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[3.19.y-ckt,stable] Patch "dma-debug: Fix dma_debug_entry offset calculation" has been added to the 3.19.y-ckt tree

Message ID 1453251814-26063-1-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa Jan. 20, 2016, 1:03 a.m. UTC 
This is a note to let you know that I have just added a patch titled

    dma-debug: Fix dma_debug_entry offset calculation

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt13.

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

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

From 9108bc6de3c5c983f7214a4100ad1b0a9f5aaf11 Mon Sep 17 00:00:00 2001
From: Daniel Mentz <danielmentz@google.com>
Date: Tue, 15 Dec 2015 17:38:48 -0800
Subject: dma-debug: Fix dma_debug_entry offset calculation

commit 0354aec19ce3d355c6213b0434064efc25c9b22c upstream.

dma-debug uses struct dma_debug_entry to keep track of dma coherent
memory allocation requests. The virtual address is converted into a pfn
and an offset. Previously, the offset was calculated using an incorrect
bit mask.  As a result, we saw incorrect error messages from dma-debug
like the following:

"DMA-API: exceeded 7 overlapping mappings of cacheline 0x03e00000"

Cacheline 0x03e00000 does not exist on our platform.

Fixes: 0abdd7a81b7e ("dma-debug: introduce debug_dma_assert_idle()")
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 lib/dma-debug.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--
1.9.1
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Patch

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index d75c2f4..340776a 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -1456,7 +1456,7 @@  void debug_dma_alloc_coherent(struct device *dev, size_t size,
 	entry->type      = dma_debug_coherent;
 	entry->dev       = dev;
 	entry->pfn	 = page_to_pfn(virt_to_page(virt));
-	entry->offset	 = (size_t) virt & PAGE_MASK;
+	entry->offset	 = (size_t) virt & ~PAGE_MASK;
 	entry->size      = size;
 	entry->dev_addr  = dma_addr;
 	entry->direction = DMA_BIDIRECTIONAL;
@@ -1472,7 +1472,7 @@  void debug_dma_free_coherent(struct device *dev, size_t size,
 		.type           = dma_debug_coherent,
 		.dev            = dev,
 		.pfn		= page_to_pfn(virt_to_page(virt)),
-		.offset		= (size_t) virt & PAGE_MASK,
+		.offset		= (size_t) virt & ~PAGE_MASK,
 		.dev_addr       = addr,
 		.size           = size,
 		.direction      = DMA_BIDIRECTIONAL,