From: david.laight.linux@gmail.com
To: Nathan Chancellor <nathan@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Arnd Bergmann <arnd@arndb.de>,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
Yury Norov <yury.norov@gmail.com>,
Lucas De Marchi <lucas.demarchi@intel.com>,
Jani Nikula <jani.nikula@intel.com>,
Vincent Mailhol <mailhol.vincent@wanadoo.fr>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>
Cc: David Laight <david.laight.linux@gmail.com>
Subject: [PATCH next 12/14] bits: move the defitions of BIT() and BIT_ULL() back to linux/bits.h
Date: Wed, 21 Jan 2026 14:57:29 +0000 [thread overview]
Message-ID: <20260121145731.3623-13-david.laight.linux@gmail.com> (raw)
In-Reply-To: <20260121145731.3623-1-david.laight.linux@gmail.com>
From: David Laight <david.laight.linux@gmail.com>
The definition of BIT() was moved from linux/bits.h to vdso/bits.h to
isolate the vdso from 'normal' kernel headers.
BIT_ULL() was then moved to be defined in the same place for consistency.
Since then linux/bits.h had gained BIT_Unn() and it really makes sense
for BIT() and BIT_ULL() to be defined in the same place.
Move BIT_ULL() and make code that include both headers use the definition
of BIT() from linux/bits.h
Add BIT_U128() for completness.
This lets BIT() pick up the extra compile time checks for W=[1c] builds
that detect errors like:
long foo(void) { int x = 64; return BIT(x); }
For which clang (silently) just generates a 'return' instruction.
Note that nothing the the x86-64 build relies on the definition in
vdso/bits.h, linux/bits.h is always included.
Signed-off-by: David Laight <david.laight.linux@gmail.com>
---
include/linux/bits.h | 7 ++++++-
include/vdso/bits.h | 2 +-
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/include/linux/bits.h b/include/linux/bits.h
index 0f559038981d..3dd32b9eef35 100644
--- a/include/linux/bits.h
+++ b/include/linux/bits.h
@@ -2,7 +2,6 @@
#ifndef __LINUX_BITS_H
#define __LINUX_BITS_H
-#include <vdso/bits.h>
#include <uapi/linux/bits.h>
#define BIT_MASK(nr) (UL(1) << ((nr) % BITS_PER_LONG))
@@ -89,10 +88,16 @@ int BIT_INPUT_CHECK_FAIL(void) __compiletime_error("Bit number out of range");
((unsigned int)BIT_INPUT_CHECK(+(nr), BITS_PER_TYPE(type)) + ((type)1 << (nr)))
#endif /* defined(__ASSEMBLY__) */
+/* Prefer this definition of BIT() to the one in vdso/bits.h */
+#undef BIT
+#define __VDSO_BITS_H
+#define BIT(nr) BIT_TYPE(unsigned long, nr)
+#define BIT_ULL(nr) BIT_TYPE(unsigned long long, nr)
#define BIT_U8(nr) BIT_TYPE(u8, nr)
#define BIT_U16(nr) BIT_TYPE(u16, nr)
#define BIT_U32(nr) BIT_TYPE(u32, nr)
#define BIT_U64(nr) BIT_TYPE(u64, nr)
+#define BIT_U128(nr) BIT_TYPE(u128, nr)
#if defined(__ASSEMBLY__)
diff --git a/include/vdso/bits.h b/include/vdso/bits.h
index 388b212088ea..a6ac1e6b637c 100644
--- a/include/vdso/bits.h
+++ b/include/vdso/bits.h
@@ -4,7 +4,7 @@
#include <vdso/const.h>
+/* Most code picks up BIT() from linux/bits.h */
#define BIT(nr) (UL(1) << (nr))
-#define BIT_ULL(nr) (ULL(1) << (nr))
#endif /* __VDSO_BITS_H */
--
2.39.5
next prev parent reply other threads:[~2026-01-21 14:58 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-21 14:57 [PATCH next 00/14] bits: De-bloat expansion of GENMASK() david.laight.linux
2026-01-21 14:57 ` [PATCH next 01/14] overflow: Reduce expansion of __type_max() david.laight.linux
2026-01-21 20:59 ` Kees Cook
2026-02-02 16:45 ` Yury Norov
2026-01-21 14:57 ` [PATCH next 02/14] kbuild: Add W=c for additional compile time checks david.laight.linux
2026-02-02 18:33 ` Yury Norov
2026-02-02 20:07 ` David Laight
2026-02-03 4:47 ` Nathan Chancellor
2026-02-03 11:14 ` David Laight
2026-02-03 19:41 ` Yury Norov
2026-01-21 14:57 ` [PATCH next 03/14] media: videobuf2-core: Use static_assert() for sanity check david.laight.linux
2026-01-21 14:57 ` [PATCH next 04/14] media: atomisp: " david.laight.linux
2026-01-21 14:57 ` [PATCH next 05/14] ixgbevf: Use C test for PAGE_SIZE > IXGBE_MAX_DATA_PER_TXD david.laight.linux
2026-01-23 15:44 ` Simon Horman
2026-01-21 14:57 ` [PATCH next 06/14] asm-generic: include linux/bits.h not vdso/bits.h david.laight.linux
2026-01-21 14:57 ` [PATCH next 07/14] x86/tlb: " david.laight.linux
2026-01-21 14:57 ` [PATCH next 08/14] bits: simplify GENMASK_TYPE() david.laight.linux
2026-02-08 2:36 ` Yury Norov
2026-02-09 9:42 ` David Laight
2026-01-21 14:57 ` [PATCH next 09/14] bits: Change BIT_U8/16() and GENMASK_U8/16() to have unsigned values david.laight.linux
2026-01-21 14:57 ` [PATCH next 10/14] bits: Fix assmebler expansions of GENMASK_Uxx() and BIT_Uxx() david.laight.linux
2026-02-08 3:31 ` Yury Norov
2026-02-08 11:42 ` David Laight
2026-02-08 21:20 ` Yury Norov
2026-02-08 22:27 ` David Laight
2026-01-21 14:57 ` [PATCH next 11/14] bit: Strengthen compile-time tests in GENMASK() and BIT() david.laight.linux
2026-01-21 18:43 ` Vincent Mailhol
2026-01-21 19:14 ` David Laight
2026-01-22 1:11 ` kernel test robot
2026-01-22 10:25 ` David Laight
2026-01-22 20:10 ` David Laight
2026-01-22 4:41 ` kernel test robot
2026-01-22 10:33 ` David Laight
2026-01-22 14:26 ` Andy Shevchenko
2026-01-22 14:55 ` David Laight
2026-01-23 1:25 ` Philip Li
2026-01-23 8:01 ` Vincent Mailhol
2026-01-23 8:11 ` Andy Shevchenko
2026-01-23 8:20 ` Al Viro
2026-01-23 8:24 ` Andy Shevchenko
2026-01-23 8:32 ` Vincent Mailhol
2026-01-23 8:46 ` Andy Shevchenko
2026-01-23 1:24 ` Philip Li
2026-01-21 14:57 ` david.laight.linux [this message]
2026-01-21 15:17 ` [PATCH next 12/14] bits: move the defitions of BIT() and BIT_ULL() back to linux/bits.h Thomas Weißschuh
2026-01-21 19:24 ` David Laight
2026-01-22 7:39 ` Thomas Weißschuh
2026-01-22 0:50 ` kernel test robot
2026-01-22 1:23 ` kernel test robot
2026-01-22 10:30 ` David Laight
2026-02-07 22:40 ` Thomas Gleixner
2026-02-08 4:23 ` Yury Norov
2026-01-21 14:57 ` [PATCH next 13/14] test_bits: Change all the tests to be compile-time tests david.laight.linux
2026-02-08 4:37 ` Yury Norov
2026-02-08 11:32 ` David Laight
2026-01-21 14:57 ` [PATCH next 14/14] test_bits: include some invalid input tests for GENMASK_INPUT_CHECK() david.laight.linux
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260121145731.3623-13-david.laight.linux@gmail.com \
--to=david.laight.linux@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=andriy.shevchenko@linux.intel.com \
--cc=arnd@arndb.de \
--cc=gregkh@linuxfoundation.org \
--cc=jani.nikula@intel.com \
--cc=keescook@chromium.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lucas.demarchi@intel.com \
--cc=mailhol.vincent@wanadoo.fr \
--cc=mathieu.desnoyers@efficios.com \
--cc=mingo@kernel.org \
--cc=nathan@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=yury.norov@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox