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2020-06-16bpf, xdp, samples: Fix null pointer dereference in *_user codeGaurav Singh1-10/+3
Memset on the pointer right after malloc can cause a NULL pointer deference if it failed to allocate memory. A simple fix is to replace malloc()/memset() pair with a simple call to calloc(). Fixes: 0fca931a6f21 ("samples/bpf: program demonstrating access to xdp_rxq_info") Signed-off-by: Gaurav Singh <gaurav1086@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com>
2020-01-21samples/bpf: Use consistent include paths for libbpfToke Høiland-Jørgensen1-2/+2
Fix all files in samples/bpf to include libbpf header files with the bpf/ prefix, to be consistent with external users of the library. Also ensure that all includes of exported libbpf header files (those that are exported on 'make install' of the library) use bracketed includes instead of quoted. To make sure no new files are introduced that doesn't include the bpf/ prefix in its include, remove tools/lib/bpf from the include path entirely, and use tools/lib instead. Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk
2019-12-16samples/bpf: Attach XDP programs in driver mode by defaultToke Høiland-Jørgensen1-0/+4
When attaching XDP programs, userspace can set flags to request the attach mode (generic/SKB mode, driver mode or hw offloaded mode). If no such flags are requested, the kernel will attempt to attach in driver mode, and then silently fall back to SKB mode if this fails. The silent fallback is a major source of user confusion, as users will try to load a program on a device without XDP support, and instead of an error they will get the silent fallback behaviour, not notice, and then wonder why performance is not what they were expecting. In an attempt to combat this, let's switch all the samples to default to explicitly requesting driver-mode attach. As part of this, ensure that all the userspace utilities have a switch to enable SKB mode. For those that have a switch to request driver mode, keep it but turn it into a no-op. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: David Ahern <dsahern@gmail.com> Link: https://lore.kernel.org/bpf/20191216110742.364456-1-toke@redhat.com
2019-12-05samples/bpf: Fix broken xdp_rxq_info due to map order assumptionsJesper Dangaard Brouer1-3/+3
In the days of using bpf_load.c the order in which the 'maps' sections were defines in BPF side (*_kern.c) file, were used by userspace side to identify the map via using the map order as an index. In effect the order-index is created based on the order the maps sections are stored in the ELF-object file, by the LLVM compiler. This have also carried over in libbpf via API bpf_map__next(NULL, obj) to extract maps in the order libbpf parsed the ELF-object file. When BTF based maps were introduced a new section type ".maps" were created. I found that the LLVM compiler doesn't create the ".maps" sections in the order they are defined in the C-file. The order in the ELF file is based on the order the map pointer is referenced in the code. This combination of changes lead to xdp_rxq_info mixing up the map file-descriptors in userspace, resulting in very broken behaviour, but without warning the user. This patch fix issue by instead using bpf_object__find_map_by_name() to find maps via their names. (Note, this is the ELF name, which can be longer than the name the kernel retains). Fixes: be5bca44aa6b ("samples: bpf: convert some XDP samples from bpf_load to libbpf") Fixes: 451d1dc886b5 ("samples: bpf: update map definition to new syntax BTF-defined map") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/157529025128.29832.5953245340679936909.stgit@firesoul
2019-11-09samples: bpf: Update outdated error messageDaniel T. Lee1-3/+3
Currently, under samples, several methods are being used to load bpf program. Since using libbpf is preferred solution, lots of previously used 'load_bpf_file' from bpf_load are replaced with 'bpf_prog_load_xattr' from libbpf. But some of the error messages still show up as 'load_bpf_file' instead of 'bpf_prog_load_xattr'. This commit fixes outdated errror messages under samples and fixes some code style issues. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20191107005153.31541-2-danieltimlee@gmail.com
2019-06-18samples: bpf: refactor header include pathDaniel T. Lee1-2/+2
Currently, header inclusion in each file is inconsistent. For example, "libbpf.h" header is included as multiple ways. #include "bpf/libbpf.h" #include "libbpf.h" Due to commit b552d33c80a9 ("samples/bpf: fix include path in Makefile"), $(srctree)/tools/lib/bpf/ path had been included during build, path "bpf/" in header isn't necessary anymore. This commit removes path "bpf/" in header inclusion. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-02samples/bpf: Check the prog id before exitingMaciej Fijalkowski1-5/+28
Check the program id within the signal handler on polling xdp samples that were previously converted to libbpf usage. Avoid the situation of unloading the program that was not attached by sample that is exiting. Handle also the case where bpf_get_link_xdp_id didn't exit with an error but the xdp program was not found on an interface. Reported-by: Michal Papaj <michal.papaj@intel.com> Reported-by: Jakub Spizewski <jakub.spizewski@intel.com> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-02samples/bpf: Add a "force" flag to XDP samplesMaciej Fijalkowski1-2/+6
Make xdp samples consistent with iproute2 behavior and set the XDP_FLAGS_UPDATE_IF_NOEXIST by default when setting the xdp program on interface. Provide an option for user to force the program loading, which as a result will not include the mentioned flag in bpf_set_link_xdp_fd call. Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-16samples/bpf: all XDP samples should unload xdp/bpf prog on SIGTERMJesper Dangaard Brouer1-1/+2
It is common XDP practice to unload/deattach the XDP bpf program, when the XDP sample program is Ctrl-C interrupted (SIGINT) or killed (SIGTERM). The samples/bpf programs xdp_redirect_cpu and xdp_rxq_info, forgot to trap signal SIGTERM (which is the default signal used by the kill command). This was discovered by Red Hat QA, which automated scripts depend on killing the XDP sample program after a timeout period. Fixes: fad3917e361b ("samples/bpf: add cpumap sample program xdp_redirect_cpu") Fixes: 0fca931a6f21 ("samples/bpf: program demonstrating access to xdp_rxq_info") Reported-by: Jean-Tsung Hsiao <jhsiao@redhat.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-06-29samples/bpf: xdp_rxq_info action XDP_TX must adjust MAC-addrsJesper Dangaard Brouer1-0/+11
XDP_TX requires also changing the MAC-addrs, else some hardware may drop the TX packet before reaching the wire. This was observed with driver mlx5. If xdp_rxq_info select --action XDP_TX the swapmac functionality is activated. It is also possible to manually enable via cmdline option --swapmac. This is practical if wanting to measure the overhead of writing/updating payload for other action types. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-06-29samples/bpf: extend xdp_rxq_info to read packet payloadJesper Dangaard Brouer1-6/+28
There is a cost associated with reading the packet data payload that this test ignored. Add option --read to allow enabling reading part of the payload. This sample/tool helps us analyse an issue observed with a NIC mlx5 (ConnectX-5 Ex) and an Intel(R) Xeon(R) CPU E5-1650 v4. With no_touch of data: Running XDP on dev:mlx5p1 (ifindex:8) action:XDP_DROP options:no_touch XDP stats CPU pps issue-pps XDP-RX CPU 0 14,465,157 0 XDP-RX CPU 1 14,464,728 0 XDP-RX CPU 2 14,465,283 0 XDP-RX CPU 3 14,465,282 0 XDP-RX CPU 4 14,464,159 0 XDP-RX CPU 5 14,465,379 0 XDP-RX CPU total 86,789,992 When not touching data, we observe that the CPUs have idle cycles. When reading data the CPUs are 100% busy in softirq. With reading data: Running XDP on dev:mlx5p1 (ifindex:8) action:XDP_DROP options:read XDP stats CPU pps issue-pps XDP-RX CPU 0 9,620,639 0 XDP-RX CPU 1 9,489,843 0 XDP-RX CPU 2 9,407,854 0 XDP-RX CPU 3 9,422,289 0 XDP-RX CPU 4 9,321,959 0 XDP-RX CPU 5 9,395,242 0 XDP-RX CPU total 56,657,828 The effect seen above is a result of cache-misses occuring when more RXQs are being used. Based on perf-event observations, our conclusion is that the CPUs DDIO (Direct Data I/O) choose to deliver packet into main memory, instead of L3-cache. We also found, that this can be mitigated by either using less RXQs or by reducing NICs the RX-ring size. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11samples: bpf: convert some XDP samples from bpf_load to libbpfJakub Kicinski1-15/+31
Now that we can use full powers of libbpf in BPF samples, we should perhaps make the simplest XDP programs not depend on bpf_load helpers. This way newcomers will be exposed to the recommended library from the start. Use of bpf_prog_load_xattr() will also make it trivial to later on request offload of the programs by simply adding ifindex to the xattr. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-03samples/bpf: use bpf_set_link_xdp_fdEric Leblond1-2/+2
Use bpf_set_link_xdp_fd instead of set_link_xdp_fd to remove some code duplication and benefit of netlink ext ack errors message. Signed-off-by: Eric Leblond <eric@regit.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-06samples/bpf: program demonstrating access to xdp_rxq_infoJesper Dangaard Brouer1-0/+531
This sample program can be used for monitoring and reporting how many packets per sec (pps) are received per NIC RX queue index and which CPU processed the packet. In itself it is a useful tool for quickly identifying RSS imbalance issues, see below. The default XDP action is XDP_PASS in-order to provide a monitor mode. For benchmarking purposes it is possible to specify other XDP actions on the cmdline --action. Output below shows an imbalance RSS case where most RXQ's deliver to CPU-0 while CPU-2 only get packets from a single RXQ. Looking at things from a CPU level the two CPUs are processing approx the same amount, BUT looking at the rx_queue_index levels it is clear that RXQ-2 receive much better service, than other RXQs which all share CPU-0. Running XDP on dev:i40e1 (ifindex:3) action:XDP_PASS XDP stats CPU pps issue-pps XDP-RX CPU 0 900,473 0 XDP-RX CPU 2 906,921 0 XDP-RX CPU total 1,807,395 RXQ stats RXQ:CPU pps issue-pps rx_queue_index 0:0 180,098 0 rx_queue_index 0:sum 180,098 rx_queue_index 1:0 180,098 0 rx_queue_index 1:sum 180,098 rx_queue_index 2:2 906,921 0 rx_queue_index 2:sum 906,921 rx_queue_index 3:0 180,098 0 rx_queue_index 3:sum 180,098 rx_queue_index 4:0 180,082 0 rx_queue_index 4:sum 180,082 rx_queue_index 5:0 180,093 0 rx_queue_index 5:sum 180,093 Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>