reduced testcase

testcase.c (text/plain), 1.72 KB, created by Diego Elio Pettenò (RETIRED) on 2010-09-06 21:48:39 UTC

#define _GNU_SOURCE

#include <limits.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <stdio.h>
#include <string.h>

/* list of maps, that are unconditionaly ignored */
static const char * const _ignore_maps[] = {
    "[vdso]",
    "[vsyscall]",
    "locale/locale-archive",
    "gconv/gconv-modules.cache",
};

/*
 * mlock/munlock memory areas from /proc/self/maps
 * format described in kernel/Documentation/filesystem/proc.txt
 */
static void _maps_line(const char* line)
{
  const struct config_node *cn;
  struct config_value *cv;
  long from, to;
  int pos, i;
  char fr, fw, fx, fp;
  size_t sz;

  if (sscanf(line, "%lx-%lx %c%c%c%c%n",
             &from, &to, &fr, &fw, &fx, &fp, &pos) != 6) {
    fprintf(stderr, "Failed to parse maps line: %s\n", line);
    return;
  }

  if (fr != 'r') {
    fprintf(stderr, "mlock area unreadable %s : Skipping.\n",
            line);
    return;
  }

  for (i = 0; i < sizeof(_ignore_maps) / sizeof(_ignore_maps[0]); ++i)
    if (strstr(line + pos, _ignore_maps[i])) {
      fprintf(stderr, "mlock ignore filter '%s' matches '%s': Skipping.\n",
                _ignore_maps[i], line);
      return;
    }

  sz = to - from;

  fprintf(stderr, "mlock %10ldKiB %12lx - %12lx %c%c%c%c%s\n",
            ((long)sz + 1023) / 1024, from, to, fr, fw, fx, fp, line + pos);

  if (mlock((const void*)from, sz) < 0) {
    perror("mlock");
    return;
  }

  return;
}

int main()
{
  FILE *_mapsh;
  ssize_t n;
  size_t len;
	char *line = NULL;

  if ( !(_mapsh = fopen("/proc/self/maps", "r")) )
    return -1;

  while ((n = getline(&line, &len, _mapsh)) != -1) {
    line[n > 0 ? n - 1 : 0] = '\0'; /* remove \n */
    _maps_line(line);
  }
}