Messages in this thread | | | Date | Fri, 03 Jan 2014 11:26:04 -0700 | From | Shuah Khan <> | Subject | Re: [PATCH v2] dma-debug: enhance dma_debug_device_change() to check for mapping errors |
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On 12/30/2013 07:15 AM, Joerg Roedel wrote: > On Wed, Nov 13, 2013 at 01:56:08PM -0700, Shuah Khan wrote: >> 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 <shuah.kh@samsung.com> >> --- >> 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; > > I think it is better to check for this in a seperate function and use > err_printk instead of dev_warn in the end to print the errors. > The new function can then be called in the dma_debug_device_change > callback like device_dma_allocations is. >
I did explore separate function option and backed off from it since the new routine will have to duplicate what device_dma_allocations() does except that it checks for entry->map_err_type.
I still have the patch that does that saved away. If you still prefer that approach, I can rework the patch and send it.
-- Shuah
-- Shuah Khan Senior Linux Kernel Developer - Open Source Group Samsung Research America(Silicon Valley) shuah.kh@samsung.com | (970) 672-0658
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