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/gup.c: In function '__get_user_pages_locked': mm/gup.c:1599:49: warning: passing argument 1 of 'virt_to_pfn' makes pointer from integer without a cast [-Wint-conversion] pages[i] = virt_to_page(start); Fix this with an explicit cast. Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: linux-mm@xxxxxxxxx Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> --- mm/gup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/gup.c b/mm/gup.c index 551264407624..543c68da65f1 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1672,7 +1672,7 @@ static long __get_user_pages_locked(struct mm_struct *mm, unsigned long start, goto finish_or_fault; if (pages) { - pages[i] = virt_to_page(start); + pages[i] = virt_to_page((void *)start); if (pages[i]) get_page(pages[i]); } -- 2.36.1