops(), compilation fails. Changing dma-debug to call dma_mapping_error() instead of defining its own that calls get_dma_ops(), such that the internal use of dma_mapping_error() doesn't interfere with the debug_dma_mapping_error() interface's mapping error checks. Moving dma_mapping_error() checks in check_unmap() under the dma debug entry not found is sufficient to fix the problem. Reference: https://lkml.org/lkml/2012/10/26/367 Signed-off-by: Shuah Khan Reported-by: Mark Salter Signed-off-by: Joerg Roedel

dma-debug: New interfaces to debug dma mapping errors

2012-10-24T15:06:43Z

Add dma-debug interface debug_dma_mapping_error() to debug drivers that fail to check dma mapping errors on addresses returned by dma_map_single() and dma_map_page() interfaces. This interface clears a flag set by debug_dma_map_page() to indicate that dma_mapping_error() has been called by the driver. When driver does unmap, debug_dma_unmap() checks the flag and if this flag is still set, prints warning message that includes call trace that leads up to the unmap. This interface can be called from dma_mapping_error() routines to enable dma mapping error check debugging. Tested: Intel iommu and swiotlb (iommu=soft) on x86-64 with CONFIG_DMA_API_DEBUG enabled and disabled. Signed-off-by: Shuah Khan Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Joerg Roedel

lib/dma-debug.c: fix __hash_bucket_find()

2012-10-19T21:07:48Z

If there is only one match, the unique matched entry should be returned. Without the fix, the upcoming dma debug interfaces ("dma-debug: new interfaces to debug dma mapping errors") can't work reliably because only device and dma_addr are passed to dma_mapping_error(). Signed-off-by: Ming Lei Reported-by: Wu Fengguang Cc: Joerg Roedel Tested-by: Shuah Khan Cc: Paul Gortmaker Cc: Jakub Kicinski Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

dma-debug: Remove local BUS_NOTIFY_UNBOUND_DRIVER define

2012-10-02T10:10:27Z

Remove local BUS_NOTIFY_UNBOUND_DRIVER define. This is not used since BUS_NOTIFY_UNBOUND_DRIVER is defined in include/linux/device.h Signed-off-by: Shuah Khan Signed-off-by: Joerg Roedel

dma-debug: debugfs_create_bool() takes a u32 pointer

2012-07-02T10:11:40Z

Even though it has "bool" in the name, you have pass a u32 pointer to debugfs_create_bool(). Otherwise you get memory corruption in write_file_bool(). Fortunately in this case the corruption happens in an alignment hole between variables so it doesn't cause any problems. Signed-off-by: Dan Carpenter Signed-off-by: Joerg Roedel

dma-debug: release free_entries_lock before saving stack trace

2012-04-12T10:28:46Z

Saving stack trace can take a while and once the entry is allocated free_entries_lock is no longer needed. Signed-off-by: Jakub Kicinski Signed-off-by: Joerg Roedel

Remove useless get_driver()/put_driver() calls

2012-01-25T00:00:35Z

As part of the removal of get_driver()/put_driver(), this patch (as1512) gets rid of various useless and unnecessary calls in several drivers. In some cases it may be desirable to pin the driver by calling try_module_get(), but that can be done later. Signed-off-by: Alan Stern CC: "David S. Miller" CC: Konrad Rzeszutek Wilk CC: Michael Buesch CC: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

Fix comparison using wrong pointer variable in dma debug code

2011-11-21T10:35:37Z

cppcheck reported: [lib/dma-debug.c:248] -> [lib/dma-debug.c:248]: (style) Same expression on both sides of '=='. Signed-off-by: Thomas Jarosch Signed-off-by: Joerg Roedel