[PATCH 2/5] mm/highmem: Pass a pointer to virt_to_page()

Linus Walleij
2022-06-30T08:43:53Z

Functions that work on a pointer to virtual memory such as
virt_to_pfn() and users of that function such as
virt_to_page() are supposed to pass a pointer to virtual
memory, ideally a (void *) or other pointer. However since
many architectures implement virt_to_pfn() as a macro,
this function becomes polymorphic and accepts both a
(unsigned long) and a (void *).

If we instead implement a proper virt_to_pfn(void *addr)
function the following happens (occurred on arch/arm):

mm/highmem.c:153:29: warning: passing argument 1 of
'virt_to_pfn' makes pointer from integer without a
cast [-Wint-conversion]

We already have a proper void * pointer in the scope of this
function named "vaddr" so pass that instead.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
mm/highmem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/highmem.c b/mm/highmem.c
index 1a692997fac4..e92a7ceb30e8 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -150,7 +150,7 @@ struct page *__kmap_to_page(void *vaddr)
return pte_page(pkmap_page_table[i]);
}

- return virt_to_page(addr);
+ return virt_to_page(vaddr);
}
EXPORT_SYMBOL(__kmap_to_page);

--
2.36.1