diff options
Diffstat (limited to 'kernel/sys.c')
| -rw-r--r-- | kernel/sys.c | 202 |
1 files changed, 142 insertions, 60 deletions
diff --git a/kernel/sys.c b/kernel/sys.c index f006632c2ba..0bcaed6560a 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -16,6 +16,8 @@ #include <linux/init.h> #include <linux/highuid.h> #include <linux/fs.h> +#include <linux/kernel.h> +#include <linux/kexec.h> #include <linux/workqueue.h> #include <linux/device.h> #include <linux/key.h> @@ -359,6 +361,64 @@ out_unlock: return retval; } +void emergency_restart(void) +{ + machine_emergency_restart(); +} +EXPORT_SYMBOL_GPL(emergency_restart); + +void kernel_restart(char *cmd) +{ + notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); + system_state = SYSTEM_RESTART; + device_shutdown(); + if (!cmd) { + printk(KERN_EMERG "Restarting system.\n"); + } else { + printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); + } + printk(".\n"); + machine_restart(cmd); +} +EXPORT_SYMBOL_GPL(kernel_restart); + +void kernel_kexec(void) +{ +#ifdef CONFIG_KEXEC + struct kimage *image; + image = xchg(&kexec_image, 0); + if (!image) { + return; + } + notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL); + system_state = SYSTEM_RESTART; + device_shutdown(); + printk(KERN_EMERG "Starting new kernel\n"); + machine_shutdown(); + machine_kexec(image); +#endif +} +EXPORT_SYMBOL_GPL(kernel_kexec); + +void kernel_halt(void) +{ + notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL); + system_state = SYSTEM_HALT; + device_shutdown(); + printk(KERN_EMERG "System halted.\n"); + machine_halt(); +} +EXPORT_SYMBOL_GPL(kernel_halt); + +void kernel_power_off(void) +{ + notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL); + system_state = SYSTEM_POWER_OFF; + device_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, @@ -387,11 +447,7 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user lock_kernel(); switch (cmd) { case LINUX_REBOOT_CMD_RESTART: - notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL); - system_state = SYSTEM_RESTART; - device_shutdown(); - printk(KERN_EMERG "Restarting system.\n"); - machine_restart(NULL); + kernel_restart(NULL); break; case LINUX_REBOOT_CMD_CAD_ON: @@ -403,21 +459,13 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user break; case LINUX_REBOOT_CMD_HALT: - notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL); - system_state = SYSTEM_HALT; - device_shutdown(); - printk(KERN_EMERG "System halted.\n"); - machine_halt(); + kernel_halt(); unlock_kernel(); do_exit(0); break; case LINUX_REBOOT_CMD_POWER_OFF: - notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL); - system_state = SYSTEM_POWER_OFF; - device_shutdown(); - printk(KERN_EMERG "Power down.\n"); - machine_power_off(); + kernel_power_off(); unlock_kernel(); do_exit(0); break; @@ -429,13 +477,14 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user } buffer[sizeof(buffer) - 1] = '\0'; - notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer); - system_state = SYSTEM_RESTART; - device_shutdown(); - printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer); - machine_restart(buffer); + kernel_restart(buffer); break; + case LINUX_REBOOT_CMD_KEXEC: + kernel_kexec(); + unlock_kernel(); + return -EINVAL; + #ifdef CONFIG_SOFTWARE_SUSPEND case LINUX_REBOOT_CMD_SW_SUSPEND: { @@ -455,8 +504,7 @@ asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user static void deferred_cad(void *dummy) { - notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL); - machine_restart(NULL); + kernel_restart(NULL); } /* @@ -525,7 +573,7 @@ asmlinkage long sys_setregid(gid_t rgid, gid_t egid) } if (new_egid != old_egid) { - current->mm->dumpable = 0; + current->mm->dumpable = suid_dumpable; smp_wmb(); } if (rgid != (gid_t) -1 || @@ -556,7 +604,7 @@ asmlinkage long sys_setgid(gid_t gid) { if(old_egid != gid) { - current->mm->dumpable=0; + current->mm->dumpable = suid_dumpable; smp_wmb(); } current->gid = current->egid = current->sgid = current->fsgid = gid; @@ -565,7 +613,7 @@ asmlinkage long sys_setgid(gid_t gid) { if(old_egid != gid) { - current->mm->dumpable=0; + current->mm->dumpable = suid_dumpable; smp_wmb(); } current->egid = current->fsgid = gid; @@ -596,7 +644,7 @@ static int set_user(uid_t new_ruid, int dumpclear) if(dumpclear) { - current->mm->dumpable = 0; + current->mm->dumpable = suid_dumpable; smp_wmb(); } current->uid = new_ruid; @@ -653,7 +701,7 @@ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) if (new_euid != old_euid) { - current->mm->dumpable=0; + current->mm->dumpable = suid_dumpable; smp_wmb(); } current->fsuid = current->euid = new_euid; @@ -703,7 +751,7 @@ asmlinkage long sys_setuid(uid_t uid) if (old_euid != uid) { - current->mm->dumpable = 0; + current->mm->dumpable = suid_dumpable; smp_wmb(); } current->fsuid = current->euid = uid; @@ -748,7 +796,7 @@ asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) if (euid != (uid_t) -1) { if (euid != current->euid) { - current->mm->dumpable = 0; + current->mm->dumpable = suid_dumpable; smp_wmb(); } current->euid = euid; @@ -798,7 +846,7 @@ asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) if (egid != (gid_t) -1) { if (egid != current->egid) { - current->mm->dumpable = 0; + current->mm->dumpable = suid_dumpable; smp_wmb(); } current->egid = egid; @@ -845,7 +893,7 @@ asmlinkage long sys_setfsuid(uid_t uid) { if (uid != old_fsuid) { - current->mm->dumpable = 0; + current->mm->dumpable = suid_dumpable; smp_wmb(); } current->fsuid = uid; @@ -875,7 +923,7 @@ asmlinkage long sys_setfsgid(gid_t gid) { if (gid != old_fsgid) { - current->mm->dumpable = 0; + current->mm->dumpable = suid_dumpable; smp_wmb(); } current->fsgid = gid; @@ -894,35 +942,69 @@ asmlinkage long sys_times(struct tms __user * tbuf) */ if (tbuf) { struct tms tmp; - struct task_struct *tsk = current; - struct task_struct *t; cputime_t utime, stime, cutime, cstime; - read_lock(&tasklist_lock); - 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); - - /* - * While we have tasklist_lock read-locked, no dying thread - * can be updating current->signal->[us]time. Instead, - * we got their counts included in the live thread loop. - * However, another thread can come in right now and - * do a wait call that updates current->signal->c[us]time. - * To make sure we always see that pair updated atomically, - * we take the siglock around fetching them. - */ - spin_lock_irq(&tsk->sighand->siglock); - cutime = tsk->signal->cutime; - cstime = tsk->signal->cstime; - spin_unlock_irq(&tsk->sighand->siglock); - read_unlock(&tasklist_lock); +#ifdef CONFIG_SMP + if (thread_group_empty(current)) { + /* + * Single thread case without the use of any locks. + * + * We may race with release_task if two threads are + * executing. However, release task first adds up the + * counters (__exit_signal) before removing the task + * from the process tasklist (__unhash_process). + * __exit_signal also acquires and releases the + * siglock which results in the proper memory ordering + * so that the list modifications are always visible + * after the counters have been updated. + * + * If the counters have been updated by the second thread + * but the thread has not yet been removed from the list + * then the other branch will be executing which will + * block on tasklist_lock until the exit handling of the + * other task is finished. + * + * This also implies that the sighand->siglock cannot + * be held by another processor. So we can also + * skip acquiring that lock. + */ + utime = cputime_add(current->signal->utime, current->utime); + stime = cputime_add(current->signal->utime, current->stime); + cutime = current->signal->cutime; + cstime = current->signal->cstime; + } else +#endif + { + + /* Process with multiple threads */ + struct task_struct *tsk = current; + struct task_struct *t; + read_lock(&tasklist_lock); + 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); + + /* + * While we have tasklist_lock read-locked, no dying thread + * can be updating current->signal->[us]time. Instead, + * we got their counts included in the live thread loop. + * However, another thread can come in right now and + * do a wait call that updates current->signal->c[us]time. + * To make sure we always see that pair updated atomically, + * we take the siglock around fetching them. + */ + spin_lock_irq(&tsk->sighand->siglock); + cutime = tsk->signal->cutime; + cstime = tsk->signal->cstime; + spin_unlock_irq(&tsk->sighand->siglock); + read_unlock(&tasklist_lock); + } tmp.tms_utime = cputime_to_clock_t(utime); tmp.tms_stime = cputime_to_clock_t(stime); tmp.tms_cutime = cputime_to_clock_t(cutime); @@ -1225,7 +1307,7 @@ static void groups_sort(struct group_info *group_info) } /* a simple bsearch */ -static int groups_search(struct group_info *group_info, gid_t grp) +int groups_search(struct group_info *group_info, gid_t grp) { int left, right; @@ -1652,7 +1734,7 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, error = 1; break; case PR_SET_DUMPABLE: - if (arg2 != 0 && arg2 != 1) { + if (arg2 < 0 || arg2 > 2) { error = -EINVAL; break; } |