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12 dayslibbpf: Fix -Wdiscarded-qualifiers under C23Mikhail Gavrilov
glibc ≥ 2.42 (GCC 15) defaults to -std=gnu23, which promotes -Wdiscarded-qualifiers to an error. In C23, strstr() and strchr() return "const char *". Change variable types to const char * where the pointers are never modified (res, sym_sfx, next_path). Suggested-by: Florian Weimer <fweimer@redhat.com> Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> Link: https://lore.kernel.org/r/20251206092825.1471385-1-mikhail.v.gavrilov@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-12-03Merge tag 'bpf-next-6.19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Pull bpf updates from Alexei Starovoitov: - Convert selftests/bpf/test_tc_edt and test_tc_tunnel from .sh to test_progs runner (Alexis Lothoré) - Convert selftests/bpf/test_xsk to test_progs runner (Bastien Curutchet) - Replace bpf memory allocator with kmalloc_nolock() in bpf_local_storage (Amery Hung), and in bpf streams and range tree (Puranjay Mohan) - Introduce support for indirect jumps in BPF verifier and x86 JIT (Anton Protopopov) and arm64 JIT (Puranjay Mohan) - Remove runqslower bpf tool (Hoyeon Lee) - Fix corner cases in the verifier to close several syzbot reports (Eduard Zingerman, KaFai Wan) - Several improvements in deadlock detection in rqspinlock (Kumar Kartikeya Dwivedi) - Implement "jmp" mode for BPF trampoline and corresponding DYNAMIC_FTRACE_WITH_JMP. It improves "fexit" program type performance from 80 M/s to 136 M/s. With Steven's Ack. (Menglong Dong) - Add ability to test non-linear skbs in BPF_PROG_TEST_RUN (Paul Chaignon) - Do not let BPF_PROG_TEST_RUN emit invalid GSO types to stack (Daniel Borkmann) - Generalize buildid reader into bpf_dynptr (Mykyta Yatsenko) - Optimize bpf_map_update_elem() for map-in-map types (Ritesh Oedayrajsingh Varma) - Introduce overwrite mode for BPF ring buffer (Xu Kuohai) * tag 'bpf-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (169 commits) bpf: optimize bpf_map_update_elem() for map-in-map types bpf: make kprobe_multi_link_prog_run always_inline selftests/bpf: do not hardcode target rate in test_tc_edt BPF program selftests/bpf: remove test_tc_edt.sh selftests/bpf: integrate test_tc_edt into test_progs selftests/bpf: rename test_tc_edt.bpf.c section to expose program type selftests/bpf: Add success stats to rqspinlock stress test rqspinlock: Precede non-head waiter queueing with AA check rqspinlock: Disable spinning for trylock fallback rqspinlock: Use trylock fallback when per-CPU rqnode is busy rqspinlock: Perform AA checks immediately rqspinlock: Enclose lock/unlock within lock entry acquisitions bpf: Remove runqslower tool selftests/bpf: Remove usage of lsm/file_alloc_security in selftest bpf: Disable file_alloc_security hook bpf: check for insn arrays in check_ptr_alignment bpf: force BPF_F_RDONLY_PROG on insn array creation bpf: Fix exclusive map memory leak selftests/bpf: Make CS length configurable for rqspinlock stress test selftests/bpf: Add lock wait time stats to rqspinlock stress test ...
2025-11-17tools: Remove s390 compat supportHeiko Carstens
Remove s390 compat support from everything within tools, since s390 compat support will be removed from the kernel. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Weißschuh <linux@weissschuh.net> # tools/nolibc selftests/nolibc Reviewed-by: Thomas Weißschuh <linux@weissschuh.net> # selftests/vDSO Acked-by: Alexei Starovoitov <ast@kernel.org> # bpf bits Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-05libbpf: support llvm-generated indirect jumpsAnton Protopopov
For v4 instruction set LLVM is allowed to generate indirect jumps for switch statements and for 'goto *rX' assembly. Every such a jump will be accompanied by necessary metadata, e.g. (`llvm-objdump -Sr ...`): 0: r2 = 0x0 ll 0000000000000030: R_BPF_64_64 BPF.JT.0.0 Here BPF.JT.1.0 is a symbol residing in the .jumptables section: Symbol table: 4: 0000000000000000 240 OBJECT GLOBAL DEFAULT 4 BPF.JT.0.0 The -bpf-min-jump-table-entries llvm option may be used to control the minimal size of a switch which will be converted to an indirect jumps. Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20251105090410.1250500-11-a.s.protopopov@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-05libbpf: Recognize insn_array map typeAnton Protopopov
Teach libbpf about the existence of the new instruction array map. Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com> Link: https://lore.kernel.org/r/20251105090410.1250500-4-a.s.protopopov@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-04libbpf: Update the comment to remove the reference to the deprecated ↵Jianyun Gao
interface bpf_program__load(). Commit be2f2d1680df ("libbpf: Deprecate bpf_program__load() API") marked bpf_program__load() as deprecated starting with libbpf v0.6. And later in commit 146bf811f5ac ("libbpf: remove most other deprecated high-level APIs") actually removed the bpf_program__load() implementation and related old high-level APIs. This patch update the comment in bpf_program__set_attach_target() to remove the reference to the deprecated interface bpf_program__load(). Signed-off-by: Jianyun Gao <jianyungao89@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20251103120727.145965-1-jianyungao89@gmail.com
2025-10-28libbpf: Optimize the redundant code in the bpf_object__init_user_btf_maps() ↵Jianyun Gao
function. In the elf_sec_data() function, the input parameter 'scn' will be evaluated. If it is NULL, then it will directly return NULL. Therefore, the return value of the elf_sec_data() function already takes into account the case where the input parameter scn is NULL. Therefore, subsequently, the code only needs to check whether the return value of the elf_sec_data() function is NULL. Signed-off-by: Jianyun Gao <jianyungao89@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20251024080802.642189-1-jianyungao89@gmail.com
2025-10-21libbpf: fix formatting of bpf_object__append_subprog_codeAnton Protopopov
The commit 6c918709bd30 ("libbpf: Refactor bpf_object__reloc_code") added the bpf_object__append_subprog_code() with incorrect indentations. Use tabs instead. (This also makes a consequent commit better readable.) Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20251019202145.3944697-14-a.s.protopopov@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-10-01libbpf: move libbpf_sha256() implementation into libbpf_utils.cAndrii Nakryiko
Move sha256 implementation out of already large and unwieldy libbpf.c into libbpf_utils.c where we'll keep reusable helpers. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20251001171326.3883055-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com>
2025-10-01libbpf: move libbpf_errstr() into libbpf_utils.cAndrii Nakryiko
Get rid of str_err.{c,h} by moving implementation of libbpf_errstr() into libbpf_utils.c and declarations into libbpf_internal.h. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20251001171326.3883055-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com>
2025-10-01libbpf: remove unused libbpf_strerror_r and STRERR_BUFSIZEAndrii Nakryiko
libbpf_strerror_r() is not exposed as public API and neither is it used inside libbpf itself. Remove it altogether. Same for STRERR_BUFSIZE, it's just an orphaned leftover constant which we missed to clean up some time earlier. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20251001171326.3883055-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com>
2025-09-28libbpf: Replace AF_ALG with open coded SHA-256Eric Biggers
Reimplement libbpf_sha256() using some basic SHA-256 C code. This eliminates the newly-added dependency on AF_ALG, which is a problematic UAPI that is not supported by all kernels. Make libbpf_sha256() return void, since it can no longer fail. This simplifies some callers. Also drop the unnecessary 'sha_out_sz' parameter. Finally, also fix the typo in "compute_sha_udpate_offsets". Fixes: c297fe3e9f99 ("libbpf: Implement SHA256 internal helper") Signed-off-by: Eric Biggers <ebiggers@kernel.org> Link: https://lore.kernel.org/r/20250928003833.138407-1-ebiggers@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-09-26libbpf: Fix error when st-prefix_ops and ops from differ btfD. Wythe
When a module registers a struct_ops, the struct_ops type and its corresponding map_value type ("bpf_struct_ops_") may reside in different btf objects, here are four possible case: +--------+---------------+-------------+---------------------------------+ | |bpf_struct_ops_| xxx_ops | | +--------+---------------+-------------+---------------------------------+ | case 0 | btf_vmlinux | btf_vmlinux | be used and reg only in vmlinux | +--------+---------------+-------------+---------------------------------+ | case 1 | btf_vmlinux | mod_btf | INVALID | +--------+---------------+-------------+---------------------------------+ | case 2 | mod_btf | btf_vmlinux | reg in mod but be used both in | | | | | vmlinux and mod. | +--------+---------------+-------------+---------------------------------+ | case 3 | mod_btf | mod_btf | be used and reg only in mod | +--------+---------------+-------------+---------------------------------+ Currently we figure out the mod_btf by searching with the struct_ops type, which makes it impossible to figure out the mod_btf when the struct_ops type is in btf_vmlinux while it's corresponding map_value type is in mod_btf (case 2). The fix is to use the corresponding map_value type ("bpf_struct_ops_") as the lookup anchor instead of the struct_ops type to figure out the `btf` and `mod_btf` via find_ksym_btf_id(), and then we can locate the kern_type_id via btf__find_by_name_kind() with the `btf` we just obtained from find_ksym_btf_id(). With this change the lookup obtains the correct btf and mod_btf for case 2, preserves correct behavior for other valid cases, and still fails as expected for the invalid scenario (case 1). Fixes: 590a00888250 ("bpf: libbpf: Add STRUCT_OPS support") Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/bpf/20250926071751.108293-1-alibuda@linux.alibaba.com
2025-09-18libbpf: Support exclusive map creationKP Singh
Implement setters and getters that allow map to be registered as exclusive to the specified program. The registration should be done before the exclusive program is loaded. Signed-off-by: KP Singh <kpsingh@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20250914215141.15144-5-kpsingh@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-09-18libbpf: Implement SHA256 internal helperKP Singh
Use AF_ALG sockets to not have libbpf depend on OpenSSL. The helper is used for the loader generation code to embed the metadata hash in the loader program and also by the bpf_map__make_exclusive API to calculate the hash of the program the map is exclusive to. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/r/20250914215141.15144-4-kpsingh@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-08-15libbpf: Fix reuse of DEVMAPYureka Lilian
Previously, re-using pinned DEVMAP maps would always fail, because get_map_info on a DEVMAP always returns flags with BPF_F_RDONLY_PROG set, but BPF_F_RDONLY_PROG being set on a map during creation is invalid. Thus, ignore the BPF_F_RDONLY_PROG flag in the flags returned from get_map_info when checking for compatibility with an existing DEVMAP. The same problem is handled in a third-party ebpf library: - https://github.com/cilium/ebpf/issues/925 - https://github.com/cilium/ebpf/pull/930 Fixes: 0cdbb4b09a06 ("devmap: Allow map lookups from eBPF") Signed-off-by: Yureka Lilian <yuka@yuka.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250814180113.1245565-3-yuka@yuka.dev
2025-08-07libbpf: Add the ability to suppress perf event enablementIlya Leoshkevich
Automatically enabling a perf event after attaching a BPF prog to it is not always desirable. Add a new "dont_enable" field to struct bpf_perf_event_opts. While introducing "enable" instead would be nicer in that it would avoid a double negation in the implementation, it would make DECLARE_LIBBPF_OPTS() less efficient. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Suggested-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Thomas Richter <tmricht@linux.ibm.com> Co-developed-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/r/20250806162417.19666-2-iii@linux.ibm.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-07-31libbpf: Avoid possible use of uninitialized mod_lenAchill Gilgenast
Though mod_len is only read when mod_name != NULL and both are initialized together, gcc15 produces a warning with -Werror=maybe-uninitialized: libbpf.c: In function 'find_kernel_btf_id.constprop': libbpf.c:10100:33: error: 'mod_len' may be used uninitialized [-Werror=maybe-uninitialized] 10100 | if (mod_name && strncmp(mod->name, mod_name, mod_len) != 0) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ libbpf.c:10070:21: note: 'mod_len' was declared here 10070 | int ret, i, mod_len; | ^~~~~~~ Silence the false positive. Signed-off-by: Achill Gilgenast <fossdd@pwned.life> Acked-by: Yonghong Song <yonghong.song@linux.dev> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20250729094611.2065713-1-fossdd@pwned.life Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-07-18libbpf: Verify that arena map exists when adding arena relocationsEduard Zingerman
Fuzzer reported a memory access error in bpf_program__record_reloc() that happens when: - ".addr_space.1" section exists - there is a relocation referencing this section - there are no arena maps defined in BTF. Sanity checks for maps existence are already present in bpf_program__record_reloc(), hence this commit adds another one. [1] https://github.com/libbpf/libbpf/actions/runs/16375110681/job/46272998064 Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250718222059.281526-1-eddyz87@gmail.com
2025-07-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf after rc6Alexei Starovoitov
Cross-merge BPF and other fixes after downstream PR. No conflicts. Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-07-18libbpf: Fix warning in calloc() usageMatteo Croce
When compiling libbpf with some compilers, this warning is triggered: libbpf.c: In function ‘bpf_object__gen_loader’: libbpf.c:9209:28: error: ‘calloc’ sizes specified with ‘sizeof’ in the earlier argument and not in the later argument [-Werror=calloc-transposed-args] 9209 | gen = calloc(sizeof(*gen), 1); | ^ libbpf.c:9209:28: note: earlier argument should specify number of elements, later size of each element Fix this by inverting the calloc() arguments. Signed-off-by: Matteo Croce <teknoraver@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20250717200337.49168-1-technoboy85@gmail.com
2025-07-17libbpf: Fix handling of BPF arena relocationsAndrii Nakryiko
Initial __arena global variable support implementation in libbpf contains a bug: it remembers struct bpf_map pointer for arena, which is used later on to process relocations. Recording this pointer is problematic because map pointers are not stable during ELF relocation collection phase, as an array of struct bpf_map's can be reallocated, invalidating all the pointers. Libbpf is dealing with similar issues by using a stable internal map index, though for BPF arena map specifically this approach wasn't used due to an oversight. The resulting behavior is non-deterministic issue which depends on exact layout of ELF object file, number of actual maps, etc. We didn't hit this until very recently, when this bug started triggering crash in BPF CI when validating one of sched-ext BPF programs. The fix is rather straightforward: we just follow an established pattern of remembering map index (just like obj->kconfig_map_idx, for example) instead of `struct bpf_map *`, and resolving index to a pointer at the point where map information is necessary. While at it also add debug-level message for arena-related relocation resolution information, which we already have for all other kinds of maps. Fixes: 2e7ba4f8fd1f ("libbpf: Recognize __arena global variables.") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20250718001009.610955-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-06-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf after rc3Alexei Starovoitov
Cross-merge BPF, perf and other fixes after downstream PRs. It restores BPF CI to green after critical fix commit bc4394e5e79c ("perf: Fix the throttle error of some clock events") No conflicts. Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-06-25libbpf: Fix possible use-after-free for externsAdin Scannell
The `name` field in `obj->externs` points into the BTF data at initial open time. However, some functions may invalidate this after opening and before loading (e.g. `bpf_map__set_value_size`), which results in pointers into freed memory and undefined behavior. The simplest solution is to simply `strdup` these strings, similar to the `essent_name`, and free them at the same time. In order to test this path, the `global_map_resize` BPF selftest is modified slightly to ensure the presence of an extern, which causes this test to fail prior to the fix. Given there isn't an obvious API or error to test against, I opted to add this to the existing test as an aspect of the resizing feature rather than duplicate the test. Fixes: 9d0a23313b1a ("libbpf: Add capability for resizing datasec maps") Signed-off-by: Adin Scannell <amscanne@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250625050215.2777374-1-amscanne@meta.com
2025-06-09libbpf: Support link-based cgroup attach with optionsYonghong Song
Currently libbpf supports bpf_program__attach_cgroup() with signature: LIBBPF_API struct bpf_link * bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd); To support mprog style attachment, additionsl fields like flags, relative_{fd,id} and expected_revision are needed. Add a new API: LIBBPF_API struct bpf_link * bpf_program__attach_cgroup_opts(const struct bpf_program *prog, int cgroup_fd, const struct bpf_cgroup_opts *opts); where bpf_cgroup_opts contains all above needed fields. Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250606163146.2429212-1-yonghong.song@linux.dev
2025-05-14libbpf: Check bpf_map_skeleton link for NULLMykyta Yatsenko
Avoid dereferencing bpf_map_skeleton's link field if it's NULL. If BPF map skeleton is created with the size, that indicates containing link field, but the field was not actually initialized with valid bpf_link pointer, libbpf crashes. This may happen when using libbpf-rs skeleton. Skeleton loading may still progress, but user needs to attach struct_ops map separately. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250514113220.219095-1-mykyta.yatsenko5@gmail.com
2025-04-25Use thread-safe function pointer in libbpf_printJonathan Wiepert
This patch fixes a thread safety bug where libbpf_print uses the global variable storing the print function pointer rather than the local variable that had the print function set via __atomic_load_n. Fixes: f1cb927cdb62 ("libbpf: Ensure print callback usage is thread-safe") Signed-off-by: Jonathan Wiepert <jonathan.wiepert@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Mykyta Yatsenko <mykyta.yatsenko5@gmail.com> Link: https://lore.kernel.org/bpf/20250424221457.793068-1-jonathan.wiepert@gmail.com
2025-04-25libbpf: Remove sample_period init in perf_bufferTao Chen
It seems that sample_period is not used in perf buffer. Actually, only wakeup_events are meaningful to enable events aggregation for wakeup notification. Remove sample_period setting code to avoid confusion. Fixes: fb84b8224655 ("libbpf: add perf buffer API") Signed-off-by: Tao Chen <chen.dylane@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/bpf/20250423163901.2983689-1-chen.dylane@linux.dev
2025-04-22libbpf: Fix event name too long errorFeng Yang
When the binary path is excessively long, the generated probe_name in libbpf exceeds the kernel's MAX_EVENT_NAME_LEN limit (64 bytes). This causes legacy uprobe event attachment to fail with error code -22. The fix reorders the fields to place the unique ID before the name. This ensures that even if truncation occurs via snprintf, the unique ID remains intact, preserving event name uniqueness. Additionally, explicit checks with MAX_EVENT_NAME_LEN are added to enforce length constraints. Before Fix: ./test_progs -t attach_probe/kprobe-long_name ...... libbpf: failed to add legacy kprobe event for 'bpf_testmod_looooooooooooooooooooooooooooooong_name+0x0': -EINVAL libbpf: prog 'handle_kprobe': failed to create kprobe 'bpf_testmod_looooooooooooooooooooooooooooooong_name+0x0' perf event: -EINVAL test_attach_kprobe_long_event_name:FAIL:attach_kprobe_long_event_name unexpected error: -22 test_attach_probe:PASS:uprobe_ref_ctr_cleanup 0 nsec #13/11 attach_probe/kprobe-long_name:FAIL #13 attach_probe:FAIL ./test_progs -t attach_probe/uprobe-long_name ...... libbpf: failed to add legacy uprobe event for /root/linux-bpf/bpf-next/tools/testing/selftests/bpf/test_progs:0x13efd9: -EINVAL libbpf: prog 'handle_uprobe': failed to create uprobe '/root/linux-bpf/bpf-next/tools/testing/selftests/bpf/test_progs:0x13efd9' perf event: -EINVAL test_attach_uprobe_long_event_name:FAIL:attach_uprobe_long_event_name unexpected error: -22 #13/10 attach_probe/uprobe-long_name:FAIL #13 attach_probe:FAIL After Fix: ./test_progs -t attach_probe/uprobe-long_name #13/10 attach_probe/uprobe-long_name:OK #13 attach_probe:OK Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED ./test_progs -t attach_probe/kprobe-long_name #13/11 attach_probe/kprobe-long_name:OK #13 attach_probe:OK Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED Fixes: 46ed5fc33db9 ("libbpf: Refactor and simplify legacy kprobe code") Fixes: cc10623c6810 ("libbpf: Add legacy uprobe attaching support") Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Feng Yang <yangfeng@kylinos.cn> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250417014848.59321-2-yangfeng59949@163.com
2025-04-15libbpf: Fix buffer overflow in bpf_object__init_progViktor Malik
As shown in [1], it is possible to corrupt a BPF ELF file such that arbitrary BPF instructions are loaded by libbpf. This can be done by setting a symbol (BPF program) section offset to a large (unsigned) number such that <section start + symbol offset> overflows and points before the section data in the memory. Consider the situation below where: - prog_start = sec_start + symbol_offset <-- size_t overflow here - prog_end = prog_start + prog_size prog_start sec_start prog_end sec_end | | | | v v v v .....................|################################|............ The report in [1] also provides a corrupted BPF ELF which can be used as a reproducer: $ readelf -S crash Section Headers: [Nr] Name Type Address Offset Size EntSize Flags Link Info Align ... [ 2] uretprobe.mu[...] PROGBITS 0000000000000000 00000040 0000000000000068 0000000000000000 AX 0 0 8 $ readelf -s crash Symbol table '.symtab' contains 8 entries: Num: Value Size Type Bind Vis Ndx Name ... 6: ffffffffffffffb8 104 FUNC GLOBAL DEFAULT 2 handle_tp Here, the handle_tp prog has section offset ffffffffffffffb8, i.e. will point before the actual memory where section 2 is allocated. This is also reported by AddressSanitizer: ================================================================= ==1232==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7c7302fe0000 at pc 0x7fc3046e4b77 bp 0x7ffe64677cd0 sp 0x7ffe64677490 READ of size 104 at 0x7c7302fe0000 thread T0 #0 0x7fc3046e4b76 in memcpy (/lib64/libasan.so.8+0xe4b76) #1 0x00000040df3e in bpf_object__init_prog /src/libbpf/src/libbpf.c:856 #2 0x00000040df3e in bpf_object__add_programs /src/libbpf/src/libbpf.c:928 #3 0x00000040df3e in bpf_object__elf_collect /src/libbpf/src/libbpf.c:3930 #4 0x00000040df3e in bpf_object_open /src/libbpf/src/libbpf.c:8067 #5 0x00000040f176 in bpf_object__open_file /src/libbpf/src/libbpf.c:8090 #6 0x000000400c16 in main /poc/poc.c:8 #7 0x7fc3043d25b4 in __libc_start_call_main (/lib64/libc.so.6+0x35b4) #8 0x7fc3043d2667 in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x3667) #9 0x000000400b34 in _start (/poc/poc+0x400b34) 0x7c7302fe0000 is located 64 bytes before 104-byte region [0x7c7302fe0040,0x7c7302fe00a8) allocated by thread T0 here: #0 0x7fc3046e716b in malloc (/lib64/libasan.so.8+0xe716b) #1 0x7fc3045ee600 in __libelf_set_rawdata_wrlock (/lib64/libelf.so.1+0xb600) #2 0x7fc3045ef018 in __elf_getdata_rdlock (/lib64/libelf.so.1+0xc018) #3 0x00000040642f in elf_sec_data /src/libbpf/src/libbpf.c:3740 The problem here is that currently, libbpf only checks that the program end is within the section bounds. There used to be a check `while (sec_off < sec_sz)` in bpf_object__add_programs, however, it was removed by commit 6245947c1b3c ("libbpf: Allow gaps in BPF program sections to support overriden weak functions"). Add a check for detecting the overflow of `sec_off + prog_sz` to bpf_object__init_prog to fix this issue. [1] https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md Fixes: 6245947c1b3c ("libbpf: Allow gaps in BPF program sections to support overriden weak functions") Reported-by: lmarch2 <2524158037@qq.com> Signed-off-by: Viktor Malik <vmalik@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Link: https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md Link: https://lore.kernel.org/bpf/20250415155014.397603-1-vmalik@redhat.com
2025-04-09libbpf: Add getters for BTF.ext func and line infoMykyta Yatsenko
Introducing new libbpf API getters for BTF.ext func and line info, namely: bpf_program__func_info bpf_program__func_info_cnt bpf_program__line_info bpf_program__line_info_cnt This change enables scenarios, when user needs to load bpf_program directly using `bpf_prog_load`, instead of higher-level `bpf_object__load`. Line and func info are required for checking BTF info in verifier; verification may fail without these fields if, for example, program calls `bpf_obj_new`. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250408234417.452565-2-mykyta.yatsenko5@gmail.com
2025-04-04libbpf: Fix implicit memfd_create() for bionicCarlos Llamas
Since memfd_create() is not consistently available across different bionic libc implementations, using memfd_create() directly can break some Android builds: tools/lib/bpf/linker.c:576:7: error: implicit declaration of function 'memfd_create' [-Werror,-Wimplicit-function-declaration] 576 | fd = memfd_create(filename, 0); | ^ To fix this, relocate and inline the sys_memfd_create() helper so that it can be used in "linker.c". Similar issues were previously fixed by commit 9fa5e1a180aa ("libbpf: Call memfd_create() syscall directly"). Fixes: 6d5e5e5d7ce1 ("libbpf: Extend linker API to support in-memory ELF files") Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250330211325.530677-1-cmllamas@google.com
2025-03-17libbpf: Pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_IDMykyta Yatsenko
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 Yatsenko
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 Yatsenko
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 Yatsenko
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>
2025-02-24libbpf: Fix out-of-bound readNandakumar Edamana
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
2025-02-19libbpf: Wrap libbpf API direct err with libbpf_errTao Chen
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
2025-01-17libbpf: Work around kernel inconsistently stripping '.llvm.' suffixAndrii Nakryiko
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
2025-01-10libbpf: Add unique_match option for multi kprobeYonghong Song
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
2024-12-30libbpf: Set MFD_NOEXEC_SEAL when creating memfdDaniel Xu
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>
2024-11-15libbpf: Fix memory leak in bpf_program__attach_uprobe_multiJiri Olsa
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
2024-11-11libbpf: Stringify errno in log messages in libbpf.cMykyta Yatsenko
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
2024-11-11libbpf: Add support for uprobe multi session attachJiri Olsa
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 Olsa
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
2024-10-23libbpf: move global data mmap()'ing into bpf_object__load()Andrii Nakryiko
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>
2024-10-11libbpf: never interpret subprogs in .text as entry programsAndrii Nakryiko
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>
2024-10-09libbpf: fix sym_is_subprog() logic for weak global subprogsAndrii Nakryiko
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>
2024-10-03libbpf: Support creating light skeleton of either endiannessTony Ambardar
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>
2024-10-03libbpf: Support opening bpf objects of either endiannessTony Ambardar
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>
generated by cgit v1.2.3 (git 2.25.1) at 2025-12-22 19:06:10 +0000