kernel/linux.git/tools/bpf/bpftool/link.c, branch v6.2.2

libbpf: Hashmap interface update to allow both long and void* keys/values

2022-11-10T04:45:14+00:00

An update for libbpf's hashmap interface from void* -> void* to a polymorphic one, allowing both long and void* keys and values. This simplifies many use cases in libbpf as hashmaps there are mostly integer to integer. Perf copies hashmap implementation from libbpf and has to be updated as well. Changes to libbpf, selftests/bpf and perf are packed as a single commit to avoid compilation issues with any future bisect. Polymorphic interface is acheived by hiding hashmap interface functions behind auxiliary macros that take care of necessary type casts, for example: #define hashmap_cast_ptr(p) \ ({ \ _Static_assert((p) == NULL || sizeof(*(p)) == sizeof(long),\ #p " pointee should be a long-sized integer or a pointer"); \ (long *)(p); \ }) bool hashmap_find(const struct hashmap *map, long key, long *value); #define hashmap__find(map, key, value) \ hashmap_find((map), (long)(key), hashmap_cast_ptr(value)) - hashmap__find macro casts key and value parameters to long and long* respectively - hashmap_cast_ptr ensures that value pointer points to a memory of appropriate size. This hack was suggested by Andrii Nakryiko in [1]. This is a follow up for [2]. [1] https://lore.kernel.org/bpf/CAEf4BzZ8KFneEJxFAaNCCFPGqp20hSpS2aCj76uRk3-qZUH5xg@mail.gmail.com/ [2] https://lore.kernel.org/bpf/af1facf9-7bc8-8a3d-0db4-7b3f333589a2@meta.com/T/#m65b28f1d6d969fcd318b556db6a3ad499a42607d Signed-off-by: Eduard Zingerman Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221109142611.879983-2-eddyz87@gmail.com

bpftool: Show parameters of BPF task iterators.

2022-09-28T23:30:08+00:00

Show tid or pid of iterators if giving an argument of tid or pid For example, the command `bpftool link list` may list following lines. 1: iter prog 2 target_name bpf_map 2: iter prog 3 target_name bpf_prog 33: iter prog 225 target_name task_file tid 1644 pids test_progs(1644) Link 33 is a task_file iterator with tid 1644. For now, only targets of task, task_file and task_vma may be with tid or pid to filter out tasks other than those belonging to a process (pid) or a thread (tid). Signed-off-by: Kui-Feng Lee Signed-off-by: Andrii Nakryiko Acked-by: Quentin Monnet Acked-by: Yonghong Song Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20220926184957.208194-6-kuifeng@fb.com

bpftool: Add support for querying cgroup_iter link

2022-08-30T18:02:03+00:00

Support dumping info of a cgroup_iter link. This includes showing the cgroup's id and the order for walking the cgroup hierarchy. Example output is as follows: > bpftool link show 1: iter prog 2 target_name bpf_map 2: iter prog 3 target_name bpf_prog 3: iter prog 12 target_name cgroup cgroup_id 72 order self_only > bpftool -p link show [{ "id": 1, "type": "iter", "prog_id": 2, "target_name": "bpf_map" },{ "id": 2, "type": "iter", "prog_id": 3, "target_name": "bpf_prog" },{ "id": 3, "type": "iter", "prog_id": 12, "target_name": "cgroup", "cgroup_id": 72, "order": "self_only" } ] Signed-off-by: Hao Luo Reviewed-by: Quentin Monnet Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20220829231828.1016835-1-haoluo@google.com Signed-off-by: Martin KaFai Lau

bpftool: Use libbpf_bpf_link_type_str

2022-06-02T23:26:38+00:00

This change switches bpftool over to using the recently introduced libbpf_bpf_link_type_str function instead of maintaining its own string representation for the bpf_link_type enum. Signed-off-by: Daniel Müller Signed-off-by: Andrii Nakryiko Acked-by: Quentin Monnet Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20220523230428.3077108-13-deso@posteo.net

bpftool: Use libbpf_bpf_attach_type_str

2022-06-02T23:26:30+00:00

This change switches bpftool over to using the recently introduced libbpf_bpf_attach_type_str function instead of maintaining its own string representation for the bpf_attach_type enum. Note that contrary to other enum types, the variant names that bpftool maps bpf_attach_type to do not adhere a simple to follow rule. With bpf_prog_type, for example, the textual representation can easily be inferred by stripping the BPF_PROG_TYPE_ prefix and lowercasing the remaining string. bpf_attach_type violates this rule for various variants. We decided to fix up this deficiency with this change, meaning that bpftool uses the same textual representations as libbpf. Supporting tests, completion scripts, and man pages have been adjusted accordingly. However, we did add support for accepting (the now undocumented) original attach type names when they are provided by users. For the test (test_bpftool_synctypes.py), I have removed the enum representation checks, because we no longer mirror the various enum variant names in bpftool source code. For the man page, help text, and completion script checks we are now using enum definitions from uapi/linux/bpf.h as the source of truth directly. Signed-off-by: Daniel Müller Signed-off-by: Andrii Nakryiko Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20220523230428.3077108-10-deso@posteo.net

bpftool: Use libbpf_bpf_prog_type_str

2022-06-02T23:26:18+00:00

This change switches bpftool over to using the recently introduced libbpf_bpf_prog_type_str function instead of maintaining its own string representation for the bpf_prog_type enum. Signed-off-by: Daniel Müller Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20220523230428.3077108-4-deso@posteo.net

bpf, x86: Generate trampolines from bpf_tramp_links

2022-05-11T00:50:40+00:00

Replace struct bpf_tramp_progs with struct bpf_tramp_links to collect struct bpf_tramp_link(s) for a trampoline. struct bpf_tramp_link extends bpf_link to act as a linked list node. arch_prepare_bpf_trampoline() accepts a struct bpf_tramp_links to collects all bpf_tramp_link(s) that a trampoline should call. Change BPF trampoline and bpf_struct_ops to pass bpf_tramp_links instead of bpf_tramp_progs. Signed-off-by: Kui-Feng Lee Signed-off-by: Alexei Starovoitov Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220510205923.3206889-2-kuifeng@fb.com

bpftool: Add missing link types

2022-04-04T21:54:34+00:00

Will display the link type names in bpftool link show output Signed-off-by: Milan Landaverde Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220331154555.422506-3-milan@mdaverde.com

bpftool: Fix error check when calling hashmap__new()

2022-01-13T01:01:36+00:00

hashmap__new() encodes errors with ERR_PTR(), hence it's not valid to check the returned pointer against NULL and IS_ERR() has to be used instead. libbpf_get_error() can't be used in this case as hashmap__new() is not part of the public libbpf API and it'll continue using ERR_PTR() after libbpf 1.0. Fixes: 8f184732b60b ("bpftool: Switch to libbpf's hashmap for pinned paths of BPF objects") Fixes: 2828d0d75b73 ("bpftool: Switch to libbpf's hashmap for programs/maps in BTF listing") Fixes: d6699f8e0f83 ("bpftool: Switch to libbpf's hashmap for PIDs/names references") Signed-off-by: Mauricio Vásquez Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20220107152620.192327-2-mauricio@kinvolk.io

bpftool: Switch to libbpf's hashmap for PIDs/names references

2021-10-26T00:31:39+00:00

In order to show PIDs and names for processes holding references to BPF programs, maps, links, or BTF objects, bpftool creates hash maps to store all relevant information. This commit is part of a set that transitions from the kernel's hash map implementation to the one coming with libbpf. The motivation is to make bpftool less dependent of kernel headers, to ease the path to a potential out-of-tree mirror, like libbpf has. This is the third and final step of the transition, in which we convert the hash maps used for storing the information about the processes holding references to BPF objects (programs, maps, links, BTF), and at last we drop the inclusion of tools/include/linux/hashtable.h. Note: Checkpatch complains about the use of __weak declarations, and the missing empty lines after the bunch of empty function declarations when compiling without the BPF skeletons (none of these were introduced in this patch). We want to keep things as they are, and the reports should be safe to ignore. Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211023205154.6710-6-quentin@isovalent.com