2022-12-27 22:31:37

by Samuel Holland

Subject: [PATCH] kbuild: Fix running modpost with musl libc

commit 3d57e1b7b1d4 ("kbuild: refactor the prerequisites of the modpost
rule") moved 'vmlinux.o' inside modpost-args, possibly before some of
the other options. However, getopt() in musl libc follows POSIX and
stops looking for options upon reaching the first non-option argument.
As a result, the '-T' option is misinterpreted as a positional argument,
and the build fails:

make -f ./scripts/Makefile.modpost
scripts/mod/modpost -E -o Module.symvers vmlinux.o -T modules.order
-T: No such file or directory
make[1]: *** [scripts/Makefile.modpost:137: Module.symvers] Error 1
make: *** [Makefile:1960: modpost] Error 2

The fix is to move all options before 'vmlinux.o' in modpost-args.

Fixes: 3d57e1b7b1d4 ("kbuild: refactor the prerequisites of the modpost rule")
Signed-off-by: Samuel Holland <[email protected]>
---

scripts/Makefile.modpost | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index 5eb5e8280379..0ee296cf520c 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -55,6 +55,17 @@ ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
modpost-args += -n
endif

+ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
+modpost-args += -w
+endif
+
+# Read out modules.order to pass in modpost.
+# Otherwise, allmodconfig would fail with "Argument list too long".
+ifdef KBUILD_MODULES
+modpost-args += -T $(MODORDER)
+modpost-deps += $(MODORDER)
+endif
+
ifeq ($(KBUILD_EXTMOD),)

# Generate the list of in-tree objects in vmlinux
@@ -113,17 +124,6 @@ modpost-args += -e $(addprefix -i , $(KBUILD_EXTRA_SYMBOLS))

endif # ($(KBUILD_EXTMOD),)

-ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
-modpost-args += -w
-endif
-
-ifdef KBUILD_MODULES
-modpost-args += -T $(MODORDER)
-modpost-deps += $(MODORDER)
-endif
-
-# Read out modules.order to pass in modpost.
-# Otherwise, allmodconfig would fail with "Argument list too long".
quiet_cmd_modpost = MODPOST $@
cmd_modpost = \
$(if $(missing-input), \
--
2.37.4

2022-12-28 17:13:52

by Nathan Chancellor

Subject: Re: [PATCH] kbuild: Fix running modpost with musl libc

On Tue, Dec 27, 2022 at 03:48:21PM -0600, Samuel Holland wrote:
> commit 3d57e1b7b1d4 ("kbuild: refactor the prerequisites of the modpost
> rule") moved 'vmlinux.o' inside modpost-args, possibly before some of
> the other options. However, getopt() in musl libc follows POSIX and
> stops looking for options upon reaching the first non-option argument.
> As a result, the '-T' option is misinterpreted as a positional argument,
> and the build fails:
>
> make -f ./scripts/Makefile.modpost
> scripts/mod/modpost -E -o Module.symvers vmlinux.o -T modules.order
> -T: No such file or directory
> make[1]: *** [scripts/Makefile.modpost:137: Module.symvers] Error 1
> make: *** [Makefile:1960: modpost] Error 2
>
> The fix is to move all options before 'vmlinux.o' in modpost-args.
>
> Fixes: 3d57e1b7b1d4 ("kbuild: refactor the prerequisites of the modpost rule")
> Signed-off-by: Samuel Holland <[email protected]>

Seems reasonable to me.

Reviewed-by: Nathan Chancellor <[email protected]>

> ---
>
> scripts/Makefile.modpost | 22 +++++++++++-----------
> 1 file changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
> index 5eb5e8280379..0ee296cf520c 100644
> --- a/scripts/Makefile.modpost
> +++ b/scripts/Makefile.modpost
> @@ -55,6 +55,17 @@ ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
> modpost-args += -n
> endif
>
> +ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
> +modpost-args += -w
> +endif
> +
> +# Read out modules.order to pass in modpost.
> +# Otherwise, allmodconfig would fail with "Argument list too long".
> +ifdef KBUILD_MODULES
> +modpost-args += -T $(MODORDER)
> +modpost-deps += $(MODORDER)
> +endif
> +
> ifeq ($(KBUILD_EXTMOD),)
>
> # Generate the list of in-tree objects in vmlinux
> @@ -113,17 +124,6 @@ modpost-args += -e $(addprefix -i , $(KBUILD_EXTRA_SYMBOLS))
>
> endif # ($(KBUILD_EXTMOD),)
>
> -ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
> -modpost-args += -w
> -endif
> -
> -ifdef KBUILD_MODULES
> -modpost-args += -T $(MODORDER)
> -modpost-deps += $(MODORDER)
> -endif
> -
> -# Read out modules.order to pass in modpost.
> -# Otherwise, allmodconfig would fail with "Argument list too long".
> quiet_cmd_modpost = MODPOST $@
> cmd_modpost = \
> $(if $(missing-input), \
> --
> 2.37.4
>

2022-12-29 02:20:11

by Masahiro Yamada

Subject: Re: [PATCH] kbuild: Fix running modpost with musl libc

On Wed, Dec 28, 2022 at 6:48 AM Samuel Holland <[email protected]> wrote:
>
> commit 3d57e1b7b1d4 ("kbuild: refactor the prerequisites of the modpost
> rule") moved 'vmlinux.o' inside modpost-args, possibly before some of
> the other options. However, getopt() in musl libc follows POSIX and
> stops looking for options upon reaching the first non-option argument.
> As a result, the '-T' option is misinterpreted as a positional argument,
> and the build fails:
>
> make -f ./scripts/Makefile.modpost
> scripts/mod/modpost -E -o Module.symvers vmlinux.o -T modules.order
> -T: No such file or directory
> make[1]: *** [scripts/Makefile.modpost:137: Module.symvers] Error 1
> make: *** [Makefile:1960: modpost] Error 2
>
> The fix is to move all options before 'vmlinux.o' in modpost-args.
>
> Fixes: 3d57e1b7b1d4 ("kbuild: refactor the prerequisites of the modpost rule")
> Signed-off-by: Samuel Holland <[email protected]>
> ---
>



Applied to linux-kbuild/fixes. Thanks.


> scripts/Makefile.modpost | 22 +++++++++++-----------
> 1 file changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
> index 5eb5e8280379..0ee296cf520c 100644
> --- a/scripts/Makefile.modpost
> +++ b/scripts/Makefile.modpost
> @@ -55,6 +55,17 @@ ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),)
> modpost-args += -n
> endif
>
> +ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
> +modpost-args += -w
> +endif
> +
> +# Read out modules.order to pass in modpost.
> +# Otherwise, allmodconfig would fail with "Argument list too long".
> +ifdef KBUILD_MODULES
> +modpost-args += -T $(MODORDER)
> +modpost-deps += $(MODORDER)
> +endif
> +
> ifeq ($(KBUILD_EXTMOD),)
>
> # Generate the list of in-tree objects in vmlinux
> @@ -113,17 +124,6 @@ modpost-args += -e $(addprefix -i , $(KBUILD_EXTRA_SYMBOLS))
>
> endif # ($(KBUILD_EXTMOD),)
>
> -ifneq ($(KBUILD_MODPOST_WARN)$(missing-input),)
> -modpost-args += -w
> -endif
> -
> -ifdef KBUILD_MODULES
> -modpost-args += -T $(MODORDER)
> -modpost-deps += $(MODORDER)
> -endif
> -
> -# Read out modules.order to pass in modpost.
> -# Otherwise, allmodconfig would fail with "Argument list too long".
> quiet_cmd_modpost = MODPOST $@
> cmd_modpost = \
> $(if $(missing-input), \
> --
> 2.37.4
>


--
Best Regards
Masahiro Yamada

2023-01-04 08:46:14

by Christopher Schramm

Subject: Re: [PATCH] kbuild: Fix running modpost with musl libc

This change seems to break expected symbol warnings when building an
external module against a kernel prepared with modules_prepare.

The build used to show

WARNING: Module.symvers is missing.
Modules may not have dependencies or modversions.
You may get many unresolved symbol warnings.

followed by those many unresolved symbol warnings.

6.2-rc2 still shows that warning but the unresolved symbol messages are
now errors and the build fails (at scripts/Makefile.modpost:137). This
seems to happen due to -T getting added.