![Dominik Brodowski](/assets/img/avatar_default.png)
Using this helper allows us to avoid the in-kernel calls to the sys_write() syscall. The ksys_ prefix denotes that this function is meant as a drop-in replacement for the syscall. In particular, it uses the same calling convention as sys_write(). In the near future, the do_mounts / initramfs callers of ksys_write() should be converted to use filp_open() and vfs_write() instead. This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-s390@vger.kernel.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
522 lines
13 KiB
C
522 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* S390 version
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* Copyright IBM Corp. 2000
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
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* Gerhard Tonn (ton@de.ibm.com)
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* Thomas Spatzier (tspat@de.ibm.com)
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*
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* Conversion between 31bit and 64bit native syscalls.
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*
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* Heavily inspired by the 32-bit Sparc compat code which is
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* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
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* Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
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*
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*/
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/file.h>
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#include <linux/signal.h>
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#include <linux/resource.h>
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#include <linux/times.h>
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#include <linux/smp.h>
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#include <linux/sem.h>
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#include <linux/msg.h>
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#include <linux/shm.h>
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#include <linux/uio.h>
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#include <linux/quota.h>
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#include <linux/poll.h>
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#include <linux/personality.h>
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#include <linux/stat.h>
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#include <linux/filter.h>
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#include <linux/highmem.h>
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#include <linux/highuid.h>
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#include <linux/mman.h>
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#include <linux/ipv6.h>
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#include <linux/in.h>
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#include <linux/icmpv6.h>
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#include <linux/syscalls.h>
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#include <linux/sysctl.h>
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#include <linux/binfmts.h>
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#include <linux/capability.h>
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#include <linux/compat.h>
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#include <linux/vfs.h>
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#include <linux/ptrace.h>
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#include <linux/fadvise.h>
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#include <linux/ipc.h>
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#include <linux/slab.h>
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#include <asm/types.h>
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#include <linux/uaccess.h>
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#include <net/scm.h>
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#include <net/sock.h>
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#include "compat_linux.h"
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/* For this source file, we want overflow handling. */
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#undef high2lowuid
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#undef high2lowgid
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#undef low2highuid
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#undef low2highgid
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#undef SET_UID16
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#undef SET_GID16
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#undef NEW_TO_OLD_UID
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#undef NEW_TO_OLD_GID
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#undef SET_OLDSTAT_UID
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#undef SET_OLDSTAT_GID
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#undef SET_STAT_UID
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#undef SET_STAT_GID
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#define high2lowuid(uid) ((uid) > 65535) ? (u16)overflowuid : (u16)(uid)
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#define high2lowgid(gid) ((gid) > 65535) ? (u16)overflowgid : (u16)(gid)
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#define low2highuid(uid) ((uid) == (u16)-1) ? (uid_t)-1 : (uid_t)(uid)
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#define low2highgid(gid) ((gid) == (u16)-1) ? (gid_t)-1 : (gid_t)(gid)
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#define SET_UID16(var, uid) var = high2lowuid(uid)
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#define SET_GID16(var, gid) var = high2lowgid(gid)
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#define NEW_TO_OLD_UID(uid) high2lowuid(uid)
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#define NEW_TO_OLD_GID(gid) high2lowgid(gid)
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#define SET_OLDSTAT_UID(stat, uid) (stat).st_uid = high2lowuid(uid)
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#define SET_OLDSTAT_GID(stat, gid) (stat).st_gid = high2lowgid(gid)
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#define SET_STAT_UID(stat, uid) (stat).st_uid = high2lowuid(uid)
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#define SET_STAT_GID(stat, gid) (stat).st_gid = high2lowgid(gid)
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COMPAT_SYSCALL_DEFINE3(s390_chown16, const char __user *, filename,
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u16, user, u16, group)
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{
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return sys_chown(filename, low2highuid(user), low2highgid(group));
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}
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COMPAT_SYSCALL_DEFINE3(s390_lchown16, const char __user *,
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filename, u16, user, u16, group)
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{
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return sys_lchown(filename, low2highuid(user), low2highgid(group));
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}
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COMPAT_SYSCALL_DEFINE3(s390_fchown16, unsigned int, fd, u16, user, u16, group)
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{
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return sys_fchown(fd, low2highuid(user), low2highgid(group));
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}
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COMPAT_SYSCALL_DEFINE2(s390_setregid16, u16, rgid, u16, egid)
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{
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return sys_setregid(low2highgid(rgid), low2highgid(egid));
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}
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COMPAT_SYSCALL_DEFINE1(s390_setgid16, u16, gid)
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{
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return sys_setgid(low2highgid(gid));
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}
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COMPAT_SYSCALL_DEFINE2(s390_setreuid16, u16, ruid, u16, euid)
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{
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return sys_setreuid(low2highuid(ruid), low2highuid(euid));
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}
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COMPAT_SYSCALL_DEFINE1(s390_setuid16, u16, uid)
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{
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return sys_setuid(low2highuid(uid));
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}
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COMPAT_SYSCALL_DEFINE3(s390_setresuid16, u16, ruid, u16, euid, u16, suid)
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{
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return sys_setresuid(low2highuid(ruid), low2highuid(euid),
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low2highuid(suid));
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}
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COMPAT_SYSCALL_DEFINE3(s390_getresuid16, u16 __user *, ruidp,
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u16 __user *, euidp, u16 __user *, suidp)
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{
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const struct cred *cred = current_cred();
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int retval;
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u16 ruid, euid, suid;
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ruid = high2lowuid(from_kuid_munged(cred->user_ns, cred->uid));
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euid = high2lowuid(from_kuid_munged(cred->user_ns, cred->euid));
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suid = high2lowuid(from_kuid_munged(cred->user_ns, cred->suid));
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if (!(retval = put_user(ruid, ruidp)) &&
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!(retval = put_user(euid, euidp)))
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retval = put_user(suid, suidp);
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return retval;
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}
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COMPAT_SYSCALL_DEFINE3(s390_setresgid16, u16, rgid, u16, egid, u16, sgid)
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{
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return sys_setresgid(low2highgid(rgid), low2highgid(egid),
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low2highgid(sgid));
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}
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COMPAT_SYSCALL_DEFINE3(s390_getresgid16, u16 __user *, rgidp,
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u16 __user *, egidp, u16 __user *, sgidp)
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{
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const struct cred *cred = current_cred();
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int retval;
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u16 rgid, egid, sgid;
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rgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->gid));
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egid = high2lowgid(from_kgid_munged(cred->user_ns, cred->egid));
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sgid = high2lowgid(from_kgid_munged(cred->user_ns, cred->sgid));
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if (!(retval = put_user(rgid, rgidp)) &&
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!(retval = put_user(egid, egidp)))
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retval = put_user(sgid, sgidp);
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return retval;
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}
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COMPAT_SYSCALL_DEFINE1(s390_setfsuid16, u16, uid)
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{
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return sys_setfsuid(low2highuid(uid));
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}
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COMPAT_SYSCALL_DEFINE1(s390_setfsgid16, u16, gid)
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{
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return sys_setfsgid(low2highgid(gid));
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}
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static int groups16_to_user(u16 __user *grouplist, struct group_info *group_info)
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{
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struct user_namespace *user_ns = current_user_ns();
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int i;
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u16 group;
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kgid_t kgid;
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for (i = 0; i < group_info->ngroups; i++) {
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kgid = group_info->gid[i];
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group = (u16)from_kgid_munged(user_ns, kgid);
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if (put_user(group, grouplist+i))
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return -EFAULT;
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}
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return 0;
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}
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static int groups16_from_user(struct group_info *group_info, u16 __user *grouplist)
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{
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struct user_namespace *user_ns = current_user_ns();
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int i;
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u16 group;
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kgid_t kgid;
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for (i = 0; i < group_info->ngroups; i++) {
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if (get_user(group, grouplist+i))
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return -EFAULT;
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kgid = make_kgid(user_ns, (gid_t)group);
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if (!gid_valid(kgid))
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return -EINVAL;
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group_info->gid[i] = kgid;
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}
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return 0;
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}
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COMPAT_SYSCALL_DEFINE2(s390_getgroups16, int, gidsetsize, u16 __user *, grouplist)
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{
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const struct cred *cred = current_cred();
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int i;
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if (gidsetsize < 0)
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return -EINVAL;
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get_group_info(cred->group_info);
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i = cred->group_info->ngroups;
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if (gidsetsize) {
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if (i > gidsetsize) {
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i = -EINVAL;
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goto out;
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}
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if (groups16_to_user(grouplist, cred->group_info)) {
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i = -EFAULT;
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goto out;
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}
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}
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out:
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put_group_info(cred->group_info);
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return i;
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}
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COMPAT_SYSCALL_DEFINE2(s390_setgroups16, int, gidsetsize, u16 __user *, grouplist)
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{
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struct group_info *group_info;
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int retval;
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if (!may_setgroups())
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return -EPERM;
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if ((unsigned)gidsetsize > NGROUPS_MAX)
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return -EINVAL;
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group_info = groups_alloc(gidsetsize);
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if (!group_info)
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return -ENOMEM;
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retval = groups16_from_user(group_info, grouplist);
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if (retval) {
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put_group_info(group_info);
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return retval;
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}
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groups_sort(group_info);
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retval = set_current_groups(group_info);
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put_group_info(group_info);
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return retval;
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}
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COMPAT_SYSCALL_DEFINE0(s390_getuid16)
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{
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return high2lowuid(from_kuid_munged(current_user_ns(), current_uid()));
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}
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COMPAT_SYSCALL_DEFINE0(s390_geteuid16)
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{
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return high2lowuid(from_kuid_munged(current_user_ns(), current_euid()));
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}
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COMPAT_SYSCALL_DEFINE0(s390_getgid16)
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{
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return high2lowgid(from_kgid_munged(current_user_ns(), current_gid()));
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}
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COMPAT_SYSCALL_DEFINE0(s390_getegid16)
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{
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return high2lowgid(from_kgid_munged(current_user_ns(), current_egid()));
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}
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#ifdef CONFIG_SYSVIPC
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COMPAT_SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, compat_ulong_t, second,
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compat_ulong_t, third, compat_uptr_t, ptr)
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{
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if (call >> 16) /* hack for backward compatibility */
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return -EINVAL;
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return compat_sys_ipc(call, first, second, third, ptr, third);
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}
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#endif
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COMPAT_SYSCALL_DEFINE3(s390_truncate64, const char __user *, path, u32, high, u32, low)
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{
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return sys_truncate(path, (unsigned long)high << 32 | low);
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}
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COMPAT_SYSCALL_DEFINE3(s390_ftruncate64, unsigned int, fd, u32, high, u32, low)
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{
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return sys_ftruncate(fd, (unsigned long)high << 32 | low);
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}
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COMPAT_SYSCALL_DEFINE5(s390_pread64, unsigned int, fd, char __user *, ubuf,
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compat_size_t, count, u32, high, u32, low)
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{
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if ((compat_ssize_t) count < 0)
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return -EINVAL;
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return sys_pread64(fd, ubuf, count, (unsigned long)high << 32 | low);
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}
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COMPAT_SYSCALL_DEFINE5(s390_pwrite64, unsigned int, fd, const char __user *, ubuf,
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compat_size_t, count, u32, high, u32, low)
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{
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if ((compat_ssize_t) count < 0)
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return -EINVAL;
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return sys_pwrite64(fd, ubuf, count, (unsigned long)high << 32 | low);
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}
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COMPAT_SYSCALL_DEFINE4(s390_readahead, int, fd, u32, high, u32, low, s32, count)
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{
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return sys_readahead(fd, (unsigned long)high << 32 | low, count);
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}
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struct stat64_emu31 {
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unsigned long long st_dev;
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unsigned int __pad1;
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#define STAT64_HAS_BROKEN_ST_INO 1
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u32 __st_ino;
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unsigned int st_mode;
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unsigned int st_nlink;
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u32 st_uid;
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u32 st_gid;
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unsigned long long st_rdev;
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unsigned int __pad3;
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long st_size;
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u32 st_blksize;
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unsigned char __pad4[4];
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u32 __pad5; /* future possible st_blocks high bits */
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u32 st_blocks; /* Number 512-byte blocks allocated. */
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u32 st_atime;
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u32 __pad6;
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u32 st_mtime;
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u32 __pad7;
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u32 st_ctime;
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u32 __pad8; /* will be high 32 bits of ctime someday */
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unsigned long st_ino;
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};
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static int cp_stat64(struct stat64_emu31 __user *ubuf, struct kstat *stat)
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{
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struct stat64_emu31 tmp;
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memset(&tmp, 0, sizeof(tmp));
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tmp.st_dev = huge_encode_dev(stat->dev);
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tmp.st_ino = stat->ino;
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tmp.__st_ino = (u32)stat->ino;
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tmp.st_mode = stat->mode;
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tmp.st_nlink = (unsigned int)stat->nlink;
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tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
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tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
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tmp.st_rdev = huge_encode_dev(stat->rdev);
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tmp.st_size = stat->size;
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tmp.st_blksize = (u32)stat->blksize;
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tmp.st_blocks = (u32)stat->blocks;
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tmp.st_atime = (u32)stat->atime.tv_sec;
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tmp.st_mtime = (u32)stat->mtime.tv_sec;
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tmp.st_ctime = (u32)stat->ctime.tv_sec;
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return copy_to_user(ubuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
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}
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COMPAT_SYSCALL_DEFINE2(s390_stat64, const char __user *, filename, struct stat64_emu31 __user *, statbuf)
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{
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struct kstat stat;
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int ret = vfs_stat(filename, &stat);
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if (!ret)
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ret = cp_stat64(statbuf, &stat);
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return ret;
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}
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COMPAT_SYSCALL_DEFINE2(s390_lstat64, const char __user *, filename, struct stat64_emu31 __user *, statbuf)
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{
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struct kstat stat;
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int ret = vfs_lstat(filename, &stat);
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if (!ret)
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ret = cp_stat64(statbuf, &stat);
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return ret;
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}
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COMPAT_SYSCALL_DEFINE2(s390_fstat64, unsigned int, fd, struct stat64_emu31 __user *, statbuf)
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{
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struct kstat stat;
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int ret = vfs_fstat(fd, &stat);
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if (!ret)
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ret = cp_stat64(statbuf, &stat);
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return ret;
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}
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COMPAT_SYSCALL_DEFINE4(s390_fstatat64, unsigned int, dfd, const char __user *, filename,
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struct stat64_emu31 __user *, statbuf, int, flag)
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{
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struct kstat stat;
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int error;
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error = vfs_fstatat(dfd, filename, &stat, flag);
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if (error)
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return error;
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return cp_stat64(statbuf, &stat);
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}
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/*
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* Linux/i386 didn't use to be able to handle more than
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* 4 system call parameters, so these system calls used a memory
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* block for parameter passing..
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*/
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struct mmap_arg_struct_emu31 {
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compat_ulong_t addr;
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compat_ulong_t len;
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compat_ulong_t prot;
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compat_ulong_t flags;
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compat_ulong_t fd;
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compat_ulong_t offset;
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};
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COMPAT_SYSCALL_DEFINE1(s390_old_mmap, struct mmap_arg_struct_emu31 __user *, arg)
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{
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struct mmap_arg_struct_emu31 a;
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if (copy_from_user(&a, arg, sizeof(a)))
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return -EFAULT;
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if (a.offset & ~PAGE_MASK)
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return -EINVAL;
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return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
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a.offset >> PAGE_SHIFT);
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}
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COMPAT_SYSCALL_DEFINE1(s390_mmap2, struct mmap_arg_struct_emu31 __user *, arg)
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{
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struct mmap_arg_struct_emu31 a;
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if (copy_from_user(&a, arg, sizeof(a)))
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return -EFAULT;
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return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
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}
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COMPAT_SYSCALL_DEFINE3(s390_read, unsigned int, fd, char __user *, buf, compat_size_t, count)
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{
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if ((compat_ssize_t) count < 0)
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return -EINVAL;
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return sys_read(fd, buf, count);
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}
|
|
|
|
COMPAT_SYSCALL_DEFINE3(s390_write, unsigned int, fd, const char __user *, buf, compat_size_t, count)
|
|
{
|
|
if ((compat_ssize_t) count < 0)
|
|
return -EINVAL;
|
|
|
|
return ksys_write(fd, buf, count);
|
|
}
|
|
|
|
/*
|
|
* 31 bit emulation wrapper functions for sys_fadvise64/fadvise64_64.
|
|
* These need to rewrite the advise values for POSIX_FADV_{DONTNEED,NOREUSE}
|
|
* because the 31 bit values differ from the 64 bit values.
|
|
*/
|
|
|
|
COMPAT_SYSCALL_DEFINE5(s390_fadvise64, int, fd, u32, high, u32, low, compat_size_t, len, int, advise)
|
|
{
|
|
if (advise == 4)
|
|
advise = POSIX_FADV_DONTNEED;
|
|
else if (advise == 5)
|
|
advise = POSIX_FADV_NOREUSE;
|
|
return sys_fadvise64(fd, (unsigned long)high << 32 | low, len, advise);
|
|
}
|
|
|
|
struct fadvise64_64_args {
|
|
int fd;
|
|
long long offset;
|
|
long long len;
|
|
int advice;
|
|
};
|
|
|
|
COMPAT_SYSCALL_DEFINE1(s390_fadvise64_64, struct fadvise64_64_args __user *, args)
|
|
{
|
|
struct fadvise64_64_args a;
|
|
|
|
if ( copy_from_user(&a, args, sizeof(a)) )
|
|
return -EFAULT;
|
|
if (a.advice == 4)
|
|
a.advice = POSIX_FADV_DONTNEED;
|
|
else if (a.advice == 5)
|
|
a.advice = POSIX_FADV_NOREUSE;
|
|
return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
|
|
}
|
|
|
|
COMPAT_SYSCALL_DEFINE6(s390_sync_file_range, int, fd, u32, offhigh, u32, offlow,
|
|
u32, nhigh, u32, nlow, unsigned int, flags)
|
|
{
|
|
return sys_sync_file_range(fd, ((loff_t)offhigh << 32) + offlow,
|
|
((u64)nhigh << 32) + nlow, flags);
|
|
}
|
|
|
|
COMPAT_SYSCALL_DEFINE6(s390_fallocate, int, fd, int, mode, u32, offhigh, u32, offlow,
|
|
u32, lenhigh, u32, lenlow)
|
|
{
|
|
return sys_fallocate(fd, mode, ((loff_t)offhigh << 32) + offlow,
|
|
((u64)lenhigh << 32) + lenlow);
|
|
}
|