diff mbox series

[v3] kbuild: check uniqueness of module names

Message ID 1558109235-23042-1-git-send-email-yamada.masahiro@socionext.com
State Accepted
Commit 3a48a91901c516a46a3406ea576798538a8d94d2
Headers show
Series [v3] kbuild: check uniqueness of module names | expand

Commit Message

Masahiro Yamada May 17, 2019, 4:07 p.m. UTC
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 suddenly shows up with
obscure error message when this kind of race occurs.

Non-unique module names cause various sort of problems, but it is
not trivial to catch them by eyes.

Hence, this script.

It checks not only real modules, but also built-in modules (i.e.
controlled by tristate CONFIG option, but currently compiled with =y).
Non-unique names for built-in modules also cause problems because
/sys/modules/ would fall over.

I tested allmodconfig on the latest kernel, and it detected the
following:

warning: same basename if the following are built as modules:
  drivers/regulator/88pm800.ko
  drivers/mfd/88pm800.ko
warning: same basename if the following are built as modules:
  drivers/gpu/drm/bridge/adv7511/adv7511.ko
  drivers/media/i2c/adv7511.ko
warning: same basename if the following are built as modules:
  drivers/net/phy/asix.ko
  drivers/net/usb/asix.ko
warning: same basename if the following are built as modules:
  fs/coda/coda.ko
  drivers/media/platform/coda/coda.ko
warning: same basename if the following are built as modules:
  drivers/net/phy/realtek.ko
  drivers/net/dsa/realtek.ko

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>

Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>

---

Changes in v3:
 - Simplied sed code (Alexander Kapshuk)

Changes in v2:
 - redirect messages to stderr
 - use '--' after 'basename -a'
 - use '-r' for xargs to cope with empty modules.order/modules.builtin

 Makefile                 |  1 +
 scripts/modules-check.sh | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)
 create mode 100755 scripts/modules-check.sh

-- 
2.7.4

Comments

Masahiro Yamada May 17, 2019, 4:54 p.m. UTC | #1
On Sat, May 18, 2019 at 1:10 AM Masahiro Yamada
<yamada.masahiro@socionext.com> 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 suddenly shows up with

> obscure error message when this kind of race occurs.

>

> Non-unique module names cause various sort of problems, but it is

> not trivial to catch them by eyes.

>

> Hence, this script.

>

> It checks not only real modules, but also built-in modules (i.e.

> controlled by tristate CONFIG option, but currently compiled with =y).

> Non-unique names for built-in modules also cause problems because

> /sys/modules/ would fall over.

>

> I tested allmodconfig on the latest kernel, and it detected the

> following:



FYI.

"make -j8 allmodconfig all"
takes long time to compile
(my machine is cheap...)


If you want to detect modules with non-unique name quickly,
"make -j8 allyesconfig modules" is much faster.






> warning: same basename if the following are built as modules:

>   drivers/regulator/88pm800.ko

>   drivers/mfd/88pm800.ko

> warning: same basename if the following are built as modules:

>   drivers/gpu/drm/bridge/adv7511/adv7511.ko

>   drivers/media/i2c/adv7511.ko

> warning: same basename if the following are built as modules:

>   drivers/net/phy/asix.ko

>   drivers/net/usb/asix.ko

> warning: same basename if the following are built as modules:

>   fs/coda/coda.ko

>   drivers/media/platform/coda/coda.ko

> warning: same basename if the following are built as modules:

>   drivers/net/phy/realtek.ko

>   drivers/net/dsa/realtek.ko

>

> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>

> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

> Reviewed-by: Kees Cook <keescook@chromium.org>

> Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>

> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>

> ---

>

> Changes in v3:

>  - Simplied sed code (Alexander Kapshuk)

>

> Changes in v2:

>  - redirect messages to stderr

>  - use '--' after 'basename -a'

>  - use '-r' for xargs to cope with empty modules.order/modules.builtin

>

>  Makefile                 |  1 +

>  scripts/modules-check.sh | 16 ++++++++++++++++

>  2 files changed, 17 insertions(+)

>  create mode 100755 scripts/modules-check.sh

>

> diff --git a/Makefile b/Makefile

> index a61a95b..30792fe 100644

> --- a/Makefile

> +++ b/Makefile

> @@ -1290,6 +1290,7 @@ modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin

>         $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order

>         @$(kecho) '  Building modules, stage 2.';

>         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost

> +       $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh

>

>  modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)

>         $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin

> diff --git a/scripts/modules-check.sh b/scripts/modules-check.sh

> new file mode 100755

> index 0000000..2f65953

> --- /dev/null

> +++ b/scripts/modules-check.sh

> @@ -0,0 +1,16 @@

> +#!/bin/sh

> +# SPDX-License-Identifier: GPL-2.0

> +

> +set -e

> +

> +# Check uniqueness of module names

> +check_same_name_modules()

> +{

> +       for m in $(sed 's:.*/::' modules.order modules.builtin | sort | uniq -d)

> +       do

> +               echo "warning: same basename if the following are built as modules:" >&2

> +               sed "/\/$m/!d;s:^kernel/:  :" modules.order modules.builtin >&2

> +       done

> +}

> +

> +check_same_name_modules

> --

> 2.7.4

>



--
Best Regards
Masahiro Yamada
Greg Kroah-Hartman May 19, 2019, 7:16 a.m. UTC | #2
On Sat, May 18, 2019 at 01:07:15AM +0900, Masahiro Yamada 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 suddenly shows up with

> obscure error message when this kind of race occurs.

> 

> Non-unique module names cause various sort of problems, but it is

> not trivial to catch them by eyes.

> 

> Hence, this script.

> 

> It checks not only real modules, but also built-in modules (i.e.

> controlled by tristate CONFIG option, but currently compiled with =y).

> Non-unique names for built-in modules also cause problems because

> /sys/modules/ would fall over.

> 

> I tested allmodconfig on the latest kernel, and it detected the

> following:

> 

> warning: same basename if the following are built as modules:

>   drivers/regulator/88pm800.ko

>   drivers/mfd/88pm800.ko

> warning: same basename if the following are built as modules:

>   drivers/gpu/drm/bridge/adv7511/adv7511.ko

>   drivers/media/i2c/adv7511.ko

> warning: same basename if the following are built as modules:

>   drivers/net/phy/asix.ko

>   drivers/net/usb/asix.ko

> warning: same basename if the following are built as modules:

>   fs/coda/coda.ko

>   drivers/media/platform/coda/coda.ko

> warning: same basename if the following are built as modules:

>   drivers/net/phy/realtek.ko

>   drivers/net/dsa/realtek.ko

> 

> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>

> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

> Reviewed-by: Kees Cook <keescook@chromium.org>

> Reviewed-by: Stephen Rothwell <sfr@canb.auug.org.au>

> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>


Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stephen Rothwell May 19, 2019, 11:51 p.m. UTC | #3
Hi Masahiro,

On Sat, 18 May 2019 01:07:15 +0900 Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>

> It checks not only real modules, but also built-in modules (i.e.

> controlled by tristate CONFIG option, but currently compiled with =y).

> Non-unique names for built-in modules also cause problems because

> /sys/modules/ would fall over.

> 

> I tested allmodconfig on the latest kernel, and it detected the

> following:


A powerpc ppc64_defconfig produces:

warning: same basename if the following are built as modules:
  arch/powerpc/platforms/powermac/nvram.ko
  drivers/char/nvram.ko

Which is a false positive since
arch/powerpc/platforms/powermac/Makefile has

# CONFIG_NVRAM is an arch. independent tristate symbol, for pmac32 we really
# need this to be a bool.  Cheat here and pretend CONFIG_NVRAM=m is really
# CONFIG_NVRAM=y
obj-$(CONFIG_NVRAM:m=y)         += nvram.o

Which means that this nvram.o will never be built as a module.
-- 
Cheers,
Stephen Rothwell
Stephen Rothwell May 20, 2019, 12:04 a.m. UTC | #4
Hi Masahiro,

On Sat, 18 May 2019 01:07:15 +0900 Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
> 

> +++ b/scripts/modules-check.sh

> @@ -0,0 +1,16 @@

> +#!/bin/sh

> +# SPDX-License-Identifier: GPL-2.0

> +

> +set -e

> +

> +# Check uniqueness of module names

> +check_same_name_modules()

> +{

> +	for m in $(sed 's:.*/::' modules.order modules.builtin | sort | uniq -d)

> +	do

> +		echo "warning: same basename if the following are built as modules:" >&2

> +		sed "/\/$m/!d;s:^kernel/:  :" modules.order modules.builtin >&2


(bringing out my bike shed paint brush :-))
this could be
	sed -n "/\/$m/s:^kernel/:  :p" ...

-- 
Cheers,
Stephen Rothwell
Masahiro Yamada May 20, 2019, 2:13 a.m. UTC | #5
Hi Stephen,

On Mon, May 20, 2019 at 8:52 AM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>

> Hi Masahiro,

>

> On Sat, 18 May 2019 01:07:15 +0900 Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> >

> > It checks not only real modules, but also built-in modules (i.e.

> > controlled by tristate CONFIG option, but currently compiled with =y).

> > Non-unique names for built-in modules also cause problems because

> > /sys/modules/ would fall over.

> >

> > I tested allmodconfig on the latest kernel, and it detected the

> > following:

>

> A powerpc ppc64_defconfig produces:

>

> warning: same basename if the following are built as modules:

>   arch/powerpc/platforms/powermac/nvram.ko

>   drivers/char/nvram.ko

>

> Which is a false positive since

> arch/powerpc/platforms/powermac/Makefile has

>

> # CONFIG_NVRAM is an arch. independent tristate symbol, for pmac32 we really

> # need this to be a bool.  Cheat here and pretend CONFIG_NVRAM=m is really

> # CONFIG_NVRAM=y

> obj-$(CONFIG_NVRAM:m=y)         += nvram.o

>

> Which means that this nvram.o will never be built as a module.


Indeed.

I thought it was a good idea to check built-in modules,
but I do not have a good way to avoid false positives.

I think we should not check modules.builtin.
Anyway, allmodconfig has a good test coverage.

The following is the planned fix.
(I folded your sed code.)




diff --git a/scripts/modules-check.sh b/scripts/modules-check.sh
index 2f659530e1ec..39e8cb36ba19 100755
--- a/scripts/modules-check.sh
+++ b/scripts/modules-check.sh
@@ -6,10 +6,10 @@ set -e
 # Check uniqueness of module names
 check_same_name_modules()
 {
-       for m in $(sed 's:.*/::' modules.order modules.builtin | sort | uniq -d)
+       for m in $(sed 's:.*/::' modules.order | sort | uniq -d)
        do
-               echo "warning: same basename if the following are
built as modules:" >&2
-               sed "/\/$m/!d;s:^kernel/:  :" modules.order modules.builtin >&2
+               echo "warning: same module names found:" >&2
+               sed -n "/\/$m/s:^kernel/:  :p" modules.order >&2
        done
 }






> --

> Cheers,

> Stephen Rothwell




--
Best Regards
Masahiro Yamada
Masahiro Yamada May 20, 2019, 3:59 a.m. UTC | #6
On Mon, May 20, 2019 at 8:52 AM Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>

> Hi Masahiro,

>

> On Sat, 18 May 2019 01:07:15 +0900 Masahiro Yamada <yamada.masahiro@socionext.com> wrote:

> >

> > It checks not only real modules, but also built-in modules (i.e.

> > controlled by tristate CONFIG option, but currently compiled with =y).

> > Non-unique names for built-in modules also cause problems because

> > /sys/modules/ would fall over.

> >

> > I tested allmodconfig on the latest kernel, and it detected the

> > following:

>

> A powerpc ppc64_defconfig produces:

>

> warning: same basename if the following are built as modules:

>   arch/powerpc/platforms/powermac/nvram.ko

>   drivers/char/nvram.ko

>

> Which is a false positive since

> arch/powerpc/platforms/powermac/Makefile has

>

> # CONFIG_NVRAM is an arch. independent tristate symbol, for pmac32 we really

> # need this to be a bool.  Cheat here and pretend CONFIG_NVRAM=m is really

> # CONFIG_NVRAM=y

> obj-$(CONFIG_NVRAM:m=y)         += nvram.o

>

> Which means that this nvram.o will never be built as a module.

> --

> Cheers,

> Stephen Rothwell



BTW, arm64 defconfig also produces a false positive:

warning: same basename if the following are built as modules:
  arch/arm64/lib/crc32.ko
  lib/crc32.ko

CONFIG_CRC32 is a tristate option, but ARM64 selects CRC32.
So, CRC32 is always =y.


We must stop checking modules.builtin soon.
Sorry about noises.




-- 
Best Regards
Masahiro Yamada
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index a61a95b..30792fe 100644
--- a/Makefile
+++ b/Makefile
@@ -1290,6 +1290,7 @@  modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
 	$(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
 	@$(kecho) '  Building modules, stage 2.';
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
+	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh
 
 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
 	$(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
diff --git a/scripts/modules-check.sh b/scripts/modules-check.sh
new file mode 100755
index 0000000..2f65953
--- /dev/null
+++ b/scripts/modules-check.sh
@@ -0,0 +1,16 @@ 
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+
+# Check uniqueness of module names
+check_same_name_modules()
+{
+	for m in $(sed 's:.*/::' modules.order modules.builtin | sort | uniq -d)
+	do
+		echo "warning: same basename if the following are built as modules:" >&2
+		sed "/\/$m/!d;s:^kernel/:  :" modules.order modules.builtin >&2
+	done
+}
+
+check_same_name_modules