/* * linux/kernel/sys.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/config.h> #include <linux/module.h> #include <linux/mm.h> #include <linux/utsname.h> #include <linux/mman.h> #include <linux/smp_lock.h> #include <linux/notifier.h> #include <linux/reboot.h> #include <linux/prctl.h> #include <linux/init.h> #include <linux/highuid.h> #include <linux/fs.h> #include <linux/tqueue.h> #include <linux/device.h> #include <linux/times.h> #include <linux/security.h> #include <asm/uaccess.h> #include <asm/io.h> #include <asm/unistd.h> #ifndef SET_UNALIGN_CTL # define SET_UNALIGN_CTL(a,b) (-EINVAL) #endif #ifndef GET_UNALIGN_CTL # define GET_UNALIGN_CTL(a,b) (-EINVAL) #endif #ifndef SET_FPEMU_CTL # define SET_FPEMU_CTL(a,b) (-EINVAL) #endif #ifndef GET_FPEMU_CTL # define GET_FPEMU_CTL(a,b) (-EINVAL) #endif #ifndef SET_FPEXC_CTL # define SET_FPEXC_CTL(a,b) (-EINVAL) #endif #ifndef GET_FPEXC_CTL # define GET_FPEXC_CTL(a,b) (-EINVAL) #endif /* * this is where the system-wide overflow UID and GID are defined, for * architectures that now have 32-bit UID/GID but didn't in the past */ int overflowuid = DEFAULT_OVERFLOWUID; int overflowgid = DEFAULT_OVERFLOWGID; /* * the same as above, but for filesystems which can only store a 16-bit * UID and GID. as such, this is needed on all architectures */ int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; /* * this indicates whether you can reboot with ctrl-alt-del: the default is yes */ int C_A_D = 1; int cad_pid = 1; extern int system_running; /* * Notifier list for kernel code which wants to be called * at shutdown. This is used to stop any idling DMA operations * and the like. */ static struct notifier_block *reboot_notifier_list; rwlock_t notifier_lock = RW_LOCK_UNLOCKED; /** * notifier_chain_register - Add notifier to a notifier chain * @list: Pointer to root list pointer * @n: New entry in notifier chain * * Adds a notifier to a notifier chain. * * Currently always returns zero. */ int notifier_chain_register(struct notifier_block **list, struct notifier_block *n) { write_lock(¬ifier_lock); while(*list) { if(n->priority > (*list)->priority) break; list= &((*list)->next); } n->next = *list; *list=n; write_unlock(¬ifier_lock); return 0; } /** * notifier_chain_unregister - Remove notifier from a notifier chain * @nl: Pointer to root list pointer * @n: New entry in notifier chain * * Removes a notifier from a notifier chain. * * Returns zero on success, or %-ENOENT on failure. */ int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n) { write_lock(¬ifier_lock); while((*nl)!=NULL) { if((*nl)==n) { *nl=n->next; write_unlock(¬ifier_lock); return 0; } nl=&((*nl)->next); } write_unlock(¬ifier_lock); return -ENOENT; } /** * notifier_call_chain - Call functions in a notifier chain * @n: Pointer to root pointer of notifier chain * @val: Value passed unmodified to notifier function * @v: Pointer passed unmodified to notifier function * * Calls each function in a notifier chain in turn. * * If the return value of the notifier can be and'd * with %NOTIFY_STOP_MASK, then notifier_call_chain * will return immediately, with the return value of * the notifier function which halted execution. * Otherwise, the return value is the return value * of the last notifier function called. */ int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v) { int ret=NOTIFY_DONE; struct notifier_block *nb = *n; while(nb) { ret=nb->notifier_call(nb,val,v); if(ret&NOTIFY_STOP_MASK) { return ret; } nb=nb->next; } return ret; } /** * register_reboot_notifier - Register function to be called at reboot time * @nb: Info about notifier function to be called * * Registers a function with the list of functions * to be called at reboot time. * * Currently always returns zero, as notifier_chain_register * always returns zero. */ int register_reboot_notifier(struct notifier_block * nb) { return notifier_chain_register(&reboot_notifier_list, nb); } /** * unregister_reboot_notifier - Unregister previously registered reboot notifier * @nb: Hook to be unregistered * * Unregisters a previously registered reboot * notifier function. * * Returns zero on success, or %-ENOENT on failure. */ int unregister_reboot_notifier(struct notifier_block * nb) { return notifier_chain_unregister(&reboot_notifier_list, nb); } asmlinkage long sys_ni_syscall(void) { return -ENOSYS; } cond_syscall(sys_nfsservctl) cond_syscall(sys_quotactl) cond_syscall(sys_acct) static int set_one_prio(struct task_struct *p, int niceval, int error) { if (p->uid != current->euid && p->uid != current->uid && !capable(CAP_SYS_NICE)) { error = -EPERM; goto out; } if (error == -ESRCH) error = 0; if (niceval < task_nice(p) && !capable(CAP_SYS_NICE)) error = -EACCES; else set_user_nice(p, niceval); out: return error; } asmlinkage long sys_setpriority(int which, int who, int niceval) { struct task_struct *g, *p; struct user_struct *user; struct pid *pid; struct list_head *l; int error = -EINVAL; if (which > 2 || which < 0) goto out; /* normalize: avoid signed division (rounding problems) */ error = -ESRCH; if (niceval < -20) niceval = -20; if (niceval > 19) niceval = 19; read_lock(&tasklist_lock); switch (which) { case PRIO_PROCESS: if (!who) who = current->pid; p = find_task_by_pid(who); if (p) error = set_one_prio(p, niceval, error); break; case PRIO_PGRP: if (!who) who = current->pgrp; for_each_task_pid(who, PIDTYPE_PGID, p, l, pid) error = set_one_prio(p, niceval, error); break; case PRIO_USER: if (!who) user = current->user; else user = find_user(who); if (!user) goto out_unlock; do_each_thread(g, p) if (p->uid == who) error = set_one_prio(p, niceval, error); while_each_thread(g, p); break; } out_unlock: read_unlock(&tasklist_lock); out: return error; } /* * Ugh. To avoid negative return values, "getpriority()" will * not return the normal nice-value, but a negated value that * has been offset by 20 (ie it returns 40..1 instead of -20..19) * to stay compatible. */ asmlinkage long sys_getpriority(int which, int who) { struct task_struct *g, *p; struct list_head *l; struct pid *pid; struct user_struct *user; long niceval, retval = -ESRCH; if (which > 2 || which < 0) return -EINVAL; read_lock(&tasklist_lock); switch (which) { case PRIO_PROCESS: if (!who) who = current->pid; p = find_task_by_pid(who); if (p) { niceval = 20 - task_nice(p); if (niceval > retval) retval = niceval; } break; case PRIO_PGRP: if (!who) who = current->pgrp; for_each_task_pid(who, PIDTYPE_PGID, p, l, pid) { niceval = 20 - task_nice(p); if (niceval > retval) retval = niceval; } break; case PRIO_USER: if (!who) user = current->user; else user = find_user(who); if (!user) goto out_unlock; do_each_thread(g, p) if (p->uid == who) { niceval = 20 - task_nice(p); if (niceval > retval) retval = niceval; } while_each_thread(g, p); break; } out_unlock: read_unlock(&tasklist_lock); return retval; } /* * Reboot system call: for obvious reasons only root may call it, * and even root needs to set up some magic numbers in the registers * so that some mistake won't make this reboot the whole machine. * You can also set the meaning of the ctrl-alt-del-key here. * * reboot doesn't sync: do that yourself before calling this. */ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void * arg) { char buffer[256]; /* We only trust the superuser with rebooting the system. */ if (!capable(CAP_SYS_BOOT)) return -EPERM; /* For safety, we require "magic" arguments. */ if (magic1 != LINUX_REBOOT_MAGIC1 || (magic2 != LINUX_REBOOT_MAGIC2 && magic2 != LINUX_REBOOT_MAGIC2A && magic2 != LINUX_REBOOT_MAGIC2B)) return -EINVAL; lock_kernel(); switch (cmd) { case LINUX_REBOOT_CMD_RESTART: notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL); system_running = 0; device_shutdown(); printk(KERN_EMERG "Restarting system.\n"); machine_restart(NULL); break; case LINUX_REBOOT_CMD_CAD_ON: C_A_D = 1; break; case LINUX_REBOOT_CMD_CAD_OFF: C_A_D = 0; break; case LINUX_REBOOT_CMD_HALT: notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL); system_running = 0; device_shutdown(); printk(KERN_EMERG "System halted.\n"); machine_halt(); do_exit(0); break; case LINUX_REBOOT_CMD_POWER_OFF: notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL); system_running = 0; device_shutdown(); printk(KERN_EMERG "Power down.\n"); machine_power_off(); do_exit(0); break; case LINUX_REBOOT_CMD_RESTART2: if (strncpy_from_user(&buffer[0], (char *)arg, sizeof(buffer) - 1) < 0) { unlock_kernel(); return -EFAULT; } buffer[sizeof(buffer) - 1] = '\0'; notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer); system_running = 0; device_shutdown(); printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer); machine_restart(buffer); break; #ifdef CONFIG_SOFTWARE_SUSPEND case LINUX_REBOOT_CMD_SW_SUSPEND: if(!software_suspend_enabled) return -EAGAIN; software_suspend(); do_exit(0); break; #endif default: unlock_kernel(); return -EINVAL; } unlock_kernel(); return 0; } static void deferred_cad(void *dummy) { notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL); machine_restart(NULL); } /* * This function gets called by ctrl-alt-del - ie the keyboard interrupt. * As it's called within an interrupt, it may NOT sync: the only choice * is whether to reboot at once, or just ignore the ctrl-alt-del. */ void ctrl_alt_del(void) { static struct tq_struct cad_tq = { .routine = deferred_cad, }; if (C_A_D) schedule_task(&cad_tq); else kill_proc(cad_pid, SIGINT, 1); } /* * Unprivileged users may change the real gid to the effective gid * or vice versa. (BSD-style) * * If you set the real gid at all, or set the effective gid to a value not * equal to the real gid, then the saved gid is set to the new effective gid. * * 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. * * SMP: There are not races, the GIDs are checked only by filesystem * operations (as far as semantic preservation is concerned). */ asmlinkage long sys_setregid(gid_t rgid, gid_t egid) { int old_rgid = current->gid; int old_egid = current->egid; int new_rgid = old_rgid; int new_egid = old_egid; int retval; retval = security_ops->task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE); if (retval) return retval; if (rgid != (gid_t) -1) { if ((old_rgid == rgid) || (current->egid==rgid) || capable(CAP_SETGID)) new_rgid = rgid; else return -EPERM; } if (egid != (gid_t) -1) { if ((old_rgid == egid) || (current->egid == egid) || (current->sgid == egid) || capable(CAP_SETGID)) new_egid = egid; else { return -EPERM; } } if (new_egid != old_egid) { current->mm->dumpable = 0; wmb(); } if (rgid != (gid_t) -1 || (egid != (gid_t) -1 && egid != old_rgid)) current->sgid = new_egid; current->fsgid = new_egid; current->egid = new_egid; current->gid = new_rgid; return 0; } /* * setgid() is implemented like SysV w/ SAVED_IDS * * SMP: Same implicit races as above. */ asmlinkage long sys_setgid(gid_t gid) { int old_egid = current->egid; int retval; retval = security_ops->task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID); if (retval) return retval; if (capable(CAP_SETGID)) { if(old_egid != gid) { current->mm->dumpable=0; wmb(); } current->gid = current->egid = current->sgid = current->fsgid = gid; } else if ((gid == current->gid) || (gid == current->sgid)) { if(old_egid != gid) { current->mm->dumpable=0; wmb(); } current->egid = current->fsgid = gid; } else return -EPERM; return 0; } static int set_user(uid_t new_ruid, int dumpclear) { struct user_struct *new_user, *old_user; /* What if a process setreuid()'s and this brings the * new uid over his NPROC rlimit? We can check this now * cheaply with the new uid cache, so if it matters * we should be checking for it. -DaveM */ new_user = alloc_uid(new_ruid); if (!new_user) return -EAGAIN; old_user = current->user; atomic_dec(&old_user->processes); atomic_inc(&new_user->processes); if(dumpclear) { current->mm->dumpable = 0; wmb(); } current->uid = new_ruid; current->user = new_user; free_uid(old_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. */ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) { int old_ruid, old_euid, old_suid, new_ruid, new_euid; int retval; retval = security_ops->task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE); if (retval) return retval; new_ruid = old_ruid = current->uid; new_euid = old_euid = current->euid; old_suid = current->suid; if (ruid != (uid_t) -1) { new_ruid = ruid; if ((old_ruid != ruid) && (current->euid != ruid) && !capable(CAP_SETUID)) return -EPERM; } if (euid != (uid_t) -1) { new_euid = euid; if ((old_ruid != euid) && (current->euid != euid) && (current->suid != euid) && !capable(CAP_SETUID)) return -EPERM; } if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0) return -EAGAIN; if (new_euid != old_euid) { current->mm->dumpable=0; wmb(); } current->fsuid = current->euid = new_euid; if (ruid != (uid_t) -1 || (euid != (uid_t) -1 && euid != old_ruid)) current->suid = current->euid; current->fsuid = current->euid; return security_ops->task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE); } /* * 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. */ asmlinkage long sys_setuid(uid_t uid) { int old_euid = current->euid; int old_ruid, old_suid, new_ruid, new_suid; int retval; retval = security_ops->task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID); if (retval) return retval; old_ruid = new_ruid = current->uid; old_suid = current->suid; new_suid = old_suid; if (capable(CAP_SETUID)) { if (uid != old_ruid && set_user(uid, old_euid != uid) < 0) return -EAGAIN; new_suid = uid; } else if ((uid != current->uid) && (uid != new_suid)) return -EPERM; if (old_euid != uid) { current->mm->dumpable = 0; wmb(); } current->fsuid = current->euid = uid; current->suid = new_suid; return security_ops->task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID); } /* * This function implements a generic ability to update ruid, euid, * and suid. This allows you to implement the 4.4 compatible seteuid(). */ asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) { int old_ruid = current->uid; int old_euid = current->euid; int old_suid = current->suid; int retval; retval = security_ops->task_setuid(ruid, euid, suid, LSM_SETID_RES); if (retval) return retval; if (!capable(CAP_SETUID)) { if ((ruid != (uid_t) -1) && (ruid != current->uid) && (ruid != current->euid) && (ruid != current->suid)) return -EPERM; if ((euid != (uid_t) -1) && (euid != current->uid) && (euid != current->euid) && (euid != current->suid)) return -EPERM; if ((suid != (uid_t) -1) && (suid != current->uid) && (suid != current->euid) && (suid != current->suid)) return -EPERM; } if (ruid != (uid_t) -1) { if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0) return -EAGAIN; } if (euid != (uid_t) -1) { if (euid != current->euid) { current->mm->dumpable = 0; wmb(); } current->euid = euid; } current->fsuid = current->euid; if (suid != (uid_t) -1) current->suid = suid; return security_ops->task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES); } asmlinkage long sys_getresuid(uid_t *ruid, uid_t *euid, uid_t *suid) { int retval; if (!(retval = put_user(current->uid, ruid)) && !(retval = put_user(current->euid, euid))) retval = put_user(current->suid, suid); return retval; } /* * Same as above, but for rgid, egid, sgid. */ asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) { int retval; retval = security_ops->task_setgid(rgid, egid, sgid, LSM_SETID_RES); if (retval) return retval; if (!capable(CAP_SETGID)) { if ((rgid != (gid_t) -1) && (rgid != current->gid) && (rgid != current->egid) && (rgid != current->sgid)) return -EPERM; if ((egid != (gid_t) -1) && (egid != current->gid) && (egid != current->egid) && (egid != current->sgid)) return -EPERM; if ((sgid != (gid_t) -1) && (sgid != current->gid) && (sgid != current->egid) && (sgid != current->sgid)) return -EPERM; } if (egid != (gid_t) -1) { if (egid != current->egid) { current->mm->dumpable = 0; wmb(); } current->egid = egid; } current->fsgid = current->egid; if (rgid != (gid_t) -1) current->gid = rgid; if (sgid != (gid_t) -1) current->sgid = sgid; return 0; } asmlinkage long sys_getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid) { int retval; if (!(retval = put_user(current->gid, rgid)) && !(retval = put_user(current->egid, egid))) retval = put_user(current->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.. */ asmlinkage long sys_setfsuid(uid_t uid) { int old_fsuid; int retval; retval = security_ops->task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); if (retval) return retval; old_fsuid = current->fsuid; if (uid == current->uid || uid == current->euid || uid == current->suid || uid == current->fsuid || capable(CAP_SETUID)) { if (uid != old_fsuid) { current->mm->dumpable = 0; wmb(); } current->fsuid = uid; } retval = security_ops->task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); if (retval) return retval; return old_fsuid; } /* * Samma p� svenska.. */ asmlinkage long sys_setfsgid(gid_t gid) { int old_fsgid; int retval; retval = security_ops->task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS); if (retval) return retval; old_fsgid = current->fsgid; if (gid == current->gid || gid == current->egid || gid == current->sgid || gid == current->fsgid || capable(CAP_SETGID)) { if (gid != old_fsgid) { current->mm->dumpable = 0; wmb(); } current->fsgid = gid; } return old_fsgid; } asmlinkage long sys_times(struct tms * tbuf) { /* * In the SMP world we might just be unlucky and have one of * the times increment as we use it. Since the value is an * atomically safe type this is just fine. Conceptually its * as if the syscall took an instant longer to occur. */ if (tbuf) { struct tms tmp; tmp.tms_utime = jiffies_to_clock_t(current->utime); tmp.tms_stime = jiffies_to_clock_t(current->stime); tmp.tms_cutime = jiffies_to_clock_t(current->cutime); tmp.tms_cstime = jiffies_to_clock_t(current->cstime); if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) return -EFAULT; } return jiffies_to_clock_t(jiffies); } /* * 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 */ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) { struct task_struct *p; int err = -EINVAL; if (!pid) pid = current->pid; if (!pgid) pgid = pid; if (pgid < 0) return -EINVAL; /* 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_pid(pid); if (!p) goto out; err = -EINVAL; if (!thread_group_leader(p)) goto out; if (p->parent == current || p->real_parent == current) { err = -EPERM; if (p->session != current->session) goto out; err = -EACCES; if (p->did_exec) goto out; } else if (p != current) goto out; err = -EPERM; if (p->leader) goto out; if (pgid != pid) { struct task_struct *p; struct pid *pid; struct list_head *l; for_each_task_pid(pgid, PIDTYPE_PGID, p, l, pid) if (p->session == current->session) goto ok_pgid; goto out; } ok_pgid: if (p->pgrp != pgid) { detach_pid(p, PIDTYPE_PGID); p->pgrp = pgid; attach_pid(p, PIDTYPE_PGID, pgid); } err = 0; out: /* All paths lead to here, thus we are safe. -DaveM */ write_unlock_irq(&tasklist_lock); return err; } asmlinkage long sys_getpgid(pid_t pid) { if (!pid) { return current->pgrp; } else { int retval; struct task_struct *p; read_lock(&tasklist_lock); p = find_task_by_pid(pid); retval = -ESRCH; if (p) { retval = security_ops->task_getpgid(p); if (!retval) retval = p->pgrp; } read_unlock(&tasklist_lock); return retval; } } asmlinkage long sys_getpgrp(void) { /* SMP - assuming writes are word atomic this is fine */ return current->pgrp; } asmlinkage long sys_getsid(pid_t pid) { if (!pid) { return current->session; } else { int retval; struct task_struct *p; read_lock(&tasklist_lock); p = find_task_by_pid(pid); retval = -ESRCH; if(p) { retval = security_ops->task_getsid(p); if (!retval) retval = p->session; } read_unlock(&tasklist_lock); return retval; } } asmlinkage long sys_setsid(void) { struct pid *pid; int err = -EPERM; if (!thread_group_leader(current)) return -EINVAL; write_lock_irq(&tasklist_lock); pid = find_pid(PIDTYPE_PGID, current->pid); if (pid) goto out; current->leader = 1; if (current->session != current->pid) { detach_pid(current, PIDTYPE_SID); current->session = current->pid; attach_pid(current, PIDTYPE_SID, current->pid); } if (current->pgrp != current->pid) { detach_pid(current, PIDTYPE_PGID); current->pgrp = current->pid; attach_pid(current, PIDTYPE_PGID, current->pid); } current->tty = NULL; current->tty_old_pgrp = 0; err = current->pgrp; out: write_unlock_irq(&tasklist_lock); return err; } /* * Supplementary group IDs */ asmlinkage long sys_getgroups(int gidsetsize, gid_t *grouplist) { int i; /* * SMP: Nobody else can change our grouplist. Thus we are * safe. */ if (gidsetsize < 0) return -EINVAL; i = current->ngroups; if (gidsetsize) { if (i > gidsetsize) return -EINVAL; if (copy_to_user(grouplist, current->groups, sizeof(gid_t)*i)) return -EFAULT; } return i; } /* * SMP: Our groups are not shared. We can copy to/from them safely * without another task interfering. */ asmlinkage long sys_setgroups(int gidsetsize, gid_t *grouplist) { gid_t groups[NGROUPS]; int retval; if (!capable(CAP_SETGID)) return -EPERM; if ((unsigned) gidsetsize > NGROUPS) return -EINVAL; if(copy_from_user(groups, grouplist, gidsetsize * sizeof(gid_t))) return -EFAULT; retval = security_ops->task_setgroups(gidsetsize, groups); if (retval) return retval; memcpy(current->groups, groups, gidsetsize * sizeof(gid_t)); current->ngroups = gidsetsize; return 0; } static int supplemental_group_member(gid_t grp) { int i = current->ngroups; if (i) { gid_t *groups = current->groups; do { if (*groups == grp) return 1; groups++; i--; } while (i); } return 0; } /* * Check whether we're fsgid/egid or in the supplemental group.. */ int in_group_p(gid_t grp) { int retval = 1; if (grp != current->fsgid) retval = supplemental_group_member(grp); return retval; } int in_egroup_p(gid_t grp) { int retval = 1; if (grp != current->egid) retval = supplemental_group_member(grp); return retval; } DECLARE_RWSEM(uts_sem); asmlinkage long sys_newuname(struct new_utsname * name) { int errno = 0; down_read(&uts_sem); if (copy_to_user(name,&system_utsname,sizeof *name)) errno = -EFAULT; up_read(&uts_sem); return errno; } asmlinkage long sys_sethostname(char *name, int len) { int errno; 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(system_utsname.nodename, name, len)) { system_utsname.nodename[len] = 0; errno = 0; } up_write(&uts_sem); return errno; } asmlinkage long sys_gethostname(char *name, int len) { int i, errno; if (len < 0) return -EINVAL; down_read(&uts_sem); i = 1 + strlen(system_utsname.nodename); if (i > len) i = len; errno = 0; if (copy_to_user(name, system_utsname.nodename, i)) errno = -EFAULT; up_read(&uts_sem); return errno; } /* * Only setdomainname; getdomainname can be implemented by calling * uname() */ asmlinkage long sys_setdomainname(char *name, int len) { int errno; 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(system_utsname.domainname, name, len)) { errno = 0; system_utsname.domainname[len] = 0; } up_write(&uts_sem); return errno; } asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit *rlim) { if (resource >= RLIM_NLIMITS) return -EINVAL; else return copy_to_user(rlim, current->rlim + resource, sizeof(*rlim)) ? -EFAULT : 0; } #if !defined(__ia64__) /* * Back compatibility for getrlimit. Needed for some apps. */ asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit *rlim) { struct rlimit x; if (resource >= RLIM_NLIMITS) return -EINVAL; memcpy(&x, current->rlim + resource, sizeof(*rlim)); 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 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit *rlim) { struct rlimit new_rlim, *old_rlim; int retval; if (resource >= RLIM_NLIMITS) return -EINVAL; if(copy_from_user(&new_rlim, rlim, sizeof(*rlim))) return -EFAULT; old_rlim = current->rlim + resource; if (((new_rlim.rlim_cur > old_rlim->rlim_max) || (new_rlim.rlim_max > old_rlim->rlim_max)) && !capable(CAP_SYS_RESOURCE)) return -EPERM; if (resource == RLIMIT_NOFILE) { if (new_rlim.rlim_cur > NR_OPEN || new_rlim.rlim_max > NR_OPEN) return -EPERM; } retval = security_ops->task_setrlimit(resource, &new_rlim); if (retval) return retval; *old_rlim = new_rlim; return 0; } /* * 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). * * This is SMP safe. Either we are called from sys_getrusage on ourselves * below (we know we aren't going to exit/disappear and only we change our * rusage counters), or we are called from wait4() on a process which is * either stopped or zombied. In the zombied case the task won't get * reaped till shortly after the call to getrusage(), in both cases the * task being examined is in a frozen state so the counters won't change. * * FIXME! Get the fault counts properly! */ int getrusage(struct task_struct *p, int who, struct rusage *ru) { struct rusage r; memset((char *) &r, 0, sizeof(r)); switch (who) { case RUSAGE_SELF: jiffies_to_timeval(p->utime, &r.ru_utime); jiffies_to_timeval(p->stime, &r.ru_stime); r.ru_minflt = p->min_flt; r.ru_majflt = p->maj_flt; r.ru_nswap = p->nswap; break; case RUSAGE_CHILDREN: jiffies_to_timeval(p->cutime, &r.ru_utime); jiffies_to_timeval(p->cstime, &r.ru_stime); r.ru_minflt = p->cmin_flt; r.ru_majflt = p->cmaj_flt; r.ru_nswap = p->cnswap; break; default: jiffies_to_timeval(p->utime + p->cutime, &r.ru_utime); jiffies_to_timeval(p->stime + p->cstime, &r.ru_stime); r.ru_minflt = p->min_flt + p->cmin_flt; r.ru_majflt = p->maj_flt + p->cmaj_flt; r.ru_nswap = p->nswap + p->cnswap; break; } return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; } asmlinkage long sys_getrusage(int who, struct rusage *ru) { if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN) return -EINVAL; return getrusage(current, who, ru); } asmlinkage long sys_umask(int mask) { mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); return mask; } asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { int error = 0; int sig; error = security_ops->task_prctl(option, arg2, arg3, arg4, arg5); if (error) return error; switch (option) { case PR_SET_PDEATHSIG: sig = arg2; if (sig < 0 || sig > _NSIG) { error = -EINVAL; break; } current->pdeath_signal = sig; break; case PR_GET_PDEATHSIG: error = put_user(current->pdeath_signal, (int *)arg2); break; case PR_GET_DUMPABLE: if (current->mm->dumpable) error = 1; break; case PR_SET_DUMPABLE: if (arg2 != 0 && arg2 != 1) { error = -EINVAL; break; } current->mm->dumpable = arg2; break; case PR_SET_UNALIGN: error = SET_UNALIGN_CTL(current, arg2); break; case PR_GET_UNALIGN: error = GET_UNALIGN_CTL(current, arg2); break; case PR_SET_FPEMU: error = SET_FPEMU_CTL(current, arg2); break; case PR_GET_FPEMU: error = GET_FPEMU_CTL(current, arg2); break; case PR_SET_FPEXC: error = SET_FPEXC_CTL(current, arg2); break; case PR_GET_FPEXC: error = GET_FPEXC_CTL(current, arg2); break; case PR_GET_KEEPCAPS: if (current->keep_capabilities) error = 1; break; case PR_SET_KEEPCAPS: if (arg2 != 0 && arg2 != 1) { error = -EINVAL; break; } current->keep_capabilities = arg2; break; default: error = -EINVAL; break; } return error; } EXPORT_SYMBOL(notifier_chain_register); EXPORT_SYMBOL(notifier_chain_unregister); EXPORT_SYMBOL(notifier_call_chain); EXPORT_SYMBOL(register_reboot_notifier); EXPORT_SYMBOL(unregister_reboot_notifier); EXPORT_SYMBOL(in_group_p); EXPORT_SYMBOL(in_egroup_p);