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2022-07-07selftests/bpf: Add benchmark for local_storage RCU Tasks Trace usageDave Marchevsky6-1/+416
This benchmark measures grace period latency and kthread cpu usage of RCU Tasks Trace when many processes are creating/deleting BPF local_storage. Intent here is to quantify improvement on these metrics after Paul's recent RCU Tasks patches [0]. Specifically, fork 15k tasks which call a bpf prog that creates/destroys task local_storage and sleep in a loop, resulting in many call_rcu_tasks_trace calls. To determine grace period latency, trace time elapsed between rcu_tasks_trace_pregp_step and rcu_tasks_trace_postgp; for cpu usage look at rcu_task_trace_kthread's stime in /proc/PID/stat. On my virtualized test environment (Skylake, 8 cpus) benchmark results demonstrate significant improvement: BEFORE Paul's patches: SUMMARY tasks_trace grace period latency avg 22298.551 us stddev 1302.165 us SUMMARY ticks per tasks_trace grace period avg 2.291 stddev 0.324 AFTER Paul's patches: SUMMARY tasks_trace grace period latency avg 16969.197 us stddev 2525.053 us SUMMARY ticks per tasks_trace grace period avg 1.146 stddev 0.178 Note that since these patches are not in bpf-next benchmarking was done by cherry-picking this patch onto rcu tree. [0] https://lore.kernel.org/rcu/20220620225402.GA3842369@paulmck-ThinkPad-P17-Gen-1/ Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220705190018.3239050-1-davemarchevsky@fb.com
2022-07-07libbpf, riscv: Use a0 for RC registerYixun Lan1-1/+1
According to the RISC-V calling convention register usage here [0], a0 is used as return value register, so rename it to make it consistent with the spec. [0] section 18.2, table 18.2 https://riscv.org/wp-content/uploads/2015/01/riscv-calling.pdf Fixes: 589fed479ba1 ("riscv, libbpf: Add RISC-V (RV64) support to bpf_tracing.h") Signed-off-by: Yixun Lan <dlan@gentoo.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn@kernel.org> Acked-by: Amjad OULED-AMEUR <ouledameur.amjad@gmail.com> Link: https://lore.kernel.org/bpf/20220706140204.47926-1-dlan@gentoo.org
2022-07-06libbpf: Remove unnecessary usdt_rel_ip assignmentsAndrii Nakryiko1-4/+2
Coverity detected that usdt_rel_ip is unconditionally overwritten anyways, so there is no need to unnecessarily initialize it with unused value. Clean this up. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20220705224818.4026623-4-andrii@kernel.org
2022-07-06selftests/bpf: Fix few more compiler warningsAndrii Nakryiko3-4/+4
When compiling with -O2, GCC detects few problems with selftests/bpf, so fix all of them. Two are real issues (uninitialized err and nums out-of-bounds access), but two other uninitialized variables warnings are due to GCC not being able to prove that variables are indeed initialized under conditions under which they are used. Fix all 4 cases, though. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20220705224818.4026623-3-andrii@kernel.org
2022-07-06selftests/bpf: Fix bogus uninitialized variable warningAndrii Nakryiko1-1/+1
When compiling selftests/bpf in optimized mode (-O2), GCC erroneously complains about uninitialized token variable: In file included from network_helpers.c:22: network_helpers.c: In function ‘open_netns’: test_progs.h:355:22: error: ‘token’ may be used uninitialized [-Werror=maybe-uninitialized] 355 | int ___err = libbpf_get_error(___res); \ | ^~~~~~~~~~~~~~~~~~~~~~~~ network_helpers.c:440:14: note: in expansion of macro ‘ASSERT_OK_PTR’ 440 | if (!ASSERT_OK_PTR(token, "malloc token")) | ^~~~~~~~~~~~~ In file included from /data/users/andriin/linux/tools/testing/selftests/bpf/tools/include/bpf/libbpf.h:21, from bpf_util.h:9, from network_helpers.c:20: /data/users/andriin/linux/tools/testing/selftests/bpf/tools/include/bpf/libbpf_legacy.h:113:17: note: by argument 1 of type ‘const void *’ to ‘libbpf_get_error’ declared here 113 | LIBBPF_API long libbpf_get_error(const void *ptr); | ^~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors make: *** [Makefile:522: /data/users/andriin/linux/tools/testing/selftests/bpf/network_helpers.o] Error 1 This is completely bogus becuase libbpf_get_error() doesn't dereference pointer, but the only easy way to silence this is to allocate initialized memory with calloc(). Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20220705224818.4026623-2-andrii@kernel.org
2022-07-06bpftool: Remove zlib feature test from MakefileQuentin Monnet1-9/+2
The feature test to detect the availability of zlib in bpftool's Makefile does not bring much. The library is not optional: it may or may not be required along libbfd for disassembling instructions, but in any case it is necessary to build feature.o or even libbpf, on which bpftool depends. If we remove the feature test, we lose the nicely formatted error message, but we get a compiler error about "zlib.h: No such file or directory", which is equally informative. Let's get rid of the test. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220705200456.285943-1-quentin@isovalent.com
2022-07-06libbpf: Cleanup the legacy uprobe_event on failed add/attach_event()Chuang Wang1-5/+14
A potential scenario, when an error is returned after add_uprobe_event_legacy() in perf_event_uprobe_open_legacy(), or bpf_program__attach_perf_event_opts() in bpf_program__attach_uprobe_opts() returns an error, the uprobe_event that was previously created is not cleaned. So, with this patch, when an error is returned, fix this by adding remove_uprobe_event_legacy() Signed-off-by: Chuang Wang <nashuiliang@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220629151848.65587-4-nashuiliang@gmail.com
2022-07-06libbpf: Fix wrong variable used in perf_event_uprobe_open_legacy()Chuang Wang1-1/+1
Use "type" as opposed to "err" in pr_warn() after determine_uprobe_perf_type_legacy() returns an error. Signed-off-by: Chuang Wang <nashuiliang@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220629151848.65587-3-nashuiliang@gmail.com
2022-07-06libbpf: Cleanup the legacy kprobe_event on failed add/attach_event()Chuang Wang1-4/+14
Before the 0bc11ed5ab60 commit ("kprobes: Allow kprobes coexist with livepatch"), in a scenario where livepatch and kprobe coexist on the same function entry, the creation of kprobe_event using add_kprobe_event_legacy() will be successful, at the same time as a trace event (e.g. /debugfs/tracing/events/kprobe/XXX) will exist, but perf_event_open() will return an error because both livepatch and kprobe use FTRACE_OPS_FL_IPMODIFY. As follows: 1) add a livepatch $ insmod livepatch-XXX.ko 2) add a kprobe using tracefs API (i.e. add_kprobe_event_legacy) $ echo 'p:mykprobe XXX' > /sys/kernel/debug/tracing/kprobe_events 3) enable this kprobe (i.e. sys_perf_event_open) This will return an error, -EBUSY. On Andrii Nakryiko's comment, few error paths in bpf_program__attach_kprobe_opts() that should need to call remove_kprobe_event_legacy(). With this patch, whenever an error is returned after add_kprobe_event_legacy() or bpf_program__attach_perf_event_opts(), this ensures that the created kprobe_event is cleaned. Signed-off-by: Chuang Wang <nashuiliang@gmail.com> Signed-off-by: Jingren Zhou <zhoujingren@didiglobal.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220629151848.65587-2-nashuiliang@gmail.com
2022-07-06selftests/bpf: Add type match test against kernel's task_structDaniel Müller3-0/+21
This change extends the existing core_reloc/kernel test to include a type match check of a local task_struct against the kernel's definition -- which we assume to succeed. Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220628160127.607834-11-deso@posteo.net
2022-07-06selftests/bpf: Add nested type to type based testsDaniel Müller3-20/+58
This change extends the type based tests with another struct type (in addition to a_struct) to check relocations against: a_complex_struct. This type is nested more deeply to provide additional coverage of certain paths in the type match logic. Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220628160127.607834-10-deso@posteo.net
2022-07-06selftests/bpf: Add test checking more characteristicsDaniel Müller3-0/+91
This change adds another type-based self-test that specifically aims to test some more characteristics of the TYPE_MATCH logic. Specifically, it covers a few more potential differences between types, such as different orders, enum variant values, and integer signedness. Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220628160127.607834-9-deso@posteo.net
2022-07-06selftests/bpf: Add type-match checks to type-based testsDaniel Müller3-4/+73
Now that we have type-match logic in both libbpf and the kernel, this change adjusts the existing BPF self tests to check this functionality. Specifically, we extend the existing type-based tests to check the previously introduced bpf_core_type_matches macro. Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220628160127.607834-8-deso@posteo.net
2022-07-06libbpf: add bpf_core_type_matches() helper macroAndrii Nakryiko1-0/+10
This patch finalizes support for the proposed type match relation in libbpf by adding bpf_core_type_matches() macro which emits TYPE_MATCH relocation. Clang support for this relocation was added in [0]. [0] https://reviews.llvm.org/D126838 Signed-off-by: Daniel Müller <deso@posteo.net>¬ Signed-off-by: Andrii Nakryiko <andrii@kernel.org>¬ Link: https://lore.kernel.org/bpf/20220628160127.607834-7-deso@posteo.net¬
2022-07-06bpf, libbpf: Add type match supportDaniel Müller4-4/+294
This patch adds support for the proposed type match relation to relo_core where it is shared between userspace and kernel. It plumbs through both kernel-side and libbpf-side support. The matching relation is defined as follows (copy from source): - modifiers and typedefs are stripped (and, hence, effectively ignored) - generally speaking types need to be of same kind (struct vs. struct, union vs. union, etc.) - exceptions are struct/union behind a pointer which could also match a forward declaration of a struct or union, respectively, and enum vs. enum64 (see below) Then, depending on type: - integers: - match if size and signedness match - arrays & pointers: - target types are recursively matched - structs & unions: - local members need to exist in target with the same name - for each member we recursively check match unless it is already behind a pointer, in which case we only check matching names and compatible kind - enums: - local variants have to have a match in target by symbolic name (but not numeric value) - size has to match (but enum may match enum64 and vice versa) - function pointers: - number and position of arguments in local type has to match target - for each argument and the return value we recursively check match Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220628160127.607834-5-deso@posteo.net
2022-07-06bpftool: Honor BPF_CORE_TYPE_MATCHES relocationDaniel Müller1-0/+108
bpftool needs to know about the newly introduced BPF_CORE_TYPE_MATCHES relocation for its 'gen min_core_btf' command to work properly in the present of this relocation. Specifically, we need to make sure to mark types and fields so that they are present in the minimized BTF for "type match" checks to work out. However, contrary to the existing btfgen_record_field_relo, we need to rely on the BTF -- and not the spec -- to find fields. With this change we handle this new variant correctly. The functionality will be tested with follow on changes to BPF selftests, which already run against a minimized BTF created with bpftool. Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20220628160127.607834-3-deso@posteo.net
2022-07-06bpf: Introduce TYPE_MATCH related constants/macrosDaniel Müller3-0/+3
In order to provide type match support we require a new type of relocation which, in turn, requires toolchain support. Recent LLVM/Clang versions support a new value for the last argument to the __builtin_preserve_type_info builtin, for example. With this change we introduce the necessary constants into relevant header files, mirroring what the compiler may support. Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220628160127.607834-2-deso@posteo.net
2022-07-05bpf, samples: Remove AF_XDP samplesMagnus Karlsson7-3348/+0
Remove the AF_XDP samples from samples/bpf/ as they are dependent on the AF_XDP support in libbpf. This support has now been removed in the 1.0 release, so these samples cannot be compiled anymore. Please start to use libxdp instead. It is backwards compatible with the AF_XDP support that was offered in libbpf. New samples can be found in the various xdp-project repositories connected to libxdp and by googling. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/20220630093717.8664-1-magnus.karlsson@gmail.com
2022-07-05bpftool: Rename "bpftool feature list" into "... feature list_builtins"Quentin Monnet3-11/+11
To make it more explicit that the features listed with "bpftool feature list" are known to bpftool, but not necessary available on the system (as opposed to the probed features), rename the "feature list" command into "feature list_builtins". Note that "bpftool feature list" still works as before given that we recognise arguments from their prefixes; but the real name of the subcommand, in particular as displayed in the man page or the interactive help, will now include "_builtins". Since we update the bash completion accordingly, let's also take this chance to redirect error output to /dev/null in the completion script, to avoid displaying unexpected error messages when users attempt to tab-complete. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20220701093805.16920-1-quentin@isovalent.com
2022-07-05bpf: Omit superfluous address family check in __bpf_skc_lookupTobias Klauser1-3/+2
family is only set to either AF_INET or AF_INET6 based on len. In all other cases we return early. Thus the check against AF_UNSPEC can be omitted. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220630082618.15649-1-tklauser@distanz.ch
2022-07-01selftests/bpf: Skip lsm_cgroup when we don't have trampolinesStanislav Fomichev1-0/+8
With arch_prepare_bpf_trampoline removed on x86: [...] #98/1 lsm_cgroup/functional:SKIP #98 lsm_cgroup:SKIP Summary: 1/0 PASSED, 1 SKIPPED, 0 FAILED Fixes: dca85aac8895 ("selftests/bpf: lsm_cgroup functional test") Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Hao Luo <haoluo@google.com> Link: https://lore.kernel.org/bpf/20220630224203.512815-1-sdf@google.com
2022-06-30bpftool: Show also the name of type BPF_OBJ_LINKYafang Shao1-0/+1
For example, /sys/fs/bpf/maps.debug is a BPF link. When you run `bpftool map show` to show it: Before: $ bpftool map show pinned /sys/fs/bpf/maps.debug Error: incorrect object type: unknown After: $ bpftool map show pinned /sys/fs/bpf/maps.debug Error: incorrect object type: link Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20220629154832.56986-5-laoar.shao@gmail.com
2022-06-30selftests/xsk: Destroy BPF resources only when ctx refcount drops to 0Maciej Fijalkowski1-5/+4
Currently, xsk_socket__delete frees BPF resources regardless of ctx refcount. Xdpxceiver has a test to verify whether underlying BPF resources would not be wiped out after closing XSK socket that was bound to interface with other active sockets. From library's xsk part perspective it also means that the internal xsk context is shared and its refcount is bumped accordingly. After a switch to loading XDP prog based on previously opened XSK socket, mentioned xdpxceiver test fails with: not ok 16 [xdpxceiver.c:swap_xsk_resources:1334]: ERROR: 9/"Bad file descriptor which means that in swap_xsk_resources(), xsk_socket__delete() released xskmap which in turn caused a failure of xsk_socket__update_xskmap(). To fix this, when deleting socket, decrement ctx refcount before releasing BPF resources and do so only when refcount dropped to 0 which means there are no more active sockets for this ctx so BPF resources can be freed safely. Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices") Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20220629143458.934337-5-maciej.fijalkowski@intel.com
2022-06-30selftests/xsk: Verify correctness of XDP prog attach pointMaciej Fijalkowski1-0/+17
To prevent the case we had previously where for TEST_MODE_SKB, XDP prog was attached in native mode, call bpf_xdp_query() after loading prog and make sure that attach_mode is as expected. Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20220629143458.934337-4-maciej.fijalkowski@intel.com
2022-06-30selftests/xsk: Introduce XDP prog load based on existing AF_XDP socketMaciej Fijalkowski3-1/+7
Currently, xsk_setup_xdp_prog() uses anonymous xsk_socket struct which means that during xsk_create_bpf_link() call, xsk->config.xdp_flags is always 0. This in turn means that from xdpxceiver it is impossible to use xdpgeneric attachment, so since commit 3b22523bca02 ("selftests, xsk: Fix bpf_res cleanup test") we were not testing SKB mode at all. To fix this, introduce a function, called xsk_setup_xdp_prog_xsk(), that will load XDP prog based on the existing xsk_socket, so that xsk context's refcount is correctly bumped and flags from application side are respected. Use this from xdpxceiver side so we get coverage of generic and native XDP program attach points. Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20220629143458.934337-3-maciej.fijalkowski@intel.com
2022-06-30selftests/xsk: Avoid bpf_link probe for existing xskMaciej Fijalkowski1-1/+1
Currently bpf_link probe is done for each call of xsk_socket__create(). For cases where xsk context was previously created and current socket creation uses it, has_bpf_link will be overwritten, where it has already been initialized. Optimize this by moving the query to the xsk_create_ctx() so that when xsk_get_ctx() finds a ctx then no further bpf_link probes are needed. Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20220629143458.934337-2-maciej.fijalkowski@intel.com
2022-06-30bpftool: Use feature list in bash completionQuentin Monnet2-34/+7
Now that bpftool is able to produce a list of known program, map, attach types, let's use as much of this as we can in the bash completion file, so that we don't have to expand the list each time a new type is added to the kernel. Also update the relevant test script to remove some checks that are no longer needed. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Müller <deso@posteo.net> Link: https://lore.kernel.org/bpf/20220629203637.138944-3-quentin@isovalent.com
2022-06-30bpftool: Add feature list (prog/map/link/attach types, helpers)Quentin Monnet3-1/+73
Add a "bpftool feature list" subcommand to list BPF "features". Contrarily to "bpftool feature probe", this is not about the features available on the system. Instead, it lists all features known to bpftool from compilation time; in other words, all program, map, attach, link types known to the libbpf version in use, and all helpers found in the UAPI BPF header. The first use case for this feature is bash completion: running the command provides a list of types that can be used to produce the list of candidate map types, for example. Now that bpftool uses "standard" names provided by libbpf for the program, map, link, and attach types, having the ability to list these types and helpers could also be useful in scripts to loop over existing items. Sample output: # bpftool feature list prog_types | grep -vw unspec | head -n 6 socket_filter kprobe sched_cls sched_act tracepoint xdp # bpftool -p feature list map_types | jq '.[1]' "hash" # bpftool feature list attach_types | grep '^cgroup_' cgroup_inet_ingress cgroup_inet_egress [...] cgroup_inet_sock_release # bpftool feature list helpers | grep -vw bpf_unspec | wc -l 207 The "unspec" types and helpers are not filtered out by bpftool, so as to remain closer to the enums, and to preserve the indices in the JSON arrays (e.g. "hash" at index 1 == BPF_MAP_TYPE_HASH in map types list). Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Müller <deso@posteo.net> Link: https://lore.kernel.org/bpf/20220629203637.138944-2-quentin@isovalent.com
2022-06-30bpftool: Remove attach_type_name forward declarationTobias Klauser1-2/+0
The attach_type_name definition was removed in commit 1ba5ad36e00f ("bpftool: Use libbpf_bpf_attach_type_str"). Remove its forward declaration in main.h as well. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20220630093638.25916-1-tklauser@distanz.ch
2022-06-29bpftool: Probe for memcg-based accounting before bumping rlimitQuentin Monnet1-3/+68
Bpftool used to bump the memlock rlimit to make sure to be able to load BPF objects. After the kernel has switched to memcg-based memory accounting [0] in 5.11, bpftool has relied on libbpf to probe the system for memcg-based accounting support and for raising the rlimit if necessary [1]. But this was later reverted, because the probe would sometimes fail, resulting in bpftool not being able to load all required objects [2]. Here we add a more efficient probe, in bpftool itself. We first lower the rlimit to 0, then we attempt to load a BPF object (and finally reset the rlimit): if the load succeeds, then memcg-based memory accounting is supported. This approach was earlier proposed for the probe in libbpf itself [3], but given that the library may be used in multithreaded applications, the probe could have undesirable consequences if one thread attempts to lock kernel memory while memlock rlimit is at 0. Since bpftool is single-threaded and the rlimit is process-based, this is fine to do in bpftool itself. This probe was inspired by the similar one from the cilium/ebpf Go library [4]. [0] commit 97306be45fbe ("Merge branch 'switch to memcg-based memory accounting'") [1] commit a777e18f1bcd ("bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK") [2] commit 6b4384ff1088 ("Revert "bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK"") [3] https://lore.kernel.org/bpf/20220609143614.97837-1-quentin@isovalent.com/t/#u [4] https://github.com/cilium/ebpf/blob/v0.9.0/rlimit/rlimit.go#L39 Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Stanislav Fomichev <sdf@google.com> Acked-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/bpf/20220629111351.47699-1-quentin@isovalent.com
2022-06-29selftests/bpf: lsm_cgroup functional testStanislav Fomichev3-0/+474
Functional test that exercises the following: 1. apply default sk_priority policy 2. permit TX-only AF_PACKET socket 3. cgroup attach/detach/replace 4. reusing trampoline shim Signed-off-by: Stanislav Fomichev <sdf@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/r/20220628174314.1216643-12-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-29bpftool: implement cgroup tree for BPF_LSM_CGROUPStanislav Fomichev1-22/+87
$ bpftool --nomount prog loadall $KDIR/tools/testing/selftests/bpf/lsm_cgroup.o /sys/fs/bpf/x $ bpftool cgroup attach /sys/fs/cgroup lsm_cgroup pinned /sys/fs/bpf/x/socket_alloc $ bpftool cgroup attach /sys/fs/cgroup lsm_cgroup pinned /sys/fs/bpf/x/socket_bind $ bpftool cgroup attach /sys/fs/cgroup lsm_cgroup pinned /sys/fs/bpf/x/socket_clone $ bpftool cgroup attach /sys/fs/cgroup lsm_cgroup pinned /sys/fs/bpf/x/socket_post_create $ bpftool cgroup tree CgroupPath ID AttachType AttachFlags Name /sys/fs/cgroup 6 lsm_cgroup socket_post_create bpf_lsm_socket_post_create 8 lsm_cgroup socket_bind bpf_lsm_socket_bind 10 lsm_cgroup socket_alloc bpf_lsm_sk_alloc_security 11 lsm_cgroup socket_clone bpf_lsm_inet_csk_clone $ bpftool cgroup detach /sys/fs/cgroup lsm_cgroup pinned /sys/fs/bpf/x/socket_post_create $ bpftool cgroup tree CgroupPath ID AttachType AttachFlags Name /sys/fs/cgroup 8 lsm_cgroup socket_bind bpf_lsm_socket_bind 10 lsm_cgroup socket_alloc bpf_lsm_sk_alloc_security 11 lsm_cgroup socket_clone bpf_lsm_inet_csk_clone Reviewed-by: Quentin Monnet <quentin@isovalent.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20220628174314.1216643-11-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-29libbpf: implement bpf_prog_query_optsStanislav Fomichev3-7/+47
Implement bpf_prog_query_opts as a more expendable version of bpf_prog_query. Expose new prog_attach_flags and attach_btf_func_id as well: * prog_attach_flags is a per-program attach_type; relevant only for lsm cgroup program which might have different attach_flags per attach_btf_id * attach_btf_func_id is a new field expose for prog_query which specifies real btf function id for lsm cgroup attachments Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20220628174314.1216643-10-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-29libbpf: add lsm_cgoup_sock typeStanislav Fomichev1-0/+3
lsm_cgroup/ is the prefix for BPF_LSM_CGROUP. Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20220628174314.1216643-9-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-29tools/bpf: Sync btf_ids.h to toolsStanislav Fomichev3-8/+32
Has been slowly getting out of sync, let's update it. resolve_btfids usage has been updated to match the header changes. Also bring new parts of tools/include/uapi/linux/bpf.h. Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20220628174314.1216643-8-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-29bpf: expose bpf_{g,s}etsockopt to lsm cgroupStanislav Fomichev3-7/+93
I don't see how to make it nice without introducing btf id lists for the hooks where these helpers are allowed. Some LSM hooks work on the locked sockets, some are triggering early and don't grab any locks, so have two lists for now: 1. LSM hooks which trigger under socket lock - minority of the hooks, but ideal case for us, we can expose existing BTF-based helpers 2. LSM hooks which trigger without socket lock, but they trigger early in the socket creation path where it should be safe to do setsockopt without any locks 3. The rest are prohibited. I'm thinking that this use-case might be a good gateway to sleeping lsm cgroup hooks in the future. We can either expose lock/unlock operations (and add tracking to the verifier) or have another set of bpf_setsockopt wrapper that grab the locks and might sleep. Reviewed-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20220628174314.1216643-7-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-29bpf: implement BPF_PROG_QUERY for BPF_LSM_CGROUPStanislav Fomichev3-32/+74
We have two options: 1. Treat all BPF_LSM_CGROUP the same, regardless of attach_btf_id 2. Treat BPF_LSM_CGROUP+attach_btf_id as a separate hook point I was doing (2) in the original patch, but switching to (1) here: * bpf_prog_query returns all attached BPF_LSM_CGROUP programs regardless of attach_btf_id * attach_btf_id is exported via bpf_prog_info Reviewed-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20220628174314.1216643-6-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-29bpf: minimize number of allocated lsm slots per programStanislav Fomichev8-24/+64
Previous patch adds 1:1 mapping between all 211 LSM hooks and bpf_cgroup program array. Instead of reserving a slot per possible hook, reserve 10 slots per cgroup for lsm programs. Those slots are dynamically allocated on demand and reclaimed. struct cgroup_bpf { struct bpf_prog_array * effective[33]; /* 0 264 */ /* --- cacheline 4 boundary (256 bytes) was 8 bytes ago --- */ struct hlist_head progs[33]; /* 264 264 */ /* --- cacheline 8 boundary (512 bytes) was 16 bytes ago --- */ u8 flags[33]; /* 528 33 */ /* XXX 7 bytes hole, try to pack */ struct list_head storages; /* 568 16 */ /* --- cacheline 9 boundary (576 bytes) was 8 bytes ago --- */ struct bpf_prog_array * inactive; /* 584 8 */ struct percpu_ref refcnt; /* 592 16 */ struct work_struct release_work; /* 608 72 */ /* size: 680, cachelines: 11, members: 7 */ /* sum members: 673, holes: 1, sum holes: 7 */ /* last cacheline: 40 bytes */ }; Reviewed-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20220628174314.1216643-5-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-29bpf: per-cgroup lsm flavorStanislav Fomichev15-20/+498
Allow attaching to lsm hooks in the cgroup context. Attaching to per-cgroup LSM works exactly like attaching to other per-cgroup hooks. New BPF_LSM_CGROUP is added to trigger new mode; the actual lsm hook we attach to is signaled via existing attach_btf_id. For the hooks that have 'struct socket' or 'struct sock' as its first argument, we use the cgroup associated with that socket. For the rest, we use 'current' cgroup (this is all on default hierarchy == v2 only). Note that for some hooks that work on 'struct sock' we still take the cgroup from 'current' because some of them work on the socket that hasn't been properly initialized yet. Behind the scenes, we allocate a shim program that is attached to the trampoline and runs cgroup effective BPF programs array. This shim has some rudimentary ref counting and can be shared between several programs attaching to the same lsm hook from different cgroups. Note that this patch bloats cgroup size because we add 211 cgroup_bpf_attach_type(s) for simplicity sake. This will be addressed in the subsequent patch. Also note that we only add non-sleepable flavor for now. To enable sleepable use-cases, bpf_prog_run_array_cg has to grab trace rcu, shim programs have to be freed via trace rcu, cgroup_bpf.effective should be also trace-rcu-managed + maybe some other changes that I'm not aware of. Reviewed-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20220628174314.1216643-4-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-29bpf: convert cgroup_bpf.progs to hlistStanislav Fomichev3-35/+47
This lets us reclaim some space to be used by new cgroup lsm slots. Before: struct cgroup_bpf { struct bpf_prog_array * effective[23]; /* 0 184 */ /* --- cacheline 2 boundary (128 bytes) was 56 bytes ago --- */ struct list_head progs[23]; /* 184 368 */ /* --- cacheline 8 boundary (512 bytes) was 40 bytes ago --- */ u32 flags[23]; /* 552 92 */ /* XXX 4 bytes hole, try to pack */ /* --- cacheline 10 boundary (640 bytes) was 8 bytes ago --- */ struct list_head storages; /* 648 16 */ struct bpf_prog_array * inactive; /* 664 8 */ struct percpu_ref refcnt; /* 672 16 */ struct work_struct release_work; /* 688 32 */ /* size: 720, cachelines: 12, members: 7 */ /* sum members: 716, holes: 1, sum holes: 4 */ /* last cacheline: 16 bytes */ }; After: struct cgroup_bpf { struct bpf_prog_array * effective[23]; /* 0 184 */ /* --- cacheline 2 boundary (128 bytes) was 56 bytes ago --- */ struct hlist_head progs[23]; /* 184 184 */ /* --- cacheline 5 boundary (320 bytes) was 48 bytes ago --- */ u8 flags[23]; /* 368 23 */ /* XXX 1 byte hole, try to pack */ /* --- cacheline 6 boundary (384 bytes) was 8 bytes ago --- */ struct list_head storages; /* 392 16 */ struct bpf_prog_array * inactive; /* 408 8 */ struct percpu_ref refcnt; /* 416 16 */ struct work_struct release_work; /* 432 72 */ /* size: 504, cachelines: 8, members: 7 */ /* sum members: 503, holes: 1, sum holes: 1 */ /* last cacheline: 56 bytes */ }; Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Reviewed-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20220628174314.1216643-3-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-29bpf: add bpf_func_t and trampoline helpersStanislav Fomichev2-36/+38
I'll be adding lsm cgroup specific helpers that grab trampoline mutex. No functional changes. Reviewed-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20220628174314.1216643-2-sdf@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: fix up few libbpf.map problemsAndrii Nakryiko2-3/+4
Seems like we missed to add 2 APIs to libbpf.map and another API was misspelled. Fix it in libbpf.map. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-16-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: enforce strict libbpf 1.0 behaviorsAndrii Nakryiko5-261/+37
Remove support for legacy features and behaviors that previously had to be disabled by calling libbpf_set_strict_mode(): - legacy BPF map definitions are not supported now; - RLIMIT_MEMLOCK auto-setting, if necessary, is always on (but see libbpf_set_memlock_rlim()); - program name is used for program pinning (instead of section name); - cleaned up error returning logic; - entry BPF programs should have SEC() always. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-15-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28selftests/bpf: remove last tests with legacy BPF map definitionsAndrii Nakryiko4-79/+0
Libbpf 1.0 stops support legacy-style BPF map definitions. Selftests has been migrated away from using legacy BPF map definitions except for two selftests, to make sure that legacy functionality still worked in pre-1.0 libbpf. Now it's time to let those tests go as libbpf 1.0 is imminent. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-14-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: clean up SEC() handlingAndrii Nakryiko1-72/+47
Get rid of sloppy prefix logic and remove deprecated xdp_{devmap,cpumap} sections. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-13-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: remove internal multi-instance prog supportAndrii Nakryiko1-283/+34
Clean up internals that had to deal with the possibility of multi-instance bpf_programs. Libbpf 1.0 doesn't support this, so all this is not necessary now and can be simplified. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-12-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: cleanup LIBBPF_DEPRECATED_SINCE supporting macros for v0.xAndrii Nakryiko1-13/+3
Keep the LIBBPF_DEPRECATED_SINCE macro "framework" for future deprecations, but clean up 0.x related helper macros. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-11-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: remove multi-instance and custom private data APIsAndrii Nakryiko3-212/+10
Remove all the public APIs that are related to creating multi-instance bpf_programs through custom preprocessing callback and generally working with them. Also remove all the bpf_{object,map,program}__[set_]priv() APIs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-10-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: remove most other deprecated high-level APIsAndrii Nakryiko3-421/+26
Remove a bunch of high-level bpf_object/bpf_map/bpf_program related APIs. All the APIs related to private per-object/map/prog state, program preprocessing callback, and generally everything multi-instance related is removed in a separate patch. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-9-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-28libbpf: remove prog_info_linear APIsAndrii Nakryiko3-317/+0
Remove prog_info_linear-related APIs previously used by perf. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-8-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>