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From 795b9fab91c9b8e4fbd72395e4d7eaf70c394a12 Mon Sep 17 00:00:00 2001
From: Guangming <Guangming.Cao@mediatek.com>
Date: Fri, 26 Nov 2021 15:49:04 +0800
Subject: dma-buf: system_heap: Use 'for_each_sgtable_sg' in pages free flow
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Git-commit: 679d94cd7d900871e5bc9cf780bd5b73af35ab42
Patch-mainline: v5.16-rc4
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

For previous version, it uses 'sg_table.nent's to traverse sg_table in pages
free flow.
However, 'sg_table.nents' is reassigned in 'dma_map_sg', it means the number of
created entries in the DMA adderess space.
So, use 'sg_table.nents' in pages free flow will case some pages can't be freed.

Here we should use sg_table.orig_nents to free pages memory, but use the
sgtable helper 'for each_sgtable_sg'(, instead of the previous rather common
helper 'for_each_sg' which maybe cause memory leak) is much better.

Fixes: d963ab0f15fb0 ("dma-buf: system_heap: Allocate higher order pages if available")
Signed-off-by: Guangming <Guangming.Cao@mediatek.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Cc: <stable@vger.kernel.org> # 5.11.*
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211126074904.88388-1-guangming.cao@mediatek.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/dma-buf/heaps/system_heap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
index f57a39ddd063..ab7fd896d2c4 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -290,7 +290,7 @@ static void system_heap_dma_buf_release(struct dma_buf *dmabuf)
 	int i;
 
 	table = &buffer->sg_table;
-	for_each_sg(table->sgl, sg, table->nents, i) {
+	for_each_sgtable_sg(table, sg, i) {
 		struct page *page = sg_page(sg);
 
 		__free_pages(page, compound_order(page));
-- 
2.38.1