Patch "arm64: fix building without CONFIG_UID16" has been added to the 3.10-stable tree

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

arm64: fix building without CONFIG_UID16

to the 3.10-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:
arm64-fix-building-without-config_uid16.patch
and it can be found in the queue-3.10 subdirectory.

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

From: Arnd Bergmann <[email protected]>
Date: Fri, 20 Nov 2015 12:12:21 +0100
Subject: arm64: fix building without CONFIG_UID16

From: Arnd Bergmann <[email protected]>

commit fbc416ff86183e2203cdf975e2881d7c164b0271 upstream.

As reported by Michal Simek, building an ARM64 kernel with CONFIG_UID16 disabled currently fails because the system call table still needs to reference the individual function entry points that are provided by kernel/sys_ni.c in this case, and the declarations are hidden inside of #ifdef CONFIG_UID16:

arch/arm64/include/asm/unistd32.h:57:8: error: 'sys_lchown16' undeclared here (not in a function)
__SYSCALL(__NR_lchown, sys_lchown16)

I believe this problem only exists on ARM64, because older architectures tend to not need declarations when their system call table is built in assembly code, while newer architectures tend to not need UID16 support. ARM64 only uses these system calls for compatibility with 32-bit ARM binaries.

This changes the CONFIG_UID16 check into CONFIG_HAVE_UID16, which is set unconditionally on ARM64 with CONFIG_COMPAT, so we see the declarations whenever we need them, but otherwise the behavior is unchanged.

---
 include/linux/syscalls.h |    2 +-
 include/linux/types.h    |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

@@ -498,7 +498,7 @@ asmlinkage long sys_chown(const char __u
 asmlinkage long sys_lchown(const char __user *filename,
 				uid_t user, gid_t group);
 asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group);
-#ifdef CONFIG_UID16
+#ifdef CONFIG_HAVE_UID16
 asmlinkage long sys_chown16(const char __user *filename,
 				old_uid_t user, old_gid_t group);
 asmlinkage long sys_lchown16(const char __user *filename,

@@ -35,7 +35,7 @@ typedef __kernel_gid16_t        gid16_t;
 
 typedef unsigned long		uintptr_t;
 
-#ifdef CONFIG_UID16
+#ifdef CONFIG_HAVE_UID16
 /* This is defined by include/asm-{arch}/posix_types.h */
 typedef __kernel_old_uid_t	old_uid_t;
 typedef __kernel_old_gid_t	old_gid_t;

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

queue-3.10/arm64-fix-building-without-config_uid16.patch

Hi Greg,

This patch caused a regression on mn10300, so please also backport the one below to fix that. I have verified again that no other architectures had the same problem beside mn10300.

Arnd

8<------

From: Guenter Roeck <[email protected]>
Date: Sat, 28 Nov 2015 08:52:04 -0800
Subject: [PATCH] mn10300: Select CONFIG_HAVE_UID16 to fix build failure

mn10300 builds fail with

fs/stat.c: In function 'cp_old_stat':
fs/stat.c:163:2: error: 'old_uid_t' undeclared

ipc/util.c: In function 'ipc64_perm_to_ipc_perm':
ipc/util.c:540:2: error: 'old_uid_t' undeclared

Select CONFIG_HAVE_UID16 and remove local definition of CONFIG_UID16 to fix the problem.

index 4434b54e1d87..78ae5552fdb8 100644
@@ -1,6 +1,7 @@
 config MN10300
 	def_bool y
 	select HAVE_OPROFILE
+	select HAVE_UID16
 	select GENERIC_IRQ_SHOW
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select HAVE_ARCH_TRACEHOOK

@@ -37,9 +38,6 @@ config HIGHMEM
 config NUMA
 	def_bool n
 
-config UID16
-	def_bool y
-
 config RWSEM_GENERIC_SPINLOCK
 	def_bool y
 

Now queued up, thanks.

greg k-h