[S390] Add missing compat system call wrappers.

Add wrapper functions for the following compat system calls:
* readahead
* sendfile64
* tkill
* tgkill
* keyctl
This ensures that the high order bits of the parameter registers are correctly
sign extended.

Signed-off-by: Michael Holzheu <[e-mail]>
Signed-off-by: Heiko Carstens <[e-mail]>

arch/s390/kernel/compat_wrapper.S

···
 sys_epoll_create1_wrapper:
 	lgfr	%r2,%r2			# int
 	jg	sys_epoll_create1	# branch to system call
+
+	.globl	sys32_readahead_wrapper
+sys32_readahead_wrapper:
+	lgfr	%r2,%r2			# int
+	llgfr	%r3,%r3			# u32
+	llgfr	%r4,%r4			# u32
+	lgfr	%r5,%r5			# s32
+	jg	sys32_readahead		# branch to system call
+
+	.globl	sys32_sendfile64_wrapper
+sys32_sendfile64_wrapper:
+	lgfr	%r2,%r2			# int
+	lgfr	%r3,%r3			# int
+	llgtr	%r4,%r4			# compat_loff_t *
+	lgfr	%r5,%r5			# s32
+	jg	sys32_sendfile64	# branch to system call
+
+	.globl	sys_tkill_wrapper
+sys_tkill_wrapper:
+	lgfr	%r2,%r2			# pid_t
+	lgfr	%r3,%r3			# int
+	jg	sys_tkill		# branch to system call
+
+	.globl	sys_tgkill_wrapper
+sys_tgkill_wrapper:
+	lgfr	%r2,%r2			# pid_t
+	lgfr	%r3,%r3			# pid_t
+	lgfr	%r4,%r4			# int
+	jg	sys_tgkill		# branch to system call
+
+	.globl	compat_sys_keyctl_wrapper
+compat_sys_keyctl_wrapper:
+	llgfr	%r2,%r2			# u32
+	llgfr	%r3,%r3			# u32
+	llgfr	%r4,%r4			# u32
+	llgfr	%r5,%r5			# u32
+	llgfr	%r6,%r6			# u32
+	jg	compat_sys_keyctl	# branch to system call

arch/s390/kernel/syscalls.S

···
 SYSCALL(sys_madvise,sys_madvise,sys32_madvise_wrapper)
 SYSCALL(sys_getdents64,sys_getdents64,sys32_getdents64_wrapper)	/* 220 */
 SYSCALL(sys_fcntl64,sys_ni_syscall,compat_sys_fcntl64_wrapper)
-SYSCALL(sys_readahead,sys_readahead,sys32_readahead)
-SYSCALL(sys_sendfile64,sys_ni_syscall,sys32_sendfile64)
+SYSCALL(sys_readahead,sys_readahead,sys32_readahead_wrapper)
+SYSCALL(sys_sendfile64,sys_ni_syscall,sys32_sendfile64_wrapper)
 SYSCALL(sys_setxattr,sys_setxattr,sys32_setxattr_wrapper)
 SYSCALL(sys_lsetxattr,sys_lsetxattr,sys32_lsetxattr_wrapper)	/* 225 */
 SYSCALL(sys_fsetxattr,sys_fsetxattr,sys32_fsetxattr_wrapper)
···
 SYSCALL(sys_lremovexattr,sys_lremovexattr,sys32_lremovexattr_wrapper)
 SYSCALL(sys_fremovexattr,sys_fremovexattr,sys32_fremovexattr_wrapper)	/* 235 */
 SYSCALL(sys_gettid,sys_gettid,sys_gettid)
-SYSCALL(sys_tkill,sys_tkill,sys_tkill)
+SYSCALL(sys_tkill,sys_tkill,sys_tkill_wrapper)
 SYSCALL(sys_futex,sys_futex,compat_sys_futex_wrapper)
 SYSCALL(sys_sched_setaffinity,sys_sched_setaffinity,sys32_sched_setaffinity_wrapper)
 SYSCALL(sys_sched_getaffinity,sys_sched_getaffinity,sys32_sched_getaffinity_wrapper)	/* 240 */
-SYSCALL(sys_tgkill,sys_tgkill,sys_tgkill)
+SYSCALL(sys_tgkill,sys_tgkill,sys_tgkill_wrapper)
 NI_SYSCALL							/* reserved for TUX */
 SYSCALL(sys_io_setup,sys_io_setup,sys32_io_setup_wrapper)
 SYSCALL(sys_io_destroy,sys_io_destroy,sys32_io_destroy_wrapper)
···
 SYSCALL(sys_kexec_load,sys_kexec_load,compat_sys_kexec_load_wrapper)
 SYSCALL(sys_add_key,sys_add_key,compat_sys_add_key_wrapper)
 SYSCALL(sys_request_key,sys_request_key,compat_sys_request_key_wrapper)
-SYSCALL(sys_keyctl,sys_keyctl,compat_sys_keyctl)		/* 280 */
+SYSCALL(sys_keyctl,sys_keyctl,compat_sys_keyctl_wrapper)		/* 280 */
 SYSCALL(sys_waitid,sys_waitid,compat_sys_waitid_wrapper)
 SYSCALL(sys_ioprio_set,sys_ioprio_set,sys_ioprio_set_wrapper)
 SYSCALL(sys_ioprio_get,sys_ioprio_get,sys_ioprio_get_wrapper)