mm/highmem: pass a pointer to virt_to_page()

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.

Link: https://lkml.kernel.org/r/20220630084124.691207-3-linus.walleij@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/highmem.c b/mm/highmem.c
index 1a692997fac4c9c913279a10d2077d20ddcb0751..e92a7ceb30e8d9530529061b955dece1529a77be 100644 (file)
--- 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);