From bdab18633a302c82b5e5d5dbc4e38b0baf9c0837 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 20 Sep 2026 08:15:23 -0700 Subject: Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull futex fix from Ingo Molnar: - Also allocate a default private futex hash on vfork() as well, to avoid races with (private) futex waiters (Peter Zijlstra) * tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Also allocate private hash on vfork() --- arch/x86/boot/bitops.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 arch/x86/boot/bitops.h (limited to 'arch/x86/boot/bitops.h') diff --git a/arch/x86/boot/bitops.h b/arch/x86/boot/bitops.h new file mode 100644 index 000000000..79e159715 --- /dev/null +++ b/arch/x86/boot/bitops.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * Very simple bitops for the boot code. + */ + +#ifndef BOOT_BITOPS_H +#define BOOT_BITOPS_H +#define _LINUX_BITOPS_H /* Inhibit inclusion of */ + +#include +#include + +static inline bool constant_test_bit(int nr, const void *addr) +{ + const u32 *p = addr; + return ((1UL << (nr & 31)) & (p[nr >> 5])) != 0; +} +static inline bool variable_test_bit(int nr, const void *addr) +{ + bool v; + const u32 *p = addr; + + asm("btl %2,%1" : "=@ccc" (v) : "m" (*p), "Ir" (nr)); + return v; +} + +#define test_bit(nr,addr) \ +(__builtin_constant_p(nr) ? \ + constant_test_bit((nr),(addr)) : \ + variable_test_bit((nr),(addr))) + +static inline void set_bit(int nr, void *addr) +{ + asm("btsl %1,%0" : "+m" (*(u32 *)addr) : "Ir" (nr)); +} + +#endif /* BOOT_BITOPS_H */ -- cgit v1.3.1