On Wed, May 15, 2019 at 9:39 AM Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> wrote: > > In the recent build test of linux-next, Stephen saw a build error > caused by a broken .tmp_versions/*.mod file: > > https://lkml.org/lkml/2019/5/13/991 > > drivers/net/phy/asix.ko and drivers/net/usb/asix.ko have the same > basename, and there is a race in generating .tmp_versions/asix.mod > > Kbuild has not checked this before, and it occasionally shows up with > obscure error message when this kind of race occurs. > > It is not trivial to catch this potential issue by eyes. > > Hence, this script. > > I compile-tested allmodconfig for the latest kernel as of writing, > it detected the following: > > warning: same basename '88pm800.ko' if the following are built as modules: > drivers/regulator/88pm800.ko > drivers/mfd/88pm800.ko > warning: same basename 'adv7511.ko' if the following are built as modules: > drivers/gpu/drm/bridge/adv7511/adv7511.ko > drivers/media/i2c/adv7511.ko > warning: same basename 'asix.ko' if the following are built as modules: > drivers/net/phy/asix.ko > drivers/net/usb/asix.ko > warning: same basename 'coda.ko' if the following are built as modules: > fs/coda/coda.ko > drivers/media/platform/coda/coda.ko > warning: same basename 'realtek.ko' if the following are built as modules: > drivers/net/phy/realtek.ko > drivers/net/dsa/realtek.ko > > Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> > Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> That looks great! > --- > > [Alternative fix ? ] > > I do not know about the user experience of modprobe etc. > when two different modules have the same name. > It does not matter if this is correctly handled by modules.order? > > If this is just a problem of the build system, it is pretty easy to fix. > For example, if we prepend the directory path, parallel build will > never write to the same file simultanously. > > asix.mod -> drivers/net/phy/asix.mod > asix.mod -> drivers/net/usb/asix.mod non-unique module names cause all kinds of problems, and modprobe can certainly not handle them correctly, and there are issues with symbols exported from a module when another one has the same name. Arnd
