From: Glauber Costa <gcosta@redhat.com>
Date: Wed, 9 Apr 2008 16:18:09 +0000 (-0300)
Subject: x86: don't do dma if mask is NULL.
X-Git-Tag: v2.6.26-rc1~1133^2~2
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bb8ada95a7c11adf3dad4e8d5c55ef1650560592;p=linux-2.6

x86: don't do dma if mask is NULL.

if the device hasn't provided a mask, abort allocation.
Note that we're using a fallback device now, so it does not cover
the case of a NULL device: just drivers passing NULL masks around.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---

diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c
index f134de3833..d2f70744a9 100644
--- a/arch/x86/kernel/pci-dma_32.c
+++ b/arch/x86/kernel/pci-dma_32.c
@@ -91,6 +91,9 @@ void *dma_alloc_coherent(struct device *dev, size_t size,
 	if (dma_mask == 0)
 		dma_mask = DMA_32BIT_MASK;
 
+	if (dev->dma_mask == NULL)
+		return NULL;
+
 	/* Don't invoke OOM killer */
 	gfp |= __GFP_NORETRY;
 again: