linux-kernel - [PATCH 2/3] bits: unify the non-asm GENMASK*()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250322-consolidate-genmask-v1-2-54bfd36c5643@wanadoo.fr>
Date: Sat, 22 Mar 2025 19:39:37 +0900
From: Vincent Mailhol via B4 Relay <devnull+mailhol.vincent.wanadoo.fr@...nel.org>
To: Yury Norov <yury.norov@...il.com>, 
 Lucas De Marchi <lucas.demarchi@...el.com>, 
 Rasmus Villemoes <linux@...musvillemoes.dk>, 
 Jani Nikula <jani.nikula@...ux.intel.com>, 
 Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>, 
 Rodrigo Vivi <rodrigo.vivi@...el.com>, 
 Tvrtko Ursulin <tursulin@...ulin.net>, David Airlie <airlied@...il.com>, 
 Simona Vetter <simona@...ll.ch>, Andrew Morton <akpm@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, intel-gfx@...ts.freedesktop.org, 
 dri-devel@...ts.freedesktop.org, Andi Shyti <andi.shyti@...ux.intel.com>, 
 David Laight <David.Laight@...LAB.COM>, 
 Andy Shevchenko <andriy.shevchenko@...ux.intel.com>, 
 Vincent Mailhol <mailhol.vincent@...adoo.fr>
Subject: [PATCH 2/3] bits: unify the non-asm GENMASK*()

From: Vincent Mailhol <mailhol.vincent@...adoo.fr>

The newly introduced GENMASK_TYPE() macro can also be used to generate
the pre-existing non-asm GENMASK*() variants.

Apply GENMASK_TYPE() to GENMASK(), GENMASK_ULL() and GENMASK_U128().

Signed-off-by: Vincent Mailhol <mailhol.vincent@...adoo.fr>
---
 include/linux/bits.h | 26 ++++----------------------
 1 file changed, 4 insertions(+), 22 deletions(-)

diff --git a/include/linux/bits.h b/include/linux/bits.h
index 9dd2d244c1f37fde995ed65c1eed879bb2a994a8..025c9cb994b148f8d2e50e69be929d356c6c4322 100644
--- a/include/linux/bits.h
+++ b/include/linux/bits.h
@@ -2,10 +2,8 @@
 #ifndef __LINUX_BITS_H
 #define __LINUX_BITS_H
 
-#include <linux/const.h>
 #include <vdso/bits.h>
 #include <uapi/linux/bits.h>
-#include <asm/bitsperlong.h>
 
 #define BIT_MASK(nr)		(UL(1) << ((nr) % BITS_PER_LONG))
 #define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
@@ -35,11 +33,6 @@
 
 #define GENMASK_INPUT_CHECK(h, l) BUILD_BUG_ON_ZERO(const_true((l) > (h)))
 
-#define GENMASK(h, l) \
-	(GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
-#define GENMASK_ULL(h, l) \
-	(GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
-
 /*
  * Generate a mask for the specified type @t. Additional checks are made to
  * guarantee the value returned fits in that type, relying on
@@ -55,10 +48,14 @@
 	     (type_max(t) << (l) &				\
 	      type_max(t) >> (BITS_PER_TYPE(t) - 1 - (h)))))
 
+#define GENMASK(h, l)		GENMASK_TYPE(unsigned long, h, l)
+#define GENMASK_ULL(h, l)	GENMASK_TYPE(unsigned long long, h, l)
+
 #define GENMASK_U8(h, l)	GENMASK_TYPE(u8, h, l)
 #define GENMASK_U16(h, l)	GENMASK_TYPE(u16, h, l)
 #define GENMASK_U32(h, l)	GENMASK_TYPE(u32, h, l)
 #define GENMASK_U64(h, l)	GENMASK_TYPE(u64, h, l)
+#define GENMASK_U128(h, l)	GENMASK_TYPE(u128, h, l)
 
 /*
  * Fixed-type variants of BIT(), with additional checks like GENMASK_TYPE(). The
@@ -89,19 +86,4 @@
 
 #endif /* !defined(__ASSEMBLY__) */
 
-#if !defined(__ASSEMBLY__)
-/*
- * Missing asm support
- *
- * __GENMASK_U128() depends on _BIT128() which would not work
- * in the asm code, as it shifts an 'unsigned __int128' data
- * type instead of direct representation of 128 bit constants
- * such as long and unsigned long. The fundamental problem is
- * that a 128 bit constant will get silently truncated by the
- * gcc compiler.
- */
-#define GENMASK_U128(h, l) \
-	(GENMASK_INPUT_CHECK(h, l) + __GENMASK_U128(h, l))
-#endif
-
 #endif	/* __LINUX_BITS_H */

-- 
2.48.1