improve sys_newuname() for compat architectures

On an architecture that supports 32-bit compat we need to override the
reported machine in uname with the 32-bit value.  Instead of doing this
separately in every architecture introduce a COMPAT_UTS_MACHINE define in
<asm/compat.h> and apply it directly in sys_newuname().

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 4 insertions, 16 deletions

diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h
index 01a0802..104f200 100644
--- a/arch/s390/include/asm/compat.h
+++ b/arch/s390/include/asm/compat.h
@@ -35,7 +35,8 @@
 
 extern long psw32_user_bits;
 
-#define COMPAT_USER_HZ	100
+#define COMPAT_USER_HZ		100
+#define COMPAT_UTS_MACHINE	"s390\0\0\0\0"
 
 typedef u32		compat_size_t;
 typedef s32		compat_ssize_t;
diff --git a/arch/s390/kernel/compat_wrapper.S b/arch/s390/kernel/compat_wrapper.S
index 30de2d0..672ce52 100644
--- a/arch/s390/kernel/compat_wrapper.S
+++ b/arch/s390/kernel/compat_wrapper.S
@@ -547,7 +547,7 @@ sys32_setdomainname_wrapper:
 	.globl	sys32_newuname_wrapper
 sys32_newuname_wrapper:
 	llgtr	%r2,%r2			# struct new_utsname *
-	jg	sys_s390_newuname	# branch to system call
+	jg	sys_newuname		# branch to system call
 
 	.globl	compat_sys_adjtimex_wrapper
 compat_sys_adjtimex_wrapper:
diff --git a/arch/s390/kernel/entry.h b/arch/s390/kernel/entry.h
index 15fd68b..eb15c12 100644
--- a/arch/s390/kernel/entry.h
+++ b/arch/s390/kernel/entry.h
@@ -24,7 +24,6 @@ int __cpuinit start_secondary(void *cpuvoid);
 void __init startup_init(void);
 void die(const char * str, struct pt_regs * regs, long err);
 
-struct new_utsname;
 struct s390_mmap_arg_struct;
 struct fadvise64_64_args;
 struct old_sigaction;
@@ -32,7 +31,6 @@ struct old_sigaction;
 long sys_mmap2(struct s390_mmap_arg_struct __user  *arg);
 long sys_s390_ipc(uint call, int first, unsigned long second,
 	     unsigned long third, void __user *ptr);
-long sys_s390_newuname(struct new_utsname __user *name);
 long sys_s390_personality(unsigned long personality);
 long sys_s390_fadvise64(int fd, u32 offset_high, u32 offset_low,
 		    size_t len, int advice);
diff --git a/arch/s390/kernel/sys_s390.c b/arch/s390/kernel/sys_s390.c
index b8b7809..7b6b0f8 100644
--- a/arch/s390/kernel/sys_s390.c
+++ b/arch/s390/kernel/sys_s390.c
@@ -131,17 +131,6 @@ SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,
 }
 
 #ifdef CONFIG_64BIT
-SYSCALL_DEFINE1(s390_newuname, struct new_utsname __user *, name)
-{
-	int ret = sys_newuname(name);
-
-	if (personality(current->personality) == PER_LINUX32 && !ret) {
-		ret = copy_to_user(name->machine, "s390\0\0\0\0", 8);
-		if (ret) ret = -EFAULT;
-	}
-	return ret;
-}
-
 SYSCALL_DEFINE1(s390_personality, unsigned long, personality)
 {
 	int ret;
diff --git a/arch/s390/kernel/syscalls.S b/arch/s390/kernel/syscalls.S
index 990ac8b..201ce6b 100644
--- a/arch/s390/kernel/syscalls.S
+++ b/arch/s390/kernel/syscalls.S
@@ -130,7 +130,7 @@ SYSCALL(sys_fsync,sys_fsync,sys32_fsync_wrapper)
 SYSCALL(sys_sigreturn,sys_sigreturn,sys32_sigreturn)
 SYSCALL(sys_clone,sys_clone,sys_clone_wrapper)			/* 120 */
 SYSCALL(sys_setdomainname,sys_setdomainname,sys32_setdomainname_wrapper)
-SYSCALL(sys_newuname,sys_s390_newuname,sys32_newuname_wrapper)
+SYSCALL(sys_newuname,sys_newuname,sys32_newuname_wrapper)
 NI_SYSCALL							/* modify_ldt for i386 */
 SYSCALL(sys_adjtimex,sys_adjtimex,compat_sys_adjtimex_wrapper)
 SYSCALL(sys_mprotect,sys_mprotect,sys32_mprotect_wrapper)	/* 125 */