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/*

 * linux/kernel/info.c

 *

 * Copyright (C) 1992 Darren Senn

 */

/* This implements the sysinfo() system call */

#include <linux/mm.h>

#include <linux/unistd.h>

#include <linux/swap.h>

#include <linux/smp_lock.h>

#include <asm/uaccess.h>

asmlinkage long sys_sysinfo(struct sysinfo *info)

{

        struct sysinfo val;

        memset((char *)&val, 0, sizeof(struct sysinfo));

        cli();

        val.uptime = jiffies / HZ;

        val.loads[0] = avenrun[0] << (SI_LOAD_SHIFT - FSHIFT);

        val.loads[1] = avenrun[1] << (SI_LOAD_SHIFT - FSHIFT);

        val.loads[2] = avenrun[2] << (SI_LOAD_SHIFT - FSHIFT);

        val.procs = nr_threads-1;

        sti();

        si_meminfo(&val);

        si_swapinfo(&val);

        {

                unsigned long mem_total, sav_total;

                unsigned int mem_unit, bitcount;

                /* If the sum of all the available memory (i.e. ram + swap)

                 * is less than can be stored in a 32 bit unsigned long then

                 * we can be binary compatible with 2.2.x kernels.  If not,

                 * well, in that case 2.2.x was broken anyways...

                 *

                 *  -Erik Andersen <andersee@debian.org> */

                mem_total = val.totalram + val.totalswap;

                if (mem_total < val.totalram || mem_total < val.totalswap)

                        goto out;

                bitcount = 0;

                mem_unit = val.mem_unit;

                while (mem_unit > 1) {

                        bitcount++;

                        mem_unit >>= 1;

                        sav_total = mem_total;

                        mem_total <<= 1;

                        if (mem_total < sav_total)

                                goto out;

                }

                /* If mem_total did not overflow, multiply all memory values by

                 * val.mem_unit and set it to 1.  This leaves things compatible

                 * with 2.2.x, and also retains compatibility with earlier 2.4.x

                 * kernels...  */

                val.mem_unit = 1;

                val.totalram <<= bitcount;

                val.freeram <<= bitcount;

                val.sharedram <<= bitcount;

                val.bufferram <<= bitcount;

                val.totalswap <<= bitcount;

                val.freeswap <<= bitcount;

                val.totalhigh <<= bitcount;

                val.freehigh <<= bitcount;

        }

out:

        if (copy_to_user(info, &val, sizeof(struct sysinfo)))

                return -EFAULT;

        return 0;

}