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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: Thomas Gleixner <tglx@linutronix.de>
wifi-calibration
Thomas Gleixner 2009-10-09 20:31:33 +02:00
parent 1a6deaea35
commit 6f15fa5008
1 changed files with 7 additions and 7 deletions
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14
kernel/sys.c
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@ -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;
} }