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Commit fef747ba authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Martin Schwidefsky
Browse files

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: default avatarArnd Bergmann <arnd@arndb.de>
Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 58fa4a41

arch/s390/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -379,6 +379,7 @@ 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/uapi/asm/posix_types.h

+6 −0
Original line number Diff line number Diff line
@@ -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/compat_linux.c

+0 −233
Original line number Diff line number Diff line
@@ -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)

arch/s390/kernel/compat_wrapper.c

+15 −0
Original line number Diff line number Diff line
@@ -184,3 +184,18 @@ COMPAT_SYSCALL_WRAP5(statx, int, dfd, const char __user *, path, unsigned, flags 
COMPAT_SYSCALL_WRAP4(s390_sthyi, unsigned long, code, void __user *, info, u64 __user *, rc, unsigned long, flags);

COMPAT_SYSCALL_WRAP5(kexec_file_load, int, kernel_fd, int, initrd_fd, unsigned long, cmdline_len, const char __user *, cmdline_ptr, unsigned long, flags)

COMPAT_SYSCALL_WRAP4(rseq, struct rseq __user *, rseq, u32, rseq_len, int, flags, u32, sig)

COMPAT_SYSCALL_WRAP3(chown16, const char __user *, filename, u16, user, u16, group);

COMPAT_SYSCALL_WRAP3(lchown16, const char __user *, filename, u16, user, u16, group);

COMPAT_SYSCALL_WRAP3(fchown16, unsigned int, fd, u16, user, u16, group);

COMPAT_SYSCALL_WRAP2(setregid16, u16, rgid, u16, egid);

COMPAT_SYSCALL_WRAP1(setgid16, u16, gid);

COMPAT_SYSCALL_WRAP2(setreuid16, u16, ruid, u16, euid);

COMPAT_SYSCALL_WRAP1(setuid16, u16, uid);

COMPAT_SYSCALL_WRAP3(setresuid16, u16, ruid, u16, euid, u16, suid);

COMPAT_SYSCALL_WRAP3(getresuid16, u16 __user *, ruidp, u16 __user *, euidp, u16 __user *, suidp);

COMPAT_SYSCALL_WRAP3(setresgid16, u16, rgid, u16, egid, u16, sgid);

COMPAT_SYSCALL_WRAP3(getresgid16, u16 __user *, rgidp, u16 __user *, egidp, u16 __user *, sgidp);

COMPAT_SYSCALL_WRAP1(setfsuid16, u16, uid);

COMPAT_SYSCALL_WRAP1(setfsgid16, u16, gid);

COMPAT_SYSCALL_WRAP2(getgroups16, int, gidsetsize, u16 __user *, grouplist);

COMPAT_SYSCALL_WRAP2(setgroups16, int, gidsetsize, u16 __user *, grouplist);

arch/s390/kernel/syscalls/syscall.tbl

+19 −19
Original line number Diff line number Diff line
@@ -23,13 +23,13 @@ 
13   32		time			-				compat_sys_time

14   common	mknod			sys_mknod			compat_sys_mknod

15   common	chmod			sys_chmod			compat_sys_chmod

16   32		lchown			-				compat_sys_s390_lchown16

16   32		lchown			-				compat_sys_lchown16

19   common	lseek			sys_lseek			compat_sys_lseek

20   common	getpid			sys_getpid			sys_getpid

21   common	mount			sys_mount			compat_sys_mount

22   common	umount			sys_oldumount			compat_sys_oldumount

23   32		setuid			-				compat_sys_s390_setuid16

24   32		getuid			-				compat_sys_s390_getuid16

23   32		setuid			-				compat_sys_setuid16

24   32		getuid			-				sys_getuid16

25   32		stime			-				compat_sys_stime

26   common	ptrace			sys_ptrace			compat_sys_ptrace

27   common	alarm			sys_alarm			sys_alarm
@@ -46,11 +46,11 @@ 
42   common	pipe			sys_pipe			compat_sys_pipe

43   common	times			sys_times			compat_sys_times

45   common	brk			sys_brk				compat_sys_brk

46   32		setgid			-				compat_sys_s390_setgid16

47   32		getgid			-				compat_sys_s390_getgid16

46   32		setgid			-				compat_sys_setgid16

47   32		getgid			-				sys_getgid16

48   common	signal			sys_signal			compat_sys_signal

49   32		geteuid			-				compat_sys_s390_geteuid16

50   32		getegid			-				compat_sys_s390_getegid16

49   32		geteuid			-				sys_geteuid16

50   32		getegid			-				sys_getegid16

51   common	acct			sys_acct			compat_sys_acct

52   common	umount2			sys_umount			compat_sys_umount

54   common	ioctl			sys_ioctl			compat_sys_ioctl
@@ -64,8 +64,8 @@ 
65   common	getpgrp			sys_getpgrp			sys_getpgrp

66   common	setsid			sys_setsid			sys_setsid

67   common	sigaction		sys_sigaction			compat_sys_sigaction

70   32		setreuid		-				compat_sys_s390_setreuid16

71   32		setregid		-				compat_sys_s390_setregid16

70   32		setreuid		-				compat_sys_setreuid16

71   32		setregid		-				compat_sys_setregid16

72   common	sigsuspend		sys_sigsuspend			compat_sys_sigsuspend

73   common	sigpending		sys_sigpending			compat_sys_sigpending

74   common	sethostname		sys_sethostname			compat_sys_sethostname
@@ -74,8 +74,8 @@ 
77   common	getrusage		sys_getrusage			compat_sys_getrusage

78   common	gettimeofday		sys_gettimeofday		compat_sys_gettimeofday

79   common	settimeofday		sys_settimeofday		compat_sys_settimeofday

80   32		getgroups		-				compat_sys_s390_getgroups16

81   32		setgroups		-				compat_sys_s390_setgroups16

80   32		getgroups		-				compat_sys_getgroups16

81   32		setgroups		-				compat_sys_setgroups16

83   common	symlink			sys_symlink			compat_sys_symlink

85   common	readlink		sys_readlink			compat_sys_readlink

86   common	uselib			sys_uselib			compat_sys_uselib
@@ -87,7 +87,7 @@ 
92   common	truncate		sys_truncate			compat_sys_truncate

93   common	ftruncate		sys_ftruncate			compat_sys_ftruncate

94   common	fchmod			sys_fchmod			sys_fchmod

95   32		fchown			-				compat_sys_s390_fchown16

95   32		fchown			-				compat_sys_fchown16

96   common	getpriority		sys_getpriority			sys_getpriority

97   common	setpriority		sys_setpriority			sys_setpriority

99   common	statfs			sys_statfs			compat_sys_statfs
@@ -126,8 +126,8 @@ 
135  common	sysfs			sys_sysfs			compat_sys_sysfs

136  common	personality		sys_s390_personality		sys_s390_personality

137  common	afs_syscall		-				-

138  32		setfsuid		-				compat_sys_s390_setfsuid16

139  32		setfsgid		-				compat_sys_s390_setfsgid16

138  32		setfsuid		-				compat_sys_setfsuid16

139  32		setfsgid		-				compat_sys_setfsgid16

140  32		_llseek			-				compat_sys_llseek

141  common	getdents		sys_getdents			compat_sys_getdents

142  32		_newselect		-				compat_sys_select
@@ -153,13 +153,13 @@ 
161  common	sched_rr_get_interval	sys_sched_rr_get_interval	compat_sys_sched_rr_get_interval

162  common	nanosleep		sys_nanosleep			compat_sys_nanosleep

163  common	mremap			sys_mremap			compat_sys_mremap

164  32		setresuid		-				compat_sys_s390_setresuid16

165  32		getresuid		-				compat_sys_s390_getresuid16

164  32		setresuid		-				compat_sys_setresuid16

165  32		getresuid		-				compat_sys_getresuid16

167  common	query_module		-				-

168  common	poll			sys_poll			compat_sys_poll

169  common	nfsservctl		-				-

170  32		setresgid		-				compat_sys_s390_setresgid16

171  32		getresgid		-				compat_sys_s390_getresgid16

170  32		setresgid		-				compat_sys_setresgid16

171  32		getresgid		-				compat_sys_getresgid16

172  common	prctl			sys_prctl			compat_sys_prctl

173  common	rt_sigreturn		sys_rt_sigreturn		compat_sys_rt_sigreturn

174  common	rt_sigaction		sys_rt_sigaction		compat_sys_rt_sigaction
@@ -170,7 +170,7 @@ 
179  common	rt_sigsuspend		sys_rt_sigsuspend		compat_sys_rt_sigsuspend

180  common	pread64			sys_pread64			compat_sys_s390_pread64

181  common	pwrite64		sys_pwrite64			compat_sys_s390_pwrite64

182  32		chown			-				compat_sys_s390_chown16

182  32		chown			-				compat_sys_chown16

183  common	getcwd			sys_getcwd			compat_sys_getcwd

184  common	capget			sys_capget			compat_sys_capget

185  common	capset			sys_capset			compat_sys_capset