On 5/6/19 4:58 PM, Doug Anderson wrote: > Hi, > > On Mon, May 6, 2019 at 2:10 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote: >> >> From: Douglas Anderson <dianders@xxxxxxxxxxxx> >> Date: Fri, May 3, 2019 at 10:48 AM >> To: Kees Cook, Anton Vorontsov >> Cc: <linux-rockchip@xxxxxxxxxxxxxxxxxxx>, <jwerner@xxxxxxxxxxxx>, >> <groeck@xxxxxxxxxxxx>, <mka@xxxxxxxxxxxx>, <briannorris@xxxxxxxxxxxx>, >> Douglas Anderson, Colin Cross, Tony Luck, >> <linux-kernel@xxxxxxxxxxxxxxx> >> >>> When you try to run an upstream kernel on an old ARM-based Chromebook >>> you'll find that console-ramoops doesn't work. >>> >>> Old ARM-based Chromebooks, before <https://crrev.com/c/439792> >>> ("ramoops: support upstream {console,pmsg,ftrace}-size properties") >>> used to create a "ramoops" node at the top level that looked like: >>> >>> / { >>> ramoops { >>> compatible = "ramoops"; >>> reg = <...>; >>> record-size = <...>; >>> dump-oops; >>> }; >>> }; >>> >>> ...and these Chromebooks assumed that the downstream kernel would make >>> console_size / pmsg_size match the record size. The above ramoops >>> node was added by the firmware so it's not easy to make any changes. >>> >>> Let's match the expected behavior, but only for those using the old >>> backward-compatible way of working where ramoops is right under the >>> root node. >>> >>> NOTE: if there are some out-of-tree devices that had ramoops at the >>> top level, left everything but the record size as 0, and somehow >>> doesn't want this behavior, we can try to add more conditions here. >>> >>> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> >> >> I like this; thanks! Rob is this okay by you? I just want to >> double-check since it's part of the DT parsing logic. >> >> I'll pick it up and add a Cc: stable. > > Hold off a second--I may need to send out a v2 but out of time for the > day. I think I need a #include file to fix errors on x86: > >> implicit declaration of function 'of_node_is_root' [-Werror,-Wimplicit-function-declaration Instead of checking "of_node_is_root(parent_node)" the patch could check for parent_node not "/reserved-memory". Then the x86 error would not occur. The check I am suggesting is not as precise, but it should be good enough for this case, correct? -Frank > > I'm unfortunately out of time for now, but I'll post a v2 within the next day. > > > -Doug > _______________________________________________ Linux-rockchip mailing list Linux-rockchip@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-rockchip
