<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/samples/bpf/Makefile, branch linux-5.17.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>samples: bpf: Don't fail for a missing VMLINUX_BTF when VMLINUX_H is provided</title>
<updated>2022-06-09T08:25:48+00:00</updated>
<author>
<name>Jerome Marchand</name>
<email>jmarchan@redhat.com</email>
</author>
<published>2022-05-07T16:16:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=994eb459c71fef43d735ec08aafb2d04037aad57'/>
<id>994eb459c71fef43d735ec08aafb2d04037aad57</id>
<content type='text'>
[ Upstream commit ec24704492d8791a52a75a39e3ad762b6e017bc6 ]

samples/bpf build currently always fails if it can't generate
vmlinux.h from vmlinux, even when vmlinux.h is directly provided by
VMLINUX_H variable, which makes VMLINUX_H pointless.
Only fails when neither method works.

Fixes: 384b6b3bbf0d ("samples: bpf: Add vmlinux.h generation support")
Reported-by: CKI Project &lt;cki-project@redhat.com&gt;
Reported-by: Veronika Kabatova &lt;vkabatov@redhat.com&gt;
Signed-off-by: Jerome Marchand &lt;jmarchan@redhat.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20220507161635.2219052-1-jmarchan@redhat.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit ec24704492d8791a52a75a39e3ad762b6e017bc6 ]

samples/bpf build currently always fails if it can't generate
vmlinux.h from vmlinux, even when vmlinux.h is directly provided by
VMLINUX_H variable, which makes VMLINUX_H pointless.
Only fails when neither method works.

Fixes: 384b6b3bbf0d ("samples: bpf: Add vmlinux.h generation support")
Reported-by: CKI Project &lt;cki-project@redhat.com&gt;
Reported-by: Veronika Kabatova &lt;vkabatov@redhat.com&gt;
Signed-off-by: Jerome Marchand &lt;jmarchan@redhat.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20220507161635.2219052-1-jmarchan@redhat.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples: bpf: Fix xdp_sample_user.o linking with Clang</title>
<updated>2021-12-07T03:33:44+00:00</updated>
<author>
<name>Alexander Lobakin</name>
<email>alexandr.lobakin@intel.com</email>
</author>
<published>2021-12-03T19:50:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e64fbcaa7a666f16329b1c67af15ea501bc84586'/>
<id>e64fbcaa7a666f16329b1c67af15ea501bc84586</id>
<content type='text'>
Clang (13) doesn't get the jokes about specifying libraries to link in
cclags of individual .o objects:

clang-13: warning: -lm: 'linker' input unused [-Wunused-command-line-argument]
[ ... ]
  LD  samples/bpf/xdp_redirect_cpu
  LD  samples/bpf/xdp_redirect_map_multi
  LD  samples/bpf/xdp_redirect_map
  LD  samples/bpf/xdp_redirect
  LD  samples/bpf/xdp_monitor
/usr/bin/ld: samples/bpf/xdp_sample_user.o: in function `sample_summary_print':
xdp_sample_user.c:(.text+0x84c): undefined reference to `floor'
/usr/bin/ld: xdp_sample_user.c:(.text+0x870): undefined reference to `ceil'
/usr/bin/ld: xdp_sample_user.c:(.text+0x8cf): undefined reference to `floor'
/usr/bin/ld: xdp_sample_user.c:(.text+0x8f3): undefined reference to `ceil'
[ more ]

Specify '-lm' as ldflags for all xdp_sample_user.o users in the main
Makefile and remove it from ccflags of ^ in Makefile.target -- just
like it's done for all other samples. This works with all compilers.

Fixes: 6e1051a54e31 ("samples: bpf: Convert xdp_monitor to XDP samples helper")
Fixes: b926c55d856c ("samples: bpf: Convert xdp_redirect to XDP samples helper")
Fixes: e531a220cc59 ("samples: bpf: Convert xdp_redirect_cpu to XDP samples helper")
Fixes: bbe65865aa05 ("samples: bpf: Convert xdp_redirect_map to XDP samples helper")
Fixes: 594a116b2aa1 ("samples: bpf: Convert xdp_redirect_map_multi to XDP samples helper")
Signed-off-by: Alexander Lobakin &lt;alexandr.lobakin@intel.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20211203195004.5803-2-alexandr.lobakin@intel.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Clang (13) doesn't get the jokes about specifying libraries to link in
cclags of individual .o objects:

clang-13: warning: -lm: 'linker' input unused [-Wunused-command-line-argument]
[ ... ]
  LD  samples/bpf/xdp_redirect_cpu
  LD  samples/bpf/xdp_redirect_map_multi
  LD  samples/bpf/xdp_redirect_map
  LD  samples/bpf/xdp_redirect
  LD  samples/bpf/xdp_monitor
/usr/bin/ld: samples/bpf/xdp_sample_user.o: in function `sample_summary_print':
xdp_sample_user.c:(.text+0x84c): undefined reference to `floor'
/usr/bin/ld: xdp_sample_user.c:(.text+0x870): undefined reference to `ceil'
/usr/bin/ld: xdp_sample_user.c:(.text+0x8cf): undefined reference to `floor'
/usr/bin/ld: xdp_sample_user.c:(.text+0x8f3): undefined reference to `ceil'
[ more ]

Specify '-lm' as ldflags for all xdp_sample_user.o users in the main
Makefile and remove it from ccflags of ^ in Makefile.target -- just
like it's done for all other samples. This works with all compilers.

Fixes: 6e1051a54e31 ("samples: bpf: Convert xdp_monitor to XDP samples helper")
Fixes: b926c55d856c ("samples: bpf: Convert xdp_redirect to XDP samples helper")
Fixes: e531a220cc59 ("samples: bpf: Convert xdp_redirect_cpu to XDP samples helper")
Fixes: bbe65865aa05 ("samples: bpf: Convert xdp_redirect_map to XDP samples helper")
Fixes: 594a116b2aa1 ("samples: bpf: Convert xdp_redirect_map_multi to XDP samples helper")
Signed-off-by: Alexander Lobakin &lt;alexandr.lobakin@intel.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20211203195004.5803-2-alexandr.lobakin@intel.com
</pre>
</div>
</content>
</entry>
<entry>
<title>samples/bpf: Clean up samples/bpf build failes</title>
<updated>2021-12-02T23:23:40+00:00</updated>
<author>
<name>Andrii Nakryiko</name>
<email>andrii@kernel.org</email>
</author>
<published>2021-12-01T23:28:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=527024f7aeb683ce7ef49b07ef7ce9ecf015288d'/>
<id>527024f7aeb683ce7ef49b07ef7ce9ecf015288d</id>
<content type='text'>
Remove xdp_samples_user.o rule redefinition which generates Makefile
warning and instead override TPROGS_CFLAGS. This seems to work fine when
building inside selftests/bpf.

That was one big head-scratcher before I found that generic
Makefile.target hid this surprising specialization for for xdp_samples_user.o.

Main change is to use actual locally installed libbpf headers.

Also drop printk macro re-definition (not even used!).

Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20211201232824.3166325-8-andrii@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove xdp_samples_user.o rule redefinition which generates Makefile
warning and instead override TPROGS_CFLAGS. This seems to work fine when
building inside selftests/bpf.

That was one big head-scratcher before I found that generic
Makefile.target hid this surprising specialization for for xdp_samples_user.o.

Main change is to use actual locally installed libbpf headers.

Also drop printk macro re-definition (not even used!).

Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20211201232824.3166325-8-andrii@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2021-11-02T02:59:46+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2021-11-02T02:59:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b7b98f868987cd3e86c9bd9a6db048614933d7a0'/>
<id>b7b98f868987cd3e86c9bd9a6db048614933d7a0</id>
<content type='text'>
Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-11-01

We've added 181 non-merge commits during the last 28 day(s) which contain
a total of 280 files changed, 11791 insertions(+), 5879 deletions(-).

The main changes are:

1) Fix bpf verifier propagation of 64-bit bounds, from Alexei.

2) Parallelize bpf test_progs, from Yucong and Andrii.

3) Deprecate various libbpf apis including af_xdp, from Andrii, Hengqi, Magnus.

4) Improve bpf selftests on s390, from Ilya.

5) bloomfilter bpf map type, from Joanne.

6) Big improvements to JIT tests especially on Mips, from Johan.

7) Support kernel module function calls from bpf, from Kumar.

8) Support typeless and weak ksym in light skeleton, from Kumar.

9) Disallow unprivileged bpf by default, from Pawan.

10) BTF_KIND_DECL_TAG support, from Yonghong.

11) Various bpftool cleanups, from Quentin.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (181 commits)
  libbpf: Deprecate AF_XDP support
  kbuild: Unify options for BTF generation for vmlinux and modules
  selftests/bpf: Add a testcase for 64-bit bounds propagation issue.
  bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit.
  bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off.
  selftests/bpf: Fix also no-alu32 strobemeta selftest
  bpf: Add missing map_delete_elem method to bloom filter map
  selftests/bpf: Add bloom map success test for userspace calls
  bpf: Add alignment padding for "map_extra" + consolidate holes
  bpf: Bloom filter map naming fixups
  selftests/bpf: Add test cases for struct_ops prog
  bpf: Add dummy BPF STRUCT_OPS for test purpose
  bpf: Factor out helpers for ctx access checking
  bpf: Factor out a helper to prepare trampoline for struct_ops prog
  selftests, bpf: Fix broken riscv build
  riscv, libbpf: Add RISC-V (RV64) support to bpf_tracing.h
  tools, build: Add RISC-V to HOSTARCH parsing
  riscv, bpf: Increase the maximum number of iterations
  selftests, bpf: Add one test for sockmap with strparser
  selftests, bpf: Fix test_txmsg_ingress_parser error
  ...
====================

Link: https://lore.kernel.org/r/20211102013123.9005-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-11-01

We've added 181 non-merge commits during the last 28 day(s) which contain
a total of 280 files changed, 11791 insertions(+), 5879 deletions(-).

The main changes are:

1) Fix bpf verifier propagation of 64-bit bounds, from Alexei.

2) Parallelize bpf test_progs, from Yucong and Andrii.

3) Deprecate various libbpf apis including af_xdp, from Andrii, Hengqi, Magnus.

4) Improve bpf selftests on s390, from Ilya.

5) bloomfilter bpf map type, from Joanne.

6) Big improvements to JIT tests especially on Mips, from Johan.

7) Support kernel module function calls from bpf, from Kumar.

8) Support typeless and weak ksym in light skeleton, from Kumar.

9) Disallow unprivileged bpf by default, from Pawan.

10) BTF_KIND_DECL_TAG support, from Yonghong.

11) Various bpftool cleanups, from Quentin.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (181 commits)
  libbpf: Deprecate AF_XDP support
  kbuild: Unify options for BTF generation for vmlinux and modules
  selftests/bpf: Add a testcase for 64-bit bounds propagation issue.
  bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit.
  bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off.
  selftests/bpf: Fix also no-alu32 strobemeta selftest
  bpf: Add missing map_delete_elem method to bloom filter map
  selftests/bpf: Add bloom map success test for userspace calls
  bpf: Add alignment padding for "map_extra" + consolidate holes
  bpf: Bloom filter map naming fixups
  selftests/bpf: Add test cases for struct_ops prog
  bpf: Add dummy BPF STRUCT_OPS for test purpose
  bpf: Factor out helpers for ctx access checking
  bpf: Factor out a helper to prepare trampoline for struct_ops prog
  selftests, bpf: Fix broken riscv build
  riscv, libbpf: Add RISC-V (RV64) support to bpf_tracing.h
  tools, build: Add RISC-V to HOSTARCH parsing
  riscv, bpf: Increase the maximum number of iterations
  selftests, bpf: Add one test for sockmap with strparser
  selftests, bpf: Fix test_txmsg_ingress_parser error
  ...
====================

Link: https://lore.kernel.org/r/20211102013123.9005-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>samples: bpf: Suppress readelf stderr when probing for BTF support</title>
<updated>2021-10-21T22:09:23+00:00</updated>
<author>
<name>Pu Lehui</name>
<email>pulehui@huawei.com</email>
</author>
<published>2021-10-21T12:39:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=44ce0ac11e4e6dd1aee2e41e7d74f95f3b961cfb'/>
<id>44ce0ac11e4e6dd1aee2e41e7d74f95f3b961cfb</id>
<content type='text'>
When compiling bpf samples, the following warning appears:

readelf: Error: Missing knowledge of 32-bit reloc types used in DWARF
sections of machine number 247
readelf: Warning: unable to apply unsupported reloc type 10 to section
.debug_info
readelf: Warning: unable to apply unsupported reloc type 1 to section
.debug_info
readelf: Warning: unable to apply unsupported reloc type 10 to section
.debug_info

Same problem was mentioned in commit 2f0921262ba9 ("selftests/bpf:
suppress readelf stderr when probing for BTF support"), let's use
readelf that supports btf.

Signed-off-by: Pu Lehui &lt;pulehui@huawei.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20211021123913.48833-1-pulehui@huawei.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When compiling bpf samples, the following warning appears:

readelf: Error: Missing knowledge of 32-bit reloc types used in DWARF
sections of machine number 247
readelf: Warning: unable to apply unsupported reloc type 10 to section
.debug_info
readelf: Warning: unable to apply unsupported reloc type 1 to section
.debug_info
readelf: Warning: unable to apply unsupported reloc type 10 to section
.debug_info

Same problem was mentioned in commit 2f0921262ba9 ("selftests/bpf:
suppress readelf stderr when probing for BTF support"), let's use
readelf that supports btf.

Signed-off-by: Pu Lehui &lt;pulehui@huawei.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: John Fastabend &lt;john.fastabend@gmail.com&gt;
Link: https://lore.kernel.org/bpf/20211021123913.48833-1-pulehui@huawei.com
</pre>
</div>
</content>
</entry>
<entry>
<title>samples/bpf: Do not FORCE-recompile libbpf</title>
<updated>2021-10-08T19:02:36+00:00</updated>
<author>
<name>Quentin Monnet</name>
<email>quentin@isovalent.com</email>
</author>
<published>2021-10-07T19:44:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a60d24e7400247bf21cac451f28961ac800756c6'/>
<id>a60d24e7400247bf21cac451f28961ac800756c6</id>
<content type='text'>
In samples/bpf/Makefile, libbpf has a FORCE dependency that force it to
be rebuilt. I read this as a way to keep the library up-to-date, given
that we do not have, in samples/bpf, a list of the source files for
libbpf itself. However, a better approach would be to use the
"$(wildcard ...)" function from make, and to have libbpf depend on all
the .c and .h files in its directory. This is what samples/bpf/Makefile
does for bpftool, and also what the BPF selftests' Makefile does for
libbpf.

Let's update the Makefile to avoid rebuilding libbpf all the time (and
bpftool on top of it).

Signed-off-by: Quentin Monnet &lt;quentin@isovalent.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20211007194438.34443-11-quentin@isovalent.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In samples/bpf/Makefile, libbpf has a FORCE dependency that force it to
be rebuilt. I read this as a way to keep the library up-to-date, given
that we do not have, in samples/bpf, a list of the source files for
libbpf itself. However, a better approach would be to use the
"$(wildcard ...)" function from make, and to have libbpf depend on all
the .c and .h files in its directory. This is what samples/bpf/Makefile
does for bpftool, and also what the BPF selftests' Makefile does for
libbpf.

Let's update the Makefile to avoid rebuilding libbpf all the time (and
bpftool on top of it).

Signed-off-by: Quentin Monnet &lt;quentin@isovalent.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20211007194438.34443-11-quentin@isovalent.com
</pre>
</div>
</content>
</entry>
<entry>
<title>samples/bpf: Install libbpf headers when building</title>
<updated>2021-10-08T19:00:20+00:00</updated>
<author>
<name>Quentin Monnet</name>
<email>quentin@isovalent.com</email>
</author>
<published>2021-10-07T19:44:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3f7a3318a7c60947e27be372950840a5eab976d0'/>
<id>3f7a3318a7c60947e27be372950840a5eab976d0</id>
<content type='text'>
API headers from libbpf should not be accessed directly from the source
directory. Instead, they should be exported with "make install_headers".
Make sure that samples/bpf/Makefile installs the headers properly when
building.

The object compiled from and exported by libbpf are now placed into a
subdirectory of sample/bpf/ instead of remaining in tools/lib/bpf/. We
attempt to remove this directory on "make clean". However, the "clean"
target re-enters the samples/bpf/ directory from the root of the
repository ("$(MAKE) -C ../../ M=$(CURDIR) clean"), in such a way that
$(srctree) and $(src) are not defined, making it impossible to use
$(LIBBPF_OUTPUT) and $(LIBBPF_DESTDIR) in the recipe. So we only attempt
to clean $(CURDIR)/libbpf, which is the default value.

Add a dependency on libbpf's headers for the $(TRACE_HELPERS).

We also change the output directory for bpftool, to place the generated
objects under samples/bpf/bpftool/ instead of building in bpftool's
directory directly. Doing so, we make sure bpftool reuses the libbpf
library previously compiled and installed.

Signed-off-by: Quentin Monnet &lt;quentin@isovalent.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20211007194438.34443-10-quentin@isovalent.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
API headers from libbpf should not be accessed directly from the source
directory. Instead, they should be exported with "make install_headers".
Make sure that samples/bpf/Makefile installs the headers properly when
building.

The object compiled from and exported by libbpf are now placed into a
subdirectory of sample/bpf/ instead of remaining in tools/lib/bpf/. We
attempt to remove this directory on "make clean". However, the "clean"
target re-enters the samples/bpf/ directory from the root of the
repository ("$(MAKE) -C ../../ M=$(CURDIR) clean"), in such a way that
$(srctree) and $(src) are not defined, making it impossible to use
$(LIBBPF_OUTPUT) and $(LIBBPF_DESTDIR) in the recipe. So we only attempt
to clean $(CURDIR)/libbpf, which is the default value.

Add a dependency on libbpf's headers for the $(TRACE_HELPERS).

We also change the output directory for bpftool, to place the generated
objects under samples/bpf/bpftool/ instead of building in bpftool's
directory directly. Doing so, we make sure bpftool reuses the libbpf
library previously compiled and installed.

Signed-off-by: Quentin Monnet &lt;quentin@isovalent.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20211007194438.34443-10-quentin@isovalent.com
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Use $(pound) instead of \# in Makefiles</title>
<updated>2021-10-06T19:34:02+00:00</updated>
<author>
<name>Quentin Monnet</name>
<email>quentin@isovalent.com</email>
</author>
<published>2021-10-06T11:10:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=929bef467771d4d5a22b9edb51a2025dc0e49113'/>
<id>929bef467771d4d5a22b9edb51a2025dc0e49113</id>
<content type='text'>
Recent-ish versions of make do no longer consider number signs ("#") as
comment symbols when they are inserted inside of a macro reference or in
a function invocation. In such cases, the symbols should not be escaped.

There are a few occurrences of "\#" in libbpf's and samples' Makefiles.
In the former, the backslash is harmless, because grep associates no
particular meaning to the escaped symbol and reads it as a regular "#".
In samples' Makefile, recent versions of make will pass the backslash
down to the compiler, making the probe fail all the time and resulting
in the display of a warning about "make headers_install" being required,
even after headers have been installed.

A similar issue has been addressed at some other locations by commit
9564a8cf422d ("Kbuild: fix # escaping in .cmd files for future Make").
Let's address it for libbpf's and samples' Makefiles in the same
fashion, by using a "$(pound)" variable (pulled from
tools/scripts/Makefile.include for libbpf, or re-defined for the
samples).

Reference for the change in make:
https://git.savannah.gnu.org/cgit/make.git/commit/?id=c6966b323811c37acedff05b57

Fixes: 2f3830412786 ("libbpf: Make libbpf_version.h non-auto-generated")
Fixes: 07c3bbdb1a9b ("samples: bpf: print a warning about headers_install")
Signed-off-by: Quentin Monnet &lt;quentin@isovalent.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20211006111049.20708-1-quentin@isovalent.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Recent-ish versions of make do no longer consider number signs ("#") as
comment symbols when they are inserted inside of a macro reference or in
a function invocation. In such cases, the symbols should not be escaped.

There are a few occurrences of "\#" in libbpf's and samples' Makefiles.
In the former, the backslash is harmless, because grep associates no
particular meaning to the escaped symbol and reads it as a regular "#".
In samples' Makefile, recent versions of make will pass the backslash
down to the compiler, making the probe fail all the time and resulting
in the display of a warning about "make headers_install" being required,
even after headers have been installed.

A similar issue has been addressed at some other locations by commit
9564a8cf422d ("Kbuild: fix # escaping in .cmd files for future Make").
Let's address it for libbpf's and samples' Makefiles in the same
fashion, by using a "$(pound)" variable (pulled from
tools/scripts/Makefile.include for libbpf, or re-defined for the
samples).

Reference for the change in make:
https://git.savannah.gnu.org/cgit/make.git/commit/?id=c6966b323811c37acedff05b57

Fixes: 2f3830412786 ("libbpf: Make libbpf_version.h non-auto-generated")
Fixes: 07c3bbdb1a9b ("samples: bpf: print a warning about headers_install")
Signed-off-by: Quentin Monnet &lt;quentin@isovalent.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20211006111049.20708-1-quentin@isovalent.com
</pre>
</div>
</content>
</entry>
<entry>
<title>samples: bpf: Fix vmlinux.h generation for XDP samples</title>
<updated>2021-09-29T00:21:35+00:00</updated>
<author>
<name>Kumar Kartikeya Dwivedi</name>
<email>memxor@gmail.com</email>
</author>
<published>2021-09-28T05:46:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=571fa247ab411f3233eeaaf837c6e646a513b9f8'/>
<id>571fa247ab411f3233eeaaf837c6e646a513b9f8</id>
<content type='text'>
Generate vmlinux.h only from the in-tree vmlinux, and remove enum
declarations that would cause a build failure in case of version
mismatches.

There are now two options when building the samples:
1. Compile the kernel to use in-tree vmlinux for vmlinux.h
2. Override VMLINUX_BTF for samples using something like this:
   make VMLINUX_BTF=/sys/kernel/btf/vmlinux -C samples/bpf

This change was tested with relative builds, e.g. cases like:
 * make O=build -C samples/bpf
 * make KBUILD_OUTPUT=build -C samples/bpf
 * make -C samples/bpf
 * cd samples/bpf &amp;&amp; make

When a suitable VMLINUX_BTF is not found, the following message is
printed:
/home/kkd/src/linux/samples/bpf/Makefile:333: *** Cannot find a vmlinux
for VMLINUX_BTF at any of "  ./vmlinux", build the kernel or set
VMLINUX_BTF variable.  Stop.

Fixes: 384b6b3bbf0d (samples: bpf: Add vmlinux.h generation support)
Signed-off-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Link: https://lore.kernel.org/bpf/20210928054608.1799021-1-memxor@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Generate vmlinux.h only from the in-tree vmlinux, and remove enum
declarations that would cause a build failure in case of version
mismatches.

There are now two options when building the samples:
1. Compile the kernel to use in-tree vmlinux for vmlinux.h
2. Override VMLINUX_BTF for samples using something like this:
   make VMLINUX_BTF=/sys/kernel/btf/vmlinux -C samples/bpf

This change was tested with relative builds, e.g. cases like:
 * make O=build -C samples/bpf
 * make KBUILD_OUTPUT=build -C samples/bpf
 * make -C samples/bpf
 * cd samples/bpf &amp;&amp; make

When a suitable VMLINUX_BTF is not found, the following message is
printed:
/home/kkd/src/linux/samples/bpf/Makefile:333: *** Cannot find a vmlinux
for VMLINUX_BTF at any of "  ./vmlinux", build the kernel or set
VMLINUX_BTF variable.  Stop.

Fixes: 384b6b3bbf0d (samples: bpf: Add vmlinux.h generation support)
Signed-off-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Link: https://lore.kernel.org/bpf/20210928054608.1799021-1-memxor@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>samples: bpf: Convert xdp_redirect_map_multi to XDP samples helper</title>
<updated>2021-08-24T21:48:42+00:00</updated>
<author>
<name>Kumar Kartikeya Dwivedi</name>
<email>memxor@gmail.com</email>
</author>
<published>2021-08-21T00:20:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=594a116b2aa1985dbb5318c2be39b64b74ebff84'/>
<id>594a116b2aa1985dbb5318c2be39b64b74ebff84</id>
<content type='text'>
Use the libbpf skeleton facility and other utilities provided by XDP
samples helper. Also adapt to change of type of mac address map, so that
no resizing is required.

Add a new flag for sample mask that skips priting the
from_device-&gt;to_device heading for each line, as xdp_redirect_map_multi
may have two devices but the flow of data may be bidirectional, so the
output would be confusing.

Signed-off-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20210821002010.845777-23-memxor@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use the libbpf skeleton facility and other utilities provided by XDP
samples helper. Also adapt to change of type of mac address map, so that
no resizing is required.

Add a new flag for sample mask that skips priting the
from_device-&gt;to_device heading for each line, as xdp_redirect_map_multi
may have two devices but the flow of data may be bidirectional, so the
output would be confusing.

Signed-off-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20210821002010.845777-23-memxor@gmail.com
</pre>
</div>
</content>
</entry>
</feed>
