Hi Frank,
On Sat, Dec 9, 2017 at 7:01 AM, Frank Rowand <frowand.list@xxxxxxxxx> wrote:
> On 12/08/17 05:13, Geert Uytterhoeven wrote:
>> This patch series fixes memory corruption when applying overlays.
>> I first noticed this when using OF configfs. After lots of failed
>> debugging attempts, I bisected it to "of: overlay: add per overlay sysfs
>> attributes", which is not upstream. But that was a red herring: that
>> commit enlarged struct fragment to exactly 64-bytes, which just made it
>> more likely to cause random corruption when writing beyond the end of an
>> array of fragment structures. With the smaller structure size before,
>> such writes usually ended up in the unused holes between allocated
>> blocks, causing no harm.
>>
>> The first patch is the real fix, and applies to both v4.15-rc2 and Rob's
>> for-next branch.
>> The second patch is a small improvement, and applies to Rob's for-next
>> branch only.
>
> Overlay FDT files should not have invalid contents. But they inevitably
> will, so the code has to handle those cases. Thanks for finding this
> problem and making the code better!
Sure, people can throw anything at it ;-)
In my case, I'm wondering if the dtbo was actually invalid?
Simplification of the decompiled dtbo:
/dts-v1/;
/ {
fragment-name {
target-path = [2f 00];
__overlay__ {
node-name {
compatible = "foo,bar";
gpios = <0xffffffff 0x0 0x0>;
};
};
};
__fixups__ {
bank0 = "/fragment-name/__overlay__/node-name:gpios:0";
};
};
So it has __fixup__, but no __symbols__, which looks totally valid to me.
> For the full series:
>
> Reviewed-by: Frank Rowand <frank.rowand@xxxxxxxx>
Thanks!
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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