Patch "linux/compiler.h: Split into compiler.h and compiler_types.h" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

linux/compiler.h: Split into compiler.h and compiler_types.h

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
linux-compiler.h-split-into-compiler.h-and-compiler_types.h.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Will Deacon <[email protected]>
Date: Tue, 24 Oct 2017 11:22:46 +0100
Subject: linux/compiler.h: Split into compiler.h and compiler_types.h

From: Will Deacon <[email protected]>

commit d15155824c5014803d91b829736d249c500bdda6 upstream.

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':

     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.

---
 arch/arm/include/asm/ptrace.h   |    3 
 arch/sparc/include/asm/ptrace.h |    1 
 arch/um/include/shared/init.h   |    2 
 include/linux/compiler-clang.h  |    2 
 include/linux/compiler-gcc.h    |    2 
 include/linux/compiler-intel.h  |    2 
 include/linux/compiler.h        |  265 --------------------------------------
 include/linux/compiler_types.h  |  274 ++++++++++++++++++++++++++++++++++++++++
 include/linux/linkage.h         |    2 
 include/uapi/linux/stddef.h     |    2 
 scripts/headers_install.sh      |    2 
 11 files changed, 286 insertions(+), 271 deletions(-)

@@ -126,8 +126,7 @@ extern unsigned long profile_pc(struct p
 /*
  * kprobe-based event tracer support
  */
-#include <linux/stddef.h>
-#include <linux/types.h>
+#include <linux/compiler.h>
 #define MAX_REG_OFFSET (offsetof(struct pt_regs, ARM_ORIG_r0))
 
 extern int regs_query_register_offset(const char *name);

@@ -7,6 +7,7 @@
 #if defined(__sparc__) && defined(__arch64__)
 #ifndef __ASSEMBLY__
 
+#include <linux/compiler.h>
 #include <linux/threads.h>
 #include <asm/switch_to.h>
 

@@ -41,7 +41,7 @@
 typedef int (*initcall_t)(void);
 typedef void (*exitcall_t)(void);
 
-#include <linux/compiler.h>
+#include <linux/compiler_types.h>
 
 /* These are for everybody (although not all archs will actually
    discard it in modules) */

@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __LINUX_COMPILER_H
+#ifndef __LINUX_COMPILER_TYPES_H
 #error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead."
 #endif
 

@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __LINUX_COMPILER_H
+#ifndef __LINUX_COMPILER_TYPES_H
 #error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
 #endif
 

@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __LINUX_COMPILER_H
+#ifndef __LINUX_COMPILER_TYPES_H
 #error "Please don't include <linux/compiler-intel.h> directly, include <linux/compiler.h> instead."
 #endif
 

@@ -2,7 +2,7 @@
 #ifndef _LINUX_LINKAGE_H
 #define _LINUX_LINKAGE_H
 
-#include <linux/compiler.h>
+#include <linux/compiler_types.h>
 #include <linux/stringify.h>
 #include <linux/export.h>
 #include <asm/linkage.h>

@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#include <linux/compiler.h>
+#include <linux/compiler_types.h>
 
 #ifndef __always_inline
 #define __always_inline inline

@@ -34,7 +34,7 @@ do
 	sed -r \
 		-e 's/([ \t(])(__user|__force|__iomem)[ \t]/\1/g' \
 		-e 's/__attribute_const__([ \t]|$)/\1/g' \
-		-e 's@^#include <linux/compiler.h>@@' \
+		-e 's@^#include <linux/compiler(|_types).h>@@' \
 		-e 's/(^|[^a-zA-Z0-9])__packed([^a-zA-Z0-9_]|$)/\1__attribute__((packed))\2/g' \
 		-e 's/(^|[ \t(])(inline|asm|volatile)([ \t(]|$)/\1__\2__\3/g' \
 		-e 's@#(ifndef|define|endif[ \t]*/[*])[ \t]*_UAPI@#\1 @' \

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/locking-barriers-add-implicit-smp_read_barrier_depends-to-read_once.patch queue-4.14/mm-sparsemem-fix-arm64-boot-crash-when-config_sparsemem_extreme-y.patch queue-4.14/linux-compiler.h-split-into-compiler.h-and-compiler_types.h.patch queue-4.14/x86-entry-64-move-the-ist-stacks-into-struct-cpu_entry_area.patch queue-4.14/x86-dumpstack-add-get_stack_info-support-for-the-sysenter-stack.patch queue-4.14/x86-entry-remap-the-tss-into-the-cpu-entry-area.patch queue-4.14/x86-entry-64-paravirt-use-paravirt-safe-macro-to-access-eflags.patch queue-4.14/x86-mm-fixmap-generalize-the-gdt-fixmap-mechanism-introduce-struct-cpu_entry_area.patch queue-4.14/x86-paravirt-dont-patch-flush_tlb_single.patch queue-4.14/locking-barriers-convert-users-of-lockless_dereference-to-read_once.patch queue-4.14/x86-dumpstack-handle-stack-overflow-on-all-stacks.patch queue-4.14/x86-entry-64-return-to-userspace-from-the-trampoline-stack.patch queue-4.14/x86-paravirt-provide-a-way-to-check-for-hypervisors.patch queue-4.14/x86-entry-64-create-a-per-cpu-syscall-entry-trampoline.patch queue-4.14/x86-entry-64-use-a-per-cpu-trampoline-stack-for-idt-entries.patch queue-4.14/acpi-apei-replace-ioremap_page_range-with-fixmap.patch queue-4.14/x86-cpufeatures-make-cpu-bugs-sticky.patch queue-4.14/x86-espfix-64-stop-assuming-that-pt_regs-is-on-the-entry-stack.patch queue-4.14/x86-entry-move-sysenter_stack-to-the-beginning-of-struct-tss_struct.patch queue-4.14/x86-entry-64-allocate-and-enable-the-sysenter-stack.patch queue-4.14/x86-unwinder-orc-dont-bail-on-stack-overflow.patch queue-4.14/x86-kasan-64-teach-kasan-about-the-cpu_entry_area.patch queue-4.14/x86-entry-64-remove-the-sysenter-stack-canary.patch queue-4.14/x86-mm-kasan-don-t-use-vmemmap_populate-to-initialize-shadow.patch queue-4.14/x86-entry-gdt-put-per-cpu-gdt-remaps-in-ascending-order.patch queue-4.14/x86-entry-fix-assumptions-that-the-hw-tss-is-at-the-beginning-of-cpu_tss.patch queue-4.14/x86-entry-64-make-cpu_entry_area.tss-read-only.patch queue-4.14/x86-unwinder-handle-stack-overflows-more-gracefully.patch queue-4.14/x86-irq-64-print-the-offending-ip-in-the-stack-overflow-warning.patch queue-4.14/x86-entry-clean-up-the-sysenter_stack-code.patch queue-4.14/x86-entry-64-separate-cpu_current_top_of_stack-from-tss.sp0.patch queue-4.14/x86-irq-remove-an-old-outdated-comment-about-context-tracking-races.patch