| /* |
| * linux/kernel/sys.c |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| */ |
| |
| #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/highuid.h> |
| #include <linux/fs.h> |
| #include <linux/resource.h> |
| #include <linux/kernel.h> |
| #include <linux/kexec.h> |
| #include <linux/workqueue.h> |
| #include <linux/capability.h> |
| #include <linux/device.h> |
| #include <linux/key.h> |
| #include <linux/times.h> |
| #include <linux/posix-timers.h> |
| #include <linux/security.h> |
| #include <linux/dcookies.h> |
| #include <linux/suspend.h> |
| #include <linux/tty.h> |
| #include <linux/signal.h> |
| #include <linux/cn_proc.h> |
| #include <linux/getcpu.h> |
| #include <linux/task_io_accounting_ops.h> |
| #include <linux/seccomp.h> |
| #include <linux/cpu.h> |
| |
| #include <linux/compat.h> |
| #include <linux/syscalls.h> |
| #include <linux/kprobes.h> |
| #include <linux/user_namespace.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 |
| #ifndef GET_ENDIAN |
| # define GET_ENDIAN(a,b) (-EINVAL) |
| #endif |
| #ifndef SET_ENDIAN |
| # define SET_ENDIAN(a,b) (-EINVAL) |
| #endif |
| #ifndef GET_TSC_CTL |
| # define GET_TSC_CTL(a) (-EINVAL) |
| #endif |
| #ifndef SET_TSC_CTL |
| # define SET_TSC_CTL(a) (-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; |
| |
| #ifdef CONFIG_UID16 |
| EXPORT_SYMBOL(overflowuid); |
| EXPORT_SYMBOL(overflowgid); |
| #endif |
| |
| /* |
| * 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; |
| |
| EXPORT_SYMBOL(fs_overflowuid); |
| EXPORT_SYMBOL(fs_overflowgid); |
| |
| /* |
| * this indicates whether you can reboot with ctrl-alt-del: the default is yes |
| */ |
| |
| int C_A_D = 1; |
| struct pid *cad_pid; |
| EXPORT_SYMBOL(cad_pid); |
| |
| /* |
| * If set, this is used for preparing the system to power off. |
| */ |
| |
| void (*pm_power_off_prepare)(void); |
| |
| static int set_one_prio(struct task_struct *p, int niceval, int error) |
| { |
| int no_nice; |
| |
| if (p->uid != current->euid && |
| p->euid != current->euid && !capable(CAP_SYS_NICE)) { |
| error = -EPERM; |
| goto out; |
| } |
| if (niceval < task_nice(p) && !can_nice(p, niceval)) { |
| error = -EACCES; |
| goto out; |
| } |
| no_nice = security_task_setnice(p, niceval); |
| if (no_nice) { |
| error = no_nice; |
| goto out; |
| } |
| if (error == -ESRCH) |
| error = 0; |
| 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; |
| int error = -EINVAL; |
| struct pid *pgrp; |
| |
| if (which > PRIO_USER || which < PRIO_PROCESS) |
| 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) |
| p = find_task_by_vpid(who); |
| else |
| p = current; |
| if (p) |
| error = set_one_prio(p, niceval, error); |
| break; |
| case PRIO_PGRP: |
| if (who) |
| pgrp = find_vpid(who); |
| else |
| pgrp = task_pgrp(current); |
| do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
| error = set_one_prio(p, niceval, error); |
| } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
| break; |
| case PRIO_USER: |
| user = current->user; |
| if (!who) |
| who = current->uid; |
| else |
| if ((who != current->uid) && !(user = find_user(who))) |
| goto out_unlock; /* No processes for this user */ |
| |
| do_each_thread(g, p) |
| if (p->uid == who) |
| error = set_one_prio(p, niceval, error); |
| while_each_thread(g, p); |
| if (who != current->uid) |
| free_uid(user); /* For find_user() */ |
| 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 user_struct *user; |
| long niceval, retval = -ESRCH; |
| struct pid *pgrp; |
| |
| if (which > PRIO_USER || which < PRIO_PROCESS) |
| return -EINVAL; |
| |
| read_lock(&tasklist_lock); |
| switch (which) { |
| case PRIO_PROCESS: |
| if (who) |
| p = find_task_by_vpid(who); |
| else |
| p = current; |
| if (p) { |
| niceval = 20 - task_nice(p); |
| if (niceval > retval) |
| retval = niceval; |
| } |
| break; |
| case PRIO_PGRP: |
| if (who) |
| pgrp = find_vpid(who); |
| else |
| pgrp = task_pgrp(current); |
| do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
| niceval = 20 - task_nice(p); |
| if (niceval > retval) |
| retval = niceval; |
| } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
| break; |
| case PRIO_USER: |
| user = current->user; |
| if (!who) |
| who = current->uid; |
| else |
| if ((who != current->uid) && !(user = find_user(who))) |
| goto out_unlock; /* No processes for this user */ |
| |
| do_each_thread(g, p) |
| if (p->uid == who) { |
| niceval = 20 - task_nice(p); |
| if (niceval > retval) |
| retval = niceval; |
| } |
| while_each_thread(g, p); |
| if (who != current->uid) |
| free_uid(user); /* for find_user() */ |
| break; |
| } |
| out_unlock: |
| read_unlock(&tasklist_lock); |
| |
| return retval; |
| } |
| |
| /** |
| * emergency_restart - reboot the system |
| * |
| * Without shutting down any hardware or taking any locks |
| * reboot the system. This is called when we know we are in |
| * trouble so this is our best effort to reboot. This is |
| * safe to call in interrupt context. |
| */ |
| void emergency_restart(void) |
| { |
| machine_emergency_restart(); |
| } |
| EXPORT_SYMBOL_GPL(emergency_restart); |
| |
| static void kernel_restart_prepare(char *cmd) |
| { |
| blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); |
| system_state = SYSTEM_RESTART; |
| device_shutdown(); |
| sysdev_shutdown(); |
| } |
| |
| /** |
| * kernel_restart - reboot the system |
| * @cmd: pointer to buffer containing command to execute for restart |
| * or %NULL |
| * |
| * Shutdown everything and perform a clean reboot. |
| * This is not safe to call in interrupt context. |
| */ |
| void kernel_restart(char *cmd) |
| { |
| kernel_restart_prepare(cmd); |
| if (!cmd) |
| printk(KERN_EMERG "Restarting system.\n"); |
| else |
| printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); |
| machine_restart(cmd); |
| } |
| EXPORT_SYMBOL_GPL(kernel_restart); |
| |
| /** |
| * kernel_kexec - reboot the system |
| * |
| * Move into place and start executing a preloaded standalone |
| * executable. If nothing was preloaded return an error. |
| */ |
| static void kernel_kexec(void) |
| { |
| #ifdef CONFIG_KEXEC |
| struct kimage *image; |
| image = xchg(&kexec_image, NULL); |
| if (!image) |
| return; |
| kernel_restart_prepare(NULL); |
| printk(KERN_EMERG "Starting new kernel\n"); |
| machine_shutdown(); |
| machine_kexec(image); |
| #endif |
| } |
| |
| static void kernel_shutdown_prepare(enum system_states state) |
| { |
| blocking_notifier_call_chain(&reboot_notifier_list, |
| (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); |
| system_state = state; |
| device_shutdown(); |
| } |
| /** |
| * kernel_halt - halt the system |
| * |
| * Shutdown everything and perform a clean system halt. |
| */ |
| void kernel_halt(void) |
| { |
| kernel_shutdown_prepare(SYSTEM_HALT); |
| sysdev_shutdown(); |
| printk(KERN_EMERG "System halted.\n"); |
| machine_halt(); |
| } |
| |
| EXPORT_SYMBOL_GPL(kernel_halt); |
| |
| /** |
| * kernel_power_off - power_off the system |
| * |
| * Shutdown everything and perform a clean system power_off. |
| */ |
| void kernel_power_off(void) |
| { |
| kernel_shutdown_prepare(SYSTEM_POWER_OFF); |
| if (pm_power_off_prepare) |
| pm_power_off_prepare(); |
| disable_nonboot_cpus(); |
| sysdev_shutdown(); |
| printk(KERN_EMERG "Power down.\n"); |
| machine_power_off(); |
| } |
| EXPORT_SYMBOL_GPL(kernel_power_off); |
| /* |
| * 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 __user * 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 && |
| magic2 != LINUX_REBOOT_MAGIC2C)) |
| return -EINVAL; |
| |
| /* Instead of trying to make the power_off code look like |
| * halt when pm_power_off is not set do it the easy way. |
| */ |
| if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) |
| cmd = LINUX_REBOOT_CMD_HALT; |
| |
| lock_kernel(); |
| switch (cmd) { |
| case LINUX_REBOOT_CMD_RESTART: |
| kernel_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: |
| kernel_halt(); |
| unlock_kernel(); |
| do_exit(0); |
| break; |
| |
| case LINUX_REBOOT_CMD_POWER_OFF: |
| kernel_power_off(); |
| unlock_kernel(); |
| do_exit(0); |
| break; |
| |
| case LINUX_REBOOT_CMD_RESTART2: |
| if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { |
| unlock_kernel(); |
| return -EFAULT; |
| } |
| buffer[sizeof(buffer) - 1] = '\0'; |
| |
| kernel_restart(buffer); |
| break; |
| |
| case LINUX_REBOOT_CMD_KEXEC: |
| kernel_kexec(); |
| unlock_kernel(); |
| return -EINVAL; |
| |
| #ifdef CONFIG_HIBERNATION |
| case LINUX_REBOOT_CMD_SW_SUSPEND: |
| { |
| int ret = hibernate(); |
| unlock_kernel(); |
| return ret; |
| } |
| #endif |
| |
| default: |
| unlock_kernel(); |
| return -EINVAL; |
| } |
| unlock_kernel(); |
| return 0; |
| } |
| |
| static void deferred_cad(struct work_struct *dummy) |
| { |
| kernel_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 DECLARE_WORK(cad_work, deferred_cad); |
| |
| if (C_A_D) |
| schedule_work(&cad_work); |
| else |
| kill_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_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) { |
| set_dumpable(current->mm, suid_dumpable); |
| smp_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; |
| key_fsgid_changed(current); |
| proc_id_connector(current, PROC_EVENT_GID); |
| 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_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID); |
| if (retval) |
| return retval; |
| |
| if (capable(CAP_SETGID)) { |
| if (old_egid != gid) { |
| set_dumpable(current->mm, suid_dumpable); |
| smp_wmb(); |
| } |
| current->gid = current->egid = current->sgid = current->fsgid = gid; |
| } else if ((gid == current->gid) || (gid == current->sgid)) { |
| if (old_egid != gid) { |
| set_dumpable(current->mm, suid_dumpable); |
| smp_wmb(); |
| } |
| current->egid = current->fsgid = gid; |
| } |
| else |
| return -EPERM; |
| |
| key_fsgid_changed(current); |
| proc_id_connector(current, PROC_EVENT_GID); |
| return 0; |
| } |
| |
| static int set_user(uid_t new_ruid, int dumpclear) |
| { |
| struct user_struct *new_user; |
| |
| new_user = alloc_uid(current->nsproxy->user_ns, new_ruid); |
| if (!new_user) |
| return -EAGAIN; |
| |
| if (atomic_read(&new_user->processes) >= |
| current->signal->rlim[RLIMIT_NPROC].rlim_cur && |
| new_user != current->nsproxy->user_ns->root_user) { |
| free_uid(new_user); |
| return -EAGAIN; |
| } |
| |
| switch_uid(new_user); |
| |
| if (dumpclear) { |
| set_dumpable(current->mm, suid_dumpable); |
| smp_wmb(); |
| } |
| current->uid = new_ruid; |
| 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_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) { |
| set_dumpable(current->mm, suid_dumpable); |
| smp_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; |
| |
| key_fsuid_changed(current); |
| proc_id_connector(current, PROC_EVENT_UID); |
| |
| return security_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_suid; |
| int retval; |
| |
| retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID); |
| if (retval) |
| return retval; |
| |
| old_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) { |
| set_dumpable(current->mm, suid_dumpable); |
| smp_wmb(); |
| } |
| current->fsuid = current->euid = uid; |
| current->suid = new_suid; |
| |
| key_fsuid_changed(current); |
| proc_id_connector(current, PROC_EVENT_UID); |
| |
| return security_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_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) { |
| set_dumpable(current->mm, suid_dumpable); |
| smp_wmb(); |
| } |
| current->euid = euid; |
| } |
| current->fsuid = current->euid; |
| if (suid != (uid_t) -1) |
| current->suid = suid; |
| |
| key_fsuid_changed(current); |
| proc_id_connector(current, PROC_EVENT_UID); |
| |
| return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES); |
| } |
| |
| asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *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_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) { |
| set_dumpable(current->mm, suid_dumpable); |
| smp_wmb(); |
| } |
| current->egid = egid; |
| } |
| current->fsgid = current->egid; |
| if (rgid != (gid_t) -1) |
| current->gid = rgid; |
| if (sgid != (gid_t) -1) |
| current->sgid = sgid; |
| |
| key_fsgid_changed(current); |
| proc_id_connector(current, PROC_EVENT_GID); |
| return 0; |
| } |
| |
| asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *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; |
| |
| old_fsuid = current->fsuid; |
| if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS)) |
| return old_fsuid; |
| |
| if (uid == current->uid || uid == current->euid || |
| uid == current->suid || uid == current->fsuid || |
| capable(CAP_SETUID)) { |
| if (uid != old_fsuid) { |
| set_dumpable(current->mm, suid_dumpable); |
| smp_wmb(); |
| } |
| current->fsuid = uid; |
| } |
| |
| key_fsuid_changed(current); |
| proc_id_connector(current, PROC_EVENT_UID); |
| |
| security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); |
| |
| return old_fsuid; |
| } |
| |
| /* |
| * Samma på svenska.. |
| */ |
| asmlinkage long sys_setfsgid(gid_t gid) |
| { |
| int old_fsgid; |
| |
| old_fsgid = current->fsgid; |
| if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS)) |
| return old_fsgid; |
| |
| if (gid == current->gid || gid == current->egid || |
| gid == current->sgid || gid == current->fsgid || |
| capable(CAP_SETGID)) { |
| if (gid != old_fsgid) { |
| set_dumpable(current->mm, suid_dumpable); |
| smp_wmb(); |
| } |
| current->fsgid = gid; |
| key_fsgid_changed(current); |
| proc_id_connector(current, PROC_EVENT_GID); |
| } |
| return old_fsgid; |
| } |
| |
| asmlinkage long sys_times(struct tms __user * 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; |
| struct task_struct *tsk = current; |
| struct task_struct *t; |
| cputime_t utime, stime, cutime, cstime; |
| |
| spin_lock_irq(&tsk->sighand->siglock); |
| utime = tsk->signal->utime; |
| stime = tsk->signal->stime; |
| t = tsk; |
| do { |
| utime = cputime_add(utime, t->utime); |
| stime = cputime_add(stime, t->stime); |
| t = next_thread(t); |
| } while (t != tsk); |
| |
| cutime = tsk->signal->cutime; |
| cstime = tsk->signal->cstime; |
| spin_unlock_irq(&tsk->sighand->siglock); |
| |
| tmp.tms_utime = cputime_to_clock_t(utime); |
| tmp.tms_stime = cputime_to_clock_t(stime); |
| tmp.tms_cutime = cputime_to_clock_t(cutime); |
| tmp.tms_cstime = cputime_to_clock_t(cstime); |
| if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) |
| return -EFAULT; |
| } |
| 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 |
| */ |
| asmlinkage long sys_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; |
| |
| /* 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) { |
| detach_pid(p, PIDTYPE_PGID); |
| attach_pid(p, PIDTYPE_PGID, pgrp); |
| set_task_pgrp(p, pid_nr(pgrp)); |
| } |
| |
| 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 task_pgrp_vnr(current); |
| else { |
| int retval; |
| struct task_struct *p; |
| |
| read_lock(&tasklist_lock); |
| p = find_task_by_vpid(pid); |
| retval = -ESRCH; |
| if (p) { |
| retval = security_task_getpgid(p); |
| if (!retval) |
| retval = task_pgrp_vnr(p); |
| } |
| read_unlock(&tasklist_lock); |
| return retval; |
| } |
| } |
| |
| #ifdef __ARCH_WANT_SYS_GETPGRP |
| |
| asmlinkage long sys_getpgrp(void) |
| { |
| /* SMP - assuming writes are word atomic this is fine */ |
| return task_pgrp_vnr(current); |
| } |
| |
| #endif |
| |
| asmlinkage long sys_getsid(pid_t pid) |
| { |
| if (!pid) |
| return task_session_vnr(current); |
| else { |
| int retval; |
| struct task_struct *p; |
| |
| rcu_read_lock(); |
| p = find_task_by_vpid(pid); |
| retval = -ESRCH; |
| if (p) { |
| retval = security_task_getsid(p); |
| if (!retval) |
| retval = task_session_vnr(p); |
| } |
| rcu_read_unlock(); |
| return retval; |
| } |
| } |
| |
| asmlinkage long sys_setsid(void) |
| { |
| 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); |
| |
| spin_lock(&group_leader->sighand->siglock); |
| group_leader->signal->tty = NULL; |
| spin_unlock(&group_leader->sighand->siglock); |
| |
| err = session; |
| out: |
| write_unlock_irq(&tasklist_lock); |
| return err; |
| } |
| |
| /* |
| * Supplementary group IDs |
| */ |
| |
| /* init to 2 - one for init_task, one to ensure it is never freed */ |
| struct group_info init_groups = { .usage = ATOMIC_INIT(2) }; |
| |
| struct group_info *groups_alloc(int gidsetsize) |
| { |
| struct group_info *group_info; |
| int nblocks; |
| int i; |
| |
| nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK; |
| /* Make sure we always allocate at least one indirect block pointer */ |
| nblocks = nblocks ? : 1; |
| group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER); |
| if (!group_info) |
| return NULL; |
| group_info->ngroups = gidsetsize; |
| group_info->nblocks = nblocks; |
| atomic_set(&group_info->usage, 1); |
| |
| if (gidsetsize <= NGROUPS_SMALL) |
| group_info->blocks[0] = group_info->small_block; |
| else { |
| for (i = 0; i < nblocks; i++) { |
| gid_t *b; |
| b = (void *)__get_free_page(GFP_USER); |
| if (!b) |
| goto out_undo_partial_alloc; |
| group_info->blocks[i] = b; |
| } |
| } |
| return group_info; |
| |
| out_undo_partial_alloc: |
| while (--i >= 0) { |
| free_page((unsigned long)group_info->blocks[i]); |
| } |
| kfree(group_info); |
| return NULL; |
| } |
| |
| EXPORT_SYMBOL(groups_alloc); |
| |
| void groups_free(struct group_info *group_info) |
| { |
| if (group_info->blocks[0] != group_info->small_block) { |
| int i; |
| for (i = 0; i < group_info->nblocks; i++) |
| free_page((unsigned long)group_info->blocks[i]); |
| } |
| kfree(group_info); |
| } |
| |
| EXPORT_SYMBOL(groups_free); |
| |
| /* export the group_info to a user-space array */ |
| static int groups_to_user(gid_t __user *grouplist, |
| struct group_info *group_info) |
| { |
| int i; |
| unsigned int count = group_info->ngroups; |
| |
| for (i = 0; i < group_info->nblocks; i++) { |
| unsigned int cp_count = min(NGROUPS_PER_BLOCK, count); |
| unsigned int len = cp_count * sizeof(*grouplist); |
| |
| if (copy_to_user(grouplist, group_info->blocks[i], len)) |
| return -EFAULT; |
| |
| grouplist += NGROUPS_PER_BLOCK; |
| count -= cp_count; |
| } |
| return 0; |
| } |
| |
| /* fill a group_info from a user-space array - it must be allocated already */ |
| static int groups_from_user(struct group_info *group_info, |
| gid_t __user *grouplist) |
| { |
| int i; |
| unsigned int count = group_info->ngroups; |
| |
| for (i = 0; i < group_info->nblocks; i++) { |
| unsigned int cp_count = min(NGROUPS_PER_BLOCK, count); |
| unsigned int len = cp_count * sizeof(*grouplist); |
| |
| if (copy_from_user(group_info->blocks[i], grouplist, len)) |
| return -EFAULT; |
| |
| grouplist += NGROUPS_PER_BLOCK; |
| count -= cp_count; |
| } |
| return 0; |
| } |
| |
| /* a simple Shell sort */ |
| static void groups_sort(struct group_info *group_info) |
| { |
| int base, max, stride; |
| int gidsetsize = group_info->ngroups; |
| |
| for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1) |
| ; /* nothing */ |
| stride /= 3; |
| |
| while (stride) { |
| max = gidsetsize - stride; |
| for (base = 0; base < max; base++) { |
| int left = base; |
| int right = left + stride; |
| gid_t tmp = GROUP_AT(group_info, right); |
| |
| while (left >= 0 && GROUP_AT(group_info, left) > tmp) { |
| GROUP_AT(group_info, right) = |
| GROUP_AT(group_info, left); |
| right = left; |
| left -= stride; |
| } |
| GROUP_AT(group_info, right) = tmp; |
| } |
| stride /= 3; |
| } |
| } |
| |
| /* a simple bsearch */ |
| int groups_search(struct group_info *group_info, gid_t grp) |
| { |
| unsigned int left, right; |
| |
| if (!group_info) |
| return 0; |
| |
| left = 0; |
| right = group_info->ngroups; |
| while (left < right) { |
| unsigned int mid = (left+right)/2; |
| int cmp = grp - GROUP_AT(group_info, mid); |
| if (cmp > 0) |
| left = mid + 1; |
| else if (cmp < 0) |
| right = mid; |
| else |
| return 1; |
| } |
| return 0; |
| } |
| |
| /* validate and set current->group_info */ |
| int set_current_groups(struct group_info *group_info) |
| { |
| int retval; |
| struct group_info *old_info; |
| |
| retval = security_task_setgroups(group_info); |
| if (retval) |
| return retval; |
| |
| groups_sort(group_info); |
| get_group_info(group_info); |
| |
| task_lock(current); |
| old_info = current->group_info; |
| current->group_info = group_info; |
| task_unlock(current); |
| |
| put_group_info(old_info); |
| |
| return 0; |
| } |
| |
| EXPORT_SYMBOL(set_current_groups); |
| |
| asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist) |
| { |
| int i = 0; |
| |
| /* |
| * SMP: Nobody else can change our grouplist. Thus we are |
| * safe. |
| */ |
| |
| if (gidsetsize < 0) |
| return -EINVAL; |
| |
| /* no need to grab task_lock here; it cannot change */ |
| i = current->group_info->ngroups; |
| if (gidsetsize) { |
| if (i > gidsetsize) { |
| i = -EINVAL; |
| goto out; |
| } |
| if (groups_to_user(grouplist, current->group_info)) { |
| i = -EFAULT; |
| goto out; |
| } |
| } |
| out: |
| return i; |
| } |
| |
| /* |
| * SMP: Our groups are copy-on-write. We can set them safely |
| * without another task interfering. |
| */ |
| |
| asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist) |
| { |
| struct group_info *group_info; |
| int retval; |
| |
| if (!capable(CAP_SETGID)) |
| return -EPERM; |
| if ((unsigned)gidsetsize > NGROUPS_MAX) |
| return -EINVAL; |
| |
| group_info = groups_alloc(gidsetsize); |
| if (!group_info) |
| return -ENOMEM; |
| retval = groups_from_user(group_info, grouplist); |
| if (retval) { |
| put_group_info(group_info); |
| return retval; |
| } |
| |
| retval = set_current_groups(group_info); |
| put_group_info(group_info); |
| |
| return retval; |
| } |
| |
| /* |
| * 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 = groups_search(current->group_info, grp); |
| return retval; |
| } |
| |
| EXPORT_SYMBOL(in_group_p); |
| |
| int in_egroup_p(gid_t grp) |
| { |
| int retval = 1; |
| if (grp != current->egid) |
| retval = groups_search(current->group_info, grp); |
| return retval; |
| } |
| |
| EXPORT_SYMBOL(in_egroup_p); |
| |
| DECLARE_RWSEM(uts_sem); |
| |
| EXPORT_SYMBOL(uts_sem); |
| |
| asmlinkage long sys_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); |
| return errno; |
| } |
| |
| asmlinkage long sys_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)) { |
| memcpy(utsname()->nodename, tmp, len); |
| utsname()->nodename[len] = 0; |
| errno = 0; |
| } |
| up_write(&uts_sem); |
| return errno; |
| } |
| |
| #ifdef __ARCH_WANT_SYS_GETHOSTNAME |
| |
| asmlinkage long sys_gethostname(char __user *name, int len) |
| { |
| int i, errno; |
| |
| if (len < 0) |
| return -EINVAL; |
| down_read(&uts_sem); |
| i = 1 + strlen(utsname()->nodename); |
| if (i > len) |
| i = len; |
| errno = 0; |
| if (copy_to_user(name, utsname()->nodename, i)) |
| errno = -EFAULT; |
| up_read(&uts_sem); |
| return errno; |
| } |
| |
| #endif |
| |
| /* |
| * Only setdomainname; getdomainname can be implemented by calling |
| * uname() |
| */ |
| asmlinkage long sys_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)) { |
| memcpy(utsname()->domainname, tmp, len); |
| utsname()->domainname[len] = 0; |
| errno = 0; |
| } |
| up_write(&uts_sem); |
| return errno; |
| } |
| |
| asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim) |
| { |
| if (resource >= RLIM_NLIMITS) |
| return -EINVAL; |
| else { |
| struct rlimit value; |
| task_lock(current->group_leader); |
| value = current->signal->rlim[resource]; |
| task_unlock(current->group_leader); |
| return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; |
| } |
| } |
| |
| #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT |
| |
| /* |
| * Back compatibility for getrlimit. Needed for some apps. |
| */ |
| |
| asmlinkage long sys_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 |
| |
| asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim) |
| { |
| struct rlimit new_rlim, *old_rlim; |
| unsigned long it_prof_secs; |
| int retval; |
| |
| if (resource >= RLIM_NLIMITS) |
| return -EINVAL; |
| if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) |
| return -EFAULT; |
| if (new_rlim.rlim_cur > new_rlim.rlim_max) |
| return -EINVAL; |
| old_rlim = current->signal->rlim + resource; |
| if ((new_rlim.rlim_max > old_rlim->rlim_max) && |
| !capable(CAP_SYS_RESOURCE)) |
| return -EPERM; |
| if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open) |
| return -EPERM; |
| |
| retval = security_task_setrlimit(resource, &new_rlim); |
| if (retval) |
| return retval; |
| |
| 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; |
| } |
| |
| task_lock(current->group_leader); |
| *old_rlim = new_rlim; |
| task_unlock(current->group_leader); |
| |
| if (resource != RLIMIT_CPU) |
| goto out; |
| |
| /* |
| * 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 (new_rlim.rlim_cur == RLIM_INFINITY) |
| goto out; |
| |
| it_prof_secs = cputime_to_secs(current->signal->it_prof_expires); |
| if (it_prof_secs == 0 || new_rlim.rlim_cur <= it_prof_secs) { |
| unsigned long rlim_cur = new_rlim.rlim_cur; |
| cputime_t cputime; |
| |
| cputime = secs_to_cputime(rlim_cur); |
| read_lock(&tasklist_lock); |
| spin_lock_irq(¤t->sighand->siglock); |
| set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL); |
| spin_unlock_irq(¤t->sighand->siglock); |
| read_unlock(&tasklist_lock); |
| } |
| out: |
| 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). |
| * |
| * 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, |
| cputime_t *utimep, cputime_t *stimep) |
| { |
| *utimep = cputime_add(*utimep, t->utime); |
| *stimep = cputime_add(*stimep, t->stime); |
| 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 utime, stime; |
| |
| memset((char *) r, 0, sizeof *r); |
| utime = stime = cputime_zero; |
| |
| if (who == RUSAGE_THREAD) { |
| accumulate_thread_rusage(p, r, &utime, &stime); |
| 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; |
| |
| if (who == RUSAGE_CHILDREN) |
| break; |
| |
| case RUSAGE_SELF: |
| utime = cputime_add(utime, p->signal->utime); |
| stime = cputime_add(stime, p->signal->stime); |
| 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; |
| t = p; |
| do { |
| accumulate_thread_rusage(t, r, &utime, &stime); |
| 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); |
| } |
| |
| 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; |
| } |
| |
| asmlinkage long sys_getrusage(int who, struct rusage __user *ru) |
| { |
| if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && |
| who != RUSAGE_THREAD) |
| 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) |
| { |
| long uninitialized_var(error); |
| |
| if (security_task_prctl(option, arg2, arg3, arg4, arg5, &error)) |
| return error; |
| |
| switch (option) { |
| case PR_SET_PDEATHSIG: |
| if (!valid_signal(arg2)) { |
| error = -EINVAL; |
| break; |
| } |
| current->pdeath_signal = arg2; |
| break; |
| case PR_GET_PDEATHSIG: |
| error = put_user(current->pdeath_signal, (int __user *)arg2); |
| break; |
| case PR_GET_DUMPABLE: |
| error = get_dumpable(current->mm); |
| break; |
| case PR_SET_DUMPABLE: |
| if (arg2 < 0 || arg2 > 1) { |
| error = -EINVAL; |
| break; |
| } |
| set_dumpable(current->mm, 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_TIMING: |
| error = PR_TIMING_STATISTICAL; |
| break; |
| case PR_SET_TIMING: |
| if (arg2 == PR_TIMING_STATISTICAL) |
| error = 0; |
| else |
| error = -EINVAL; |
| break; |
| |
| case PR_SET_NAME: { |
| struct task_struct *me = current; |
| unsigned char ncomm[sizeof(me->comm)]; |
| |
| ncomm[sizeof(me->comm)-1] = 0; |
| if (strncpy_from_user(ncomm, (char __user *)arg2, |
| sizeof(me->comm)-1) < 0) |
| return -EFAULT; |
| set_task_comm(me, ncomm); |
| return 0; |
| } |
| case PR_GET_NAME: { |
| struct task_struct *me = current; |
| unsigned char tcomm[sizeof(me->comm)]; |
| |
| get_task_comm(tcomm, me); |
| if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm))) |
| return -EFAULT; |
| return 0; |
| } |
| case PR_GET_ENDIAN: |
| error = GET_ENDIAN(current, arg2); |
| break; |
| case PR_SET_ENDIAN: |
| error = SET_ENDIAN(current, 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; |
| default: |
| error = -EINVAL; |
| break; |
| } |
| return error; |
| } |
| |
| asmlinkage long sys_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(char **argv, char **envp) |
| { |
| argv_free(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); |
| if (info == NULL) { |
| argv_free(argv); |
| goto out; |
| } |
| |
| call_usermodehelper_setcleanup(info, argv_cleanup); |
| |
| 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); |