![Rafael J. Wysocki](/assets/img/avatar_default.png)
Some subsystems need to carry out suspend/resume and shutdown operations with one CPU on-line and interrupts disabled. The only way to register such operations is to define a sysdev class and a sysdev specifically for this purpose which is cumbersome and inefficient. Moreover, the arguments taken by sysdev suspend, resume and shutdown callbacks are practically never necessary. For this reason, introduce a simpler interface allowing subsystems to register operations to be executed very late during system suspend and shutdown and very early during resume in the form of strcut syscore_ops objects. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
1819 lines
41 KiB
C
1819 lines
41 KiB
C
/*
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* linux/kernel/sys.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/utsname.h>
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#include <linux/mman.h>
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#include <linux/notifier.h>
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#include <linux/reboot.h>
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#include <linux/prctl.h>
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#include <linux/highuid.h>
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#include <linux/fs.h>
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#include <linux/perf_event.h>
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#include <linux/resource.h>
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#include <linux/kernel.h>
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#include <linux/kexec.h>
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#include <linux/workqueue.h>
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#include <linux/capability.h>
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#include <linux/device.h>
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#include <linux/key.h>
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#include <linux/times.h>
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#include <linux/posix-timers.h>
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#include <linux/security.h>
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#include <linux/dcookies.h>
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#include <linux/suspend.h>
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#include <linux/tty.h>
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#include <linux/signal.h>
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#include <linux/cn_proc.h>
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#include <linux/getcpu.h>
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#include <linux/task_io_accounting_ops.h>
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#include <linux/seccomp.h>
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#include <linux/cpu.h>
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#include <linux/personality.h>
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#include <linux/ptrace.h>
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#include <linux/fs_struct.h>
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#include <linux/gfp.h>
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#include <linux/syscore_ops.h>
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#include <linux/compat.h>
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#include <linux/syscalls.h>
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#include <linux/kprobes.h>
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#include <linux/user_namespace.h>
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#include <linux/kmsg_dump.h>
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#include <asm/uaccess.h>
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#include <asm/io.h>
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#include <asm/unistd.h>
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#ifndef SET_UNALIGN_CTL
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# define SET_UNALIGN_CTL(a,b) (-EINVAL)
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#endif
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#ifndef GET_UNALIGN_CTL
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# define GET_UNALIGN_CTL(a,b) (-EINVAL)
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#endif
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#ifndef SET_FPEMU_CTL
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# define SET_FPEMU_CTL(a,b) (-EINVAL)
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#endif
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#ifndef GET_FPEMU_CTL
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# define GET_FPEMU_CTL(a,b) (-EINVAL)
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#endif
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#ifndef SET_FPEXC_CTL
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# define SET_FPEXC_CTL(a,b) (-EINVAL)
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#endif
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#ifndef GET_FPEXC_CTL
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# define GET_FPEXC_CTL(a,b) (-EINVAL)
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#endif
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#ifndef GET_ENDIAN
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# define GET_ENDIAN(a,b) (-EINVAL)
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#endif
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#ifndef SET_ENDIAN
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# define SET_ENDIAN(a,b) (-EINVAL)
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#endif
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#ifndef GET_TSC_CTL
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# define GET_TSC_CTL(a) (-EINVAL)
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#endif
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#ifndef SET_TSC_CTL
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# define SET_TSC_CTL(a) (-EINVAL)
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#endif
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/*
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* this is where the system-wide overflow UID and GID are defined, for
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* architectures that now have 32-bit UID/GID but didn't in the past
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*/
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int overflowuid = DEFAULT_OVERFLOWUID;
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int overflowgid = DEFAULT_OVERFLOWGID;
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#ifdef CONFIG_UID16
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EXPORT_SYMBOL(overflowuid);
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EXPORT_SYMBOL(overflowgid);
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#endif
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/*
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* the same as above, but for filesystems which can only store a 16-bit
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* UID and GID. as such, this is needed on all architectures
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*/
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int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
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int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
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EXPORT_SYMBOL(fs_overflowuid);
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EXPORT_SYMBOL(fs_overflowgid);
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/*
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* this indicates whether you can reboot with ctrl-alt-del: the default is yes
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*/
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int C_A_D = 1;
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struct pid *cad_pid;
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EXPORT_SYMBOL(cad_pid);
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/*
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* If set, this is used for preparing the system to power off.
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*/
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void (*pm_power_off_prepare)(void);
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/*
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* set the priority of a task
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* - the caller must hold the RCU read lock
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*/
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static int set_one_prio(struct task_struct *p, int niceval, int error)
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{
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const struct cred *cred = current_cred(), *pcred = __task_cred(p);
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int no_nice;
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if (pcred->uid != cred->euid &&
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pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) {
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error = -EPERM;
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goto out;
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}
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if (niceval < task_nice(p) && !can_nice(p, niceval)) {
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error = -EACCES;
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goto out;
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}
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no_nice = security_task_setnice(p, niceval);
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if (no_nice) {
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error = no_nice;
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goto out;
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}
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if (error == -ESRCH)
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error = 0;
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set_user_nice(p, niceval);
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out:
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return error;
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}
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SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
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{
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struct task_struct *g, *p;
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struct user_struct *user;
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const struct cred *cred = current_cred();
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int error = -EINVAL;
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struct pid *pgrp;
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if (which > PRIO_USER || which < PRIO_PROCESS)
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goto out;
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/* normalize: avoid signed division (rounding problems) */
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error = -ESRCH;
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if (niceval < -20)
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niceval = -20;
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if (niceval > 19)
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niceval = 19;
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rcu_read_lock();
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read_lock(&tasklist_lock);
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switch (which) {
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case PRIO_PROCESS:
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if (who)
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p = find_task_by_vpid(who);
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else
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p = current;
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if (p)
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error = set_one_prio(p, niceval, error);
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break;
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case PRIO_PGRP:
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if (who)
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pgrp = find_vpid(who);
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else
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pgrp = task_pgrp(current);
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do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
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error = set_one_prio(p, niceval, error);
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} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
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break;
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case PRIO_USER:
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user = (struct user_struct *) cred->user;
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if (!who)
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who = cred->uid;
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else if ((who != cred->uid) &&
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!(user = find_user(who)))
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goto out_unlock; /* No processes for this user */
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do_each_thread(g, p) {
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if (__task_cred(p)->uid == who)
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error = set_one_prio(p, niceval, error);
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} while_each_thread(g, p);
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if (who != cred->uid)
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free_uid(user); /* For find_user() */
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break;
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}
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out_unlock:
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read_unlock(&tasklist_lock);
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rcu_read_unlock();
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out:
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return error;
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}
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/*
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* Ugh. To avoid negative return values, "getpriority()" will
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* not return the normal nice-value, but a negated value that
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* has been offset by 20 (ie it returns 40..1 instead of -20..19)
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* to stay compatible.
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*/
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SYSCALL_DEFINE2(getpriority, int, which, int, who)
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{
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struct task_struct *g, *p;
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struct user_struct *user;
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const struct cred *cred = current_cred();
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long niceval, retval = -ESRCH;
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struct pid *pgrp;
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if (which > PRIO_USER || which < PRIO_PROCESS)
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return -EINVAL;
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rcu_read_lock();
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read_lock(&tasklist_lock);
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switch (which) {
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case PRIO_PROCESS:
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if (who)
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p = find_task_by_vpid(who);
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else
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p = current;
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if (p) {
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niceval = 20 - task_nice(p);
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if (niceval > retval)
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retval = niceval;
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}
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break;
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case PRIO_PGRP:
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if (who)
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pgrp = find_vpid(who);
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else
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pgrp = task_pgrp(current);
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do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
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niceval = 20 - task_nice(p);
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if (niceval > retval)
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retval = niceval;
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} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
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break;
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case PRIO_USER:
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user = (struct user_struct *) cred->user;
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if (!who)
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who = cred->uid;
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else if ((who != cred->uid) &&
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!(user = find_user(who)))
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goto out_unlock; /* No processes for this user */
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do_each_thread(g, p) {
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if (__task_cred(p)->uid == who) {
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niceval = 20 - task_nice(p);
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if (niceval > retval)
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retval = niceval;
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}
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} while_each_thread(g, p);
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if (who != cred->uid)
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free_uid(user); /* for find_user() */
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break;
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}
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out_unlock:
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read_unlock(&tasklist_lock);
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rcu_read_unlock();
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return retval;
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}
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/**
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* emergency_restart - reboot the system
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*
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* Without shutting down any hardware or taking any locks
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* reboot the system. This is called when we know we are in
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* trouble so this is our best effort to reboot. This is
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* safe to call in interrupt context.
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*/
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void emergency_restart(void)
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{
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kmsg_dump(KMSG_DUMP_EMERG);
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machine_emergency_restart();
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}
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EXPORT_SYMBOL_GPL(emergency_restart);
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void kernel_restart_prepare(char *cmd)
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{
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blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
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system_state = SYSTEM_RESTART;
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device_shutdown();
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sysdev_shutdown();
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syscore_shutdown();
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}
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/**
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* kernel_restart - reboot the system
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* @cmd: pointer to buffer containing command to execute for restart
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* or %NULL
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*
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* Shutdown everything and perform a clean reboot.
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* This is not safe to call in interrupt context.
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*/
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void kernel_restart(char *cmd)
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{
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kernel_restart_prepare(cmd);
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if (!cmd)
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printk(KERN_EMERG "Restarting system.\n");
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else
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printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
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kmsg_dump(KMSG_DUMP_RESTART);
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machine_restart(cmd);
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}
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EXPORT_SYMBOL_GPL(kernel_restart);
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static void kernel_shutdown_prepare(enum system_states state)
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{
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blocking_notifier_call_chain(&reboot_notifier_list,
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(state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
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system_state = state;
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device_shutdown();
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}
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/**
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* kernel_halt - halt the system
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*
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* Shutdown everything and perform a clean system halt.
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*/
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void kernel_halt(void)
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{
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kernel_shutdown_prepare(SYSTEM_HALT);
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sysdev_shutdown();
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syscore_shutdown();
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printk(KERN_EMERG "System halted.\n");
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kmsg_dump(KMSG_DUMP_HALT);
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machine_halt();
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}
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EXPORT_SYMBOL_GPL(kernel_halt);
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/**
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* kernel_power_off - power_off the system
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*
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* Shutdown everything and perform a clean system power_off.
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*/
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void kernel_power_off(void)
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{
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kernel_shutdown_prepare(SYSTEM_POWER_OFF);
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if (pm_power_off_prepare)
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pm_power_off_prepare();
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disable_nonboot_cpus();
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sysdev_shutdown();
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syscore_shutdown();
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printk(KERN_EMERG "Power down.\n");
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kmsg_dump(KMSG_DUMP_POWEROFF);
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machine_power_off();
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}
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EXPORT_SYMBOL_GPL(kernel_power_off);
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static DEFINE_MUTEX(reboot_mutex);
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/*
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* Reboot system call: for obvious reasons only root may call it,
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* and even root needs to set up some magic numbers in the registers
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* so that some mistake won't make this reboot the whole machine.
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* You can also set the meaning of the ctrl-alt-del-key here.
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*
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* reboot doesn't sync: do that yourself before calling this.
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*/
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SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
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void __user *, arg)
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{
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char buffer[256];
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int ret = 0;
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/* We only trust the superuser with rebooting the system. */
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if (!capable(CAP_SYS_BOOT))
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return -EPERM;
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/* For safety, we require "magic" arguments. */
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if (magic1 != LINUX_REBOOT_MAGIC1 ||
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(magic2 != LINUX_REBOOT_MAGIC2 &&
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magic2 != LINUX_REBOOT_MAGIC2A &&
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magic2 != LINUX_REBOOT_MAGIC2B &&
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magic2 != LINUX_REBOOT_MAGIC2C))
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return -EINVAL;
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/* Instead of trying to make the power_off code look like
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* halt when pm_power_off is not set do it the easy way.
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*/
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if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
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cmd = LINUX_REBOOT_CMD_HALT;
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mutex_lock(&reboot_mutex);
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switch (cmd) {
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case LINUX_REBOOT_CMD_RESTART:
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kernel_restart(NULL);
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break;
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case LINUX_REBOOT_CMD_CAD_ON:
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C_A_D = 1;
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break;
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case LINUX_REBOOT_CMD_CAD_OFF:
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C_A_D = 0;
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break;
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|
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case LINUX_REBOOT_CMD_HALT:
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kernel_halt();
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do_exit(0);
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panic("cannot halt");
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|
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case LINUX_REBOOT_CMD_POWER_OFF:
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kernel_power_off();
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do_exit(0);
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break;
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|
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case LINUX_REBOOT_CMD_RESTART2:
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if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
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ret = -EFAULT;
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break;
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}
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buffer[sizeof(buffer) - 1] = '\0';
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|
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kernel_restart(buffer);
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break;
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|
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#ifdef CONFIG_KEXEC
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case LINUX_REBOOT_CMD_KEXEC:
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ret = kernel_kexec();
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break;
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#endif
|
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|
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#ifdef CONFIG_HIBERNATION
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case LINUX_REBOOT_CMD_SW_SUSPEND:
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ret = hibernate();
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break;
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#endif
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|
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default:
|
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ret = -EINVAL;
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break;
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}
|
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mutex_unlock(&reboot_mutex);
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return ret;
|
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}
|
|
|
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static void deferred_cad(struct work_struct *dummy)
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{
|
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kernel_restart(NULL);
|
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}
|
|
|
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/*
|
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* This function gets called by ctrl-alt-del - ie the keyboard interrupt.
|
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* As it's called within an interrupt, it may NOT sync: the only choice
|
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* is whether to reboot at once, or just ignore the ctrl-alt-del.
|
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*/
|
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void ctrl_alt_del(void)
|
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{
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static DECLARE_WORK(cad_work, deferred_cad);
|
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|
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if (C_A_D)
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schedule_work(&cad_work);
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else
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kill_cad_pid(SIGINT, 1);
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}
|
|
|
|
/*
|
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* Unprivileged users may change the real gid to the effective gid
|
|
* or vice versa. (BSD-style)
|
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*
|
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* If you set the real gid at all, or set the effective gid to a value not
|
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* equal to the real gid, then the saved gid is set to the new effective gid.
|
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*
|
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* This makes it possible for a setgid program to completely drop its
|
|
* privileges, which is often a useful assertion to make when you are doing
|
|
* a security audit over a program.
|
|
*
|
|
* The general idea is that a program which uses just setregid() will be
|
|
* 100% compatible with BSD. A program which uses just setgid() will be
|
|
* 100% compatible with POSIX with saved IDs.
|
|
*
|
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* SMP: There are not races, the GIDs are checked only by filesystem
|
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* operations (as far as semantic preservation is concerned).
|
|
*/
|
|
SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
|
|
{
|
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const struct cred *old;
|
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struct cred *new;
|
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int retval;
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|
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new = prepare_creds();
|
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if (!new)
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return -ENOMEM;
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old = current_cred();
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|
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retval = -EPERM;
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if (rgid != (gid_t) -1) {
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if (old->gid == rgid ||
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old->egid == rgid ||
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capable(CAP_SETGID))
|
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new->gid = rgid;
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else
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goto error;
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}
|
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if (egid != (gid_t) -1) {
|
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if (old->gid == egid ||
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old->egid == egid ||
|
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old->sgid == egid ||
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capable(CAP_SETGID))
|
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new->egid = egid;
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else
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goto error;
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}
|
|
|
|
if (rgid != (gid_t) -1 ||
|
|
(egid != (gid_t) -1 && egid != old->gid))
|
|
new->sgid = new->egid;
|
|
new->fsgid = new->egid;
|
|
|
|
return commit_creds(new);
|
|
|
|
error:
|
|
abort_creds(new);
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* setgid() is implemented like SysV w/ SAVED_IDS
|
|
*
|
|
* SMP: Same implicit races as above.
|
|
*/
|
|
SYSCALL_DEFINE1(setgid, gid_t, gid)
|
|
{
|
|
const struct cred *old;
|
|
struct cred *new;
|
|
int retval;
|
|
|
|
new = prepare_creds();
|
|
if (!new)
|
|
return -ENOMEM;
|
|
old = current_cred();
|
|
|
|
retval = -EPERM;
|
|
if (capable(CAP_SETGID))
|
|
new->gid = new->egid = new->sgid = new->fsgid = gid;
|
|
else if (gid == old->gid || gid == old->sgid)
|
|
new->egid = new->fsgid = gid;
|
|
else
|
|
goto error;
|
|
|
|
return commit_creds(new);
|
|
|
|
error:
|
|
abort_creds(new);
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* change the user struct in a credentials set to match the new UID
|
|
*/
|
|
static int set_user(struct cred *new)
|
|
{
|
|
struct user_struct *new_user;
|
|
|
|
new_user = alloc_uid(current_user_ns(), new->uid);
|
|
if (!new_user)
|
|
return -EAGAIN;
|
|
|
|
if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
|
|
new_user != INIT_USER) {
|
|
free_uid(new_user);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
free_uid(new->user);
|
|
new->user = new_user;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Unprivileged users may change the real uid to the effective uid
|
|
* or vice versa. (BSD-style)
|
|
*
|
|
* If you set the real uid at all, or set the effective uid to a value not
|
|
* equal to the real uid, then the saved uid is set to the new effective uid.
|
|
*
|
|
* This makes it possible for a setuid program to completely drop its
|
|
* privileges, which is often a useful assertion to make when you are doing
|
|
* a security audit over a program.
|
|
*
|
|
* The general idea is that a program which uses just setreuid() will be
|
|
* 100% compatible with BSD. A program which uses just setuid() will be
|
|
* 100% compatible with POSIX with saved IDs.
|
|
*/
|
|
SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
|
|
{
|
|
const struct cred *old;
|
|
struct cred *new;
|
|
int retval;
|
|
|
|
new = prepare_creds();
|
|
if (!new)
|
|
return -ENOMEM;
|
|
old = current_cred();
|
|
|
|
retval = -EPERM;
|
|
if (ruid != (uid_t) -1) {
|
|
new->uid = ruid;
|
|
if (old->uid != ruid &&
|
|
old->euid != ruid &&
|
|
!capable(CAP_SETUID))
|
|
goto error;
|
|
}
|
|
|
|
if (euid != (uid_t) -1) {
|
|
new->euid = euid;
|
|
if (old->uid != euid &&
|
|
old->euid != euid &&
|
|
old->suid != euid &&
|
|
!capable(CAP_SETUID))
|
|
goto error;
|
|
}
|
|
|
|
if (new->uid != old->uid) {
|
|
retval = set_user(new);
|
|
if (retval < 0)
|
|
goto error;
|
|
}
|
|
if (ruid != (uid_t) -1 ||
|
|
(euid != (uid_t) -1 && euid != old->uid))
|
|
new->suid = new->euid;
|
|
new->fsuid = new->euid;
|
|
|
|
retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
|
|
if (retval < 0)
|
|
goto error;
|
|
|
|
return commit_creds(new);
|
|
|
|
error:
|
|
abort_creds(new);
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* setuid() is implemented like SysV with SAVED_IDS
|
|
*
|
|
* Note that SAVED_ID's is deficient in that a setuid root program
|
|
* like sendmail, for example, cannot set its uid to be a normal
|
|
* user and then switch back, because if you're root, setuid() sets
|
|
* the saved uid too. If you don't like this, blame the bright people
|
|
* in the POSIX committee and/or USG. Note that the BSD-style setreuid()
|
|
* will allow a root program to temporarily drop privileges and be able to
|
|
* regain them by swapping the real and effective uid.
|
|
*/
|
|
SYSCALL_DEFINE1(setuid, uid_t, uid)
|
|
{
|
|
const struct cred *old;
|
|
struct cred *new;
|
|
int retval;
|
|
|
|
new = prepare_creds();
|
|
if (!new)
|
|
return -ENOMEM;
|
|
old = current_cred();
|
|
|
|
retval = -EPERM;
|
|
if (capable(CAP_SETUID)) {
|
|
new->suid = new->uid = uid;
|
|
if (uid != old->uid) {
|
|
retval = set_user(new);
|
|
if (retval < 0)
|
|
goto error;
|
|
}
|
|
} else if (uid != old->uid && uid != new->suid) {
|
|
goto error;
|
|
}
|
|
|
|
new->fsuid = new->euid = uid;
|
|
|
|
retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
|
|
if (retval < 0)
|
|
goto error;
|
|
|
|
return commit_creds(new);
|
|
|
|
error:
|
|
abort_creds(new);
|
|
return retval;
|
|
}
|
|
|
|
|
|
/*
|
|
* This function implements a generic ability to update ruid, euid,
|
|
* and suid. This allows you to implement the 4.4 compatible seteuid().
|
|
*/
|
|
SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
|
|
{
|
|
const struct cred *old;
|
|
struct cred *new;
|
|
int retval;
|
|
|
|
new = prepare_creds();
|
|
if (!new)
|
|
return -ENOMEM;
|
|
|
|
old = current_cred();
|
|
|
|
retval = -EPERM;
|
|
if (!capable(CAP_SETUID)) {
|
|
if (ruid != (uid_t) -1 && ruid != old->uid &&
|
|
ruid != old->euid && ruid != old->suid)
|
|
goto error;
|
|
if (euid != (uid_t) -1 && euid != old->uid &&
|
|
euid != old->euid && euid != old->suid)
|
|
goto error;
|
|
if (suid != (uid_t) -1 && suid != old->uid &&
|
|
suid != old->euid && suid != old->suid)
|
|
goto error;
|
|
}
|
|
|
|
if (ruid != (uid_t) -1) {
|
|
new->uid = ruid;
|
|
if (ruid != old->uid) {
|
|
retval = set_user(new);
|
|
if (retval < 0)
|
|
goto error;
|
|
}
|
|
}
|
|
if (euid != (uid_t) -1)
|
|
new->euid = euid;
|
|
if (suid != (uid_t) -1)
|
|
new->suid = suid;
|
|
new->fsuid = new->euid;
|
|
|
|
retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
|
|
if (retval < 0)
|
|
goto error;
|
|
|
|
return commit_creds(new);
|
|
|
|
error:
|
|
abort_creds(new);
|
|
return retval;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid)
|
|
{
|
|
const struct cred *cred = current_cred();
|
|
int retval;
|
|
|
|
if (!(retval = put_user(cred->uid, ruid)) &&
|
|
!(retval = put_user(cred->euid, euid)))
|
|
retval = put_user(cred->suid, suid);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* Same as above, but for rgid, egid, sgid.
|
|
*/
|
|
SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
|
|
{
|
|
const struct cred *old;
|
|
struct cred *new;
|
|
int retval;
|
|
|
|
new = prepare_creds();
|
|
if (!new)
|
|
return -ENOMEM;
|
|
old = current_cred();
|
|
|
|
retval = -EPERM;
|
|
if (!capable(CAP_SETGID)) {
|
|
if (rgid != (gid_t) -1 && rgid != old->gid &&
|
|
rgid != old->egid && rgid != old->sgid)
|
|
goto error;
|
|
if (egid != (gid_t) -1 && egid != old->gid &&
|
|
egid != old->egid && egid != old->sgid)
|
|
goto error;
|
|
if (sgid != (gid_t) -1 && sgid != old->gid &&
|
|
sgid != old->egid && sgid != old->sgid)
|
|
goto error;
|
|
}
|
|
|
|
if (rgid != (gid_t) -1)
|
|
new->gid = rgid;
|
|
if (egid != (gid_t) -1)
|
|
new->egid = egid;
|
|
if (sgid != (gid_t) -1)
|
|
new->sgid = sgid;
|
|
new->fsgid = new->egid;
|
|
|
|
return commit_creds(new);
|
|
|
|
error:
|
|
abort_creds(new);
|
|
return retval;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid)
|
|
{
|
|
const struct cred *cred = current_cred();
|
|
int retval;
|
|
|
|
if (!(retval = put_user(cred->gid, rgid)) &&
|
|
!(retval = put_user(cred->egid, egid)))
|
|
retval = put_user(cred->sgid, sgid);
|
|
|
|
return retval;
|
|
}
|
|
|
|
|
|
/*
|
|
* "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
|
|
* is used for "access()" and for the NFS daemon (letting nfsd stay at
|
|
* whatever uid it wants to). It normally shadows "euid", except when
|
|
* explicitly set by setfsuid() or for access..
|
|
*/
|
|
SYSCALL_DEFINE1(setfsuid, uid_t, uid)
|
|
{
|
|
const struct cred *old;
|
|
struct cred *new;
|
|
uid_t old_fsuid;
|
|
|
|
new = prepare_creds();
|
|
if (!new)
|
|
return current_fsuid();
|
|
old = current_cred();
|
|
old_fsuid = old->fsuid;
|
|
|
|
if (uid == old->uid || uid == old->euid ||
|
|
uid == old->suid || uid == old->fsuid ||
|
|
capable(CAP_SETUID)) {
|
|
if (uid != old_fsuid) {
|
|
new->fsuid = uid;
|
|
if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
|
|
goto change_okay;
|
|
}
|
|
}
|
|
|
|
abort_creds(new);
|
|
return old_fsuid;
|
|
|
|
change_okay:
|
|
commit_creds(new);
|
|
return old_fsuid;
|
|
}
|
|
|
|
/*
|
|
* Samma på svenska..
|
|
*/
|
|
SYSCALL_DEFINE1(setfsgid, gid_t, gid)
|
|
{
|
|
const struct cred *old;
|
|
struct cred *new;
|
|
gid_t old_fsgid;
|
|
|
|
new = prepare_creds();
|
|
if (!new)
|
|
return current_fsgid();
|
|
old = current_cred();
|
|
old_fsgid = old->fsgid;
|
|
|
|
if (gid == old->gid || gid == old->egid ||
|
|
gid == old->sgid || gid == old->fsgid ||
|
|
capable(CAP_SETGID)) {
|
|
if (gid != old_fsgid) {
|
|
new->fsgid = gid;
|
|
goto change_okay;
|
|
}
|
|
}
|
|
|
|
abort_creds(new);
|
|
return old_fsgid;
|
|
|
|
change_okay:
|
|
commit_creds(new);
|
|
return old_fsgid;
|
|
}
|
|
|
|
void do_sys_times(struct tms *tms)
|
|
{
|
|
cputime_t tgutime, tgstime, cutime, cstime;
|
|
|
|
spin_lock_irq(¤t->sighand->siglock);
|
|
thread_group_times(current, &tgutime, &tgstime);
|
|
cutime = current->signal->cutime;
|
|
cstime = current->signal->cstime;
|
|
spin_unlock_irq(¤t->sighand->siglock);
|
|
tms->tms_utime = cputime_to_clock_t(tgutime);
|
|
tms->tms_stime = cputime_to_clock_t(tgstime);
|
|
tms->tms_cutime = cputime_to_clock_t(cutime);
|
|
tms->tms_cstime = cputime_to_clock_t(cstime);
|
|
}
|
|
|
|
SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
|
|
{
|
|
if (tbuf) {
|
|
struct tms tmp;
|
|
|
|
do_sys_times(&tmp);
|
|
if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
|
|
return -EFAULT;
|
|
}
|
|
force_successful_syscall_return();
|
|
return (long) jiffies_64_to_clock_t(get_jiffies_64());
|
|
}
|
|
|
|
/*
|
|
* This needs some heavy checking ...
|
|
* I just haven't the stomach for it. I also don't fully
|
|
* understand sessions/pgrp etc. Let somebody who does explain it.
|
|
*
|
|
* OK, I think I have the protection semantics right.... this is really
|
|
* only important on a multi-user system anyway, to make sure one user
|
|
* can't send a signal to a process owned by another. -TYT, 12/12/91
|
|
*
|
|
* Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
|
|
* LBT 04.03.94
|
|
*/
|
|
SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
|
|
{
|
|
struct task_struct *p;
|
|
struct task_struct *group_leader = current->group_leader;
|
|
struct pid *pgrp;
|
|
int err;
|
|
|
|
if (!pid)
|
|
pid = task_pid_vnr(group_leader);
|
|
if (!pgid)
|
|
pgid = pid;
|
|
if (pgid < 0)
|
|
return -EINVAL;
|
|
rcu_read_lock();
|
|
|
|
/* From this point forward we keep holding onto the tasklist lock
|
|
* so that our parent does not change from under us. -DaveM
|
|
*/
|
|
write_lock_irq(&tasklist_lock);
|
|
|
|
err = -ESRCH;
|
|
p = find_task_by_vpid(pid);
|
|
if (!p)
|
|
goto out;
|
|
|
|
err = -EINVAL;
|
|
if (!thread_group_leader(p))
|
|
goto out;
|
|
|
|
if (same_thread_group(p->real_parent, group_leader)) {
|
|
err = -EPERM;
|
|
if (task_session(p) != task_session(group_leader))
|
|
goto out;
|
|
err = -EACCES;
|
|
if (p->did_exec)
|
|
goto out;
|
|
} else {
|
|
err = -ESRCH;
|
|
if (p != group_leader)
|
|
goto out;
|
|
}
|
|
|
|
err = -EPERM;
|
|
if (p->signal->leader)
|
|
goto out;
|
|
|
|
pgrp = task_pid(p);
|
|
if (pgid != pid) {
|
|
struct task_struct *g;
|
|
|
|
pgrp = find_vpid(pgid);
|
|
g = pid_task(pgrp, PIDTYPE_PGID);
|
|
if (!g || task_session(g) != task_session(group_leader))
|
|
goto out;
|
|
}
|
|
|
|
err = security_task_setpgid(p, pgid);
|
|
if (err)
|
|
goto out;
|
|
|
|
if (task_pgrp(p) != pgrp)
|
|
change_pid(p, PIDTYPE_PGID, pgrp);
|
|
|
|
err = 0;
|
|
out:
|
|
/* All paths lead to here, thus we are safe. -DaveM */
|
|
write_unlock_irq(&tasklist_lock);
|
|
rcu_read_unlock();
|
|
return err;
|
|
}
|
|
|
|
SYSCALL_DEFINE1(getpgid, pid_t, pid)
|
|
{
|
|
struct task_struct *p;
|
|
struct pid *grp;
|
|
int retval;
|
|
|
|
rcu_read_lock();
|
|
if (!pid)
|
|
grp = task_pgrp(current);
|
|
else {
|
|
retval = -ESRCH;
|
|
p = find_task_by_vpid(pid);
|
|
if (!p)
|
|
goto out;
|
|
grp = task_pgrp(p);
|
|
if (!grp)
|
|
goto out;
|
|
|
|
retval = security_task_getpgid(p);
|
|
if (retval)
|
|
goto out;
|
|
}
|
|
retval = pid_vnr(grp);
|
|
out:
|
|
rcu_read_unlock();
|
|
return retval;
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_SYS_GETPGRP
|
|
|
|
SYSCALL_DEFINE0(getpgrp)
|
|
{
|
|
return sys_getpgid(0);
|
|
}
|
|
|
|
#endif
|
|
|
|
SYSCALL_DEFINE1(getsid, pid_t, pid)
|
|
{
|
|
struct task_struct *p;
|
|
struct pid *sid;
|
|
int retval;
|
|
|
|
rcu_read_lock();
|
|
if (!pid)
|
|
sid = task_session(current);
|
|
else {
|
|
retval = -ESRCH;
|
|
p = find_task_by_vpid(pid);
|
|
if (!p)
|
|
goto out;
|
|
sid = task_session(p);
|
|
if (!sid)
|
|
goto out;
|
|
|
|
retval = security_task_getsid(p);
|
|
if (retval)
|
|
goto out;
|
|
}
|
|
retval = pid_vnr(sid);
|
|
out:
|
|
rcu_read_unlock();
|
|
return retval;
|
|
}
|
|
|
|
SYSCALL_DEFINE0(setsid)
|
|
{
|
|
struct task_struct *group_leader = current->group_leader;
|
|
struct pid *sid = task_pid(group_leader);
|
|
pid_t session = pid_vnr(sid);
|
|
int err = -EPERM;
|
|
|
|
write_lock_irq(&tasklist_lock);
|
|
/* Fail if I am already a session leader */
|
|
if (group_leader->signal->leader)
|
|
goto out;
|
|
|
|
/* Fail if a process group id already exists that equals the
|
|
* proposed session id.
|
|
*/
|
|
if (pid_task(sid, PIDTYPE_PGID))
|
|
goto out;
|
|
|
|
group_leader->signal->leader = 1;
|
|
__set_special_pids(sid);
|
|
|
|
proc_clear_tty(group_leader);
|
|
|
|
err = session;
|
|
out:
|
|
write_unlock_irq(&tasklist_lock);
|
|
if (err > 0) {
|
|
proc_sid_connector(group_leader);
|
|
sched_autogroup_create_attach(group_leader);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
DECLARE_RWSEM(uts_sem);
|
|
|
|
#ifdef COMPAT_UTS_MACHINE
|
|
#define override_architecture(name) \
|
|
(personality(current->personality) == PER_LINUX32 && \
|
|
copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
|
|
sizeof(COMPAT_UTS_MACHINE)))
|
|
#else
|
|
#define override_architecture(name) 0
|
|
#endif
|
|
|
|
SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
|
|
{
|
|
int errno = 0;
|
|
|
|
down_read(&uts_sem);
|
|
if (copy_to_user(name, utsname(), sizeof *name))
|
|
errno = -EFAULT;
|
|
up_read(&uts_sem);
|
|
|
|
if (!errno && override_architecture(name))
|
|
errno = -EFAULT;
|
|
return errno;
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_SYS_OLD_UNAME
|
|
/*
|
|
* Old cruft
|
|
*/
|
|
SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
|
|
{
|
|
int error = 0;
|
|
|
|
if (!name)
|
|
return -EFAULT;
|
|
|
|
down_read(&uts_sem);
|
|
if (copy_to_user(name, utsname(), sizeof(*name)))
|
|
error = -EFAULT;
|
|
up_read(&uts_sem);
|
|
|
|
if (!error && override_architecture(name))
|
|
error = -EFAULT;
|
|
return error;
|
|
}
|
|
|
|
SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
|
|
{
|
|
int error;
|
|
|
|
if (!name)
|
|
return -EFAULT;
|
|
if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
|
|
return -EFAULT;
|
|
|
|
down_read(&uts_sem);
|
|
error = __copy_to_user(&name->sysname, &utsname()->sysname,
|
|
__OLD_UTS_LEN);
|
|
error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
|
|
error |= __copy_to_user(&name->nodename, &utsname()->nodename,
|
|
__OLD_UTS_LEN);
|
|
error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
|
|
error |= __copy_to_user(&name->release, &utsname()->release,
|
|
__OLD_UTS_LEN);
|
|
error |= __put_user(0, name->release + __OLD_UTS_LEN);
|
|
error |= __copy_to_user(&name->version, &utsname()->version,
|
|
__OLD_UTS_LEN);
|
|
error |= __put_user(0, name->version + __OLD_UTS_LEN);
|
|
error |= __copy_to_user(&name->machine, &utsname()->machine,
|
|
__OLD_UTS_LEN);
|
|
error |= __put_user(0, name->machine + __OLD_UTS_LEN);
|
|
up_read(&uts_sem);
|
|
|
|
if (!error && override_architecture(name))
|
|
error = -EFAULT;
|
|
return error ? -EFAULT : 0;
|
|
}
|
|
#endif
|
|
|
|
SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
|
|
{
|
|
int errno;
|
|
char tmp[__NEW_UTS_LEN];
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
if (len < 0 || len > __NEW_UTS_LEN)
|
|
return -EINVAL;
|
|
down_write(&uts_sem);
|
|
errno = -EFAULT;
|
|
if (!copy_from_user(tmp, name, len)) {
|
|
struct new_utsname *u = utsname();
|
|
|
|
memcpy(u->nodename, tmp, len);
|
|
memset(u->nodename + len, 0, sizeof(u->nodename) - len);
|
|
errno = 0;
|
|
}
|
|
up_write(&uts_sem);
|
|
return errno;
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_SYS_GETHOSTNAME
|
|
|
|
SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
|
|
{
|
|
int i, errno;
|
|
struct new_utsname *u;
|
|
|
|
if (len < 0)
|
|
return -EINVAL;
|
|
down_read(&uts_sem);
|
|
u = utsname();
|
|
i = 1 + strlen(u->nodename);
|
|
if (i > len)
|
|
i = len;
|
|
errno = 0;
|
|
if (copy_to_user(name, u->nodename, i))
|
|
errno = -EFAULT;
|
|
up_read(&uts_sem);
|
|
return errno;
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
* Only setdomainname; getdomainname can be implemented by calling
|
|
* uname()
|
|
*/
|
|
SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
|
|
{
|
|
int errno;
|
|
char tmp[__NEW_UTS_LEN];
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
if (len < 0 || len > __NEW_UTS_LEN)
|
|
return -EINVAL;
|
|
|
|
down_write(&uts_sem);
|
|
errno = -EFAULT;
|
|
if (!copy_from_user(tmp, name, len)) {
|
|
struct new_utsname *u = utsname();
|
|
|
|
memcpy(u->domainname, tmp, len);
|
|
memset(u->domainname + len, 0, sizeof(u->domainname) - len);
|
|
errno = 0;
|
|
}
|
|
up_write(&uts_sem);
|
|
return errno;
|
|
}
|
|
|
|
SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
|
|
{
|
|
struct rlimit value;
|
|
int ret;
|
|
|
|
ret = do_prlimit(current, resource, NULL, &value);
|
|
if (!ret)
|
|
ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
|
|
|
|
/*
|
|
* Back compatibility for getrlimit. Needed for some apps.
|
|
*/
|
|
|
|
SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
|
|
struct rlimit __user *, rlim)
|
|
{
|
|
struct rlimit x;
|
|
if (resource >= RLIM_NLIMITS)
|
|
return -EINVAL;
|
|
|
|
task_lock(current->group_leader);
|
|
x = current->signal->rlim[resource];
|
|
task_unlock(current->group_leader);
|
|
if (x.rlim_cur > 0x7FFFFFFF)
|
|
x.rlim_cur = 0x7FFFFFFF;
|
|
if (x.rlim_max > 0x7FFFFFFF)
|
|
x.rlim_max = 0x7FFFFFFF;
|
|
return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
|
|
}
|
|
|
|
#endif
|
|
|
|
static inline bool rlim64_is_infinity(__u64 rlim64)
|
|
{
|
|
#if BITS_PER_LONG < 64
|
|
return rlim64 >= ULONG_MAX;
|
|
#else
|
|
return rlim64 == RLIM64_INFINITY;
|
|
#endif
|
|
}
|
|
|
|
static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
|
|
{
|
|
if (rlim->rlim_cur == RLIM_INFINITY)
|
|
rlim64->rlim_cur = RLIM64_INFINITY;
|
|
else
|
|
rlim64->rlim_cur = rlim->rlim_cur;
|
|
if (rlim->rlim_max == RLIM_INFINITY)
|
|
rlim64->rlim_max = RLIM64_INFINITY;
|
|
else
|
|
rlim64->rlim_max = rlim->rlim_max;
|
|
}
|
|
|
|
static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
|
|
{
|
|
if (rlim64_is_infinity(rlim64->rlim_cur))
|
|
rlim->rlim_cur = RLIM_INFINITY;
|
|
else
|
|
rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
|
|
if (rlim64_is_infinity(rlim64->rlim_max))
|
|
rlim->rlim_max = RLIM_INFINITY;
|
|
else
|
|
rlim->rlim_max = (unsigned long)rlim64->rlim_max;
|
|
}
|
|
|
|
/* make sure you are allowed to change @tsk limits before calling this */
|
|
int do_prlimit(struct task_struct *tsk, unsigned int resource,
|
|
struct rlimit *new_rlim, struct rlimit *old_rlim)
|
|
{
|
|
struct rlimit *rlim;
|
|
int retval = 0;
|
|
|
|
if (resource >= RLIM_NLIMITS)
|
|
return -EINVAL;
|
|
if (new_rlim) {
|
|
if (new_rlim->rlim_cur > new_rlim->rlim_max)
|
|
return -EINVAL;
|
|
if (resource == RLIMIT_NOFILE &&
|
|
new_rlim->rlim_max > sysctl_nr_open)
|
|
return -EPERM;
|
|
}
|
|
|
|
/* protect tsk->signal and tsk->sighand from disappearing */
|
|
read_lock(&tasklist_lock);
|
|
if (!tsk->sighand) {
|
|
retval = -ESRCH;
|
|
goto out;
|
|
}
|
|
|
|
rlim = tsk->signal->rlim + resource;
|
|
task_lock(tsk->group_leader);
|
|
if (new_rlim) {
|
|
if (new_rlim->rlim_max > rlim->rlim_max &&
|
|
!capable(CAP_SYS_RESOURCE))
|
|
retval = -EPERM;
|
|
if (!retval)
|
|
retval = security_task_setrlimit(tsk->group_leader,
|
|
resource, new_rlim);
|
|
if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
|
|
/*
|
|
* The caller is asking for an immediate RLIMIT_CPU
|
|
* expiry. But we use the zero value to mean "it was
|
|
* never set". So let's cheat and make it one second
|
|
* instead
|
|
*/
|
|
new_rlim->rlim_cur = 1;
|
|
}
|
|
}
|
|
if (!retval) {
|
|
if (old_rlim)
|
|
*old_rlim = *rlim;
|
|
if (new_rlim)
|
|
*rlim = *new_rlim;
|
|
}
|
|
task_unlock(tsk->group_leader);
|
|
|
|
/*
|
|
* RLIMIT_CPU handling. Note that the kernel fails to return an error
|
|
* code if it rejected the user's attempt to set RLIMIT_CPU. This is a
|
|
* very long-standing error, and fixing it now risks breakage of
|
|
* applications, so we live with it
|
|
*/
|
|
if (!retval && new_rlim && resource == RLIMIT_CPU &&
|
|
new_rlim->rlim_cur != RLIM_INFINITY)
|
|
update_rlimit_cpu(tsk, new_rlim->rlim_cur);
|
|
out:
|
|
read_unlock(&tasklist_lock);
|
|
return retval;
|
|
}
|
|
|
|
/* rcu lock must be held */
|
|
static int check_prlimit_permission(struct task_struct *task)
|
|
{
|
|
const struct cred *cred = current_cred(), *tcred;
|
|
|
|
tcred = __task_cred(task);
|
|
if (current != task &&
|
|
(cred->uid != tcred->euid ||
|
|
cred->uid != tcred->suid ||
|
|
cred->uid != tcred->uid ||
|
|
cred->gid != tcred->egid ||
|
|
cred->gid != tcred->sgid ||
|
|
cred->gid != tcred->gid) &&
|
|
!capable(CAP_SYS_RESOURCE)) {
|
|
return -EPERM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
|
|
const struct rlimit64 __user *, new_rlim,
|
|
struct rlimit64 __user *, old_rlim)
|
|
{
|
|
struct rlimit64 old64, new64;
|
|
struct rlimit old, new;
|
|
struct task_struct *tsk;
|
|
int ret;
|
|
|
|
if (new_rlim) {
|
|
if (copy_from_user(&new64, new_rlim, sizeof(new64)))
|
|
return -EFAULT;
|
|
rlim64_to_rlim(&new64, &new);
|
|
}
|
|
|
|
rcu_read_lock();
|
|
tsk = pid ? find_task_by_vpid(pid) : current;
|
|
if (!tsk) {
|
|
rcu_read_unlock();
|
|
return -ESRCH;
|
|
}
|
|
ret = check_prlimit_permission(tsk);
|
|
if (ret) {
|
|
rcu_read_unlock();
|
|
return ret;
|
|
}
|
|
get_task_struct(tsk);
|
|
rcu_read_unlock();
|
|
|
|
ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
|
|
old_rlim ? &old : NULL);
|
|
|
|
if (!ret && old_rlim) {
|
|
rlim_to_rlim64(&old, &old64);
|
|
if (copy_to_user(old_rlim, &old64, sizeof(old64)))
|
|
ret = -EFAULT;
|
|
}
|
|
|
|
put_task_struct(tsk);
|
|
return ret;
|
|
}
|
|
|
|
SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
|
|
{
|
|
struct rlimit new_rlim;
|
|
|
|
if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
|
|
return -EFAULT;
|
|
return do_prlimit(current, resource, &new_rlim, NULL);
|
|
}
|
|
|
|
/*
|
|
* It would make sense to put struct rusage in the task_struct,
|
|
* except that would make the task_struct be *really big*. After
|
|
* task_struct gets moved into malloc'ed memory, it would
|
|
* make sense to do this. It will make moving the rest of the information
|
|
* a lot simpler! (Which we're not doing right now because we're not
|
|
* measuring them yet).
|
|
*
|
|
* When sampling multiple threads for RUSAGE_SELF, under SMP we might have
|
|
* races with threads incrementing their own counters. But since word
|
|
* reads are atomic, we either get new values or old values and we don't
|
|
* care which for the sums. We always take the siglock to protect reading
|
|
* the c* fields from p->signal from races with exit.c updating those
|
|
* fields when reaping, so a sample either gets all the additions of a
|
|
* given child after it's reaped, or none so this sample is before reaping.
|
|
*
|
|
* Locking:
|
|
* We need to take the siglock for CHILDEREN, SELF and BOTH
|
|
* for the cases current multithreaded, non-current single threaded
|
|
* non-current multithreaded. Thread traversal is now safe with
|
|
* the siglock held.
|
|
* Strictly speaking, we donot need to take the siglock if we are current and
|
|
* single threaded, as no one else can take our signal_struct away, no one
|
|
* else can reap the children to update signal->c* counters, and no one else
|
|
* can race with the signal-> fields. If we do not take any lock, the
|
|
* signal-> fields could be read out of order while another thread was just
|
|
* exiting. So we should place a read memory barrier when we avoid the lock.
|
|
* On the writer side, write memory barrier is implied in __exit_signal
|
|
* as __exit_signal releases the siglock spinlock after updating the signal->
|
|
* fields. But we don't do this yet to keep things simple.
|
|
*
|
|
*/
|
|
|
|
static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
|
|
{
|
|
r->ru_nvcsw += t->nvcsw;
|
|
r->ru_nivcsw += t->nivcsw;
|
|
r->ru_minflt += t->min_flt;
|
|
r->ru_majflt += t->maj_flt;
|
|
r->ru_inblock += task_io_get_inblock(t);
|
|
r->ru_oublock += task_io_get_oublock(t);
|
|
}
|
|
|
|
static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
|
|
{
|
|
struct task_struct *t;
|
|
unsigned long flags;
|
|
cputime_t tgutime, tgstime, utime, stime;
|
|
unsigned long maxrss = 0;
|
|
|
|
memset((char *) r, 0, sizeof *r);
|
|
utime = stime = cputime_zero;
|
|
|
|
if (who == RUSAGE_THREAD) {
|
|
task_times(current, &utime, &stime);
|
|
accumulate_thread_rusage(p, r);
|
|
maxrss = p->signal->maxrss;
|
|
goto out;
|
|
}
|
|
|
|
if (!lock_task_sighand(p, &flags))
|
|
return;
|
|
|
|
switch (who) {
|
|
case RUSAGE_BOTH:
|
|
case RUSAGE_CHILDREN:
|
|
utime = p->signal->cutime;
|
|
stime = p->signal->cstime;
|
|
r->ru_nvcsw = p->signal->cnvcsw;
|
|
r->ru_nivcsw = p->signal->cnivcsw;
|
|
r->ru_minflt = p->signal->cmin_flt;
|
|
r->ru_majflt = p->signal->cmaj_flt;
|
|
r->ru_inblock = p->signal->cinblock;
|
|
r->ru_oublock = p->signal->coublock;
|
|
maxrss = p->signal->cmaxrss;
|
|
|
|
if (who == RUSAGE_CHILDREN)
|
|
break;
|
|
|
|
case RUSAGE_SELF:
|
|
thread_group_times(p, &tgutime, &tgstime);
|
|
utime = cputime_add(utime, tgutime);
|
|
stime = cputime_add(stime, tgstime);
|
|
r->ru_nvcsw += p->signal->nvcsw;
|
|
r->ru_nivcsw += p->signal->nivcsw;
|
|
r->ru_minflt += p->signal->min_flt;
|
|
r->ru_majflt += p->signal->maj_flt;
|
|
r->ru_inblock += p->signal->inblock;
|
|
r->ru_oublock += p->signal->oublock;
|
|
if (maxrss < p->signal->maxrss)
|
|
maxrss = p->signal->maxrss;
|
|
t = p;
|
|
do {
|
|
accumulate_thread_rusage(t, r);
|
|
t = next_thread(t);
|
|
} while (t != p);
|
|
break;
|
|
|
|
default:
|
|
BUG();
|
|
}
|
|
unlock_task_sighand(p, &flags);
|
|
|
|
out:
|
|
cputime_to_timeval(utime, &r->ru_utime);
|
|
cputime_to_timeval(stime, &r->ru_stime);
|
|
|
|
if (who != RUSAGE_CHILDREN) {
|
|
struct mm_struct *mm = get_task_mm(p);
|
|
if (mm) {
|
|
setmax_mm_hiwater_rss(&maxrss, mm);
|
|
mmput(mm);
|
|
}
|
|
}
|
|
r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
|
|
}
|
|
|
|
int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
|
|
{
|
|
struct rusage r;
|
|
k_getrusage(p, who, &r);
|
|
return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
|
|
}
|
|
|
|
SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
|
|
{
|
|
if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
|
|
who != RUSAGE_THREAD)
|
|
return -EINVAL;
|
|
return getrusage(current, who, ru);
|
|
}
|
|
|
|
SYSCALL_DEFINE1(umask, int, mask)
|
|
{
|
|
mask = xchg(¤t->fs->umask, mask & S_IRWXUGO);
|
|
return mask;
|
|
}
|
|
|
|
SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
|
|
unsigned long, arg4, unsigned long, arg5)
|
|
{
|
|
struct task_struct *me = current;
|
|
unsigned char comm[sizeof(me->comm)];
|
|
long error;
|
|
|
|
error = security_task_prctl(option, arg2, arg3, arg4, arg5);
|
|
if (error != -ENOSYS)
|
|
return error;
|
|
|
|
error = 0;
|
|
switch (option) {
|
|
case PR_SET_PDEATHSIG:
|
|
if (!valid_signal(arg2)) {
|
|
error = -EINVAL;
|
|
break;
|
|
}
|
|
me->pdeath_signal = arg2;
|
|
error = 0;
|
|
break;
|
|
case PR_GET_PDEATHSIG:
|
|
error = put_user(me->pdeath_signal, (int __user *)arg2);
|
|
break;
|
|
case PR_GET_DUMPABLE:
|
|
error = get_dumpable(me->mm);
|
|
break;
|
|
case PR_SET_DUMPABLE:
|
|
if (arg2 < 0 || arg2 > 1) {
|
|
error = -EINVAL;
|
|
break;
|
|
}
|
|
set_dumpable(me->mm, arg2);
|
|
error = 0;
|
|
break;
|
|
|
|
case PR_SET_UNALIGN:
|
|
error = SET_UNALIGN_CTL(me, arg2);
|
|
break;
|
|
case PR_GET_UNALIGN:
|
|
error = GET_UNALIGN_CTL(me, arg2);
|
|
break;
|
|
case PR_SET_FPEMU:
|
|
error = SET_FPEMU_CTL(me, arg2);
|
|
break;
|
|
case PR_GET_FPEMU:
|
|
error = GET_FPEMU_CTL(me, arg2);
|
|
break;
|
|
case PR_SET_FPEXC:
|
|
error = SET_FPEXC_CTL(me, arg2);
|
|
break;
|
|
case PR_GET_FPEXC:
|
|
error = GET_FPEXC_CTL(me, arg2);
|
|
break;
|
|
case PR_GET_TIMING:
|
|
error = PR_TIMING_STATISTICAL;
|
|
break;
|
|
case PR_SET_TIMING:
|
|
if (arg2 != PR_TIMING_STATISTICAL)
|
|
error = -EINVAL;
|
|
else
|
|
error = 0;
|
|
break;
|
|
|
|
case PR_SET_NAME:
|
|
comm[sizeof(me->comm)-1] = 0;
|
|
if (strncpy_from_user(comm, (char __user *)arg2,
|
|
sizeof(me->comm) - 1) < 0)
|
|
return -EFAULT;
|
|
set_task_comm(me, comm);
|
|
return 0;
|
|
case PR_GET_NAME:
|
|
get_task_comm(comm, me);
|
|
if (copy_to_user((char __user *)arg2, comm,
|
|
sizeof(comm)))
|
|
return -EFAULT;
|
|
return 0;
|
|
case PR_GET_ENDIAN:
|
|
error = GET_ENDIAN(me, arg2);
|
|
break;
|
|
case PR_SET_ENDIAN:
|
|
error = SET_ENDIAN(me, arg2);
|
|
break;
|
|
|
|
case PR_GET_SECCOMP:
|
|
error = prctl_get_seccomp();
|
|
break;
|
|
case PR_SET_SECCOMP:
|
|
error = prctl_set_seccomp(arg2);
|
|
break;
|
|
case PR_GET_TSC:
|
|
error = GET_TSC_CTL(arg2);
|
|
break;
|
|
case PR_SET_TSC:
|
|
error = SET_TSC_CTL(arg2);
|
|
break;
|
|
case PR_TASK_PERF_EVENTS_DISABLE:
|
|
error = perf_event_task_disable();
|
|
break;
|
|
case PR_TASK_PERF_EVENTS_ENABLE:
|
|
error = perf_event_task_enable();
|
|
break;
|
|
case PR_GET_TIMERSLACK:
|
|
error = current->timer_slack_ns;
|
|
break;
|
|
case PR_SET_TIMERSLACK:
|
|
if (arg2 <= 0)
|
|
current->timer_slack_ns =
|
|
current->default_timer_slack_ns;
|
|
else
|
|
current->timer_slack_ns = arg2;
|
|
error = 0;
|
|
break;
|
|
case PR_MCE_KILL:
|
|
if (arg4 | arg5)
|
|
return -EINVAL;
|
|
switch (arg2) {
|
|
case PR_MCE_KILL_CLEAR:
|
|
if (arg3 != 0)
|
|
return -EINVAL;
|
|
current->flags &= ~PF_MCE_PROCESS;
|
|
break;
|
|
case PR_MCE_KILL_SET:
|
|
current->flags |= PF_MCE_PROCESS;
|
|
if (arg3 == PR_MCE_KILL_EARLY)
|
|
current->flags |= PF_MCE_EARLY;
|
|
else if (arg3 == PR_MCE_KILL_LATE)
|
|
current->flags &= ~PF_MCE_EARLY;
|
|
else if (arg3 == PR_MCE_KILL_DEFAULT)
|
|
current->flags &=
|
|
~(PF_MCE_EARLY|PF_MCE_PROCESS);
|
|
else
|
|
return -EINVAL;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
error = 0;
|
|
break;
|
|
case PR_MCE_KILL_GET:
|
|
if (arg2 | arg3 | arg4 | arg5)
|
|
return -EINVAL;
|
|
if (current->flags & PF_MCE_PROCESS)
|
|
error = (current->flags & PF_MCE_EARLY) ?
|
|
PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
|
|
else
|
|
error = PR_MCE_KILL_DEFAULT;
|
|
break;
|
|
default:
|
|
error = -EINVAL;
|
|
break;
|
|
}
|
|
return error;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
|
|
struct getcpu_cache __user *, unused)
|
|
{
|
|
int err = 0;
|
|
int cpu = raw_smp_processor_id();
|
|
if (cpup)
|
|
err |= put_user(cpu, cpup);
|
|
if (nodep)
|
|
err |= put_user(cpu_to_node(cpu), nodep);
|
|
return err ? -EFAULT : 0;
|
|
}
|
|
|
|
char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
|
|
|
|
static void argv_cleanup(struct subprocess_info *info)
|
|
{
|
|
argv_free(info->argv);
|
|
}
|
|
|
|
/**
|
|
* orderly_poweroff - Trigger an orderly system poweroff
|
|
* @force: force poweroff if command execution fails
|
|
*
|
|
* This may be called from any context to trigger a system shutdown.
|
|
* If the orderly shutdown fails, it will force an immediate shutdown.
|
|
*/
|
|
int orderly_poweroff(bool force)
|
|
{
|
|
int argc;
|
|
char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
|
|
static char *envp[] = {
|
|
"HOME=/",
|
|
"PATH=/sbin:/bin:/usr/sbin:/usr/bin",
|
|
NULL
|
|
};
|
|
int ret = -ENOMEM;
|
|
struct subprocess_info *info;
|
|
|
|
if (argv == NULL) {
|
|
printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
|
|
__func__, poweroff_cmd);
|
|
goto out;
|
|
}
|
|
|
|
info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC);
|
|
if (info == NULL) {
|
|
argv_free(argv);
|
|
goto out;
|
|
}
|
|
|
|
call_usermodehelper_setfns(info, NULL, argv_cleanup, NULL);
|
|
|
|
ret = call_usermodehelper_exec(info, UMH_NO_WAIT);
|
|
|
|
out:
|
|
if (ret && force) {
|
|
printk(KERN_WARNING "Failed to start orderly shutdown: "
|
|
"forcing the issue\n");
|
|
|
|
/* I guess this should try to kick off some daemon to
|
|
sync and poweroff asap. Or not even bother syncing
|
|
if we're doing an emergency shutdown? */
|
|
emergency_sync();
|
|
kernel_power_off();
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(orderly_poweroff);
|