Commit 6f15fa50 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

sys: Remove BKL from sys_reboot 



Serialization of sys_reboot can be done local. The BKL is not
protecting anything else.

LKML-Reference: <20091010153349.405590702@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 1a6deaea

kernel/sys.c

+7 −7
Original line number Original line Diff line number Diff line
@@ -8,7 +8,6 @@ 
#include <linux/mm.h>

#include <linux/mm.h>

#include <linux/utsname.h>

#include <linux/utsname.h>

#include <linux/mman.h>

#include <linux/mman.h>

#include <linux/smp_lock.h>

#include <linux/notifier.h>

#include <linux/notifier.h>

#include <linux/reboot.h>

#include <linux/reboot.h>

#include <linux/prctl.h>

#include <linux/prctl.h>
@@ -349,6 +348,9 @@ void kernel_power_off(void) 
	machine_power_off();

	machine_power_off();

}

}

EXPORT_SYMBOL_GPL(kernel_power_off);

EXPORT_SYMBOL_GPL(kernel_power_off);



static DEFINE_MUTEX(reboot_mutex);



/*

/*

 * Reboot system call: for obvious reasons only root may call it,

 * Reboot system call: for obvious reasons only root may call it,

 * and even root needs to set up some magic numbers in the registers

 * and even root needs to set up some magic numbers in the registers
@@ -381,7 +383,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, 
	if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)

	if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)

		cmd = LINUX_REBOOT_CMD_HALT;

		cmd = LINUX_REBOOT_CMD_HALT;





	lock_kernel();

	mutex_lock(&reboot_mutex);

	switch (cmd) {

	switch (cmd) {

	case LINUX_REBOOT_CMD_RESTART:

	case LINUX_REBOOT_CMD_RESTART:

		kernel_restart(NULL);

		kernel_restart(NULL);
@@ -397,20 +399,18 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, 




	case LINUX_REBOOT_CMD_HALT:

	case LINUX_REBOOT_CMD_HALT:

		kernel_halt();

		kernel_halt();

		unlock_kernel();

		do_exit(0);

		do_exit(0);

		panic("cannot halt");

		panic("cannot halt");





	case LINUX_REBOOT_CMD_POWER_OFF:

	case LINUX_REBOOT_CMD_POWER_OFF:

		kernel_power_off();

		kernel_power_off();

		unlock_kernel();

		do_exit(0);

		do_exit(0);

		break;

		break;





	case LINUX_REBOOT_CMD_RESTART2:

	case LINUX_REBOOT_CMD_RESTART2:

		if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {

		if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {

			unlock_kernel();

			ret = -EFAULT;

			return -EFAULT;

			break;

		}

		}

		buffer[sizeof(buffer) - 1] = '\0';

		buffer[sizeof(buffer) - 1] = '\0';
@@ -433,7 +433,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, 
		ret = -EINVAL;

		ret = -EINVAL;

		break;

		break;

	}

	}

	unlock_kernel();

	mutex_unlock(&reboot_mutex);

	return ret;

	return ret;

}

}