[3.13.y.z extended stable] Patch "xtensa: fix address checks in dma_{alloc, free}_coherent" has been added to staging queue

Kamal Mostafa kamal at canonical.com
Tue Sep 30 21:29:31 UTC 2014


This is a note to let you know that I have just added a patch titled

    xtensa: fix address checks in dma_{alloc,free}_coherent

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.8.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 3b2239f72c4df27cc37100fcd279bbff4d339add Mon Sep 17 00:00:00 2001
From: Alan Douglas <adouglas at cadence.com>
Date: Wed, 23 Jul 2014 14:06:40 +0400
Subject: xtensa: fix address checks in dma_{alloc,free}_coherent

commit 1ca49463c44c970b1ab1d71b0f268bfdf8427a7e upstream.

Virtual address is translated to the XCHAL_KSEG_CACHED region in the
dma_free_coherent, but is checked to be in the 0...XCHAL_KSEG_SIZE
range.

Change check for end of the range from 'addr >= X' to 'addr > X - 1' to
handle the case of X == 0.

Replace 'if (C) BUG();' construct with 'BUG_ON(C);'.

Signed-off-by: Alan Douglas <adouglas at cadence.com>
Signed-off-by: Max Filippov <jcmvbkbc at gmail.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/xtensa/kernel/pci-dma.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
index 2d9cc6d..e8b76b8 100644
--- a/arch/xtensa/kernel/pci-dma.c
+++ b/arch/xtensa/kernel/pci-dma.c
@@ -49,9 +49,8 @@ dma_alloc_coherent(struct device *dev,size_t size,dma_addr_t *handle,gfp_t flag)

 	/* We currently don't support coherent memory outside KSEG */

-	if (ret < XCHAL_KSEG_CACHED_VADDR
-	    || ret >= XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE)
-		BUG();
+	BUG_ON(ret < XCHAL_KSEG_CACHED_VADDR ||
+	       ret > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);


 	if (ret != 0) {
@@ -68,10 +67,11 @@ EXPORT_SYMBOL(dma_alloc_coherent);
 void dma_free_coherent(struct device *hwdev, size_t size,
 			 void *vaddr, dma_addr_t dma_handle)
 {
-	long addr=(long)vaddr+XCHAL_KSEG_CACHED_VADDR-XCHAL_KSEG_BYPASS_VADDR;
+	unsigned long addr = (unsigned long)vaddr +
+		XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;

-	if (addr < 0 || addr >= XCHAL_KSEG_SIZE)
-		BUG();
+	BUG_ON(addr < XCHAL_KSEG_CACHED_VADDR ||
+	       addr > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);

 	free_pages(addr, get_order(size));
 }
--
1.9.1





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