[PATCH] kbuild: modpost: Warn about references from rodata to __init text

On Fri, Jun 30, 2017 at 6:58 PM, Stephen Boyd [off-list ref] wrote:

If we have a structure that's marked const it will be placed
into the .rodata section but it could reference an init section
function. Include the read only data section in the check we have
for read/write data sections referencing init sections so we can
find this class of problems. This exposes quite a few places
where const marked structures are referencing __init functions and
__init data that we were previously ignoring.

Cc: Rob Clark <redacted>
Cc: Bjorn Andersson <redacted>
Signed-off-by: Stephen Boyd <redacted>
---

Making this change leads to quite a few other errors even on the
multi_v7_defconfig for ARM[1]. I still need to do a build of the
allmodconfig to see how many other errors there, but it seems to
be quite a few. I suppose those will need to be fixed before we can
merge this?

thanks.. the explosions you get with these mistakes when building
drivers as modules in a distro kernel config are quite "fun" to
debug..

I'm not quite sure about the rules for whether merging this would
count as a regression, but I would argue those drivers are already
broken, just no one noticed yet.  Similar to when a new gcc gets more
clever about detecting bugs.  So I wouldn't be against merging this
first to force drivers to fix their crap ;-)

BR,
-R