• Wladislav Wiebe's avatar
    of: fdt: fix memory initialization for expanded DT · abcdf87c
    Wladislav Wiebe authored
    commit 9e40127526e857fa3f29d51e83277204fbdfc6ba upstream.
    
    Already existing property flags are filled wrong for properties created from
    initial FDT. This could cause problems if this DYNAMIC device-tree functions
    are used later, i.e. properties are attached/detached/replaced. Simply dumping
    flags from the running system show, that some initial static (not allocated via
    kzmalloc()) nodes are marked as dynamic.
    
    I putted some debug extensions to property_proc_show(..) :
    ..
    +       if (OF_IS_DYNAMIC(pp))
    +               pr_err("DEBUG: xxx : OF_IS_DYNAMIC\n");
    +       if (OF_IS_DETACHED(pp))
    +               pr_err("DEBUG: xxx : OF_IS_DETACHED\n");
    
    when you operate on the nodes (e.g.: ~$ cat /proc/device-tree/*some_node*) you
    will see that those flags are filled wrong, basically in most cases it will dump
    a DYNAMIC or DETACHED status, which is in not true.
    (BTW. this OF_IS_DETACHED is a own define for debug purposes which which just
    make a test_bit(OF_DETACHED, &x->_flags)
    
    If nodes are dynamic kernel is allowed to kfree() them. But it will crash
    attempting to do so on the nodes from FDT -- they are not allocated via
    kzmalloc().
    Signed-off-by: default avatarWladislav Wiebe <wladislav.kw@gmail.com>
    Acked-by: default avatarAlexander Sverdlin <alexander.sverdlin@nsn.com>
    Signed-off-by: default avatarRob Herring <rob.herring@calxeda.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    abcdf87c
fdt.c 18.1 KB