[PATCH] lib/dma-debug.c: fix memory leakage

[miles.chen at mediatek.com]

From: Miles Chen <miles.chen at mediatek.com>

Marty reported a memory leakage introduced by commit 3aaabbf1c39e
("lib/dma-debug.c: fix incorrect pfn calculation"). Fix it
by checking the virtual address before allocating the entry.

This patch also use virt_addr_valid() instead of virt_to_page()
to check if a virtual address is linear.

Reported-by: Marty Faltesek <mfaltesek at google.com>
Signed-off-by: Miles Chen <miles.chen at mediatek.com>
---
 lib/dma-debug.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 1b34d210452c..7f5cdc1e6b29 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -1491,12 +1491,12 @@ void debug_dma_alloc_coherent(struct device *dev, size_t size,
 	if (unlikely(virt == NULL))
 		return;
 
-	entry = dma_entry_alloc();
-	if (!entry)
+	/* handle vmalloc and linear addresses */
+	if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt))
 		return;
 
-	/* handle vmalloc and linear addresses */
-	if (!is_vmalloc_addr(virt) && !virt_to_page(virt))
+	entry = dma_entry_alloc();
+	if (!entry)
 		return;
 
 	entry->type      = dma_debug_coherent;
@@ -1528,7 +1528,7 @@ void debug_dma_free_coherent(struct device *dev, size_t size,
 	};
 
 	/* handle vmalloc and linear addresses */
-	if (!is_vmalloc_addr(virt) && !virt_to_page(virt))
+	if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt))
 		return;
 
 	if (is_vmalloc_addr(virt))
-- 
2.12.5