From: Alexey Khoroshilov <khoroshilov@ispras.ru>
Date: Fri, 13 Jan 2017 22:52:51 +0000 (+0300)
Subject: mmc: wbsd: safer check if dma_addr is valid DMA address
X-Git-Tag: v4.11-rc1~140^2~77
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=e81c022a00cd91b0d555d9d9194d421e3b8d642c;p=uclinux-h8%2Flinux.git

mmc: wbsd: safer check if dma_addr is valid DMA address

host->dma_addr can store a value that is not returned by the DMA API,
so it is safer to check if is a valid DMA address indirectly.

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---

diff --git a/drivers/mmc/host/wbsd.c b/drivers/mmc/host/wbsd.c
index 80a3b11f3217..bd04e8bae010 100644
--- a/drivers/mmc/host/wbsd.c
+++ b/drivers/mmc/host/wbsd.c
@@ -1437,11 +1437,14 @@ err:
 
 static void wbsd_release_dma(struct wbsd_host *host)
 {
-	if (!dma_mapping_error(mmc_dev(host->mmc), host->dma_addr)) {
+	/*
+	 * host->dma_addr is valid here iff host->dma_buffer is not NULL.
+	 */
+	if (host->dma_buffer) {
 		dma_unmap_single(mmc_dev(host->mmc), host->dma_addr,
 			WBSD_DMA_SIZE, DMA_BIDIRECTIONAL);
+		kfree(host->dma_buffer);
 	}
-	kfree(host->dma_buffer);
 	if (host->dma >= 0)
 		free_dma(host->dma);