kernel-ark/arch/i386/mach-voyager/voyager_thread.c
Alan Cox 0f0f1b400c [PATCH] Voyager: tty locking
Voyager fiddles with current->signal.tty without locking.  It turns out
that the code in question has already cleared current->signal.tty correctly
because daemonize() does the right thing already.

The signal handling also appears to be incorrect as it does an unprotected
sigfillset that also appears unneccessary.  As I don't have a bowtie and am
therefore not a qualified voyager maintainer I leave that to James.

Signed-off-by: Alan Cox <alan@redhat.com>
Acked-by: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:56 -07:00

163 lines
3.5 KiB
C

/* -*- mode: c; c-basic-offset: 8 -*- */
/* Copyright (C) 2001
*
* Author: J.E.J.Bottomley@HansenPartnership.com
*
* linux/arch/i386/kernel/voyager_thread.c
*
* This module provides the machine status monitor thread for the
* voyager architecture. This allows us to monitor the machine
* environment (temp, voltage, fan function) and the front panel and
* internal UPS. If a fault is detected, this thread takes corrective
* action (usually just informing init)
* */
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/kernel_stat.h>
#include <linux/delay.h>
#include <linux/mc146818rtc.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/kmod.h>
#include <linux/completion.h>
#include <linux/sched.h>
#include <asm/desc.h>
#include <asm/voyager.h>
#include <asm/vic.h>
#include <asm/mtrr.h>
#include <asm/msr.h>
#define THREAD_NAME "kvoyagerd"
/* external variables */
int kvoyagerd_running = 0;
DECLARE_MUTEX_LOCKED(kvoyagerd_sem);
static int thread(void *);
static __u8 set_timeout = 0;
/* Start the machine monitor thread. Return 1 if OK, 0 if fail */
static int __init
voyager_thread_start(void)
{
if(kernel_thread(thread, NULL, CLONE_KERNEL) < 0) {
/* This is serious, but not fatal */
printk(KERN_ERR "Voyager: Failed to create system monitor thread!!!\n");
return 1;
}
return 0;
}
static int
execute(const char *string)
{
int ret;
char *envp[] = {
"HOME=/",
"TERM=linux",
"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
NULL,
};
char *argv[] = {
"/bin/bash",
"-c",
(char *)string,
NULL,
};
if ((ret = call_usermodehelper(argv[0], argv, envp, 1)) != 0) {
printk(KERN_ERR "Voyager failed to run \"%s\": %i\n",
string, ret);
}
return ret;
}
static void
check_from_kernel(void)
{
if(voyager_status.switch_off) {
/* FIXME: This should be configureable via proc */
execute("umask 600; echo 0 > /etc/initrunlvl; kill -HUP 1");
} else if(voyager_status.power_fail) {
VDEBUG(("Voyager daemon detected AC power failure\n"));
/* FIXME: This should be configureable via proc */
execute("umask 600; echo F > /etc/powerstatus; kill -PWR 1");
set_timeout = 1;
}
}
static void
check_continuing_condition(void)
{
if(voyager_status.power_fail) {
__u8 data;
voyager_cat_psi(VOYAGER_PSI_SUBREAD,
VOYAGER_PSI_AC_FAIL_REG, &data);
if((data & 0x1f) == 0) {
/* all power restored */
printk(KERN_NOTICE "VOYAGER AC power restored, cancelling shutdown\n");
/* FIXME: should be user configureable */
execute("umask 600; echo O > /etc/powerstatus; kill -PWR 1");
set_timeout = 0;
}
}
}
static void
wakeup(unsigned long unused)
{
up(&kvoyagerd_sem);
}
static int
thread(void *unused)
{
struct timer_list wakeup_timer;
kvoyagerd_running = 1;
daemonize(THREAD_NAME);
set_timeout = 0;
init_timer(&wakeup_timer);
sigfillset(&current->blocked);
printk(KERN_NOTICE "Voyager starting monitor thread\n");
for(;;) {
down_interruptible(&kvoyagerd_sem);
VDEBUG(("Voyager Daemon awoken\n"));
if(voyager_status.request_from_kernel == 0) {
/* probably awoken from timeout */
check_continuing_condition();
} else {
check_from_kernel();
voyager_status.request_from_kernel = 0;
}
if(set_timeout) {
del_timer(&wakeup_timer);
wakeup_timer.expires = HZ + jiffies;
wakeup_timer.function = wakeup;
add_timer(&wakeup_timer);
}
}
}
static void __exit
voyager_thread_stop(void)
{
/* FIXME: do nothing at the moment */
}
module_init(voyager_thread_start);
//module_exit(voyager_thread_stop);