Subject: linux-next: build failure after merge of the ecryptfs tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 14 May 2019 10:15:18 +1000

Hi all,

I don't know why this suddenly appeared after mergeing the ecryptfs tree
since nothin has changed in that tree for some time (and nothing in that
tree seems relevant).

After merging the ecryptfs tree, today's linux-next build (x86_64
allmodconfig) failed like this:

scripts/Makefile.modpost:112: target '.tmp_versions/asix.mod' doesn't match the target pattern
scripts/Makefile.modpost:113: warning: overriding recipe for target '.tmp_versions/asix.mod'
scripts/Makefile.modpost:100: warning: ignoring old recipe for target '.tmp_versions/asix.mod'
scripts/Makefile.modpost:127: target '.tmp_versions/asix.mod' doesn't match the target pattern
scripts/Makefile.modpost:128: warning: overriding recipe for target '.tmp_versions/asix.mod'
scripts/Makefile.modpost:113: warning: ignoring old recipe for target '.tmp_versions/asix.mod'
make[2]: Circular .tmp_versions/asix.mod <- __modpost dependency dropped.
Binary file .tmp_versions/asix.mod matches: No such file or directory
make[2]: *** [scripts/Makefile.modpost:91: __modpost] Error 1
make[1]: *** [Makefile:1290: modules] Error 2

The only clue I can see is that asix.o gets built in two separate
directories (drivers/net/{phy,usb}).

I have the following files in the object directory:

./.tmp_versions/asix.mod
./drivers/net/usb/asix.ko
./drivers/net/usb/asix.mod.o
./drivers/net/usb/asix.o
./drivers/net/usb/asix_common.o
./drivers/net/usb/asix_devices.o
./drivers/net/usb/.asix.ko.cmd
./drivers/net/usb/.asix.mod.o.cmd
./drivers/net/usb/.asix.o.cmd
./drivers/net/usb/asix.mod.c
./drivers/net/usb/.asix_common.o.cmd
./drivers/net/usb/.asix_devices.o.cmd
./drivers/net/phy/asix.ko
./drivers/net/phy/asix.o
./drivers/net/phy/.asix.ko.cmd
./drivers/net/phy/.asix.mod.o.cmd
./drivers/net/phy/asix.mod.o
./drivers/net/phy/asix.mod.c
./drivers/net/phy/.asix.o.cmd

./.tmp_versions/asix.mod

Looks like this:

------------------------------------------
drivers/net/phy/asix.ko
drivers/net/phy/asix.o

------------------------------------------

What you can't see above are the 256 NUL bytes at the end of the file
(followed by a NL).

This is from a -j 80 build.  Surely there is a race condition here if the
file in .tmp_versions is only named for the base name of the module and
we have 2 modules with the same base name.

I removed that file and redid the build and it succeeded.

Mind you, I have no itdea why this file was begin rebuilt, the merge
only touched these files:

fs/ecryptfs/crypto.c
fs/ecryptfs/keystore.c

Puzzled ... :-(

-- 
Cheers,
Stephen Rothwell