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2022-06-28libbpf: remove deprecated BTF APIsAndrii Nakryiko1-182/+1
Get rid of deprecated BTF-related APIs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220627211527.2245459-6-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-07libbpf: Add enum64 deduplication supportYonghong Song1-2/+60
Add enum64 deduplication support. BTF_KIND_ENUM64 handling is very similar to BTF_KIND_ENUM. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220607062626.3720166-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-07libbpf: Add enum64 parsing and new enum64 public APIYonghong Song1-0/+103
Add enum64 parsing support and two new enum64 public APIs: btf__add_enum64 btf__add_enum64_value Also add support of signedness for BTF_KIND_ENUM. The BTF_KIND_ENUM API signatures are not changed. The signedness will be changed from unsigned to signed if btf__add_enum_value() finds any negative values. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220607062621.3719391-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-07libbpf: Refactor btf__add_enum() for future code sharingYonghong Song1-15/+21
Refactor btf__add_enum() function to create a separate function btf_add_enum_common() so later the common function can be used to add enum64 btf type. There is no functionality change for this patch. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220607062615.3718063-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-03libbpf: Fix a couple of typosDaniel Müller1-1/+1
This change fixes a couple of typos that were encountered while studying the source code. Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20220601154025.3295035-1-deso@posteo.net
2022-06-02libbpf: Fix determine_ptr_size() guessingDouglas Raillard1-6/+20
One strategy employed by libbpf to guess the pointer size is by finding the size of "unsigned long" type. This is achieved by looking for a type of with the expected name and checking its size. Unfortunately, the C syntax is friendlier to humans than to computers as there is some variety in how such a type can be named. Specifically, gcc and clang do not use the same names for integer types in debug info: - clang uses "unsigned long" - gcc uses "long unsigned int" Lookup all the names for such a type so that libbpf can hope to find the information it wants. Signed-off-by: Douglas Raillard <douglas.raillard@arm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20220524094447.332186-1-douglas.raillard@arm.com
2022-04-26libbpf: Avoid joining .BTF.ext data with BPF programs by section nameAndrii Nakryiko1-2/+7
Instead of using ELF section names as a joining key between .BTF.ext and corresponding BPF programs, pre-build .BTF.ext section number to ELF section index mapping during bpf_object__open() and use it later for matching .BTF.ext information (func/line info or CO-RE relocations) to their respective BPF programs and subprograms. This simplifies corresponding joining logic and let's libbpf do manipulations with BPF program's ELF sections like dropping leading '?' character for non-autoloaded programs. Original joining logic in bpf_object__relocate_core() (see relevant comment that's now removed) was never elegant, so it's a good improvement regardless. But it also avoids unnecessary internal assumptions about preserving original ELF section name as BPF program's section name (which was broken when SEC("?abc") support was added). Fixes: a3820c481112 ("libbpf: Support opting out from autoloading BPF programs declaratively") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220426004511.2691730-5-andrii@kernel.org
2022-04-03libbpf: Don't return -EINVAL if hdr_len < offsetofend(core_relo_len)Yuntao Wang1-4/+2
Since core relos is an optional part of the .BTF.ext ELF section, we should skip parsing it instead of returning -EINVAL if header size is less than offsetofend(struct btf_ext_header, core_relo_len). Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220404005320.1723055-1-ytcoode@gmail.com
2022-01-19libbpf: Improve btf__add_btf() with an additional hashmap for strings.Kui-Feng Lee1-1/+30
Add a hashmap to map the string offsets from a source btf to the string offsets from a target btf to reduce overheads. btf__add_btf() calls btf__add_str() to add strings from a source to a target btf. It causes many string comparisons, and it is a major hotspot when adding a big btf. btf__add_str() uses strcmp() to check if a hash entry is the right one. The extra hashmap here compares offsets of strings, that are much cheaper. It remembers the results of btf__add_str() for later uses to reduce the cost. We are parallelizing BTF encoding for pahole by creating separated btf instances for worker threads. These per-thread btf instances will be added to the btf instance of the main thread by calling btf__add_str() to deduplicate and write out. With this patch and -j4, the running time of pahole drops to about 6.0s from 6.6s. The following lines are the summary of 'perf stat' w/o the change. 6.668126396 seconds time elapsed 13.451054000 seconds user 0.715520000 seconds sys The following lines are the summary w/ the change. 5.986973919 seconds time elapsed 12.939903000 seconds user 0.724152000 seconds sys V4 fixes a bug of error checking against the pointer returned by hashmap__new(). [v3] https://lore.kernel.org/bpf/20220118232053.2113139-1-kuifeng@fb.com/ [v2] https://lore.kernel.org/bpf/20220114193713.461349-1-kuifeng@fb.com/ Signed-off-by: Kui-Feng Lee <kuifeng@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220119180214.255634-1-kuifeng@fb.com
2021-12-10libbpf: Fix typo in btf__dedup@LIBBPF_0.0.2 definitionVincent Minet1-1/+1
The btf__dedup_deprecated name was misspelled in the definition of the compat symbol for btf__dedup. This leads it to be missing from the shared library. This fixes it. Fixes: 957d350a8b94 ("libbpf: Turn btf_dedup_opts into OPTS-based struct") Signed-off-by: Vincent Minet <vincent@vincent-minet.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211210063112.80047-1-vincent@vincent-minet.net
2021-12-10libbpf: Allow passing preallocated log_buf when loading BTF into kernelAndrii Nakryiko1-23/+55
Add libbpf-internal btf_load_into_kernel() that allows to pass preallocated log_buf and custom log_level to be passed into kernel during BPF_BTF_LOAD call. When custom log_buf is provided, btf_load_into_kernel() won't attempt an retry with automatically allocated internal temporary buffer to capture BTF validation log. It's important to note the relation between log_buf and log_level, which slightly deviates from stricter kernel logic. From kernel's POV, if log_buf is specified, log_level has to be > 0, and vice versa. While kernel has good reasons to request such "sanity, this, in practice, is a bit unconvenient and restrictive for libbpf's high-level bpf_object APIs. So libbpf will allow to set non-NULL log_buf and log_level == 0. This is fine and means to attempt to load BTF without logging requested, but if it failes, retry the load with custom log_buf and log_level 1. Similar logic will be implemented for program loading. In practice this means that users can provide custom log buffer just in case error happens, but not really request slower verbose logging all the time. This is also consistent with libbpf behavior when custom log_buf is not set: libbpf first tries to load everything with log_level=0, and only if error happens allocates internal log buffer and retries with log_level=1. Also, while at it, make BTF validation log more obvious and follow the log pattern libbpf is using for dumping BPF verifier log during BPF_PROG_LOAD. BTF loading resulting in an error will look like this: libbpf: BTF loading error: -22 libbpf: -- BEGIN BTF LOAD LOG --- magic: 0xeb9f version: 1 flags: 0x0 hdr_len: 24 type_off: 0 type_len: 1040 str_off: 1040 str_len: 2063598257 btf_total_size: 1753 Total section length too long -- END BTF LOAD LOG -- libbpf: Error loading .BTF into kernel: -22. BTF is optional, ignoring. This makes it much easier to find relevant parts in libbpf log output. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211209193840.1248570-4-andrii@kernel.org
2021-12-02libbpf: Replace btf__type_by_id() with btf_type_by_id().Alexei Starovoitov1-1/+1
To prepare relo_core.c to be compiled in the kernel and the user space replace btf__type_by_id with btf_type_by_id. In libbpf btf__type_by_id and btf_type_by_id have different behavior. bpf_core_apply_relo_insn() needs behavior of uapi btf__type_by_id vs internal btf_type_by_id, but type_id range check is already done in bpf_core_apply_relo(), so it's safe to replace it everywhere. The kernel btf_type_by_id() does the check anyway. It doesn't hurt. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-2-alexei.starovoitov@gmail.com
2021-11-26libbpf: Fix potential misaligned memory access in btf_ext__new()Andrii Nakryiko1-5/+5
Perform a memory copy before we do the sanity checks of btf_ext_hdr. This prevents misaligned memory access if raw btf_ext data is not 4-byte aligned ([0]). While at it, also add missing const qualifier. [0] Closes: https://github.com/libbpf/libbpf/issues/391 Fixes: 2993e0515bb4 ("tools/bpf: add support to read .BTF.ext sections") Reported-by: Evgeny Vereshchagin <evvers@ya.ru> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211124002325.1737739-3-andrii@kernel.org
2021-11-19libbpf: Accommodate DWARF/compiler bug with duplicated structsAndrii Nakryiko1-4/+41
According to [0], compilers sometimes might produce duplicate DWARF definitions for exactly the same struct/union within the same compilation unit (CU). We've had similar issues with identical arrays and handled them with a similar workaround in 6b6e6b1d09aa ("libbpf: Accomodate DWARF/compiler bug with duplicated identical arrays"). Do the same for struct/union by ensuring that two structs/unions are exactly the same, down to the integer values of field referenced type IDs. Solving this more generically (allowing referenced types to be equivalent, but using different type IDs, all within a single CU) requires a huge complexity increase to handle many-to-many mappings between canonidal and candidate type graphs. Before we invest in that, let's see if this approach handles all the instances of this issue in practice. Thankfully it's pretty rare, it seems. [0] https://lore.kernel.org/bpf/YXr2NFlJTAhHdZqq@krava/ Reported-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211117194114.347675-1-andrii@kernel.org
2021-11-16libbpf: Fix a couple of missed btf_type_tag handling in btf.cYonghong Song1-0/+2
Commit 2dc1e488e5cd ("libbpf: Support BTF_KIND_TYPE_TAG") added the BTF_KIND_TYPE_TAG support. But to test vmlinux build with ... #define __user __attribute__((btf_type_tag("user"))) ... I needed to sync libbpf repo and manually copy libbpf sources to pahole. To simplify process, I used BTF_KIND_RESTRICT to simulate the BTF_KIND_TYPE_TAG with vmlinux build as "restrict" modifier is barely used in kernel. But this approach missed one case in dedup with structures where BTF_KIND_RESTRICT is handled and BTF_KIND_TYPE_TAG is not handled in btf_dedup_is_equiv(), and this will result in a pahole dedup failure. This patch fixed this issue and a selftest is added in the subsequent patch to test this scenario. The other missed handling is in btf__resolve_size(). Currently the compiler always emit like PTR->TYPE_TAG->... so in practice we don't hit the missing BTF_KIND_TYPE_TAG handling issue with compiler generated code. But lets add case BTF_KIND_TYPE_TAG in the switch statement to be future proof. Fixes: 2dc1e488e5cd ("libbpf: Support BTF_KIND_TYPE_TAG") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211115163937.3922235-1-yhs@fb.com
2021-11-11libbpf: Support BTF_KIND_TYPE_TAGYonghong Song1-0/+23
Add libbpf support for BTF_KIND_TYPE_TAG. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211112012614.1505315-1-yhs@fb.com
2021-11-11libbpf: Turn btf_dedup_opts into OPTS-based structAndrii Nakryiko1-19/+27
btf__dedup() and struct btf_dedup_opts were added before we figured out OPTS mechanism. As such, btf_dedup_opts is non-extensible without breaking an ABI and potentially crashing user application. Unfortunately, btf__dedup() and btf_dedup_opts are short and succinct names that would be great to preserve and use going forward. So we use ___libbpf_override() macro approach, used previously for bpf_prog_load() API, to define a new btf__dedup() variant that accepts only struct btf * and struct btf_dedup_opts * arguments, and rename the old btf__dedup() implementation into btf__dedup_deprecated(). This keeps both source and binary compatibility with old and new applications. The biggest problem was struct btf_dedup_opts, which wasn't OPTS-based, and as such doesn't have `size_t sz;` as a first field. But btf__dedup() is a pretty rarely used API and I believe that the only currently known users (besides selftests) are libbpf's own bpf_linker and pahole. Neither use case actually uses options and just passes NULL. So instead of doing extra hacks, just rewrite struct btf_dedup_opts into OPTS-based one, move btf_ext argument into those opts (only bpf_linker needs to dedup btf_ext, so it's not a typical thing to specify), and drop never used `dont_resolve_fwds` option (it was never used anywhere, AFAIK, it makes BTF dedup much less useful and efficient). Just in case, for old implementation, btf__dedup_deprecated(), detect non-NULL options and error out with helpful message, to help users migrate, if there are any user playing with btf__dedup(). The last remaining piece is dedup_table_size, which is another anachronism from very early days of BTF dedup. Since then it has been reduced to the only valid value, 1, to request forced hash collisions. This is only used during testing. So instead introduce a bool flag to force collisions explicitly. This patch also adapts selftests to new btf__dedup() and btf_dedup_opts use to avoid selftests breakage. [0] Closes: https://github.com/libbpf/libbpf/issues/281 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211111053624.190580-4-andrii@kernel.org
2021-10-28libbpf: Use O_CLOEXEC uniformly when opening fdsKumar Kartikeya Dwivedi1-1/+1
There are some instances where we don't use O_CLOEXEC when opening an fd, fix these up. Otherwise, it is possible that a parallel fork causes these fds to leak into a child process on execve. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211028063501.2239335-6-memxor@gmail.com
2021-10-25libbpf: Use __BYTE_ORDER__Ilya Leoshkevich1-2/+2
Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined __BYTE_ORDER for consistency. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211026010831.748682-3-iii@linux.ibm.com
2021-10-22libbpf: Fix BTF header parsing checksAndrii Nakryiko1-3/+9
Original code assumed fixed and correct BTF header length. That's not always the case, though, so fix this bug with a proper additional check. And use actual header length instead of sizeof(struct btf_header) in sanity checks. Fixes: 8a138aed4a80 ("bpf: btf: Add BTF support to libbpf") Reported-by: Evgeny Vereshchagin <evvers@ya.ru> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211023003157.726961-2-andrii@kernel.org
2021-10-22libbpf: Fix overflow in BTF sanity checksAndrii Nakryiko1-2/+2
btf_header's str_off+str_len or type_off+type_len can overflow as they are u32s. This will lead to bypassing the sanity checks during BTF parsing, resulting in crashes afterwards. Fix by using 64-bit signed integers for comparison. Fixes: d8123624506c ("libbpf: Fix BTF data layout checks and allow empty BTF") Reported-by: Evgeny Vereshchagin <evvers@ya.ru> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211023003157.726961-1-andrii@kernel.org
2021-10-22libbpf: Add btf__type_cnt() and btf__raw_data() APIsHengqi Chen1-14/+22
Add btf__type_cnt() and btf__raw_data() APIs and deprecate btf__get_nr_type() and btf__get_raw_data() since the old APIs don't follow the libbpf naming convention for getters which omit 'get' in the name (see [0]). btf__raw_data() is just an alias to the existing btf__get_raw_data(). btf__type_cnt() now returns the number of all types of the BTF object including 'void'. [0] Closes: https://github.com/libbpf/libbpf/issues/279 Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211022130623.1548429-2-hengqi.chen@gmail.com
2021-10-22libbpf: Fix memory leak in btf__dedup()Mauricio Vásquez1-2/+4
Free btf_dedup if btf_ensure_modifiable() returns error. Fixes: 919d2b1dbb07 ("libbpf: Allow modification of BTF and add btf__add_str API") Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211022202035.48868-1-mauricio@kinvolk.io
2021-10-21libbpf: Deprecate btf__finalize_data() and move it into libbpf.cAndrii Nakryiko1-93/+0
There isn't a good use case where anyone but libbpf itself needs to call btf__finalize_data(). It was implemented for internal use and it's not clear why it was made into public API in the first place. To function, it requires active ELF data, which is stored inside bpf_object for the duration of opening phase only. But the only BTF that needs bpf_object's ELF is that bpf_object's BTF itself, which libbpf fixes up automatically during bpf_object__open() operation anyways. There is no need for any additional fix up and no reasonable scenario where it's useful and appropriate. Thus, btf__finalize_data() is just an API atavism and is better removed. So this patch marks it as deprecated immediately (v0.6+) and moves the code from btf.c into libbpf.c where it's used in the context of bpf_object opening phase. Such code co-location allows to make code structure more straightforward and remove bpf_object__section_size() and bpf_object__variable_offset() internal helpers from libbpf_internal.h, making them static. Their naming is also adjusted to not create a wrong illusion that they are some sort of method of bpf_object. They are internal helpers and are called appropriately. This is part of libbpf 1.0 effort ([0]). [0] Closes: https://github.com/libbpf/libbpf/issues/276 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/20211021014404.2635234-2-andrii@kernel.org
2021-10-18bpf: Rename BTF_KIND_TAG to BTF_KIND_DECL_TAGYonghong Song1-18/+18
Patch set [1] introduced BTF_KIND_TAG to allow tagging declarations for struct/union, struct/union field, var, func and func arguments and these tags will be encoded into dwarf. They are also encoded to btf by llvm for the bpf target. After BTF_KIND_TAG is introduced, we intended to use it for kernel __user attributes. But kernel __user is actually a type attribute. Upstream and internal discussion showed it is not a good idea to mix declaration attribute and type attribute. So we proposed to introduce btf_type_tag as a type attribute and existing btf_tag renamed to btf_decl_tag ([2]). This patch renamed BTF_KIND_TAG to BTF_KIND_DECL_TAG and some other declarations with *_tag to *_decl_tag to make it clear the tag is for declaration. In the future, BTF_KIND_TYPE_TAG might be introduced per [3]. [1] https://lore.kernel.org/bpf/20210914223004.244411-1-yhs@fb.com/ [2] https://reviews.llvm.org/D111588 [3] https://reviews.llvm.org/D111199 Fixes: b5ea834dde6b ("bpf: Support for new btf kind BTF_KIND_TAG") Fixes: 5b84bd10363e ("libbpf: Add support for BTF_KIND_TAG") Fixes: 5c07f2fec003 ("bpftool: Add support for BTF_KIND_TAG") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211012164838.3345699-1-yhs@fb.com
2021-10-06libbpf: Add API that copies all BTF types from one BTF object to anotherAndrii Nakryiko1-2/+112
Add a bulk copying api, btf__add_btf(), that speeds up and simplifies appending entire contents of one BTF object to another one, taking care of copying BTF type data, adjusting resulting BTF type IDs according to their new locations in the destination BTF object, as well as copying and deduplicating all the referenced strings and updating all the string offsets in new BTF types as appropriate. This API is intended to be used from tools that are generating and otherwise manipulating BTFs generically, such as pahole. In pahole's case, this API is useful for speeding up parallelized BTF encoding, as it allows pahole to offload all the intricacies of BTF type copying to libbpf and handle the parallelization aspects of the process. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Link: https://lore.kernel.org/bpf/20211006051107.17921-2-andrii@kernel.org
2021-10-05libbpf: Support kernel module function callsKumar Kartikeya Dwivedi1-3/+15
This patch adds libbpf support for kernel module function call support. The fd_array parameter is used during BPF program load to pass module BTFs referenced by the program. insn->off is set to index into this array, but starts from 1, because insn->off as 0 is reserved for btf_vmlinux. We try to use existing insn->off for a module, since the kernel limits the maximum distinct module BTFs for kfuncs to 256, and also because index must never exceed the maximum allowed value that can fit in insn->off (INT16_MAX). In the future, if kernel interprets signed offset as unsigned for kfunc calls, this limit can be increased to UINT16_MAX. Also introduce a btf__find_by_name_kind_own helper to start searching from module BTF's start id when we know that the BTF ID is not present in vmlinux BTF (in find_ksym_btf_id). Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211002011757.311265-7-memxor@gmail.com
2021-09-14libbpf: Add support for BTF_KIND_TAGYonghong Song1-0/+68
Add BTF_KIND_TAG support for parsing and dedup. Also added sanitization for BTF_KIND_TAG. If BTF_KIND_TAG is not supported in the kernel, sanitize it to INTs. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210914223025.246687-1-yhs@fb.com
2021-09-14libbpf: Rename btf_{hash,equal}_int to btf_{hash,equal}_int_tagYonghong Song1-8/+8
This patch renames functions btf_{hash,equal}_int() to btf_{hash,equal}_int_tag() so they can be reused for BTF_KIND_TAG support. There is no functionality change for this patch. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210914223020.245829-1-yhs@fb.com
2021-08-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-2/+1
Conflicts: drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h 9e26680733d5 ("bnxt_en: Update firmware call to retrieve TX PTP timestamp") 9e518f25802c ("bnxt_en: 1PPS functions to configure TSIO pins") 099fdeda659d ("bnxt_en: Event handler for PPS events") kernel/bpf/helpers.c include/linux/bpf-cgroup.h a2baf4e8bb0f ("bpf: Fix potentially incorrect results with bpf_get_local_storage()") c7603cfa04e7 ("bpf: Add ambient BPF runtime context stored in current") drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c 5957cc557dc5 ("net/mlx5: Set all field of mlx5_irq before inserting it to the xarray") 2d0b41a37679 ("net/mlx5: Refcount mlx5_irq with integer") MAINTAINERS 7b637cd52f02 ("MAINTAINERS: fix Microchip CAN BUS Analyzer Tool entry typo") 7d901a1e878a ("net: phy: add Maxlinear GPY115/21x/24x driver") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-07libbpf: Do not close un-owned FD 0 on errorsDaniel Xu1-2/+1
Before this patch, btf_new() was liable to close an arbitrary FD 0 if BTF parsing failed. This was because: * btf->fd was initialized to 0 through the calloc() * btf__free() (in the `done` label) closed any FDs >= 0 * btf->fd is left at 0 if parsing fails This issue was discovered on a system using libbpf v0.3 (without BTF_KIND_FLOAT support) but with a kernel that had BTF_KIND_FLOAT types in BTF. Thus, parsing fails. While this patch technically doesn't fix any issues b/c upstream libbpf has BTF_KIND_FLOAT support, it'll help prevent issues in the future if more BTF types are added. It also allow the fix to be backported to older libbpf's. Fixes: 3289959b97ca ("libbpf: Support BTF loading and raw data output in both endianness") Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/5969bb991adedb03c6ae93e051fd2a00d293cf25.1627513670.git.dxu@dxuuu.xyz
2021-07-30libbpf: Add btf__load_vmlinux_btf/btf__load_module_btfHengqi Chen1-2/+12
Add two new APIs: btf__load_vmlinux_btf and btf__load_module_btf. btf__load_vmlinux_btf is just an alias to the existing API named libbpf_find_kernel_btf, rename to be more precisely and consistent with existing BTF APIs. btf__load_module_btf can be used to load module BTF, add it for completeness. These two APIs are useful for implementing tracing tools and introspection tools. This is part of the effort towards libbpf 1.0 ([0]). [0] Closes: https://github.com/libbpf/libbpf/issues/280 Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210730114012.494408-1-hengqi.chen@gmail.com
2021-07-29libbpf: Add split BTF support for btf__load_from_kernel_by_id()Quentin Monnet1-2/+7
Add a new API function btf__load_from_kernel_by_id_split(), which takes a pointer to a base BTF object in order to support split BTF objects when retrieving BTF information from the kernel. Reference: https://github.com/libbpf/libbpf/issues/314 Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210729162028.29512-8-quentin@isovalent.com
2021-07-29libbpf: Rename btf__get_from_id() as btf__load_from_kernel_by_id()Quentin Monnet1-8/+17
Rename function btf__get_from_id() as btf__load_from_kernel_by_id() to better indicate what the function does. Change the new function so that, instead of requiring a pointer to the pointer to update and returning with an error code, it takes a single argument (the id of the BTF object) and returns the corresponding pointer. This is more in line with the existing constructors. The other tools calling the (soon-to-be) deprecated btf__get_from_id() function will be updated in a future commit. References: - https://github.com/libbpf/libbpf/issues/278 - https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#btfh-apis Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210729162028.29512-4-quentin@isovalent.com
2021-07-29libbpf: Rename btf__load() as btf__load_into_kernel()Quentin Monnet1-1/+2
As part of the effort to move towards a v1.0 for libbpf, rename btf__load() function, used to "upload" BTF information into the kernel, as btf__load_into_kernel(). This new name better reflects what the function does. References: - https://github.com/libbpf/libbpf/issues/278 - https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#btfh-apis Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210729162028.29512-3-quentin@isovalent.com
2021-05-25libbpf: Streamline error reporting for high-level APIsAndrii Nakryiko1-150/+152
Implement changes to error reporting for high-level libbpf APIs to make them less surprising and less error-prone to users: - in all the cases when error happens, errno is set to an appropriate error value; - in libbpf 1.0 mode, all pointer-returning APIs return NULL on error and error code is communicated through errno; this applies both to APIs that already returned NULL before (so now they communicate more detailed error codes), as well as for many APIs that used ERR_PTR() macro and encoded error numbers as fake pointers. - in legacy (default) mode, those APIs that were returning ERR_PTR(err), continue doing so, but still set errno. With these changes, errno can be always used to extract actual error, regardless of legacy or libbpf 1.0 modes. This is utilized internally in libbpf in places where libbpf uses it's own high-level APIs. libbpf_get_error() is adapted to handle both cases completely transparently to end-users (and is used by libbpf consistently as well). More context, justification, and discussion can be found in "Libbpf: the road to v1.0" document ([0]). [0] https://docs.google.com/document/d/1UyjTZuPFWiPFyKk1tV5an11_iaRuec6U-ZESZ54nNTY 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/20210525035935.1461796-5-andrii@kernel.org
2021-04-23libbpf: Mark BPF subprogs with hidden visibility as static for BPF verifierAndrii Nakryiko1-5/+0
Define __hidden helper macro in bpf_helpers.h, which is a short-hand for __attribute__((visibility("hidden"))). Add libbpf support to mark BPF subprograms marked with __hidden as static in BTF information to enforce BPF verifier's static function validation algorithm, which takes more information (caller's context) into account during a subprogram validation. 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/20210423181348.1801389-5-andrii@kernel.org
2021-03-18libbpf: Add generic BTF type shallow copy APIAndrii Nakryiko1-0/+48
Add btf__add_type() API that performs shallow copy of a given BTF type from the source BTF into the destination BTF. All the information and type IDs are preserved, but all the strings encountered are added into the destination BTF and corresponding offsets are rewritten. BTF type IDs are assumed to be correct or such that will be (somehow) modified afterwards. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210318194036.3521577-6-andrii@kernel.org
2021-03-18libbpf: Extract internal set-of-strings datastructure APIsAndrii Nakryiko1-194/+61
Extract BTF logic for maintaining a set of strings data structure, used for BTF strings section construction in writable mode, into separate re-usable API. This data structure is going to be used by bpf_linker to maintains ELF STRTAB section, which has the same layout as BTF strings section. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210318194036.3521577-5-andrii@kernel.org
2021-03-18libbpf: Rename internal memory-management helpersAndrii Nakryiko1-12/+12
Rename btf_add_mem() and btf_ensure_mem() helpers that abstract away details of dynamically resizable memory to use libbpf_ prefix, as they are not BTF-specific. No functional changes. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210318194036.3521577-4-andrii@kernel.org
2021-03-18libbpf: Generalize BTF and BTF.ext type ID and strings iterationAndrii Nakryiko1-172/+221
Extract and generalize the logic to iterate BTF type ID and string offset fields within BTF types and .BTF.ext data. Expose this internally in libbpf for re-use by bpf_linker. Additionally, complete strings deduplication handling for BTF.ext (e.g., CO-RE access strings), which was previously missing. There previously was no case of deduplicating .BTF.ext data, but bpf_linker is going to use it. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210318194036.3521577-3-andrii@kernel.org
2021-03-18libbpf: Expose btf_type_by_id() internallyAndrii Nakryiko1-1/+1
btf_type_by_id() is internal-only convenience API returning non-const pointer to struct btf_type. Expose it outside of btf.c for re-use. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210318194036.3521577-2-andrii@kernel.org
2021-03-04libbpf: Add BTF_KIND_FLOAT supportIlya Leoshkevich1-0/+49
The logic follows that of BTF_KIND_INT most of the time. Sanitization replaces BTF_KIND_FLOATs with equally-sized empty BTF_KIND_STRUCTs on older kernels, for example, the following: [4] FLOAT 'float' size=4 becomes the following: [4] STRUCT '(anon)' size=4 vlen=0 With dwarves patch [1] and this patch, the older kernels, which were failing with the floating-point-related errors, will now start working correctly. [1] https://github.com/iii-i/dwarves/commit/btf-kind-float-v2 Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210226202256.116518-4-iii@linux.ibm.com
2021-03-04libbpf: Fix whitespace in btf_add_composite() commentIlya Leoshkevich1-1/+1
Remove trailing space. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210226202256.116518-3-iii@linux.ibm.com
2021-01-21libbpf: Use string table index from index table if neededJiri Olsa1-2/+10
For very large ELF objects (with many sections), we could get special value SHN_XINDEX (65535) for elf object's string table index - e_shstrndx. Call elf_getshdrstrndx to get the proper string table index, instead of reading it directly from ELF header. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210121202203.9346-4-jolsa@kernel.org
2021-01-12libbpf: Allow loading empty BTFsAndrii Nakryiko1-5/+0
Empty BTFs do come up (e.g., simple kernel modules with no new types and strings, compared to the vmlinux BTF) and there is nothing technically wrong with them. So remove unnecessary check preventing loading empty BTFs. Fixes: d8123624506c ("libbpf: Fix BTF data layout checks and allow empty BTF") Reported-by: Christopher William Snowhill <chris@kode54.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210110070341.1380086-2-andrii@kernel.org
2020-12-03libbpf: Add internal helper to load BTF data by FDAndrii Nakryiko1-26/+35
Add a btf_get_from_fd() helper, which constructs struct btf from in-kernel BTF data by FD. This is used for loading module BTFs. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201203204634.1325171-4-andrii@kernel.org
2020-12-03libbpf: Add base BTF accessorAndrii Nakryiko1-0/+5
Add ability to get base BTF. It can be also used to check if BTF is split BTF. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201202065244.530571-3-andrii@kernel.org
2020-11-16libbpf: bpf__find_by_name[_kind] should use btf__get_nr_types()Alan Maguire1-4/+4
When operating on split BTF, btf__find_by_name[_kind] will not iterate over all types since they use btf->nr_types to show the number of types to iterate over. For split BTF this is the number of types _on top of base BTF_, so it will underestimate the number of types to iterate over, especially for vmlinux + module BTF, where the latter is much smaller. Use btf__get_nr_types() instead. Fixes: ba451366bf44 ("libbpf: Implement basic split BTF support") Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1605437195-2175-1-git-send-email-alan.maguire@oracle.com
2020-11-05libbpf: Accomodate DWARF/compiler bug with duplicated identical arraysAndrii Nakryiko1-2/+25
In some cases compiler seems to generate distinct DWARF types for identical arrays within the same CU. That seems like a bug, but it's already out there and breaks type graph equivalence checks, so accommodate it anyway by checking for identical arrays, regardless of their type ID. 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/20201105043402.2530976-10-andrii@kernel.org
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 19:41:01 +0000