kernel/linux.git/tools/lib/bpf, branch v7.0-rc7

libbpf: Remove extern declaration of bpf_stream_vprintk()

2026-02-18T22:58:47+00:00

An issue was reported that building BPF program which includes both vmlinux.h and bpf_helpers.h from libbpf fails due to conflicting declarations of bpf_stream_vprintk(). Remove the extern declaration from bpf_helpers.h to address this. In order to use bpf_stream_printk() macro, BPF programs are expected to either include vmlinux.h of the kernel they are targeting, or add their own extern declaration. Reported-by: Luca Boccassi Closes: https://github.com/libbpf/libbpf/issues/947 Signed-off-by: Ihor Solodrai Link: https://lore.kernel.org/r/20260218215651.2057673-3-ihor.solodrai@linux.dev Signed-off-by: Alexei Starovoitov

bpftool: Fix truncated netlink dumps

2026-02-18T00:54:03+00:00

Netlink requires that the recv buffer used during dumps is at least min(PAGE_SIZE, 8k) (see the man page). Otherwise the messages will get truncated. Make sure bpftool follows this requirement, avoid missing information on systems with large pages. Acked-by: Quentin Monnet Fixes: 7084566a236f ("tools/bpftool: Remove libbpf_internal.h usage in bpftool") Signed-off-by: Jakub Kicinski Link: https://lore.kernel.org/r/20260217194150.734701-1-kuba@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: Delay feature gate check until object prepare time

2026-02-17T22:20:24+00:00

Commit 728ff167910e ("libbpf: Add gating for arena globals relocation feature") adds a feature gate check that loads a map and BPF program to test the running kernel supports large direct offsets for LDIMM64 instructions. This check is currently used to calculate arena symbol offsets during bpf_object__collect_relos, itself called by bpf_object_open. However, the program calling bpf_object_open may not have the permissions to load maps and programs. This is the case with the BPF selftests, where bpftool is invoked at compilation time during skeleton generation. This causes errors as the feature gate unexpectedly fails with -EPERM. Avoid this by moving all the use of the FEAT_LDIMM64_FULL_RANGE_OFF feature gate to BPF object preparation time instead. Fixes: 728ff167910e ("libbpf: Add gating for arena globals relocation feature") Signed-off-by: Emil Tsalapatis Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20260217204345.548648-3-emil@etsalapatis.com

libbpf: Do not use PROG_TYPE_TRACEPOINT program for feature gating

2026-02-17T22:17:06+00:00

Commit 728ff167910e uses a PROG_TYPE_TRACEPOINT BPF test program to check whether the running kernel supports large LDIMM64 offsets. The feature gate incorrectly assumes that the program will fail at verification time with one of two messages, depending on whether the feature is supported by the running kernel. However, PROG_TYPE_TRACEPOINT programs may fail to load before verification even starts, e.g., if the shell does not have the appropriate capabilities. Use a BPF_PROG_TYPE_SOCKET_FILTER program for the feature gate instead. Also fix two minor issues. First, ensure the log buffer for the test is initialized: Failing program load before verification led to libbpf dumping uninitialized data to stdout. Also, ensure that close() is only called for program_fd in the probe if the program load actually succeeded. The call was currently failing silently with -EBADF most of the time. Fixes: 728ff167910e ("libbpf: Add gating for arena globals relocation feature") Reported-by: Alexei Starovoitov Signed-off-by: Emil Tsalapatis Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20260217204345.548648-2-emil@etsalapatis.com

libbpf: Fix invalid write loop logic in bpf_linker__add_buf()

2026-02-13T22:14:27+00:00

Fix bpf_linker__add_buf()'s logic of copying data from memory buffer into memfd. In the event of short write not writing entire buf_sz bytes into memfd file, we'll append bytes from the beginning of buf *again* (corrupting ELF file contents) instead of correctly appending the rest of not-yet-read buf contents. Closes: https://github.com/libbpf/libbpf/issues/945 Fixes: 6d5e5e5d7ce1 ("libbpf: Extend linker API to support in-memory ELF files") Signed-off-by: Amery Hung Signed-off-by: Andrii Nakryiko Acked-by: Jiri Olsa Link: https://lore.kernel.org/bpf/20260209230134.3530521-1-ameryhung@gmail.com Signed-off-by: Alexei Starovoitov

libbpf: Add gating for arena globals relocation feature

2026-02-13T22:14:27+00:00

Add feature gating for the arena globals relocation introduced in commit c1f61171d44b. The commit depends on a previous commit in the same patchset that is absent from older kernels (12a1fe6e12db "bpf/verifier: Do not limit maximum direct offset into arena map"). Without this commit, arena globals relocation with arenas >= 512MiB fails to load and breaks libbpf's backwards compatibility. Introduce a libbpf feature to check whether the running kernel allows for full range ldimm64 offset, and only relocate arena globals if it does. Fixes: c1f61171d44b ("libbpf: Move arena globals to the end of the arena") Signed-off-by: Emil Tsalapatis Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20260210184532.255475-1-emil@etsalapatis.com Signed-off-by: Alexei Starovoitov

libbpf: add fsession support

2026-01-25T02:49:36+00:00

Add BPF_TRACE_FSESSION to libbpf. Signed-off-by: Menglong Dong Link: https://lore.kernel.org/r/20260124062008.8657-9-dongml2@chinatelecom.cn Signed-off-by: Alexei Starovoitov

bpf: Migrate bpf_stream_vprintk() to KF_IMPLICIT_ARGS

2026-01-21T00:22:38+00:00

Implement bpf_stream_vprintk with an implicit bpf_prog_aux argument, and remote bpf_stream_vprintk_impl from the kernel. Update the selftests to use the new API with implicit argument. bpf_stream_vprintk macro is changed to use the new bpf_stream_vprintk kfunc, and the extern definition of bpf_stream_vprintk_impl is replaced accordingly. Reviewed-by: Eduard Zingerman Signed-off-by: Ihor Solodrai Link: https://lore.kernel.org/r/20260120222638.3976562-11-ihor.solodrai@linux.dev Signed-off-by: Alexei Starovoitov

btf: Refactor the code by calling str_is_empty

2026-01-14T00:21:56+00:00

Calling the str_is_empty function to clarify the code and no functional changes are introduced. Signed-off-by: Donglin Peng Signed-off-by: Andrii Nakryiko Acked-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20260109130003.3313716-12-dolinux.peng@gmail.com

libbpf: Verify BTF sorting

2026-01-14T00:16:59+00:00

This patch checks whether the BTF is sorted by name in ascending order. If sorted, binary search will be used when looking up types. Signed-off-by: Donglin Peng Signed-off-by: Andrii Nakryiko Acked-by: Eduard Zingerman Link: https://lore.kernel.org/bpf/20260109130003.3313716-6-dolinux.peng@gmail.com