master/src/sigar_util.c/sigar_file2str would be running out of memory when len equal to 8192

[hubzhangxj]

int sigar_file2str(const char *fname, char *buffer, int buflen)
{
int len, status;
int fd = open(fname, O_RDONLY);

if (fd < 0) {
    return ENOENT;
}

if ((len = read(fd, buffer, buflen)) < 0) {
    status = errno;
}
else {
    status = SIGAR_OK;
   /* buffer[len] = '\0'; is bug？ */
    buffer[len - 1] = '\0';
}
close(fd);

return status;

}

[hubzhangxj]

linux fd（PROC_STAT）equal to 8192,
Linux platform
stdio.h:# define BUFSIZ _IO_BUFSIZ
libio.h:#define _IO_BUFSIZ _G_BUFSIZ
_G_config.h:#define _G_BUFSIZ 8192