Merge branch 'compat' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux into features

Pull tip branch with Arnds compat system call wrapper rework.

arch/s390/Kconfig

@@ -75,6 +75,7 @@ config S390
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_STRICT_KERNEL_RWX
 	select ARCH_HAS_STRICT_MODULE_RWX
+	select ARCH_HAS_SYSCALL_WRAPPER
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_INLINE_READ_LOCK
@@ -379,6 +380,7 @@ config COMPAT
 	select COMPAT_BINFMT_ELF if BINFMT_ELF
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select COMPAT_OLD_SIGACTION
+	select HAVE_UID16
 	depends on MULTIUSER
 	help
 	  Select this option if you want to enable your system kernel to

arch/s390/include/asm/ftrace.h

@@ -81,5 +81,30 @@ static inline void ftrace_generate_call_insn(struct ftrace_insn *insn,
 #endif
 }
 
+/*
+ * Even though the system call numbers are identical for s390/s390x a
+ * different system call table is used for compat tasks. This may lead
+ * to e.g. incorrect or missing trace event sysfs files.
+ * Therefore simply do not trace compat system calls at all.
+ * See kernel/trace/trace_syscalls.c.
+ */
+#define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
+static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
+{
+	return is_compat_task();
+}
+
+#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
+static inline bool arch_syscall_match_sym_name(const char *sym,
+					       const char *name)
+{
+	/*
+	 * Skip __s390_ and __s390x_ prefix - due to compat wrappers
+	 * and aliasing some symbols of 64 bit system call functions
+	 * may get the __s390_ prefix instead of the __s390x_ prefix.
+	 */
+	return !strcmp(sym + 7, name) || !strcmp(sym + 8, name);
+}
+
 #endif /* __ASSEMBLY__ */
 #endif /* _ASM_S390_FTRACE_H */

arch/s390/include/asm/syscall_wrapper.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * syscall_wrapper.h - s390 specific wrappers to syscall definitions
+ *
+ */
+
+#ifndef _ASM_S390_SYSCALL_WRAPPER_H
+#define _ASM_S390_SYSCALL_WRAPPER_H
+
+#ifdef CONFIG_COMPAT
+#define __SC_COMPAT_TYPE(t, a) \
+	__typeof(__builtin_choose_expr(sizeof(t) > 4, 0L, (t)0)) a
+
+#define __SC_COMPAT_CAST(t, a)						\
+({									\
+	long __ReS = a;							\
+									\
+	BUILD_BUG_ON((sizeof(t) > 4) && !__TYPE_IS_L(t) &&		\
+		     !__TYPE_IS_UL(t) && !__TYPE_IS_PTR(t) &&		\
+		     !__TYPE_IS_LL(t));					\
+	if (__TYPE_IS_L(t))						\
+		__ReS = (s32)a;						\
+	if (__TYPE_IS_UL(t))						\
+		__ReS = (u32)a;						\
+	if (__TYPE_IS_PTR(t))						\
+		__ReS = a & 0x7fffffff;					\
+	if (__TYPE_IS_LL(t))						\
+		return -ENOSYS;						\
+	(t)__ReS;							\
+})
+
+#define __S390_SYS_STUBx(x, name, ...)					\
+	asmlinkage long __s390_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))\
+	ALLOW_ERROR_INJECTION(__s390_sys##name, ERRNO);			\
+	asmlinkage long __s390_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))\
+	{								\
+		long ret = __s390x_sys##name(__MAP(x,__SC_COMPAT_CAST,__VA_ARGS__));\
+		__MAP(x,__SC_TEST,__VA_ARGS__);				\
+		return ret;						\
+	}
+
+/*
+ * To keep the naming coherent, re-define SYSCALL_DEFINE0 to create an alias
+ * named __s390x_sys_*()
+ */
+#define COMPAT_SYSCALL_DEFINE0(sname)					\
+	SYSCALL_METADATA(_##sname, 0);					\
+	asmlinkage long __s390_compat_sys_##sname(void);		\
+	ALLOW_ERROR_INJECTION(__s390_compat__sys_##sname, ERRNO);	\
+	asmlinkage long __s390_compat_sys_##sname(void)
+
+#define SYSCALL_DEFINE0(sname)						\
+	SYSCALL_METADATA(_##sname, 0);					\
+	asmlinkage long __s390x_sys_##sname(void);			\
+	ALLOW_ERROR_INJECTION(__s390x_sys_##sname, ERRNO);		\
+	asmlinkage long __s390_sys_##sname(void)			\
+		__attribute__((alias(__stringify(__s390x_sys_##sname)))); \
+	asmlinkage long __s390x_sys_##sname(void)
+
+#define COND_SYSCALL(name)						\
+	cond_syscall(__s390x_sys_##name);				\
+	cond_syscall(__s390_sys_##name)
+
+#define SYS_NI(name)							\
+	SYSCALL_ALIAS(__s390x_sys_##name, sys_ni_posix_timers);		\
+	SYSCALL_ALIAS(__s390_sys_##name, sys_ni_posix_timers)
+
+#define COMPAT_SYSCALL_DEFINEx(x, name, ...)					\
+	__diag_push();								\
+	__diag_ignore(GCC, 8, "-Wattribute-alias",				\
+		      "Type aliasing is used to sanitize syscall arguments");\
+	asmlinkage long __s390_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
+	asmlinkage long __s390_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))	\
+		__attribute__((alias(__stringify(__se_compat_sys##name))));	\
+	ALLOW_ERROR_INJECTION(compat_sys##name, ERRNO);				\
+	static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
+	asmlinkage long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
+	asmlinkage long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))	\
+	{									\
+		long ret = __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));\
+		__MAP(x,__SC_TEST,__VA_ARGS__);					\
+		return ret;							\
+	}									\
+	__diag_pop();								\
+	static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+
+/*
+ * As some compat syscalls may not be implemented, we need to expand
+ * COND_SYSCALL_COMPAT in kernel/sys_ni.c and COMPAT_SYS_NI in
+ * kernel/time/posix-stubs.c to cover this case as well.
+ */
+#define COND_SYSCALL_COMPAT(name)					\
+	cond_syscall(__s390_compat_sys_##name)
+
+#define COMPAT_SYS_NI(name)						\
+	SYSCALL_ALIAS(__s390_compat_sys_##name, sys_ni_posix_timers)
+
+#else /* CONFIG_COMPAT */
+
+#define __S390_SYS_STUBx(x, fullname, name, ...)
+
+#define SYSCALL_DEFINE0(sname)						\
+	SYSCALL_METADATA(_##sname, 0);					\
+	asmlinkage long __s390x_sys_##sname(void);			\
+	ALLOW_ERROR_INJECTION(__s390x_sys_##sname, ERRNO);		\
+	asmlinkage long __s390x_sys_##sname(void)
+
+#define COND_SYSCALL(name)						\
+	cond_syscall(__s390x_sys_##name)
+
+#define SYS_NI(name)							\
+	SYSCALL_ALIAS(__s390x_sys_##name, sys_ni_posix_timers);
+
+#endif /* CONFIG_COMPAT */
+
+#define __SYSCALL_DEFINEx(x, name, ...)						\
+	__diag_push();								\
+	__diag_ignore(GCC, 8, "-Wattribute-alias",				\
+		      "Type aliasing is used to sanitize syscall arguments");\
+	asmlinkage long __s390x_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))	\
+		__attribute__((alias(__stringify(__se_sys##name))));		\
+	ALLOW_ERROR_INJECTION(__s390x_sys##name, ERRNO);				\
+	static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__));		\
+	static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
+	__S390_SYS_STUBx(x, name, __VA_ARGS__)					\
+	asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))		\
+	{									\
+		long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__));	\
+		__MAP(x,__SC_TEST,__VA_ARGS__);					\
+		return ret;							\
+	}									\
+	__diag_pop();								\
+	static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+
+#endif /* _ASM_X86_SYSCALL_WRAPPER_H */

arch/s390/include/uapi/asm/posix_types.h

@@ -20,6 +20,12 @@ typedef long            __kernel_ssize_t;
 typedef unsigned short	__kernel_old_dev_t;
 #define __kernel_old_dev_t __kernel_old_dev_t
 
+#ifdef __KERNEL__
+typedef unsigned short __kernel_old_uid_t;
+typedef unsigned short __kernel_old_gid_t;
+#define __kernel_old_uid_t __kernel_old_uid_t
+#endif
+
 #ifndef __s390x__
 
 typedef unsigned long   __kernel_ino_t;

arch/s390/kernel/Makefile

@@ -65,7 +65,7 @@ obj-$(CONFIG_HIBERNATION)	+= suspend.o swsusp.o
 obj-$(CONFIG_AUDIT)		+= audit.o
 compat-obj-$(CONFIG_AUDIT)	+= compat_audit.o
 obj-$(CONFIG_COMPAT)		+= compat_linux.o compat_signal.o
-obj-$(CONFIG_COMPAT)		+= compat_wrapper.o $(compat-obj-y)
+obj-$(CONFIG_COMPAT)		+= $(compat-obj-y)
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o

arch/s390/kernel/compat_linux.c

@@ -34,7 +34,6 @@
 #include <linux/stat.h>
 #include <linux/filter.h>
 #include <linux/highmem.h>
-#include <linux/highuid.h>
 #include <linux/mman.h>
 #include <linux/ipv6.h>
 #include <linux/in.h>
@@ -58,245 +57,13 @@
 
 #include "compat_linux.h"
 
-/* For this source file, we want overflow handling. */
-
-#undef high2lowuid
-#undef high2lowgid
-#undef low2highuid
-#undef low2highgid
-#undef SET_UID16
-#undef SET_GID16
-#undef NEW_TO_OLD_UID
-#undef NEW_TO_OLD_GID
-#undef SET_OLDSTAT_UID
-#undef SET_OLDSTAT_GID
-#undef SET_STAT_UID
-#undef SET_STAT_GID
-
-#define high2lowuid(uid) ((uid) > 65535) ? (u16)overflowuid : (u16)(uid)
-#define high2lowgid(gid) ((gid) > 65535) ? (u16)overflowgid : (u16)(gid)
-#define low2highuid(uid) ((uid) == (u16)-1) ? (uid_t)-1 : (uid_t)(uid)
-#define low2highgid(gid) ((gid) == (u16)-1) ? (gid_t)-1 : (gid_t)(gid)
-#define SET_UID16(var, uid)	var = high2lowuid(uid)
-#define SET_GID16(var, gid)	var = high2lowgid(gid)
-#define NEW_TO_OLD_UID(uid)	high2lowuid(uid)
-#define NEW_TO_OLD_GID(gid)	high2lowgid(gid)
-#define SET_OLDSTAT_UID(stat, uid)	(stat).st_uid = high2lowuid(uid)
-#define SET_OLDSTAT_GID(stat, gid)	(stat).st_gid = high2lowgid(gid)
-#define SET_STAT_UID(stat, uid)		(stat).st_uid = high2lowuid(uid)
-#define SET_STAT_GID(stat, gid)		(stat).st_gid = high2lowgid(gid)
-
-COMPAT_SYSCALL_DEFINE3(s390_chown16, const char __user *, filename,
-		       u16, user, u16, group)
-{
-	return ksys_chown(filename, low2highuid(user), low2highgid(group));
-}
-
-COMPAT_SYSCALL_DEFINE3(s390_lchown16, const char __user *,
-		       filename, u16, user, u16, group)
-{
-	return ksys_lchown(filename, low2highuid(user), low2highgid(group));
-}
-
-COMPAT_SYSCALL_DEFINE3(s390_fchown16, unsigned int, fd, u16, user, u16, group)
-{
-	return ksys_fchown(fd, low2highuid(user), low2highgid(group));
-}
-
-COMPAT_SYSCALL_DEFINE2(s390_setregid16, u16, rgid, u16, egid)
-{
-	return sys_setregid(low2highgid(rgid), low2highgid(egid));
-}
-
-COMPAT_SYSCALL_DEFINE1(s390_setgid16, u16, gid)
-{
-	return sys_setgid(low2highgid(gid));
-}
-
-COMPAT_SYSCALL_DEFINE2(s390_setreuid16, u16, ruid, u16, euid)
-{
-	return sys_setreuid(low2highuid(ruid), low2highuid(euid));
-}
-
-COMPAT_SYSCALL_DEFINE1(s390_setuid16, u16, uid)
-{
-	return sys_setuid(low2highuid(uid));
-}
-
-COMPAT_SYSCALL_DEFINE3(s390_setresuid16, u16, ruid, u16, euid, u16, suid)
-{
-	return sys_setresuid(low2highuid(ruid), low2highuid(euid),
-			     low2highuid(suid));
-}
-
-COMPAT_SYSCALL_DEFINE3(s390_getresuid16, u16 __user *, ruidp,
-		       u16 __user *, euidp, u16 __user *, suidp)
-{
-	const struct cred *cred = current_cred();
-	int retval;
-	u16 ruid, euid, suid;
-
-	ruid = high2lowuid(from_kuid_munged(cred->user_ns, cred->uid));
-	euid = high2lowuid(from_kuid_munged(cred->user_ns, cred->euid));
-	suid = high2lowuid(from_kuid_munged(cred->user_ns, cred->suid));
-
-	if (!(retval   = put_user(ruid, ruidp)) &&
-	    !(retval   = put_user(euid, euidp)))
-		retval = put_user(suid, suidp);
-
-	return retval;
-}
-
-COMPAT_SYSCALL_DEFINE3(s390_setresgid16, u16, rgid, u16, egid, u16, sgid)
-{
-	return sys_setresgid(low2highgid(rgid), low2highgid(egid),
-			     low2highgid(sgid));
-}
-
-COMPAT_SYSCALL_DEFINE3(s390_getresgid16, u16 __user *, rgidp,
-		       u16 __user *, egidp, u16 __user *, sgidp)
-{
-	const struct cred *cred = current_cred();
-	int retval;
-	u16 rgid, egid, sgid;
-
-	rgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->gid));
-	egid = high2lowgid(from_kgid_munged(cred->user_ns, cred->egid));
-	sgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->sgid));
-
-	if (!(retval   = put_user(rgid, rgidp)) &&
-	    !(retval   = put_user(egid, egidp)))
-		retval = put_user(sgid, sgidp);
-
-	return retval;
-}
-
-COMPAT_SYSCALL_DEFINE1(s390_setfsuid16, u16, uid)
-{
-	return sys_setfsuid(low2highuid(uid));
-}
-
-COMPAT_SYSCALL_DEFINE1(s390_setfsgid16, u16, gid)
-{
-	return sys_setfsgid(low2highgid(gid));
-}
-
-static int groups16_to_user(u16 __user *grouplist, struct group_info *group_info)
-{
-	struct user_namespace *user_ns = current_user_ns();
-	int i;
-	u16 group;
-	kgid_t kgid;
-
-	for (i = 0; i < group_info->ngroups; i++) {
-		kgid = group_info->gid[i];
-		group = (u16)from_kgid_munged(user_ns, kgid);
-		if (put_user(group, grouplist+i))
-			return -EFAULT;
-	}
-
-	return 0;
-}
-
-static int groups16_from_user(struct group_info *group_info, u16 __user *grouplist)
-{
-	struct user_namespace *user_ns = current_user_ns();
-	int i;
-	u16 group;
-	kgid_t kgid;
-
-	for (i = 0; i < group_info->ngroups; i++) {
-		if (get_user(group, grouplist+i))
-			return  -EFAULT;
-
-		kgid = make_kgid(user_ns, (gid_t)group);
-		if (!gid_valid(kgid))
-			return -EINVAL;
-
-		group_info->gid[i] = kgid;
-	}
-
-	return 0;
-}
-
-COMPAT_SYSCALL_DEFINE2(s390_getgroups16, int, gidsetsize, u16 __user *, grouplist)
-{
-	const struct cred *cred = current_cred();
-	int i;
-
-	if (gidsetsize < 0)
-		return -EINVAL;
-
-	get_group_info(cred->group_info);
-	i = cred->group_info->ngroups;
-	if (gidsetsize) {
-		if (i > gidsetsize) {
-			i = -EINVAL;
-			goto out;
-		}
-		if (groups16_to_user(grouplist, cred->group_info)) {
-			i = -EFAULT;
-			goto out;
-		}
-	}
-out:
-	put_group_info(cred->group_info);
-	return i;
-}
-
-COMPAT_SYSCALL_DEFINE2(s390_setgroups16, int, gidsetsize, u16 __user *, grouplist)
-{
-	struct group_info *group_info;
-	int retval;
-
-	if (!may_setgroups())
-		return -EPERM;
-	if ((unsigned)gidsetsize > NGROUPS_MAX)
-		return -EINVAL;
-
-	group_info = groups_alloc(gidsetsize);
-	if (!group_info)
-		return -ENOMEM;
-	retval = groups16_from_user(group_info, grouplist);
-	if (retval) {
-		put_group_info(group_info);
-		return retval;
-	}
-
-	groups_sort(group_info);
-	retval = set_current_groups(group_info);
-	put_group_info(group_info);
-
-	return retval;
-}
-
-COMPAT_SYSCALL_DEFINE0(s390_getuid16)
-{
-	return high2lowuid(from_kuid_munged(current_user_ns(), current_uid()));
-}
-
-COMPAT_SYSCALL_DEFINE0(s390_geteuid16)
-{
-	return high2lowuid(from_kuid_munged(current_user_ns(), current_euid()));
-}
-
-COMPAT_SYSCALL_DEFINE0(s390_getgid16)
-{
-	return high2lowgid(from_kgid_munged(current_user_ns(), current_gid()));
-}
-
-COMPAT_SYSCALL_DEFINE0(s390_getegid16)
-{
-	return high2lowgid(from_kgid_munged(current_user_ns(), current_egid()));
-}
-
 #ifdef CONFIG_SYSVIPC
 COMPAT_SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, compat_ulong_t, second,
 		compat_ulong_t, third, compat_uptr_t, ptr)
 {
 	if (call >> 16)		/* hack for backward compatibility */
 		return -EINVAL;
-	return compat_sys_ipc(call, first, second, third, ptr, third);
+	return compat_ksys_ipc(call, first, second, third, ptr, third);
 }
 #endif
 

arch/s390/kernel/entry.S

@@ -1512,7 +1512,7 @@ cleanup_critical:
 	.quad   .Lsie_skip - .Lsie_entry
 #endif
 	.section .rodata, "a"
-#define SYSCALL(esame,emu)	.long esame
+#define SYSCALL(esame,emu)	.long __s390x_ ## esame
 	.globl	sys_call_table
 sys_call_table:
 #include "asm/syscall_table.h"
@@ -1520,7 +1520,7 @@ sys_call_table:
 
 #ifdef CONFIG_COMPAT
 
-#define SYSCALL(esame,emu)	.long emu
+#define SYSCALL(esame,emu)	.long __s390_ ## emu
 	.globl	sys_call_table_emu
 sys_call_table_emu:
 #include "asm/syscall_table.h"

arch/s390/kernel/sys_s390.c

@@ -58,6 +58,7 @@ SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
 	return error;
 }
 
+#ifdef CONFIG_SYSVIPC
 /*
  * sys_ipc() is the de-multiplexer for the SysV IPC calls.
  */
@@ -74,19 +75,28 @@ SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,
 	 * Therefore we can call the generic variant by simply passing the
 	 * third parameter also as fifth parameter.
 	 */
-	return sys_ipc(call, first, second, third, ptr, third);
+	return ksys_ipc(call, first, second, third, ptr, third);
 }
+#endif /* CONFIG_SYSVIPC */
 
 SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
 {
-	unsigned int ret;
+	unsigned int ret = current->personality;
 
 	if (personality(current->personality) == PER_LINUX32 &&
 	    personality(personality) == PER_LINUX)
 		personality |= PER_LINUX32;
-	ret = sys_personality(personality);
+
+	if (personality != 0xffffffff)
+		set_personality(personality);
+
 	if (personality(ret) == PER_LINUX32)
 		ret &= ~PER_LINUX32;
 
 	return ret;
 }
+
+SYSCALL_DEFINE0(ni_syscall)
+{
+	return -ENOSYS;
+}

include/linux/syscalls.h

@@ -1185,6 +1185,10 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len,
 			      unsigned long prot, unsigned long flags,
 			      unsigned long fd, unsigned long pgoff);
 ssize_t ksys_readahead(int fd, loff_t offset, size_t count);
+int ksys_ipc(unsigned int call, int first, unsigned long second,
+	unsigned long third, void __user * ptr, long fifth);
+int compat_ksys_ipc(u32 call, int first, int second,
+	u32 third, u32 ptr, u32 fifth);
 
 /*
  * The following kernel syscall equivalents are just wrappers to fs-internal

ipc/syscall.c

@@ -17,8 +17,8 @@
 #include <linux/shm.h>
 #include <linux/uaccess.h>
 
-SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
-		unsigned long, third, void __user *, ptr, long, fifth)
+int ksys_ipc(unsigned int call, int first, unsigned long second,
+	unsigned long third, void __user * ptr, long fifth)
 {
 	int version, ret;
 
@@ -106,6 +106,12 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
 		return -ENOSYS;
 	}
 }
+
+SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
+		unsigned long, third, void __user *, ptr, long, fifth)
+{
+	return ksys_ipc(call, first, second, third, ptr, fifth);
+}
 #endif
 
 #ifdef CONFIG_COMPAT
@@ -121,8 +127,8 @@ struct compat_ipc_kludge {
 };
 
 #ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
-COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
-	u32, third, compat_uptr_t, ptr, u32, fifth)
+int compat_ksys_ipc(u32 call, int first, int second,
+	u32 third, compat_uptr_t ptr, u32 fifth)
 {
 	int version;
 	u32 pad;
@@ -195,5 +201,11 @@ COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
 
 	return -ENOSYS;
 }
+
+COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
+	u32, third, compat_uptr_t, ptr, u32, fifth)
+{
+	return compat_ksys_ipc(call, first, second, third, ptr, fifth);
+}
 #endif
 #endif

kernel/sys_ni.c

@@ -366,6 +366,7 @@ COND_SYSCALL(kexec_file_load);
 /* s390 */
 COND_SYSCALL(s390_pci_mmio_read);
 COND_SYSCALL(s390_pci_mmio_write);
+COND_SYSCALL(s390_ipc);
 COND_SYSCALL_COMPAT(s390_ipc);
 
 /* powerpc */