[PATCH bpf-next 1/2] selftests/bpf: remove test_skb_cgroup_id.sh from TEST_PROGS

[PATCH bpf-next 1/2] selftests/bpf: remove test_skb_cgroup_id.sh from TEST_PROGS

[Ihor Solodrai]

test_skb_cgroup_id.sh was deleted in
https://git.kernel.org/bpf/bpf-next/c/f957c230e173

It has to be removed from TEST_PROGS variable in
tools/testing/selftests/bpf/Makefile, otherwise install target fails.

Link:
https://lore.kernel.org/bpf/Q3BN2kW9Kgy6LkrDOwnyY4Pv7_YF8fInLCd2_QA3LimKYM3wD64kRdnwp7blwG2dI_s7UGnfUae-4_dOmuTrxpYCi32G_KTzB3PfmxIerH8=@pm.me/

Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me>
---
 tools/testing/selftests/bpf/Makefile | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index f04af11df8eb..df75f1beb731 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -132,7 +132,6 @@ TEST_PROGS := test_kmod.sh \
 	test_tunnel.sh \
 	test_lwt_seg6local.sh \
 	test_lirc_mode2.sh \
-	test_skb_cgroup_id.sh \
 	test_flow_dissector.sh \
 	test_xdp_vlan_mode_generic.sh \
 	test_xdp_vlan_mode_native.sh \
-- 
2.34.1

[PATCH bpf-next 2/2] selftests/bpf: set vpath in Makefile to search for skels

[Ihor Solodrai]

Auto-dependencies generated for %.test.o files refer to skels using
filenames as opposed to full paths. This requires make to be able to
link this name to an actual path, because not all generated skels are
put in the working directory.

In the original patch [1], this was mitigated by this target:

$(notdir %.skel.h): $(TRUNNER_OUTPUT)/%.skel.h
	@true

This turned out to be insufficient.

First, %.lskel.h and %.subskel.h were missed, because a typical
selftests/bpf build could find these files in the working directory.
This error was detected by an out-of-tree build [2].

Second, even with missing rules added, this target causes unnecessary
rebuilds in the out-of-tree case, as X.skel.h is searched for in the
working directory, and not in the $(OUTPUT).

Using vpath directive [3] is a better solution. Instead of introducing
a separate target (X.skel.h in addition to $(TRUNNER_OUTPUT)/X.skel.h),
make is instructed to search for skels in the output, which allows make
to correctly detect that skel has already been generated.

[1]: https://lore.kernel.org/bpf/VJihUTnvtwEgv_mOnpfy7EgD9D2MPNoHO-MlANeLIzLJPGhDeyOuGKIYyKgk0O6KPjfM-MuhtvPwZcngN8WFqbTnTRyCSMc2aMZ1ODm1T_g=@pm.me/
[2]: https://lore.kernel.org/bpf/CIjrhJwoIqMc2IhuppVqh4ZtJGbx8kC8rc9PHhAIU6RccnWT4I04F_EIr4GxQwxZe89McuGJlCnUk9UbkdvWtSJjAsd7mHmnTy9F8K2TLZM=@pm.me/
[3]: https://www.gnu.org/software/make/manual/html_node/Selective-Search.html

Reported-by: Björn Töpel <bjorn@kernel.org>
Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me>
---
 tools/testing/selftests/bpf/Makefile | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index df75f1beb731..365740f24d2e 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -622,10 +622,11 @@ $(TRUNNER_BPF_SKELS_LINKED): $(TRUNNER_OUTPUT)/%: $$$$(%-deps) $(BPFTOOL) | $(TR
 
 # When the compiler generates a %.d file, only skel basenames (not
 # full paths) are specified as prerequisites for corresponding %.o
-# file. This target makes %.skel.h basename dependent on full paths,
-# linking generated %.d dependency with actual %.skel.h files.
-$(notdir %.skel.h): $(TRUNNER_OUTPUT)/%.skel.h
-	@true
+# file. vpath directives below instruct make to search for skel files
+# in TRUNNER_OUTPUT, if they are not present in the working directory.
+vpath %.skel.h $(TRUNNER_OUTPUT)
+vpath %.lskel.h $(TRUNNER_OUTPUT)
+vpath %.subskel.h $(TRUNNER_OUTPUT)
 
 endif
 
-- 
2.34.1

Re: [PATCH bpf-next 2/2] selftests/bpf: set vpath in Makefile to search for skels

[Ihor Solodrai]

On Monday, September 16th, 2024 at 12:59 PM, Ihor Solodrai <ihor.solodrai@pm.me> wrote:

[...]

> ---
> tools/testing/selftests/bpf/Makefile | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index df75f1beb731..365740f24d2e 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -622,10 +622,11 @@ $(TRUNNER_BPF_SKELS_LINKED): $(TRUNNER_OUTPUT)/%: $$$$(%-deps) $(BPFTOOL) | $(TR
> 
> # When the compiler generates a %.d file, only skel basenames (not
> # full paths) are specified as prerequisites for corresponding %.o
> -# file. This target makes %.skel.h basename dependent on full paths,
> -# linking generated %.d dependency with actual %.skel.h files.
> -$(notdir %.skel.h): $(TRUNNER_OUTPUT)/%.skel.h
> - @true
> +# file. vpath directives below instruct make to search for skel files
> +# in TRUNNER_OUTPUT, if they are not present in the working directory.
> +vpath %.skel.h $(TRUNNER_OUTPUT)
> +vpath %.lskel.h $(TRUNNER_OUTPUT)
> +vpath %.subskel.h $(TRUNNER_OUTPUT)
> 
> endif
> 
> --
> 2.34.1

Hi Björn.

It'd be great if you could confirm that this patch works for your
use-case.

Regarding unnecessary rebuilds, you will still see some skels and
bpf.o objects rebuilt on out-of-tree builds. These are related to
$(LINKED_SKELS) in selftests/bpf/Makefile. They are entangled with
%-deps variables, and I couldn't come up with a similar solution for
them quickly. However, there are just a couple of them, and the
rebuild is relatively fast, so I decided to submit a patch that fixes
most of the problem.

Thank you!

Re: [PATCH bpf-next 2/2] selftests/bpf: set vpath in Makefile to search for skels

[Eduard Zingerman]

On Mon, 2024-09-16 at 19:59 +0000, Ihor Solodrai wrote:

[...]

> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index df75f1beb731..365740f24d2e 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -622,10 +622,11 @@ $(TRUNNER_BPF_SKELS_LINKED): $(TRUNNER_OUTPUT)/%: $$$$(%-deps) $(BPFTOOL) | $(TR
>  
>  # When the compiler generates a %.d file, only skel basenames (not
>  # full paths) are specified as prerequisites for corresponding %.o
> -# file. This target makes %.skel.h basename dependent on full paths,
> -# linking generated %.d dependency with actual %.skel.h files.
> -$(notdir %.skel.h): $(TRUNNER_OUTPUT)/%.skel.h
> -	@true
> +# file. vpath directives below instruct make to search for skel files
> +# in TRUNNER_OUTPUT, if they are not present in the working directory.
> +vpath %.skel.h $(TRUNNER_OUTPUT)
> +vpath %.lskel.h $(TRUNNER_OUTPUT)
> +vpath %.subskel.h $(TRUNNER_OUTPUT)
>  
>  endif

When I try this patch, the following happens after first full tests build:

$ touch progs/verifier_and.c; make -j test_progs

  CLNG-BPF [test_progs] verifier_and.bpf.o
  CLNG-BPF [test_progs-no_alu32] verifier_and.bpf.o
  CLNG-BPF [test_progs-cpuv4] verifier_and.bpf.o
  GEN-SKEL [test_progs] verifier_and.skel.h
  GEN-SKEL [test_progs-no_alu32] verifier_and.skel.h
  GEN-SKEL [test_progs-cpuv4] verifier_and.skel.h
  TEST-OBJ [test_progs] verifier.test.o
  BINARY   test_progs

Note that multiple binaries are built.

Re: [PATCH bpf-next 1/2] selftests/bpf: remove test_skb_cgroup_id.sh from TEST_PROGS

[Björn Töpel]

Ihor Solodrai <ihor.solodrai@pm.me> writes:

> test_skb_cgroup_id.sh was deleted in
> https://git.kernel.org/bpf/bpf-next/c/f957c230e173
>
> It has to be removed from TEST_PROGS variable in
> tools/testing/selftests/bpf/Makefile, otherwise install target fails.
>
> Link:
> https://lore.kernel.org/bpf/Q3BN2kW9Kgy6LkrDOwnyY4Pv7_YF8fInLCd2_QA3LimKYM3wD64kRdnwp7blwG2dI_s7UGnfUae-4_dOmuTrxpYCi32G_KTzB3PfmxIerH8=@pm.me/
>
> Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me>

Tested-by: Björn Töpel <bjorn@rivosinc.com>

Re: [PATCH bpf-next 2/2] selftests/bpf: set vpath in Makefile to search for skels

[Björn Töpel]

Ihor Solodrai <ihor.solodrai@pm.me> writes:

> Auto-dependencies generated for %.test.o files refer to skels using
> filenames as opposed to full paths. This requires make to be able to
> link this name to an actual path, because not all generated skels are
> put in the working directory.
>
> In the original patch [1], this was mitigated by this target:
>
> $(notdir %.skel.h): $(TRUNNER_OUTPUT)/%.skel.h
> 	@true
>
> This turned out to be insufficient.
>
> First, %.lskel.h and %.subskel.h were missed, because a typical
> selftests/bpf build could find these files in the working directory.
> This error was detected by an out-of-tree build [2].
>
> Second, even with missing rules added, this target causes unnecessary
> rebuilds in the out-of-tree case, as X.skel.h is searched for in the
> working directory, and not in the $(OUTPUT).
>
> Using vpath directive [3] is a better solution. Instead of introducing
> a separate target (X.skel.h in addition to $(TRUNNER_OUTPUT)/X.skel.h),
> make is instructed to search for skels in the output, which allows make
> to correctly detect that skel has already been generated.
>
> [1]: https://lore.kernel.org/bpf/VJihUTnvtwEgv_mOnpfy7EgD9D2MPNoHO-MlANeLIzLJPGhDeyOuGKIYyKgk0O6KPjfM-MuhtvPwZcngN8WFqbTnTRyCSMc2aMZ1ODm1T_g=@pm.me/
> [2]: https://lore.kernel.org/bpf/CIjrhJwoIqMc2IhuppVqh4ZtJGbx8kC8rc9PHhAIU6RccnWT4I04F_EIr4GxQwxZe89McuGJlCnUk9UbkdvWtSJjAsd7mHmnTy9F8K2TLZM=@pm.me/
> [3]: https://www.gnu.org/software/make/manual/html_node/Selective-Search.html
>
> Reported-by: Björn Töpel <bjorn@kernel.org>
> Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me>

As you point out, there are rebuilds triggered for the bpf "install"
target. Now rebuild are better than failures. Thanks for the fix!

Tested-by: Björn Töpel <bjorn@rivosinc.com>

Re: [PATCH bpf-next 2/2] selftests/bpf: set vpath in Makefile to search for skels

[Ihor Solodrai]

On Monday, September 16th, 2024 at 9:00 PM, Eduard Zingerman <eddyz87@gmail.com> wrote:

[...]

> 
> When I try this patch, the following happens after first full tests build:
> 
> $ touch progs/verifier_and.c; make -j test_progs
> 
> CLNG-BPF [test_progs] verifier_and.bpf.o
> CLNG-BPF [test_progs-no_alu32] verifier_and.bpf.o
> CLNG-BPF [test_progs-cpuv4] verifier_and.bpf.o
> GEN-SKEL [test_progs] verifier_and.skel.h
> GEN-SKEL [test_progs-no_alu32] verifier_and.skel.h
> GEN-SKEL [test_progs-cpuv4] verifier_and.skel.h
> TEST-OBJ [test_progs] verifier.test.o
> BINARY test_progs
> 
> Note that multiple binaries are built.

Eduard, I've just tried on master (without this patch)

    $ touch progs/verifier_and.c; make -j test_progs

and I get a similar sequence:

    CLNG-BPF [test_progs] verifier_and.bpf.o
    GEN-SKEL [test_progs] verifier_and.skel.h
    CLNG-BPF [test_progs-cpuv4] verifier_and.bpf.o
    GEN-SKEL [test_progs-cpuv4] verifier_and.skel.h
    CLNG-BPF [test_progs-no_alu32] verifier_and.bpf.o
    GEN-SKEL [test_progs-no_alu32] verifier_and.skel.h
    TEST-OBJ [test_progs] verifier.test.o
    BINARY   test_progs
    TEST-OBJ [test_progs-no_alu32] verifier.test.o
    EXT-COPY [test_progs-no_alu32] urandom_read bpf_testmod.ko bpf_test_no_cfi.ko liburandom_read.so xdp_synproxy sign-file uprobe_multi ima_setup.sh verify_sig_setup.sh btf_dump_test_case_bitfields.c btf_dump_test_case_multidim.c btf_dump_test_case_namespacing.c btf_dump_test_case_ordering.c btf_dump_test_case_packing.c btf_dump_test_case_padding.c btf_dump_test_case_syntax.c
    BINARY   test_progs-no_alu32
    TEST-OBJ [test_progs-cpuv4] verifier.test.o
    EXT-COPY [test_progs-cpuv4] urandom_read bpf_testmod.ko bpf_test_no_cfi.ko liburandom_read.so xdp_synproxy sign-file uprobe_multi ima_setup.sh verify_sig_setup.sh btf_dump_test_case_bitfields.c btf_dump_test_case_multidim.c btf_dump_test_case_namespacing.c btf_dump_test_case_ordering.c btf_dump_test_case_packing.c btf_dump_test_case_padding.c btf_dump_test_case_syntax.c
    BINARY   test_progs-cpuv4


%.bpf.o -> %.skel.h -> %.test.o have to be built for each TRUNNER,
right? And then each TRUNNER needs to be rebuilt because of %.test.o
change. Using vpath for skels doesn't change this behavior.

Maybe I'm missing something, let me know.

Re: [PATCH bpf-next 2/2] selftests/bpf: set vpath in Makefile to search for skels

[Eduard Zingerman]

On Tue, 2024-09-17 at 15:04 +0000, Ihor Solodrai wrote:

[...]

> Eduard, I've just tried on master (without this patch)
> 
>     $ touch progs/verifier_and.c; make -j test_progs
> 
> and I get a similar sequence:
> 
>     CLNG-BPF [test_progs] verifier_and.bpf.o
>     GEN-SKEL [test_progs] verifier_and.skel.h
>     CLNG-BPF [test_progs-cpuv4] verifier_and.bpf.o
>     GEN-SKEL [test_progs-cpuv4] verifier_and.skel.h
>     CLNG-BPF [test_progs-no_alu32] verifier_and.bpf.o
>     GEN-SKEL [test_progs-no_alu32] verifier_and.skel.h
>     TEST-OBJ [test_progs] verifier.test.o
>     BINARY   test_progs
>     TEST-OBJ [test_progs-no_alu32] verifier.test.o
>     EXT-COPY [test_progs-no_alu32] urandom_read bpf_testmod.ko bpf_test_no_cfi.ko liburandom_read.so xdp_synproxy sign-file uprobe_multi ima_setup.sh verify_sig_setup.sh btf_dump_test_case_bitfields.c btf_dump_test_case_multidim.c btf_dump_test_case_namespacing.c btf_dump_test_case_ordering.c btf_dump_test_case_packing.c btf_dump_test_case_padding.c btf_dump_test_case_syntax.c
>     BINARY   test_progs-no_alu32
>     TEST-OBJ [test_progs-cpuv4] verifier.test.o
>     EXT-COPY [test_progs-cpuv4] urandom_read bpf_testmod.ko bpf_test_no_cfi.ko liburandom_read.so xdp_synproxy sign-file uprobe_multi ima_setup.sh verify_sig_setup.sh btf_dump_test_case_bitfields.c btf_dump_test_case_multidim.c btf_dump_test_case_namespacing.c btf_dump_test_case_ordering.c btf_dump_test_case_packing.c btf_dump_test_case_padding.c btf_dump_test_case_syntax.c
>     BINARY   test_progs-cpuv4
> 
> 
> %.bpf.o -> %.skel.h -> %.test.o have to be built for each TRUNNER,
> right? And then each TRUNNER needs to be rebuilt because of %.test.o
> change. Using vpath for skels doesn't change this behavior.
> 
> Maybe I'm missing something, let me know.
> 

Hm, right, sorry for the noise.

Re: [PATCH bpf-next 1/2] selftests/bpf: remove test_skb_cgroup_id.sh from TEST_PROGS

[patchwork-bot+netdevbpf]

Hello:

This series was applied to bpf/bpf-next.git (master)
by Andrii Nakryiko <andrii@kernel.org>:

On Mon, 16 Sep 2024 19:59:22 +0000 you wrote:
> test_skb_cgroup_id.sh was deleted in
> https://git.kernel.org/bpf/bpf-next/c/f957c230e173
> 
> It has to be removed from TEST_PROGS variable in
> tools/testing/selftests/bpf/Makefile, otherwise install target fails.
> 
> Link:
> https://lore.kernel.org/bpf/Q3BN2kW9Kgy6LkrDOwnyY4Pv7_YF8fInLCd2_QA3LimKYM3wD64kRdnwp7blwG2dI_s7UGnfUae-4_dOmuTrxpYCi32G_KTzB3PfmxIerH8=@pm.me/
> 
> [...]

Here is the summary with links:
  - [bpf-next,1/2] selftests/bpf: remove test_skb_cgroup_id.sh from TEST_PROGS
    https://git.kernel.org/bpf/bpf-next/c/e4c139a63aff
  - [bpf-next,2/2] selftests/bpf: set vpath in Makefile to search for skels
    https://git.kernel.org/bpf/bpf-next/c/494c3a797257

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: [PATCH bpf-next 1/2] selftests/bpf: remove test_skb_cgroup_id.sh from TEST_PROGS

[Matthieu Baerts]

Hi Andrii,

(+cc Geliang who reported me the issue)

On 24/09/2024 08:20, patchwork-bot+netdevbpf@kernel.org wrote:
> Hello:
> 
> This series was applied to bpf/bpf-next.git (master)
> by Andrii Nakryiko <andrii@kernel.org>:
> 
> On Mon, 16 Sep 2024 19:59:22 +0000 you wrote:
>> test_skb_cgroup_id.sh was deleted in
>> https://git.kernel.org/bpf/bpf-next/c/f957c230e173
>>
>> It has to be removed from TEST_PROGS variable in
>> tools/testing/selftests/bpf/Makefile, otherwise install target fails.
>>
>> Link:
>> https://lore.kernel.org/bpf/Q3BN2kW9Kgy6LkrDOwnyY4Pv7_YF8fInLCd2_QA3LimKYM3wD64kRdnwp7blwG2dI_s7UGnfUae-4_dOmuTrxpYCi32G_KTzB3PfmxIerH8=@pm.me/

It looks like the two patches here are fixing issues that are on v6.12
as well: I'm on top of net-next, and I can see these issues. They are
fixed by these two patches that can be applied without conflicts.

In these patches, we can find references to the commits that introduced
the issues:

- Patch 1: f957c230e173 ("selftests/bpf: convert test_skb_cgroup_id_user
to test_progs")

- Patch 2: 844f7315e77a ("selftests/bpf: Use auto-dependencies for test
objects")

The two commits are in v6.12-rc1. Could it eventually be possible to
apply these two patches (with Fixes tags?) in the 'bpf' tree instead of
the 'bpf-next' one please?

> Here is the summary with links:
>   - [bpf-next,1/2] selftests/bpf: remove test_skb_cgroup_id.sh from TEST_PROGS
>     https://git.kernel.org/bpf/bpf-next/c/e4c139a63aff

Just in case, it looks like the history has been rewritten. The last ref
seems to be:

  d002b922c4d5 ("selftests/bpf: Remove test_skb_cgroup_id.sh from
TEST_PROGS")

>   - [bpf-next,2/2] selftests/bpf: set vpath in Makefile to search for skels
>     https://git.kernel.org/bpf/bpf-next/c/494c3a797257

... and:

  fd4a0e67838c ("selftests/bpf: Set vpath in Makefile to search for skels")

Thank you!

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.

Re: [PATCH bpf-next 1/2] selftests/bpf: remove test_skb_cgroup_id.sh from TEST_PROGS

[Andrii Nakryiko]

On Mon, Nov 4, 2024 at 8:31 AM Matthieu Baerts <matttbe@kernel.org> wrote:
>
> Hi Andrii,
>
> (+cc Geliang who reported me the issue)
>
> On 24/09/2024 08:20, patchwork-bot+netdevbpf@kernel.org wrote:
> > Hello:
> >
> > This series was applied to bpf/bpf-next.git (master)
> > by Andrii Nakryiko <andrii@kernel.org>:
> >
> > On Mon, 16 Sep 2024 19:59:22 +0000 you wrote:
> >> test_skb_cgroup_id.sh was deleted in
> >> https://git.kernel.org/bpf/bpf-next/c/f957c230e173
> >>
> >> It has to be removed from TEST_PROGS variable in
> >> tools/testing/selftests/bpf/Makefile, otherwise install target fails.
> >>
> >> Link:
> >> https://lore.kernel.org/bpf/Q3BN2kW9Kgy6LkrDOwnyY4Pv7_YF8fInLCd2_QA3LimKYM3wD64kRdnwp7blwG2dI_s7UGnfUae-4_dOmuTrxpYCi32G_KTzB3PfmxIerH8=@pm.me/
>
> It looks like the two patches here are fixing issues that are on v6.12
> as well: I'm on top of net-next, and I can see these issues. They are
> fixed by these two patches that can be applied without conflicts.
>
> In these patches, we can find references to the commits that introduced
> the issues:
>
> - Patch 1: f957c230e173 ("selftests/bpf: convert test_skb_cgroup_id_user
> to test_progs")
>
> - Patch 2: 844f7315e77a ("selftests/bpf: Use auto-dependencies for test
> objects")
>
> The two commits are in v6.12-rc1. Could it eventually be possible to
> apply these two patches (with Fixes tags?) in the 'bpf' tree instead of
> the 'bpf-next' one please?

Those patches landed back in September, more than a month ago, so it's
way too late to move them between the trees, unfortunately. You'll
probably have to do a stable backport, I'm sorry.

>
> > Here is the summary with links:
> >   - [bpf-next,1/2] selftests/bpf: remove test_skb_cgroup_id.sh from TEST_PROGS
> >     https://git.kernel.org/bpf/bpf-next/c/e4c139a63aff
>
> Just in case, it looks like the history has been rewritten. The last ref
> seems to be:
>
>   d002b922c4d5 ("selftests/bpf: Remove test_skb_cgroup_id.sh from
> TEST_PROGS")
>
> >   - [bpf-next,2/2] selftests/bpf: set vpath in Makefile to search for skels
> >     https://git.kernel.org/bpf/bpf-next/c/494c3a797257
>
> ... and:
>
>   fd4a0e67838c ("selftests/bpf: Set vpath in Makefile to search for skels")
>
> Thank you!
>
> Cheers,
> Matt
> --
> Sponsored by the NGI0 Core fund.
>