Hi, On Tue, May 7, 2019 at 3:17 PM Frank Rowand <frowand.list@xxxxxxxxx> wrote: > > 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? Sure, there are a million different ways to slice it. If you prefer that instead of adding a dummy of_node_is_root() I'm happy to do that. -Doug _______________________________________________ Linux-rockchip mailing list Linux-rockchip@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-rockchip
