the-tree/kernel/sys.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  *  linux/kernel/sys.c
0004  *
0005  *  Copyright (C) 1991, 1992  Linus Torvalds
0006  */
0007
0008 #include <linux/export.h>
0009 #include <linux/mm.h>
0010 #include <linux/mm_inline.h>
0011 #include <linux/utsname.h>
0012 #include <linux/mman.h>
0013 #include <linux/reboot.h>
0014 #include <linux/prctl.h>
0015 #include <linux/highuid.h>
0016 #include <linux/fs.h>
0017 #include <linux/kmod.h>
0018 #include <linux/perf_event.h>
0019 #include <linux/resource.h>
0020 #include <linux/kernel.h>
0021 #include <linux/workqueue.h>
0022 #include <linux/capability.h>
0023 #include <linux/device.h>
0024 #include <linux/key.h>
0025 #include <linux/times.h>
0026 #include <linux/posix-timers.h>
0027 #include <linux/security.h>
0028 #include <linux/suspend.h>
0029 #include <linux/tty.h>
0030 #include <linux/signal.h>
0031 #include <linux/cn_proc.h>
0032 #include <linux/getcpu.h>
0033 #include <linux/task_io_accounting_ops.h>
0034 #include <linux/seccomp.h>
0035 #include <linux/cpu.h>
0036 #include <linux/personality.h>
0037 #include <linux/ptrace.h>
0038 #include <linux/fs_struct.h>
0039 #include <linux/file.h>
0040 #include <linux/mount.h>
0041 #include <linux/gfp.h>
0042 #include <linux/syscore_ops.h>
0043 #include <linux/version.h>
0044 #include <linux/ctype.h>
0045 #include <linux/syscall_user_dispatch.h>
0046
0047 #include <linux/compat.h>
0048 #include <linux/syscalls.h>
0049 #include <linux/kprobes.h>
0050 #include <linux/user_namespace.h>
0051 #include <linux/time_namespace.h>
0052 #include <linux/binfmts.h>
0053
0054 #include <linux/sched.h>
0055 #include <linux/sched/autogroup.h>
0056 #include <linux/sched/loadavg.h>
0057 #include <linux/sched/stat.h>
0058 #include <linux/sched/mm.h>
0059 #include <linux/sched/coredump.h>
0060 #include <linux/sched/task.h>
0061 #include <linux/sched/cputime.h>
0062 #include <linux/rcupdate.h>
0063 #include <linux/uidgid.h>
0064 #include <linux/cred.h>
0065
0066 #include <linux/nospec.h>
0067
0068 #include <linux/kmsg_dump.h>
0069 /* Move somewhere else to avoid recompiling? */
0070 #include <generated/utsrelease.h>
0071
0072 #include <linux/uaccess.h>
0073 #include <asm/io.h>
0074 #include <asm/unistd.h>
0075
0076 #include "uid16.h"
0077
0078 #ifndef SET_UNALIGN_CTL
0079 # define SET_UNALIGN_CTL(a, b)  (-EINVAL)
0080 #endif
0081 #ifndef GET_UNALIGN_CTL
0082 # define GET_UNALIGN_CTL(a, b)  (-EINVAL)
0083 #endif
0084 #ifndef SET_FPEMU_CTL
0085 # define SET_FPEMU_CTL(a, b)    (-EINVAL)
0086 #endif
0087 #ifndef GET_FPEMU_CTL
0088 # define GET_FPEMU_CTL(a, b)    (-EINVAL)
0089 #endif
0090 #ifndef SET_FPEXC_CTL
0091 # define SET_FPEXC_CTL(a, b)    (-EINVAL)
0092 #endif
0093 #ifndef GET_FPEXC_CTL
0094 # define GET_FPEXC_CTL(a, b)    (-EINVAL)
0095 #endif
0096 #ifndef GET_ENDIAN
0097 # define GET_ENDIAN(a, b)   (-EINVAL)
0098 #endif
0099 #ifndef SET_ENDIAN
0100 # define SET_ENDIAN(a, b)   (-EINVAL)
0101 #endif
0102 #ifndef GET_TSC_CTL
0103 # define GET_TSC_CTL(a)     (-EINVAL)
0104 #endif
0105 #ifndef SET_TSC_CTL
0106 # define SET_TSC_CTL(a)     (-EINVAL)
0107 #endif
0108 #ifndef GET_FP_MODE
0109 # define GET_FP_MODE(a)     (-EINVAL)
0110 #endif
0111 #ifndef SET_FP_MODE
0112 # define SET_FP_MODE(a,b)   (-EINVAL)
0113 #endif
0114 #ifndef SVE_SET_VL
0115 # define SVE_SET_VL(a)      (-EINVAL)
0116 #endif
0117 #ifndef SVE_GET_VL
0118 # define SVE_GET_VL()       (-EINVAL)
0119 #endif
0120 #ifndef SME_SET_VL
0121 # define SME_SET_VL(a)      (-EINVAL)
0122 #endif
0123 #ifndef SME_GET_VL
0124 # define SME_GET_VL()       (-EINVAL)
0125 #endif
0126 #ifndef PAC_RESET_KEYS
0127 # define PAC_RESET_KEYS(a, b)   (-EINVAL)
0128 #endif
0129 #ifndef PAC_SET_ENABLED_KEYS
0130 # define PAC_SET_ENABLED_KEYS(a, b, c)  (-EINVAL)
0131 #endif
0132 #ifndef PAC_GET_ENABLED_KEYS
0133 # define PAC_GET_ENABLED_KEYS(a)    (-EINVAL)
0134 #endif
0135 #ifndef SET_TAGGED_ADDR_CTRL
0136 # define SET_TAGGED_ADDR_CTRL(a)    (-EINVAL)
0137 #endif
0138 #ifndef GET_TAGGED_ADDR_CTRL
0139 # define GET_TAGGED_ADDR_CTRL()     (-EINVAL)
0140 #endif
0141
0142 /*
0143  * this is where the system-wide overflow UID and GID are defined, for
0144  * architectures that now have 32-bit UID/GID but didn't in the past
0145  */
0146
0147 int overflowuid = DEFAULT_OVERFLOWUID;
0148 int overflowgid = DEFAULT_OVERFLOWGID;
0149
0150 EXPORT_SYMBOL(overflowuid);
0151 EXPORT_SYMBOL(overflowgid);
0152
0153 /*
0154  * the same as above, but for filesystems which can only store a 16-bit
0155  * UID and GID. as such, this is needed on all architectures
0156  */
0157
0158 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
0159 int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
0160
0161 EXPORT_SYMBOL(fs_overflowuid);
0162 EXPORT_SYMBOL(fs_overflowgid);
0163
0164 /*
0165  * Returns true if current's euid is same as p's uid or euid,
0166  * or has CAP_SYS_NICE to p's user_ns.
0167  *
0168  * Called with rcu_read_lock, creds are safe
0169  */
0170 static bool set_one_prio_perm(struct task_struct *p)
0171 {
0172     const struct cred *cred = current_cred(), *pcred = __task_cred(p);
0173
0174     if (uid_eq(pcred->uid,  cred->euid) ||
0175         uid_eq(pcred->euid, cred->euid))
0176         return true;
0177     if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
0178         return true;
0179     return false;
0180 }
0181
0182 /*
0183  * set the priority of a task
0184  * - the caller must hold the RCU read lock
0185  */
0186 static int set_one_prio(struct task_struct *p, int niceval, int error)
0187 {
0188     int no_nice;
0189
0190     if (!set_one_prio_perm(p)) {
0191         error = -EPERM;
0192         goto out;
0193     }
0194     if (niceval < task_nice(p) && !can_nice(p, niceval)) {
0195         error = -EACCES;
0196         goto out;
0197     }
0198     no_nice = security_task_setnice(p, niceval);
0199     if (no_nice) {
0200         error = no_nice;
0201         goto out;
0202     }
0203     if (error == -ESRCH)
0204         error = 0;
0205     set_user_nice(p, niceval);
0206 out:
0207     return error;
0208 }
0209
0210 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
0211 {
0212     struct task_struct *g, *p;
0213     struct user_struct *user;
0214     const struct cred *cred = current_cred();
0215     int error = -EINVAL;
0216     struct pid *pgrp;
0217     kuid_t uid;
0218
0219     if (which > PRIO_USER || which < PRIO_PROCESS)
0220         goto out;
0221
0222     /* normalize: avoid signed division (rounding problems) */
0223     error = -ESRCH;
0224     if (niceval < MIN_NICE)
0225         niceval = MIN_NICE;
0226     if (niceval > MAX_NICE)
0227         niceval = MAX_NICE;
0228
0229     rcu_read_lock();
0230     switch (which) {
0231     case PRIO_PROCESS:
0232         if (who)
0233             p = find_task_by_vpid(who);
0234         else
0235             p = current;
0236         if (p)
0237             error = set_one_prio(p, niceval, error);
0238         break;
0239     case PRIO_PGRP:
0240         if (who)
0241             pgrp = find_vpid(who);
0242         else
0243             pgrp = task_pgrp(current);
0244         read_lock(&tasklist_lock);
0245         do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
0246             error = set_one_prio(p, niceval, error);
0247         } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
0248         read_unlock(&tasklist_lock);
0249         break;
0250     case PRIO_USER:
0251         uid = make_kuid(cred->user_ns, who);
0252         user = cred->user;
0253         if (!who)
0254             uid = cred->uid;
0255         else if (!uid_eq(uid, cred->uid)) {
0256             user = find_user(uid);
0257             if (!user)
0258                 goto out_unlock;    /* No processes for this user */
0259         }
0260         for_each_process_thread(g, p) {
0261             if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
0262                 error = set_one_prio(p, niceval, error);
0263         }
0264         if (!uid_eq(uid, cred->uid))
0265             free_uid(user);     /* For find_user() */
0266         break;
0267     }
0268 out_unlock:
0269     rcu_read_unlock();
0270 out:
0271     return error;
0272 }
0273
0274 /*
0275  * Ugh. To avoid negative return values, "getpriority()" will
0276  * not return the normal nice-value, but a negated value that
0277  * has been offset by 20 (ie it returns 40..1 instead of -20..19)
0278  * to stay compatible.
0279  */
0280 SYSCALL_DEFINE2(getpriority, int, which, int, who)
0281 {
0282     struct task_struct *g, *p;
0283     struct user_struct *user;
0284     const struct cred *cred = current_cred();
0285     long niceval, retval = -ESRCH;
0286     struct pid *pgrp;
0287     kuid_t uid;
0288
0289     if (which > PRIO_USER || which < PRIO_PROCESS)
0290         return -EINVAL;
0291
0292     rcu_read_lock();
0293     switch (which) {
0294     case PRIO_PROCESS:
0295         if (who)
0296             p = find_task_by_vpid(who);
0297         else
0298             p = current;
0299         if (p) {
0300             niceval = nice_to_rlimit(task_nice(p));
0301             if (niceval > retval)
0302                 retval = niceval;
0303         }
0304         break;
0305     case PRIO_PGRP:
0306         if (who)
0307             pgrp = find_vpid(who);
0308         else
0309             pgrp = task_pgrp(current);
0310         read_lock(&tasklist_lock);
0311         do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
0312             niceval = nice_to_rlimit(task_nice(p));
0313             if (niceval > retval)
0314                 retval = niceval;
0315         } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
0316         read_unlock(&tasklist_lock);
0317         break;
0318     case PRIO_USER:
0319         uid = make_kuid(cred->user_ns, who);
0320         user = cred->user;
0321         if (!who)
0322             uid = cred->uid;
0323         else if (!uid_eq(uid, cred->uid)) {
0324             user = find_user(uid);
0325             if (!user)
0326                 goto out_unlock;    /* No processes for this user */
0327         }
0328         for_each_process_thread(g, p) {
0329             if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
0330                 niceval = nice_to_rlimit(task_nice(p));
0331                 if (niceval > retval)
0332                     retval = niceval;
0333             }
0334         }
0335         if (!uid_eq(uid, cred->uid))
0336             free_uid(user);     /* for find_user() */
0337         break;
0338     }
0339 out_unlock:
0340     rcu_read_unlock();
0341
0342     return retval;
0343 }
0344
0345 /*
0346  * Unprivileged users may change the real gid to the effective gid
0347  * or vice versa.  (BSD-style)
0348  *
0349  * If you set the real gid at all, or set the effective gid to a value not
0350  * equal to the real gid, then the saved gid is set to the new effective gid.
0351  *
0352  * This makes it possible for a setgid program to completely drop its
0353  * privileges, which is often a useful assertion to make when you are doing
0354  * a security audit over a program.
0355  *
0356  * The general idea is that a program which uses just setregid() will be
0357  * 100% compatible with BSD.  A program which uses just setgid() will be
0358  * 100% compatible with POSIX with saved IDs.
0359  *
0360  * SMP: There are not races, the GIDs are checked only by filesystem
0361  *      operations (as far as semantic preservation is concerned).
0362  */
0363 #ifdef CONFIG_MULTIUSER
0364 long __sys_setregid(gid_t rgid, gid_t egid)
0365 {
0366     struct user_namespace *ns = current_user_ns();
0367     const struct cred *old;
0368     struct cred *new;
0369     int retval;
0370     kgid_t krgid, kegid;
0371
0372     krgid = make_kgid(ns, rgid);
0373     kegid = make_kgid(ns, egid);
0374
0375     if ((rgid != (gid_t) -1) && !gid_valid(krgid))
0376         return -EINVAL;
0377     if ((egid != (gid_t) -1) && !gid_valid(kegid))
0378         return -EINVAL;
0379
0380     new = prepare_creds();
0381     if (!new)
0382         return -ENOMEM;
0383     old = current_cred();
0384
0385     retval = -EPERM;
0386     if (rgid != (gid_t) -1) {
0387         if (gid_eq(old->gid, krgid) ||
0388             gid_eq(old->egid, krgid) ||
0389             ns_capable_setid(old->user_ns, CAP_SETGID))
0390             new->gid = krgid;
0391         else
0392             goto error;
0393     }
0394     if (egid != (gid_t) -1) {
0395         if (gid_eq(old->gid, kegid) ||
0396             gid_eq(old->egid, kegid) ||
0397             gid_eq(old->sgid, kegid) ||
0398             ns_capable_setid(old->user_ns, CAP_SETGID))
0399             new->egid = kegid;
0400         else
0401             goto error;
0402     }
0403
0404     if (rgid != (gid_t) -1 ||
0405         (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
0406         new->sgid = new->egid;
0407     new->fsgid = new->egid;
0408
0409     retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
0410     if (retval < 0)
0411         goto error;
0412
0413     return commit_creds(new);
0414
0415 error:
0416     abort_creds(new);
0417     return retval;
0418 }
0419
0420 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
0421 {
0422     return __sys_setregid(rgid, egid);
0423 }
0424
0425 /*
0426  * setgid() is implemented like SysV w/ SAVED_IDS
0427  *
0428  * SMP: Same implicit races as above.
0429  */
0430 long __sys_setgid(gid_t gid)
0431 {
0432     struct user_namespace *ns = current_user_ns();
0433     const struct cred *old;
0434     struct cred *new;
0435     int retval;
0436     kgid_t kgid;
0437
0438     kgid = make_kgid(ns, gid);
0439     if (!gid_valid(kgid))
0440         return -EINVAL;
0441
0442     new = prepare_creds();
0443     if (!new)
0444         return -ENOMEM;
0445     old = current_cred();
0446
0447     retval = -EPERM;
0448     if (ns_capable_setid(old->user_ns, CAP_SETGID))
0449         new->gid = new->egid = new->sgid = new->fsgid = kgid;
0450     else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
0451         new->egid = new->fsgid = kgid;
0452     else
0453         goto error;
0454
0455     retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
0456     if (retval < 0)
0457         goto error;
0458
0459     return commit_creds(new);
0460
0461 error:
0462     abort_creds(new);
0463     return retval;
0464 }
0465
0466 SYSCALL_DEFINE1(setgid, gid_t, gid)
0467 {
0468     return __sys_setgid(gid);
0469 }
0470
0471 /*
0472  * change the user struct in a credentials set to match the new UID
0473  */
0474 static int set_user(struct cred *new)
0475 {
0476     struct user_struct *new_user;
0477
0478     new_user = alloc_uid(new->uid);
0479     if (!new_user)
0480         return -EAGAIN;
0481
0482     free_uid(new->user);
0483     new->user = new_user;
0484     return 0;
0485 }
0486
0487 static void flag_nproc_exceeded(struct cred *new)
0488 {
0489     if (new->ucounts == current_ucounts())
0490         return;
0491
0492     /*
0493      * We don't fail in case of NPROC limit excess here because too many
0494      * poorly written programs don't check set*uid() return code, assuming
0495      * it never fails if called by root.  We may still enforce NPROC limit
0496      * for programs doing set*uid()+execve() by harmlessly deferring the
0497      * failure to the execve() stage.
0498      */
0499     if (is_ucounts_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
0500             new->user != INIT_USER)
0501         current->flags |= PF_NPROC_EXCEEDED;
0502     else
0503         current->flags &= ~PF_NPROC_EXCEEDED;
0504 }
0505
0506 /*
0507  * Unprivileged users may change the real uid to the effective uid
0508  * or vice versa.  (BSD-style)
0509  *
0510  * If you set the real uid at all, or set the effective uid to a value not
0511  * equal to the real uid, then the saved uid is set to the new effective uid.
0512  *
0513  * This makes it possible for a setuid program to completely drop its
0514  * privileges, which is often a useful assertion to make when you are doing
0515  * a security audit over a program.
0516  *
0517  * The general idea is that a program which uses just setreuid() will be
0518  * 100% compatible with BSD.  A program which uses just setuid() will be
0519  * 100% compatible with POSIX with saved IDs.
0520  */
0521 long __sys_setreuid(uid_t ruid, uid_t euid)
0522 {
0523     struct user_namespace *ns = current_user_ns();
0524     const struct cred *old;
0525     struct cred *new;
0526     int retval;
0527     kuid_t kruid, keuid;
0528
0529     kruid = make_kuid(ns, ruid);
0530     keuid = make_kuid(ns, euid);
0531
0532     if ((ruid != (uid_t) -1) && !uid_valid(kruid))
0533         return -EINVAL;
0534     if ((euid != (uid_t) -1) && !uid_valid(keuid))
0535         return -EINVAL;
0536
0537     new = prepare_creds();
0538     if (!new)
0539         return -ENOMEM;
0540     old = current_cred();
0541
0542     retval = -EPERM;
0543     if (ruid != (uid_t) -1) {
0544         new->uid = kruid;
0545         if (!uid_eq(old->uid, kruid) &&
0546             !uid_eq(old->euid, kruid) &&
0547             !ns_capable_setid(old->user_ns, CAP_SETUID))
0548             goto error;
0549     }
0550
0551     if (euid != (uid_t) -1) {
0552         new->euid = keuid;
0553         if (!uid_eq(old->uid, keuid) &&
0554             !uid_eq(old->euid, keuid) &&
0555             !uid_eq(old->suid, keuid) &&
0556             !ns_capable_setid(old->user_ns, CAP_SETUID))
0557             goto error;
0558     }
0559
0560     if (!uid_eq(new->uid, old->uid)) {
0561         retval = set_user(new);
0562         if (retval < 0)
0563             goto error;
0564     }
0565     if (ruid != (uid_t) -1 ||
0566         (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
0567         new->suid = new->euid;
0568     new->fsuid = new->euid;
0569
0570     retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
0571     if (retval < 0)
0572         goto error;
0573
0574     retval = set_cred_ucounts(new);
0575     if (retval < 0)
0576         goto error;
0577
0578     flag_nproc_exceeded(new);
0579     return commit_creds(new);
0580
0581 error:
0582     abort_creds(new);
0583     return retval;
0584 }
0585
0586 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
0587 {
0588     return __sys_setreuid(ruid, euid);
0589 }
0590
0591 /*
0592  * setuid() is implemented like SysV with SAVED_IDS
0593  *
0594  * Note that SAVED_ID's is deficient in that a setuid root program
0595  * like sendmail, for example, cannot set its uid to be a normal
0596  * user and then switch back, because if you're root, setuid() sets
0597  * the saved uid too.  If you don't like this, blame the bright people
0598  * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
0599  * will allow a root program to temporarily drop privileges and be able to
0600  * regain them by swapping the real and effective uid.
0601  */
0602 long __sys_setuid(uid_t uid)
0603 {
0604     struct user_namespace *ns = current_user_ns();
0605     const struct cred *old;
0606     struct cred *new;
0607     int retval;
0608     kuid_t kuid;
0609
0610     kuid = make_kuid(ns, uid);
0611     if (!uid_valid(kuid))
0612         return -EINVAL;
0613
0614     new = prepare_creds();
0615     if (!new)
0616         return -ENOMEM;
0617     old = current_cred();
0618
0619     retval = -EPERM;
0620     if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
0621         new->suid = new->uid = kuid;
0622         if (!uid_eq(kuid, old->uid)) {
0623             retval = set_user(new);
0624             if (retval < 0)
0625                 goto error;
0626         }
0627     } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
0628         goto error;
0629     }
0630
0631     new->fsuid = new->euid = kuid;
0632
0633     retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
0634     if (retval < 0)
0635         goto error;
0636
0637     retval = set_cred_ucounts(new);
0638     if (retval < 0)
0639         goto error;
0640
0641     flag_nproc_exceeded(new);
0642     return commit_creds(new);
0643
0644 error:
0645     abort_creds(new);
0646     return retval;
0647 }
0648
0649 SYSCALL_DEFINE1(setuid, uid_t, uid)
0650 {
0651     return __sys_setuid(uid);
0652 }
0653
0654
0655 /*
0656  * This function implements a generic ability to update ruid, euid,
0657  * and suid.  This allows you to implement the 4.4 compatible seteuid().
0658  */
0659 long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
0660 {
0661     struct user_namespace *ns = current_user_ns();
0662     const struct cred *old;
0663     struct cred *new;
0664     int retval;
0665     kuid_t kruid, keuid, ksuid;
0666
0667     kruid = make_kuid(ns, ruid);
0668     keuid = make_kuid(ns, euid);
0669     ksuid = make_kuid(ns, suid);
0670
0671     if ((ruid != (uid_t) -1) && !uid_valid(kruid))
0672         return -EINVAL;
0673
0674     if ((euid != (uid_t) -1) && !uid_valid(keuid))
0675         return -EINVAL;
0676
0677     if ((suid != (uid_t) -1) && !uid_valid(ksuid))
0678         return -EINVAL;
0679
0680     new = prepare_creds();
0681     if (!new)
0682         return -ENOMEM;
0683
0684     old = current_cred();
0685
0686     retval = -EPERM;
0687     if (!ns_capable_setid(old->user_ns, CAP_SETUID)) {
0688         if (ruid != (uid_t) -1        && !uid_eq(kruid, old->uid) &&
0689             !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
0690             goto error;
0691         if (euid != (uid_t) -1        && !uid_eq(keuid, old->uid) &&
0692             !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
0693             goto error;
0694         if (suid != (uid_t) -1        && !uid_eq(ksuid, old->uid) &&
0695             !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
0696             goto error;
0697     }
0698
0699     if (ruid != (uid_t) -1) {
0700         new->uid = kruid;
0701         if (!uid_eq(kruid, old->uid)) {
0702             retval = set_user(new);
0703             if (retval < 0)
0704                 goto error;
0705         }
0706     }
0707     if (euid != (uid_t) -1)
0708         new->euid = keuid;
0709     if (suid != (uid_t) -1)
0710         new->suid = ksuid;
0711     new->fsuid = new->euid;
0712
0713     retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
0714     if (retval < 0)
0715         goto error;
0716
0717     retval = set_cred_ucounts(new);
0718     if (retval < 0)
0719         goto error;
0720
0721     flag_nproc_exceeded(new);
0722     return commit_creds(new);
0723
0724 error:
0725     abort_creds(new);
0726     return retval;
0727 }
0728
0729 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
0730 {
0731     return __sys_setresuid(ruid, euid, suid);
0732 }
0733
0734 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
0735 {
0736     const struct cred *cred = current_cred();
0737     int retval;
0738     uid_t ruid, euid, suid;
0739
0740     ruid = from_kuid_munged(cred->user_ns, cred->uid);
0741     euid = from_kuid_munged(cred->user_ns, cred->euid);
0742     suid = from_kuid_munged(cred->user_ns, cred->suid);
0743
0744     retval = put_user(ruid, ruidp);
0745     if (!retval) {
0746         retval = put_user(euid, euidp);
0747         if (!retval)
0748             return put_user(suid, suidp);
0749     }
0750     return retval;
0751 }
0752
0753 /*
0754  * Same as above, but for rgid, egid, sgid.
0755  */
0756 long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
0757 {
0758     struct user_namespace *ns = current_user_ns();
0759     const struct cred *old;
0760     struct cred *new;
0761     int retval;
0762     kgid_t krgid, kegid, ksgid;
0763
0764     krgid = make_kgid(ns, rgid);
0765     kegid = make_kgid(ns, egid);
0766     ksgid = make_kgid(ns, sgid);
0767
0768     if ((rgid != (gid_t) -1) && !gid_valid(krgid))
0769         return -EINVAL;
0770     if ((egid != (gid_t) -1) && !gid_valid(kegid))
0771         return -EINVAL;
0772     if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
0773         return -EINVAL;
0774
0775     new = prepare_creds();
0776     if (!new)
0777         return -ENOMEM;
0778     old = current_cred();
0779
0780     retval = -EPERM;
0781     if (!ns_capable_setid(old->user_ns, CAP_SETGID)) {
0782         if (rgid != (gid_t) -1        && !gid_eq(krgid, old->gid) &&
0783             !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
0784             goto error;
0785         if (egid != (gid_t) -1        && !gid_eq(kegid, old->gid) &&
0786             !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
0787             goto error;
0788         if (sgid != (gid_t) -1        && !gid_eq(ksgid, old->gid) &&
0789             !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
0790             goto error;
0791     }
0792
0793     if (rgid != (gid_t) -1)
0794         new->gid = krgid;
0795     if (egid != (gid_t) -1)
0796         new->egid = kegid;
0797     if (sgid != (gid_t) -1)
0798         new->sgid = ksgid;
0799     new->fsgid = new->egid;
0800
0801     retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
0802     if (retval < 0)
0803         goto error;
0804
0805     return commit_creds(new);
0806
0807 error:
0808     abort_creds(new);
0809     return retval;
0810 }
0811
0812 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
0813 {
0814     return __sys_setresgid(rgid, egid, sgid);
0815 }
0816
0817 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
0818 {
0819     const struct cred *cred = current_cred();
0820     int retval;
0821     gid_t rgid, egid, sgid;
0822
0823     rgid = from_kgid_munged(cred->user_ns, cred->gid);
0824     egid = from_kgid_munged(cred->user_ns, cred->egid);
0825     sgid = from_kgid_munged(cred->user_ns, cred->sgid);
0826
0827     retval = put_user(rgid, rgidp);
0828     if (!retval) {
0829         retval = put_user(egid, egidp);
0830         if (!retval)
0831             retval = put_user(sgid, sgidp);
0832     }
0833
0834     return retval;
0835 }
0836
0837
0838 /*
0839  * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
0840  * is used for "access()" and for the NFS daemon (letting nfsd stay at
0841  * whatever uid it wants to). It normally shadows "euid", except when
0842  * explicitly set by setfsuid() or for access..
0843  */
0844 long __sys_setfsuid(uid_t uid)
0845 {
0846     const struct cred *old;
0847     struct cred *new;
0848     uid_t old_fsuid;
0849     kuid_t kuid;
0850
0851     old = current_cred();
0852     old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
0853
0854     kuid = make_kuid(old->user_ns, uid);
0855     if (!uid_valid(kuid))
0856         return old_fsuid;
0857
0858     new = prepare_creds();
0859     if (!new)
0860         return old_fsuid;
0861
0862     if (uid_eq(kuid, old->uid)  || uid_eq(kuid, old->euid)  ||
0863         uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
0864         ns_capable_setid(old->user_ns, CAP_SETUID)) {
0865         if (!uid_eq(kuid, old->fsuid)) {
0866             new->fsuid = kuid;
0867             if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
0868                 goto change_okay;
0869         }
0870     }
0871
0872     abort_creds(new);
0873     return old_fsuid;
0874
0875 change_okay:
0876     commit_creds(new);
0877     return old_fsuid;
0878 }
0879
0880 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
0881 {
0882     return __sys_setfsuid(uid);
0883 }
0884
0885 /*
0886  * Samma på svenska..
0887  */
0888 long __sys_setfsgid(gid_t gid)
0889 {
0890     const struct cred *old;
0891     struct cred *new;
0892     gid_t old_fsgid;
0893     kgid_t kgid;
0894
0895     old = current_cred();
0896     old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
0897
0898     kgid = make_kgid(old->user_ns, gid);
0899     if (!gid_valid(kgid))
0900         return old_fsgid;
0901
0902     new = prepare_creds();
0903     if (!new)
0904         return old_fsgid;
0905
0906     if (gid_eq(kgid, old->gid)  || gid_eq(kgid, old->egid)  ||
0907         gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
0908         ns_capable_setid(old->user_ns, CAP_SETGID)) {
0909         if (!gid_eq(kgid, old->fsgid)) {
0910             new->fsgid = kgid;
0911             if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
0912                 goto change_okay;
0913         }
0914     }
0915
0916     abort_creds(new);
0917     return old_fsgid;
0918
0919 change_okay:
0920     commit_creds(new);
0921     return old_fsgid;
0922 }
0923
0924 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
0925 {
0926     return __sys_setfsgid(gid);
0927 }
0928 #endif /* CONFIG_MULTIUSER */
0929
0930 /**
0931  * sys_getpid - return the thread group id of the current process
0932  *
0933  * Note, despite the name, this returns the tgid not the pid.  The tgid and
0934  * the pid are identical unless CLONE_THREAD was specified on clone() in
0935  * which case the tgid is the same in all threads of the same group.
0936  *
0937  * This is SMP safe as current->tgid does not change.
0938  */
0939 SYSCALL_DEFINE0(getpid)
0940 {
0941     return task_tgid_vnr(current);
0942 }
0943
0944 /* Thread ID - the internal kernel "pid" */
0945 SYSCALL_DEFINE0(gettid)
0946 {
0947     return task_pid_vnr(current);
0948 }
0949
0950 /*
0951  * Accessing ->real_parent is not SMP-safe, it could
0952  * change from under us. However, we can use a stale
0953  * value of ->real_parent under rcu_read_lock(), see
0954  * release_task()->call_rcu(delayed_put_task_struct).
0955  */
0956 SYSCALL_DEFINE0(getppid)
0957 {
0958     int pid;
0959
0960     rcu_read_lock();
0961     pid = task_tgid_vnr(rcu_dereference(current->real_parent));
0962     rcu_read_unlock();
0963
0964     return pid;
0965 }
0966
0967 SYSCALL_DEFINE0(getuid)
0968 {
0969     /* Only we change this so SMP safe */
0970     return from_kuid_munged(current_user_ns(), current_uid());
0971 }
0972
0973 SYSCALL_DEFINE0(geteuid)
0974 {
0975     /* Only we change this so SMP safe */
0976     return from_kuid_munged(current_user_ns(), current_euid());
0977 }
0978
0979 SYSCALL_DEFINE0(getgid)
0980 {
0981     /* Only we change this so SMP safe */
0982     return from_kgid_munged(current_user_ns(), current_gid());
0983 }
0984
0985 SYSCALL_DEFINE0(getegid)
0986 {
0987     /* Only we change this so SMP safe */
0988     return from_kgid_munged(current_user_ns(), current_egid());
0989 }
0990
0991 static void do_sys_times(struct tms *tms)
0992 {
0993     u64 tgutime, tgstime, cutime, cstime;
0994
0995     thread_group_cputime_adjusted(current, &tgutime, &tgstime);
0996     cutime = current->signal->cutime;
0997     cstime = current->signal->cstime;
0998     tms->tms_utime = nsec_to_clock_t(tgutime);
0999     tms->tms_stime = nsec_to_clock_t(tgstime);
1000     tms->tms_cutime = nsec_to_clock_t(cutime);
1001     tms->tms_cstime = nsec_to_clock_t(cstime);
1002 }
1003
1004 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1005 {
1006     if (tbuf) {
1007         struct tms tmp;
1008
1009         do_sys_times(&tmp);
1010         if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1011             return -EFAULT;
1012     }
1013     force_successful_syscall_return();
1014     return (long) jiffies_64_to_clock_t(get_jiffies_64());
1015 }
1016
1017 #ifdef CONFIG_COMPAT
1018 static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
1019 {
1020     return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
1021 }
1022
1023 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
1024 {
1025     if (tbuf) {
1026         struct tms tms;
1027         struct compat_tms tmp;
1028
1029         do_sys_times(&tms);
1030         /* Convert our struct tms to the compat version. */
1031         tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
1032         tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
1033         tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1034         tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1035         if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1036             return -EFAULT;
1037     }
1038     force_successful_syscall_return();
1039     return compat_jiffies_to_clock_t(jiffies);
1040 }
1041 #endif
1042
1043 /*
1044  * This needs some heavy checking ...
1045  * I just haven't the stomach for it. I also don't fully
1046  * understand sessions/pgrp etc. Let somebody who does explain it.
1047  *
1048  * OK, I think I have the protection semantics right.... this is really
1049  * only important on a multi-user system anyway, to make sure one user
1050  * can't send a signal to a process owned by another.  -TYT, 12/12/91
1051  *
1052  * !PF_FORKNOEXEC check to conform completely to POSIX.
1053  */
1054 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1055 {
1056     struct task_struct *p;
1057     struct task_struct *group_leader = current->group_leader;
1058     struct pid *pgrp;
1059     int err;
1060
1061     if (!pid)
1062         pid = task_pid_vnr(group_leader);
1063     if (!pgid)
1064         pgid = pid;
1065     if (pgid < 0)
1066         return -EINVAL;
1067     rcu_read_lock();
1068
1069     /* From this point forward we keep holding onto the tasklist lock
1070      * so that our parent does not change from under us. -DaveM
1071      */
1072     write_lock_irq(&tasklist_lock);
1073
1074     err = -ESRCH;
1075     p = find_task_by_vpid(pid);
1076     if (!p)
1077         goto out;
1078
1079     err = -EINVAL;
1080     if (!thread_group_leader(p))
1081         goto out;
1082
1083     if (same_thread_group(p->real_parent, group_leader)) {
1084         err = -EPERM;
1085         if (task_session(p) != task_session(group_leader))
1086             goto out;
1087         err = -EACCES;
1088         if (!(p->flags & PF_FORKNOEXEC))
1089             goto out;
1090     } else {
1091         err = -ESRCH;
1092         if (p != group_leader)
1093             goto out;
1094     }
1095
1096     err = -EPERM;
1097     if (p->signal->leader)
1098         goto out;
1099
1100     pgrp = task_pid(p);
1101     if (pgid != pid) {
1102         struct task_struct *g;
1103
1104         pgrp = find_vpid(pgid);
1105         g = pid_task(pgrp, PIDTYPE_PGID);
1106         if (!g || task_session(g) != task_session(group_leader))
1107             goto out;
1108     }
1109
1110     err = security_task_setpgid(p, pgid);
1111     if (err)
1112         goto out;
1113
1114     if (task_pgrp(p) != pgrp)
1115         change_pid(p, PIDTYPE_PGID, pgrp);
1116
1117     err = 0;
1118 out:
1119     /* All paths lead to here, thus we are safe. -DaveM */
1120     write_unlock_irq(&tasklist_lock);
1121     rcu_read_unlock();
1122     return err;
1123 }
1124
1125 static int do_getpgid(pid_t pid)
1126 {
1127     struct task_struct *p;
1128     struct pid *grp;
1129     int retval;
1130
1131     rcu_read_lock();
1132     if (!pid)
1133         grp = task_pgrp(current);
1134     else {
1135         retval = -ESRCH;
1136         p = find_task_by_vpid(pid);
1137         if (!p)
1138             goto out;
1139         grp = task_pgrp(p);
1140         if (!grp)
1141             goto out;
1142
1143         retval = security_task_getpgid(p);
1144         if (retval)
1145             goto out;
1146     }
1147     retval = pid_vnr(grp);
1148 out:
1149     rcu_read_unlock();
1150     return retval;
1151 }
1152
1153 SYSCALL_DEFINE1(getpgid, pid_t, pid)
1154 {
1155     return do_getpgid(pid);
1156 }
1157
1158 #ifdef __ARCH_WANT_SYS_GETPGRP
1159
1160 SYSCALL_DEFINE0(getpgrp)
1161 {
1162     return do_getpgid(0);
1163 }
1164
1165 #endif
1166
1167 SYSCALL_DEFINE1(getsid, pid_t, pid)
1168 {
1169     struct task_struct *p;
1170     struct pid *sid;
1171     int retval;
1172
1173     rcu_read_lock();
1174     if (!pid)
1175         sid = task_session(current);
1176     else {
1177         retval = -ESRCH;
1178         p = find_task_by_vpid(pid);
1179         if (!p)
1180             goto out;
1181         sid = task_session(p);
1182         if (!sid)
1183             goto out;
1184
1185         retval = security_task_getsid(p);
1186         if (retval)
1187             goto out;
1188     }
1189     retval = pid_vnr(sid);
1190 out:
1191     rcu_read_unlock();
1192     return retval;
1193 }
1194
1195 static void set_special_pids(struct pid *pid)
1196 {
1197     struct task_struct *curr = current->group_leader;
1198
1199     if (task_session(curr) != pid)
1200         change_pid(curr, PIDTYPE_SID, pid);
1201
1202     if (task_pgrp(curr) != pid)
1203         change_pid(curr, PIDTYPE_PGID, pid);
1204 }
1205
1206 int ksys_setsid(void)
1207 {
1208     struct task_struct *group_leader = current->group_leader;
1209     struct pid *sid = task_pid(group_leader);
1210     pid_t session = pid_vnr(sid);
1211     int err = -EPERM;
1212
1213     write_lock_irq(&tasklist_lock);
1214     /* Fail if I am already a session leader */
1215     if (group_leader->signal->leader)
1216         goto out;
1217
1218     /* Fail if a process group id already exists that equals the
1219      * proposed session id.
1220      */
1221     if (pid_task(sid, PIDTYPE_PGID))
1222         goto out;
1223
1224     group_leader->signal->leader = 1;
1225     set_special_pids(sid);
1226
1227     proc_clear_tty(group_leader);
1228
1229     err = session;
1230 out:
1231     write_unlock_irq(&tasklist_lock);
1232     if (err > 0) {
1233         proc_sid_connector(group_leader);
1234         sched_autogroup_create_attach(group_leader);
1235     }
1236     return err;
1237 }
1238
1239 SYSCALL_DEFINE0(setsid)
1240 {
1241     return ksys_setsid();
1242 }
1243
1244 DECLARE_RWSEM(uts_sem);
1245
1246 #ifdef COMPAT_UTS_MACHINE
1247 #define override_architecture(name) \
1248     (personality(current->personality) == PER_LINUX32 && \
1249      copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1250               sizeof(COMPAT_UTS_MACHINE)))
1251 #else
1252 #define override_architecture(name) 0
1253 #endif
1254
1255 /*
1256  * Work around broken programs that cannot handle "Linux 3.0".
1257  * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1258  * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1259  * 2.6.60.
1260  */
1261 static int override_release(char __user *release, size_t len)
1262 {
1263     int ret = 0;
1264
1265     if (current->personality & UNAME26) {
1266         const char *rest = UTS_RELEASE;
1267         char buf[65] = { 0 };
1268         int ndots = 0;
1269         unsigned v;
1270         size_t copy;
1271
1272         while (*rest) {
1273             if (*rest == '.' && ++ndots >= 3)
1274                 break;
1275             if (!isdigit(*rest) && *rest != '.')
1276                 break;
1277             rest++;
1278         }
1279         v = LINUX_VERSION_PATCHLEVEL + 60;
1280         copy = clamp_t(size_t, len, 1, sizeof(buf));
1281         copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1282         ret = copy_to_user(release, buf, copy + 1);
1283     }
1284     return ret;
1285 }
1286
1287 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1288 {
1289     struct new_utsname tmp;
1290
1291     down_read(&uts_sem);
1292     memcpy(&tmp, utsname(), sizeof(tmp));
1293     up_read(&uts_sem);
1294     if (copy_to_user(name, &tmp, sizeof(tmp)))
1295         return -EFAULT;
1296
1297     if (override_release(name->release, sizeof(name->release)))
1298         return -EFAULT;
1299     if (override_architecture(name))
1300         return -EFAULT;
1301     return 0;
1302 }
1303
1304 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1305 /*
1306  * Old cruft
1307  */
1308 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1309 {
1310     struct old_utsname tmp;
1311
1312     if (!name)
1313         return -EFAULT;
1314
1315     down_read(&uts_sem);
1316     memcpy(&tmp, utsname(), sizeof(tmp));
1317     up_read(&uts_sem);
1318     if (copy_to_user(name, &tmp, sizeof(tmp)))
1319         return -EFAULT;
1320
1321     if (override_release(name->release, sizeof(name->release)))
1322         return -EFAULT;
1323     if (override_architecture(name))
1324         return -EFAULT;
1325     return 0;
1326 }
1327
1328 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1329 {
1330     struct oldold_utsname tmp;
1331
1332     if (!name)
1333         return -EFAULT;
1334
1335     memset(&tmp, 0, sizeof(tmp));
1336
1337     down_read(&uts_sem);
1338     memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1339     memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1340     memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1341     memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1342     memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
1343     up_read(&uts_sem);
1344     if (copy_to_user(name, &tmp, sizeof(tmp)))
1345         return -EFAULT;
1346
1347     if (override_architecture(name))
1348         return -EFAULT;
1349     if (override_release(name->release, sizeof(name->release)))
1350         return -EFAULT;
1351     return 0;
1352 }
1353 #endif
1354
1355 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1356 {
1357     int errno;
1358     char tmp[__NEW_UTS_LEN];
1359
1360     if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1361         return -EPERM;
1362
1363     if (len < 0 || len > __NEW_UTS_LEN)
1364         return -EINVAL;
1365     errno = -EFAULT;
1366     if (!copy_from_user(tmp, name, len)) {
1367         struct new_utsname *u;
1368
1369         down_write(&uts_sem);
1370         u = utsname();
1371         memcpy(u->nodename, tmp, len);
1372         memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1373         errno = 0;
1374         uts_proc_notify(UTS_PROC_HOSTNAME);
1375         up_write(&uts_sem);
1376     }
1377     return errno;
1378 }
1379
1380 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1381
1382 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1383 {
1384     int i;
1385     struct new_utsname *u;
1386     char tmp[__NEW_UTS_LEN + 1];
1387
1388     if (len < 0)
1389         return -EINVAL;
1390     down_read(&uts_sem);
1391     u = utsname();
1392     i = 1 + strlen(u->nodename);
1393     if (i > len)
1394         i = len;
1395     memcpy(tmp, u->nodename, i);
1396     up_read(&uts_sem);
1397     if (copy_to_user(name, tmp, i))
1398         return -EFAULT;
1399     return 0;
1400 }
1401
1402 #endif
1403
1404 /*
1405  * Only setdomainname; getdomainname can be implemented by calling
1406  * uname()
1407  */
1408 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1409 {
1410     int errno;
1411     char tmp[__NEW_UTS_LEN];
1412
1413     if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1414         return -EPERM;
1415     if (len < 0 || len > __NEW_UTS_LEN)
1416         return -EINVAL;
1417
1418     errno = -EFAULT;
1419     if (!copy_from_user(tmp, name, len)) {
1420         struct new_utsname *u;
1421
1422         down_write(&uts_sem);
1423         u = utsname();
1424         memcpy(u->domainname, tmp, len);
1425         memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1426         errno = 0;
1427         uts_proc_notify(UTS_PROC_DOMAINNAME);
1428         up_write(&uts_sem);
1429     }
1430     return errno;
1431 }
1432
1433 /* make sure you are allowed to change @tsk limits before calling this */
1434 static int do_prlimit(struct task_struct *tsk, unsigned int resource,
1435               struct rlimit *new_rlim, struct rlimit *old_rlim)
1436 {
1437     struct rlimit *rlim;
1438     int retval = 0;
1439
1440     if (resource >= RLIM_NLIMITS)
1441         return -EINVAL;
1442     if (new_rlim) {
1443         if (new_rlim->rlim_cur > new_rlim->rlim_max)
1444             return -EINVAL;
1445         if (resource == RLIMIT_NOFILE &&
1446                 new_rlim->rlim_max > sysctl_nr_open)
1447             return -EPERM;
1448     }
1449
1450     /* Holding a refcount on tsk protects tsk->signal from disappearing. */
1451     rlim = tsk->signal->rlim + resource;
1452     task_lock(tsk->group_leader);
1453     if (new_rlim) {
1454         /*
1455          * Keep the capable check against init_user_ns until cgroups can
1456          * contain all limits.
1457          */
1458         if (new_rlim->rlim_max > rlim->rlim_max &&
1459                 !capable(CAP_SYS_RESOURCE))
1460             retval = -EPERM;
1461         if (!retval)
1462             retval = security_task_setrlimit(tsk, resource, new_rlim);
1463     }
1464     if (!retval) {
1465         if (old_rlim)
1466             *old_rlim = *rlim;
1467         if (new_rlim)
1468             *rlim = *new_rlim;
1469     }
1470     task_unlock(tsk->group_leader);
1471
1472     /*
1473      * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
1474      * infinite. In case of RLIM_INFINITY the posix CPU timer code
1475      * ignores the rlimit.
1476      */
1477     if (!retval && new_rlim && resource == RLIMIT_CPU &&
1478         new_rlim->rlim_cur != RLIM_INFINITY &&
1479         IS_ENABLED(CONFIG_POSIX_TIMERS)) {
1480         /*
1481          * update_rlimit_cpu can fail if the task is exiting, but there
1482          * may be other tasks in the thread group that are not exiting,
1483          * and they need their cpu timers adjusted.
1484          *
1485          * The group_leader is the last task to be released, so if we
1486          * cannot update_rlimit_cpu on it, then the entire process is
1487          * exiting and we do not need to update at all.
1488          */
1489         update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur);
1490     }
1491
1492     return retval;
1493 }
1494
1495 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1496 {
1497     struct rlimit value;
1498     int ret;
1499
1500     ret = do_prlimit(current, resource, NULL, &value);
1501     if (!ret)
1502         ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1503
1504     return ret;
1505 }
1506
1507 #ifdef CONFIG_COMPAT
1508
1509 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1510                struct compat_rlimit __user *, rlim)
1511 {
1512     struct rlimit r;
1513     struct compat_rlimit r32;
1514
1515     if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1516         return -EFAULT;
1517
1518     if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1519         r.rlim_cur = RLIM_INFINITY;
1520     else
1521         r.rlim_cur = r32.rlim_cur;
1522     if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1523         r.rlim_max = RLIM_INFINITY;
1524     else
1525         r.rlim_max = r32.rlim_max;
1526     return do_prlimit(current, resource, &r, NULL);
1527 }
1528
1529 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1530                struct compat_rlimit __user *, rlim)
1531 {
1532     struct rlimit r;
1533     int ret;
1534
1535     ret = do_prlimit(current, resource, NULL, &r);
1536     if (!ret) {
1537         struct compat_rlimit r32;
1538         if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1539             r32.rlim_cur = COMPAT_RLIM_INFINITY;
1540         else
1541             r32.rlim_cur = r.rlim_cur;
1542         if (r.rlim_max > COMPAT_RLIM_INFINITY)
1543             r32.rlim_max = COMPAT_RLIM_INFINITY;
1544         else
1545             r32.rlim_max = r.rlim_max;
1546
1547         if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1548             return -EFAULT;
1549     }
1550     return ret;
1551 }
1552
1553 #endif
1554
1555 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1556
1557 /*
1558  *  Back compatibility for getrlimit. Needed for some apps.
1559  */
1560 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1561         struct rlimit __user *, rlim)
1562 {
1563     struct rlimit x;
1564     if (resource >= RLIM_NLIMITS)
1565         return -EINVAL;
1566
1567     resource = array_index_nospec(resource, RLIM_NLIMITS);
1568     task_lock(current->group_leader);
1569     x = current->signal->rlim[resource];
1570     task_unlock(current->group_leader);
1571     if (x.rlim_cur > 0x7FFFFFFF)
1572         x.rlim_cur = 0x7FFFFFFF;
1573     if (x.rlim_max > 0x7FFFFFFF)
1574         x.rlim_max = 0x7FFFFFFF;
1575     return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1576 }
1577
1578 #ifdef CONFIG_COMPAT
1579 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1580                struct compat_rlimit __user *, rlim)
1581 {
1582     struct rlimit r;
1583
1584     if (resource >= RLIM_NLIMITS)
1585         return -EINVAL;
1586
1587     resource = array_index_nospec(resource, RLIM_NLIMITS);
1588     task_lock(current->group_leader);
1589     r = current->signal->rlim[resource];
1590     task_unlock(current->group_leader);
1591     if (r.rlim_cur > 0x7FFFFFFF)
1592         r.rlim_cur = 0x7FFFFFFF;
1593     if (r.rlim_max > 0x7FFFFFFF)
1594         r.rlim_max = 0x7FFFFFFF;
1595
1596     if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1597         put_user(r.rlim_max, &rlim->rlim_max))
1598         return -EFAULT;
1599     return 0;
1600 }
1601 #endif
1602
1603 #endif
1604
1605 static inline bool rlim64_is_infinity(__u64 rlim64)
1606 {
1607 #if BITS_PER_LONG < 64
1608     return rlim64 >= ULONG_MAX;
1609 #else
1610     return rlim64 == RLIM64_INFINITY;
1611 #endif
1612 }
1613
1614 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1615 {
1616     if (rlim->rlim_cur == RLIM_INFINITY)
1617         rlim64->rlim_cur = RLIM64_INFINITY;
1618     else
1619         rlim64->rlim_cur = rlim->rlim_cur;
1620     if (rlim->rlim_max == RLIM_INFINITY)
1621         rlim64->rlim_max = RLIM64_INFINITY;
1622     else
1623         rlim64->rlim_max = rlim->rlim_max;
1624 }
1625
1626 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1627 {
1628     if (rlim64_is_infinity(rlim64->rlim_cur))
1629         rlim->rlim_cur = RLIM_INFINITY;
1630     else
1631         rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1632     if (rlim64_is_infinity(rlim64->rlim_max))
1633         rlim->rlim_max = RLIM_INFINITY;
1634     else
1635         rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1636 }
1637
1638 /* rcu lock must be held */
1639 static int check_prlimit_permission(struct task_struct *task,
1640                     unsigned int flags)
1641 {
1642     const struct cred *cred = current_cred(), *tcred;
1643     bool id_match;
1644
1645     if (current == task)
1646         return 0;
1647
1648     tcred = __task_cred(task);
1649     id_match = (uid_eq(cred->uid, tcred->euid) &&
1650             uid_eq(cred->uid, tcred->suid) &&
1651             uid_eq(cred->uid, tcred->uid)  &&
1652             gid_eq(cred->gid, tcred->egid) &&
1653             gid_eq(cred->gid, tcred->sgid) &&
1654             gid_eq(cred->gid, tcred->gid));
1655     if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1656         return -EPERM;
1657
1658     return security_task_prlimit(cred, tcred, flags);
1659 }
1660
1661 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1662         const struct rlimit64 __user *, new_rlim,
1663         struct rlimit64 __user *, old_rlim)
1664 {
1665     struct rlimit64 old64, new64;
1666     struct rlimit old, new;
1667     struct task_struct *tsk;
1668     unsigned int checkflags = 0;
1669     int ret;
1670
1671     if (old_rlim)
1672         checkflags |= LSM_PRLIMIT_READ;
1673
1674     if (new_rlim) {
1675         if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1676             return -EFAULT;
1677         rlim64_to_rlim(&new64, &new);
1678         checkflags |= LSM_PRLIMIT_WRITE;
1679     }
1680
1681     rcu_read_lock();
1682     tsk = pid ? find_task_by_vpid(pid) : current;
1683     if (!tsk) {
1684         rcu_read_unlock();
1685         return -ESRCH;
1686     }
1687     ret = check_prlimit_permission(tsk, checkflags);
1688     if (ret) {
1689         rcu_read_unlock();
1690         return ret;
1691     }
1692     get_task_struct(tsk);
1693     rcu_read_unlock();
1694
1695     ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1696             old_rlim ? &old : NULL);
1697
1698     if (!ret && old_rlim) {
1699         rlim_to_rlim64(&old, &old64);
1700         if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1701             ret = -EFAULT;
1702     }
1703
1704     put_task_struct(tsk);
1705     return ret;
1706 }
1707
1708 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1709 {
1710     struct rlimit new_rlim;
1711
1712     if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1713         return -EFAULT;
1714     return do_prlimit(current, resource, &new_rlim, NULL);
1715 }
1716
1717 /*
1718  * It would make sense to put struct rusage in the task_struct,
1719  * except that would make the task_struct be *really big*.  After
1720  * task_struct gets moved into malloc'ed memory, it would
1721  * make sense to do this.  It will make moving the rest of the information
1722  * a lot simpler!  (Which we're not doing right now because we're not
1723  * measuring them yet).
1724  *
1725  * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1726  * races with threads incrementing their own counters.  But since word
1727  * reads are atomic, we either get new values or old values and we don't
1728  * care which for the sums.  We always take the siglock to protect reading
1729  * the c* fields from p->signal from races with exit.c updating those
1730  * fields when reaping, so a sample either gets all the additions of a
1731  * given child after it's reaped, or none so this sample is before reaping.
1732  *
1733  * Locking:
1734  * We need to take the siglock for CHILDEREN, SELF and BOTH
1735  * for  the cases current multithreaded, non-current single threaded
1736  * non-current multithreaded.  Thread traversal is now safe with
1737  * the siglock held.
1738  * Strictly speaking, we donot need to take the siglock if we are current and
1739  * single threaded,  as no one else can take our signal_struct away, no one
1740  * else can  reap the  children to update signal->c* counters, and no one else
1741  * can race with the signal-> fields. If we do not take any lock, the
1742  * signal-> fields could be read out of order while another thread was just
1743  * exiting. So we should  place a read memory barrier when we avoid the lock.
1744  * On the writer side,  write memory barrier is implied in  __exit_signal
1745  * as __exit_signal releases  the siglock spinlock after updating the signal->
1746  * fields. But we don't do this yet to keep things simple.
1747  *
1748  */
1749
1750 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1751 {
1752     r->ru_nvcsw += t->nvcsw;
1753     r->ru_nivcsw += t->nivcsw;
1754     r->ru_minflt += t->min_flt;
1755     r->ru_majflt += t->maj_flt;
1756     r->ru_inblock += task_io_get_inblock(t);
1757     r->ru_oublock += task_io_get_oublock(t);
1758 }
1759
1760 void getrusage(struct task_struct *p, int who, struct rusage *r)
1761 {
1762     struct task_struct *t;
1763     unsigned long flags;
1764     u64 tgutime, tgstime, utime, stime;
1765     unsigned long maxrss = 0;
1766
1767     memset((char *)r, 0, sizeof (*r));
1768     utime = stime = 0;
1769
1770     if (who == RUSAGE_THREAD) {
1771         task_cputime_adjusted(current, &utime, &stime);
1772         accumulate_thread_rusage(p, r);
1773         maxrss = p->signal->maxrss;
1774         goto out;
1775     }
1776
1777     if (!lock_task_sighand(p, &flags))
1778         return;
1779
1780     switch (who) {
1781     case RUSAGE_BOTH:
1782     case RUSAGE_CHILDREN:
1783         utime = p->signal->cutime;
1784         stime = p->signal->cstime;
1785         r->ru_nvcsw = p->signal->cnvcsw;
1786         r->ru_nivcsw = p->signal->cnivcsw;
1787         r->ru_minflt = p->signal->cmin_flt;
1788         r->ru_majflt = p->signal->cmaj_flt;
1789         r->ru_inblock = p->signal->cinblock;
1790         r->ru_oublock = p->signal->coublock;
1791         maxrss = p->signal->cmaxrss;
1792
1793         if (who == RUSAGE_CHILDREN)
1794             break;
1795         fallthrough;
1796
1797     case RUSAGE_SELF:
1798         thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1799         utime += tgutime;
1800         stime += tgstime;
1801         r->ru_nvcsw += p->signal->nvcsw;
1802         r->ru_nivcsw += p->signal->nivcsw;
1803         r->ru_minflt += p->signal->min_flt;
1804         r->ru_majflt += p->signal->maj_flt;
1805         r->ru_inblock += p->signal->inblock;
1806         r->ru_oublock += p->signal->oublock;
1807         if (maxrss < p->signal->maxrss)
1808             maxrss = p->signal->maxrss;
1809         t = p;
1810         do {
1811             accumulate_thread_rusage(t, r);
1812         } while_each_thread(p, t);
1813         break;
1814
1815     default:
1816         BUG();
1817     }
1818     unlock_task_sighand(p, &flags);
1819
1820 out:
1821     r->ru_utime = ns_to_kernel_old_timeval(utime);
1822     r->ru_stime = ns_to_kernel_old_timeval(stime);
1823
1824     if (who != RUSAGE_CHILDREN) {
1825         struct mm_struct *mm = get_task_mm(p);
1826
1827         if (mm) {
1828             setmax_mm_hiwater_rss(&maxrss, mm);
1829             mmput(mm);
1830         }
1831     }
1832     r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1833 }
1834
1835 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1836 {
1837     struct rusage r;
1838
1839     if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1840         who != RUSAGE_THREAD)
1841         return -EINVAL;
1842
1843     getrusage(current, who, &r);
1844     return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1845 }
1846
1847 #ifdef CONFIG_COMPAT
1848 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1849 {
1850     struct rusage r;
1851
1852     if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1853         who != RUSAGE_THREAD)
1854         return -EINVAL;
1855
1856     getrusage(current, who, &r);
1857     return put_compat_rusage(&r, ru);
1858 }
1859 #endif
1860
1861 SYSCALL_DEFINE1(umask, int, mask)
1862 {
1863     mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1864     return mask;
1865 }
1866
1867 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1868 {
1869     struct fd exe;
1870     struct inode *inode;
1871     int err;
1872
1873     exe = fdget(fd);
1874     if (!exe.file)
1875         return -EBADF;
1876
1877     inode = file_inode(exe.file);
1878
1879     /*
1880      * Because the original mm->exe_file points to executable file, make
1881      * sure that this one is executable as well, to avoid breaking an
1882      * overall picture.
1883      */
1884     err = -EACCES;
1885     if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
1886         goto exit;
1887
1888     err = file_permission(exe.file, MAY_EXEC);
1889     if (err)
1890         goto exit;
1891
1892     err = replace_mm_exe_file(mm, exe.file);
1893 exit:
1894     fdput(exe);
1895     return err;
1896 }
1897
1898 /*
1899  * Check arithmetic relations of passed addresses.
1900  *
1901  * WARNING: we don't require any capability here so be very careful
1902  * in what is allowed for modification from userspace.
1903  */
1904 static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
1905 {
1906     unsigned long mmap_max_addr = TASK_SIZE;
1907     int error = -EINVAL, i;
1908
1909     static const unsigned char offsets[] = {
1910         offsetof(struct prctl_mm_map, start_code),
1911         offsetof(struct prctl_mm_map, end_code),
1912         offsetof(struct prctl_mm_map, start_data),
1913         offsetof(struct prctl_mm_map, end_data),
1914         offsetof(struct prctl_mm_map, start_brk),
1915         offsetof(struct prctl_mm_map, brk),
1916         offsetof(struct prctl_mm_map, start_stack),
1917         offsetof(struct prctl_mm_map, arg_start),
1918         offsetof(struct prctl_mm_map, arg_end),
1919         offsetof(struct prctl_mm_map, env_start),
1920         offsetof(struct prctl_mm_map, env_end),
1921     };
1922
1923     /*
1924      * Make sure the members are not somewhere outside
1925      * of allowed address space.
1926      */
1927     for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1928         u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1929
1930         if ((unsigned long)val >= mmap_max_addr ||
1931             (unsigned long)val < mmap_min_addr)
1932             goto out;
1933     }
1934
1935     /*
1936      * Make sure the pairs are ordered.
1937      */
1938 #define __prctl_check_order(__m1, __op, __m2)               \
1939     ((unsigned long)prctl_map->__m1 __op                \
1940      (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1941     error  = __prctl_check_order(start_code, <, end_code);
1942     error |= __prctl_check_order(start_data,<=, end_data);
1943     error |= __prctl_check_order(start_brk, <=, brk);
1944     error |= __prctl_check_order(arg_start, <=, arg_end);
1945     error |= __prctl_check_order(env_start, <=, env_end);
1946     if (error)
1947         goto out;
1948 #undef __prctl_check_order
1949
1950     error = -EINVAL;
1951
1952     /*
1953      * Neither we should allow to override limits if they set.
1954      */
1955     if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1956                   prctl_map->start_brk, prctl_map->end_data,
1957                   prctl_map->start_data))
1958             goto out;
1959
1960     error = 0;
1961 out:
1962     return error;
1963 }
1964
1965 #ifdef CONFIG_CHECKPOINT_RESTORE
1966 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1967 {
1968     struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1969     unsigned long user_auxv[AT_VECTOR_SIZE];
1970     struct mm_struct *mm = current->mm;
1971     int error;
1972
1973     BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1974     BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1975
1976     if (opt == PR_SET_MM_MAP_SIZE)
1977         return put_user((unsigned int)sizeof(prctl_map),
1978                 (unsigned int __user *)addr);
1979
1980     if (data_size != sizeof(prctl_map))
1981         return -EINVAL;
1982
1983     if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1984         return -EFAULT;
1985
1986     error = validate_prctl_map_addr(&prctl_map);
1987     if (error)
1988         return error;
1989
1990     if (prctl_map.auxv_size) {
1991         /*
1992          * Someone is trying to cheat the auxv vector.
1993          */
1994         if (!prctl_map.auxv ||
1995                 prctl_map.auxv_size > sizeof(mm->saved_auxv))
1996             return -EINVAL;
1997
1998         memset(user_auxv, 0, sizeof(user_auxv));
1999         if (copy_from_user(user_auxv,
2000                    (const void __user *)prctl_map.auxv,
2001                    prctl_map.auxv_size))
2002             return -EFAULT;
2003
2004         /* Last entry must be AT_NULL as specification requires */
2005         user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2006         user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2007     }
2008
2009     if (prctl_map.exe_fd != (u32)-1) {
2010         /*
2011          * Check if the current user is checkpoint/restore capable.
2012          * At the time of this writing, it checks for CAP_SYS_ADMIN
2013          * or CAP_CHECKPOINT_RESTORE.
2014          * Note that a user with access to ptrace can masquerade an
2015          * arbitrary program as any executable, even setuid ones.
2016          * This may have implications in the tomoyo subsystem.
2017          */
2018         if (!checkpoint_restore_ns_capable(current_user_ns()))
2019             return -EPERM;
2020
2021         error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
2022         if (error)
2023             return error;
2024     }
2025
2026     /*
2027      * arg_lock protects concurrent updates but we still need mmap_lock for
2028      * read to exclude races with sys_brk.
2029      */
2030     mmap_read_lock(mm);
2031
2032     /*
2033      * We don't validate if these members are pointing to
2034      * real present VMAs because application may have correspond
2035      * VMAs already unmapped and kernel uses these members for statistics
2036      * output in procfs mostly, except
2037      *
2038      *  - @start_brk/@brk which are used in do_brk_flags but kernel lookups
2039      *    for VMAs when updating these members so anything wrong written
2040      *    here cause kernel to swear at userspace program but won't lead
2041      *    to any problem in kernel itself
2042      */
2043
2044     spin_lock(&mm->arg_lock);
2045     mm->start_code  = prctl_map.start_code;
2046     mm->end_code    = prctl_map.end_code;
2047     mm->start_data  = prctl_map.start_data;
2048     mm->end_data    = prctl_map.end_data;
2049     mm->start_brk   = prctl_map.start_brk;
2050     mm->brk     = prctl_map.brk;
2051     mm->start_stack = prctl_map.start_stack;
2052     mm->arg_start   = prctl_map.arg_start;
2053     mm->arg_end = prctl_map.arg_end;
2054     mm->env_start   = prctl_map.env_start;
2055     mm->env_end = prctl_map.env_end;
2056     spin_unlock(&mm->arg_lock);
2057
2058     /*
2059      * Note this update of @saved_auxv is lockless thus
2060      * if someone reads this member in procfs while we're
2061      * updating -- it may get partly updated results. It's
2062      * known and acceptable trade off: we leave it as is to
2063      * not introduce additional locks here making the kernel
2064      * more complex.
2065      */
2066     if (prctl_map.auxv_size)
2067         memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2068
2069     mmap_read_unlock(mm);
2070     return 0;
2071 }
2072 #endif /* CONFIG_CHECKPOINT_RESTORE */
2073
2074 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2075               unsigned long len)
2076 {
2077     /*
2078      * This doesn't move the auxiliary vector itself since it's pinned to
2079      * mm_struct, but it permits filling the vector with new values.  It's
2080      * up to the caller to provide sane values here, otherwise userspace
2081      * tools which use this vector might be unhappy.
2082      */
2083     unsigned long user_auxv[AT_VECTOR_SIZE] = {};
2084
2085     if (len > sizeof(user_auxv))
2086         return -EINVAL;
2087
2088     if (copy_from_user(user_auxv, (const void __user *)addr, len))
2089         return -EFAULT;
2090
2091     /* Make sure the last entry is always AT_NULL */
2092     user_auxv[AT_VECTOR_SIZE - 2] = 0;
2093     user_auxv[AT_VECTOR_SIZE - 1] = 0;
2094
2095     BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2096
2097     task_lock(current);
2098     memcpy(mm->saved_auxv, user_auxv, len);
2099     task_unlock(current);
2100
2101     return 0;
2102 }
2103
2104 static int prctl_set_mm(int opt, unsigned long addr,
2105             unsigned long arg4, unsigned long arg5)
2106 {
2107     struct mm_struct *mm = current->mm;
2108     struct prctl_mm_map prctl_map = {
2109         .auxv = NULL,
2110         .auxv_size = 0,
2111         .exe_fd = -1,
2112     };
2113     struct vm_area_struct *vma;
2114     int error;
2115
2116     if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2117                   opt != PR_SET_MM_MAP &&
2118                   opt != PR_SET_MM_MAP_SIZE)))
2119         return -EINVAL;
2120
2121 #ifdef CONFIG_CHECKPOINT_RESTORE
2122     if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2123         return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2124 #endif
2125
2126     if (!capable(CAP_SYS_RESOURCE))
2127         return -EPERM;
2128
2129     if (opt == PR_SET_MM_EXE_FILE)
2130         return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2131
2132     if (opt == PR_SET_MM_AUXV)
2133         return prctl_set_auxv(mm, addr, arg4);
2134
2135     if (addr >= TASK_SIZE || addr < mmap_min_addr)
2136         return -EINVAL;
2137
2138     error = -EINVAL;
2139
2140     /*
2141      * arg_lock protects concurrent updates of arg boundaries, we need
2142      * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
2143      * validation.
2144      */
2145     mmap_read_lock(mm);
2146     vma = find_vma(mm, addr);
2147
2148     spin_lock(&mm->arg_lock);
2149     prctl_map.start_code    = mm->start_code;
2150     prctl_map.end_code  = mm->end_code;
2151     prctl_map.start_data    = mm->start_data;
2152     prctl_map.end_data  = mm->end_data;
2153     prctl_map.start_brk = mm->start_brk;
2154     prctl_map.brk       = mm->brk;
2155     prctl_map.start_stack   = mm->start_stack;
2156     prctl_map.arg_start = mm->arg_start;
2157     prctl_map.arg_end   = mm->arg_end;
2158     prctl_map.env_start = mm->env_start;
2159     prctl_map.env_end   = mm->env_end;
2160
2161     switch (opt) {
2162     case PR_SET_MM_START_CODE:
2163         prctl_map.start_code = addr;
2164         break;
2165     case PR_SET_MM_END_CODE:
2166         prctl_map.end_code = addr;
2167         break;
2168     case PR_SET_MM_START_DATA:
2169         prctl_map.start_data = addr;
2170         break;
2171     case PR_SET_MM_END_DATA:
2172         prctl_map.end_data = addr;
2173         break;
2174     case PR_SET_MM_START_STACK:
2175         prctl_map.start_stack = addr;
2176         break;
2177     case PR_SET_MM_START_BRK:
2178         prctl_map.start_brk = addr;
2179         break;
2180     case PR_SET_MM_BRK:
2181         prctl_map.brk = addr;
2182         break;
2183     case PR_SET_MM_ARG_START:
2184         prctl_map.arg_start = addr;
2185         break;
2186     case PR_SET_MM_ARG_END:
2187         prctl_map.arg_end = addr;
2188         break;
2189     case PR_SET_MM_ENV_START:
2190         prctl_map.env_start = addr;
2191         break;
2192     case PR_SET_MM_ENV_END:
2193         prctl_map.env_end = addr;
2194         break;
2195     default:
2196         goto out;
2197     }
2198
2199     error = validate_prctl_map_addr(&prctl_map);
2200     if (error)
2201         goto out;
2202
2203     switch (opt) {
2204     /*
2205      * If command line arguments and environment
2206      * are placed somewhere else on stack, we can
2207      * set them up here, ARG_START/END to setup
2208      * command line arguments and ENV_START/END
2209      * for environment.
2210      */
2211     case PR_SET_MM_START_STACK:
2212     case PR_SET_MM_ARG_START:
2213     case PR_SET_MM_ARG_END:
2214     case PR_SET_MM_ENV_START:
2215     case PR_SET_MM_ENV_END:
2216         if (!vma) {
2217             error = -EFAULT;
2218             goto out;
2219         }
2220     }
2221
2222     mm->start_code  = prctl_map.start_code;
2223     mm->end_code    = prctl_map.end_code;
2224     mm->start_data  = prctl_map.start_data;
2225     mm->end_data    = prctl_map.end_data;
2226     mm->start_brk   = prctl_map.start_brk;
2227     mm->brk     = prctl_map.brk;
2228     mm->start_stack = prctl_map.start_stack;
2229     mm->arg_start   = prctl_map.arg_start;
2230     mm->arg_end = prctl_map.arg_end;
2231     mm->env_start   = prctl_map.env_start;
2232     mm->env_end = prctl_map.env_end;
2233
2234     error = 0;
2235 out:
2236     spin_unlock(&mm->arg_lock);
2237     mmap_read_unlock(mm);
2238     return error;
2239 }
2240
2241 #ifdef CONFIG_CHECKPOINT_RESTORE
2242 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2243 {
2244     return put_user(me->clear_child_tid, tid_addr);
2245 }
2246 #else
2247 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2248 {
2249     return -EINVAL;
2250 }
2251 #endif
2252
2253 static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2254 {
2255     /*
2256      * If task has has_child_subreaper - all its descendants
2257      * already have these flag too and new descendants will
2258      * inherit it on fork, skip them.
2259      *
2260      * If we've found child_reaper - skip descendants in
2261      * it's subtree as they will never get out pidns.
2262      */
2263     if (p->signal->has_child_subreaper ||
2264         is_child_reaper(task_pid(p)))
2265         return 0;
2266
2267     p->signal->has_child_subreaper = 1;
2268     return 1;
2269 }
2270
2271 int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
2272 {
2273     return -EINVAL;
2274 }
2275
2276 int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2277                     unsigned long ctrl)
2278 {
2279     return -EINVAL;
2280 }
2281
2282 #define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
2283
2284 #ifdef CONFIG_ANON_VMA_NAME
2285
2286 #define ANON_VMA_NAME_MAX_LEN       80
2287 #define ANON_VMA_NAME_INVALID_CHARS "\\`$[]"
2288
2289 static inline bool is_valid_name_char(char ch)
2290 {
2291     /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */
2292     return ch > 0x1f && ch < 0x7f &&
2293         !strchr(ANON_VMA_NAME_INVALID_CHARS, ch);
2294 }
2295
2296 static int prctl_set_vma(unsigned long opt, unsigned long addr,
2297              unsigned long size, unsigned long arg)
2298 {
2299     struct mm_struct *mm = current->mm;
2300     const char __user *uname;
2301     struct anon_vma_name *anon_name = NULL;
2302     int error;
2303
2304     switch (opt) {
2305     case PR_SET_VMA_ANON_NAME:
2306         uname = (const char __user *)arg;
2307         if (uname) {
2308             char *name, *pch;
2309
2310             name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN);
2311             if (IS_ERR(name))
2312                 return PTR_ERR(name);
2313
2314             for (pch = name; *pch != '\0'; pch++) {
2315                 if (!is_valid_name_char(*pch)) {
2316                     kfree(name);
2317                     return -EINVAL;
2318                 }
2319             }
2320             /* anon_vma has its own copy */
2321             anon_name = anon_vma_name_alloc(name);
2322             kfree(name);
2323             if (!anon_name)
2324                 return -ENOMEM;
2325
2326         }
2327
2328         mmap_write_lock(mm);
2329         error = madvise_set_anon_name(mm, addr, size, anon_name);
2330         mmap_write_unlock(mm);
2331         anon_vma_name_put(anon_name);
2332         break;
2333     default:
2334         error = -EINVAL;
2335     }
2336
2337     return error;
2338 }
2339
2340 #else /* CONFIG_ANON_VMA_NAME */
2341 static int prctl_set_vma(unsigned long opt, unsigned long start,
2342              unsigned long size, unsigned long arg)
2343 {
2344     return -EINVAL;
2345 }
2346 #endif /* CONFIG_ANON_VMA_NAME */
2347
2348 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2349         unsigned long, arg4, unsigned long, arg5)
2350 {
2351     struct task_struct *me = current;
2352     unsigned char comm[sizeof(me->comm)];
2353     long error;
2354
2355     error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2356     if (error != -ENOSYS)
2357         return error;
2358
2359     error = 0;
2360     switch (option) {
2361     case PR_SET_PDEATHSIG:
2362         if (!valid_signal(arg2)) {
2363             error = -EINVAL;
2364             break;
2365         }
2366         me->pdeath_signal = arg2;
2367         break;
2368     case PR_GET_PDEATHSIG:
2369         error = put_user(me->pdeath_signal, (int __user *)arg2);
2370         break;
2371     case PR_GET_DUMPABLE:
2372         error = get_dumpable(me->mm);
2373         break;
2374     case PR_SET_DUMPABLE:
2375         if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2376             error = -EINVAL;
2377             break;
2378         }
2379         set_dumpable(me->mm, arg2);
2380         break;
2381
2382     case PR_SET_UNALIGN:
2383         error = SET_UNALIGN_CTL(me, arg2);
2384         break;
2385     case PR_GET_UNALIGN:
2386         error = GET_UNALIGN_CTL(me, arg2);
2387         break;
2388     case PR_SET_FPEMU:
2389         error = SET_FPEMU_CTL(me, arg2);
2390         break;
2391     case PR_GET_FPEMU:
2392         error = GET_FPEMU_CTL(me, arg2);
2393         break;
2394     case PR_SET_FPEXC:
2395         error = SET_FPEXC_CTL(me, arg2);
2396         break;
2397     case PR_GET_FPEXC:
2398         error = GET_FPEXC_CTL(me, arg2);
2399         break;
2400     case PR_GET_TIMING:
2401         error = PR_TIMING_STATISTICAL;
2402         break;
2403     case PR_SET_TIMING:
2404         if (arg2 != PR_TIMING_STATISTICAL)
2405             error = -EINVAL;
2406         break;
2407     case PR_SET_NAME:
2408         comm[sizeof(me->comm) - 1] = 0;
2409         if (strncpy_from_user(comm, (char __user *)arg2,
2410                       sizeof(me->comm) - 1) < 0)
2411             return -EFAULT;
2412         set_task_comm(me, comm);
2413         proc_comm_connector(me);
2414         break;
2415     case PR_GET_NAME:
2416         get_task_comm(comm, me);
2417         if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2418             return -EFAULT;
2419         break;
2420     case PR_GET_ENDIAN:
2421         error = GET_ENDIAN(me, arg2);
2422         break;
2423     case PR_SET_ENDIAN:
2424         error = SET_ENDIAN(me, arg2);
2425         break;
2426     case PR_GET_SECCOMP:
2427         error = prctl_get_seccomp();
2428         break;
2429     case PR_SET_SECCOMP:
2430         error = prctl_set_seccomp(arg2, (char __user *)arg3);
2431         break;
2432     case PR_GET_TSC:
2433         error = GET_TSC_CTL(arg2);
2434         break;
2435     case PR_SET_TSC:
2436         error = SET_TSC_CTL(arg2);
2437         break;
2438     case PR_TASK_PERF_EVENTS_DISABLE:
2439         error = perf_event_task_disable();
2440         break;
2441     case PR_TASK_PERF_EVENTS_ENABLE:
2442         error = perf_event_task_enable();
2443         break;
2444     case PR_GET_TIMERSLACK:
2445         if (current->timer_slack_ns > ULONG_MAX)
2446             error = ULONG_MAX;
2447         else
2448             error = current->timer_slack_ns;
2449         break;
2450     case PR_SET_TIMERSLACK:
2451         if (arg2 <= 0)
2452             current->timer_slack_ns =
2453                     current->default_timer_slack_ns;
2454         else
2455             current->timer_slack_ns = arg2;
2456         break;
2457     case PR_MCE_KILL:
2458         if (arg4 | arg5)
2459             return -EINVAL;
2460         switch (arg2) {
2461         case PR_MCE_KILL_CLEAR:
2462             if (arg3 != 0)
2463                 return -EINVAL;
2464             current->flags &= ~PF_MCE_PROCESS;
2465             break;
2466         case PR_MCE_KILL_SET:
2467             current->flags |= PF_MCE_PROCESS;
2468             if (arg3 == PR_MCE_KILL_EARLY)
2469                 current->flags |= PF_MCE_EARLY;
2470             else if (arg3 == PR_MCE_KILL_LATE)
2471                 current->flags &= ~PF_MCE_EARLY;
2472             else if (arg3 == PR_MCE_KILL_DEFAULT)
2473                 current->flags &=
2474                         ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2475             else
2476                 return -EINVAL;
2477             break;
2478         default:
2479             return -EINVAL;
2480         }
2481         break;
2482     case PR_MCE_KILL_GET:
2483         if (arg2 | arg3 | arg4 | arg5)
2484             return -EINVAL;
2485         if (current->flags & PF_MCE_PROCESS)
2486             error = (current->flags & PF_MCE_EARLY) ?
2487                 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2488         else
2489             error = PR_MCE_KILL_DEFAULT;
2490         break;
2491     case PR_SET_MM:
2492         error = prctl_set_mm(arg2, arg3, arg4, arg5);
2493         break;
2494     case PR_GET_TID_ADDRESS:
2495         error = prctl_get_tid_address(me, (int __user * __user *)arg2);
2496         break;
2497     case PR_SET_CHILD_SUBREAPER:
2498         me->signal->is_child_subreaper = !!arg2;
2499         if (!arg2)
2500             break;
2501
2502         walk_process_tree(me, propagate_has_child_subreaper, NULL);
2503         break;
2504     case PR_GET_CHILD_SUBREAPER:
2505         error = put_user(me->signal->is_child_subreaper,
2506                  (int __user *)arg2);
2507         break;
2508     case PR_SET_NO_NEW_PRIVS:
2509         if (arg2 != 1 || arg3 || arg4 || arg5)
2510             return -EINVAL;
2511
2512         task_set_no_new_privs(current);
2513         break;
2514     case PR_GET_NO_NEW_PRIVS:
2515         if (arg2 || arg3 || arg4 || arg5)
2516             return -EINVAL;
2517         return task_no_new_privs(current) ? 1 : 0;
2518     case PR_GET_THP_DISABLE:
2519         if (arg2 || arg3 || arg4 || arg5)
2520             return -EINVAL;
2521         error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2522         break;
2523     case PR_SET_THP_DISABLE:
2524         if (arg3 || arg4 || arg5)
2525             return -EINVAL;
2526         if (mmap_write_lock_killable(me->mm))
2527             return -EINTR;
2528         if (arg2)
2529             set_bit(MMF_DISABLE_THP, &me->mm->flags);
2530         else
2531             clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2532         mmap_write_unlock(me->mm);
2533         break;
2534     case PR_MPX_ENABLE_MANAGEMENT:
2535     case PR_MPX_DISABLE_MANAGEMENT:
2536         /* No longer implemented: */
2537         return -EINVAL;
2538     case PR_SET_FP_MODE:
2539         error = SET_FP_MODE(me, arg2);
2540         break;
2541     case PR_GET_FP_MODE:
2542         error = GET_FP_MODE(me);
2543         break;
2544     case PR_SVE_SET_VL:
2545         error = SVE_SET_VL(arg2);
2546         break;
2547     case PR_SVE_GET_VL:
2548         error = SVE_GET_VL();
2549         break;
2550     case PR_SME_SET_VL:
2551         error = SME_SET_VL(arg2);
2552         break;
2553     case PR_SME_GET_VL:
2554         error = SME_GET_VL();
2555         break;
2556     case PR_GET_SPECULATION_CTRL:
2557         if (arg3 || arg4 || arg5)
2558             return -EINVAL;
2559         error = arch_prctl_spec_ctrl_get(me, arg2);
2560         break;
2561     case PR_SET_SPECULATION_CTRL:
2562         if (arg4 || arg5)
2563             return -EINVAL;
2564         error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
2565         break;
2566     case PR_PAC_RESET_KEYS:
2567         if (arg3 || arg4 || arg5)
2568             return -EINVAL;
2569         error = PAC_RESET_KEYS(me, arg2);
2570         break;
2571     case PR_PAC_SET_ENABLED_KEYS:
2572         if (arg4 || arg5)
2573             return -EINVAL;
2574         error = PAC_SET_ENABLED_KEYS(me, arg2, arg3);
2575         break;
2576     case PR_PAC_GET_ENABLED_KEYS:
2577         if (arg2 || arg3 || arg4 || arg5)
2578             return -EINVAL;
2579         error = PAC_GET_ENABLED_KEYS(me);
2580         break;
2581     case PR_SET_TAGGED_ADDR_CTRL:
2582         if (arg3 || arg4 || arg5)
2583             return -EINVAL;
2584         error = SET_TAGGED_ADDR_CTRL(arg2);
2585         break;
2586     case PR_GET_TAGGED_ADDR_CTRL:
2587         if (arg2 || arg3 || arg4 || arg5)
2588             return -EINVAL;
2589         error = GET_TAGGED_ADDR_CTRL();
2590         break;
2591     case PR_SET_IO_FLUSHER:
2592         if (!capable(CAP_SYS_RESOURCE))
2593             return -EPERM;
2594
2595         if (arg3 || arg4 || arg5)
2596             return -EINVAL;
2597
2598         if (arg2 == 1)
2599             current->flags |= PR_IO_FLUSHER;
2600         else if (!arg2)
2601             current->flags &= ~PR_IO_FLUSHER;
2602         else
2603             return -EINVAL;
2604         break;
2605     case PR_GET_IO_FLUSHER:
2606         if (!capable(CAP_SYS_RESOURCE))
2607             return -EPERM;
2608
2609         if (arg2 || arg3 || arg4 || arg5)
2610             return -EINVAL;
2611
2612         error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2613         break;
2614     case PR_SET_SYSCALL_USER_DISPATCH:
2615         error = set_syscall_user_dispatch(arg2, arg3, arg4,
2616                           (char __user *) arg5);
2617         break;
2618 #ifdef CONFIG_SCHED_CORE
2619     case PR_SCHED_CORE:
2620         error = sched_core_share_pid(arg2, arg3, arg4, arg5);
2621         break;
2622 #endif
2623     case PR_SET_VMA:
2624         error = prctl_set_vma(arg2, arg3, arg4, arg5);
2625         break;
2626     default:
2627         error = -EINVAL;
2628         break;
2629     }
2630     return error;
2631 }
2632
2633 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2634         struct getcpu_cache __user *, unused)
2635 {
2636     int err = 0;
2637     int cpu = raw_smp_processor_id();
2638
2639     if (cpup)
2640         err |= put_user(cpu, cpup);
2641     if (nodep)
2642         err |= put_user(cpu_to_node(cpu), nodep);
2643     return err ? -EFAULT : 0;
2644 }
2645
2646 /**
2647  * do_sysinfo - fill in sysinfo struct
2648  * @info: pointer to buffer to fill
2649  */
2650 static int do_sysinfo(struct sysinfo *info)
2651 {
2652     unsigned long mem_total, sav_total;
2653     unsigned int mem_unit, bitcount;
2654     struct timespec64 tp;
2655
2656     memset(info, 0, sizeof(struct sysinfo));
2657
2658     ktime_get_boottime_ts64(&tp);
2659     timens_add_boottime(&tp);
2660     info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2661
2662     get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2663
2664     info->procs = nr_threads;
2665
2666     si_meminfo(info);
2667     si_swapinfo(info);
2668
2669     /*
2670      * If the sum of all the available memory (i.e. ram + swap)
2671      * is less than can be stored in a 32 bit unsigned long then
2672      * we can be binary compatible with 2.2.x kernels.  If not,
2673      * well, in that case 2.2.x was broken anyways...
2674      *
2675      *  -Erik Andersen <andersee@debian.org>
2676      */
2677
2678     mem_total = info->totalram + info->totalswap;
2679     if (mem_total < info->totalram || mem_total < info->totalswap)
2680         goto out;
2681     bitcount = 0;
2682     mem_unit = info->mem_unit;
2683     while (mem_unit > 1) {
2684         bitcount++;
2685         mem_unit >>= 1;
2686         sav_total = mem_total;
2687         mem_total <<= 1;
2688         if (mem_total < sav_total)
2689             goto out;
2690     }
2691
2692     /*
2693      * If mem_total did not overflow, multiply all memory values by
2694      * info->mem_unit and set it to 1.  This leaves things compatible
2695      * with 2.2.x, and also retains compatibility with earlier 2.4.x
2696      * kernels...
2697      */
2698
2699     info->mem_unit = 1;
2700     info->totalram <<= bitcount;
2701     info->freeram <<= bitcount;
2702     info->sharedram <<= bitcount;
2703     info->bufferram <<= bitcount;
2704     info->totalswap <<= bitcount;
2705     info->freeswap <<= bitcount;
2706     info->totalhigh <<= bitcount;
2707     info->freehigh <<= bitcount;
2708
2709 out:
2710     return 0;
2711 }
2712
2713 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2714 {
2715     struct sysinfo val;
2716
2717     do_sysinfo(&val);
2718
2719     if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2720         return -EFAULT;
2721
2722     return 0;
2723 }
2724
2725 #ifdef CONFIG_COMPAT
2726 struct compat_sysinfo {
2727     s32 uptime;
2728     u32 loads[3];
2729     u32 totalram;
2730     u32 freeram;
2731     u32 sharedram;
2732     u32 bufferram;
2733     u32 totalswap;
2734     u32 freeswap;
2735     u16 procs;
2736     u16 pad;
2737     u32 totalhigh;
2738     u32 freehigh;
2739     u32 mem_unit;
2740     char _f[20-2*sizeof(u32)-sizeof(int)];
2741 };
2742
2743 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2744 {
2745     struct sysinfo s;
2746     struct compat_sysinfo s_32;
2747
2748     do_sysinfo(&s);
2749
2750     /* Check to see if any memory value is too large for 32-bit and scale
2751      *  down if needed
2752      */
2753     if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2754         int bitcount = 0;
2755
2756         while (s.mem_unit < PAGE_SIZE) {
2757             s.mem_unit <<= 1;
2758             bitcount++;
2759         }
2760
2761         s.totalram >>= bitcount;
2762         s.freeram >>= bitcount;
2763         s.sharedram >>= bitcount;
2764         s.bufferram >>= bitcount;
2765         s.totalswap >>= bitcount;
2766         s.freeswap >>= bitcount;
2767         s.totalhigh >>= bitcount;
2768         s.freehigh >>= bitcount;
2769     }
2770
2771     memset(&s_32, 0, sizeof(s_32));
2772     s_32.uptime = s.uptime;
2773     s_32.loads[0] = s.loads[0];
2774     s_32.loads[1] = s.loads[1];
2775     s_32.loads[2] = s.loads[2];
2776     s_32.totalram = s.totalram;
2777     s_32.freeram = s.freeram;
2778     s_32.sharedram = s.sharedram;
2779     s_32.bufferram = s.bufferram;
2780     s_32.totalswap = s.totalswap;
2781     s_32.freeswap = s.freeswap;
2782     s_32.procs = s.procs;
2783     s_32.totalhigh = s.totalhigh;
2784     s_32.freehigh = s.freehigh;
2785     s_32.mem_unit = s.mem_unit;
2786     if (copy_to_user(info, &s_32, sizeof(s_32)))
2787         return -EFAULT;
2788     return 0;
2789 }
2790 #endif /* CONFIG_COMPAT */