- 07 10月, 2021 2 次提交
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由 Hengqi Chen 提交于
Deprecate bpf_{map,program}__{prev,next} APIs. Replace them with a new set of APIs named bpf_object__{prev,next}_{program,map} which follow the libbpf API naming convention ([0]). No functionality changes. [0] Closes: https://github.com/libbpf/libbpf/issues/296Signed-off-by: NHengqi Chen <hengqi.chen@gmail.com> Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Acked-by: NSong Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20211003165844.4054931-2-hengqi.chen@gmail.com
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由 Hengqi Chen 提交于
BPF objects are not reloadable after unload. Users are expected to use bpf_object__close() to unload and free up resources in one operation. No need to expose bpf_object__unload() as a public API, deprecate it ([0]). Add bpf_object__unload() as an alias to internal bpf_object_unload() and replace all bpf_object__unload() uses to avoid compilation errors. [0] Closes: https://github.com/libbpf/libbpf/issues/290Signed-off-by: NHengqi Chen <hengqi.chen@gmail.com> Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Acked-by: NSong Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20211002161000.3854559-1-hengqi.chen@gmail.com
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- 22 9月, 2021 1 次提交
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由 Andrii Nakryiko 提交于
Refactor legacy kprobe handling code to follow the same logic as uprobe legacy logic added in the next patchs: - add append_to_file() helper that makes it simpler to work with tracefs file-based interface for creating and deleting probes; - move out probe/event name generation outside of the code that adds/removes it, which simplifies bookkeeping significantly; - change the probe name format to start with "libbpf_" prefix and include offset within kernel function; - switch 'unsigned long' to 'size_t' for specifying kprobe offsets, which is consistent with how uprobes define that, simplifies printf()-ing internally, and also avoids unnecessary complications on architectures where sizeof(long) != sizeof(void *). This patch also implicitly fixes the problem with invalid open() error handling present in poke_kprobe_events(), which (the function) this patch removes. Fixes: ca304b40 ("libbpf: Introduce legacy kprobe events support") Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210921210036.1545557-4-andrii@kernel.org
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- 21 9月, 2021 1 次提交
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由 Grant Seltzer 提交于
This adds comments above functions in libbpf.h which document their uses. These comments are of a format that doxygen and sphinx can pick up and render. These are rendered by libbpf.readthedocs.org These doc comments are for: - bpf_object__find_map_by_name() - bpf_map__fd() - bpf_map__is_internal() - libbpf_get_error() - libbpf_num_possible_cpus() Signed-off-by: NGrant Seltzer <grantseltzer@gmail.com> Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210918031457.36204-1-grantseltzer@gmail.com
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- 18 9月, 2021 3 次提交
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由 Andrii Nakryiko 提交于
Attach APIs shouldn't need to modify bpf_program/bpf_map structs, so change all struct bpf_program and struct bpf_map pointers to const pointers. This is completely backwards compatible with no functional change. Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NYonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210916015836.1248906-8-andrii@kernel.org
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由 Andrii Nakryiko 提交于
bpf_object_open_opts.attach_prog_fd makes a pretty strong assumption that bpf_object contains either only single freplace BPF program or all of BPF programs in BPF object are freplaces intended to replace different subprograms of the same target BPF program. This seems both a bit confusing, too assuming, and limiting. We've had bpf_program__set_attach_target() API which allows more fine-grained control over this, on a per-program level. As such, mark open_opts.attach_prog_fd as deprecated starting from v0.7, so that we have one more universal way of setting freplace targets. With previous change to allow NULL attach_func_name argument, and especially combined with BPF skeleton, arguable bpf_program__set_attach_target() is a more convenient and explicit API as well. Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NYonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210916015836.1248906-7-andrii@kernel.org
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由 Andrii Nakryiko 提交于
It's relevant and hasn't been doing anything for a long while now. Deprecated it. Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NYonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210916015836.1248906-4-andrii@kernel.org
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- 08 9月, 2021 1 次提交
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由 Matt Smith 提交于
This change was necessary to enforce the implied contract that bpf_object_skeleton->data should not be mutated. The data will be cast to `void *` during assignment to handle the case where a user is compiling with older libbpf headers to avoid a compiler warning of `const void *` data being cast to `void *` Signed-off-by: NMatt Smith <alastorze@fb.com> Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210901194439.3853238-2-alastorze@fb.com
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- 17 8月, 2021 2 次提交
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由 Andrii Nakryiko 提交于
When attaching to uprobes through perf subsystem, it's possible to specify offset of a so-called USDT semaphore, which is just a reference counted u16, used by kernel to keep track of how many tracers are attached to a given location. Support for this feature was added in [0], so just wire this through uprobe_opts. This is important to enable implementing USDT attachment and tracing through libbpf's bpf_program__attach_uprobe_opts() API. [0] a6ca88b2 ("trace_uprobe: support reference counter in fd-based uprobe") Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210815070609.987780-16-andrii@kernel.org
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由 Andrii Nakryiko 提交于
Wire through bpf_cookie for all attach APIs that use perf_event_open under the hood: - for kprobes, extend existing bpf_kprobe_opts with bpf_cookie field; - for perf_event, uprobe, and tracepoint APIs, add their _opts variants and pass bpf_cookie through opts. For kernel that don't support BPF_LINK_CREATE for perf_events, and thus bpf_cookie is not supported either, return error and log warning for user. Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210815070609.987780-12-andrii@kernel.org
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- 24 7月, 2021 1 次提交
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由 Evgeniy Litvinenko 提交于
Add bpf_map__pin_path, so that the inconsistently named bpf_map__get_pin_path can be deprecated later. This is part of the effort towards libbpf v1.0: https://github.com/libbpf/libbpf/issues/307 Also, add a selftest for the new function. Signed-off-by: NEvgeniy Litvinenko <evgeniyl@fb.com> Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210723221511.803683-1-evgeniyl@fb.com
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- 23 7月, 2021 1 次提交
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由 Jiri Olsa 提交于
Export bpf_program__attach_kprobe_opts as a public API. Rename bpf_program_attach_kprobe_opts to bpf_kprobe_opts and turn it into OPTS struct. Suggested-by: NAndrii Nakryiko <andrii@kernel.org> Signed-off-by: NJiri Olsa <jolsa@kernel.org> Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Reviewed-by: NAlan Maguire <alan.maguire@oracle.com> Tested-by: NAlan Maguire <alan.maguire@oracle.com> Link: https://lore.kernel.org/bpf/20210721215810.889975-4-jolsa@kernel.org
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- 17 7月, 2021 1 次提交
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由 Shuyi Cheng 提交于
btf_custom_path allows developers to load custom BTF which libbpf will subsequently use for CO-RE relocation instead of vmlinux BTF. Having btf_custom_path in bpf_object_open_opts one can directly use the skeleton's <objname>_bpf__open_opts() API to pass in the btf_custom_path parameter, as opposed to using bpf_object__load_xattr() which is slated to be deprecated ([0]). This work continues previous work started by another developer ([1]). [0] https://lore.kernel.org/bpf/CAEf4BzbJZLjNoiK8_VfeVg_Vrg=9iYFv+po-38SMe=UzwDKJ=Q@mail.gmail.com/#t [1] https://yhbt.net/lore/all/CAEf4Bzbgw49w2PtowsrzKQNcxD4fZRE6AKByX-5-dMo-+oWHHA@mail.gmail.com/Signed-off-by: NShuyi Cheng <chengshuyi@linux.alibaba.com> Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1626180159-112996-2-git-send-email-chengshuyi@linux.alibaba.com
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- 26 5月, 2021 1 次提交
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由 Andrii Nakryiko 提交于
Add libbpf_set_strict_mode() API that allows application to simulate libbpf 1.0 breaking changes before libbpf 1.0 is released. This will help users migrate gradually and with confidence. For now only ALL or NONE options are available, subsequent patches will add more flags. This patch is preliminary for selftests/bpf changes. Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NJohn Fastabend <john.fastabend@gmail.com> Acked-by: NToke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20210525035935.1461796-2-andrii@kernel.org
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- 19 5月, 2021 2 次提交
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由 Alexei Starovoitov 提交于
Introduce bpf_map__initial_value() to read initial contents of mmaped data/rodata/bss maps. Note that bpf_map__set_initial_value() doesn't allow modifying kconfig map while bpf_map__initial_value() allows reading its values. Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAndrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210514003623.28033-17-alexei.starovoitov@gmail.com
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由 Alexei Starovoitov 提交于
The BPF program loading process performed by libbpf is quite complex and consists of the following steps: "open" phase: - parse elf file and remember relocations, sections - collect externs and ksyms including their btf_ids in prog's BTF - patch BTF datasec (since llvm couldn't do it) - init maps (old style map_def, BTF based, global data map, kconfig map) - collect relocations against progs and maps "load" phase: - probe kernel features - load vmlinux BTF - resolve externs (kconfig and ksym) - load program BTF - init struct_ops - create maps - apply CO-RE relocations - patch ld_imm64 insns with src_reg=PSEUDO_MAP, PSEUDO_MAP_VALUE, PSEUDO_BTF_ID - reposition subprograms and adjust call insns - sanitize and load progs During this process libbpf does sys_bpf() calls to load BTF, create maps, populate maps and finally load programs. Instead of actually doing the syscalls generate a trace of what libbpf would have done and represent it as the "loader program". The "loader program" consists of single map with: - union bpf_attr(s) - BTF bytes - map value bytes - insns bytes and single bpf program that passes bpf_attr(s) and data into bpf_sys_bpf() helper. Executing such "loader program" via bpf_prog_test_run() command will replay the sequence of syscalls that libbpf would have done which will result the same maps created and programs loaded as specified in the elf file. The "loader program" removes libelf and majority of libbpf dependency from program loading process. kconfig, typeless ksym, struct_ops and CO-RE are not supported yet. The order of relocate_data and relocate_calls had to change, so that bpf_gen__prog_load() can see all relocations for a given program with correct insn_idx-es. Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAndrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210514003623.28033-15-alexei.starovoitov@gmail.com
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- 17 5月, 2021 1 次提交
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由 Kumar Kartikeya Dwivedi 提交于
This adds functions that wrap the netlink API used for adding, manipulating, and removing traffic control filters. The API summary: A bpf_tc_hook represents a location where a TC-BPF filter can be attached. This means that creating a hook leads to creation of the backing qdisc, while destruction either removes all filters attached to a hook, or destroys qdisc if requested explicitly (as discussed below). The TC-BPF API functions operate on this bpf_tc_hook to attach, replace, query, and detach tc filters. All functions return 0 on success, and a negative error code on failure. bpf_tc_hook_create - Create a hook Parameters: @hook - Cannot be NULL, ifindex > 0, attach_point must be set to proper enum constant. Note that parent must be unset when attach_point is one of BPF_TC_INGRESS or BPF_TC_EGRESS. Note that as an exception BPF_TC_INGRESS|BPF_TC_EGRESS is also a valid value for attach_point. Returns -EOPNOTSUPP when hook has attach_point as BPF_TC_CUSTOM. bpf_tc_hook_destroy - Destroy a hook Parameters: @hook - Cannot be NULL. The behaviour depends on value of attach_point. If BPF_TC_INGRESS, all filters attached to the ingress hook will be detached. If BPF_TC_EGRESS, all filters attached to the egress hook will be detached. If BPF_TC_INGRESS|BPF_TC_EGRESS, the clsact qdisc will be deleted, also detaching all filters. As before, parent must be unset for these attach_points, and set for BPF_TC_CUSTOM. It is advised that if the qdisc is operated on by many programs, then the program at least check that there are no other existing filters before deleting the clsact qdisc. An example is shown below: DECLARE_LIBBPF_OPTS(bpf_tc_hook, .ifindex = if_nametoindex("lo"), .attach_point = BPF_TC_INGRESS); /* set opts as NULL, as we're not really interested in * getting any info for a particular filter, but just * detecting its presence. */ r = bpf_tc_query(&hook, NULL); if (r == -ENOENT) { /* no filters */ hook.attach_point = BPF_TC_INGRESS|BPF_TC_EGREESS; return bpf_tc_hook_destroy(&hook); } else { /* failed or r == 0, the latter means filters do exist */ return r; } Note that there is a small race between checking for no filters and deleting the qdisc. This is currently unavoidable. Returns -EOPNOTSUPP when hook has attach_point as BPF_TC_CUSTOM. bpf_tc_attach - Attach a filter to a hook Parameters: @hook - Cannot be NULL. Represents the hook the filter will be attached to. Requirements for ifindex and attach_point are same as described in bpf_tc_hook_create, but BPF_TC_CUSTOM is also supported. In that case, parent must be set to the handle where the filter will be attached (using BPF_TC_PARENT). E.g. to set parent to 1:16 like in tc command line, the equivalent would be BPF_TC_PARENT(1, 16). @opts - Cannot be NULL. The following opts are optional: * handle - The handle of the filter * priority - The priority of the filter Must be >= 0 and <= UINT16_MAX Note that when left unset, they will be auto-allocated by the kernel. The following opts must be set: * prog_fd - The fd of the loaded SCHED_CLS prog The following opts must be unset: * prog_id - The ID of the BPF prog The following opts are optional: * flags - Currently only BPF_TC_F_REPLACE is allowed. It allows replacing an existing filter instead of failing with -EEXIST. The following opts will be filled by bpf_tc_attach on a successful attach operation if they are unset: * handle - The handle of the attached filter * priority - The priority of the attached filter * prog_id - The ID of the attached SCHED_CLS prog This way, the user can know what the auto allocated values for optional opts like handle and priority are for the newly attached filter, if they were unset. Note that some other attributes are set to fixed default values listed below (this holds for all bpf_tc_* APIs): protocol as ETH_P_ALL, direct action mode, chain index of 0, and class ID of 0 (this can be set by writing to the skb->tc_classid field from the BPF program). bpf_tc_detach Parameters: @hook - Cannot be NULL. Represents the hook the filter will be detached from. Requirements are same as described above in bpf_tc_attach. @opts - Cannot be NULL. The following opts must be set: * handle, priority The following opts must be unset: * prog_fd, prog_id, flags bpf_tc_query Parameters: @hook - Cannot be NULL. Represents the hook where the filter lookup will be performed. Requirements are same as described above in bpf_tc_attach(). @opts - Cannot be NULL. The following opts must be set: * handle, priority The following opts must be unset: * prog_fd, prog_id, flags The following fields will be filled by bpf_tc_query upon a successful lookup: * prog_id Some usage examples (using BPF skeleton infrastructure): BPF program (test_tc_bpf.c): #include <linux/bpf.h> #include <bpf/bpf_helpers.h> SEC("classifier") int cls(struct __sk_buff *skb) { return 0; } Userspace loader: struct test_tc_bpf *skel = NULL; int fd, r; skel = test_tc_bpf__open_and_load(); if (!skel) return -ENOMEM; fd = bpf_program__fd(skel->progs.cls); DECLARE_LIBBPF_OPTS(bpf_tc_hook, hook, .ifindex = if_nametoindex("lo"), .attach_point = BPF_TC_INGRESS); /* Create clsact qdisc */ r = bpf_tc_hook_create(&hook); if (r < 0) goto end; DECLARE_LIBBPF_OPTS(bpf_tc_opts, opts, .prog_fd = fd); r = bpf_tc_attach(&hook, &opts); if (r < 0) goto end; /* Print the auto allocated handle and priority */ printf("Handle=%u", opts.handle); printf("Priority=%u", opts.priority); opts.prog_fd = opts.prog_id = 0; bpf_tc_detach(&hook, &opts); end: test_tc_bpf__destroy(skel); This is equivalent to doing the following using tc command line: # tc qdisc add dev lo clsact # tc filter add dev lo ingress bpf obj foo.o sec classifier da # tc filter del dev lo ingress handle <h> prio <p> bpf ... where the handle and priority can be found using: # tc filter show dev lo ingress Another example replacing a filter (extending prior example): /* We can also choose both (or one), let's try replacing an * existing filter. */ DECLARE_LIBBPF_OPTS(bpf_tc_opts, replace_opts, .handle = opts.handle, .priority = opts.priority, .prog_fd = fd); r = bpf_tc_attach(&hook, &replace_opts); if (r == -EEXIST) { /* Expected, now use BPF_TC_F_REPLACE to replace it */ replace_opts.flags = BPF_TC_F_REPLACE; return bpf_tc_attach(&hook, &replace_opts); } else if (r < 0) { return r; } /* There must be no existing filter with these * attributes, so cleanup and return an error. */ replace_opts.prog_fd = replace_opts.prog_id = 0; bpf_tc_detach(&hook, &replace_opts); return -1; To obtain info of a particular filter: /* Find info for filter with handle 1 and priority 50 */ DECLARE_LIBBPF_OPTS(bpf_tc_opts, info_opts, .handle = 1, .priority = 50); r = bpf_tc_query(&hook, &info_opts); if (r == -ENOENT) printf("Filter not found"); else if (r < 0) return r; printf("Prog ID: %u", info_opts.prog_id); return 0; Signed-off-by: NKumar Kartikeya Dwivedi <memxor@gmail.com> Co-developed-by: Daniel Borkmann <daniel@iogearbox.net> # libbpf API design [ Daniel: also did major patch cleanup ] Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Reviewed-by: NToke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20210512103451.989420-3-memxor@gmail.com
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- 12 5月, 2021 1 次提交
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由 Andrii Nakryiko 提交于
For better future extensibility add per-file linker options. Currently the set of available options is empty. This changes bpf_linker__add_file() API, but it's not a breaking change as bpf_linker APIs hasn't been released yet. Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210507054119.270888-3-andrii@kernel.org
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- 09 4月, 2021 1 次提交
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由 Andrii Nakryiko 提交于
The API gives access to inner map for map in map types (array or hash of map). It will be used to dynamically set max_entries in it. Signed-off-by: NYauheni Kaliuta <yauheni.kaliuta@redhat.com> Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210408061310.95877-7-yauheni.kaliuta@redhat.com
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- 26 3月, 2021 2 次提交
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由 Rafael David Tinoco 提交于
Unfortunately some distros don't have their kernel version defined accurately in <linux/version.h> due to different long term support reasons. It is important to have a way to override the bpf kern_version attribute during runtime: some old kernels might still check for kern_version attribute during bpf_prog_load(). Signed-off-by: NRafael David Tinoco <rafaeldtinoco@ubuntu.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NAndrii Nakryiko <andrii@kernel.org> Acked-by: NJohn Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210323040952.2118241-1-rafaeldtinoco@ubuntu.com
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由 Andrii Nakryiko 提交于
bpf_program__get_type() and bpf_program__get_expected_attach_type() shouldn't modify given bpf_program, so mark input parameter as const struct bpf_program. This eliminates unnecessary compilation warnings or explicit casts in user programs. Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210324172941.2609884-1-andrii@kernel.org
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- 19 3月, 2021 1 次提交
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由 Andrii Nakryiko 提交于
Introduce BPF static linker APIs to libbpf. BPF static linker allows to perform static linking of multiple BPF object files into a single combined resulting object file, preserving all the BPF programs, maps, global variables, etc. Data sections (.bss, .data, .rodata, .maps, maps, etc) with the same name are concatenated together. Similarly, code sections are also concatenated. All the symbols and ELF relocations are also concatenated in their respective ELF sections and are adjusted accordingly to the new object file layout. Static variables and functions are handled correctly as well, adjusting BPF instructions offsets to reflect new variable/function offset within the combined ELF section. Such relocations are referencing STT_SECTION symbols and that stays intact. Data sections in different files can have different alignment requirements, so that is taken care of as well, adjusting sizes and offsets as necessary to satisfy both old and new alignment requirements. DWARF data sections are stripped out, currently. As well as LLLVM_ADDRSIG section, which is ignored by libbpf in bpf_object__open() anyways. So, in a way, BPF static linker is an analogue to `llvm-strip -g`, which is a pretty nice property, especially if resulting .o file is then used to generate BPF skeleton. Original string sections are ignored and instead we construct our own set of unique strings using libbpf-internal `struct strset` API. To reduce the size of the patch, all the .BTF and .BTF.ext processing was moved into a separate patch. The high-level API consists of just 4 functions: - bpf_linker__new() creates an instance of BPF static linker. It accepts output filename and (currently empty) options struct; - bpf_linker__add_file() takes input filename and appends it to the already processed ELF data; it can be called multiple times, one for each BPF ELF object file that needs to be linked in; - bpf_linker__finalize() needs to be called to dump final ELF contents into the output file, specified when bpf_linker was created; after bpf_linker__finalize() is called, no more bpf_linker__add_file() and bpf_linker__finalize() calls are allowed, they will return error; - regardless of whether bpf_linker__finalize() was called or not, bpf_linker__free() will free up all the used resources. Currently, BPF static linker doesn't resolve cross-object file references (extern variables and/or functions). This will be added in the follow up patch set. Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210318194036.3521577-7-andrii@kernel.org
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- 17 3月, 2021 1 次提交
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由 Andrii Nakryiko 提交于
Adding such anonymous padding fixes the issue with uninitialized portions of bpf_xdp_set_link_opts when using LIBBPF_DECLARE_OPTS macro with inline field initialization: DECLARE_LIBBPF_OPTS(bpf_xdp_set_link_opts, opts, .old_fd = -1); When such code is compiled in debug mode, compiler is generating code that leaves padding bytes uninitialized, which triggers error inside libbpf APIs that do strict zero initialization checks for OPTS structs. Adding anonymous padding field fixes the issue. Fixes: bd5ca3ef ("libbpf: Add function to set link XDP fd while specifying old program") Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210313210920.1959628-2-andrii@kernel.org
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- 15 12月, 2020 1 次提交
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由 Brendan Jackman 提交于
This provides a convenient perf ringbuf -> libbpf ringbuf migration path for users of external polling systems. It is analogous to perf_buffer__epoll_fd. Signed-off-by: NBrendan Jackman <jackmanb@google.com> Signed-off-by: NAndrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20201214113812.305274-1-jackmanb@google.com
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- 30 9月, 2020 1 次提交
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由 Toke Høiland-Jørgensen 提交于
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: NToke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NAndrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/160138355387.48470.18026176785351166890.stgit@toke.dk
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- 04 9月, 2020 1 次提交
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由 Andrii Nakryiko 提交于
BPF program title is ambigious and misleading term. It is ELF section name, so let's just call it that and deprecate bpf_program__title() API in favor of bpf_program__section_name(). Additionally, using bpf_object__find_program_by_title() is now inherently dangerous and ambiguous, as multiple BPF program can have the same section name. So deprecate this API as well and recommend to switch to non-ambiguous bpf_object__find_program_by_name(). Internally, clean up usage and mis-usage of BPF program section name for denoting BPF program name. Shorten the field name to prog->sec_name to be consistent with all other prog->sec_* variables. Signed-off-by: NAndrii Nakryiko <andriin@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200903203542.15944-11-andriin@fb.com
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- 22 8月, 2020 1 次提交
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由 Andrii Nakryiko 提交于
Add a set of APIs to perf_buffer manage to allow applications to integrate perf buffer polling into existing epoll-based infrastructure. One example is applications using libevent already and wanting to plug perf_buffer polling, instead of relying on perf_buffer__poll() and waste an extra thread to do it. But perf_buffer is still extremely useful to set up and consume perf buffer rings even for such use cases. So to accomodate such new use cases, add three new APIs: - perf_buffer__buffer_cnt() returns number of per-CPU buffers maintained by given instance of perf_buffer manager; - perf_buffer__buffer_fd() returns FD of perf_event corresponding to a specified per-CPU buffer; this FD is then polled independently; - perf_buffer__consume_buffer() consumes data from single per-CPU buffer, identified by its slot index. To support a simpler, but less efficient, way to integrate perf_buffer into external polling logic, also expose underlying epoll FD through perf_buffer__epoll_fd() API. It will need to be followed by perf_buffer__poll(), wasting extra syscall, or perf_buffer__consume(), wasting CPU to iterate buffers with no data. But could be simpler and more convenient for some cases. These APIs allow for great flexiblity, but do not sacrifice general usability of perf_buffer. Also exercise and check new APIs in perf_buffer selftest. Signed-off-by: NAndrii Nakryiko <andriin@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Reviewed-by: NAlan Maguire <alan.maguire@oracle.com> Link: https://lore.kernel.org/bpf/20200821165927.849538-1-andriin@fb.com
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- 07 8月, 2020 1 次提交
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由 Yonghong Song 提交于
Previous commit adjusted kernel uapi for map element bpf iterator. This patch adjusted libbpf API due to uapi change. bpftool and bpf_iter selftests are also changed accordingly. Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NAndrii Nakryiko <andriin@fb.com> Acked-by: NJohn Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200805055058.1457623-1-yhs@fb.com
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- 02 8月, 2020 1 次提交
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由 Andrii Nakryiko 提交于
Add low-level bpf_link_detach() API. Also add higher-level bpf_link__detach() one. Signed-off-by: NAndrii Nakryiko <andriin@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NSong Liu <songliubraving@fb.com> Acked-by: NJohn Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200731182830.286260-3-andriin@fb.com
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- 26 7月, 2020 2 次提交
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由 Andrii Nakryiko 提交于
Sync UAPI header and add support for using bpf_link-based XDP attachment. Make xdp/ prog type set expected attach type. Kernel didn't enforce attach_type for XDP programs before, so there is no backwards compatiblity issues there. Also fix section_names selftest to recognize that xdp prog types now have expected attach type. Signed-off-by: NAndrii Nakryiko <andriin@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200722064603.3350758-8-andriin@fb.com
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由 Yonghong Song 提交于
Add map_fd to bpf_iter_attach_opts and flags to bpf_link_create_opts. Later on, bpftool or selftest will be able to create a bpf map element iterator by passing map_fd to the kernel during link creation time. Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184117.590673-1-yhs@fb.com
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- 18 7月, 2020 1 次提交
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由 Jakub Sitnicki 提交于
Make libbpf aware of the newly added program type, and assign it a section name. Signed-off-by: NJakub Sitnicki <jakub@cloudflare.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NAndrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200717103536.397595-13-jakub@cloudflare.com
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- 29 6月, 2020 1 次提交
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由 Andrii Nakryiko 提交于
Currently, bpf_object__load() (and by induction skeleton's load), will always attempt to prepare, relocate, and load into kernel every single BPF program found inside the BPF object file. This is often convenient and the right thing to do and what users expect. But there are plenty of cases (especially with BPF development constantly picking up the pace), where BPF application is intended to work with old kernels, with potentially reduced set of features. But on kernels supporting extra features, it would like to take a full advantage of them, by employing extra BPF program. This could be a choice of using fentry/fexit over kprobe/kretprobe, if kernel is recent enough and is built with BTF. Or BPF program might be providing optimized bpf_iter-based solution that user-space might want to use, whenever available. And so on. With libbpf and BPF CO-RE in particular, it's advantageous to not have to maintain two separate BPF object files to achieve this. So to enable such use cases, this patch adds ability to request not auto-loading chosen BPF programs. In such case, libbpf won't attempt to perform relocations (which might fail due to old kernel), won't try to resolve BTF types for BTF-aware (tp_btf/fentry/fexit/etc) program types, because BTF might not be present, and so on. Skeleton will also automatically skip auto-attachment step for such not loaded BPF programs. Overall, this feature allows to simplify development and deployment of real-world BPF applications with complicated compatibility requirements. Signed-off-by: NAndrii Nakryiko <andriin@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200625232629.3444003-2-andriin@fb.com
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- 23 6月, 2020 1 次提交
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由 Andrii Nakryiko 提交于
Add a bunch of getter for various aspects of BPF map. Some of these attribute (e.g., key_size, value_size, type, etc) are available right now in struct bpf_map_def, but this patch adds getter allowing to fetch them individually. bpf_map_def approach isn't very scalable, when ABI stability requirements are taken into account. It's much easier to extend libbpf and add support for new features, when each aspect of BPF map has separate getter/setter. Getters follow the common naming convention of not explicitly having "get" in its name: bpf_map__type() returns map type, bpf_map__key_size() returns key_size. Setters, though, explicitly have set in their name: bpf_map__set_type(), bpf_map__set_key_size(). This patch ensures we now have a getter and a setter for the following map attributes: - type; - max_entries; - map_flags; - numa_node; - key_size; - value_size; - ifindex. bpf_map__resize() enforces unnecessary restriction of max_entries > 0. It is unnecessary, because libbpf actually supports zero max_entries for some cases (e.g., for PERF_EVENT_ARRAY map) and treats it specially during map creation time. To allow setting max_entries=0, new bpf_map__set_max_entries() setter is added. bpf_map__resize()'s behavior is preserved for backwards compatibility reasons. Map ifindex getter is added as well. There is a setter already, but no corresponding getter. Fix this assymetry as well. bpf_map__set_ifindex() itself is converted from void function into error-returning one, similar to other setters. The only error returned right now is -EBUSY, if BPF map is already loaded and has corresponding FD. One lacking attribute with no ability to get/set or even specify it declaratively is numa_node. This patch fixes this gap and both adds programmatic getter/setter, as well as adds support for numa_node field in BTF-defined map. Signed-off-by: NAndrii Nakryiko <andriin@fb.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NToke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20200621062112.3006313-1-andriin@fb.com
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- 02 6月, 2020 3 次提交
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由 Jakub Sitnicki 提交于
Add bpf_program__attach_nets(), which uses LINK_CREATE subcommand to create an FD-based kernel bpf_link, for attach types tied to network namespace, that is BPF_FLOW_DISSECTOR for the moment. Signed-off-by: NJakub Sitnicki <jakub@cloudflare.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200531082846.2117903-7-jakub@cloudflare.com
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由 Andrii Nakryiko 提交于
Declaring and instantiating BPF ring buffer doesn't require any changes to libbpf, as it's just another type of maps. So using existing BTF-defined maps syntax with __uint(type, BPF_MAP_TYPE_RINGBUF) and __uint(max_elements, <size-of-ring-buf>) is all that's necessary to create and use BPF ring buffer. This patch adds BPF ring buffer consumer to libbpf. It is very similar to perf_buffer implementation in terms of API, but also attempts to fix some minor problems and inconveniences with existing perf_buffer API. ring_buffer support both single ring buffer use case (with just using ring_buffer__new()), as well as allows to add more ring buffers, each with its own callback and context. This allows to efficiently poll and consume multiple, potentially completely independent, ring buffers, using single epoll instance. The latter is actually a problem in practice for applications that are using multiple sets of perf buffers. They have to create multiple instances for struct perf_buffer and poll them independently or in a loop, each approach having its own problems (e.g., inability to use a common poll timeout). struct ring_buffer eliminates this problem by aggregating many independent ring buffer instances under the single "ring buffer manager". Second, perf_buffer's callback can't return error, so applications that need to stop polling due to error in data or data signalling the end, have to use extra mechanisms to signal that polling has to stop. ring_buffer's callback can return error, which will be passed through back to user code and can be acted upon appropariately. Two APIs allow to consume ring buffer data: - ring_buffer__poll(), which will wait for data availability notification and will consume data only from reported ring buffer(s); this API allows to efficiently use resources by reading data only when it becomes available; - ring_buffer__consume(), will attempt to read new records regardless of data availablity notification sub-system. This API is useful for cases when lowest latency is required, in expense of burning CPU resources. Signed-off-by: NAndrii Nakryiko <andriin@fb.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200529075424.3139988-3-andriin@fb.comSigned-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Eelco Chaudron 提交于
This new API, perf_buffer__consume, can be used as follows: - When you have a perf ring where wakeup_events is higher than 1, and you have remaining data in the rings you would like to pull out on exit (or maybe based on a timeout). - For low latency cases where you burn a CPU that constantly polls the queues. Signed-off-by: NEelco Chaudron <echaudro@redhat.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAndrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/159048487929.89441.7465713173442594608.stgit@ebuildSigned-off-by: NAlexei Starovoitov <ast@kernel.org>
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- 10 5月, 2020 1 次提交
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由 Yonghong Song 提交于
Two new libbpf APIs are added to support bpf_iter: - bpf_program__attach_iter Given a bpf program and additional parameters, which is none now, returns a bpf_link. - bpf_iter_create syscall level API to create a bpf iterator. The macro BPF_SEQ_PRINTF are also introduced. The format looks like: BPF_SEQ_PRINTF(seq, "task id %d\n", pid); This macro can help bpf program writers with nicer bpf_seq_printf syntax similar to the kernel one. Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NAndrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200509175917.2476936-1-yhs@fb.com
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- 15 4月, 2020 1 次提交
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由 Toke Høiland-Jørgensen 提交于
The 'old_fd' parameter used for atomic replacement of XDP programs is supposed to be an FD, but was left as a u32 from an earlier iteration of the patch that added it. It was converted to an int when read, so things worked correctly even with negative values, but better change the definition to correctly reflect the intention. Fixes: bd5ca3ef ("libbpf: Add function to set link XDP fd while specifying old program") Reported-by: NDavid Ahern <dsahern@gmail.com> Signed-off-by: NToke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NDavid Ahern <dsahern@gmail.com> Acked-by: NSong Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200414145025.182163-1-toke@redhat.com
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- 31 3月, 2020 1 次提交
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由 Andrii Nakryiko 提交于
Add bpf_program__attach_cgroup(), which uses BPF_LINK_CREATE subcommand to create an FD-based kernel bpf_link. Also add low-level bpf_link_create() API. If expected_attach_type is not specified explicitly with bpf_program__set_expected_attach_type(), libbpf will try to determine proper attach type from BPF program's section definition. Also add support for bpf_link's underlying BPF program replacement: - unconditional through high-level bpf_link__update_program() API; - cmpxchg-like with specifying expected current BPF program through low-level bpf_link_update() API. Signed-off-by: NAndrii Nakryiko <andriin@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200330030001.2312810-4-andriin@fb.com
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