s390: use generic UID16 implementation

s390 has an almost identical copy of the code in kernel/uid16.c.

The problem here is that it requires calling the regular system calls,
which the generic implementation handles correctly, but the internal
interfaces are not declared in a global header for this.

The best way forward here seems to be to just use the generic code and
delete the s390 specific implementation.

I keep the changes to uapi/asm/posix_types.h inside of an #ifdef check
so user space does not observe any changes. As some of the system calls
pass pointers, we also need wrappers in compat_wrapper.c, which I add
for all calls with at least one argument. All those wrappers can be
removed in a later step.

Link: https://lore.kernel.org/lkml/20190116131527.2071570-4-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 0 insertions, 233 deletions

diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index a47f6d3c6d5b..f9d418d1b619 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/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>
@@ -58,238 +57,6 @@
 
 #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)