From: Arnd Bergmann <arnd@arndb.de>
Date: Mon, 27 Sep 2021 12:13:57 +0000 (+0200)
Subject: cb710: avoid NULL pointer subtraction
X-Git-Tag: v5.15~70^2~10
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=42641042c10c757fe10cc09088cf3f436cec5007;p=platform%2Fkernel%2Flinux-starfive.git

cb710: avoid NULL pointer subtraction

clang-14 complains about an unusual way of converting a pointer to
an integer:

drivers/misc/cb710/sgbuf2.c:50:15: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction]
        return ((ptr - NULL) & 3) != 0;

Replace this with a normal cast to uintptr_t.

Fixes: 5f5bac8272be ("mmc: Driver for CB710/720 memory card reader (MMC part)")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210927121408.939246-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/misc/cb710/sgbuf2.c b/drivers/misc/cb710/sgbuf2.c
index e5a4ed3..a798fad 100644
--- a/drivers/misc/cb710/sgbuf2.c
+++ b/drivers/misc/cb710/sgbuf2.c
@@ -47,7 +47,7 @@ static inline bool needs_unaligned_copy(const void *ptr)
 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
 	return false;
 #else
-	return ((ptr - NULL) & 3) != 0;
+	return ((uintptr_t)ptr & 3) != 0;
 #endif
 }