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2021-12-28libbpf: Normalize PT_REGS_xxx() macro definitionsAndrii Nakryiko
Refactor PT_REGS macros definitions in bpf_tracing.h to avoid excessive duplication. We currently have classic PT_REGS_xxx() and CO-RE-enabled PT_REGS_xxx_CORE(). We are about to add also _SYSCALL variants, which would require excessive copying of all the per-architecture definitions. Instead, separate architecture-specific field/register names from the final macro that utilize them. That way for upcoming _SYSCALL variants we'll be able to just define x86_64 exception and otherwise have one common set of _SYSCALL macro definitions common for all architectures. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/bpf/20211222213924.1869758-1-andrii@kernel.org
2021-12-23libbpf: Do not use btf_dump__new() macro in C++ modeJiri Olsa
As reported in here [0], C++ compilers don't support __builtin_types_compatible_p(), so at least don't screw up compilation for them and let C++ users pick btf_dump__new vs btf_dump__new_deprecated explicitly. [0] https://github.com/libbpf/libbpf/issues/283#issuecomment-986100727 Fixes: 6084f5dc928f ("libbpf: Ensure btf_dump__new() and btf_dump_opts are future-proof") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20211223131736.483956-1-jolsa@kernel.org
2021-12-17libbpf: Rework feature-probing APIsAndrii Nakryiko
Create three extensible alternatives to inconsistently named feature-probing APIs: - libbpf_probe_bpf_prog_type() instead of bpf_probe_prog_type(); - libbpf_probe_bpf_map_type() instead of bpf_probe_map_type(); - libbpf_probe_bpf_helper() instead of bpf_probe_helper(). Set up return values such that libbpf can report errors (e.g., if some combination of input arguments isn't possible to validate, etc), in addition to whether the feature is supported (return value 1) or not supported (return value 0). Also schedule deprecation of those three APIs. Also schedule deprecation of bpf_probe_large_insn_limit(). Also fix all the existing detection logic for various program and map types that never worked: - BPF_PROG_TYPE_LIRC_MODE2; - BPF_PROG_TYPE_TRACING; - BPF_PROG_TYPE_LSM; - BPF_PROG_TYPE_EXT; - BPF_PROG_TYPE_SYSCALL; - BPF_PROG_TYPE_STRUCT_OPS; - BPF_MAP_TYPE_STRUCT_OPS; - BPF_MAP_TYPE_BLOOM_FILTER. Above prog/map types needed special setups and detection logic to work. Subsequent patch adds selftests that will make sure that all the detection logic keeps working for all current and future program and map types, avoiding otherwise inevitable bit rot. [0] Closes: https://github.com/libbpf/libbpf/issues/312 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Cc: Julia Kartseva <hex@fb.com> Link: https://lore.kernel.org/bpf/20211217171202.3352835-2-andrii@kernel.org
2021-12-16tools/libbpf: Enable cross-building with clangJean-Philippe Brucker
Cross-building using clang requires passing the "-target" flag rather than using the CROSS_COMPILE prefix. Makefile.include transforms CROSS_COMPILE into CLANG_CROSS_FLAGS. Add them to the CFLAGS. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20211216163842.829836-4-jean-philippe@linaro.org
2021-12-16libperf tests: Fix a spelling mistake "Runnnig" -> "Running"Colin Ian King
There is a spelling mistake in a __T_VERBOSE message. Fix it. Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: kernel-janitors@vger.kernel.org Link: http://lore.kernel.org/lkml/20211212222122.478537-1-colin.i.king@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-12-14libbpf: Avoid reading past ELF data section end when copying licenseAndrii Nakryiko
Fix possible read beyond ELF "license" data section if the license string is not properly zero-terminated. Use the fact that libbpf_strlcpy never accesses the (N-1)st byte of the source string because it's replaced with '\0' anyways. If this happens, it's a violation of contract between libbpf and a user, but not handling this more robustly upsets CIFuzz, so given the fix is trivial, let's fix the potential issue. Fixes: 9fc205b413b3 ("libbpf: Add sane strncpy alternative and use it internally") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211214232054.3458774-1-andrii@kernel.org
2021-12-14libbpf: Mark bpf_object__find_program_by_title API deprecated.Kui-Feng Lee
Deprecate this API since v0.7. All callers should move to bpf_object__find_program_by_name if possible, otherwise use bpf_object__for_each_program to find a program out from a given section. [0] Closes: https://github.com/libbpf/libbpf/issues/292 Signed-off-by: Kui-Feng Lee <kuifeng@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211214035931.1148209-5-kuifeng@fb.com
2021-12-14libbpf: Auto-bump RLIMIT_MEMLOCK if kernel needs it for BPFAndrii Nakryiko
The need to increase RLIMIT_MEMLOCK to do anything useful with BPF is one of the first extremely frustrating gotchas that all new BPF users go through and in some cases have to learn it a very hard way. Luckily, starting with upstream Linux kernel version 5.11, BPF subsystem dropped the dependency on memlock and uses memcg-based memory accounting instead. Unfortunately, detecting memcg-based BPF memory accounting is far from trivial (as can be evidenced by this patch), so in practice most BPF applications still do unconditional RLIMIT_MEMLOCK increase. As we move towards libbpf 1.0, it would be good to allow users to forget about RLIMIT_MEMLOCK vs memcg and let libbpf do the sensible adjustment automatically. This patch paves the way forward in this matter. Libbpf will do feature detection of memcg-based accounting, and if detected, will do nothing. But if the kernel is too old, just like BCC, libbpf will automatically increase RLIMIT_MEMLOCK on behalf of user application ([0]). As this is technically a breaking change, during the transition period applications have to opt into libbpf 1.0 mode by setting LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK bit when calling libbpf_set_strict_mode(). Libbpf allows to control the exact amount of set RLIMIT_MEMLOCK limit with libbpf_set_memlock_rlim_max() API. Passing 0 will make libbpf do nothing with RLIMIT_MEMLOCK. libbpf_set_memlock_rlim_max() has to be called before the first bpf_prog_load(), bpf_btf_load(), or bpf_object__load() call, otherwise it has no effect and will return -EBUSY. [0] Closes: https://github.com/libbpf/libbpf/issues/369 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211214195904.1785155-2-andrii@kernel.org
2021-12-14libbpf: Add sane strncpy alternative and use it internallyAndrii Nakryiko
strncpy() has a notoriously error-prone semantics which makes GCC complain about it a lot (and quite often completely completely falsely at that). Instead of pleasing GCC all the time (-Wno-stringop-truncation is unfortunately only supported by GCC, so it's a bit too messy to just enable it in Makefile), add libbpf-internal libbpf_strlcpy() helper which follows what FreeBSD's strlcpy() does and what most people would expect from strncpy(): copies up to N-1 first bytes from source string into destination string and ensures zero-termination afterwards. Replace all the relevant uses of strncpy/strncat/memcpy in libbpf with libbpf_strlcpy(). This also fixes the issue reported by Emmanuel Deloget in xsk.c where memcpy() could access source string beyond its end. Fixes: 2f6324a3937f8 (libbpf: Support shared umems between queues and devices) Reported-by: Emmanuel Deloget <emmanuel.deloget@eho.link> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211211004043.2374068-1-andrii@kernel.org
2021-12-14libbpf: Fix potential uninit memory readAndrii Nakryiko
In case of BPF_CORE_TYPE_ID_LOCAL we fill out target result explicitly. But targ_res itself isn't initialized in such a case, and subsequent call to bpf_core_patch_insn() might read uninitialized field (like fail_memsz_adjust in this case). So ensure that targ_res is zero-initialized for BPF_CORE_TYPE_ID_LOCAL case. This was reported by Coverity static analyzer. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211214010032.3843804-1-andrii@kernel.org
2021-12-13libbpf: Add doc comments for bpf_program__(un)pin()Grant Seltzer
This adds doc comments for the two bpf_program pinning functions, bpf_program__pin() and bpf_program__unpin() Signed-off-by: Grant Seltzer <grantseltzer@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211209232222.541733-1-grantseltzer@gmail.com
2021-12-12libbpf: Don't validate TYPE_ID relo's original imm valueAndrii Nakryiko
During linking, type IDs in the resulting linked BPF object file can change, and so ldimm64 instructions corresponding to BPF_CORE_TYPE_ID_TARGET and BPF_CORE_TYPE_ID_LOCAL CO-RE relos can get their imm value out of sync with actual CO-RE relocation information that's updated by BPF linker properly during linking process. We could teach BPF linker to adjust such instructions, but it feels a bit too much for linker to re-implement good chunk of bpf_core_patch_insns logic just for this. This is a redundant safety check for TYPE_ID relocations, as the real validation is in matching CO-RE specs, so if that works fine, it's very unlikely that there is something wrong with the instruction itself. So, instead, teach libbpf (and kernel) to ignore insn->imm for BPF_CORE_TYPE_ID_TARGET and BPF_CORE_TYPE_ID_LOCAL relos. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211213010706.100231-1-andrii@kernel.org
2021-12-11libbpf: Fix gen_loader assumption on number of programs.Alexei Starovoitov
libbpf's obj->nr_programs includes static and global functions. That number could be higher than the actual number of bpf programs going be loaded by gen_loader. Passing larger nr_programs to bpf_gen__init() doesn't hurt. Those exra stack slots will stay as zero. bpf_gen__finish() needs to check that actual number of progs that gen_loader saw is less than or equal to obj->nr_programs. Fixes: ba05fd36b851 ("libbpf: Perform map fd cleanup for gen_loader in case of error") Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-12-10Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski
Andrii Nakryiko says: ==================== bpf-next 2021-12-10 v2 We've added 115 non-merge commits during the last 26 day(s) which contain a total of 182 files changed, 5747 insertions(+), 2564 deletions(-). The main changes are: 1) Various samples fixes, from Alexander Lobakin. 2) BPF CO-RE support in kernel and light skeleton, from Alexei Starovoitov. 3) A batch of new unified APIs for libbpf, logging improvements, version querying, etc. Also a batch of old deprecations for old APIs and various bug fixes, in preparation for libbpf 1.0, from Andrii Nakryiko. 4) BPF documentation reorganization and improvements, from Christoph Hellwig and Dave Tucker. 5) Support for declarative initialization of BPF_MAP_TYPE_PROG_ARRAY in libbpf, from Hengqi Chen. 6) Verifier log fixes, from Hou Tao. 7) Runtime-bounded loops support with bpf_loop() helper, from Joanne Koong. 8) Extend branch record capturing to all platforms that support it, from Kajol Jain. 9) Light skeleton codegen improvements, from Kumar Kartikeya Dwivedi. 10) bpftool doc-generating script improvements, from Quentin Monnet. 11) Two libbpf v0.6 bug fixes, from Shuyi Cheng and Vincent Minet. 12) Deprecation warning fix for perf/bpf_counter, from Song Liu. 13) MAX_TAIL_CALL_CNT unification and MIPS build fix for libbpf, from Tiezhu Yang. 14) BTF_KING_TYPE_TAG follow-up fixes, from Yonghong Song. 15) Selftests fixes and improvements, from Ilya Leoshkevich, Jean-Philippe Brucker, Jiri Olsa, Maxim Mikityanskiy, Tirthendu Sarkar, Yucong Sun, and others. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (115 commits) libbpf: Add "bool skipped" to struct bpf_map libbpf: Fix typo in btf__dedup@LIBBPF_0.0.2 definition bpftool: Switch bpf_object__load_xattr() to bpf_object__load() selftests/bpf: Remove the only use of deprecated bpf_object__load_xattr() selftests/bpf: Add test for libbpf's custom log_buf behavior selftests/bpf: Replace all uses of bpf_load_btf() with bpf_btf_load() libbpf: Deprecate bpf_object__load_xattr() libbpf: Add per-program log buffer setter and getter libbpf: Preserve kernel error code and remove kprobe prog type guessing libbpf: Improve logging around BPF program loading libbpf: Allow passing user log setting through bpf_object_open_opts libbpf: Allow passing preallocated log_buf when loading BTF into kernel libbpf: Add OPTS-based bpf_btf_load() API libbpf: Fix bpf_prog_load() log_buf logic for log_level 0 samples/bpf: Remove unneeded variable bpf: Remove redundant assignment to pointer t selftests/bpf: Fix a compilation warning perf/bpf_counter: Use bpf_map_create instead of bpf_create_map samples: bpf: Fix 'unknown warning group' build warning on Clang samples: bpf: Fix xdp_sample_user.o linking with Clang ... ==================== Link: https://lore.kernel.org/r/20211210234746.2100561-1-andrii@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-10libbpf: Add "bool skipped" to struct bpf_mapShuyi Cheng
Fix error: "failed to pin map: Bad file descriptor, path: /sys/fs/bpf/_rodata_str1_1." In the old kernel, the global data map will not be created, see [0]. So we should skip the pinning of the global data map to avoid bpf_object__pin_maps returning error. Therefore, when the map is not created, we mark “map->skipped" as true and then check during relocation and during pinning. Fixes: 16e0c35c6f7a ("libbpf: Load global data maps lazily on legacy kernels") Signed-off-by: Shuyi Cheng <chengshuyi@linux.alibaba.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2021-12-10libbpf: Fix typo in btf__dedup@LIBBPF_0.0.2 definitionVincent Minet
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: Deprecate bpf_object__load_xattr()Andrii Nakryiko
Deprecate non-extensible bpf_object__load_xattr() in v0.8 ([0]). With log_level control through bpf_object_open_opts or bpf_program__set_log_level(), we are finally at the point where bpf_object__load_xattr() doesn't provide any functionality that can't be accessed through other (better) ways. The other feature, target_btf_path, is also controllable through bpf_object_open_opts. [0] Closes: https://github.com/libbpf/libbpf/issues/289 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211209193840.1248570-9-andrii@kernel.org
2021-12-10libbpf: Add per-program log buffer setter and getterAndrii Nakryiko
Allow to set user-provided log buffer on a per-program basis ([0]). This gives great deal of flexibility in terms of which programs are loaded with logging enabled and where corresponding logs go. Log buffer set with bpf_program__set_log_buf() overrides kernel_log_buf and kernel_log_size settings set at bpf_object open time through bpf_object_open_opts, if any. Adjust bpf_object_load_prog_instance() logic to not perform own log buf allocation and load retry if custom log buffer is provided by the user. [0] Closes: https://github.com/libbpf/libbpf/issues/418 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211209193840.1248570-8-andrii@kernel.org
2021-12-10libbpf: Preserve kernel error code and remove kprobe prog type guessingAndrii Nakryiko
Instead of rewriting error code returned by the kernel of prog load with libbpf-sepcific variants pass through the original error. There is now also no need to have a backup generic -LIBBPF_ERRNO__LOAD fallback error as bpf_prog_load() guarantees that errno will be properly set no matter what. Also drop a completely outdated and pretty useless BPF_PROG_TYPE_KPROBE guess logic. It's not necessary and neither it's helpful in modern BPF applications. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211209193840.1248570-7-andrii@kernel.org
2021-12-10libbpf: Improve logging around BPF program loadingAndrii Nakryiko
Add missing "prog '%s': " prefixes in few places and use consistently markers for beginning and end of program load logs. Here's an example of log output: libbpf: prog 'handler': BPF program load failed: Permission denied libbpf: -- BEGIN PROG LOAD LOG --- arg#0 reference type('UNKNOWN ') size cannot be determined: -22 ; out1 = in1; 0: (18) r1 = 0xffffc9000cdcc000 2: (61) r1 = *(u32 *)(r1 +0) ... 81: (63) *(u32 *)(r4 +0) = r5 R1_w=map_value(id=0,off=16,ks=4,vs=20,imm=0) R4=map_value(id=0,off=400,ks=4,vs=16,imm=0) invalid access to map value, value_size=16 off=400 size=4 R4 min value is outside of the allowed memory range processed 63 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0 -- END PROG LOAD LOG -- libbpf: failed to load program 'handler' libbpf: failed to load object 'test_skeleton' The entire verifier log, including BEGIN and END markers are now always youtput during a single print callback call. This should make it much easier to post-process or parse it, if necessary. It's not an explicit API guarantee, but it can be reasonably expected to stay like that. Also __bpf_object__open is renamed to bpf_object_open() as it's always an adventure to find the exact function that implements bpf_object's open phase, so drop the double underscored and use internal libbpf naming convention. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211209193840.1248570-6-andrii@kernel.org
2021-12-10libbpf: Allow passing user log setting through bpf_object_open_optsAndrii Nakryiko
Allow users to provide their own custom log_buf, log_size, and log_level at bpf_object level through bpf_object_open_opts. This log_buf will be used during BTF loading. Subsequent patch will use same log_buf during BPF program loading, unless overriden at per-bpf_program level. When such custom log_buf is provided, libbpf won't be attempting retrying loading of BTF to try to provide its own log buffer to capture kernel's error log output. User is responsible to provide big enough buffer, otherwise they run a risk of getting -ENOSPC error from the bpf() syscall. See also comments in bpf_object_open_opts regarding log_level and log_buf interactions. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211209193840.1248570-5-andrii@kernel.org
2021-12-10libbpf: Allow passing preallocated log_buf when loading BTF into kernelAndrii Nakryiko
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
2021-12-10libbpf: Add OPTS-based bpf_btf_load() APIAndrii Nakryiko
Similar to previous bpf_prog_load() and bpf_map_create() APIs, add bpf_btf_load() API which is taking optional OPTS struct. Schedule bpf_load_btf() for deprecation in v0.8 ([0]). This makes naming consistent with BPF_BTF_LOAD command, sets up an API for extensibility in the future, moves options parameters (log-related fields) into optional options, and also allows to pass log_level directly. It also removes log buffer auto-allocation logic from low-level API (consistent with bpf_prog_load() behavior), but preserves a special treatment of log_level == 0 with non-NULL log_buf, which matches low-level bpf_prog_load() and high-level libbpf APIs for BTF and program loading behaviors. [0] Closes: https://github.com/libbpf/libbpf/issues/419 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211209193840.1248570-3-andrii@kernel.org
2021-12-10libbpf: Fix bpf_prog_load() log_buf logic for log_level 0Andrii Nakryiko
To unify libbpf APIs behavior w.r.t. log_buf and log_level, fix bpf_prog_load() to follow the same logic as bpf_btf_load() and high-level bpf_object__load() API will follow in the subsequent patches: - if log_level is 0 and non-NULL log_buf is provided by a user, attempt load operation initially with no log_buf and log_level set; - if successful, we are done, return new FD; - on error, retry the load operation with log_level bumped to 1 and log_buf set; this way verbose logging will be requested only when we are sure that there is a failure, but will be fast in the common/expected success case. Of course, user can still specify log_level > 0 from the very beginning to force log collection. 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/20211209193840.1248570-2-andrii@kernel.org
2021-12-07perf evlist: Allow setting arbitrary leaderIan Rogers
The leader of a group is the first, but allow it to be an arbitrary list member so that for Intel topdown events slots may always be the group leader. Reviewed-by: Kajol Jain <kjain@linux.ibm.com> Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: John Garry <john.garry@huawei.com> Cc: Kajol Jain <kjain@linux.ibm.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Clarke <pc@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Riccardo Mancini <rickyman7@gmail.com> Cc: Stephane Eranian <eranian@google.com> Cc: Vineet Singh <vineet.singh@intel.com> Link: http://lore.kernel.org/lkml/20211130174945.247604-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-12-07libperf tests: Add test_stat_multiplexing testShunsuke Nakamura
Adds a test for a counter obtained using read() system call during multiplexing. $ sudo make tests -C ./tools/lib/perf/ V=1 make: Entering directory '/home/nakamura/build_work/build_kernel/linux_kernel/linux/tools/lib/perf' make -f /home/nakamura/build_work/build_kernel/linux_kernel/linux/tools/build/Makefile.build dir=. obj=libperf make -C /home/nakamura/build_work/build_kernel/linux_kernel/linux/tools/lib/api/ O= libapi.a make -f /home/nakamura/build_work/build_kernel/linux_kernel/linux/tools/build/Makefile.build dir=./fd obj=libapi make -f /home/nakamura/build_work/build_kernel/linux_kernel/linux/tools/build/Makefile.build dir=./fs obj=libapi make -f /home/nakamura/build_work/build_kernel/linux_kernel/linux/tools/build/Makefile.build dir=. obj=tests make -f /home/nakamura/build_work/build_kernel/linux_kernel/linux/tools/build/Makefile.build dir=./tests obj=tests running static: - running tests/test-cpumap.c...OK - running tests/test-threadmap.c...OK - running tests/test-evlist.c... Event 0 -- Raw count = 298049842, run = 270269503, enable = 456262127 Scaled count = 503160191 (59.24%, 270269503/456262127) Event 1 -- Raw count = 299134173, run = 271075173, enable = 456257234 Scaled count = 503484435 (59.41%, 271075173/456257234) Event 2 -- Raw count = 300461996, run = 272069283, enable = 456253417 Scaled count = 503867290 (59.63%, 272069283/456253417) Event 3 -- Raw count = 301308704, run = 273063387, enable = 456249352 Scaled count = 503443183 (59.85%, 273063387/456249352) Event 4 -- Raw count = 302531164, run = 274102932, enable = 456244712 Scaled count = 503563543 (60.08%, 274102932/456244712) Event 5 -- Raw count = 303710254, run = 275406214, enable = 456228165 Scaled count = 503115633 (60.37%, 275406214/456228165) Event 6 -- Raw count = 304531302, run = 276396076, enable = 456221130 Scaled count = 502661313 (60.58%, 276396076/456221130) Event 7 -- Raw count = 304486460, run = 276601890, enable = 456213754 Scaled count = 502205212 (60.63%, 276601890/456213754) Event 8 -- Raw count = 304116681, run = 276631326, enable = 456205562 Scaled count = 501532936 (60.64%, 276631326/456205562) Event 9 -- Raw count = 303567766, run = 276188567, enable = 456196839 Scaled count = 501420666 (60.54%, 276188567/456196839) Event 10 -- Raw count = 302238014, run = 275144001, enable = 456185300 Scaled count = 501106833 (60.31%, 275144001/456185300) Event 11 -- Raw count = 300805716, run = 273824589, enable = 456175608 Scaled count = 501124573 (60.03%, 273824589/456175608) Event 12 -- Raw count = 299959051, run = 272834556, enable = 456166593 Scaled count = 501517477 (59.81%, 272834556/456166593) Event 13 -- Raw count = 299037090, run = 271820805, enable = 456157086 Scaled count = 501830195 (59.59%, 271820805/456157086) Event 14 -- Raw count = 298327042, run = 270784311, enable = 456147546 Scaled count = 502544433 (59.36%, 270784311/456147546) Expected: 501614268 High: 503867290 Low: 298049842 Average: 502438527 Average Error = 0.16% OK - running tests/test-evsel.c... loop = 65536, count = 328182 loop = 131072, count = 660214 loop = 262144, count = 1315534 loop = 524288, count = 2635364 loop = 1048576, count = 5271971 loop = 65536, count = 491952 loop = 131072, count = 850061 loop = 262144, count = 1648608 loop = 524288, count = 3162059 loop = 1048576, count = 6353393 OK running dynamic: - running tests/test-cpumap.c...OK - running tests/test-threadmap.c...OK - running tests/test-evlist.c... Event 0 -- Raw count = 300218292, run = 297528154, enable = 496789343 Scaled count = 501281125 (59.89%, 297528154/496789343) Event 1 -- Raw count = 301438606, run = 298515328, enable = 496784768 Scaled count = 501649643 (60.09%, 298515328/496784768) Event 2 -- Raw count = 302342618, run = 298798983, enable = 496782015 Scaled count = 502673648 (60.15%, 298798983/496782015) Event 3 -- Raw count = 303132319, run = 299230407, enable = 496778508 Scaled count = 503256412 (60.23%, 299230407/496778508) Event 4 -- Raw count = 302758195, run = 299218047, enable = 496774243 Scaled count = 502651743 (60.23%, 299218047/496774243) Event 5 -- Raw count = 303158458, run = 299204274, enable = 496769146 Scaled count = 503334281 (60.23%, 299204274/496769146) Event 6 -- Raw count = 303471397, run = 299197479, enable = 496763124 Scaled count = 503859189 (60.23%, 299197479/496763124) Event 7 -- Raw count = 303583387, run = 299196861, enable = 496756458 Scaled count = 504039405 (60.23%, 299196861/496756458) Event 8 -- Raw count = 303096897, run = 299186924, enable = 496748667 Scaled count = 503240507 (60.23%, 299186924/496748667) Event 9 -- Raw count = 301424173, run = 297845086, enable = 496739994 Scaled count = 502709122 (59.96%, 297845086/496739994) Event 10 -- Raw count = 300876415, run = 296851339, enable = 496729034 Scaled count = 503464297 (59.76%, 296851339/496729034) Event 11 -- Raw count = 300239338, run = 296547963, enable = 496719538 Scaled count = 502902612 (59.70%, 296547963/496719538) Event 12 -- Raw count = 299751948, run = 296547195, enable = 496710036 Scaled count = 502077926 (59.70%, 296547195/496710036) Event 13 -- Raw count = 299341883, run = 296549981, enable = 496700423 Scaled count = 501376663 (59.70%, 296549981/496700423) Event 14 -- Raw count = 299145476, run = 296561684, enable = 496690949 Scaled count = 501018366 (59.71%, 296561684/496690949) Expected: 501669431 High: 504039405 Low: 300218292 Average: 502635662 Average Error = 0.19% OK - running tests/test-evsel.c... loop = 65536, count = 329275 loop = 131072, count = 664638 loop = 262144, count = 1315367 loop = 524288, count = 2629617 loop = 1048576, count = 5273657 loop = 65536, count = 459641 loop = 131072, count = 978402 loop = 262144, count = 1581219 loop = 524288, count = 3774908 loop = 1048576, count = 7694417 OK make: Leaving directory '/home/nakamura/build_work/build_kernel/linux_kernel/linux/tools/lib/perf' Signed-off-by: Shunsuke Nakamura <nakamura.shun@fujitsu.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211109085831.3770594-4-nakamura.shun@fujitsu.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-12-07libperf: Remove scaling process from perf_mmap__read_self()Shunsuke Nakamura
Remove the scaling process from perf_mmap__read_self(), and unify the counters that can be obtained from perf_evsel__read() to "no scaling". Signed-off-by: Shunsuke Nakamura <nakamura.shun@fujitsu.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211109085831.3770594-3-nakamura.shun@fujitsu.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-12-07libperf: Adopt perf_counts_values__scale() from tools/perf/utilShunsuke Nakamura
Move perf_counts_values__scale() from tools/perf/util to tools/lib/perf so that it can be used with libperf. Committer notes: As noted by Jiri, use __s8 instead of s8 on the exported function. Signed-off-by: Shunsuke Nakamura <nakamura.shun@fujitsu.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211109085831.3770594-2-nakamura.shun@fujitsu.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-12-06libbpf: Add doc comments in libbpf.hGrant Seltzer
This adds comments above functions in libbpf.h which document their uses. These comments are of a format that doxygen and sphinx can pick up and render. These are rendered by libbpf.readthedocs.org These doc comments are for: - bpf_object__open_file() - bpf_object__open_mem() - bpf_program__attach_uprobe() - bpf_program__attach_uprobe_opts() Signed-off-by: Grant Seltzer <grantseltzer@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211206203709.332530-1-grantseltzer@gmail.com
2021-12-06libbpf: Fix trivial typohuangxuesen
Fix typo in comment from 'bpf_skeleton_map' to 'bpf_map_skeleton' and from 'bpf_skeleton_prog' to 'bpf_prog_skeleton'. Signed-off-by: huangxuesen <huangxuesen@kuaishou.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1638755236-3851199-1-git-send-email-hxseverything@gmail.com
2021-12-06libtraceevent: Add __rel_loc relative location attribute supportMasami Hiramatsu
Add '__rel_loc' new dynamic data location attribute which encodes the data location from the next to the field itself. This is similar to the '__data_loc' but the location offset is not from the event entry but from the next of the field. This patch adds '__rel_loc' decoding support in the libtraceevent. Link: https://lkml.kernel.org/r/163757343994.510314.13241077597729303802.stgit@devnote2 Cc: Beau Belgrave <beaub@linux.microsoft.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-12-03libbpf: Reduce bpf_core_apply_relo_insn() stack usage.Alexei Starovoitov
Reduce bpf_core_apply_relo_insn() stack usage and bump BPF_CORE_SPEC_MAX_LEN limit back to 64. Fixes: 29db4bea1d10 ("bpf: Prepare relo_core.c for kernel duty.") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211203182836.16646-1-alexei.starovoitov@gmail.com
2021-12-02libbpf: Deprecate bpf_prog_load_xattr() APIAndrii Nakryiko
bpf_prog_load_xattr() is high-level API that's named as a low-level BPF_PROG_LOAD wrapper APIs, but it actually operates on struct bpf_object. It's badly and confusingly misnamed as it will load all the progs insige bpf_object, returning prog_fd of the very first BPF program. It also has a bunch of ad-hoc things like log_level override, map_ifindex auto-setting, etc. All this can be expressed more explicitly and cleanly through existing libbpf APIs. This patch marks bpf_prog_load_xattr() for deprecation in libbpf v0.8 ([0]). [0] Closes: https://github.com/libbpf/libbpf/issues/308 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211201232824.3166325-10-andrii@kernel.org
2021-12-02libbpf: Add API to get/set log_level at per-program levelAndrii Nakryiko
Add bpf_program__set_log_level() and bpf_program__log_level() to fetch and adjust log_level sent during BPF_PROG_LOAD command. This allows to selectively request more or less verbose output in BPF verifier log. Also bump libbpf version to 0.7 and make these APIs the first in v0.7. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211201232824.3166325-3-andrii@kernel.org
2021-12-02libbpf: Use __u32 fields in bpf_map_create_optsAndrii Nakryiko
Corresponding Linux UAPI struct uses __u32, not int, so keep it consistent. Fixes: 992c4225419a ("libbpf: Unify low-level map creation APIs w/ new bpf_map_create()") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211201232824.3166325-2-andrii@kernel.org
2021-12-02libbpf: Clean gen_loader's attach kind.Alexei Starovoitov
The gen_loader has to clear attach_kind otherwise the programs without attach_btf_id will fail load if they follow programs with attach_btf_id. Fixes: 67234743736a ("libbpf: Generate loader program out of BPF ELF file.") 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/20211201181040.23337-12-alexei.starovoitov@gmail.com
2021-12-02libbpf: Support init of inner maps in light skeleton.Alexei Starovoitov
Add ability to initialize inner maps in light skeleton. 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/20211201181040.23337-11-alexei.starovoitov@gmail.com
2021-12-02libbpf: Use CO-RE in the kernel in light skeleton.Alexei Starovoitov
Without lskel the CO-RE relocations are processed by libbpf before any other work is done. Instead, when lskel is needed, remember relocation as RELO_CORE kind. Then when loader prog is generated for a given bpf program pass CO-RE relos of that program to gen loader via bpf_gen__record_relo_core(). The gen loader will remember them as-is and pass it later as-is into the kernel. The normal libbpf flow is to process CO-RE early before call relos happen. In case of gen_loader the core relos have to be added to other relos to be copied together when bpf static function is appended in different places to other main bpf progs. During the copy the append_subprog_relos() will adjust insn_idx for normal relos and for RELO_CORE kind too. When that is done each struct reloc_desc has good relos for specific main prog. 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/20211201181040.23337-10-alexei.starovoitov@gmail.com
2021-12-02libbpf: Cleanup struct bpf_core_cand.Andrii Nakryiko
Remove two redundant fields from struct bpf_core_cand. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-8-alexei.starovoitov@gmail.com
2021-12-02bpf: Pass a set of bpf_core_relo-s to prog_load command.Alexei Starovoitov
struct bpf_core_relo is generated by llvm and processed by libbpf. It's a de-facto uapi. With CO-RE in the kernel the struct bpf_core_relo becomes uapi de-jure. Add an ability to pass a set of 'struct bpf_core_relo' to prog_load command and let the kernel perform CO-RE relocations. Note the struct bpf_line_info and struct bpf_func_info have the same layout when passed from LLVM to libbpf and from libbpf to the kernel except "insn_off" fields means "byte offset" when LLVM generates it. Then libbpf converts it to "insn index" to pass to the kernel. The struct bpf_core_relo's "insn_off" field is always "byte offset". 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/20211201181040.23337-6-alexei.starovoitov@gmail.com
2021-12-02bpf: Define enum bpf_core_relo_kind as uapi.Alexei Starovoitov
enum bpf_core_relo_kind is generated by llvm and processed by libbpf. It's a de-facto uapi. With CO-RE in the kernel the bpf_core_relo_kind values become uapi de-jure. Also rename them with BPF_CORE_ prefix to distinguish from conflicting names in bpf_core_read.h. The enums bpf_field_info_kind, bpf_type_id_kind, bpf_type_info_kind, bpf_enum_value_kind are passing different values from bpf program into llvm. 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/20211201181040.23337-5-alexei.starovoitov@gmail.com
2021-12-02bpf: Prepare relo_core.c for kernel duty.Alexei Starovoitov
Make relo_core.c to be compiled for the kernel and for user space libbpf. Note the patch is reducing BPF_CORE_SPEC_MAX_LEN from 64 to 32. This is the maximum number of nested structs and arrays. For example: struct sample { int a; struct { int b[10]; }; }; struct sample *s = ...; int *y = &s->b[5]; This field access is encoded as "0:1:0:5" and spec len is 4. The follow up patch might bump it back to 64. 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/20211201181040.23337-4-alexei.starovoitov@gmail.com
2021-12-02libbpf: Replace btf__type_by_id() with btf_type_by_id().Alexei Starovoitov
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
2021-11-30libbpf: Avoid reload of imm for weak, unresolved, repeating ksymKumar Kartikeya Dwivedi
Alexei pointed out that we can use BPF_REG_0 which already contains imm from move_blob2blob computation. Note that we now compare the second insn's imm, but this should not matter, since both will be zeroed out for the error case for the insn populated earlier. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20211122235733.634914-4-memxor@gmail.com
2021-11-30libbpf: Avoid double stores for success/failure case of ksym relocationsKumar Kartikeya Dwivedi
Instead, jump directly to success case stores in case ret >= 0, else do the default 0 value store and jump over the success case. This is better in terms of readability. Readjust the code for kfunc relocation as well to follow a similar pattern, also leads to easier to follow code now. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20211122235733.634914-3-memxor@gmail.com
2021-11-30libbpf: Remove duplicate assignmentsMehrdad Arshad Rad
There is a same action when load_attr.attach_btf_id is initialized. Signed-off-by: Mehrdad Arshad Rad <arshad.rad@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211128193337.10628-1-arshad.rad@gmail.com
2021-11-29libbpf: Silence uninitialized warning/error in btf_dump_dump_type_dataAlan Maguire
When compiling libbpf with gcc 4.8.5, we see: CC staticobjs/btf_dump.o btf_dump.c: In function ‘btf_dump_dump_type_data.isra.24’: btf_dump.c:2296:5: error: ‘err’ may be used uninitialized in this function [-Werror=maybe-uninitialized] if (err < 0) ^ cc1: all warnings being treated as errors make: *** [staticobjs/btf_dump.o] Error 1 While gcc 4.8.5 is too old to build the upstream kernel, it's possible it could be used to build standalone libbpf which suffers from the same problem. Silence the error by initializing 'err' to 0. The warning/error seems to be a false positive since err is set early in the function. Regardless we shouldn't prevent libbpf from building for this. Fixes: 920d16af9b42 ("libbpf: BTF dumper support for typed data") Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1638180040-8037-1-git-send-email-alan.maguire@oracle.com
2021-11-28libbpf: Support static initialization of BPF_MAP_TYPE_PROG_ARRAYHengqi Chen
Support static initialization of BPF_MAP_TYPE_PROG_ARRAY with a syntax similar to map-in-map initialization ([0]): SEC("socket") int tailcall_1(void *ctx) { return 0; } struct { __uint(type, BPF_MAP_TYPE_PROG_ARRAY); __uint(max_entries, 2); __uint(key_size, sizeof(__u32)); __array(values, int (void *)); } prog_array_init SEC(".maps") = { .values = { [1] = (void *)&tailcall_1, }, }; Here's the relevant part of libbpf debug log showing what's going on with prog-array initialization: libbpf: sec '.relsocket': collecting relocation for section(3) 'socket' libbpf: sec '.relsocket': relo #0: insn #2 against 'prog_array_init' libbpf: prog 'entry': found map 0 (prog_array_init, sec 4, off 0) for insn #0 libbpf: .maps relo #0: for 3 value 0 rel->r_offset 32 name 53 ('tailcall_1') libbpf: .maps relo #0: map 'prog_array_init' slot [1] points to prog 'tailcall_1' libbpf: map 'prog_array_init': created successfully, fd=5 libbpf: map 'prog_array_init': slot [1] set to prog 'tailcall_1' fd=6 [0] Closes: https://github.com/libbpf/libbpf/issues/354 Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211128141633.502339-2-hengqi.chen@gmail.com
2021-11-26bpf, mips: Fix build errors about __NR_bpf undeclaredTiezhu Yang
Add the __NR_bpf definitions to fix the following build errors for mips: $ cd tools/bpf/bpftool $ make [...] bpf.c:54:4: error: #error __NR_bpf not defined. libbpf does not support your arch. # error __NR_bpf not defined. libbpf does not support your arch. ^~~~~ bpf.c: In function ‘sys_bpf’: bpf.c:66:17: error: ‘__NR_bpf’ undeclared (first use in this function); did you mean ‘__NR_brk’? return syscall(__NR_bpf, cmd, attr, size); ^~~~~~~~ __NR_brk [...] In file included from gen_loader.c:15:0: skel_internal.h: In function ‘skel_sys_bpf’: skel_internal.h:53:17: error: ‘__NR_bpf’ undeclared (first use in this function); did you mean ‘__NR_brk’? return syscall(__NR_bpf, cmd, attr, size); ^~~~~~~~ __NR_brk We can see the following generated definitions: $ grep -r "#define __NR_bpf" arch/mips arch/mips/include/generated/uapi/asm/unistd_o32.h:#define __NR_bpf (__NR_Linux + 355) arch/mips/include/generated/uapi/asm/unistd_n64.h:#define __NR_bpf (__NR_Linux + 315) arch/mips/include/generated/uapi/asm/unistd_n32.h:#define __NR_bpf (__NR_Linux + 319) The __NR_Linux is defined in arch/mips/include/uapi/asm/unistd.h: $ grep -r "#define __NR_Linux" arch/mips arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux 4000 arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux 5000 arch/mips/include/uapi/asm/unistd.h:#define __NR_Linux 6000 That is to say, __NR_bpf is: 4000 + 355 = 4355 for mips o32, 6000 + 319 = 6319 for mips n32, 5000 + 315 = 5315 for mips n64. So use the GCC pre-defined macro _ABIO32, _ABIN32 and _ABI64 [1] to define the corresponding __NR_bpf. This patch is similar with commit bad1926dd2f6 ("bpf, s390: fix build for libbpf and selftest suite"). [1] https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config/mips/mips.h#l549 Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/1637804167-8323-1-git-send-email-yangtiezhu@loongson.cn
2021-11-26libbpf: Fix using invalidated memory in bpf_linkerAndrii Nakryiko
add_dst_sec() can invalidate bpf_linker's section index making dst_symtab pointer pointing into unallocated memory. Reinitialize dst_symtab pointer on each iteration to make sure it's always valid. Fixes: faf6ed321cf6 ("libbpf: Add BPF static linker APIs") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211124002325.1737739-7-andrii@kernel.org