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2020-10-02Merge branch 'master' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2020-10-02 1) Add a full xfrm compatible layer for 32-bit applications on 64-bit kernels. From Dmitry Safonov. Please pull or let me know if there are problems. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf-next 2020-10-01 The following pull-request contains BPF updates for your *net-next* tree. We've added 90 non-merge commits during the last 8 day(s) which contain a total of 103 files changed, 7662 insertions(+), 1894 deletions(-). Note that once bpf(/net) tree gets merged into net-next, there will be a small merge conflict in tools/lib/bpf/btf.c between commit 1245008122d7 ("libbpf: Fix native endian assumption when parsing BTF") from the bpf tree and the commit 3289959b97ca ("libbpf: Support BTF loading and raw data output in both endianness") from the bpf-next tree. Correct resolution would be to stick with bpf-next, it should look like: [...] /* check BTF magic */ if (fread(&magic, 1, sizeof(magic), f) < sizeof(magic)) { err = -EIO; goto err_out; } if (magic != BTF_MAGIC && magic != bswap_16(BTF_MAGIC)) { /* definitely not a raw BTF */ err = -EPROTO; goto err_out; } /* get file size */ [...] The main changes are: 1) Add bpf_snprintf_btf() and bpf_seq_printf_btf() helpers to support displaying BTF-based kernel data structures out of BPF programs, from Alan Maguire. 2) Speed up RCU tasks trace grace periods by a factor of 50 & fix a few race conditions exposed by it. It was discussed to take these via BPF and networking tree to get better testing exposure, from Paul E. McKenney. 3) Support multi-attach for freplace programs, needed for incremental attachment of multiple XDP progs using libxdp dispatcher model, from Toke Høiland-Jørgensen. 4) libbpf support for appending new BTF types at the end of BTF object, allowing intrusive changes of prog's BTF (useful for future linking), from Andrii Nakryiko. 5) Several BPF helper improvements e.g. avoid atomic op in cookie generator and add a redirect helper into neighboring subsys, from Daniel Borkmann. 6) Allow map updates on sockmaps from bpf_iter context in order to migrate sockmaps from one to another, from Lorenz Bauer. 7) Fix 32 bit to 64 bit assignment from latest alu32 bounds tracking which caused a verifier issue due to type downgrade to scalar, from John Fastabend. 8) Follow-up on tail-call support in BPF subprogs which optimizes x64 JIT prologue and epilogue sections, from Maciej Fijalkowski. 9) Add an option to perf RB map to improve sharing of event entries by avoiding remove- on-close behavior. Also, add BPF_PROG_TEST_RUN for raw_tracepoint, from Song Liu. 10) Fix a crash in AF_XDP's socket_release when memory allocation for UMEMs fails, from Magnus Karlsson. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-30selftests/bpf: Add tests for BPF_F_PRESERVE_ELEMSSong Liu
Add tests for perf event array with and without BPF_F_PRESERVE_ELEMS. Add a perf event to array via fd mfd. Without BPF_F_PRESERVE_ELEMS, the perf event is removed when mfd is closed. With BPF_F_PRESERVE_ELEMS, the perf event is removed when the map is freed. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200930224927.1936644-3-songliubraving@fb.com
2020-09-30bpf: Introduce BPF_F_PRESERVE_ELEMS for perf event arraySong Liu
Currently, perf event in perf event array is removed from the array when the map fd used to add the event is closed. This behavior makes it difficult to the share perf events with perf event array. Introduce perf event map that keeps the perf event open with a new flag BPF_F_PRESERVE_ELEMS. With this flag set, perf events in the array are not removed when the original map fd is closed. Instead, the perf event will stay in the map until 1) it is explicitly removed from the array; or 2) the array is freed. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200930224927.1936644-2-songliubraving@fb.com
2020-09-30selftests/bpf: Fix alignment of .BTF_idsJean-Philippe Brucker
Fix a build failure on arm64, due to missing alignment information for the .BTF_ids section: resolve_btfids.test.o: in function `test_resolve_btfids': tools/testing/selftests/bpf/prog_tests/resolve_btfids.c:140:(.text+0x29c): relocation truncated to fit: R_AARCH64_LDST32_ABS_LO12_NC against `.BTF_ids' ld: tools/testing/selftests/bpf/prog_tests/resolve_btfids.c:140: warning: one possible cause of this error is that the symbol is being referenced in the indicated code as if it had a larger alignment than was declared where it was defined In vmlinux, the .BTF_ids section is aligned to 4 bytes by vmlinux.lds.h. In test_progs however, .BTF_ids doesn't have alignment constraints. The arm64 linker expects the btf_id_set.cnt symbol, a u32, to be naturally aligned but finds it misaligned and cannot apply the relocation. Enforce alignment of .BTF_ids to 4 bytes. Fixes: cd04b04de119 ("selftests/bpf: Add set test to resolve_btfids") Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> Link: https://lore.kernel.org/bpf/20200930093559.2120126-1-jean-philippe@linaro.org
2020-09-30selftests: net: Add drop monitor testIdo Schimmel
Test that drop monitor correctly captures both software and hardware originated packet drops. # ./drop_monitor_tests.sh Software drops test TEST: Capturing active software drops [ OK ] TEST: Capturing inactive software drops [ OK ] Hardware drops test TEST: Capturing active hardware drops [ OK ] TEST: Capturing inactive hardware drops [ OK ] Tests passed: 4 Tests failed: 0 Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-30selftests: mlxsw: Add a PFC testPetr Machata
Add a test for PFC. Runs 10MB of traffic through a bottleneck and checks that none of it gets lost. Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-30selftests: mlxsw: Add headroom handling testPetr Machata
Add a test for headroom configuration. This covers projection of ETS configuration to ingress, PFC, adjustments for MTU, the qdisc / TC mode and the effect of egress SPAN session on buffer configuration. Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-30selftests: mlxsw: qos_lib: Add a wrapper for running mlnx_qosPetr Machata
mlnx_qos is a script for configuration of DCB. Despite the name it is not actually Mellanox-specific in any way. It is currently the only ad-hoc tool available (in contrast to a daemon that manages an interface on an ongoing basis). However, it is very verbose and parsing out error messages is not really possible. Add a wrapper that makes it easier to use the tool. Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-30selftests: forwarding: devlink_lib: Support port-less topologiesPetr Machata
Some selftests may not need any actual ports. Technically those are not forwarding selftests, but devlink_lib can still be handy. Fall back on NETIF_NO_CABLE in those cases. Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-30selftests: forwarding: devlink_lib: Add devlink_cell_size_get()Petr Machata
Add a helper that answers the cell size of the devlink device. Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-30selftests: forwarding: devlink_lib: Split devlink_..._set() into save & setPetr Machata
Changing pool type from static to dynamic causes reinterpretation of threshold values. They therefore need to be saved before pool type is changed, then the pool type can be changed, and then the new values need to be set up. For that reason, set cannot subsume save, because it would be saving the wrong thing, with possibly a nonsensical value, and restore would then fail to restore the nonsensical value. Thus extract a _save() from each of the relevant _set()'s. This way it is possible to save everything up front, then to tweak it, and then restore in the required order. Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-30selftests/bpf: Test "incremental" btf_dump in C formatAndrii Nakryiko
Add test validating that btf_dump works fine with BTFs that are modified and incrementally generated. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200929232843.1249318-5-andriin@fb.com
2020-09-30libbpf: Make btf_dump work with modifiable BTFAndrii Nakryiko
Ensure that btf_dump can accommodate new BTF types being appended to BTF instance after struct btf_dump was created. This came up during attemp to use btf_dump for raw type dumping in selftests, but given changes are not excessive, it's good to not have any gotchas in API usage, so I decided to support such use case in general. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200929232843.1249318-2-andriin@fb.com
2020-09-30bpf, selftests: Add redirect_neigh selftestDaniel Borkmann
Add a small test that exercises the new redirect_neigh() helper for the IPv4 and IPv6 case. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/0fc7d9c5f9a6cc1c65b0d3be83b44b1ec9889f43.1601477936.git.daniel@iogearbox.net
2020-09-30bpf, selftests: Use bpf_tail_call_static where appropriateDaniel Borkmann
For those locations where we use an immediate tail call map index use the newly added bpf_tail_call_static() helper. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/3cfb2b799a62d22c6e7ae5897c23940bdcc24cbc.1601477936.git.daniel@iogearbox.net
2020-09-30bpf, libbpf: Add bpf_tail_call_static helper for bpf programsDaniel Borkmann
Port of tail_call_static() helper function from Cilium's BPF code base [0] to libbpf, so others can easily consume it as well. We've been using this in production code for some time now. The main idea is that we guarantee that the kernel's BPF infrastructure and JIT (here: x86_64) can patch the JITed BPF insns with direct jumps instead of having to fall back to using expensive retpolines. By using inline asm, we guarantee that the compiler won't merge the call from different paths with potentially different content of r2/r3. We're also using Cilium's __throw_build_bug() macro (here as: __bpf_unreachable()) in different places as a neat trick to trigger compilation errors when compiler does not remove code at compilation time. This works for the BPF back end as it does not implement the __builtin_trap(). [0] https://github.com/cilium/cilium/commit/f5537c26020d5297b70936c6b7d03a1e412a1035 Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/1656a082e077552eb46642d513b4a6bde9a7dd01.1601477936.git.daniel@iogearbox.net
2020-09-30bpf: Add redirect_neigh helper as redirect drop-inDaniel Borkmann
Add a redirect_neigh() helper as redirect() drop-in replacement for the xmit side. Main idea for the helper is to be very similar in semantics to the latter just that the skb gets injected into the neighboring subsystem in order to let the stack do the work it knows best anyway to populate the L2 addresses of the packet and then hand over to dev_queue_xmit() as redirect() does. This solves two bigger items: i) skbs don't need to go up to the stack on the host facing veth ingress side for traffic egressing the container to achieve the same for populating L2 which also has the huge advantage that ii) the skb->sk won't get orphaned in ip_rcv_core() when entering the IP routing layer on the host stack. Given that skb->sk neither gets orphaned when crossing the netns as per 9c4c325252c5 ("skbuff: preserve sock reference when scrubbing the skb.") the helper can then push the skbs directly to the phys device where FQ scheduler can do its work and TCP stack gets proper backpressure given we hold on to skb->sk as long as skb is still residing in queues. With the helper used in BPF data path to then push the skb to the phys device, I observed a stable/consistent TCP_STREAM improvement on veth devices for traffic going container -> host -> host -> container from ~10Gbps to ~15Gbps for a single stream in my test environment. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: David Ahern <dsahern@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Cc: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/bpf/f207de81629e1724899b73b8112e0013be782d35.1601477936.git.daniel@iogearbox.net
2020-09-30bpf: Add classid helper only based on skb->skDaniel Borkmann
Similarly to 5a52ae4e32a6 ("bpf: Allow to retrieve cgroup v1 classid from v2 hooks"), add a helper to retrieve cgroup v1 classid solely based on the skb->sk, so it can be used as key as part of BPF map lookups out of tc from host ns, in particular given the skb->sk is retained these days when crossing net ns thanks to 9c4c325252c5 ("skbuff: preserve sock reference when scrubbing the skb."). This is similar to bpf_skb_cgroup_id() which implements the same for v2. Kubernetes ecosystem is still operating on v1 however, hence net_cls needs to be used there until this can be dropped in with the v2 helper of bpf_skb_cgroup_id(). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/ed633cf27a1c620e901c5aa99ebdefb028dce600.1601477936.git.daniel@iogearbox.net
2020-09-29libbpf: Compile in PIC mode only for shared library caseAndrii Nakryiko
Libbpf compiles .o's for static and shared library modes separately, so no need to specify -fPIC for both. Keep it only for shared library mode. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200929220604.833631-3-andriin@fb.com
2020-09-29libbpf: Compile libbpf under -O2 level by default and catch extra warningsAndrii Nakryiko
For some reason compiler doesn't complain about uninitialized variable, fixed in previous patch, if libbpf is compiled without -O2 optimization level. So do compile it with -O2 and never let similar issue slip by again. -Wall is added unconditionally, so no need to specify it again. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200929220604.833631-2-andriin@fb.com
2020-09-29libbpf: Fix uninitialized variable in btf_parse_type_secAndrii Nakryiko
Fix obvious unitialized variable use that wasn't reported by compiler. libbpf Makefile changes to catch such errors are added separately. Fixes: 3289959b97ca ("libbpf: Support BTF loading and raw data output in both endianness") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200929220604.833631-1-andriin@fb.com
2020-09-29selftests/bpf: Fix endianness issues in sk_lookup/ctx_narrow_accessIlya Leoshkevich
This test makes a lot of narrow load checks while assuming little endian architecture, and therefore fails on s390. Fix by introducing LSB and LSW macros and using them to perform narrow loads. Fixes: 0ab5539f8584 ("selftests/bpf: Tests for BPF_SK_LOOKUP attach point") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200929201814.44360-1-iii@linux.ibm.com
2020-09-29bpf, selftests: Fix warning in snprintf_btf where system() call uncheckedJohn Fastabend
On my systems system() calls are marked with warn_unused_result apparently. So without error checking we get this warning, ./prog_tests/snprintf_btf.c:30:9: warning: ignoring return value of ‘system’, declared with attribute warn_unused_result[-Wunused-result] Also it seems like a good idea to check the return value anyways to ensure ping exists even if its seems unlikely. Fixes: 076a95f5aff2c ("selftests/bpf: Add bpf_snprintf_btf helper tests") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/160141006897.25201.12095049414156293265.stgit@john-Precision-5820-Tower
2020-09-29selftests: Add selftest for disallowing modify_return attachment to freplaceToke Høiland-Jørgensen
This adds a selftest that ensures that modify_return tracing programs cannot be attached to freplace programs. The security_ prefix is added to the freplace program because that would otherwise let it pass the check for modify_return. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/160138355713.48470.3811074984255709369.stgit@toke.dk
2020-09-29selftests/bpf: Adding test for arg dereference in extension traceJiri Olsa
Adding test that setup following program: SEC("classifier/test_pkt_md_access") int test_pkt_md_access(struct __sk_buff *skb) with its extension: SEC("freplace/test_pkt_md_access") int test_pkt_md_access_new(struct __sk_buff *skb) and tracing that extension with: SEC("fentry/test_pkt_md_access_new") int BPF_PROG(fentry, struct sk_buff *skb) The test verifies that the tracing program can dereference skb argument properly. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/160138355603.48470.9072073357530773228.stgit@toke.dk
2020-09-29selftests: Add test for multiple attachments of freplace programToke Høiland-Jørgensen
This adds a selftest for attaching an freplace program to multiple targets simultaneously. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/160138355497.48470.17568077161540217107.stgit@toke.dk
2020-09-29libbpf: Add support for freplace attachment in bpf_link_createToke Høiland-Jørgensen
This adds support for supplying a target btf ID for the bpf_link_create() operation, and adds a new bpf_program__attach_freplace() high-level API for attaching freplace functions with a target. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/160138355387.48470.18026176785351166890.stgit@toke.dk
2020-09-29bpf: Support attaching freplace programs to multiple attach pointsToke Høiland-Jørgensen
This enables support for attaching freplace programs to multiple attach points. It does this by amending the UAPI for bpf_link_Create with a target btf ID that can be used to supply the new attachment point along with the target program fd. The target must be compatible with the target that was supplied at program load time. The implementation reuses the checks that were factored out of check_attach_btf_id() to ensure compatibility between the BTF types of the old and new attachment. If these match, a new bpf_tracing_link will be created for the new attach target, allowing multiple attachments to co-exist simultaneously. The code could theoretically support multiple-attach of other types of tracing programs as well, but since I don't have a use case for any of those, there is no API support for doing so. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/160138355169.48470.17165680973640685368.stgit@toke.dk
2020-09-29selftests/bpf: Test BTF's handling of endiannessAndrii Nakryiko
Add selftests juggling endianness back and forth to validate BTF's handling of endianness convertions internally. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200929043046.1324350-4-andriin@fb.com
2020-09-29libbpf: Support BTF loading and raw data output in both endiannessAndrii Nakryiko
Teach BTF to recognized wrong endianness and transparently convert it internally to host endianness. Original endianness of BTF will be preserved and used during btf__get_raw_data() to convert resulting raw data to the same endianness and a source raw_data. This means that little-endian host can parse big-endian BTF with no issues, all the type data will be presented to the client application in native endianness, but when it's time for emitting BTF to persist it in a file (e.g., after BTF deduplication), original non-native endianness will be preserved and stored. It's possible to query original endianness of BTF data with new btf__endianness() API. It's also possible to override desired output endianness with btf__set_endianness(), so that if application needs to load, say, big-endian BTF and store it as little-endian BTF, it's possible to manually override this. If btf__set_endianness() was used to change endianness, btf__endianness() will reflect overridden endianness. Given there are no known use cases for supporting cross-endianness for .BTF.ext, loading .BTF.ext in non-native endianness is not supported. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200929043046.1324350-3-andriin@fb.com
2020-09-29selftests/bpf: Move and extend ASSERT_xxx() testing macrosAndrii Nakryiko
Move existing ASSERT_xxx() macros out of btf_write selftest into test_progs.h to use across all selftests. Also expand a set of macros for typical cases. Now there are the following macros: - ASSERT_EQ() -- check for equality of two integers; - ASSERT_STREQ() -- check for equality of two C strings; - ASSERT_OK() -- check for successful (zero) return result; - ASSERT_ERR() -- check for unsuccessful (non-zero) return result; - ASSERT_NULL() -- check for NULL pointer; - ASSERT_OK_PTR() -- check for a valid pointer; - ASSERT_ERR_PTR() -- check for NULL or negative error encoded in a pointer. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200929043046.1324350-2-andriin@fb.com
2020-09-29selftests: Make sure all 'skel' variables are declared staticToke Høiland-Jørgensen
If programs in prog_tests using skeletons declare the 'skel' variable as global but not static, that will lead to linker errors on the final link of the prog_tests binary due to duplicate symbols. Fix a few instances of this. Fixes: b18c1f0aa477 ("bpf: selftest: Adapt sock_fields test to use skel and global variables") Fixes: 9a856cae2217 ("bpf: selftest: Add test_btf_skc_cls_ingress") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200929123026.46751-1-toke@redhat.com
2020-09-29selftests/bpf_iter: Don't fail test due to missing __builtin_btf_type_idToke Høiland-Jørgensen
The new test for task iteration in bpf_iter checks (in do_btf_read()) if it should be skipped due to missing __builtin_btf_type_id. However, this 'skip' verdict is not propagated to the caller, so the parent test will still fail. Fix this by also skipping the rest of the parent test if the skip condition was reached. Fixes: b72091bd4ee4 ("selftests/bpf: Add test for bpf_seq_printf_btf helper") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Link: https://lore.kernel.org/bpf/20200929123004.46694-1-toke@redhat.com
2020-09-29selftests/bpf: Ensure snprintf_btf/bpf_iter tests compatibility with old ↵Alan Maguire
vmlinux.h Andrii reports that bpf selftests relying on "struct btf_ptr" and BTF_F_* values will not build as vmlinux.h for older kernels will not include "struct btf_ptr" or the BTF_F_* enum values. Undefine and redefine them to work around this. Fixes: b72091bd4ee4 ("selftests/bpf: Add test for bpf_seq_printf_btf helper") Fixes: 076a95f5aff2 ("selftests/bpf: Add bpf_snprintf_btf helper tests") Reported-by: Andrii Nakryiko <andrii.nakryiko@gmail.com> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/1601379151-21449-3-git-send-email-alan.maguire@oracle.com
2020-09-29selftests/bpf: Fix unused-result warning in snprintf_btf.cAlan Maguire
Daniel reports: + system("ping -c 1 127.0.0.1 > /dev/null"); This generates the following new warning when compiling BPF selftests: [...] EXT-OBJ [test_progs] cgroup_helpers.o EXT-OBJ [test_progs] trace_helpers.o EXT-OBJ [test_progs] network_helpers.o EXT-OBJ [test_progs] testing_helpers.o TEST-OBJ [test_progs] snprintf_btf.test.o /root/bpf-next/tools/testing/selftests/bpf/prog_tests/snprintf_btf.c: In function ‘test_snprintf_btf’: /root/bpf-next/tools/testing/selftests/bpf/prog_tests/snprintf_btf.c:30:2: warning: ignoring return value of ‘system’, declared with attribute warn_unused_result [-Wunused-result] system("ping -c 1 127.0.0.1 > /dev/null"); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [...] Fixes: 076a95f5aff2 ("selftests/bpf: Add bpf_snprintf_btf helper tests") Reported-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1601379151-21449-2-git-send-email-alan.maguire@oracle.com
2020-09-28bpf, selftests: Fix cast to smaller integer type 'int' warning in raw_tpJohn Fastabend
Fix warning in bpf selftests, progs/test_raw_tp_test_run.c:18:10: warning: cast to smaller integer type 'int' from 'struct task_struct *' [-Wpointer-to-int-cast] Change int type cast to long to fix. Discovered with gcc-9 and llvm-11+ where llvm was recent main branch. Fixes: 09d8ad16885ee ("selftests/bpf: Add raw_tp_test_run") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/160134424745.11199.13841922833336698133.stgit@john-Precision-5820-Tower
2020-09-28selftests/bpf: Test BTF writing APIsAndrii Nakryiko
Add selftests for BTF writer APIs. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200929020533.711288-4-andriin@fb.com
2020-09-28libbpf: Add btf__str_by_offset() as a more generic variant of name_by_offsetAndrii Nakryiko
BTF strings are used not just for names, they can be arbitrary strings used for CO-RE relocations, line/func infos, etc. Thus "name_by_offset" terminology is too specific and might be misleading. Instead, introduce btf__str_by_offset() API which uses generic string terminology. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200929020533.711288-3-andriin@fb.com
2020-09-28libbpf: Add BTF writing APIsAndrii Nakryiko
Add APIs for appending new BTF types at the end of BTF object. Each BTF kind has either one API of the form btf__add_<kind>(). For types that have variable amount of additional items (struct/union, enum, func_proto, datasec), additional API is provided to emit each such item. E.g., for emitting a struct, one would use the following sequence of API calls: btf__add_struct(...); btf__add_field(...); ... btf__add_field(...); Each btf__add_field() will ensure that the last BTF type is of STRUCT or UNION kind and will automatically increment that type's vlen field. All the strings are provided as C strings (const char *), not a string offset. This significantly improves usability of BTF writer APIs. All such strings will be automatically appended to string section or existing string will be re-used, if such string was already added previously. Each API attempts to do all the reasonable validations, like enforcing non-empty names for entities with required names, proper value bounds, various bit offset restrictions, etc. Type ID validation is minimal because it's possible to emit a type that refers to type that will be emitted later, so libbpf has no way to enforce such cases. User must be careful to properly emit all the necessary types and specify type IDs that will be valid in the finally generated BTF. Each of btf__add_<kind>() APIs return new type ID on success or negative value on error. APIs like btf__add_field() that emit additional items return zero on success and negative value on error. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200929020533.711288-2-andriin@fb.com
2020-09-28selftests/bpf: Add test for bpf_seq_printf_btf helperAlan Maguire
Add a test verifying iterating over tasks and displaying BTF representation of task_struct succeeds. Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1601292670-1616-9-git-send-email-alan.maguire@oracle.com
2020-09-28bpf: Add bpf_seq_printf_btf helperAlan Maguire
A helper is added to allow seq file writing of kernel data structures using vmlinux BTF. Its signature is long bpf_seq_printf_btf(struct seq_file *m, struct btf_ptr *ptr, u32 btf_ptr_size, u64 flags); Flags and struct btf_ptr definitions/use are identical to the bpf_snprintf_btf helper, and the helper returns 0 on success or a negative error value. Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1601292670-1616-8-git-send-email-alan.maguire@oracle.com
2020-09-28selftests/bpf: Fix overflow tests to reflect iter size increaseAlan Maguire
bpf iter size increase to PAGE_SIZE << 3 means overflow tests assuming page size need to be bumped also. Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1601292670-1616-7-git-send-email-alan.maguire@oracle.com
2020-09-28selftests/bpf: Add bpf_snprintf_btf helper testsAlan Maguire
Tests verifying snprintf()ing of various data structures, flags combinations using a tp_btf program. Tests are skipped if __builtin_btf_type_id is not available to retrieve BTF type ids. Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1601292670-1616-5-git-send-email-alan.maguire@oracle.com
2020-09-28bpf: Add bpf_snprintf_btf helperAlan Maguire
A helper is added to support tracing kernel type information in BPF using the BPF Type Format (BTF). Its signature is long bpf_snprintf_btf(char *str, u32 str_size, struct btf_ptr *ptr, u32 btf_ptr_size, u64 flags); struct btf_ptr * specifies - a pointer to the data to be traced - the BTF id of the type of data pointed to - a flags field is provided for future use; these flags are not to be confused with the BTF_F_* flags below that control how the btf_ptr is displayed; the flags member of the struct btf_ptr may be used to disambiguate types in kernel versus module BTF, etc; the main distinction is the flags relate to the type and information needed in identifying it; not how it is displayed. For example a BPF program with a struct sk_buff *skb could do the following: static struct btf_ptr b = { }; b.ptr = skb; b.type_id = __builtin_btf_type_id(struct sk_buff, 1); bpf_snprintf_btf(str, sizeof(str), &b, sizeof(b), 0, 0); Default output looks like this: (struct sk_buff){ .transport_header = (__u16)65535, .mac_header = (__u16)65535, .end = (sk_buff_data_t)192, .head = (unsigned char *)0x000000007524fd8b, .data = (unsigned char *)0x000000007524fd8b, .truesize = (unsigned int)768, .users = (refcount_t){ .refs = (atomic_t){ .counter = (int)1, }, }, } Flags modifying display are as follows: - BTF_F_COMPACT: no formatting around type information - BTF_F_NONAME: no struct/union member names/types - BTF_F_PTR_RAW: show raw (unobfuscated) pointer values; equivalent to %px. - BTF_F_ZERO: show zero-valued struct/union members; they are not displayed by default Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1601292670-1616-4-git-send-email-alan.maguire@oracle.com
2020-09-28libbpf: Add btf__new_empty() to create an empty BTF objectAndrii Nakryiko
Add an ability to create an empty BTF object from scratch. This is going to be used by pahole for BTF encoding. And also by selftest for convenient creation of BTF objects. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200926011357.2366158-7-andriin@fb.com
2020-09-28libbpf: Allow modification of BTF and add btf__add_str APIAndrii Nakryiko
Allow internal BTF representation to switch from default read-only mode, in which raw BTF data is a single non-modifiable block of memory with BTF header, types, and strings layed out sequentially and contiguously in memory, into a writable representation with types and strings data split out into separate memory regions, that can be dynamically expanded. Such writable internal representation is transparent to users of libbpf APIs, but allows to append new types and strings at the end of BTF, which is a typical use case when generating BTF programmatically. All the basic guarantees of BTF types and strings layout is preserved, i.e., user can get `struct btf_type *` pointer and read it directly. Such btf_type pointers might be invalidated if BTF is modified, so some care is required in such mixed read/write scenarios. Switch from read-only to writable configuration happens automatically the first time when user attempts to modify BTF by either adding a new type or new string. It is still possible to get raw BTF data, which is a single piece of memory that can be persisted in ELF section or into a file as raw BTF. Such raw data memory is also still owned by BTF and will be freed either when BTF object is freed or if another modification to BTF happens, as any modification invalidates BTF raw representation. This patch adds the first two BTF manipulation APIs: btf__add_str(), which allows to add arbitrary strings to BTF string section, and btf__find_str() which allows to find existing string offset, but not add it if it's missing. All the added strings are automatically deduplicated. This is achieved by maintaining an additional string lookup index for all unique strings. Such index is built when BTF is switched to modifiable mode. If at that time BTF strings section contained duplicate strings, they are not de-duplicated. This is done specifically to not modify the existing content of BTF (types, their string offsets, etc), which can cause confusion and is especially important property if there is struct btf_ext associated with struct btf. By following this "imperfect deduplication" process, btf_ext is kept consitent and correct. If deduplication of strings is necessary, it can be forced by doing BTF deduplication, at which point all the strings will be eagerly deduplicated and all string offsets both in struct btf and struct btf_ext will be updated. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200926011357.2366158-6-andriin@fb.com
2020-09-28libbpf: Extract generic string hashing function for reuseAndrii Nakryiko
Calculating a hash of zero-terminated string is a common need when using hashmap, so extract it for reuse. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200926011357.2366158-5-andriin@fb.com
2020-09-28libbpf: Generalize common logic for managing dynamically-sized arraysAndrii Nakryiko
Managing dynamically-sized array is a common, but not trivial functionality, which significant amount of logic and code to implement properly. So instead of re-implementing it all the time, extract it into a helper function ans reuse. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200926011357.2366158-4-andriin@fb.com
2020-09-28libbpf: Remove assumption of single contiguous memory for BTF dataAndrii Nakryiko
Refactor internals of struct btf to remove assumptions that BTF header, type data, and string data are layed out contiguously in a memory in a single memory allocation. Now we have three separate pointers pointing to the start of each respective are: header, types, strings. In the next patches, these pointers will be re-assigned to point to independently allocated memory areas, if BTF needs to be modified. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200926011357.2366158-3-andriin@fb.com