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Subject[PATCH 08/10] staging: gasket: cleanup if dma_map_page fails in gasket_perform_mapping
Date
From: Nick Ewalt <nicholasewalt@google.com>

Previously pages would have never been unmapped in this case.

Signed-off-by: Nick Ewalt <nicholasewalt@google.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
---
drivers/staging/gasket/gasket_page_table.c | 33 +++++++++++++---------
1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/drivers/staging/gasket/gasket_page_table.c b/drivers/staging/gasket/gasket_page_table.c
index c1ce8f984f8e0..779ad2f23ef9b 100644
--- a/drivers/staging/gasket/gasket_page_table.c
+++ b/drivers/staging/gasket/gasket_page_table.c
@@ -433,6 +433,19 @@ static int is_coherent(struct gasket_page_table *pg_tbl, ulong host_addr)
return min <= host_addr && host_addr < max;
}

+/* Safely return a page to the OS. */
+static bool gasket_release_page(struct page *page)
+{
+ if (!page)
+ return false;
+
+ if (!PageReserved(page))
+ SetPageDirty(page);
+ put_page(page);
+
+ return true;
+}
+
/*
* Get and map last level page table buffers.
*
@@ -500,6 +513,13 @@ static int gasket_perform_mapping(struct gasket_page_table *pg_tbl,
(unsigned long long)ptes[i].dma_addr,
(void *)page_to_pfn(page),
(void *)page_to_phys(page));
+
+ /* clean up */
+ if (gasket_release_page(ptes[i].page))
+ --pg_tbl->num_active_pages;
+
+ memset(&ptes[i], 0,
+ sizeof(struct gasket_page_table_entry));
return -1;
}
}
@@ -571,19 +591,6 @@ static int gasket_alloc_simple_entries(struct gasket_page_table *pg_tbl,
return 0;
}

-/* Safely return a page to the OS. */
-static bool gasket_release_page(struct page *page)
-{
- if (!page)
- return false;
-
- if (!PageReserved(page))
- SetPageDirty(page);
- put_page(page);
-
- return true;
-}
-
/*
* Unmap and release mapped pages.
* The page table mutex must be held by the caller.
--
2.19.0.397.gdd90340f6a-goog
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