On Mon, Nov 11, 2019 at 10:04:42AM +0200, Stefan Mavrodiev wrote:
> When libfdt applies overlay, which has aliases, they are added to
> the __symbols__ node. Since the overlay path is string, it ends with
> trailing zero. However, when calculating path length, this symbol should
> be excluded. The effect is, that the property is treated as integer
> instead of string.
Applied, thanks.
>
> Here is a simple example. Using test/overlay_base:
> / {
> test-node {
> ...
> };
> __symbols__ {
> test = "/test-node";
> ...
> };
> };
>
> Compaling simple overlay with alias node:
> / {
> fragment@0 {
> target = <0xffffffff>;
> __overlay__ {
> foo {
> bar = "bar";
> phandle = <0x00000001>;
> };
> };
> };
> __symbols__ {
> foo = "/fragment@0/__overlay__/foo";
> };
> __fixups__ {
> test = "/fragment@0:target:0";
> };
> };
>
> After merge:
> / {
> ...
> __symbols__ {
> foo = <0x2f746573 0x742d6e6f 0x64652f66 0x6f6f0000>;
> ...
> };
> };
>
> You can see that the foo value is wrong. It's parsed as int, instead of string. Same
> test with the fix:
>
> / {
> ...
> __symbols__ {
> foo = "/test-node/foo";
> ...
> };
> };
>
> The test-case uses already existing overlays:
> - stacked_overlay_bar.dts
> - stacked_overlay_baz.dts
>
> When comparing existing with actual, the string seems the same, however there is extra character in the end.
> This can be seen with hexdump. Thus an error is returned.
>
> Changes in v2:
> - Add test-case
>
> Stefan Mavrodiev (2):
> Remove trailing zero from the overlay path
> Add test-case for trailing zero
>
> libfdt/fdt_overlay.c | 2 +-
> tests/run_tests.sh | 4 ++++
> 2 files changed, 5 insertions(+), 1 deletion(-)
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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