linux.git/samples/bpf/Makefile, branch v5.15.114

samples: bpf: Don't fail for a missing VMLINUX_BTF when VMLINUX_H is provided

2022-06-09T08:22:55+00:00

[ 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 
Reported-by: Veronika Kabatova 
Signed-off-by: Jerome Marchand 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20220507161635.2219052-1-jmarchan@redhat.com
Signed-off-by: Sasha Levin

samples: bpf: Fix xdp_sample_user.o linking with Clang

2022-01-27T10:03:29+00:00

[ Upstream commit e64fbcaa7a666f16329b1c67af15ea501bc84586 ]

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 
Signed-off-by: Andrii Nakryiko 
Acked-by: Kumar Kartikeya Dwivedi 
Link: https://lore.kernel.org/bpf/20211203195004.5803-2-alexandr.lobakin@intel.com
Signed-off-by: Sasha Levin

samples/bpf: Clean up samples/bpf build failes

2022-01-27T10:03:29+00:00

[ Upstream commit 527024f7aeb683ce7ef49b07ef7ce9ecf015288d ]

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 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20211201232824.3166325-8-andrii@kernel.org
Signed-off-by: Sasha Levin

samples/bpf: Install libbpf headers when building

2022-01-27T10:03:28+00:00

[ Upstream commit 3f7a3318a7c60947e27be372950840a5eab976d0 ]

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 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20211007194438.34443-10-quentin@isovalent.com
Signed-off-by: Sasha Levin

samples: bpf: Fix vmlinux.h generation for XDP samples

2021-09-29T00:21:35+00:00

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 && 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 
Signed-off-by: Andrii Nakryiko 
Acked-by: Toke Høiland-Jørgensen 
Link: https://lore.kernel.org/bpf/20210928054608.1799021-1-memxor@gmail.com

samples: bpf: Convert xdp_redirect_map_multi to XDP samples helper

2021-08-24T21:48:42+00:00

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->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 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20210821002010.845777-23-memxor@gmail.com

samples: bpf: Convert xdp_redirect_map_multi_kern.o to XDP samples helper

2021-08-24T21:48:42+00:00

One of the notable changes is using a BPF_MAP_TYPE_HASH instead of array
map to store mac addresses of devices, as the resizing behavior was
based on max_ifindex, which unecessarily maximized the capacity of map
beyond what was needed.

Signed-off-by: Kumar Kartikeya Dwivedi 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20210821002010.845777-22-memxor@gmail.com

samples: bpf: Convert xdp_redirect_map to XDP samples helper

2021-08-24T21:48:42+00:00

Use the libbpf skeleton facility and other utilities provided by XDP
samples helper.

Since get_mac_addr is already provided by XDP samples helper, we drop
it. Also convert to XDP samples helper similar to prior samples to
minimize duplication of code.

Signed-off-by: Kumar Kartikeya Dwivedi 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20210821002010.845777-21-memxor@gmail.com

samples: bpf: Convert xdp_redirect_map_kern.o to XDP samples helper

2021-08-24T21:48:42+00:00

Also update it to use consistent SEC("xdp") and SEC("xdp_devmap")
naming, and use global variable instead of BPF map for copying the mac
address.

Signed-off-by: Kumar Kartikeya Dwivedi 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20210821002010.845777-20-memxor@gmail.com

samples: bpf: Convert xdp_redirect_cpu to XDP samples helper

2021-08-24T21:48:42+00:00

Use the libbpf skeleton facility and other utilities provided by XDP
samples helper.

Similar to xdp_monitor, xdp_redirect_cpu was quite featureful except a
few minor omissions (e.g. redirect errno reporting). All of these have
been moved to XDP samples helper, hence drop the unneeded code and
convert to usage of helpers provided by it.

One of the important changes here is dropping of mprog-disable option,
as we make that the default. Also, we support built-in programs for some
common actions on the packet when it reaches kthread (pass, drop,
redirect to device). If the user still needs to install a custom
program, they can still supply a BPF object, however the program should
be suitably tagged with SEC("xdp_cpumap") annotation so that the
expected attach type is correct when updating our cpumap map element.

Signed-off-by: Kumar Kartikeya Dwivedi 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20210821002010.845777-19-memxor@gmail.com