ACPI: thinkpad-acpi: add a safety net for TPEC fan control mode

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / proc / proc_misc.c

/*
 *  linux/fs/proc/proc_misc.c
 *
 *  linux/fs/proc/array.c
 *  Copyright (C) 1992  by Linus Torvalds
 *  based on ideas by Darren Senn
 *
 *  This used to be the part of array.c. See the rest of history and credits
 *  there. I took this into a separate file and switched the thing to generic
 *  proc_file_inode_operations, leaving in array.c only per-process stuff.
 *  Inumbers allocation made dynamic (via create_proc_entry()).  AV, May 1999.
 *
 * Changes:
 * Fulton Green      :  Encapsulated position metric calculations.
 *                      <kernel@FultonGreen.com>
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/kernel_stat.h>
#include <linux/fs.h>
#include <linux/tty.h>
#include <linux/string.h>
#include <linux/mman.h>
#include <linux/proc_fs.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/signal.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/seq_file.h>
#include <linux/times.h>
#include <linux/profile.h>
#include <linux/utsname.h>
#include <linux/blkdev.h>
#include <linux/hugetlb.h>
#include <linux/jiffies.h>
#include <linux/sysrq.h>
#include <linux/vmalloc.h>
#include <linux/crash_dump.h>
#include <linux/pid_namespace.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/tlb.h>
#include <asm/div64.h>
#include "internal.h"

#define LOAD_INT(x) ((x) >> FSHIFT)
#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
/*
 * Warning: stuff below (imported functions) assumes that its output will fit
 * into one page. For some of those functions it may be wrong. Moreover, we
 * have a way to deal with that gracefully. Right now I used straightforward
 * wrappers, but this needs further analysis wrt potential overflows.
 */
extern int get_hardware_list(char *);
extern int get_stram_list(char *);
extern int get_filesystem_list(char *);
extern int get_exec_domain_list(char *);
extern int get_dma_list(char *);
extern int get_locks_status (char *, char **, off_t, int);

static int proc_calc_metrics(char *page, char **start, off_t off,
                                 int count, int *eof, int len)
{
        if (len <= off+count) *eof = 1;
        *start = page + off;
        len -= off;
        if (len>count) len = count;
        if (len<0) len = 0;
        return len;
}

static int loadavg_read_proc(char *page, char **start, off_t off,
                                 int count, int *eof, void *data)
{
        int a, b, c;
        int len;

        a = avenrun[0] + (FIXED_1/200);
        b = avenrun[1] + (FIXED_1/200);
        c = avenrun[2] + (FIXED_1/200);
        len = sprintf(page,"%d.%02d %d.%02d %d.%02d %ld/%d %d\n",
                LOAD_INT(a), LOAD_FRAC(a),
                LOAD_INT(b), LOAD_FRAC(b),
                LOAD_INT(c), LOAD_FRAC(c),
                nr_running(), nr_threads, current->nsproxy->pid_ns->last_pid);
        return proc_calc_metrics(page, start, off, count, eof, len);
}

static int uptime_read_proc(char *page, char **start, off_t off,
                                 int count, int *eof, void *data)
{
        struct timespec uptime;
        struct timespec idle;
        int len;
        cputime_t idletime = cputime_add(init_task.utime, init_task.stime);

        do_posix_clock_monotonic_gettime(&uptime);
        cputime_to_timespec(idletime, &idle);
        len = sprintf(page,"%lu.%02lu %lu.%02lu\n",
                        (unsigned long) uptime.tv_sec,
                        (uptime.tv_nsec / (NSEC_PER_SEC / 100)),
                        (unsigned long) idle.tv_sec,
                        (idle.tv_nsec / (NSEC_PER_SEC / 100)));

        return proc_calc_metrics(page, start, off, count, eof, len);
}

static int meminfo_read_proc(char *page, char **start, off_t off,
                                 int count, int *eof, void *data)
{
        struct sysinfo i;
        int len;
        unsigned long inactive;
        unsigned long active;
        unsigned long free;
        unsigned long committed;
        unsigned long allowed;
        struct vmalloc_info vmi;
        long cached;

        get_zone_counts(&active, &inactive, &free);

/*
 * display in kilobytes.
 */
#define K(x) ((x) << (PAGE_SHIFT - 10))
        si_meminfo(&i);
        si_swapinfo(&i);
        committed = atomic_read(&vm_committed_space);
        allowed = ((totalram_pages - hugetlb_total_pages())
                * sysctl_overcommit_ratio / 100) + total_swap_pages;

        cached = global_page_state(NR_FILE_PAGES) -
                        total_swapcache_pages - i.bufferram;
        if (cached < 0)
                cached = 0;

        get_vmalloc_info(&vmi);

        /*
         * Tagged format, for easy grepping and expansion.
         */
        len = sprintf(page,
                "MemTotal:     %8lu kB\n"
                "MemFree:      %8lu kB\n"
                "Buffers:      %8lu kB\n"
                "Cached:       %8lu kB\n"
                "SwapCached:   %8lu kB\n"
                "Active:       %8lu kB\n"
                "Inactive:     %8lu kB\n"
#ifdef CONFIG_HIGHMEM
                "HighTotal:    %8lu kB\n"
                "HighFree:     %8lu kB\n"
                "LowTotal:     %8lu kB\n"
                "LowFree:      %8lu kB\n"
#endif
                "SwapTotal:    %8lu kB\n"
                "SwapFree:     %8lu kB\n"
                "Dirty:        %8lu kB\n"
                "Writeback:    %8lu kB\n"
                "AnonPages:    %8lu kB\n"
                "Mapped:       %8lu kB\n"
                "Slab:         %8lu kB\n"
                "SReclaimable: %8lu kB\n"
                "SUnreclaim:   %8lu kB\n"
                "PageTables:   %8lu kB\n"
                "NFS_Unstable: %8lu kB\n"
                "Bounce:       %8lu kB\n"
                "CommitLimit:  %8lu kB\n"
                "Committed_AS: %8lu kB\n"
                "VmallocTotal: %8lu kB\n"
                "VmallocUsed:  %8lu kB\n"
                "VmallocChunk: %8lu kB\n",
                K(i.totalram),
                K(i.freeram),
                K(i.bufferram),
                K(cached),
                K(total_swapcache_pages),
                K(active),
                K(inactive),
#ifdef CONFIG_HIGHMEM
                K(i.totalhigh),
                K(i.freehigh),
                K(i.totalram-i.totalhigh),
                K(i.freeram-i.freehigh),
#endif
                K(i.totalswap),
                K(i.freeswap),
                K(global_page_state(NR_FILE_DIRTY)),
                K(global_page_state(NR_WRITEBACK)),
                K(global_page_state(NR_ANON_PAGES)),
                K(global_page_state(NR_FILE_MAPPED)),
                K(global_page_state(NR_SLAB_RECLAIMABLE) +
                                global_page_state(NR_SLAB_UNRECLAIMABLE)),
                K(global_page_state(NR_SLAB_RECLAIMABLE)),
                K(global_page_state(NR_SLAB_UNRECLAIMABLE)),
                K(global_page_state(NR_PAGETABLE)),
                K(global_page_state(NR_UNSTABLE_NFS)),
                K(global_page_state(NR_BOUNCE)),
                K(allowed),
                K(committed),
                (unsigned long)VMALLOC_TOTAL >> 10,
                vmi.used >> 10,
                vmi.largest_chunk >> 10
                );

                len += hugetlb_report_meminfo(page + len);

        return proc_calc_metrics(page, start, off, count, eof, len);
#undef K
}

extern struct seq_operations fragmentation_op;
static int fragmentation_open(struct inode *inode, struct file *file)
{
        (void)inode;
        return seq_open(file, &fragmentation_op);
}

static struct file_operations fragmentation_file_operations = {
        .open           = fragmentation_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release,
};

extern struct seq_operations zoneinfo_op;
static int zoneinfo_open(struct inode *inode, struct file *file)
{
        return seq_open(file, &zoneinfo_op);
}

static struct file_operations proc_zoneinfo_file_operations = {
        .open           = zoneinfo_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release,
};

static int version_read_proc(char *page, char **start, off_t off,
                                 int count, int *eof, void *data)
{
        int len;

        len = snprintf(page, PAGE_SIZE, linux_proc_banner,
                utsname()->sysname,
                utsname()->release,
                utsname()->version);
        return proc_calc_metrics(page, start, off, count, eof, len);
}

extern struct seq_operations cpuinfo_op;
static int cpuinfo_open(struct inode *inode, struct file *file)
{
        return seq_open(file, &cpuinfo_op);
}

static struct file_operations proc_cpuinfo_operations = {
        .open           = cpuinfo_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release,
};

static int devinfo_show(struct seq_file *f, void *v)
{
        int i = *(loff_t *) v;

        if (i < CHRDEV_MAJOR_HASH_SIZE) {
                if (i == 0)
                        seq_printf(f, "Character devices:\n");
                chrdev_show(f, i);
        }
#ifdef CONFIG_BLOCK
        else {
                i -= CHRDEV_MAJOR_HASH_SIZE;
                if (i == 0)
                        seq_printf(f, "\nBlock devices:\n");
                blkdev_show(f, i);
        }
#endif
        return 0;
}

static void *devinfo_start(struct seq_file *f, loff_t *pos)
{
        if (*pos < (BLKDEV_MAJOR_HASH_SIZE + CHRDEV_MAJOR_HASH_SIZE))
                return pos;
        return NULL;
}

static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos)
{
        (*pos)++;
        if (*pos >= (BLKDEV_MAJOR_HASH_SIZE + CHRDEV_MAJOR_HASH_SIZE))
                return NULL;
        return pos;
}

static void devinfo_stop(struct seq_file *f, void *v)
{
        /* Nothing to do */
}

static struct seq_operations devinfo_ops = {
        .start = devinfo_start,
        .next  = devinfo_next,
        .stop  = devinfo_stop,
        .show  = devinfo_show
};

static int devinfo_open(struct inode *inode, struct file *filp)
{
        return seq_open(filp, &devinfo_ops);
}

static struct file_operations proc_devinfo_operations = {
        .open           = devinfo_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release,
};

extern struct seq_operations vmstat_op;
static int vmstat_open(struct inode *inode, struct file *file)
{
        return seq_open(file, &vmstat_op);
}
static struct file_operations proc_vmstat_file_operations = {
        .open           = vmstat_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release,
};

#ifdef CONFIG_PROC_HARDWARE
static int hardware_read_proc(char *page, char **start, off_t off,
                                 int count, int *eof, void *data)
{
        int len = get_hardware_list(page);
        return proc_calc_metrics(page, start, off, count, eof, len);
}
#endif

#ifdef CONFIG_STRAM_PROC
static int stram_read_proc(char *page, char **start, off_t off,
                                 int count, int *eof, void *data)
{
        int len = get_stram_list(page);
        return proc_calc_metrics(page, start, off, count, eof, len);
}
#endif

#ifdef CONFIG_BLOCK
extern struct seq_operations partitions_op;
static int partitions_open(struct inode *inode, struct file *file)
{
        return seq_open(file, &partitions_op);
}
static struct file_operations proc_partitions_operations = {
        .open           = partitions_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release,
};

extern struct seq_operations diskstats_op;
static int diskstats_open(struct inode *inode, struct file *file)
{
        return seq_open(file, &diskstats_op);
}
static struct file_operations proc_diskstats_operations = {
        .open           = diskstats_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release,
};
#endif

#ifdef CONFIG_MODULES
extern struct seq_operations modules_op;
static int modules_open(struct inode *inode, struct file *file)
{
        return seq_open(file, &modules_op);
}
static struct file_operations proc_modules_operations = {
        .open           = modules_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release,
};
#endif

#ifdef CONFIG_SLAB
extern struct seq_operations slabinfo_op;
extern ssize_t slabinfo_write(struct file *, const char __user *, size_t, loff_t *);
static int slabinfo_open(struct inode *inode, struct file *file)
{
        return seq_open(file, &slabinfo_op);
}
static struct file_operations proc_slabinfo_operations = {
        .open           = slabinfo_open,
        .read           = seq_read,
        .write          = slabinfo_write,
        .llseek         = seq_lseek,
        .release        = seq_release,
};

#ifdef CONFIG_DEBUG_SLAB_LEAK
extern struct seq_operations slabstats_op;
static int slabstats_open(struct inode *inode, struct file *file)
{
        unsigned long *n = kzalloc(PAGE_SIZE, GFP_KERNEL);
        int ret = -ENOMEM;
        if (n) {
                ret = seq_open(file, &slabstats_op);
                if (!ret) {
                        struct seq_file *m = file->private_data;
                        *n = PAGE_SIZE / (2 * sizeof(unsigned long));
                        m->private = n;
                        n = NULL;
                }
                kfree(n);
        }
        return ret;
}

static int slabstats_release(struct inode *inode, struct file *file)
{
        struct seq_file *m = file->private_data;
        kfree(m->private);
        return seq_release(inode, file);
}

static struct file_operations proc_slabstats_operations = {
        .open           = slabstats_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = slabstats_release,
};
#endif
#endif

static int show_stat(struct seq_file *p, void *v)
{
        int i;
        unsigned long jif;
        cputime64_t user, nice, system, idle, iowait, irq, softirq, steal;
        u64 sum = 0;

        user = nice = system = idle = iowait =
                irq = softirq = steal = cputime64_zero;
        jif = - wall_to_monotonic.tv_sec;
        if (wall_to_monotonic.tv_nsec)
                --jif;

        for_each_possible_cpu(i) {
                int j;

                user = cputime64_add(user, kstat_cpu(i).cpustat.user);
                nice = cputime64_add(nice, kstat_cpu(i).cpustat.nice);
                system = cputime64_add(system, kstat_cpu(i).cpustat.system);
                idle = cputime64_add(idle, kstat_cpu(i).cpustat.idle);
                iowait = cputime64_add(iowait, kstat_cpu(i).cpustat.iowait);
                irq = cputime64_add(irq, kstat_cpu(i).cpustat.irq);
                softirq = cputime64_add(softirq, kstat_cpu(i).cpustat.softirq);
                steal = cputime64_add(steal, kstat_cpu(i).cpustat.steal);
                for (j = 0 ; j < NR_IRQS ; j++)
                        sum += kstat_cpu(i).irqs[j];
        }

        seq_printf(p, "cpu  %llu %llu %llu %llu %llu %llu %llu %llu\n",
                (unsigned long long)cputime64_to_clock_t(user),
                (unsigned long long)cputime64_to_clock_t(nice),
                (unsigned long long)cputime64_to_clock_t(system),
                (unsigned long long)cputime64_to_clock_t(idle),
                (unsigned long long)cputime64_to_clock_t(iowait),
                (unsigned long long)cputime64_to_clock_t(irq),
                (unsigned long long)cputime64_to_clock_t(softirq),
                (unsigned long long)cputime64_to_clock_t(steal));
        for_each_online_cpu(i) {

                /* Copy values here to work around gcc-2.95.3, gcc-2.96 */
                user = kstat_cpu(i).cpustat.user;
                nice = kstat_cpu(i).cpustat.nice;
                system = kstat_cpu(i).cpustat.system;
                idle = kstat_cpu(i).cpustat.idle;
                iowait = kstat_cpu(i).cpustat.iowait;
                irq = kstat_cpu(i).cpustat.irq;
                softirq = kstat_cpu(i).cpustat.softirq;
                steal = kstat_cpu(i).cpustat.steal;
                seq_printf(p, "cpu%d %llu %llu %llu %llu %llu %llu %llu %llu\n",
                        i,
                        (unsigned long long)cputime64_to_clock_t(user),
                        (unsigned long long)cputime64_to_clock_t(nice),
                        (unsigned long long)cputime64_to_clock_t(system),
                        (unsigned long long)cputime64_to_clock_t(idle),
                        (unsigned long long)cputime64_to_clock_t(iowait),
                        (unsigned long long)cputime64_to_clock_t(irq),
                        (unsigned long long)cputime64_to_clock_t(softirq),
                        (unsigned long long)cputime64_to_clock_t(steal));
        }
        seq_printf(p, "intr %llu", (unsigned long long)sum);

#if !defined(CONFIG_PPC64) && !defined(CONFIG_ALPHA) && !defined(CONFIG_IA64)
        for (i = 0; i < NR_IRQS; i++)
                seq_printf(p, " %u", kstat_irqs(i));
#endif

        seq_printf(p,
                "\nctxt %llu\n"
                "btime %lu\n"
                "processes %lu\n"
                "procs_running %lu\n"
                "procs_blocked %lu\n",
                nr_context_switches(),
                (unsigned long)jif,
                total_forks,
                nr_running(),
                nr_iowait());

        return 0;
}

static int stat_open(struct inode *inode, struct file *file)
{
        unsigned size = 4096 * (1 + num_possible_cpus() / 32);
        char *buf;
        struct seq_file *m;
        int res;

        /* don't ask for more than the kmalloc() max size, currently 128 KB */
        if (size > 128 * 1024)
                size = 128 * 1024;
        buf = kmalloc(size, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        res = single_open(file, show_stat, NULL);
        if (!res) {
                m = file->private_data;
                m->buf = buf;
                m->size = size;
        } else
                kfree(buf);
        return res;
}
static struct file_operations proc_stat_operations = {
        .open           = stat_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

/*
 * /proc/interrupts
 */
static void *int_seq_start(struct seq_file *f, loff_t *pos)
{
        return (*pos <= NR_IRQS) ? pos : NULL;
}

static void *int_seq_next(struct seq_file *f, void *v, loff_t *pos)
{
        (*pos)++;
        if (*pos > NR_IRQS)
                return NULL;
        return pos;
}

static void int_seq_stop(struct seq_file *f, void *v)
{
        /* Nothing to do */
}


extern int show_interrupts(struct seq_file *f, void *v); /* In arch code */
static struct seq_operations int_seq_ops = {
        .start = int_seq_start,
        .next  = int_seq_next,
        .stop  = int_seq_stop,
        .show  = show_interrupts
};

static int interrupts_open(struct inode *inode, struct file *filp)
{
        return seq_open(filp, &int_seq_ops);
}

static struct file_operations proc_interrupts_operations = {
        .open           = interrupts_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release,
};

static int filesystems_read_proc(char *page, char **start, off_t off,
                                 int count, int *eof, void *data)
{
        int len = get_filesystem_list(page);
        return proc_calc_metrics(page, start, off, count, eof, len);
}

static int cmdline_read_proc(char *page, char **start, off_t off,
                                 int count, int *eof, void *data)
{
        int len;

        len = sprintf(page, "%s\n", saved_command_line);
        return proc_calc_metrics(page, start, off, count, eof, len);
}

static int locks_read_proc(char *page, char **start, off_t off,
                                 int count, int *eof, void *data)
{
        int len = get_locks_status(page, start, off, count);

        if (len < count)
                *eof = 1;
        return len;
}

static int execdomains_read_proc(char *page, char **start, off_t off,
                                 int count, int *eof, void *data)
{
        int len = get_exec_domain_list(page);
        return proc_calc_metrics(page, start, off, count, eof, len);
}

#ifdef CONFIG_MAGIC_SYSRQ
/*
 * writing 'C' to /proc/sysrq-trigger is like sysrq-C
 */
static ssize_t write_sysrq_trigger(struct file *file, const char __user *buf,
                                   size_t count, loff_t *ppos)
{
        if (count) {
                char c;

                if (get_user(c, buf))
                        return -EFAULT;
                __handle_sysrq(c, NULL, 0);
        }
        return count;
}

static struct file_operations proc_sysrq_trigger_operations = {
        .write          = write_sysrq_trigger,
};
#endif

struct proc_dir_entry *proc_root_kcore;

void create_seq_entry(char *name, mode_t mode, const struct file_operations *f)
{
        struct proc_dir_entry *entry;
        entry = create_proc_entry(name, mode, NULL);
        if (entry)
                entry->proc_fops = f;
}

void __init proc_misc_init(void)
{
        struct proc_dir_entry *entry;
        static struct {
                char *name;
                int (*read_proc)(char*,char**,off_t,int,int*,void*);
        } *p, simple_ones[] = {
                {"loadavg",     loadavg_read_proc},
                {"uptime",      uptime_read_proc},
                {"meminfo",     meminfo_read_proc},
                {"version",     version_read_proc},
#ifdef CONFIG_PROC_HARDWARE
                {"hardware",    hardware_read_proc},
#endif
#ifdef CONFIG_STRAM_PROC
                {"stram",       stram_read_proc},
#endif
                {"filesystems", filesystems_read_proc},
                {"cmdline",     cmdline_read_proc},
                {"locks",       locks_read_proc},
                {"execdomains", execdomains_read_proc},
                {NULL,}
        };
        for (p = simple_ones; p->name; p++)
                create_proc_read_entry(p->name, 0, NULL, p->read_proc, NULL);

        proc_symlink("mounts", NULL, "self/mounts");

        /* And now for trickier ones */
#ifdef CONFIG_PRINTK
        entry = create_proc_entry("kmsg", S_IRUSR, &proc_root);
        if (entry)
                entry->proc_fops = &proc_kmsg_operations;
#endif
        create_seq_entry("devices", 0, &proc_devinfo_operations);
        create_seq_entry("cpuinfo", 0, &proc_cpuinfo_operations);
#ifdef CONFIG_BLOCK
        create_seq_entry("partitions", 0, &proc_partitions_operations);
#endif
        create_seq_entry("stat", 0, &proc_stat_operations);
        create_seq_entry("interrupts", 0, &proc_interrupts_operations);
#ifdef CONFIG_SLAB
        create_seq_entry("slabinfo",S_IWUSR|S_IRUGO,&proc_slabinfo_operations);
#ifdef CONFIG_DEBUG_SLAB_LEAK
        create_seq_entry("slab_allocators", 0 ,&proc_slabstats_operations);
#endif
#endif
        create_seq_entry("buddyinfo",S_IRUGO, &fragmentation_file_operations);
        create_seq_entry("vmstat",S_IRUGO, &proc_vmstat_file_operations);
        create_seq_entry("zoneinfo",S_IRUGO, &proc_zoneinfo_file_operations);
#ifdef CONFIG_BLOCK
        create_seq_entry("diskstats", 0, &proc_diskstats_operations);
#endif
#ifdef CONFIG_MODULES
        create_seq_entry("modules", 0, &proc_modules_operations);
#endif
#ifdef CONFIG_SCHEDSTATS
        create_seq_entry("schedstat", 0, &proc_schedstat_operations);
#endif
#ifdef CONFIG_PROC_KCORE
        proc_root_kcore = create_proc_entry("kcore", S_IRUSR, NULL);
        if (proc_root_kcore) {
                proc_root_kcore->proc_fops = &proc_kcore_operations;
                proc_root_kcore->size =
                                (size_t)high_memory - PAGE_OFFSET + PAGE_SIZE;
        }
#endif
#ifdef CONFIG_PROC_VMCORE
        proc_vmcore = create_proc_entry("vmcore", S_IRUSR, NULL);
        if (proc_vmcore)
                proc_vmcore->proc_fops = &proc_vmcore_operations;
#endif
#ifdef CONFIG_MAGIC_SYSRQ
        entry = create_proc_entry("sysrq-trigger", S_IWUSR, NULL);
        if (entry)
                entry->proc_fops = &proc_sysrq_trigger_operations;
#endif
}