Re: [PATCH 4.14 000/159] 4.14.9-stable review

From: Andre Tomt
Date: Sun Dec 24 2017 - 17:14:06 EST

On 24. des. 2017 20:37, Ivan Kozik wrote:
On Fri, Dec 22, 2017 at 8:44 AM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
This is the start of the stable review cycle for the 4.14.9 release.
There are 159 patches in this series, all will be posted as a response
to this one. If anyone has any issues with these being applied, please
let me know.

Responses should be made by Sun Dec 24 08:45:36 UTC 2017.
Anything received after that time might be too late.

Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
x86/unwind: Make CONFIG_UNWINDER_ORC=y the default in kconfig for 64-bit

This is uncovering a very difficult-to-debug build failure with NVIDIA DKMS:
with CONFIG_UNWINDER_ORC=y, out-of-tree modules hit this rule in

$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE

and fail (here, at least) to build tools/objtool/objtool (note: I do have
libelf-dev installed)

After editing dkms.conf to do `make --debug=a -j1`, I see make output:

Considering target file
File '/var/lib/dkms/nvidia-current/387.34/build/nvidia/nv-gpu-numa.o'
does not exist.
Looking for an implicit rule for
Trying rule prerequisite 'tools/objtool/objtool'.
Looking for a rule with intermediate file 'tools/objtool/objtool'.
Avoiding implicit rule recursion.

then silently fail to build objtool, silently fail to build all the .o files,
then continue until ld finally errors out trying to link nonexistent object

If things look alright to you, and objtool is known to work with out-of-tree
modules, and the Debian packaging just needs to be adjusted, please ignore;
I figured I'd send this anyway because it was such a pain to debug.

The linux-header packages dkms builds against need to include objtool when the ORC unwinder is enabled.

Changing the default like that is a pretty big change for a stable release.