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10ebe835 |
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14-Mar-2024 |
Alexei Starovoitov <ast@kernel.org> |
libbpf, selftests/bpf: Adjust libbpf, bpftool, selftests to match LLVM The selftests use to tell LLVM about special pointers. For LLVM there is nothing "arena" about them. They are simply pointers in a different address space. Hence LLVM diff https://github.com/llvm/llvm-project/pull/85161 renamed: . macro __BPF_FEATURE_ARENA_CAST -> __BPF_FEATURE_ADDR_SPACE_CAST . global variables in __attribute__((address_space(N))) are now placed in section named ".addr_space.N" instead of ".arena.N". Adjust libbpf, bpftool, and selftests to match LLVM. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20240315021834.62988-3-alexei.starovoitov@gmail.com
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#
2e7ba4f8 |
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07-Mar-2024 |
Andrii Nakryiko <andrii@kernel.org> |
libbpf: Recognize __arena global variables. LLVM automatically places __arena variables into ".arena.1" ELF section. In order to use such global variables bpf program must include definition of arena map in ".maps" section, like: struct { __uint(type, BPF_MAP_TYPE_ARENA); __uint(map_flags, BPF_F_MMAPABLE); __uint(max_entries, 1000); /* number of pages */ __ulong(map_extra, 2ull << 44); /* start of mmap() region */ } arena SEC(".maps"); libbpf recognizes both uses of arena and creates single `struct bpf_map *` instance in libbpf APIs. ".arena.1" ELF section data is used as initial data image, which is exposed through skeleton and bpf_map__initial_value() to the user, if they need to tune it before the load phase. During load phase, this initial image is copied over into mmap()'ed region corresponding to arena, and discarded. Few small checks here and there had to be added to make sure this approach works with bpf_map__initial_value(), mostly due to hard-coded assumption that map->mmaped is set up with mmap() syscall and should be munmap()'ed. For arena, .arena.1 can be (much) smaller than maximum arena size, so this smaller data size has to be tracked separately. Given it is enforced that there is only one arena for entire bpf_object instance, we just keep it in a separate field. This can be generalized if necessary later. All global variables from ".arena.1" section are accessible from user space via skel->arena->name_of_var. For bss/data/rodata the skeleton/libbpf perform the following sequence: 1. addr = mmap(MAP_ANONYMOUS) 2. user space optionally modifies global vars 3. map_fd = bpf_create_map() 4. bpf_update_map_elem(map_fd, addr) // to store values into the kernel 5. mmap(addr, MAP_FIXED, map_fd) after step 5 user spaces see the values it wrote at step 2 at the same addresses arena doesn't support update_map_elem. Hence skeleton/libbpf do: 1. addr = malloc(sizeof SEC ".arena.1") 2. user space optionally modifies global vars 3. map_fd = bpf_create_map(MAP_TYPE_ARENA) 4. real_addr = mmap(map->map_extra, MAP_SHARED | MAP_FIXED, map_fd) 5. memcpy(real_addr, addr) // this will fault-in and allocate pages At the end look and feel of global data vs __arena global data is the same from bpf prog pov. Another complication is: struct { __uint(type, BPF_MAP_TYPE_ARENA); } arena SEC(".maps"); int __arena foo; int bar; ptr1 = &foo; // relocation against ".arena.1" section ptr2 = &arena; // relocation against ".maps" section ptr3 = &bar; // relocation against ".bss" section Fo the kernel ptr1 and ptr2 has point to the same arena's map_fd while ptr3 points to a different global array's map_fd. For the verifier: ptr1->type == unknown_scalar ptr2->type == const_ptr_to_map ptr3->type == ptr_to_map_value After verification, from JIT pov all 3 ptr-s are normal ld_imm64 insns. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20240308010812.89848-11-alexei.starovoitov@gmail.com
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#
1576b079 |
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06-Mar-2024 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: rename is_internal_mmapable_map into is_mmapable_map It's not restricted to working with "internal" maps, it cares about any map that can be mmap'ed. Reflect that in more succinct and generic name. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/r/20240307031228.42896-6-alexei.starovoitov@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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#
a7b0fa35 |
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28-Feb-2024 |
Kui-Feng Lee <thinker.li@gmail.com> |
bpftool: Generated shadow variables for struct_ops maps. Declares and defines a pointer of the shadow type for each struct_ops map. The code generator will create an anonymous struct type as the shadow type for each struct_ops map. The shadow type is translated from the original struct type of the map. The user of the skeleton use pointers of them to access the values of struct_ops maps. However, shadow types only supports certain types of fields, including scalar types and function pointers. Any fields of unsupported types are translated into an array of characters to occupy the space of the original field. Function pointers are translated into pointers of the struct bpf_program. Additionally, padding fields are generated to occupy the space between two consecutive fields. The pointers of shadow types of struct_osp maps are initialized when *__open_opts() in skeletons are called. For a map called FOO, the user can access it through the pointer at skel->struct_ops.FOO. Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20240229064523.2091270-4-thinker.li@gmail.com
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#
29788f39 |
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29-Jan-2024 |
Arnaldo Carvalho de Melo <acme@kernel.org> |
bpftool: Be more portable by using POSIX's basename() musl libc had the basename() prototype in string.h, but this is a glibc-ism, now they removed the _GNU_SOURCE bits in their devel distro, Alpine Linux edge: https://git.musl-libc.org/cgit/musl/commit/?id=725e17ed6dff4d0cd22487bb64470881e86a92e7 So lets use the POSIX version, the whole rationale is spelled out at: https://gitlab.alpinelinux.org/alpine/aports/-/issues/15643 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Olsa <olsajiri@gmail.com> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/lkml/ZZhsPs00TI75RdAr@kernel.org Link: https://lore.kernel.org/bpf/Zbe3NuOgaupvUcpF@kernel.org
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#
1be84ca5 |
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06-Oct-2023 |
Ian Rogers <irogers@google.com> |
bpftool: Align bpf_load_and_run_opts insns and data A C string lacks alignment so use aligned arrays to avoid potential alignment problems. Switch to using sizeof (less 1 for the \0 terminator) rather than a hardcode size constant. Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20231007044439.25171-2-irogers@google.com
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#
23671f4d |
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06-Oct-2023 |
Ian Rogers <irogers@google.com> |
bpftool: Align output skeleton ELF code libbpf accesses the ELF data requiring at least 8 byte alignment, however, the data is generated into a C string that doesn't guarantee alignment. Fix this by assigning to an aligned char array. Use sizeof on the array, less one for the \0 terminator, rather than generating a constant. Fixes: a6cc6b34b93e ("bpftool: Provide a helper method for accessing skeleton's embedded ELF data") Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20231007044439.25171-1-irogers@google.com
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#
ebc8484d |
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07-Sep-2023 |
Denys Zagorui <dzagorui@cisco.com> |
bpftool: Fix -Wcast-qual warning This cast was made by purpose for older libbpf where the bpf_object_skeleton field is void * instead of const void * to eliminate a warning (as i understand -Wincompatible-pointer-types-discards-qualifiers) but this cast introduces another warning (-Wcast-qual) for libbpf where data field is const void * It makes sense for bpftool to be in sync with libbpf from kernel sources Signed-off-by: Denys Zagorui <dzagorui@cisco.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20230907090210.968612-1-dzagorui@cisco.com
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#
d1313e01 |
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20-Nov-2022 |
Sahid Orentino Ferdjaoui <sahid.ferdjaoui@industrialdiscipline.com> |
bpftool: clean-up usage of libbpf_get_error() bpftool is now totally compliant with libbpf 1.0 mode and is not expected to be compiled with pre-1.0, let's clean-up the usage of libbpf_get_error(). The changes stay aligned with returned errors always negative. - In tools/bpf/bpftool/btf.c This fixes an uninitialized local variable `err` in function do_dump() because it may now be returned without having been set. - This also removes the checks on NULL pointers before calling btf__free() because that function already does the check. Signed-off-by: Sahid Orentino Ferdjaoui <sahid.ferdjaoui@industrialdiscipline.com> Link: https://lore.kernel.org/r/20221120112515.38165-5-sahid.ferdjaoui@industrialdiscipline.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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#
c302378b |
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09-Nov-2022 |
Eduard Zingerman <eddyz87@gmail.com> |
libbpf: Hashmap interface update to allow both long and void* keys/values An update for libbpf's hashmap interface from void* -> void* to a polymorphic one, allowing both long and void* keys and values. This simplifies many use cases in libbpf as hashmaps there are mostly integer to integer. Perf copies hashmap implementation from libbpf and has to be updated as well. Changes to libbpf, selftests/bpf and perf are packed as a single commit to avoid compilation issues with any future bisect. Polymorphic interface is acheived by hiding hashmap interface functions behind auxiliary macros that take care of necessary type casts, for example: #define hashmap_cast_ptr(p) \ ({ \ _Static_assert((p) == NULL || sizeof(*(p)) == sizeof(long),\ #p " pointee should be a long-sized integer or a pointer"); \ (long *)(p); \ }) bool hashmap_find(const struct hashmap *map, long key, long *value); #define hashmap__find(map, key, value) \ hashmap_find((map), (long)(key), hashmap_cast_ptr(value)) - hashmap__find macro casts key and value parameters to long and long* respectively - hashmap_cast_ptr ensures that value pointer points to a memory of appropriate size. This hack was suggested by Andrii Nakryiko in [1]. This is a follow up for [2]. [1] https://lore.kernel.org/bpf/CAEf4BzZ8KFneEJxFAaNCCFPGqp20hSpS2aCj76uRk3-qZUH5xg@mail.gmail.com/ [2] https://lore.kernel.org/bpf/af1facf9-7bc8-8a3d-0db4-7b3f333589a2@meta.com/T/#m65b28f1d6d969fcd318b556db6a3ad499a42607d Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221109142611.879983-2-eddyz87@gmail.com
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#
3ca2fb49 |
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28-Sep-2022 |
Tianyi Liu <i.pear@outlook.com> |
bpftool: Fix error message of strerror strerror() expects a positive errno, however variable err will never be positive when an error occurs. This causes bpftool to output too many "unknown error", even a simple "file not exist" error can not get an accurate message. This patch fixed all "strerror(err)" patterns in bpftool. Specially in btf.c#L823, hashmap__append() is an internal function of libbpf and will not change errno, so there's a little difference. Some libbpf_get_error() calls are kept for return values. Changes since v1: https://lore.kernel.org/bpf/SY4P282MB1084B61CD8671DFA395AA8579D539@SY4P282MB1084.AUSP282.PROD.OUTLOOK.COM/ Check directly for NULL values instead of calling libbpf_get_error(). Signed-off-by: Tianyi Liu <i.pear@outlook.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/SY4P282MB1084AD9CD84A920F08DF83E29D549@SY4P282MB1084.AUSP282.PROD.OUTLOOK.COM
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#
a6df0674 |
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26-Jul-2022 |
Jörn-Thorben Hinz <jthinz@mailbox.tu-berlin.de> |
bpftool: Don't try to return value from void function in skeleton A skeleton generated by bpftool previously contained a return followed by an expression in OBJ_NAME__detach(), which has return type void. This did not hurt, the bpf_object__detach_skeleton() called there returns void itself anyway, but led to a warning when compiling with e.g. -pedantic. Signed-off-by: Jörn-Thorben Hinz <jthinz@mailbox.tu-berlin.de> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20220726133203.514087-1-jthinz@mailbox.tu-berlin.de
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#
aad53f17 |
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06-Jul-2022 |
Daniel Müller <deso@posteo.net> |
bpftool: Add support for KIND_RESTRICT to gen min_core_btf command This change adjusts bpftool's type marking logic, as used in conjunction with TYPE_EXISTS relocations, to correctly recognize and handle the RESTRICT BTF kind. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20220623212205.2805002-1-deso@posteo.net/T/#m4c75205145701762a4b398e0cdb911d5b5305ffc Link: https://lore.kernel.org/bpf/20220706212855.1700615-2-deso@posteo.net
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#
633e7ceb |
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28-Jun-2022 |
Daniel Müller <deso@posteo.net> |
bpftool: Honor BPF_CORE_TYPE_MATCHES relocation 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
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#
58a53978 |
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07-Jun-2022 |
Yonghong Song <yhs@fb.com> |
bpftool: Add btf enum64 support Add BTF_KIND_ENUM64 support. For example, the following enum is defined in uapi bpf.h. $ cat core.c enum A { BPF_F_INDEX_MASK = 0xffffffffULL, BPF_F_CURRENT_CPU = BPF_F_INDEX_MASK, BPF_F_CTXLEN_MASK = (0xfffffULL << 32), } g; Compiled with clang -target bpf -O2 -g -c core.c Using bpftool to dump types and generate format C file: $ bpftool btf dump file core.o ... [1] ENUM64 'A' encoding=UNSIGNED size=8 vlen=3 'BPF_F_INDEX_MASK' val=4294967295ULL 'BPF_F_CURRENT_CPU' val=4294967295ULL 'BPF_F_CTXLEN_MASK' val=4503595332403200ULL $ bpftool btf dump file core.o format c ... enum A { BPF_F_INDEX_MASK = 4294967295ULL, BPF_F_CURRENT_CPU = 4294967295ULL, BPF_F_CTXLEN_MASK = 4503595332403200ULL, }; ... Note that for raw btf output, the encoding (UNSIGNED or SIGNED) is printed out as well. The 64bit value is also represented properly in BTF and C dump. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220607062652.3722649-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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#
de4b4b94 |
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23-May-2022 |
Michael Mullin <masmullin@gmail.com> |
bpftool: Check for NULL ptr of btf in codegen_asserts bpf_object__btf() can return a NULL value. If bpf_object__btf returns null, do not progress through codegen_asserts(). This avoids a null ptr dereference at the call btf__type_cnt() in the function find_type_for_map() Signed-off-by: Michael Mullin <masmullin@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220523194917.igkgorco42537arb@jup
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#
bd2331b3 |
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09-May-2022 |
KP Singh <kpsingh@kernel.org> |
bpftool: bpf_link_get_from_fd support for LSM programs in lskel bpf_link_get_from_fd currently returns a NULL fd for LSM programs. LSM programs are similar to tracing programs and can also use skel_raw_tracepoint_open. Signed-off-by: KP Singh <kpsingh@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220509214905.3754984-1-kpsingh@kernel.org
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56c3e749 |
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09-May-2022 |
Jason Wang <jasowang@redhat.com> |
bpftool: Declare generator name Most code generators declare its name so did this for bfptool. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220509090247.5457-1-jasowang@redhat.com
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522574fd |
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21-Mar-2022 |
Delyan Kratunov <delyank@fb.com> |
bpftool: Explicit errno handling in skeletons Andrii noticed that since f97b8b9bd630 ("bpftool: Fix a bug in subskeleton code generation") the subskeleton code allows bpf_object__destroy_subskeleton to overwrite the errno that subskeleton__open would return with. While this is not currently an issue, let's make it future-proof. This patch explicitly tracks err in subskeleton__open and skeleton__create (i.e. calloc failure is explicitly ENOMEM) and ensures that errno is -err on the error return path. The skeleton code had to be changed since maps and progs codegen is shared with subskeletons. Fixes: f97b8b9bd630 ("bpftool: Fix a bug in subskeleton code generation") Signed-off-by: Delyan Kratunov <delyank@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/3b6bfbb770c79ae64d8de26c1c1bd9d53a4b85f8.camel@fb.com
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#
ef8a257b |
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28-Mar-2022 |
Jiri Olsa <jolsa@kernel.org> |
bpftool: Fix generated code in codegen_asserts Arnaldo reported perf compilation fail with: $ make -k BUILD_BPF_SKEL=1 CORESIGHT=1 PYTHON=python3 ... In file included from util/bpf_counter.c:28: /tmp/build/perf//util/bpf_skel/bperf_leader.skel.h: In function ‘bperf_leader_bpf__assert’: /tmp/build/perf//util/bpf_skel/bperf_leader.skel.h:351:51: error: unused parameter ‘s’ [-Werror=unused-parameter] 351 | bperf_leader_bpf__assert(struct bperf_leader_bpf *s) | ~~~~~~~~~~~~~~~~~~~~~~~~~^ cc1: all warnings being treated as errors If there's nothing to generate in the new assert function, we will get unused 's' warn/error, adding 'unused' attribute to it. Fixes: 08d4dba6ae77 ("bpftool: Bpf skeletons assert type sizes") Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Link: https://lore.kernel.org/bpf/20220328083703.2880079-1-jolsa@kernel.org
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#
f97b8b9b |
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19-Mar-2022 |
Yonghong Song <yhs@fb.com> |
bpftool: Fix a bug in subskeleton code generation Compiled with clang by adding LLVM=1 both kernel and selftests/bpf build, I hit the following compilation error: In file included from /.../tools/testing/selftests/bpf/prog_tests/subskeleton.c:6: ./test_subskeleton_lib.subskel.h:168:6: error: variable 'err' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] if (!s->progs) ^~~~~~~~~ ./test_subskeleton_lib.subskel.h:181:11: note: uninitialized use occurs here errno = -err; ^~~ ./test_subskeleton_lib.subskel.h:168:2: note: remove the 'if' if its condition is always false if (!s->progs) ^~~~~~~~~~~~~~ The compilation error is triggered by the following code ... int err; obj = (struct test_subskeleton_lib *)calloc(1, sizeof(*obj)); if (!obj) { errno = ENOMEM; goto err; } ... err: test_subskeleton_lib__destroy(obj); errno = -err; ... in test_subskeleton_lib__open(). The 'err' is not initialized, yet it is used in 'errno = -err' later. The fix is to remove 'errno = -err' since errno has been set properly in all incoming branches. Fixes: 00389c58ffe9 ("bpftool: Add support for subskeletons") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220320032009.3106133-1-yhs@fb.com
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#
00389c58 |
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16-Mar-2022 |
Delyan Kratunov <delyank@fb.com> |
bpftool: Add support for subskeletons Subskeletons are headers which require an already loaded program to operate. For example, when a BPF library is linked into a larger BPF object file, the library userspace needs a way to access its own global variables without requiring knowledge about the larger program at build time. As a result, subskeletons require a loaded bpf_object to open(). Further, they find their own symbols in the larger program by walking BTF type data at run time. At this time, programs, maps, and globals are supported through non-owning pointers. Signed-off-by: Delyan Kratunov <delyank@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/ca8a48b4841c72d285ecce82371bef4a899756cb.1647473511.git.delyank@fb.com
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#
08d4dba6 |
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23-Feb-2022 |
Delyan Kratunov <delyank@fb.com> |
bpftool: Bpf skeletons assert type sizes When emitting type declarations in skeletons, bpftool will now also emit static assertions on the size of the data/bss/rodata/etc fields. This ensures that in situations where userspace and kernel types have the same name but differ in size we do not silently produce incorrect results but instead break the build. This was reported in [1] and as expected the repro in [2] fails to build on the new size assert after this change. [1]: Closes: https://github.com/libbpf/libbpf/issues/433 [2]: https://github.com/fuweid/iovisor-bcc-pr-3777 Signed-off-by: Delyan Kratunov <delyank@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Hengqi Chen <hengqi.chen@gmail.com> Acked-by: Hengqi Chen <hengqi.chen@gmail.com> Link: https://lore.kernel.org/bpf/f562455d7b3cf338e59a7976f4690ec5a0057f7f.camel@fb.com
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#
9b6eb047 |
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16-Feb-2022 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: Fix C++ additions to skeleton Mark C++-specific T::open() and other methods as static inline to avoid symbol redefinition when multiple files use the same skeleton header in an application. Fixes: bb8ffe61ea45 ("bpftool: Add C++-specific open/load/etc skeleton wrappers") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220216233540.216642-1-andrii@kernel.org
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dc695516 |
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15-Feb-2022 |
Mauricio Vásquez <mauricio@kinvolk.io> |
bpftool: Implement btfgen_get_btf() The last part of the BTFGen algorithm is to create a new BTF object with all the types that were recorded in the previous steps. This function performs two different steps: 1. Add the types to the new BTF object by using btf__add_type(). Some special logic around struct and unions is implemented to only add the members that are really used in the field-based relocations. The type ID on the new and old BTF objects is stored on a map. 2. Fix all the type IDs on the new BTF object by using the IDs saved in the previous step. Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io> Signed-off-by: Rafael David Tinoco <rafael.tinoco@aquasec.com> Signed-off-by: Lorenzo Fontana <lorenzo.fontana@elastic.co> Signed-off-by: Leonardo Di Donato <leonardo.didonato@elastic.co> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220215225856.671072-6-mauricio@kinvolk.io
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a9caaba3 |
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15-Feb-2022 |
Mauricio Vásquez <mauricio@kinvolk.io> |
bpftool: Implement "gen min_core_btf" logic This commit implements the logic for the gen min_core_btf command. Specifically, it implements the following functions: - minimize_btf(): receives the path of a source and destination BTF files and a list of BPF objects. This function records the relocations for all objects and then generates the BTF file by calling btfgen_get_btf() (implemented in the following commit). - btfgen_record_obj(): loads the BTF and BTF.ext sections of the BPF objects and loops through all CO-RE relocations. It uses bpf_core_calc_relo_insn() from libbpf and passes the target spec to btfgen_record_reloc(), that calls one of the following functions depending on the relocation kind. - btfgen_record_field_relo(): uses the target specification to mark all the types that are involved in a field-based CO-RE relocation. In this case types resolved and marked recursively using btfgen_mark_type(). Only the struct and union members (and their types) involved in the relocation are marked to optimize the size of the generated BTF file. - btfgen_record_type_relo(): marks the types involved in a type-based CO-RE relocation. In this case no members for the struct and union types are marked as libbpf doesn't use them while performing this kind of relocation. Pointed types are marked as they are used by libbpf in this case. - btfgen_record_enumval_relo(): marks the whole enum type for enum-based relocations. Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io> Signed-off-by: Rafael David Tinoco <rafael.tinoco@aquasec.com> Signed-off-by: Lorenzo Fontana <lorenzo.fontana@elastic.co> Signed-off-by: Leonardo Di Donato <leonardo.didonato@elastic.co> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220215225856.671072-5-mauricio@kinvolk.io
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0a9f4a20 |
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15-Feb-2022 |
Mauricio Vásquez <mauricio@kinvolk.io> |
bpftool: Add gen min_core_btf command This command is implemented under the "gen" command in bpftool and the syntax is the following: $ bpftool gen min_core_btf INPUT OUTPUT OBJECT [OBJECT...] INPUT is the file that contains all the BTF types for a kernel and OUTPUT is the path of the minimize BTF file that will be created with only the types needed by the objects. Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io> Signed-off-by: Rafael David Tinoco <rafael.tinoco@aquasec.com> Signed-off-by: Lorenzo Fontana <lorenzo.fontana@elastic.co> Signed-off-by: Leonardo Di Donato <leonardo.didonato@elastic.co> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220215225856.671072-4-mauricio@kinvolk.io
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bb8ffe61 |
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11-Feb-2022 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: Add C++-specific open/load/etc skeleton wrappers Add C++-specific static methods for code-generated BPF skeleton for each skeleton operation: open, open_opts, open_and_load, load, attach, detach, destroy, and elf_bytes. This is to facilitate easier C++ templating on top of pure C BPF skeleton. In C, open/load/destroy/etc "methods" are of the form <skeleton_name>__<method>() to avoid name collision with similar "methods" of other skeletons withint the same application. This works well, but is very inconvenient for C++ applications that would like to write generic (templated) wrappers around BPF skeleton to fit in with C++ code base and take advantage of destructors and other convenient C++ constructs. This patch makes it easier to build such generic templated wrappers by additionally defining C++ static methods for skeleton's struct with fixed names. This allows to refer to, say, open method as `T::open()` instead of having to somehow generate `T__open()` function call. Next patch adds an example template to test_cpp selftest to demonstrate how it's possible to have all the operations wrapped in a generic Skeleton<my_skeleton> type without explicitly passing function references. An example of generated declaration section without %1$s placeholders: #ifdef __cplusplus static struct test_attach_probe *open(const struct bpf_object_open_opts *opts = nullptr); static struct test_attach_probe *open_and_load(); static int load(struct test_attach_probe *skel); static int attach(struct test_attach_probe *skel); static void detach(struct test_attach_probe *skel); static void destroy(struct test_attach_probe *skel); static const void *elf_bytes(size_t *sz); #endif /* __cplusplus */ Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220212055733.539056-2-andrii@kernel.org
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28d743f6 |
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09-Feb-2022 |
Alexei Starovoitov <ast@kernel.org> |
bpftool: Generalize light skeleton generation. Generealize light skeleton by hiding mmap details in skel_internal.h In this form generated lskel.h is usable both by user space and by the kernel. Note that previously #include <bpf/bpf.h> was in *.lskel.h file. To avoid #ifdef-s in a generated lskel.h the include of bpf.h is moved to skel_internal.h, but skel_internal.h is also used by gen_loader.c which is part of libbpf. Therefore skel_internal.h does #include "bpf.h" in case of user space, so gen_loader.c and lskel.h have necessary definitions. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220209232001.27490-4-alexei.starovoitov@gmail.com
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c69f94a3 |
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31-Jan-2022 |
Alexei Starovoitov <ast@kernel.org> |
libbpf: Open code raw_tp_open and link_create commands. Open code raw_tracepoint_open and link_create used by light skeleton to be able to avoid full libbpf eventually. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-4-alexei.starovoitov@gmail.com
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42d1d53f |
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31-Jan-2022 |
Alexei Starovoitov <ast@kernel.org> |
libbpf: Add support for bpf iter in light skeleton. bpf iterator programs should use bpf_link_create to attach instead of bpf_raw_tracepoint_open like other tracing programs. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-2-alexei.starovoitov@gmail.com
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39748db1 |
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24-Jan-2022 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: use preferred setters/getters instead of deprecated ones Use bpf_program__type() instead of discouraged bpf_program__get_type(). Also switch to bpf_map__set_max_entries() instead of bpf_map__resize(). Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220124194254.2051434-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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0991f6a3 |
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08-Jan-2022 |
Wei Fu <fuweid89@gmail.com> |
bpftool: Only set obj->skeleton on complete success After `bpftool gen skeleton`, the ${bpf_app}.skel.h will provide that ${bpf_app_name}__open helper to load bpf. If there is some error like ENOMEM, the ${bpf_app_name}__open will rollback(free) the allocated object, including `bpf_object_skeleton`. Since the ${bpf_app_name}__create_skeleton set the obj->skeleton first and not rollback it when error, it will cause double-free in ${bpf_app_name}__destory at ${bpf_app_name}__open. Therefore, we should set the obj->skeleton before return 0; Fixes: 5dc7a8b21144 ("bpftool, selftests/bpf: Embed object file inside skeleton") Signed-off-by: Wei Fu <fuweid89@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220108084008.1053111-1-fuweid89@gmail.com
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3c28919f |
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07-Jan-2022 |
Christy Lee <christylee@fb.com> |
bpftool: Stop using bpf_map__def() API libbpf bpf_map__def() API is being deprecated, replace bpftool's usage with the appropriate getters and setters Signed-off-by: Christy Lee <christylee@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220108004218.355761-3-christylee@fb.com
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b59e4ce8 |
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09-Dec-2021 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: Switch bpf_object__load_xattr() to bpf_object__load() Switch all the uses of to-be-deprecated bpf_object__load_xattr() into a simple bpf_object__load() calls with optional log_level passed through open_opts.kernel_log_level, if -d option is specified. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211209193840.1248570-13-andrii@kernel.org
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e5043894 |
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14-Nov-2021 |
Hengqi Chen <hengqi.chen@gmail.com> |
bpftool: Use libbpf_get_error() to check error Currently, LIBBPF_STRICT_ALL mode is enabled by default for bpftool which means on error cases, some libbpf APIs would return NULL pointers. This makes IS_ERR check failed to detect such cases and result in segfault error. Use libbpf_get_error() instead like we do in libbpf itself. Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211115012436.3143318-1-hengqi.chen@gmail.com
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164b04f2 |
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10-Nov-2021 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: Update btf_dump__new() and perf_buffer__new_raw() calls Use v1.0-compatible variants of btf_dump and perf_buffer "constructors". This is also a demonstration of reusing struct perf_buffer_raw_opts as OPTS-style option struct for new perf_buffer__new_raw() API. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211111053624.190580-10-andrii@kernel.org
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58fc155b |
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22-Oct-2021 |
Hengqi Chen <hengqi.chen@gmail.com> |
bpftool: Switch to new btf__type_cnt API Replace the call to btf__get_nr_types with new API btf__type_cnt. The old API will be deprecated in libbpf v0.7+. No functionality change. Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211022130623.1548429-5-hengqi.chen@gmail.com
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ef9356d3 |
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20-Oct-2021 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: Improve skeleton generation for data maps without DATASEC type It can happen that some data sections (e.g., .rodata.cst16, containing compiler populated string constants) won't have a corresponding BTF DATASEC type. Now that libbpf supports .rodata.* and .data.* sections, situation like that will cause invalid BPF skeleton to be generated that won't compile successfully, as some parts of skeleton would assume memory-mapped struct definitions for each special data section. Fix this by generating empty struct definitions for such data sections. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20211021014404.2635234-7-andrii@kernel.org
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8654b4d3 |
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20-Oct-2021 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: Support multiple .rodata/.data internal maps in skeleton Remove the assumption about only single instance of each of .rodata and .data internal maps. Nothing changes for '.rodata' and '.data' maps, but new '.rodata.something' map will get 'rodata_something' section in BPF skeleton for them (as well as having struct bpf_map * field in maps section with the same field name). Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20211021014404.2635234-6-andrii@kernel.org
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c66a248f |
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07-Oct-2021 |
Quentin Monnet <quentin@isovalent.com> |
bpftool: Remove unused includes to <bpf/bpf_gen_internal.h> It seems that the header file was never necessary to compile bpftool, and it is not part of the headers exported from libbpf. Let's remove the includes from prog.c and gen.c. Fixes: d510296d331a ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.") Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211007194438.34443-3-quentin@isovalent.com
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09710d82 |
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28-Sep-2021 |
Yucong Sun <fallentree@fb.com> |
bpftool: Avoid using "?: " in generated code "?:" is a GNU C extension, some environment has warning flags for its use, or even prohibit it directly. This patch avoid triggering these problems by simply expand it to its full form, no functionality change. Signed-off-by: Yucong Sun <fallentree@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210928184221.1545079-1-fallentree@fb.com
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a6cc6b34 |
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01-Sep-2021 |
Matt Smith <alastorze@fb.com> |
bpftool: Provide a helper method for accessing skeleton's embedded ELF data This adds a skeleton method X__elf_bytes() which returns the binary data of the compiled and embedded BPF object file. It additionally sets the size of the return data to the provided size_t pointer argument. The assignment to s->data is cast to void * to ensure no warning is issued if compiled with a previous version of libbpf where the bpf_object_skeleton field is void * instead of const void * Signed-off-by: Matt Smith <alastorze@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210901194439.3853238-3-alastorze@fb.com
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8cc8c635 |
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30-Jul-2021 |
Quentin Monnet <quentin@isovalent.com> |
tools: bpftool: Document and add bash completion for -L, -B options The -L|--use-loader option for using loader programs when loading, or when generating a skeleton, did not have any documentation or bash completion. Same thing goes for -B|--base-btf, used to pass a path to a base BTF object for split BTF such as BTF for kernel modules. This patch documents and adds bash completion for those options. Fixes: 75fa1777694c ("tools/bpftool: Add bpftool support for split BTF") Fixes: d510296d331a ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.") Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210730215435.7095-7-quentin@isovalent.com
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c07ba629 |
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30-Jul-2021 |
Quentin Monnet <quentin@isovalent.com> |
tools: bpftool: Update and synchronise option list in doc and help msg All bpftool commands support the options for JSON output and debug from libbpf. In addition, some commands support additional options corresponding to specific use cases. The list of options described in the man pages for the different commands are not always accurate. The messages for interactive help are mostly limited to HELP_SPEC_OPTIONS, and are even less representative of the actual set of options supported for the commands. Let's update the lists: - HELP_SPEC_OPTIONS is modified to contain the "default" options (JSON and debug), and to be extensible (no ending curly bracket). - All commands use HELP_SPEC_OPTIONS in their help message, and then complete the list with their specific options. - The lists of options in the man pages are updated. - The formatting of the list for bpftool.rst is adjusted to match formatting for the other man pages. This is for consistency, and also because it will be helpful in a future patch to automatically check that the files are synchronised. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210730215435.7095-5-quentin@isovalent.com
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9c6c0449 |
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24-May-2021 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: Set errno on skeleton failures and propagate errors Follow libbpf's error handling conventions and pass through errors and errno properly. Skeleton code always returned NULL on errors (not ERR_PTR(err)), so there are no backwards compatibility concerns. But now we also set errno properly, so it's possible to distinguish different reasons for failure, if necessary. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20210525035935.1461796-6-andrii@kernel.org
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d510296d |
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13-May-2021 |
Alexei Starovoitov <ast@kernel.org> |
bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command. Add -L flag to bpftool to use libbpf gen_trace facility and syscall/loader program for skeleton generation and program loading. "bpftool gen skeleton -L" command will generate a "light skeleton" or "loader skeleton" that is similar to existing skeleton, but has one major difference: $ bpftool gen skeleton lsm.o > lsm.skel.h $ bpftool gen skeleton -L lsm.o > lsm.lskel.h $ diff lsm.skel.h lsm.lskel.h @@ -5,34 +4,34 @@ #define __LSM_SKEL_H__ #include <stdlib.h> -#include <bpf/libbpf.h> +#include <bpf/bpf.h> The light skeleton does not use majority of libbpf infrastructure. It doesn't need libelf. It doesn't parse .o file. It only needs few sys_bpf wrappers. All of them are in bpf/bpf.h file. In future libbpf/bpf.c can be inlined into bpf.h, so not even libbpf.a would be needed to work with light skeleton. "bpftool prog load -L file.o" command is introduced for debugging of syscall/loader program generation. Just like the same command without -L it will try to load the programs from file.o into the kernel. It won't even try to pin them. "bpftool prog load -L -d file.o" command will provide additional debug messages on how syscall/loader program was generated. Also the execution of syscall/loader program will use bpf_trace_printk() for each step of loading BTF, creating maps, and loading programs. The user can do "cat /.../trace_pipe" for further debug. An example of fexit_sleep.lskel.h generated from progs/fexit_sleep.c: struct fexit_sleep { struct bpf_loader_ctx ctx; struct { struct bpf_map_desc bss; } maps; struct { struct bpf_prog_desc nanosleep_fentry; struct bpf_prog_desc nanosleep_fexit; } progs; struct { int nanosleep_fentry_fd; int nanosleep_fexit_fd; } links; struct fexit_sleep__bss { int pid; int fentry_cnt; int fexit_cnt; } *bss; }; Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210514003623.28033-18-alexei.starovoitov@gmail.com
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31332ccb |
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06-May-2021 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: Stop emitting static variables in BPF skeleton As discussed in [0], stop emitting static variables in BPF skeletons to avoid issues with name-conflicting static variables across multiple statically-linked BPF object files. Users using static variables to pass data between BPF programs and user-space should do a trivial one-time switch according to the following simple rules: - read-only `static volatile const` variables should be converted to `volatile const`; - read/write `static volatile` variables should just drop `static volatile` modifiers to become global variables/symbols. To better handle older Clang versions, such newly converted global variables should be explicitly initialized with a specific value or `= 0`/`= {}`, whichever is appropriate. [0] https://lore.kernel.org/bpf/CAEf4BzZo7_r-hsNvJt3w3kyrmmBJj7ghGY8+k4nvKF0KLjma=w@mail.gmail.com/T/#m664d4b0d6b31ac8b2669360e0fc2d6962e9f5ec1 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210507054119.270888-5-andrii@kernel.org
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fdbf5dde |
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06-May-2021 |
Andrii Nakryiko <andrii@kernel.org> |
libbpf: Add per-file linker opts 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: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210507054119.270888-3-andrii@kernel.org
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37f05601 |
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06-May-2021 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: Strip const/volatile/restrict modifiers from .bss and .data vars Similarly to .rodata, strip any const/volatile/restrict modifiers when generating BPF skeleton. They are not helpful and actually just get in the way. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210507054119.270888-2-andrii@kernel.org
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d80b2fcb |
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18-Mar-2021 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: Add `gen object` command to perform BPF static linking Add `bpftool gen object <output-file> <input_file>...` command to statically link multiple BPF ELF object files into a single output BPF ELF object file. This patch also updates bash completions and man page. Man page gets a short section on `gen object` command, but also updates the skeleton example to show off workflow for BPF application with two .bpf.c files, compiled individually with Clang, then resulting object files are linked together with `gen object`, and then final object file is used to generate usable BPF skeleton. This should help new users understand realistic workflow w.r.t. compiling mutli-file BPF application. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20210318194036.3521577-10-andrii@kernel.org
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c4122665 |
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18-Mar-2021 |
Andrii Nakryiko <andrii@kernel.org> |
bpftool: Add ability to specify custom skeleton object name Add optional name OBJECT_NAME parameter to `gen skeleton` command to override default object name, normally derived from input file name. This allows much more flexibility during build time. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210318194036.3521577-9-andrii@kernel.org
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7084566a |
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18-Aug-2020 |
Andrii Nakryiko <andriin@fb.com> |
tools/bpftool: Remove libbpf_internal.h usage in bpftool Most netlink-related functions were unique to bpftool usage, so I moved them into net.c. Few functions are still used by both bpftool and libbpf itself internally, so I've copy-pasted them (libbpf_nl_get_link, libbpf_netlink_open). It's a bit of duplication of code, but better separation of libbpf as a library with public API and bpftool, relying on unexposed functions in libbpf. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200819013607.3607269-3-andriin@fb.com
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0f993845 |
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13-Aug-2020 |
Andrii Nakryiko <andriin@fb.com> |
tools/bpftool: Generate data section struct with conservative alignment The comment in the code describes this in good details. Generate such a memory layout that would work both on 32-bit and 64-bit architectures for user-space. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200813204945.1020225-9-andriin@fb.com
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8faf7fc5 |
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11-Aug-2020 |
Andrii Nakryiko <andriin@fb.com> |
tools/bpftool: Make skeleton code C++17-friendly by dropping typeof() Seems like C++17 standard mode doesn't recognize typeof() anymore. This can be tested by compiling test_cpp test with -std=c++17 or -std=c++1z options. The use of typeof in skeleton generated code is unnecessary, all types are well-known at the time of code generation, so remove all typeof()'s to make skeleton code more future-proof when interacting with C++ compilers. Fixes: 985ead416df3 ("bpftool: Add skeleton codegen command") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200812025907.1371956-1-andriin@fb.com
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956fcfcd |
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17-Jul-2020 |
YueHaibing <yuehaibing@huawei.com> |
tools/bpftool: Fix error handing in do_skeleton() Fix pass 0 to PTR_ERR, also dump more err info using libbpf_strerror. Fixes: 5dc7a8b21144 ("bpftool, selftests/bpf: Embed object file inside skeleton") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20200717123059.29624-1-yuehaibing@huawei.com
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0b20933d |
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13-Jul-2020 |
Andrii Nakryiko <andriin@fb.com> |
tools/bpftool: Strip away modifiers from global variables Reliably remove all the type modifiers from read-only (.rodata) global variable definitions, including cases of inner field const modifiers and arrays of const values. Also modify one of selftests to ensure that const volatile struct doesn't prevent user-space from modifying .rodata variable. Fixes: 985ead416df3 ("bpftool: Add skeleton codegen command") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200713232409.3062144-3-andriin@fb.com
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22eb7879 |
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12-Jun-2020 |
Andrii Nakryiko <andriin@fb.com> |
tools/bpftool: Fix skeleton codegen Remove unnecessary check at the end of codegen() routine which makes codegen() to always fail and exit bpftool with error code. Positive value of variable n is not an indicator of a failure. Fixes: 2c4779eff837 ("tools, bpftool: Exit on error in function codegen") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Tobias Klauser <tklauser@distanz.ch> Link: https://lore.kernel.org/bpf/20200612201603.680852-1-andriin@fb.com
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2c4779ef |
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10-Jun-2020 |
Tobias Klauser <tklauser@distanz.ch> |
tools, bpftool: Exit on error in function codegen Currently, the codegen function might fail and return an error. But its callers continue without checking its return value. Since codegen can fail only in the unlikely case of the system running out of memory or the static template being malformed, just exit(-1) directly from codegen and make it void-returning. Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com> Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200611103341.21532-1-tklauser@distanz.ch
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d4060ac9 |
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10-Jun-2020 |
Tobias Klauser <tklauser@distanz.ch> |
tools, bpftool: Fix memory leak in codegen error cases Free the memory allocated for the template on error paths in function codegen. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200610130804.21423-1-tklauser@distanz.ch
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90040351 |
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22-May-2020 |
Quentin Monnet <quentin@isovalent.com> |
tools, bpftool: Clean subcommand help messages This is a clean-up for the formatting of the do_help functions for bpftool's subcommands. The following fixes are included: - Do not use argv[-2] for "iter" help message, as the help is shown by default if no "iter" action is selected, resulting in messages looking like "./bpftool bpftool pin...". - Do not print unused HELP_SPEC_PROGRAM in help message for "bpftool link". - Andrii used argument indexing to avoid having multiple occurrences of bin_name and argv[-2] in the fprintf() for the help message, for "bpftool gen" and "bpftool link". Let's reuse this for all other help functions. We can remove up to thirty arguments for the "bpftool map" help message. - Harmonise all functions, e.g. use ending quotes-comma on a separate line. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200523010751.23465-1-quentin@isovalent.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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93e51689 |
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18-Apr-2020 |
Jagadeesh Pagadala <jagdsh.linux@gmail.com> |
tools/bpf/bpftool: Remove duplicate headers Code cleanup: Remove duplicate headers which are included twice. Signed-off-by: Jagadeesh Pagadala <jagdsh.linux@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/1587274757-14101-1-git-send-email-jagdsh.linux@gmail.com
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229c3b47 |
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20-Jan-2020 |
Toke Høiland-Jørgensen <toke@redhat.com> |
bpftool: Use consistent include paths for libbpf Fix bpftool to include libbpf header files with the bpf/ prefix, to be consistent with external users of the library. Also ensure that all includes of exported libbpf header files (those that are exported on 'make install' of the library) use bracketed includes instead of quoted. To make sure no new files are introduced that doesn't include the bpf/ prefix in its include, remove tools/lib/bpf from the include path entirely, and use tools/lib instead. Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/157952560684.1683545.4765181397974997027.stgit@toke.dk
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7c8dce4b |
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26-Dec-2019 |
Andrii Nakryiko <andriin@fb.com> |
bpftool: Make skeleton C code compilable with C++ compiler When auto-generated BPF skeleton C code is included from C++ application, it triggers compilation error due to void * being implicitly casted to whatever target pointer type. This is supported by C, but not C++. To solve this problem, add explicit casts, where necessary. To ensure issues like this are captured going forward, add skeleton usage in test_cpp test. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191226210253.3132060-1-andriin@fb.com
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81bfdd08 |
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18-Dec-2019 |
Andrii Nakryiko <andriin@fb.com> |
libbpf: Put Kconfig externs into .kconfig section Move Kconfig-provided externs into custom .kconfig section. Add __kconfig into bpf_helpers.h for user convenience. Update selftests accordingly. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191219002837.3074619-2-andriin@fb.com
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7c43e0d6 |
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18-Dec-2019 |
Andrii Nakryiko <andriin@fb.com> |
bpftool: Simplify format string to not use positional args Change format string referring to just single argument out of two available. Some versions of libc can reject such format string. Reported-by: Nikita Shirokov <tehnerd@tehnerd.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20191218214314.2403729-1-andriin@fb.com
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5dc7a8b2 |
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17-Dec-2019 |
Andrii Nakryiko <andriin@fb.com> |
bpftool, selftests/bpf: Embed object file inside skeleton Embed contents of BPF object file used for BPF skeleton generation inside skeleton itself. This allows to keep BPF object file and its skeleton in sync at all times, and simpifies skeleton instantiation. Also switch existing selftests to not require BPF_EMBED_OBJ anymore. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20191218052552.2915188-2-andriin@fb.com
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159ecc00 |
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15-Dec-2019 |
Paul Chaignon <paul.chaignon@orange.com> |
bpftool: Fix compilation warning on shadowed variable The ident variable has already been declared at the top of the function and doesn't need to be re-declared. Fixes: 985ead416df39 ("bpftool: Add skeleton codegen command") Signed-off-by: Paul Chaignon <paul.chaignon@orange.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191216112733.GA28366@Omicron
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2ad97d47 |
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13-Dec-2019 |
Andrii Nakryiko <andriin@fb.com> |
bpftool: Generate externs datasec in BPF skeleton Add support for generation of mmap()-ed read-only view of libbpf-provided extern variables. As externs are not supposed to be provided by user code (that's what .data, .bss, and .rodata is for), don't mmap() it initially. Only after skeleton load is performed, map .extern contents as read-only memory. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191214014710.3449601-4-andriin@fb.com
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985ead41 |
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13-Dec-2019 |
Andrii Nakryiko <andriin@fb.com> |
bpftool: Add skeleton codegen command Add `bpftool gen skeleton` command, which takes in compiled BPF .o object file and dumps a BPF skeleton struct and related code to work with that skeleton. Skeleton itself is tailored to a specific structure of provided BPF object file, containing accessors (just plain struct fields) for every map and program, as well as dedicated space for bpf_links. If BPF program is using global variables, corresponding structure definitions of compatible memory layout are emitted as well, making it possible to initialize and subsequently read/update global variables values using simple and clear C syntax for accessing fields. This skeleton majorly improves usability of opening/loading/attaching of BPF object, as well as interacting with it throughout the lifetime of loaded BPF object. Generated skeleton struct has the following structure: struct <object-name> { /* used by libbpf's skeleton API */ struct bpf_object_skeleton *skeleton; /* bpf_object for libbpf APIs */ struct bpf_object *obj; struct { /* for every defined map in BPF object: */ struct bpf_map *<map-name>; } maps; struct { /* for every program in BPF object: */ struct bpf_program *<program-name>; } progs; struct { /* for every program in BPF object: */ struct bpf_link *<program-name>; } links; /* for every present global data section: */ struct <object-name>__<one of bss, data, or rodata> { /* memory layout of corresponding data section, * with every defined variable represented as a struct field * with exactly the same type, but without const/volatile * modifiers, e.g.: */ int *my_var_1; ... } *<one of bss, data, or rodata>; }; This provides great usability improvements: - no need to look up maps and programs by name, instead just my_obj->maps.my_map or my_obj->progs.my_prog would give necessary bpf_map/bpf_program pointers, which user can pass to existing libbpf APIs; - pre-defined places for bpf_links, which will be automatically populated for program types that libbpf knows how to attach automatically (currently tracepoints, kprobe/kretprobe, raw tracepoint and tracing programs). On tearing down skeleton, all active bpf_links will be destroyed (meaning BPF programs will be detached, if they are attached). For cases in which libbpf doesn't know how to auto-attach BPF program, user can manually create link after loading skeleton and they will be auto-detached on skeleton destruction: my_obj->links.my_fancy_prog = bpf_program__attach_cgroup_whatever( my_obj->progs.my_fancy_prog, <whatever extra param); - it's extremely easy and convenient to work with global data from userspace now. Both for read-only and read/write variables, it's possible to pre-initialize them before skeleton is loaded: skel = my_obj__open(raw_embed_data); my_obj->rodata->my_var = 123; my_obj__load(skel); /* 123 will be initialization value for my_var */ After load, if kernel supports mmap() for BPF arrays, user can still read (and write for .bss and .data) variables values, but at that point it will be directly mmap()-ed to BPF array, backing global variables. This allows to seamlessly exchange data with BPF side. From userspace program's POV, all the pointers and memory contents stay the same, but mapped kernel memory changes to point to created map. If kernel doesn't yet support mmap() for BPF arrays, it's still possible to use those data section structs to pre-initialize .bss, .data, and .rodata, but after load their pointers will be reset to NULL, allowing user code to gracefully handle this condition, if necessary. 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/20191214014341.3442258-14-andriin@fb.com
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