Merge tag 'kvm-x86-generic-6.8' of https://github.com/kvm-x86/linux into HEAD

[thirdparty/kernel/stable.git] / kernel / sysctl.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * sysctl.c: General linux system control interface
 *
 * Begun 24 March 1995, Stephen Tweedie
 * Added /proc support, Dec 1995
 * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
 * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
 * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
 * Dynamic registration fixes, Stephen Tweedie.
 * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
 * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
 *  Horn.
 * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
 * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
 * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
 *  Wendling.
 * The list_for_each() macro wasn't appropriate for the sysctl loop.
 *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
 */

#include <linux/module.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/bitmap.h>
#include <linux/signal.h>
#include <linux/panic.h>
#include <linux/printk.h>
#include <linux/proc_fs.h>
#include <linux/security.h>
#include <linux/ctype.h>
#include <linux/kmemleak.h>
#include <linux/filter.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/net.h>
#include <linux/sysrq.h>
#include <linux/highuid.h>
#include <linux/writeback.h>
#include <linux/ratelimit.h>
#include <linux/hugetlb.h>
#include <linux/initrd.h>
#include <linux/key.h>
#include <linux/times.h>
#include <linux/limits.h>
#include <linux/dcache.h>
#include <linux/syscalls.h>
#include <linux/vmstat.h>
#include <linux/nfs_fs.h>
#include <linux/acpi.h>
#include <linux/reboot.h>
#include <linux/ftrace.h>
#include <linux/perf_event.h>
#include <linux/oom.h>
#include <linux/kmod.h>
#include <linux/capability.h>
#include <linux/binfmts.h>
#include <linux/sched/sysctl.h>
#include <linux/mount.h>
#include <linux/userfaultfd_k.h>
#include <linux/pid.h>

#include "../lib/kstrtox.h"

#include <linux/uaccess.h>
#include <asm/processor.h>

#ifdef CONFIG_X86
#include <asm/nmi.h>
#include <asm/stacktrace.h>
#include <asm/io.h>
#endif
#ifdef CONFIG_SPARC
#include <asm/setup.h>
#endif
#ifdef CONFIG_RT_MUTEXES
#include <linux/rtmutex.h>
#endif

/* shared constants to be used in various sysctls */
const int sysctl_vals[] = { 0, 1, 2, 3, 4, 100, 200, 1000, 3000, INT_MAX, 65535, -1 };
EXPORT_SYMBOL(sysctl_vals);

const unsigned long sysctl_long_vals[] = { 0, 1, LONG_MAX };
EXPORT_SYMBOL_GPL(sysctl_long_vals);

#if defined(CONFIG_SYSCTL)

/* Constants used for minimum and maximum */

#ifdef CONFIG_PERF_EVENTS
static const int six_hundred_forty_kb = 640 * 1024;
#endif


static const int ngroups_max = NGROUPS_MAX;
static const int cap_last_cap = CAP_LAST_CAP;

#ifdef CONFIG_PROC_SYSCTL

/**
 * enum sysctl_writes_mode - supported sysctl write modes
 *
 * @SYSCTL_WRITES_LEGACY: each write syscall must fully contain the sysctl value
 *      to be written, and multiple writes on the same sysctl file descriptor
 *      will rewrite the sysctl value, regardless of file position. No warning
 *      is issued when the initial position is not 0.
 * @SYSCTL_WRITES_WARN: same as above but warn when the initial file position is
 *      not 0.
 * @SYSCTL_WRITES_STRICT: writes to numeric sysctl entries must always be at
 *      file position 0 and the value must be fully contained in the buffer
 *      sent to the write syscall. If dealing with strings respect the file
 *      position, but restrict this to the max length of the buffer, anything
 *      passed the max length will be ignored. Multiple writes will append
 *      to the buffer.
 *
 * These write modes control how current file position affects the behavior of
 * updating sysctl values through the proc interface on each write.
 */
enum sysctl_writes_mode {
        SYSCTL_WRITES_LEGACY            = -1,
        SYSCTL_WRITES_WARN              = 0,
        SYSCTL_WRITES_STRICT            = 1,
};

static enum sysctl_writes_mode sysctl_writes_strict = SYSCTL_WRITES_STRICT;
#endif /* CONFIG_PROC_SYSCTL */

#if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \
    defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT)
int sysctl_legacy_va_layout;
#endif

#endif /* CONFIG_SYSCTL */

/*
 * /proc/sys support
 */

#ifdef CONFIG_PROC_SYSCTL

static int _proc_do_string(char *data, int maxlen, int write,
                char *buffer, size_t *lenp, loff_t *ppos)
{
        size_t len;
        char c, *p;

        if (!data || !maxlen || !*lenp) {
                *lenp = 0;
                return 0;
        }

        if (write) {
                if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
                        /* Only continue writes not past the end of buffer. */
                        len = strlen(data);
                        if (len > maxlen - 1)
                                len = maxlen - 1;

                        if (*ppos > len)
                                return 0;
                        len = *ppos;
                } else {
                        /* Start writing from beginning of buffer. */
                        len = 0;
                }

                *ppos += *lenp;
                p = buffer;
                while ((p - buffer) < *lenp && len < maxlen - 1) {
                        c = *(p++);
                        if (c == 0 || c == '\n')
                                break;
                        data[len++] = c;
                }
                data[len] = 0;
        } else {
                len = strlen(data);
                if (len > maxlen)
                        len = maxlen;

                if (*ppos > len) {
                        *lenp = 0;
                        return 0;
                }

                data += *ppos;
                len  -= *ppos;

                if (len > *lenp)
                        len = *lenp;
                if (len)
                        memcpy(buffer, data, len);
                if (len < *lenp) {
                        buffer[len] = '\n';
                        len++;
                }
                *lenp = len;
                *ppos += len;
        }
        return 0;
}

static void warn_sysctl_write(struct ctl_table *table)
{
        pr_warn_once("%s wrote to %s when file position was not 0!\n"
                "This will not be supported in the future. To silence this\n"
                "warning, set kernel.sysctl_writes_strict = -1\n",
                current->comm, table->procname);
}

/**
 * proc_first_pos_non_zero_ignore - check if first position is allowed
 * @ppos: file position
 * @table: the sysctl table
 *
 * Returns true if the first position is non-zero and the sysctl_writes_strict
 * mode indicates this is not allowed for numeric input types. String proc
 * handlers can ignore the return value.
 */
static bool proc_first_pos_non_zero_ignore(loff_t *ppos,
                                           struct ctl_table *table)
{
        if (!*ppos)
                return false;

        switch (sysctl_writes_strict) {
        case SYSCTL_WRITES_STRICT:
                return true;
        case SYSCTL_WRITES_WARN:
                warn_sysctl_write(table);
                return false;
        default:
                return false;
        }
}

/**
 * proc_dostring - read a string sysctl
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes a string from/to the user buffer. If the kernel
 * buffer provided is not large enough to hold the string, the
 * string is truncated. The copied string is %NULL-terminated.
 * If the string is being read by the user process, it is copied
 * and a newline '\n' is added. It is truncated if the buffer is
 * not large enough.
 *
 * Returns 0 on success.
 */
int proc_dostring(struct ctl_table *table, int write,
                  void *buffer, size_t *lenp, loff_t *ppos)
{
        if (write)
                proc_first_pos_non_zero_ignore(ppos, table);

        return _proc_do_string(table->data, table->maxlen, write, buffer, lenp,
                        ppos);
}

static void proc_skip_spaces(char **buf, size_t *size)
{
        while (*size) {
                if (!isspace(**buf))
                        break;
                (*size)--;
                (*buf)++;
        }
}

static void proc_skip_char(char **buf, size_t *size, const char v)
{
        while (*size) {
                if (**buf != v)
                        break;
                (*size)--;
                (*buf)++;
        }
}

/**
 * strtoul_lenient - parse an ASCII formatted integer from a buffer and only
 *                   fail on overflow
 *
 * @cp: kernel buffer containing the string to parse
 * @endp: pointer to store the trailing characters
 * @base: the base to use
 * @res: where the parsed integer will be stored
 *
 * In case of success 0 is returned and @res will contain the parsed integer,
 * @endp will hold any trailing characters.
 * This function will fail the parse on overflow. If there wasn't an overflow
 * the function will defer the decision what characters count as invalid to the
 * caller.
 */
static int strtoul_lenient(const char *cp, char **endp, unsigned int base,
                           unsigned long *res)
{
        unsigned long long result;
        unsigned int rv;

        cp = _parse_integer_fixup_radix(cp, &base);
        rv = _parse_integer(cp, base, &result);
        if ((rv & KSTRTOX_OVERFLOW) || (result != (unsigned long)result))
                return -ERANGE;

        cp += rv;

        if (endp)
                *endp = (char *)cp;

        *res = (unsigned long)result;
        return 0;
}

#define TMPBUFLEN 22
/**
 * proc_get_long - reads an ASCII formatted integer from a user buffer
 *
 * @buf: a kernel buffer
 * @size: size of the kernel buffer
 * @val: this is where the number will be stored
 * @neg: set to %TRUE if number is negative
 * @perm_tr: a vector which contains the allowed trailers
 * @perm_tr_len: size of the perm_tr vector
 * @tr: pointer to store the trailer character
 *
 * In case of success %0 is returned and @buf and @size are updated with
 * the amount of bytes read. If @tr is non-NULL and a trailing
 * character exists (size is non-zero after returning from this
 * function), @tr is updated with the trailing character.
 */
static int proc_get_long(char **buf, size_t *size,
                          unsigned long *val, bool *neg,
                          const char *perm_tr, unsigned perm_tr_len, char *tr)
{
        char *p, tmp[TMPBUFLEN];
        ssize_t len = *size;

        if (len <= 0)
                return -EINVAL;

        if (len > TMPBUFLEN - 1)
                len = TMPBUFLEN - 1;

        memcpy(tmp, *buf, len);

        tmp[len] = 0;
        p = tmp;
        if (*p == '-' && *size > 1) {
                *neg = true;
                p++;
        } else
                *neg = false;
        if (!isdigit(*p))
                return -EINVAL;

        if (strtoul_lenient(p, &p, 0, val))
                return -EINVAL;

        len = p - tmp;

        /* We don't know if the next char is whitespace thus we may accept
         * invalid integers (e.g. 1234...a) or two integers instead of one
         * (e.g. 123...1). So lets not allow such large numbers. */
        if (len == TMPBUFLEN - 1)
                return -EINVAL;

        if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
                return -EINVAL;

        if (tr && (len < *size))
                *tr = *p;

        *buf += len;
        *size -= len;

        return 0;
}

/**
 * proc_put_long - converts an integer to a decimal ASCII formatted string
 *
 * @buf: the user buffer
 * @size: the size of the user buffer
 * @val: the integer to be converted
 * @neg: sign of the number, %TRUE for negative
 *
 * In case of success @buf and @size are updated with the amount of bytes
 * written.
 */
static void proc_put_long(void **buf, size_t *size, unsigned long val, bool neg)
{
        int len;
        char tmp[TMPBUFLEN], *p = tmp;

        sprintf(p, "%s%lu", neg ? "-" : "", val);
        len = strlen(tmp);
        if (len > *size)
                len = *size;
        memcpy(*buf, tmp, len);
        *size -= len;
        *buf += len;
}
#undef TMPBUFLEN

static void proc_put_char(void **buf, size_t *size, char c)
{
        if (*size) {
                char **buffer = (char **)buf;
                **buffer = c;

                (*size)--;
                (*buffer)++;
                *buf = *buffer;
        }
}

static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
                                 int *valp,
                                 int write, void *data)
{
        if (write) {
                if (*negp) {
                        if (*lvalp > (unsigned long) INT_MAX + 1)
                                return -EINVAL;
                        WRITE_ONCE(*valp, -*lvalp);
                } else {
                        if (*lvalp > (unsigned long) INT_MAX)
                                return -EINVAL;
                        WRITE_ONCE(*valp, *lvalp);
                }
        } else {
                int val = READ_ONCE(*valp);
                if (val < 0) {
                        *negp = true;
                        *lvalp = -(unsigned long)val;
                } else {
                        *negp = false;
                        *lvalp = (unsigned long)val;
                }
        }
        return 0;
}

static int do_proc_douintvec_conv(unsigned long *lvalp,
                                  unsigned int *valp,
                                  int write, void *data)
{
        if (write) {
                if (*lvalp > UINT_MAX)
                        return -EINVAL;
                WRITE_ONCE(*valp, *lvalp);
        } else {
                unsigned int val = READ_ONCE(*valp);
                *lvalp = (unsigned long)val;
        }
        return 0;
}

static const char proc_wspace_sep[] = { ' ', '\t', '\n' };

static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
                  int write, void *buffer,
                  size_t *lenp, loff_t *ppos,
                  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
                              int write, void *data),
                  void *data)
{
        int *i, vleft, first = 1, err = 0;
        size_t left;
        char *p;

        if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
                *lenp = 0;
                return 0;
        }

        i = (int *) tbl_data;
        vleft = table->maxlen / sizeof(*i);
        left = *lenp;

        if (!conv)
                conv = do_proc_dointvec_conv;

        if (write) {
                if (proc_first_pos_non_zero_ignore(ppos, table))
                        goto out;

                if (left > PAGE_SIZE - 1)
                        left = PAGE_SIZE - 1;
                p = buffer;
        }

        for (; left && vleft--; i++, first=0) {
                unsigned long lval;
                bool neg;

                if (write) {
                        proc_skip_spaces(&p, &left);

                        if (!left)
                                break;
                        err = proc_get_long(&p, &left, &lval, &neg,
                                             proc_wspace_sep,
                                             sizeof(proc_wspace_sep), NULL);
                        if (err)
                                break;
                        if (conv(&neg, &lval, i, 1, data)) {
                                err = -EINVAL;
                                break;
                        }
                } else {
                        if (conv(&neg, &lval, i, 0, data)) {
                                err = -EINVAL;
                                break;
                        }
                        if (!first)
                                proc_put_char(&buffer, &left, '\t');
                        proc_put_long(&buffer, &left, lval, neg);
                }
        }

        if (!write && !first && left && !err)
                proc_put_char(&buffer, &left, '\n');
        if (write && !err && left)
                proc_skip_spaces(&p, &left);
        if (write && first)
                return err ? : -EINVAL;
        *lenp -= left;
out:
        *ppos += *lenp;
        return err;
}

static int do_proc_dointvec(struct ctl_table *table, int write,
                  void *buffer, size_t *lenp, loff_t *ppos,
                  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
                              int write, void *data),
                  void *data)
{
        return __do_proc_dointvec(table->data, table, write,
                        buffer, lenp, ppos, conv, data);
}

static int do_proc_douintvec_w(unsigned int *tbl_data,
                               struct ctl_table *table,
                               void *buffer,
                               size_t *lenp, loff_t *ppos,
                               int (*conv)(unsigned long *lvalp,
                                           unsigned int *valp,
                                           int write, void *data),
                               void *data)
{
        unsigned long lval;
        int err = 0;
        size_t left;
        bool neg;
        char *p = buffer;

        left = *lenp;

        if (proc_first_pos_non_zero_ignore(ppos, table))
                goto bail_early;

        if (left > PAGE_SIZE - 1)
                left = PAGE_SIZE - 1;

        proc_skip_spaces(&p, &left);
        if (!left) {
                err = -EINVAL;
                goto out_free;
        }

        err = proc_get_long(&p, &left, &lval, &neg,
                             proc_wspace_sep,
                             sizeof(proc_wspace_sep), NULL);
        if (err || neg) {
                err = -EINVAL;
                goto out_free;
        }

        if (conv(&lval, tbl_data, 1, data)) {
                err = -EINVAL;
                goto out_free;
        }

        if (!err && left)
                proc_skip_spaces(&p, &left);

out_free:
        if (err)
                return -EINVAL;

        return 0;

        /* This is in keeping with old __do_proc_dointvec() */
bail_early:
        *ppos += *lenp;
        return err;
}

static int do_proc_douintvec_r(unsigned int *tbl_data, void *buffer,
                               size_t *lenp, loff_t *ppos,
                               int (*conv)(unsigned long *lvalp,
                                           unsigned int *valp,
                                           int write, void *data),
                               void *data)
{
        unsigned long lval;
        int err = 0;
        size_t left;

        left = *lenp;

        if (conv(&lval, tbl_data, 0, data)) {
                err = -EINVAL;
                goto out;
        }

        proc_put_long(&buffer, &left, lval, false);
        if (!left)
                goto out;

        proc_put_char(&buffer, &left, '\n');

out:
        *lenp -= left;
        *ppos += *lenp;

        return err;
}

static int __do_proc_douintvec(void *tbl_data, struct ctl_table *table,
                               int write, void *buffer,
                               size_t *lenp, loff_t *ppos,
                               int (*conv)(unsigned long *lvalp,
                                           unsigned int *valp,
                                           int write, void *data),
                               void *data)
{
        unsigned int *i, vleft;

        if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
                *lenp = 0;
                return 0;
        }

        i = (unsigned int *) tbl_data;
        vleft = table->maxlen / sizeof(*i);

        /*
         * Arrays are not supported, keep this simple. *Do not* add
         * support for them.
         */
        if (vleft != 1) {
                *lenp = 0;
                return -EINVAL;
        }

        if (!conv)
                conv = do_proc_douintvec_conv;

        if (write)
                return do_proc_douintvec_w(i, table, buffer, lenp, ppos,
                                           conv, data);
        return do_proc_douintvec_r(i, buffer, lenp, ppos, conv, data);
}

int do_proc_douintvec(struct ctl_table *table, int write,
                      void *buffer, size_t *lenp, loff_t *ppos,
                      int (*conv)(unsigned long *lvalp,
                                  unsigned int *valp,
                                  int write, void *data),
                      void *data)
{
        return __do_proc_douintvec(table->data, table, write,
                                   buffer, lenp, ppos, conv, data);
}

/**
 * proc_dobool - read/write a bool
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes one integer value from/to the user buffer,
 * treated as an ASCII string.
 *
 * table->data must point to a bool variable and table->maxlen must
 * be sizeof(bool).
 *
 * Returns 0 on success.
 */
int proc_dobool(struct ctl_table *table, int write, void *buffer,
                size_t *lenp, loff_t *ppos)
{
        struct ctl_table tmp;
        bool *data = table->data;
        int res, val;

        /* Do not support arrays yet. */
        if (table->maxlen != sizeof(bool))
                return -EINVAL;

        tmp = *table;
        tmp.maxlen = sizeof(val);
        tmp.data = &val;

        val = READ_ONCE(*data);
        res = proc_dointvec(&tmp, write, buffer, lenp, ppos);
        if (res)
                return res;
        if (write)
                WRITE_ONCE(*data, val);
        return 0;
}

/**
 * proc_dointvec - read a vector of integers
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string.
 *
 * Returns 0 on success.
 */
int proc_dointvec(struct ctl_table *table, int write, void *buffer,
                  size_t *lenp, loff_t *ppos)
{
        return do_proc_dointvec(table, write, buffer, lenp, ppos, NULL, NULL);
}

/**
 * proc_douintvec - read a vector of unsigned integers
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
 * values from/to the user buffer, treated as an ASCII string.
 *
 * Returns 0 on success.
 */
int proc_douintvec(struct ctl_table *table, int write, void *buffer,
                size_t *lenp, loff_t *ppos)
{
        return do_proc_douintvec(table, write, buffer, lenp, ppos,
                                 do_proc_douintvec_conv, NULL);
}

/*
 * Taint values can only be increased
 * This means we can safely use a temporary.
 */
static int proc_taint(struct ctl_table *table, int write,
                               void *buffer, size_t *lenp, loff_t *ppos)
{
        struct ctl_table t;
        unsigned long tmptaint = get_taint();
        int err;

        if (write && !capable(CAP_SYS_ADMIN))
                return -EPERM;

        t = *table;
        t.data = &tmptaint;
        err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
        if (err < 0)
                return err;

        if (write) {
                int i;

                /*
                 * If we are relying on panic_on_taint not producing
                 * false positives due to userspace input, bail out
                 * before setting the requested taint flags.
                 */
                if (panic_on_taint_nousertaint && (tmptaint & panic_on_taint))
                        return -EINVAL;

                /*
                 * Poor man's atomic or. Not worth adding a primitive
                 * to everyone's atomic.h for this
                 */
                for (i = 0; i < TAINT_FLAGS_COUNT; i++)
                        if ((1UL << i) & tmptaint)
                                add_taint(i, LOCKDEP_STILL_OK);
        }

        return err;
}

/**
 * struct do_proc_dointvec_minmax_conv_param - proc_dointvec_minmax() range checking structure
 * @min: pointer to minimum allowable value
 * @max: pointer to maximum allowable value
 *
 * The do_proc_dointvec_minmax_conv_param structure provides the
 * minimum and maximum values for doing range checking for those sysctl
 * parameters that use the proc_dointvec_minmax() handler.
 */
struct do_proc_dointvec_minmax_conv_param {
        int *min;
        int *max;
};

static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
                                        int *valp,
                                        int write, void *data)
{
        int tmp, ret;
        struct do_proc_dointvec_minmax_conv_param *param = data;
        /*
         * If writing, first do so via a temporary local int so we can
         * bounds-check it before touching *valp.
         */
        int *ip = write ? &tmp : valp;

        ret = do_proc_dointvec_conv(negp, lvalp, ip, write, data);
        if (ret)
                return ret;

        if (write) {
                if ((param->min && *param->min > tmp) ||
                    (param->max && *param->max < tmp))
                        return -EINVAL;
                WRITE_ONCE(*valp, tmp);
        }

        return 0;
}

/**
 * proc_dointvec_minmax - read a vector of integers with min/max values
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string.
 *
 * This routine will ensure the values are within the range specified by
 * table->extra1 (min) and table->extra2 (max).
 *
 * Returns 0 on success or -EINVAL on write when the range check fails.
 */
int proc_dointvec_minmax(struct ctl_table *table, int write,
                  void *buffer, size_t *lenp, loff_t *ppos)
{
        struct do_proc_dointvec_minmax_conv_param param = {
                .min = (int *) table->extra1,
                .max = (int *) table->extra2,
        };
        return do_proc_dointvec(table, write, buffer, lenp, ppos,
                                do_proc_dointvec_minmax_conv, &param);
}

/**
 * struct do_proc_douintvec_minmax_conv_param - proc_douintvec_minmax() range checking structure
 * @min: pointer to minimum allowable value
 * @max: pointer to maximum allowable value
 *
 * The do_proc_douintvec_minmax_conv_param structure provides the
 * minimum and maximum values for doing range checking for those sysctl
 * parameters that use the proc_douintvec_minmax() handler.
 */
struct do_proc_douintvec_minmax_conv_param {
        unsigned int *min;
        unsigned int *max;
};

static int do_proc_douintvec_minmax_conv(unsigned long *lvalp,
                                         unsigned int *valp,
                                         int write, void *data)
{
        int ret;
        unsigned int tmp;
        struct do_proc_douintvec_minmax_conv_param *param = data;
        /* write via temporary local uint for bounds-checking */
        unsigned int *up = write ? &tmp : valp;

        ret = do_proc_douintvec_conv(lvalp, up, write, data);
        if (ret)
                return ret;

        if (write) {
                if ((param->min && *param->min > tmp) ||
                    (param->max && *param->max < tmp))
                        return -ERANGE;

                WRITE_ONCE(*valp, tmp);
        }

        return 0;
}

/**
 * proc_douintvec_minmax - read a vector of unsigned ints with min/max values
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
 * values from/to the user buffer, treated as an ASCII string. Negative
 * strings are not allowed.
 *
 * This routine will ensure the values are within the range specified by
 * table->extra1 (min) and table->extra2 (max). There is a final sanity
 * check for UINT_MAX to avoid having to support wrap around uses from
 * userspace.
 *
 * Returns 0 on success or -ERANGE on write when the range check fails.
 */
int proc_douintvec_minmax(struct ctl_table *table, int write,
                          void *buffer, size_t *lenp, loff_t *ppos)
{
        struct do_proc_douintvec_minmax_conv_param param = {
                .min = (unsigned int *) table->extra1,
                .max = (unsigned int *) table->extra2,
        };
        return do_proc_douintvec(table, write, buffer, lenp, ppos,
                                 do_proc_douintvec_minmax_conv, &param);
}

/**
 * proc_dou8vec_minmax - read a vector of unsigned chars with min/max values
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(u8) unsigned chars
 * values from/to the user buffer, treated as an ASCII string. Negative
 * strings are not allowed.
 *
 * This routine will ensure the values are within the range specified by
 * table->extra1 (min) and table->extra2 (max).
 *
 * Returns 0 on success or an error on write when the range check fails.
 */
int proc_dou8vec_minmax(struct ctl_table *table, int write,
                        void *buffer, size_t *lenp, loff_t *ppos)
{
        struct ctl_table tmp;
        unsigned int min = 0, max = 255U, val;
        u8 *data = table->data;
        struct do_proc_douintvec_minmax_conv_param param = {
                .min = &min,
                .max = &max,
        };
        int res;

        /* Do not support arrays yet. */
        if (table->maxlen != sizeof(u8))
                return -EINVAL;

        if (table->extra1) {
                min = *(unsigned int *) table->extra1;
                if (min > 255U)
                        return -EINVAL;
        }
        if (table->extra2) {
                max = *(unsigned int *) table->extra2;
                if (max > 255U)
                        return -EINVAL;
        }

        tmp = *table;

        tmp.maxlen = sizeof(val);
        tmp.data = &val;
        val = READ_ONCE(*data);
        res = do_proc_douintvec(&tmp, write, buffer, lenp, ppos,
                                do_proc_douintvec_minmax_conv, &param);
        if (res)
                return res;
        if (write)
                WRITE_ONCE(*data, val);
        return 0;
}
EXPORT_SYMBOL_GPL(proc_dou8vec_minmax);

#ifdef CONFIG_MAGIC_SYSRQ
static int sysrq_sysctl_handler(struct ctl_table *table, int write,
                                void *buffer, size_t *lenp, loff_t *ppos)
{
        int tmp, ret;

        tmp = sysrq_mask();

        ret = __do_proc_dointvec(&tmp, table, write, buffer,
                               lenp, ppos, NULL, NULL);
        if (ret || !write)
                return ret;

        if (write)
                sysrq_toggle_support(tmp);

        return 0;
}
#endif

static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table,
                int write, void *buffer, size_t *lenp, loff_t *ppos,
                unsigned long convmul, unsigned long convdiv)
{
        unsigned long *i, *min, *max;
        int vleft, first = 1, err = 0;
        size_t left;
        char *p;

        if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
                *lenp = 0;
                return 0;
        }

        i = data;
        min = table->extra1;
        max = table->extra2;
        vleft = table->maxlen / sizeof(unsigned long);
        left = *lenp;

        if (write) {
                if (proc_first_pos_non_zero_ignore(ppos, table))
                        goto out;

                if (left > PAGE_SIZE - 1)
                        left = PAGE_SIZE - 1;
                p = buffer;
        }

        for (; left && vleft--; i++, first = 0) {
                unsigned long val;

                if (write) {
                        bool neg;

                        proc_skip_spaces(&p, &left);
                        if (!left)
                                break;

                        err = proc_get_long(&p, &left, &val, &neg,
                                             proc_wspace_sep,
                                             sizeof(proc_wspace_sep), NULL);
                        if (err || neg) {
                                err = -EINVAL;
                                break;
                        }

                        val = convmul * val / convdiv;
                        if ((min && val < *min) || (max && val > *max)) {
                                err = -EINVAL;
                                break;
                        }
                        WRITE_ONCE(*i, val);
                } else {
                        val = convdiv * READ_ONCE(*i) / convmul;
                        if (!first)
                                proc_put_char(&buffer, &left, '\t');
                        proc_put_long(&buffer, &left, val, false);
                }
        }

        if (!write && !first && left && !err)
                proc_put_char(&buffer, &left, '\n');
        if (write && !err)
                proc_skip_spaces(&p, &left);
        if (write && first)
                return err ? : -EINVAL;
        *lenp -= left;
out:
        *ppos += *lenp;
        return err;
}

static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
                void *buffer, size_t *lenp, loff_t *ppos, unsigned long convmul,
                unsigned long convdiv)
{
        return __do_proc_doulongvec_minmax(table->data, table, write,
                        buffer, lenp, ppos, convmul, convdiv);
}

/**
 * proc_doulongvec_minmax - read a vector of long integers with min/max values
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
 * values from/to the user buffer, treated as an ASCII string.
 *
 * This routine will ensure the values are within the range specified by
 * table->extra1 (min) and table->extra2 (max).
 *
 * Returns 0 on success.
 */
int proc_doulongvec_minmax(struct ctl_table *table, int write,
                           void *buffer, size_t *lenp, loff_t *ppos)
{
    return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
}

/**
 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
 * values from/to the user buffer, treated as an ASCII string. The values
 * are treated as milliseconds, and converted to jiffies when they are stored.
 *
 * This routine will ensure the values are within the range specified by
 * table->extra1 (min) and table->extra2 (max).
 *
 * Returns 0 on success.
 */
int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
                                      void *buffer, size_t *lenp, loff_t *ppos)
{
    return do_proc_doulongvec_minmax(table, write, buffer,
                                     lenp, ppos, HZ, 1000l);
}


static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
                                         int *valp,
                                         int write, void *data)
{
        if (write) {
                if (*lvalp > INT_MAX / HZ)
                        return 1;
                if (*negp)
                        WRITE_ONCE(*valp, -*lvalp * HZ);
                else
                        WRITE_ONCE(*valp, *lvalp * HZ);
        } else {
                int val = READ_ONCE(*valp);
                unsigned long lval;
                if (val < 0) {
                        *negp = true;
                        lval = -(unsigned long)val;
                } else {
                        *negp = false;
                        lval = (unsigned long)val;
                }
                *lvalp = lval / HZ;
        }
        return 0;
}

static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
                                                int *valp,
                                                int write, void *data)
{
        if (write) {
                if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
                        return 1;
                *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
        } else {
                int val = *valp;
                unsigned long lval;
                if (val < 0) {
                        *negp = true;
                        lval = -(unsigned long)val;
                } else {
                        *negp = false;
                        lval = (unsigned long)val;
                }
                *lvalp = jiffies_to_clock_t(lval);
        }
        return 0;
}

static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
                                            int *valp,
                                            int write, void *data)
{
        if (write) {
                unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);

                if (jif > INT_MAX)
                        return 1;
                WRITE_ONCE(*valp, (int)jif);
        } else {
                int val = READ_ONCE(*valp);
                unsigned long lval;
                if (val < 0) {
                        *negp = true;
                        lval = -(unsigned long)val;
                } else {
                        *negp = false;
                        lval = (unsigned long)val;
                }
                *lvalp = jiffies_to_msecs(lval);
        }
        return 0;
}

static int do_proc_dointvec_ms_jiffies_minmax_conv(bool *negp, unsigned long *lvalp,
                                                int *valp, int write, void *data)
{
        int tmp, ret;
        struct do_proc_dointvec_minmax_conv_param *param = data;
        /*
         * If writing, first do so via a temporary local int so we can
         * bounds-check it before touching *valp.
         */
        int *ip = write ? &tmp : valp;

        ret = do_proc_dointvec_ms_jiffies_conv(negp, lvalp, ip, write, data);
        if (ret)
                return ret;

        if (write) {
                if ((param->min && *param->min > tmp) ||
                                (param->max && *param->max < tmp))
                        return -EINVAL;
                *valp = tmp;
        }
        return 0;
}

/**
 * proc_dointvec_jiffies - read a vector of integers as seconds
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string.
 * The values read are assumed to be in seconds, and are converted into
 * jiffies.
 *
 * Returns 0 on success.
 */
int proc_dointvec_jiffies(struct ctl_table *table, int write,
                          void *buffer, size_t *lenp, loff_t *ppos)
{
    return do_proc_dointvec(table,write,buffer,lenp,ppos,
                            do_proc_dointvec_jiffies_conv,NULL);
}

int proc_dointvec_ms_jiffies_minmax(struct ctl_table *table, int write,
                          void *buffer, size_t *lenp, loff_t *ppos)
{
        struct do_proc_dointvec_minmax_conv_param param = {
                .min = (int *) table->extra1,
                .max = (int *) table->extra2,
        };
        return do_proc_dointvec(table, write, buffer, lenp, ppos,
                        do_proc_dointvec_ms_jiffies_minmax_conv, &param);
}

/**
 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: pointer to the file position
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string.
 * The values read are assumed to be in 1/USER_HZ seconds, and
 * are converted into jiffies.
 *
 * Returns 0 on success.
 */
int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
                                 void *buffer, size_t *lenp, loff_t *ppos)
{
        return do_proc_dointvec(table, write, buffer, lenp, ppos,
                                do_proc_dointvec_userhz_jiffies_conv, NULL);
}

/**
 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 * @ppos: the current position in the file
 *
 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
 * values from/to the user buffer, treated as an ASCII string.
 * The values read are assumed to be in 1/1000 seconds, and
 * are converted into jiffies.
 *
 * Returns 0 on success.
 */
int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, void *buffer,
                size_t *lenp, loff_t *ppos)
{
        return do_proc_dointvec(table, write, buffer, lenp, ppos,
                                do_proc_dointvec_ms_jiffies_conv, NULL);
}

static int proc_do_cad_pid(struct ctl_table *table, int write, void *buffer,
                size_t *lenp, loff_t *ppos)
{
        struct pid *new_pid;
        pid_t tmp;
        int r;

        tmp = pid_vnr(cad_pid);

        r = __do_proc_dointvec(&tmp, table, write, buffer,
                               lenp, ppos, NULL, NULL);
        if (r || !write)
                return r;

        new_pid = find_get_pid(tmp);
        if (!new_pid)
                return -ESRCH;

        put_pid(xchg(&cad_pid, new_pid));
        return 0;
}

/**
 * proc_do_large_bitmap - read/write from/to a large bitmap
 * @table: the sysctl table
 * @write: %TRUE if this is a write to the sysctl file
 * @buffer: the user buffer
 * @lenp: the size of the user buffer
 * @ppos: file position
 *
 * The bitmap is stored at table->data and the bitmap length (in bits)
 * in table->maxlen.
 *
 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
 * large bitmaps may be represented in a compact manner. Writing into
 * the file will clear the bitmap then update it with the given input.
 *
 * Returns 0 on success.
 */
int proc_do_large_bitmap(struct ctl_table *table, int write,
                         void *buffer, size_t *lenp, loff_t *ppos)
{
        int err = 0;
        size_t left = *lenp;
        unsigned long bitmap_len = table->maxlen;
        unsigned long *bitmap = *(unsigned long **) table->data;
        unsigned long *tmp_bitmap = NULL;
        char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;

        if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
                *lenp = 0;
                return 0;
        }

        if (write) {
                char *p = buffer;
                size_t skipped = 0;

                if (left > PAGE_SIZE - 1) {
                        left = PAGE_SIZE - 1;
                        /* How much of the buffer we'll skip this pass */
                        skipped = *lenp - left;
                }

                tmp_bitmap = bitmap_zalloc(bitmap_len, GFP_KERNEL);
                if (!tmp_bitmap)
                        return -ENOMEM;
                proc_skip_char(&p, &left, '\n');
                while (!err && left) {
                        unsigned long val_a, val_b;
                        bool neg;
                        size_t saved_left;

                        /* In case we stop parsing mid-number, we can reset */
                        saved_left = left;
                        err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
                                             sizeof(tr_a), &c);
                        /*
                         * If we consumed the entirety of a truncated buffer or
                         * only one char is left (may be a "-"), then stop here,
                         * reset, & come back for more.
                         */
                        if ((left <= 1) && skipped) {
                                left = saved_left;
                                break;
                        }

                        if (err)
                                break;
                        if (val_a >= bitmap_len || neg) {
                                err = -EINVAL;
                                break;
                        }

                        val_b = val_a;
                        if (left) {
                                p++;
                                left--;
                        }

                        if (c == '-') {
                                err = proc_get_long(&p, &left, &val_b,
                                                     &neg, tr_b, sizeof(tr_b),
                                                     &c);
                                /*
                                 * If we consumed all of a truncated buffer or
                                 * then stop here, reset, & come back for more.
                                 */
                                if (!left && skipped) {
                                        left = saved_left;
                                        break;
                                }

                                if (err)
                                        break;
                                if (val_b >= bitmap_len || neg ||
                                    val_a > val_b) {
                                        err = -EINVAL;
                                        break;
                                }
                                if (left) {
                                        p++;
                                        left--;
                                }
                        }

                        bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
                        proc_skip_char(&p, &left, '\n');
                }
                left += skipped;
        } else {
                unsigned long bit_a, bit_b = 0;
                bool first = 1;

                while (left) {
                        bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
                        if (bit_a >= bitmap_len)
                                break;
                        bit_b = find_next_zero_bit(bitmap, bitmap_len,
                                                   bit_a + 1) - 1;

                        if (!first)
                                proc_put_char(&buffer, &left, ',');
                        proc_put_long(&buffer, &left, bit_a, false);
                        if (bit_a != bit_b) {
                                proc_put_char(&buffer, &left, '-');
                                proc_put_long(&buffer, &left, bit_b, false);
                        }

                        first = 0; bit_b++;
                }
                proc_put_char(&buffer, &left, '\n');
        }

        if (!err) {
                if (write) {
                        if (*ppos)
                                bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
                        else
                                bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
                }
                *lenp -= left;
                *ppos += *lenp;
        }

        bitmap_free(tmp_bitmap);
        return err;
}

#else /* CONFIG_PROC_SYSCTL */

int proc_dostring(struct ctl_table *table, int write,
                  void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_dobool(struct ctl_table *table, int write,
                void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_dointvec(struct ctl_table *table, int write,
                  void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_douintvec(struct ctl_table *table, int write,
                  void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_dointvec_minmax(struct ctl_table *table, int write,
                    void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_douintvec_minmax(struct ctl_table *table, int write,
                          void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_dou8vec_minmax(struct ctl_table *table, int write,
                        void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_dointvec_jiffies(struct ctl_table *table, int write,
                    void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_dointvec_ms_jiffies_minmax(struct ctl_table *table, int write,
                                    void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
                    void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
                             void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_doulongvec_minmax(struct ctl_table *table, int write,
                    void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
                                      void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

int proc_do_large_bitmap(struct ctl_table *table, int write,
                         void *buffer, size_t *lenp, loff_t *ppos)
{
        return -ENOSYS;
}

#endif /* CONFIG_PROC_SYSCTL */

#if defined(CONFIG_SYSCTL)
int proc_do_static_key(struct ctl_table *table, int write,
                       void *buffer, size_t *lenp, loff_t *ppos)
{
        struct static_key *key = (struct static_key *)table->data;
        static DEFINE_MUTEX(static_key_mutex);
        int val, ret;
        struct ctl_table tmp = {
                .data   = &val,
                .maxlen = sizeof(val),
                .mode   = table->mode,
                .extra1 = SYSCTL_ZERO,
                .extra2 = SYSCTL_ONE,
        };

        if (write && !capable(CAP_SYS_ADMIN))
                return -EPERM;

        mutex_lock(&static_key_mutex);
        val = static_key_enabled(key);
        ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
        if (write && !ret) {
                if (val)
                        static_key_enable(key);
                else
                        static_key_disable(key);
        }
        mutex_unlock(&static_key_mutex);
        return ret;
}

static struct ctl_table kern_table[] = {
        {
                .procname       = "panic",
                .data           = &panic_timeout,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#ifdef CONFIG_PROC_SYSCTL
        {
                .procname       = "tainted",
                .maxlen         = sizeof(long),
                .mode           = 0644,
                .proc_handler   = proc_taint,
        },
        {
                .procname       = "sysctl_writes_strict",
                .data           = &sysctl_writes_strict,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_NEG_ONE,
                .extra2         = SYSCTL_ONE,
        },
#endif
        {
                .procname       = "print-fatal-signals",
                .data           = &print_fatal_signals,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#ifdef CONFIG_SPARC
        {
                .procname       = "reboot-cmd",
                .data           = reboot_command,
                .maxlen         = 256,
                .mode           = 0644,
                .proc_handler   = proc_dostring,
        },
        {
                .procname       = "stop-a",
                .data           = &stop_a_enabled,
                .maxlen         = sizeof (int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "scons-poweroff",
                .data           = &scons_pwroff,
                .maxlen         = sizeof (int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif
#ifdef CONFIG_SPARC64
        {
                .procname       = "tsb-ratio",
                .data           = &sysctl_tsb_ratio,
                .maxlen         = sizeof (int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif
#ifdef CONFIG_PARISC
        {
                .procname       = "soft-power",
                .data           = &pwrsw_enabled,
                .maxlen         = sizeof (int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif
#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
        {
                .procname       = "unaligned-trap",
                .data           = &unaligned_enabled,
                .maxlen         = sizeof (int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif
#ifdef CONFIG_STACK_TRACER
        {
                .procname       = "stack_tracer_enabled",
                .data           = &stack_tracer_enabled,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = stack_trace_sysctl,
        },
#endif
#ifdef CONFIG_TRACING
        {
                .procname       = "ftrace_dump_on_oops",
                .data           = &ftrace_dump_on_oops,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "traceoff_on_warning",
                .data           = &__disable_trace_on_warning,
                .maxlen         = sizeof(__disable_trace_on_warning),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "tracepoint_printk",
                .data           = &tracepoint_printk,
                .maxlen         = sizeof(tracepoint_printk),
                .mode           = 0644,
                .proc_handler   = tracepoint_printk_sysctl,
        },
#endif
#ifdef CONFIG_MODULES
        {
                .procname       = "modprobe",
                .data           = &modprobe_path,
                .maxlen         = KMOD_PATH_LEN,
                .mode           = 0644,
                .proc_handler   = proc_dostring,
        },
        {
                .procname       = "modules_disabled",
                .data           = &modules_disabled,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                /* only handle a transition from default "0" to "1" */
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ONE,
                .extra2         = SYSCTL_ONE,
        },
#endif
#ifdef CONFIG_UEVENT_HELPER
        {
                .procname       = "hotplug",
                .data           = &uevent_helper,
                .maxlen         = UEVENT_HELPER_PATH_LEN,
                .mode           = 0644,
                .proc_handler   = proc_dostring,
        },
#endif
#ifdef CONFIG_MAGIC_SYSRQ
        {
                .procname       = "sysrq",
                .data           = NULL,
                .maxlen         = sizeof (int),
                .mode           = 0644,
                .proc_handler   = sysrq_sysctl_handler,
        },
#endif
#ifdef CONFIG_PROC_SYSCTL
        {
                .procname       = "cad_pid",
                .data           = NULL,
                .maxlen         = sizeof (int),
                .mode           = 0600,
                .proc_handler   = proc_do_cad_pid,
        },
#endif
        {
                .procname       = "threads-max",
                .data           = NULL,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = sysctl_max_threads,
        },
        {
                .procname       = "overflowuid",
                .data           = &overflowuid,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_MAXOLDUID,
        },
        {
                .procname       = "overflowgid",
                .data           = &overflowgid,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_MAXOLDUID,
        },
#ifdef CONFIG_S390
        {
                .procname       = "userprocess_debug",
                .data           = &show_unhandled_signals,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif
        {
                .procname       = "pid_max",
                .data           = &pid_max,
                .maxlen         = sizeof (int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = &pid_max_min,
                .extra2         = &pid_max_max,
        },
        {
                .procname       = "panic_on_oops",
                .data           = &panic_on_oops,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "panic_print",
                .data           = &panic_print,
                .maxlen         = sizeof(unsigned long),
                .mode           = 0644,
                .proc_handler   = proc_doulongvec_minmax,
        },
        {
                .procname       = "ngroups_max",
                .data           = (void *)&ngroups_max,
                .maxlen         = sizeof (int),
                .mode           = 0444,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "cap_last_cap",
                .data           = (void *)&cap_last_cap,
                .maxlen         = sizeof(int),
                .mode           = 0444,
                .proc_handler   = proc_dointvec,
        },
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
        {
                .procname       = "unknown_nmi_panic",
                .data           = &unknown_nmi_panic,
                .maxlen         = sizeof (int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif

#if (defined(CONFIG_X86_32) || defined(CONFIG_PARISC)) && \
        defined(CONFIG_DEBUG_STACKOVERFLOW)
        {
                .procname       = "panic_on_stackoverflow",
                .data           = &sysctl_panic_on_stackoverflow,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif
#if defined(CONFIG_X86)
        {
                .procname       = "panic_on_unrecovered_nmi",
                .data           = &panic_on_unrecovered_nmi,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "panic_on_io_nmi",
                .data           = &panic_on_io_nmi,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "bootloader_type",
                .data           = &bootloader_type,
                .maxlen         = sizeof (int),
                .mode           = 0444,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "bootloader_version",
                .data           = &bootloader_version,
                .maxlen         = sizeof (int),
                .mode           = 0444,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "io_delay_type",
                .data           = &io_delay_type,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif
#if defined(CONFIG_MMU)
        {
                .procname       = "randomize_va_space",
                .data           = &randomize_va_space,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif
#if defined(CONFIG_S390) && defined(CONFIG_SMP)
        {
                .procname       = "spin_retry",
                .data           = &spin_retry,
                .maxlen         = sizeof (int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif
#if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
        {
                .procname       = "acpi_video_flags",
                .data           = &acpi_realmode_flags,
                .maxlen         = sizeof (unsigned long),
                .mode           = 0644,
                .proc_handler   = proc_doulongvec_minmax,
        },
#endif
#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
        {
                .procname       = "ignore-unaligned-usertrap",
                .data           = &no_unaligned_warning,
                .maxlen         = sizeof (int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif
#ifdef CONFIG_RT_MUTEXES
        {
                .procname       = "max_lock_depth",
                .data           = &max_lock_depth,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
#endif
#ifdef CONFIG_PERF_EVENTS
        /*
         * User-space scripts rely on the existence of this file
         * as a feature check for perf_events being enabled.
         *
         * So it's an ABI, do not remove!
         */
        {
                .procname       = "perf_event_paranoid",
                .data           = &sysctl_perf_event_paranoid,
                .maxlen         = sizeof(sysctl_perf_event_paranoid),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "perf_event_mlock_kb",
                .data           = &sysctl_perf_event_mlock,
                .maxlen         = sizeof(sysctl_perf_event_mlock),
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
        },
        {
                .procname       = "perf_event_max_sample_rate",
                .data           = &sysctl_perf_event_sample_rate,
                .maxlen         = sizeof(sysctl_perf_event_sample_rate),
                .mode           = 0644,
                .proc_handler   = perf_event_max_sample_rate_handler,
                .extra1         = SYSCTL_ONE,
        },
        {
                .procname       = "perf_cpu_time_max_percent",
                .data           = &sysctl_perf_cpu_time_max_percent,
                .maxlen         = sizeof(sysctl_perf_cpu_time_max_percent),
                .mode           = 0644,
                .proc_handler   = perf_cpu_time_max_percent_handler,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE_HUNDRED,
        },
        {
                .procname       = "perf_event_max_stack",
                .data           = &sysctl_perf_event_max_stack,
                .maxlen         = sizeof(sysctl_perf_event_max_stack),
                .mode           = 0644,
                .proc_handler   = perf_event_max_stack_handler,
                .extra1         = SYSCTL_ZERO,
                .extra2         = (void *)&six_hundred_forty_kb,
        },
        {
                .procname       = "perf_event_max_contexts_per_stack",
                .data           = &sysctl_perf_event_max_contexts_per_stack,
                .maxlen         = sizeof(sysctl_perf_event_max_contexts_per_stack),
                .mode           = 0644,
                .proc_handler   = perf_event_max_stack_handler,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE_THOUSAND,
        },
#endif
        {
                .procname       = "panic_on_warn",
                .data           = &panic_on_warn,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
#ifdef CONFIG_TREE_RCU
        {
                .procname       = "panic_on_rcu_stall",
                .data           = &sysctl_panic_on_rcu_stall,
                .maxlen         = sizeof(sysctl_panic_on_rcu_stall),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
        {
                .procname       = "max_rcu_stall_to_panic",
                .data           = &sysctl_max_rcu_stall_to_panic,
                .maxlen         = sizeof(sysctl_max_rcu_stall_to_panic),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ONE,
                .extra2         = SYSCTL_INT_MAX,
        },
#endif
        { }
};

static struct ctl_table vm_table[] = {
        {
                .procname       = "overcommit_memory",
                .data           = &sysctl_overcommit_memory,
                .maxlen         = sizeof(sysctl_overcommit_memory),
                .mode           = 0644,
                .proc_handler   = overcommit_policy_handler,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_TWO,
        },
        {
                .procname       = "overcommit_ratio",
                .data           = &sysctl_overcommit_ratio,
                .maxlen         = sizeof(sysctl_overcommit_ratio),
                .mode           = 0644,
                .proc_handler   = overcommit_ratio_handler,
        },
        {
                .procname       = "overcommit_kbytes",
                .data           = &sysctl_overcommit_kbytes,
                .maxlen         = sizeof(sysctl_overcommit_kbytes),
                .mode           = 0644,
                .proc_handler   = overcommit_kbytes_handler,
        },
        {
                .procname       = "page-cluster",
                .data           = &page_cluster,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = (void *)&page_cluster_max,
        },
        {
                .procname       = "dirtytime_expire_seconds",
                .data           = &dirtytime_expire_interval,
                .maxlen         = sizeof(dirtytime_expire_interval),
                .mode           = 0644,
                .proc_handler   = dirtytime_interval_handler,
                .extra1         = SYSCTL_ZERO,
        },
        {
                .procname       = "swappiness",
                .data           = &vm_swappiness,
                .maxlen         = sizeof(vm_swappiness),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_TWO_HUNDRED,
        },
#ifdef CONFIG_NUMA
        {
                .procname       = "numa_stat",
                .data           = &sysctl_vm_numa_stat,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = sysctl_vm_numa_stat_handler,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_ONE,
        },
#endif
        {
                .procname       = "drop_caches",
                .data           = &sysctl_drop_caches,
                .maxlen         = sizeof(int),
                .mode           = 0200,
                .proc_handler   = drop_caches_sysctl_handler,
                .extra1         = SYSCTL_ONE,
                .extra2         = SYSCTL_FOUR,
        },
        {
                .procname       = "page_lock_unfairness",
                .data           = &sysctl_page_lock_unfairness,
                .maxlen         = sizeof(sysctl_page_lock_unfairness),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
        },
#ifdef CONFIG_MMU
        {
                .procname       = "max_map_count",
                .data           = &sysctl_max_map_count,
                .maxlen         = sizeof(sysctl_max_map_count),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
        },
#else
        {
                .procname       = "nr_trim_pages",
                .data           = &sysctl_nr_trim_pages,
                .maxlen         = sizeof(sysctl_nr_trim_pages),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
        },
#endif
        {
                .procname       = "vfs_cache_pressure",
                .data           = &sysctl_vfs_cache_pressure,
                .maxlen         = sizeof(sysctl_vfs_cache_pressure),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
        },
#if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \
    defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT)
        {
                .procname       = "legacy_va_layout",
                .data           = &sysctl_legacy_va_layout,
                .maxlen         = sizeof(sysctl_legacy_va_layout),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
        },
#endif
#ifdef CONFIG_NUMA
        {
                .procname       = "zone_reclaim_mode",
                .data           = &node_reclaim_mode,
                .maxlen         = sizeof(node_reclaim_mode),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
        },
#endif
#ifdef CONFIG_SMP
        {
                .procname       = "stat_interval",
                .data           = &sysctl_stat_interval,
                .maxlen         = sizeof(sysctl_stat_interval),
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
        {
                .procname       = "stat_refresh",
                .data           = NULL,
                .maxlen         = 0,
                .mode           = 0600,
                .proc_handler   = vmstat_refresh,
        },
#endif
#ifdef CONFIG_MMU
        {
                .procname       = "mmap_min_addr",
                .data           = &dac_mmap_min_addr,
                .maxlen         = sizeof(unsigned long),
                .mode           = 0644,
                .proc_handler   = mmap_min_addr_handler,
        },
#endif
#if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
   (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
        {
                .procname       = "vdso_enabled",
#ifdef CONFIG_X86_32
                .data           = &vdso32_enabled,
                .maxlen         = sizeof(vdso32_enabled),
#else
                .data           = &vdso_enabled,
                .maxlen         = sizeof(vdso_enabled),
#endif
                .mode           = 0644,
                .proc_handler   = proc_dointvec,
                .extra1         = SYSCTL_ZERO,
        },
#endif
        {
                .procname       = "user_reserve_kbytes",
                .data           = &sysctl_user_reserve_kbytes,
                .maxlen         = sizeof(sysctl_user_reserve_kbytes),
                .mode           = 0644,
                .proc_handler   = proc_doulongvec_minmax,
        },
        {
                .procname       = "admin_reserve_kbytes",
                .data           = &sysctl_admin_reserve_kbytes,
                .maxlen         = sizeof(sysctl_admin_reserve_kbytes),
                .mode           = 0644,
                .proc_handler   = proc_doulongvec_minmax,
        },
#ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
        {
                .procname       = "mmap_rnd_bits",
                .data           = &mmap_rnd_bits,
                .maxlen         = sizeof(mmap_rnd_bits),
                .mode           = 0600,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = (void *)&mmap_rnd_bits_min,
                .extra2         = (void *)&mmap_rnd_bits_max,
        },
#endif
#ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
        {
                .procname       = "mmap_rnd_compat_bits",
                .data           = &mmap_rnd_compat_bits,
                .maxlen         = sizeof(mmap_rnd_compat_bits),
                .mode           = 0600,
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = (void *)&mmap_rnd_compat_bits_min,
                .extra2         = (void *)&mmap_rnd_compat_bits_max,
        },
#endif
        { }
};

int __init sysctl_init_bases(void)
{
        register_sysctl_init("kernel", kern_table);
        register_sysctl_init("vm", vm_table);

        return 0;
}
#endif /* CONFIG_SYSCTL */
/*
 * No sense putting this after each symbol definition, twice,
 * exception granted :-)
 */
EXPORT_SYMBOL(proc_dobool);
EXPORT_SYMBOL(proc_dointvec);
EXPORT_SYMBOL(proc_douintvec);
EXPORT_SYMBOL(proc_dointvec_jiffies);
EXPORT_SYMBOL(proc_dointvec_minmax);
EXPORT_SYMBOL_GPL(proc_douintvec_minmax);
EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
EXPORT_SYMBOL(proc_dostring);
EXPORT_SYMBOL(proc_doulongvec_minmax);
EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
EXPORT_SYMBOL(proc_do_large_bitmap);