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Message-Id: <1384376168-2148-1-git-send-email-shuah.kh@samsung.com>
Date: Wed, 13 Nov 2013 13:56:08 -0700
From: Shuah Khan <shuah.kh@...sung.com>
To: akpm@...ux-foundation.org, alexander.h.duyck@...el.com,
joro@...tes.org
Cc: Shuah Khan <shuah.kh@...sung.com>, linux-kernel@...r.kernel.org,
shuahkhan@...il.com
Subject: [PATCH v2] dma-debug: enhance dma_debug_device_change() to check for mapping errors
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@...sung.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;
}
@@ -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
--
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