kernel/linux.git/tools/lib/bpf/bpf.c, branch v6.3.3

libbpf: Introduce bpf_{btf,link,map,prog}_get_info_by_fd()

2023-02-16T23:32:36+00:00

These are type-safe wrappers around bpf_obj_get_info_by_fd(). They found one problem in selftests, and are also useful for adding Memory Sanitizer annotations. Signed-off-by: Ilya Leoshkevich Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230214231221.249277-2-iii@linux.ibm.com

libbpf: Introduce bpf_link_get_fd_by_id_opts()

2022-10-10T23:49:20+00:00

Introduce bpf_link_get_fd_by_id_opts(), for symmetry with bpf_map_get_fd_by_id_opts(), to let the caller pass the newly introduced data structure bpf_get_fd_by_id_opts. Keep the existing bpf_link_get_fd_by_id(), and call bpf_link_get_fd_by_id_opts() with NULL as opts argument, to prevent setting open_flags. Currently, the kernel does not support non-zero open_flags for bpf_link_get_fd_by_id_opts(), and a call with them will result in an error returned by the bpf() system call. The caller should always pass zero open_flags. Signed-off-by: Roberto Sassu Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221006110736.84253-6-roberto.sassu@huaweicloud.com

libbpf: Introduce bpf_btf_get_fd_by_id_opts()

2022-10-10T23:49:20+00:00

Introduce bpf_btf_get_fd_by_id_opts(), for symmetry with bpf_map_get_fd_by_id_opts(), to let the caller pass the newly introduced data structure bpf_get_fd_by_id_opts. Keep the existing bpf_btf_get_fd_by_id(), and call bpf_btf_get_fd_by_id_opts() with NULL as opts argument, to prevent setting open_flags. Currently, the kernel does not support non-zero open_flags for bpf_btf_get_fd_by_id_opts(), and a call with them will result in an error returned by the bpf() system call. The caller should always pass zero open_flags. Signed-off-by: Roberto Sassu Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221006110736.84253-5-roberto.sassu@huaweicloud.com

libbpf: Introduce bpf_prog_get_fd_by_id_opts()

2022-10-10T23:49:20+00:00

Introduce bpf_prog_get_fd_by_id_opts(), for symmetry with bpf_map_get_fd_by_id_opts(), to let the caller pass the newly introduced data structure bpf_get_fd_by_id_opts. Keep the existing bpf_prog_get_fd_by_id(), and call bpf_prog_get_fd_by_id_opts() with NULL as opts argument, to prevent setting open_flags. Currently, the kernel does not support non-zero open_flags for bpf_prog_get_fd_by_id_opts(), and a call with them will result in an error returned by the bpf() system call. The caller should always pass zero open_flags. Signed-off-by: Roberto Sassu Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221006110736.84253-4-roberto.sassu@huaweicloud.com

libbpf: Introduce bpf_get_fd_by_id_opts and bpf_map_get_fd_by_id_opts()

2022-10-10T23:49:20+00:00

Define a new data structure called bpf_get_fd_by_id_opts, with the member open_flags, to be used by callers of the _opts variants of bpf_*_get_fd_by_id() to specify the permissions needed for the file descriptor to be obtained. Also, introduce bpf_map_get_fd_by_id_opts(), to let the caller pass a bpf_get_fd_by_id_opts structure. Finally, keep the existing bpf_map_get_fd_by_id(), and call bpf_map_get_fd_by_id_opts() with NULL as opts argument, to request read-write permissions (current behavior). Signed-off-by: Roberto Sassu Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221006110736.84253-3-roberto.sassu@huaweicloud.com

libbpf: Clean up deprecated and legacy aliases

2022-08-17T20:42:56+00:00

Remove three missed deprecated APIs that were aliased to new APIs: bpf_object__unload, bpf_prog_attach_xattr and btf__load. Also move legacy API libbpf_find_kernel_btf (aliased to btf__load_vmlinux_btf) into libbpf_legacy.h. Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Hao Luo Link: https://lore.kernel.org/bpf/20220816001929.369487-4-andrii@kernel.org

libbpf: Streamline bpf_attr and perf_event_attr initialization

2022-08-17T20:42:10+00:00

Make sure that entire libbpf code base is initializing bpf_attr and perf_event_attr with memset(0). Also for bpf_attr make sure we clear and pass to kernel only relevant parts of bpf_attr. bpf_attr is a huge union of independent sub-command attributes, so there is no need to clear and pass entire union bpf_attr, which over time grows quite a lot and for most commands this growth is completely irrelevant. Few cases where we were relying on compiler initialization of BPF UAPI structs (like bpf_prog_info, bpf_map_info, etc) with `= {};` were switched to memset(0) pattern for future-proofing. Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Hao Luo Link: https://lore.kernel.org/bpf/20220816001929.369487-3-andrii@kernel.org

libbpf: Making bpf_prog_load() ignore name if kernel doesn't support

2022-08-15T21:58:20+00:00

Similar with commit 10b62d6a38f7 ("libbpf: Add names for auxiliary maps"), let's make bpf_prog_load() also ignore name if kernel doesn't support program name. To achieve this, we need to call sys_bpf_prog_load() directly in probe_kern_prog_name() to avoid circular dependency. sys_bpf_prog_load() also need to be exported in the libbpf_internal.h file. Signed-off-by: Hangbin Liu Signed-off-by: Andrii Nakryiko Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20220813000936.6464-1-liuhangbin@gmail.com

libbpf: Add names for auxiliary maps

2022-08-11T22:12:38+00:00

The bpftool self-created maps can appear in final map show output due to deferred removal in kernel. These maps don't have a name, which would make users confused about where it comes from. With a libbpf_ prefix name, users could know who created these maps. It also could make some tests (like test_offload.py, which skip base maps without names as a workaround) filter them out. Kernel adds bpf prog/map name support in the same merge commit fadad670a8ab ("Merge branch 'bpf-extend-info'"). So we can also use kernel_supports(NULL, FEAT_PROG_NAME) to check if kernel supports map name. As discussed [1], Let's make bpf_map_create accept non-null name string, and silently ignore the name if kernel doesn't support. [1] https://lore.kernel.org/bpf/CAEf4BzYL1TQwo1231s83pjTdFPk9XWWhfZC5=KzkU-VO0k=0Ug@mail.gmail.com/ Signed-off-by: Hangbin Liu Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220811034020.529685-1-liuhangbin@gmail.com

libbpf: Add bpf_obj_get_opts()

2022-07-29T22:30:06+00:00

Add an extensible variant of bpf_obj_get() capable of setting the `file_flags` parameter. This parameter is needed to enable unprivileged access to BPF maps. Without a method like this, users must manually make the syscall. Signed-off-by: Joe Burton Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220729202727.3311806-1-jevburton.kernel@gmail.com