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2025-03-30Merge tag 'bpf-next-6.15' of ↵Linus Torvalds14-124/+316
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Pull bpf updates from Alexei Starovoitov: "For this merge window we're splitting BPF pull request into three for higher visibility: main changes, res_spin_lock, try_alloc_pages. These are the main BPF changes: - Add DFA-based live registers analysis to improve verification of programs with loops (Eduard Zingerman) - Introduce load_acquire and store_release BPF instructions and add x86, arm64 JIT support (Peilin Ye) - Fix loop detection logic in the verifier (Eduard Zingerman) - Drop unnecesary lock in bpf_map_inc_not_zero() (Eric Dumazet) - Add kfunc for populating cpumask bits (Emil Tsalapatis) - Convert various shell based tests to selftests/bpf/test_progs format (Bastien Curutchet) - Allow passing referenced kptrs into struct_ops callbacks (Amery Hung) - Add a flag to LSM bpf hook to facilitate bpf program signing (Blaise Boscaccy) - Track arena arguments in kfuncs (Ihor Solodrai) - Add copy_remote_vm_str() helper for reading strings from remote VM and bpf_copy_from_user_task_str() kfunc (Jordan Rome) - Add support for timed may_goto instruction (Kumar Kartikeya Dwivedi) - Allow bpf_get_netns_cookie() int cgroup_skb programs (Mahe Tardy) - Reduce bpf_cgrp_storage_busy false positives when accessing cgroup local storage (Martin KaFai Lau) - Introduce bpf_dynptr_copy() kfunc (Mykyta Yatsenko) - Allow retrieving BTF data with BTF token (Mykyta Yatsenko) - Add BPF kfuncs to set and get xattrs with 'security.bpf.' prefix (Song Liu) - Reject attaching programs to noreturn functions (Yafang Shao) - Introduce pre-order traversal of cgroup bpf programs (Yonghong Song)" * tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (186 commits) selftests/bpf: Add selftests for load-acquire/store-release when register number is invalid bpf: Fix out-of-bounds read in check_atomic_load/store() libbpf: Add namespace for errstr making it libbpf_errstr bpf: Add struct_ops context information to struct bpf_prog_aux selftests/bpf: Sanitize pointer prior fclose() selftests/bpf: Migrate test_xdp_vlan.sh into test_progs selftests/bpf: test_xdp_vlan: Rename BPF sections bpf: clarify a misleading verifier error message selftests/bpf: Add selftest for attaching fexit to __noreturn functions bpf: Reject attaching fexit/fmod_ret to __noreturn functions bpf: Only fails the busy counter check in bpf_cgrp_storage_get if it creates storage bpf: Make perf_event_read_output accessible in all program types. bpftool: Using the right format specifiers bpftool: Add -Wformat-signedness flag to detect format errors selftests/bpf: Test freplace from user namespace libbpf: Pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_ID bpf: Return prog btf_id without capable check bpf: BPF token support for BPF_BTF_GET_FD_BY_ID bpf, x86: Fix objtool warning for timed may_goto bpf: Check map->record at the beginning of check_and_free_fields() ...
2025-03-21libbpf: Add namespace for errstr making it libbpf_errstrIan Rogers2-3/+6
When statically linking symbols can be replaced with those from other statically linked libraries depending on the link order and the hoped for "multiple definition" error may not appear. To avoid conflicts it is good practice to namespace symbols, this change renames errstr to libbpf_errstr. To avoid churn a #define is used to turn use of errstr(err) to libbpf_errstr(err). Fixes: 1633a83bf993 ("libbpf: Introduce errstr() for stringifying errno") Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250320222439.1350187-1-irogers@google.com
2025-03-17libbpf: Pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_IDMykyta Yatsenko5-9/+23
Pass BPF token from bpf_program__set_attach_target to BPF_BTF_GET_FD_BY_ID bpf command. When freplace program attaches to target program, it needs to look up for BTF of the target, this may require BPF token, if, for example, running from user namespace. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20250317174039.161275-4-mykyta.yatsenko5@gmail.com
2025-03-15libbpf: Split bpf object load into prepare/loadMykyta Yatsenko3-43/+117
Introduce bpf_object__prepare API: additional intermediate preparation step that performs ELF processing, relocations, prepares final state of BPF program instructions (accessible with bpf_program__insns()), creates and (potentially) pins maps, and stops short of loading BPF programs. We anticipate few use cases for this API, such as: * Use prepare to initialize bpf_token, without loading freplace programs, unlocking possibility to lookup BTF of other programs. * Execute prepare to obtain finalized BPF program instructions without loading programs, enabling tools like veristat to process one program at a time, without incurring cost of ELF parsing and processing. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250303135752.158343-4-mykyta.yatsenko5@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-15libbpf: Introduce more granular state for bpf_objectMykyta Yatsenko1-17/+22
We are going to split bpf_object loading into 2 stages: preparation and loading. This will increase flexibility when working with bpf_object and unlock some optimizations and use cases. This patch substitutes a boolean flag (loaded) by more finely-grained state for bpf_object. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250303135752.158343-3-mykyta.yatsenko5@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-03-15libbpf: Use map_is_created helper in map settersMykyta Yatsenko1-9/+9
Refactoring: use map_is_created helper in map setters that need to check the state of the map. This helps to reduce the number of the places that depend explicitly on the loaded flag, simplifying refactoring in the next patch of this set. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250303135752.158343-2-mykyta.yatsenko5@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-02-26libbpf: Implement bpf_usdt_arg_size BPF functionIhor Solodrai1-0/+32
Information about USDT argument size is implicitly stored in __bpf_usdt_arg_spec, but currently it's not accessbile to BPF programs that use USDT. Implement bpf_sdt_arg_size() that returns the size of an USDT argument in bytes. v1->v2: * do not add __bpf_usdt_arg_spec() helper v1: https://lore.kernel.org/bpf/20250220215904.3362709-1-ihor.solodrai@linux.dev/ Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20250224235756.2612606-1-ihor.solodrai@linux.dev
2025-02-26Merge tag 'perf-tools-fixes-for-v6.14-2-2025-02-25' of ↵Linus Torvalds1-13/+0
git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools Pull perf tools fixes from Arnaldo Carvalho de Melo: - Fix tools/ quiet build Makefile infrastructure that was broken when working on tools/perf/ without testing on other tools/ living utilities. * tag 'perf-tools-fixes-for-v6.14-2-2025-02-25' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: tools: Remove redundant quiet setup tools: Unify top-level quiet infrastructure
2025-02-25libbpf: Fix out-of-bound readNandakumar Edamana1-1/+1
In `set_kcfg_value_str`, an untrusted string is accessed with the assumption that it will be at least two characters long due to the presence of checks for opening and closing quotes. But the check for the closing quote (value[len - 1] != '"') misses the fact that it could be checking the opening quote itself in case of an invalid input that consists of just the opening quote. This commit adds an explicit check to make sure the string is at least two characters long. Signed-off-by: Nandakumar Edamana <nandakumar@nandakumar.co.in> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250221210110.3182084-1-nandakumar@nandakumar.co.in
2025-02-21libbpf: Fix hypothetical STT_SECTION extern NULL deref caseAndrii Nakryiko1-1/+1
Fix theoretical NULL dereference in linker when resolving *extern* STT_SECTION symbol against not-yet-existing ELF section. Not sure if it's possible in practice for valid ELF object files (this would require embedded assembly manipulations, at which point BTF will be missing), but fix the s/dst_sym/dst_sec/ typo guarding this condition anyways. Fixes: faf6ed321cf6 ("libbpf: Add BPF static linker APIs") Fixes: a46349227cd8 ("libbpf: Add linker extern resolution support for functions and global variables") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20250220002821.834400-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-02-20libbpf: Wrap libbpf API direct err with libbpf_errTao Chen1-13/+13
Just wrap the direct err with libbpf_err, keep consistency with other APIs. Signed-off-by: Tao Chen <chen.dylane@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20250219153711.29651-1-chen.dylane@linux.dev
2025-02-18tools: Remove redundant quiet setupCharlie Jenkins1-13/+0
Q is exported from Makefile.include so it is not necessary to manually set it. Reviewed-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Quentin Monnet <qmo@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Benjamin Tissoires <bentiss@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Eduard Zingerman <eddyz87@gmail.com> Cc: Hao Luo <haoluo@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: KP Singh <kpsingh@kernel.org> Cc: Lukasz Luba <lukasz.luba@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Mykola Lysenko <mykolal@fb.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Stanislav Fomichev <sdf@google.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Yonghong Song <yonghong.song@linux.dev> Cc: Zhang Rui <rui.zhang@intel.com> Link: https://lore.kernel.org/r/20250213-quiet_tools-v3-2-07de4482a581@rivosinc.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-02-15libbpf: fix LDX/STX/ST CO-RE relocation size adjustment logicAndrii Nakryiko1-4/+20
Libbpf has a somewhat obscure feature of automatically adjusting the "size" of LDX/STX/ST instruction (memory store and load instructions), based on originally recorded access size (u8, u16, u32, or u64) and the actual size of the field on target kernel. This is meant to facilitate using BPF CO-RE on 32-bit architectures (pointers are always 64-bit in BPF, but host kernel's BTF will have it as 32-bit type), as well as generally supporting safe type changes (unsigned integer type changes can be transparently "relocated"). One issue that surfaced only now, 5 years after this logic was implemented, is how this all works when dealing with fields that are arrays. This isn't all that easy and straightforward to hit (see selftests that reproduce this condition), but one of sched_ext BPF programs did hit it with innocent looking loop. Long story short, libbpf used to calculate entire array size, instead of making sure to only calculate array's element size. But it's the element that is loaded by LDX/STX/ST instructions (1, 2, 4, or 8 bytes), so that's what libbpf should check. This patch adjusts the logic for arrays and fixed the issue. Reported-by: Emil Tsalapatis <emil@etsalapatis.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20250207014809.1573841-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-02-06libbpf: Check the kflag of type tags in btf_dumpIhor Solodrai1-1/+4
If the kflag is set for a BTF type tag, then the tag represents an arbitrary __attribute__. Change btf_dump accordingly. Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250130201239.1429648-4-ihor.solodrai@linux.dev
2025-02-06libbpf: Introduce kflag for type_tags and decl_tags in BTFIhor Solodrai3-23/+68
Add the following functions to libbpf API: * btf__add_type_attr() * btf__add_decl_attr() These functions allow to add to BTF the type tags and decl tags with info->kflag set to 1. The kflag indicates that the tag directly encodes an __attribute__ and not a normal tag. See Documentation/bpf/btf.rst changes in the subsequent patch for details on the semantics. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250130201239.1429648-2-ihor.solodrai@linux.dev
2025-02-03libbpf: Fix accessing BTF.ext core_relo headerTony Ambardar1-2/+2
Update btf_ext_parse_info() to ensure the core_relo header is present before reading its fields. This avoids a potential buffer read overflow reported by the OSS Fuzz project. Fixes: cf579164e9ea ("libbpf: Support BTF.ext loading and output in either endianness") Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://issues.oss-fuzz.com/issues/388905046 Link: https://lore.kernel.org/bpf/20250125065236.2603346-1-itugrok@yahoo.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-01-17libbpf: Work around kernel inconsistently stripping '.llvm.' suffixAndrii Nakryiko1-1/+25
Some versions of kernel were stripping out '.llvm.<hash>' suffix from kerne symbols (produced by Clang LTO compilation) from function names reported in available_filter_functions, while kallsyms reported full original name. This confuses libbpf's multi-kprobe logic of finding all matching kernel functions for specified user glob pattern by joining available_filter_functions and kallsyms contents, because joining by full symbol name won't work for symbols containing '.llvm.<hash>' suffix. This was eventually fixed by [0] in the kernel, but we'd like to not regress multi-kprobe experience and add a work around for this bug on libbpf side, stripping kallsym's name if it matches user pattern and contains '.llvm.' suffix. [0] fb6a421fb615 ("kallsyms: Match symbols exactly with CONFIG_LTO_CLANG") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20250117003957.179331-1-andrii@kernel.org
2025-01-17libbpf: Fix incorrect traversal end type ID when marking BTF_IS_EMBEDDEDPu Lehui1-1/+1
When redirecting the split BTF to the vmlinux base BTF, we need to mark the distilled base struct/union members of split BTF structs/unions in id_map with BTF_IS_EMBEDDED. This indicates that these types must match both name and size later. Therefore, we need to traverse the entire split BTF, which involves traversing type IDs from nr_dist_base_types to nr_types. However, the current implementation uses an incorrect traversal end type ID, so let's correct it. Fixes: 19e00c897d50 ("libbpf: Split BTF relocation") Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250115100241.4171581-3-pulehui@huaweicloud.com
2025-01-17libbpf: Fix return zero when elf_begin failedPu Lehui1-0/+1
The error number of elf_begin is omitted when encapsulating the btf_find_elf_sections function. Fixes: c86f180ffc99 ("libbpf: Make btf_parse_elf process .BTF.base transparently") Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250115100241.4171581-2-pulehui@huaweicloud.com
2025-01-11libbpf: Add unique_match option for multi kprobeYonghong Song2-2/+15
Jordan reported an issue in Meta production environment where func try_to_wake_up() is renamed to try_to_wake_up.llvm.<hash>() by clang compiler at lto mode. The original 'kprobe/try_to_wake_up' does not work any more since try_to_wake_up() does not match the actual func name in /proc/kallsyms. There are a couple of ways to resolve this issue. For example, in attach_kprobe(), we could do lookup in /proc/kallsyms so try_to_wake_up() can be replaced by try_to_wake_up.llvm.<hach>(). Or we can force users to use bpf_program__attach_kprobe() where they need to lookup /proc/kallsyms to find out try_to_wake_up.llvm.<hach>(). But these two approaches requires extra work by either libbpf or user. Luckily, suggested by Andrii, multi kprobe already supports wildcard ('*') for symbol matching. In the above example, 'try_to_wake_up*' can match to try_to_wake_up() or try_to_wake_up.llvm.<hash>() and this allows bpf prog works for different kernels as some kernels may have try_to_wake_up() and some others may have try_to_wake_up.llvm.<hash>(). The original intention is to kprobe try_to_wake_up() only, so an optional field unique_match is added to struct bpf_kprobe_multi_opts. If the field is set to true, the number of matched functions must be one. Otherwise, the attachment will fail. In the above case, multi kprobe with 'try_to_wake_up*' and unique_match preserves user functionality. Reported-by: Jordan Rome <linux@jordanrome.com> Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250109174023.3368432-1-yonghong.song@linux.dev
2024-12-31libbpf: Set MFD_NOEXEC_SEAL when creating memfdDaniel Xu1-1/+13
Starting from 105ff5339f49 ("mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC") and until 1717449b4417 ("memfd: drop warning for missing exec-related flags"), the kernel would print a warning if neither MFD_NOEXEC_SEAL nor MFD_EXEC is set in memfd_create(). If libbpf runs on on a kernel between these two commits (eg. on an improperly backported system), it'll trigger this warning. To avoid this warning (and also be more secure), explicitly set MFD_NOEXEC_SEAL. But since libbpf can be run on potentially very old kernels, leave a fallback for kernels without MFD_NOEXEC_SEAL support. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Link: https://lore.kernel.org/r/6e62c2421ad7eb1da49cbf16da95aaaa7f94d394.1735594195.git.dxu@dxuuu.xyz Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-12-14libbpf: prog load: Allow to use fd_array_cntAnton Protopopov2-2/+6
Add new fd_array_cnt field to bpf_prog_load_opts and pass it in bpf_attr, if set. Signed-off-by: Anton Protopopov <aspsk@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241213130934.1087929-6-aspsk@isovalent.com
2024-12-13libbpf: Extend linker API to support in-memory ELF filesAlastair Robertson3-21/+150
The new_fd and add_fd functions correspond to the original new and add_file functions, but accept an FD instead of a file name. This gives API consumers the option of using anonymous files/memfds to avoid writing ELFs to disk. This new API will be useful for performing linking as part of bpftrace's JIT compilation. The add_buf function is a convenience wrapper that does the work of creating a memfd for the caller. Signed-off-by: Alastair Robertson <ajor@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241211164030.573042-3-ajor@meta.com
2024-12-13libbpf: Pull file-opening logic up to top-level functionsAlastair Robertson1-42/+42
Move the filename arguments and file-descriptor handling from init_output_elf() and linker_load_obj_file() and instead handle them at the top-level in bpf_linker__new() and bpf_linker__add_file(). This will allow the inner functions to be shared with a new, non-filename-based, API in the next commit. Signed-off-by: Alastair Robertson <ajor@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241211164030.573042-2-ajor@meta.com
2024-12-06libbpf: Fix segfault due to libelf functions not setting errnoQuentin Monnet1-14/+8
Libelf functions do not set errno on failure. Instead, it relies on its internal _elf_errno value, that can be retrieved via elf_errno (or the corresponding message via elf_errmsg()). From "man libelf": If a libelf function encounters an error it will set an internal error code that can be retrieved with elf_errno. Each thread maintains its own separate error code. The meaning of each error code can be determined with elf_errmsg, which returns a string describing the error. As a consequence, libbpf should not return -errno when a function from libelf fails, because an empty value will not be interpreted as an error and won't prevent the program to stop. This is visible in bpf_linker__add_file(), for example, where we call a succession of functions that rely on libelf: err = err ?: linker_load_obj_file(linker, filename, opts, &obj); err = err ?: linker_append_sec_data(linker, &obj); err = err ?: linker_append_elf_syms(linker, &obj); err = err ?: linker_append_elf_relos(linker, &obj); err = err ?: linker_append_btf(linker, &obj); err = err ?: linker_append_btf_ext(linker, &obj); If the object file that we try to process is not, in fact, a correct object file, linker_load_obj_file() may fail with errno not being set, and return 0. In this case we attempt to run linker_append_elf_sysms() and may segfault. This can happen (and was discovered) with bpftool: $ bpftool gen object output.o sample_ret0.bpf.c libbpf: failed to get ELF header for sample_ret0.bpf.c: invalid `Elf' handle zsh: segmentation fault (core dumped) bpftool gen object output.o sample_ret0.bpf.c Fix the issue by returning a non-null error code (-EINVAL) when libelf functions fail. Fixes: faf6ed321cf6 ("libbpf: Add BPF static linker APIs") Signed-off-by: Quentin Monnet <qmo@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241205135942.65262-1-qmo@kernel.org
2024-12-02libbpf: Improve debug message when the base BTF cannot be foundBen Olson1-1/+1
When running `bpftool` on a kernel module installed in `/lib/modules...`, this error is encountered if the user does not specify `--base-btf` to point to a valid base BTF (e.g. usually in `/sys/kernel/btf/vmlinux`). However, looking at the debug output to determine the cause of the error simply says `Invalid BTF string section`, which does not point to the actual source of the error. This just improves that debug message to tell users what happened. Signed-off-by: Ben Olson <matthew.olson@intel.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/Z0YqzQ5lNz7obQG7@bolson-desk Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-12-02libbpf: don't adjust USDT semaphore address if .stapsdt.base addr is missingAndrii Nakryiko1-1/+1
USDT ELF note optionally can record an offset of .stapsdt.base, which is used to make adjustments to USDT target attach address. Currently, libbpf will do this address adjustment unconditionally if it finds .stapsdt.base ELF section in target binary. But there is a corner case where .stapsdt.base ELF section is present, but specific USDT note doesn't reference it. In such case, libbpf will basically just add base address and end up with absolutely incorrect USDT target address. This adjustment has to be done only if both .stapsdt.sema section is present and USDT note is recording a reference to it. Fixes: 74cc6311cec9 ("libbpf: Add USDT notes parsing and resolution logic") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20241121224558.796110-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-16libbpf: Change hash_combine parameters from long to unsigned longSidong Yang1-1/+1
The hash_combine() could be trapped when compiled with sanitizer like "zig cc" or clang with signed-integer-overflow option. This patch parameters and return type to unsigned long to remove the potential overflow. Signed-off-by: Sidong Yang <sidong.yang@furiosa.ai> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20241116081054.65195-1-sidong.yang@furiosa.ai Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-15libbpf: Fix memory leak in bpf_program__attach_uprobe_multiJiri Olsa1-6/+5
Andrii reported memory leak detected by Coverity on error path in bpf_program__attach_uprobe_multi. Fixing that by moving the check earlier before the offsets allocations. Reported-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241115115843.694337-1-jolsa@kernel.org
2024-11-12libbpf: Stringify errno in log messages in the remaining codeMykyta Yatsenko6-53/+56
Convert numeric error codes into the string representations in log messages in the rest of libbpf source files. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241111212919.368971-5-mykyta.yatsenko5@gmail.com
2024-11-12libbpf: Stringify errno in log messages in btf*.cMykyta Yatsenko2-13/+16
Convert numeric error codes into the string representations in log messages in btf.c and btf_dump.c. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241111212919.368971-4-mykyta.yatsenko5@gmail.com
2024-11-12libbpf: Stringify errno in log messages in libbpf.cMykyta Yatsenko1-200/+156
Convert numeric error codes into the string representations in log messages in libbpf.c. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241111212919.368971-3-mykyta.yatsenko5@gmail.com
2024-11-12libbpf: Introduce errstr() for stringifying errnoMykyta Yatsenko2-0/+78
Add function errstr(int err) that allows converting numeric error codes into string representations. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241111212919.368971-2-mykyta.yatsenko5@gmail.com
2024-11-11libbpf: Add support for uprobe multi session attachJiri Olsa3-3/+20
Adding support to attach program in uprobe session mode with bpf_program__attach_uprobe_multi function. Adding session bool to bpf_uprobe_multi_opts struct that allows to load and attach the bpf program via uprobe session. the attachment to create uprobe multi session. Also adding new program loader section that allows: SEC("uprobe.session/bpf_fentry_test*") and loads/attaches uprobe program as uprobe session. Adding sleepable hook (uprobe.session.s) as well. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241108134544.480660-6-jolsa@kernel.org
2024-11-11bpf: Add support for uprobe multi session attachJiri Olsa1-0/+1
Adding support to attach BPF program for entry and return probe of the same function. This is common use case which at the moment requires to create two uprobe multi links. Adding new BPF_TRACE_UPROBE_SESSION attach type that instructs kernel to attach single link program to both entry and exit probe. It's possible to control execution of the BPF program on return probe simply by returning zero or non zero from the entry BPF program execution to execute or not the BPF program on return probe respectively. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241108134544.480660-4-jolsa@kernel.org
2024-10-29libbpf: start v1.6 development cycleAndrii Nakryiko2-1/+4
With libbpf v1.5.0 release out, start v1.6 dev cycle. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241029184045.581537-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24libbpf: define __uptr.Kui-Feng Lee1-0/+1
Make __uptr available to BPF programs to enable them to define uptrs. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20241023234759.860539-8-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24libbpf: move global data mmap()'ing into bpf_object__load()Andrii Nakryiko1-43/+40
Since BPF skeleton inception libbpf has been doing mmap()'ing of global data ARRAY maps in bpf_object__load_skeleton() API, which is used by code generated .skel.h files (i.e., by BPF skeletons only). This is wrong because if BPF object is loaded through generic bpf_object__load() API, global data maps won't be re-mmap()'ed after load step, and memory pointers returned from bpf_map__initial_value() would be wrong and won't reflect the actual memory shared between BPF program and user space. bpf_map__initial_value() return result is rarely used after load, so this went unnoticed for a really long time, until bpftrace project attempted to load BPF object through generic bpf_object__load() API and then used BPF subskeleton instantiated from such bpf_object. It turned out that .data/.rodata/.bss data updates through such subskeleton was "blackholed", all because libbpf wouldn't re-mmap() those maps during bpf_object__load() phase. Long story short, this step should be done by libbpf regardless of BPF skeleton usage, right after BPF map is created in the kernel. This patch moves this functionality into bpf_object__populate_internal_map() to achieve this. And bpf_object__load_skeleton() is now simple and almost trivial, only propagating these mmap()'ed pointers into user-supplied skeleton structs. We also do trivial adjustments to error reporting inside bpf_object__populate_internal_map() for consistency with the rest of libbpf's map-handling code. Reported-by: Alastair Robertson <ajor@meta.com> Reported-by: Jonathan Wiepert <jwiepert@meta.com> Fixes: d66562fba1ce ("libbpf: Add BPF object skeleton support") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241023043908.3834423-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24libbpf: Prevent compiler warnings/errorsEder Zulian1-2/+2
Initialize 'new_off' and 'pad_bits' to 0 and 'pad_type' to NULL in btf_dump_emit_bit_padding to prevent compiler warnings/errors which are observed when compiling with 'EXTRA_CFLAGS=-g -Og' options, but do not happen when compiling with current default options. For example, when compiling libbpf with $ make "EXTRA_CFLAGS=-g -Og" -C tools/lib/bpf/ clean all Clang version 17.0.6 and GCC 13.3.1 fail to compile btf_dump.c due to following errors: btf_dump.c: In function ‘btf_dump_emit_bit_padding’: btf_dump.c:903:42: error: ‘new_off’ may be used uninitialized [-Werror=maybe-uninitialized] 903 | if (new_off > cur_off && new_off <= next_off) { | ~~~~~~~~^~~~~~~~~~~ btf_dump.c:870:13: note: ‘new_off’ was declared here 870 | int new_off, pad_bits, bits, i; | ^~~~~~~ btf_dump.c:917:25: error: ‘pad_type’ may be used uninitialized [-Werror=maybe-uninitialized] 917 | btf_dump_printf(d, "\n%s%s: %d;", pfx(lvl), pad_type, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 918 | in_bitfield ? new_off - cur_off : 0); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ btf_dump.c:871:21: note: ‘pad_type’ was declared here 871 | const char *pad_type; | ^~~~~~~~ btf_dump.c:930:20: error: ‘pad_bits’ may be used uninitialized [-Werror=maybe-uninitialized] 930 | if (bits == pad_bits) { | ^ btf_dump.c:870:22: note: ‘pad_bits’ was declared here 870 | int new_off, pad_bits, bits, i; | ^~~~~~~~ cc1: all warnings being treated as errors Signed-off-by: Eder Zulian <ezulian@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20241022172329.3871958-3-ezulian@redhat.com
2024-10-11libbpf: Fix possible compiler warnings in hashmapNamhyung Kim1-10/+10
The hashmap__for_each_entry[_safe] is accessing 'map' as a pointer. But it does without parentheses so passing a static hash map with an ampersand (like '&slab_hash') will cause compiler warnings due to unmatched types as '->' operator has a higher precedence. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241011170021.1490836-1-namhyung@kernel.org
2024-10-11libbpf: never interpret subprogs in .text as entry programsAndrii Nakryiko1-1/+1
Libbpf pre-1.0 had a legacy logic of allowing singular non-annotated (i.e., not having explicit SEC() annotation) function to be treated as sole entry BPF program (unless there were other explicit entry programs). This behavior was dropped during libbpf 1.0 transition period (unless LIBBPF_STRICT_SEC_NAME flag was unset in libbpf_mode). When 1.0 was released and all the legacy behavior was removed, the bug slipped through leaving this legacy behavior around. Fix this for good, as it actually causes very confusing behavior if BPF object file only has subprograms, but no entry programs. Fixes: bd054102a8c7 ("libbpf: enforce strict libbpf 1.0 behaviors") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241010211731.4121837-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-10libbpf: fix sym_is_subprog() logic for weak global subprogsAndrii Nakryiko1-1/+1
sym_is_subprog() is incorrectly rejecting relocations against *weak* global subprogs. Fix that by realizing that STB_WEAK is also a global function. While it seems like verifier doesn't support taking an address of non-static subprog right now, it's still best to fix support for it on libbpf side, otherwise users will get a very confusing error during BPF skeleton generation or static linking due to misinterpreted relocation: libbpf: prog 'handle_tp': bad map relo against 'foo' in section '.text' Error: failed to open BPF object file: Relocation failed It's clearly not a map relocation, but is treated and reported as such without this fix. Fixes: 53eddb5e04ac ("libbpf: Support subprog address relocation") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241009011554.880168-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-08libbpf: Do not resolve size on duplicate FUNCsEric Long1-0/+4
FUNCs do not have sizes, thus currently btf__resolve_size will fail with -EINVAL. Add conditions so that we only update size when the BTF object is not function or function prototype. Signed-off-by: Eric Long <i@hack3r.moe> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20241002-libbpf-dup-extern-funcs-v4-1-560eb460ff90@hack3r.moe
2024-10-08libbpf: Add missing per-arch include pathBjörn Töpel1-1/+2
libbpf does not include the per-arch tools include path, e.g. tools/arch/riscv/include. Some architectures depend those files to build properly. Include tools/arch/$(SUBARCH)/include in the libbpf build. Fixes: 6d74d178fe6e ("tools: Add riscv barrier implementation") Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240927131355.350918-1-bjorn@kernel.org
2024-10-04libbpf: Support creating light skeleton of either endiannessTony Ambardar4-53/+139
Track target endianness in 'struct bpf_gen' and process in-memory data in native byte-order, but on finalization convert the embedded loader BPF insns to target endianness. The light skeleton also includes a target-accessed data blob which is heterogeneous and thus difficult to convert to target byte-order on finalization. Add support functions to convert data to target endianness as it is added to the blob. Also add additional debug logging for data blob structure details and skeleton loading. Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/569562e1d5bf1cce80a1f1a3882461ee2da1ffd5.1726475448.git.tony.ambardar@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-04libbpf: Support linking bpf objects of either endiannessTony Ambardar1-16/+62
Allow static linking object files of either endianness, checking that input files have consistent byte-order, and setting output endianness from input. Linking requires in-memory processing of programs, relocations, sections, etc. in native endianness, and output conversion to target byte-order. This is enabled by built-in ELF translation and recent BTF/BTF.ext endianness functions. Further add local functions for swapping byte-order of sections containing BPF insns. Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/b47ca686d02664843fc99b96262fe3259650bc43.1726475448.git.tony.ambardar@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-04libbpf: Support opening bpf objects of either endiannessTony Ambardar2-9/+52
Allow bpf_object__open() to access files of either endianness, and convert included BPF programs to native byte-order in-memory for introspection. Loading BPF objects of non-native byte-order is still disallowed however. Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/26353c1a1887a54400e1acd6c138fa90c99cdd40.1726475448.git.tony.ambardar@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-04libbpf: Support BTF.ext loading and output in either endiannessTony Ambardar4-57/+253
Support for handling BTF data of either endianness was added in [1], but did not include BTF.ext data for lack of use cases. Later, support for static linking [2] provided a use case, but this feature and later ones were restricted to native-endian usage. Add support for BTF.ext handling in either endianness. Convert BTF.ext data to native endianness when read into memory for further processing, and support raw data access that restores the original byte-order for output. Add internal header functions for byte-swapping func, line, and core info records. Add new API functions btf_ext__endianness() and btf_ext__set_endianness() for query and setting byte-order, as already exist for BTF data. [1] 3289959b97ca ("libbpf: Support BTF loading and raw data output in both endianness") [2] 8fd27bf69b86 ("libbpf: Add BPF static linker BTF and BTF.ext support") Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/133407ab20e0dd5c07cab2a6fa7879dee1ffa4bc.1726475448.git.tony.ambardar@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-04libbpf: Fix output .symtab byte-order during linkingTony Ambardar1-0/+2
Object linking output data uses the default ELF_T_BYTE type for '.symtab' section data, which disables any libelf-based translation. Explicitly set the ELF_T_SYM type for output to restore libelf's byte-order conversion, noting that input '.symtab' data is already correctly translated. Fixes: faf6ed321cf6 ("libbpf: Add BPF static linker APIs") Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/87868bfeccf3f51aec61260073f8778e9077050a.1726475448.git.tony.ambardar@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-04libbpf: Fix header comment typos for BTF.extTony Ambardar1-2/+2
Mention struct btf_ext_info_sec rather than non-existent btf_sec_func_info in BTF.ext struct documentation. Signed-off-by: Tony Ambardar <tony.ambardar@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/cde65e01a5f2945c578485fab265ef711e2daeb6.1726475448.git.tony.ambardar@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
generated by cgit v1.2.3 (git 2.39.0) at 2025-05-03 20:07:38 +0300