Re: [PATCH net-next v14 13/13] selftests: add ncdevmem, netcat for devmem TCP

Mina Almasry
2024-06-27T19:55:54Z

On Wed, Jun 26, 2024 at 5:46 PM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Wed, 26 Jun 2024 15:08:22 -0700 Jakub Kicinski wrote:
> > On Tue, 25 Jun 2024 19:54:01 +0000 Mina Almasry wrote:
> > > +CFLAGS += -I../../../net/ynl/generated/
> > > +CFLAGS += -I../../../net/ynl/lib/
> > > +
> > > +LDLIBS += ../../../net/ynl/lib/ynl.a ../../../net/ynl/generated/protos.a
> >
> > Not as easy as this.. Please add this commit to your series:
> > https://github.com/kuba-moo/linux/commit/c130e8cc7208be544ec4f6f3627f1d36875d8c47
> >
> > And here's an example of how you then use ynl.mk to code gen and build
> > for desired families (note the ordering of variables vs includes,
> > I remember that part was quite inflexible..):
> > https://github.com/kuba-moo/linux/commit/5d357f97ccd0248ca6136c5e11ca3eadf5091bb3
>
> Investigating this further my patches will not work for O=xyz builds
> either. Please squash this into the relevant changes:
>

Thanks! I cherry-picked commit 15dbefa97fb98 ("tools: net: package
libynl for use in selftests"), and then applied the diff below to the
series [1].

Now:

`git clean -fdx && make headers_install && make -C
./tools/testing/selftests/net` works

`git clean -fdx && make headers_install && make -C
./tools/testing/selftests/net ncdevmem` doesn't work with this error:

make: Entering directory
'/usr/local/google/home/almasrymina/cos-kernel/tools/testing/selftests/net'
gcc -Wall -Wl,--no-as-needed -O2 -g -I../../../../usr/include/
-isystem /usr/local/google/home/almasrymina/cos-kernel/tools/testing/selftests/../../../usr/include
-I../ ncdevmem.c -lmnl -o ncdevmem
ncdevmem.c:34:10: fatal error: netdev-user.h: No such file or directory
34 | #include "netdev-user.h"
| ^~~~~~~~~~~~~~~
compilation terminated.
make: *** [<builtin>: ncdevmem] Error 1

It seems specifying the target doesn't trigger the libynl.a to be
built. Isn't this a bug, or is that expected? I took a bit of a look
into it but couldn't figure it out immediately. If it is a bug, any
pointers would be appreciated (but I'm digging into it anyway).

[1] The diff on top of the series-with-cherry-pick that I'm testing with:

diff --git a/tools/testing/selftests/net/Makefile
b/tools/testing/selftests/net/Makefile
index 7ba1505dc2eb4..1d3b99e9c12e8 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -5,10 +5,6 @@ CFLAGS += -Wall -Wl,--no-as-needed -O2 -g
CFLAGS += -I../../../../usr/include/ $(KHDR_INCLUDES)
# Additional include paths needed by kselftest.h
CFLAGS += -I../
-CFLAGS += -I../../../net/ynl/generated/
-CFLAGS += -I../../../net/ynl/lib/
-
-LDLIBS += ../../../net/ynl/lib/ynl.a ../../../net/ynl/generated/protos.a

LDLIBS += -lmnl

@@ -100,7 +96,11 @@ TEST_PROGS += fdb_flush.sh
TEST_PROGS += fq_band_pktlimit.sh
TEST_PROGS += vlan_hw_filter.sh
TEST_PROGS += bpf_offload.py
-TEST_GEN_FILES += ncdevmem
+
+# YNL files, must be before "include ..lib.mk"
+EXTRA_CLEAN += $(OUTPUT)/libynl.a
+YNL_GEN_FILES := ncdevmem
+TEST_GEN_FILES += $(YNL_GEN_FILES)

TEST_FILES := settings
TEST_FILES += in_netns.sh lib.sh net_helper.sh setup_loopback.sh setup_veth.sh
@@ -111,6 +111,10 @@ TEST_INCLUDES := forwarding/lib.sh

include ../lib.mk

+# YNL build
+YNL_GENS := netdev
+include ynl.mk
+
$(OUTPUT)/epoll_busy_poll: LDLIBS += -lcap
$(OUTPUT)/reuseport_bpf_numa: LDLIBS += -lnuma
$(OUTPUT)/tcp_mmap: LDLIBS += -lpthread -lcrypto
diff --git a/tools/testing/selftests/net/ynl.mk
b/tools/testing/selftests/net/ynl.mk
index 0e01ad12b30ec..59cb26cf3f738 100644
--- a/tools/testing/selftests/net/ynl.mk
+++ b/tools/testing/selftests/net/ynl.mk
@@ -18,6 +18,4 @@ $(YNL_OUTPUTS): CFLAGS += \

$(OUTPUT)/libynl.a:
$(Q)$(MAKE) -C $(top_srcdir)/tools/net/ynl GENS="$(YNL_GENS)" libynl.a
- $(Q)cp $(top_srcdir)/tools/net/ynl/libynl.a ./
-
-EXTRA_CLEAN += libynl.a
+ $(Q)cp $(top_srcdir)/tools/net/ynl/libynl.a $(OUTPUT)/libynl.a

--
Thanks,
Mina