dma-debug checks to verify if driver validated the address returned by dma mapping routines when driver does unmap. If a driver doesn't call unmap, failure to check mapping errors isn't detected and reported.
Enhancing existing bus notifier_call dma_debug_device_change() to check for mapping errors at the same time it detects leaked dma buffers for BUS_NOTIFY_UNBOUND_DRIVER event. It scans for mapping errors and if any found, prints one warning message that includes mapping error count. Signed-off-by: Shuah Khan <[email protected]> --- lib/dma-debug.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/lib/dma-debug.c b/lib/dma-debug.c index d87a17a..e34865e 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -717,6 +717,7 @@ static int device_dma_allocations(struct device *dev, struct dma_debug_entry **o struct dma_debug_entry *entry; unsigned long flags; int count = 0, i; + int map_err_cnt = 0; local_irq_save(flags); @@ -724,6 +725,8 @@ static int device_dma_allocations(struct device *dev, struct dma_debug_entry **o spin_lock(&dma_entry_hash[i].lock); list_for_each_entry(entry, &dma_entry_hash[i].list, list) { if (entry->dev == dev) { + if (entry->map_err_type == MAP_ERR_NOT_CHECKED) + map_err_cnt += 1; count += 1; *out_entry = entry; } @@ -733,6 +736,10 @@ static int device_dma_allocations(struct device *dev, struct dma_debug_entry **o local_irq_restore(flags); + if (map_err_cnt) + dev_warn(entry->dev, + "DMA-API: device driver failed to check map errors: " + "[count] = %d\n", map_err_cnt); return count; } -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
