s390/compat: convert system call wrappers to C part 01

Introduce a new compat_wrap.c file which contains the s390 specific compat
system call wrappers.
The s390 specific system call wrappers only perform sign, zero and pointer
conversion of system call arguments before actually calling the non-compat
system call.

Therefore introduce COMPAT_SYSCALL_WRAPx macros which generate C code that
is nearly identical to the assembly code. This has the advantage that the
compile will generate correct code, and we avoid the frequent copy-paste
errors seen in the compat_wrapper.S file.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

4 files changed, 48 insertions, 68 deletions

diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 1b3ac09..725515f9 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -50,6 +50,7 @@ compat-obj-$(CONFIG_AUDIT)	+= compat_audit.o
 obj-$(CONFIG_COMPAT)		+= compat_linux.o compat_signal.o \
 					compat_wrapper.o compat_exec_domain.o \
 					$(compat-obj-y)
+obj-$(CONFIG_COMPAT)		+= compat_wrap.o
 
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
diff --git a/arch/s390/kernel/compat_wrap.c b/arch/s390/kernel/compat_wrap.c
new file mode 100644
index 0000000..5357190
--- /dev/null
+++ b/arch/s390/kernel/compat_wrap.c
@@ -0,0 +1,35 @@
+#include <linux/syscalls.h>
+#include <linux/compat.h>
+
+#define COMPAT_SYSCALL_WRAP1(name, ...) \
+	COMPAT_SYSCALL_WRAPx(1, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_WRAP2(name, ...) \
+	COMPAT_SYSCALL_WRAPx(2, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_WRAP3(name, ...) \
+	COMPAT_SYSCALL_WRAPx(3, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_WRAP4(name, ...) \
+	COMPAT_SYSCALL_WRAPx(4, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_WRAP5(name, ...) \
+	COMPAT_SYSCALL_WRAPx(5, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_WRAP6(name, ...) \
+	COMPAT_SYSCALL_WRAPx(6, _##name, __VA_ARGS__)
+
+#define COMPAT_SYSCALL_WRAPx(x, name, ...)					\
+	asmlinkage long compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
+	asmlinkage long compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))	\
+	{									\
+		return sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));		\
+	}
+
+COMPAT_SYSCALL_WRAP1(exit, int, error_code);
+COMPAT_SYSCALL_WRAP1(close, unsigned int, fd);
+COMPAT_SYSCALL_WRAP2(creat, const char __user *, pathname, umode_t, mode);
+COMPAT_SYSCALL_WRAP2(link, const char __user *, oldname, const char __user *, newname);
+COMPAT_SYSCALL_WRAP1(unlink, const char __user *, pathname);
+COMPAT_SYSCALL_WRAP1(chdir, const char __user *, filename);
+COMPAT_SYSCALL_WRAP3(mknod, const char __user *, filename, umode_t, mode, unsigned, dev);
+COMPAT_SYSCALL_WRAP2(chmod, const char __user *, filename, umode_t, mode);
+COMPAT_SYSCALL_WRAP1(oldumount, char __user *, name);
+COMPAT_SYSCALL_WRAP1(alarm, unsigned int, seconds);
+COMPAT_SYSCALL_WRAP2(access, const char __user *, filename, int, mode);
+COMPAT_SYSCALL_WRAP1(nice, int, increment);
diff --git a/arch/s390/kernel/compat_wrapper.S b/arch/s390/kernel/compat_wrapper.S
index 16ce718..09e65cd 100644
--- a/arch/s390/kernel/compat_wrapper.S
+++ b/arch/s390/kernel/compat_wrapper.S
@@ -8,47 +8,10 @@
 
 #include <linux/linkage.h>
 
-ENTRY(sys32_exit_wrapper)
-	lgfr	%r2,%r2			# int
-	jg	sys_exit		# branch to sys_exit
-
-ENTRY(sys32_close_wrapper)
-	llgfr	%r2,%r2			# unsigned int
-	jg	sys_close		# branch to system call
-
-ENTRY(sys32_creat_wrapper)
-	llgtr	%r2,%r2			# const char *
-	lgfr	%r3,%r3			# int
-	jg	sys_creat		# branch to system call
-
-ENTRY(sys32_link_wrapper)
-	llgtr	%r2,%r2			# const char *
-	llgtr	%r3,%r3			# const char *
-	jg	sys_link		# branch to system call
-
-ENTRY(sys32_unlink_wrapper)
-	llgtr	%r2,%r2			# const char *
-	jg	sys_unlink		# branch to system call
-
-ENTRY(sys32_chdir_wrapper)
-	llgtr	%r2,%r2			# const char *
-	jg	sys_chdir		# branch to system call
-
 ENTRY(sys32_time_wrapper)
 	llgtr	%r2,%r2			# int *
 	jg	compat_sys_time		# branch to system call
 
-ENTRY(sys32_mknod_wrapper)
-	llgtr	%r2,%r2			# const char *
-	lgfr	%r3,%r3			# int
-	llgfr	%r4,%r4			# dev
-	jg	sys_mknod		# branch to system call
-
-ENTRY(sys32_chmod_wrapper)
-	llgtr	%r2,%r2			# const char *
-	llgfr	%r3,%r3			# mode_t
-	jg	sys_chmod		# branch to system call
-
 #sys32_getpid_wrapper				# void
 
 ENTRY(sys32_mount_wrapper)
@@ -59,10 +22,6 @@ ENTRY(sys32_mount_wrapper)
 	llgtr	%r6,%r6			# void *
 	jg	compat_sys_mount	# branch to system call
 
-ENTRY(sys32_oldumount_wrapper)
-	llgtr	%r2,%r2			# char *
-	jg	sys_oldumount		# branch to system call
-
 ENTRY(sys32_ptrace_wrapper)
 	lgfr	%r2,%r2			# long
 	lgfr	%r3,%r3			# long
@@ -70,26 +29,11 @@ ENTRY(sys32_ptrace_wrapper)
 	llgfr	%r5,%r5			# long
 	jg	compat_sys_ptrace	# branch to system call
 
-ENTRY(sys32_alarm_wrapper)
-	llgfr	%r2,%r2			# unsigned int
-	jg	sys_alarm		# branch to system call
-
 ENTRY(compat_sys_utime_wrapper)
 	llgtr	%r2,%r2			# char *
 	llgtr	%r3,%r3			# struct compat_utimbuf *
 	jg	compat_sys_utime	# branch to system call
 
-ENTRY(sys32_access_wrapper)
-	llgtr	%r2,%r2			# const char *
-	lgfr	%r3,%r3			# int
-	jg	sys_access		# branch to system call
-
-ENTRY(sys32_nice_wrapper)
-	lgfr	%r2,%r2			# int
-	jg	sys_nice		# branch to system call
-
-#sys32_sync_wrapper			# void
-
 ENTRY(sys32_kill_wrapper)
 	lgfr	%r2,%r2			# int
 	lgfr	%r3,%r3			# int
diff --git a/arch/s390/kernel/syscalls.S b/arch/s390/kernel/syscalls.S
index 5a83f6a..ec1de1b 100644
--- a/arch/s390/kernel/syscalls.S
+++ b/arch/s390/kernel/syscalls.S
@@ -9,40 +9,40 @@
 #define NI_SYSCALL SYSCALL(sys_ni_syscall,sys_ni_syscall,sys_ni_syscall)
 
 NI_SYSCALL							/* 0 */
-SYSCALL(sys_exit,sys_exit,sys32_exit_wrapper)
+SYSCALL(sys_exit,sys_exit,compat_sys_exit)
 SYSCALL(sys_fork,sys_fork,sys_fork)
 SYSCALL(sys_read,sys_read,compat_sys_s390_read)
 SYSCALL(sys_write,sys_write,compat_sys_s390_write)
 SYSCALL(sys_open,sys_open,compat_sys_open)			/* 5 */
-SYSCALL(sys_close,sys_close,sys32_close_wrapper)
+SYSCALL(sys_close,sys_close,compat_sys_close)
 SYSCALL(sys_restart_syscall,sys_restart_syscall,sys_restart_syscall)
-SYSCALL(sys_creat,sys_creat,sys32_creat_wrapper)
-SYSCALL(sys_link,sys_link,sys32_link_wrapper)
-SYSCALL(sys_unlink,sys_unlink,sys32_unlink_wrapper)		/* 10 */
+SYSCALL(sys_creat,sys_creat,compat_sys_creat)
+SYSCALL(sys_link,sys_link,compat_sys_link)
+SYSCALL(sys_unlink,sys_unlink,compat_sys_unlink)		/* 10 */
 SYSCALL(sys_execve,sys_execve,sys32_execve_wrapper)
-SYSCALL(sys_chdir,sys_chdir,sys32_chdir_wrapper)
+SYSCALL(sys_chdir,sys_chdir,compat_sys_chdir)
 SYSCALL(sys_time,sys_ni_syscall,sys32_time_wrapper)		/* old time syscall */
-SYSCALL(sys_mknod,sys_mknod,sys32_mknod_wrapper)
-SYSCALL(sys_chmod,sys_chmod,sys32_chmod_wrapper)		/* 15 */
+SYSCALL(sys_mknod,sys_mknod,compat_sys_mknod)
+SYSCALL(sys_chmod,sys_chmod,compat_sys_chmod)			/* 15 */
 SYSCALL(sys_lchown16,sys_ni_syscall,compat_sys_s390_lchown16)	/* old lchown16 syscall*/
 NI_SYSCALL							/* old break syscall holder */
 NI_SYSCALL							/* old stat syscall holder */
 SYSCALL(sys_lseek,sys_lseek,compat_sys_lseek)
 SYSCALL(sys_getpid,sys_getpid,sys_getpid)			/* 20 */
 SYSCALL(sys_mount,sys_mount,sys32_mount_wrapper)
-SYSCALL(sys_oldumount,sys_oldumount,sys32_oldumount_wrapper)
+SYSCALL(sys_oldumount,sys_oldumount,compat_sys_oldumount)
 SYSCALL(sys_setuid16,sys_ni_syscall,compat_sys_s390_setuid16)	/* old setuid16 syscall*/
 SYSCALL(sys_getuid16,sys_ni_syscall,compat_sys_s390_getuid16)	/* old getuid16 syscall*/
 SYSCALL(sys_stime,sys_ni_syscall,sys32_stime_wrapper)		/* 25 old stime syscall */
 SYSCALL(sys_ptrace,sys_ptrace,sys32_ptrace_wrapper)
-SYSCALL(sys_alarm,sys_alarm,sys32_alarm_wrapper)
+SYSCALL(sys_alarm,sys_alarm,compat_sys_alarm)
 NI_SYSCALL							/* old fstat syscall */
 SYSCALL(sys_pause,sys_pause,sys_pause)
 SYSCALL(sys_utime,sys_utime,compat_sys_utime_wrapper)		/* 30 */
 NI_SYSCALL							/* old stty syscall */
 NI_SYSCALL							/* old gtty syscall */
-SYSCALL(sys_access,sys_access,sys32_access_wrapper)
-SYSCALL(sys_nice,sys_nice,sys32_nice_wrapper)
+SYSCALL(sys_access,sys_access,compat_sys_access)
+SYSCALL(sys_nice,sys_nice,compat_sys_nice)
 NI_SYSCALL							/* 35 old ftime syscall */
 SYSCALL(sys_sync,sys_sync,sys_sync)
 SYSCALL(sys_kill,sys_kill,sys32_kill_wrapper)