Serialization of sys_reboot can be done local. The BKL is not protecting anything else. Signed-off-by: Thomas Gleixner --- kernel/sys.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) Index: linux-2.6-tip/kernel/sys.c =================================================================== --- linux-2.6-tip.orig/kernel/sys.c +++ linux-2.6-tip/kernel/sys.c @@ -8,7 +8,6 @@ #include #include #include -#include #include #include #include @@ -349,6 +348,9 @@ void kernel_power_off(void) machine_power_off(); } EXPORT_SYMBOL_GPL(kernel_power_off); + +static DEFINE_MUTEX(reboot_mutex); + /* * Reboot system call: for obvious reasons only root may call it, * and even root needs to set up some magic numbers in the registers @@ -381,7 +383,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) cmd = LINUX_REBOOT_CMD_HALT; - lock_kernel(); + mutex_lock(&reboot_mutex); switch (cmd) { case LINUX_REBOOT_CMD_RESTART: kernel_restart(NULL); @@ -397,20 +399,18 @@ SYSCALL_DEFINE4(reboot, int, magic1, int case LINUX_REBOOT_CMD_HALT: kernel_halt(); - unlock_kernel(); do_exit(0); panic("cannot halt"); 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; + ret = -EFAULT; + break; } buffer[sizeof(buffer) - 1] = '\0'; @@ -433,7 +433,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int ret = -EINVAL; break; } - unlock_kernel(); + mutex_unlock(&reboot_mutex); return ret; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/