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platform_kernel-5.15
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platform_kernel-5.15/include/uapi/linux/stddef.h

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linux/compiler.h: Split into compiler.h and compiler_types.h linux/compiler.h is included indirectly by linux/types.h via uapi/linux/types.h -> uapi/linux/posix_types.h -> linux/stddef.h -> uapi/linux/stddef.h and is needed to provide a proper definition of offsetof. Unfortunately, compiler.h requires a definition of smp_read_barrier_depends() for defining lockless_dereference() and soon for defining READ_ONCE(), which means that all users of READ_ONCE() will need to include asm/barrier.h to avoid splats such as: In file included from include/uapi/linux/stddef.h:1:0, from include/linux/stddef.h:4, from arch/h8300/kernel/asm-offsets.c:11: include/linux/list.h: In function 'list_empty': >> include/linux/compiler.h:343:2: error: implicit declaration of function 'smp_read_barrier_depends' [-Werror=implicit-function-declaration] smp_read_barrier_depends(); /* Enforce dependency ordering from x */ \ ^ A better alternative is to include asm/barrier.h in linux/compiler.h, but this requires a type definition for "bool" on some architectures (e.g. x86), which is defined later by linux/types.h. Type "bool" is also used directly in linux/compiler.h, so the whole thing is pretty fragile. This patch splits compiler.h in two: compiler_types.h contains type annotations, definitions and the compiler-specific parts, whereas compiler.h #includes compiler-types.h and additionally defines macros such as {READ,WRITE.ACCESS}_ONCE(). uapi/linux/stddef.h and linux/linkage.h are then moved over to include linux/compiler_types.h, which fixes the build for h8 and blackfin. Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1508840570-22169-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-24 18:22:46 +08:00
#include <linux/compiler_types.h>
uapi/linux/stddef.h: Provide __always_inline to userspace headers Josh Boyer reported that my recent change to uapi/linux/swab.h broke the Qemu build: bc27fb68aaad ("include/uapi/linux/byteorder, swab: force inlining of some byteswap operations") Unfortunately, UAPI headers don't include compiler.h so fixing it there is not enough, add an __always_inline definition to uapi/linux/stddef.h instead. Testcase: "make headers_install" and try to compile this: #include <linux/swab.h> void main() {} Reported-by: Josh Boyer <jwboyer@fedoraproject.org> Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Rientjes <rientjes@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Graf <tgraf@suug.ch> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1459289697-12875-1-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-30 06:14:57 +08:00
#ifndef __always_inline
#define __always_inline inline
#endif