From: Thomas Gleixner Date: Tue, 2 Jun 2026 09:09:21 +0000 (+0200) Subject: percpu: Sanitize __percpu_qual include hell X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=c06cd66387da92e6cdac44e16c7b5ef9219c53ac;p=thirdparty%2Fkernel%2Flinux.git percpu: Sanitize __percpu_qual include hell Slapping __percpu_qual into the next available header is sloppy at best. It's required by __percpu which is defined in compiler_types.h and that is meant to be included without requiring a boatload of other headers so that a struct or function declaration can contain a __percpu qualifier w/o further prerequisites. This implicit dependency on linux/percpu.h makes that impossible and causes a major problem when trying to separate headers. Create asm/percpu_types.h and move it there. Include that from compiler_types.h and the whole recursion problem goes away. Fix up UM so it uses the generic header and includes it in the UM_HOST build, which pulls in compiler_types.h. The USER_CFLAGS fix was suggested by Richard. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20260602090535.254874125@kernel.org --- diff --git a/arch/um/Makefile b/arch/um/Makefile index 721b652ffb658..937639edc295e 100644 --- a/arch/um/Makefile +++ b/arch/um/Makefile @@ -71,7 +71,8 @@ USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -I%,,$(KBUILD_CFLAGS))) \ -D_FILE_OFFSET_BITS=64 -idirafter $(srctree)/include \ -idirafter $(objtree)/include -D__KERNEL__ -D__UM_HOST__ \ -include $(srctree)/include/linux/compiler-version.h \ - -include $(srctree)/include/linux/kconfig.h + -include $(srctree)/include/linux/kconfig.h \ + -idirafter $(ARCH_DIR)/include/generated #This will adjust *FLAGS accordingly to the platform. include $(srctree)/$(ARCH_DIR)/Makefile-os-Linux diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild index 1b9b82bbe3220..e91ba12b7ffc5 100644 --- a/arch/um/include/asm/Kbuild +++ b/arch/um/include/asm/Kbuild @@ -16,6 +16,7 @@ generic-y += module.h generic-y += module.lds.h generic-y += parport.h generic-y += percpu.h +generic-y += percpu_types.h generic-y += preempt.h generic-y += runtime-const.h generic-y += softirq_stack.h diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h index 409981468cba2..cef9a4ca98414 100644 --- a/arch/x86/include/asm/percpu.h +++ b/arch/x86/include/asm/percpu.h @@ -40,12 +40,10 @@ #endif #define __percpu_prefix -#define __percpu_seg_override CONCATENATE(__seg_, __percpu_seg) #else /* !CONFIG_CC_HAS_NAMED_AS: */ #define __percpu_prefix __force_percpu_prefix -#define __percpu_seg_override #endif /* CONFIG_CC_HAS_NAMED_AS */ @@ -82,7 +80,6 @@ #define __force_percpu_prefix #define __percpu_prefix -#define __percpu_seg_override #define PER_CPU_VAR(var) (var)__percpu_rel @@ -92,8 +89,6 @@ # define __my_cpu_type(var) typeof(var) # define __my_cpu_ptr(ptr) (ptr) # define __my_cpu_var(var) (var) - -# define __percpu_qual __percpu_seg_override #else # define __my_cpu_type(var) typeof(var) __percpu_seg_override # define __my_cpu_ptr(ptr) (__my_cpu_type(*(ptr))*)(__force uintptr_t)(ptr) diff --git a/arch/x86/include/asm/percpu_types.h b/arch/x86/include/asm/percpu_types.h new file mode 100644 index 0000000000000..0aa3e47a36435 --- /dev/null +++ b/arch/x86/include/asm/percpu_types.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_PERCPU_TYPES_H +#define _ASM_X86_PERCPU_TYPES_H + +#if defined(CONFIG_SMP) && defined(CONFIG_CC_HAS_NAMED_AS) +#define __percpu_seg_override CONCATENATE(__seg_, __percpu_seg) +#else /* !CONFIG_CC_HAS_NAMED_AS: */ +#define __percpu_seg_override +#endif + +#if defined(CONFIG_USE_X86_SEG_SUPPORT) && defined(USE_TYPEOF_UNQUAL) +#define __percpu_qual __percpu_seg_override +#endif + +#include + +#endif diff --git a/include/asm-generic/Kbuild b/include/asm-generic/Kbuild index 2c53a1e0b7604..15df9dcb42a5b 100644 --- a/include/asm-generic/Kbuild +++ b/include/asm-generic/Kbuild @@ -44,6 +44,7 @@ mandatory-y += module.lds.h mandatory-y += msi.h mandatory-y += pci.h mandatory-y += percpu.h +mandatory-y += percpu_types.h mandatory-y += pgalloc.h mandatory-y += preempt.h mandatory-y += rqspinlock.h diff --git a/include/asm-generic/percpu_types.h b/include/asm-generic/percpu_types.h new file mode 100644 index 0000000000000..a095cea7fa203 --- /dev/null +++ b/include/asm-generic/percpu_types.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_PERCPU_TYPES_H_ +#define _ASM_GENERIC_PERCPU_TYPES_H_ + +#ifndef __ASSEMBLER__ +/* + * __percpu_qual is the qualifier for the percpu named address space. + * + * Most architectures use generic named address space for percpu variables but + * some architectures define percpu variables in different named address space. + * E.g. on x86, percpu variable may be declared as being relative to the %fs or + * %gs segments using __seg_fs or __seg_gs named address space qualifier. + */ +#ifndef __percpu_qual +# define __percpu_qual +#endif + +#endif /* __ASSEMBLER__ */ +#endif /* _ASM_GENERIC_PERCPU_TYPES_H_ */ diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index e8fd77593b68d..7ad37adda1dda 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -634,6 +634,9 @@ struct ftrace_likely_data { #else #define __unqual_scalar_typeof(x) __typeof_unqual__(x) #endif + +#include + #endif /* !__ASSEMBLY__ */ /* diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 85bf8dd9f0874..2f5a889aa50d9 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -3,13 +3,14 @@ #define __LINUX_PERCPU_H #include +#include +#include +#include #include -#include -#include #include -#include -#include +#include #include +#include #include