Patch "x86/pci-calgary: Fix iommu_free() comparison of unsigned expression >= 0" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

x86/pci-calgary: Fix iommu_free() comparison of unsigned expression >= 0

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
x86-pci-calgary-fix-iommu_free-comparison-of-unsigned-expression-0.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Nikola Pajkovsky <[email protected]>
Date: Tue, 15 Nov 2016 09:47:49 +0100
Subject: x86/pci-calgary: Fix iommu_free() comparison of unsigned expression >= 0
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From: Nikola Pajkovsky <[email protected]>

commit 68dee8e2f2cacc54d038394e70d22411dee89da2 upstream.

commit 8fd524b355da ("x86: Kill bad_dma_address variable") has killed bad_dma_address variable and used instead of macro DMA_ERROR_CODE which is always zero. Since dma_addr is unsigned, the statement

dma_addr >= DMA_ERROR_CODE

is always true, and not needed.

arch/x86/kernel/pci-calgary_64.c: In function ‘iommu_free’:
arch/x86/kernel/pci-calgary_64.c:299:2: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
if (unlikely((dma_addr >= DMA_ERROR_CODE) && (dma_addr < badend))) {

---
 arch/x86/kernel/pci-calgary_64.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -296,7 +296,7 @@ static void iommu_free(struct iommu_tabl
 
 	/* were we called with bad_dma_address? */
 	badend = DMA_ERROR_CODE + (EMERGENCY_PAGES * PAGE_SIZE);
-	if (unlikely((dma_addr >= DMA_ERROR_CODE) && (dma_addr < badend))) {
+	if (unlikely(dma_addr < badend)) {
 		WARN(1, KERN_ERR "Calgary: driver tried unmapping bad DMA "
 		       "address 0x%Lx\n", dma_addr);
 		return;

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/x86-pci-calgary-fix-iommu_free-comparison-of-unsigned-expression-0.patch