[PATCH] uapi/linux/const.h: Prefer ISO-friendly __typeof__

From: Kevin Brodsky
Date: Thu Jan 19 2023 - 04:42:47 EST


typeof is (still) a GNU extension, which means that it cannot be
used when building ISO C (e.g. -std=c99). It should therefore be
avoided in uapi headers in favour of the ISO-friendly __typeof__.

Unfortunately this issue could not be detected by
CONFIG_UAPI_HEADER_TEST=y as the __ALIGN_KERNEL() macro is not
expanded in any uapi header.

Reported-by: Ruben Ayrapetyan <ruben.ayrapetyan@xxxxxxx>
Tested-by: Ruben Ayrapetyan <ruben.ayrapetyan@xxxxxxx>
Signed-off-by: Kevin Brodsky <kevin.brodsky@xxxxxxx>
---
include/uapi/linux/const.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/uapi/linux/const.h b/include/uapi/linux/const.h
index af2a44c08683..a429381e7ca5 100644
--- a/include/uapi/linux/const.h
+++ b/include/uapi/linux/const.h
@@ -28,7 +28,7 @@
#define _BITUL(x) (_UL(1) << (x))
#define _BITULL(x) (_ULL(1) << (x))

-#define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
+#define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (__typeof__(x))(a) - 1)
#define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask))

#define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
--
2.38.1