kernel/linux.git/tools/bpf/bpftool/map.c, branch v6.6.131

bpftool: Specify XDP Hints ifname when loading program

2023-05-23T14:55:06+00:00

Add ability to specify a network interface used to resolve XDP hints kfuncs when loading program through bpftool. Usage: bpftool prog load [...] xdpmeta_dev Writing just 'dev ' instead of 'xdpmeta_dev' is a very probable mistake that results in not very descriptive errors, so 'bpftool prog load [...] dev ' syntax becomes deprecated, followed by 'bpftool map create [...] dev ' for consistency. Now, to offload program, execute: bpftool prog load [...] offload_dev To offload map: bpftool map create [...] offload_dev 'dev ' still performs offloading in the commands above, but now triggers a warning and is excluded from bash completion. 'xdpmeta_dev' and 'offload_dev' are mutually exclusive options, because 'xdpmeta_dev' basically makes a program device-bound without loading it onto the said device. For now, offloaded programs cannot use XDP hints [0], but if this changes, using 'offload_dev ' should cover this case. [0] https://lore.kernel.org/bpf/a5a636cc-5b03-686f-4be0-000383b05cfc@linux.dev Signed-off-by: Larysa Zaremba Signed-off-by: Daniel Borkmann Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20230517160103.1088185-1-larysa.zaremba@intel.com

bpftool: Dump map id instead of value for map_of_maps types

2023-04-27T20:26:34+00:00

When using `bpftool map dump` with map_of_maps, it is usually more convenient to show the inner map id instead of raw value. We are changing the plain print behavior to show inner_map_id instead of hex value, this would help with quick look up of inner map with `bpftool map dump id `. To avoid disrupting scripted behavior, we will add a new `inner_map_id` field to json output instead of replacing value. plain print: ``` $ bpftool map dump id 138 Without Patch: key: fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00 05 27 16 06 00 value: 8b 00 00 00 Found 1 element With Patch: key: fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00 05 27 16 06 00 inner_map_id: 139 Found 1 element ``` json print: ``` $ bpftool -p map dump id 567 Without Patch: [{ "key": ["0xc0","0x00","0x02","0x05","0x27","0x16","0x06","0x00" ], "value": ["0x38","0x02","0x00","0x00" ] } ] With Patch: [{ "key": ["0xc0","0x00","0x02","0x05","0x27","0x16","0x06","0x00" ], "value": ["0x38","0x02","0x00","0x00" ], "inner_map_id": 568 } ] ``` Signed-off-by: Xueming Feng Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20230427120313.43574-1-kuro@kuroa.me Signed-off-by: Martin KaFai Lau

bpftool: Use bpf_{btf,link,map,prog}_get_info_by_fd()

2023-02-16T23:32:45+00:00

Use the new type-safe wrappers around bpf_obj_get_info_by_fd(). Split the bpf_obj_get_info_by_fd() call in build_btf_type_table() in two, since knowing the type helps with the Memory Sanitizer. Improve map_parse_fd_and_info() type safety by using struct bpf_map_info * instead of void * for info. Signed-off-by: Ilya Leoshkevich Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20230214231221.249277-4-iii@linux.ibm.com

bpftool: remove function free_btf_vmlinux()

2022-11-21T00:17:46+00:00

The function contains a single btf__free() call which can be inlined. Credits to Yonghong Song. Signed-off-by: Sahid Orentino Ferdjaoui Acked-by: Yonghong Song Suggested-by: Yonghong Song Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/r/20221120112515.38165-6-sahid.ferdjaoui@industrialdiscipline.com Signed-off-by: Alexei Starovoitov

bpftool: clean-up usage of libbpf_get_error()

2022-11-21T00:17:46+00:00

bpftool is now totally compliant with libbpf 1.0 mode and is not expected to be compiled with pre-1.0, let's clean-up the usage of libbpf_get_error(). The changes stay aligned with returned errors always negative. - In tools/bpf/bpftool/btf.c This fixes an uninitialized local variable `err` in function do_dump() because it may now be returned without having been set. - This also removes the checks on NULL pointers before calling btf__free() because that function already does the check. Signed-off-by: Sahid Orentino Ferdjaoui Link: https://lore.kernel.org/r/20221120112515.38165-5-sahid.ferdjaoui@industrialdiscipline.com Signed-off-by: Alexei Starovoitov

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: Support new cgroup local storage

2022-10-26T06:19:19+00:00

Add support for new cgroup local storage Acked-by: Quentin Monnet Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20221026042901.674177-1-yhs@fb.com Signed-off-by: Alexei Starovoitov

bpftool: Remove asserts from JIT disassembler

2022-10-25T17:11:56+00:00

The JIT disassembler in bpftool is the only components (with the JSON writer) using asserts to check the return values of functions. But it does not do so in a consistent way, and diasm_print_insn() returns no value, although sometimes the operation failed. Remove the asserts, and instead check the return values, print messages on errors, and propagate the error to the caller from prog.c. Remove the inclusion of assert.h from jit_disasm.c, and also from map.c where it is unused. Signed-off-by: Quentin Monnet Tested-by: Niklas Söderlund Acked-by: Song Liu Link: https://lore.kernel.org/r/20221025150329.97371-3-quentin@isovalent.com Signed-off-by: Alexei Starovoitov

bpf: Define new BPF_MAP_TYPE_USER_RINGBUF map type

2022-09-21T23:24:17+00:00

We want to support a ringbuf map type where samples are published from user-space, to be consumed by BPF programs. BPF currently supports a kernel -> user-space circular ring buffer via the BPF_MAP_TYPE_RINGBUF map type. We'll need to define a new map type for user-space -> kernel, as none of the helpers exported for BPF_MAP_TYPE_RINGBUF will apply to a user-space producer ring buffer, and we'll want to add one or more helper functions that would not apply for a kernel-producer ring buffer. This patch therefore adds a new BPF_MAP_TYPE_USER_RINGBUF map type definition. The map type is useless in its current form, as there is no way to access or use it for anything until we one or more BPF helpers. A follow-on patch will therefore add a new helper function that allows BPF programs to run callbacks on samples that are published to the ring buffer. Signed-off-by: David Vernet Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220920000100.477320-2-void@manifault.com

Revert "bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK"

2022-06-14T20:18:06+00:00

This reverts commit a777e18f1bcd32528ff5dfd10a6629b655b05eb8. In commit a777e18f1bcd ("bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK"), we removed the rlimit bump in bpftool, because the kernel has switched to memcg-based memory accounting. Thanks to the LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK, we attempted to keep compatibility with other systems and ask libbpf to raise the limit for us if necessary. How do we know if memcg-based accounting is supported? There is a probe in libbpf to check this. But this probe currently relies on the availability of a given BPF helper, bpf_ktime_get_coarse_ns(), which landed in the same kernel version as the memory accounting change. This works in the generic case, but it may fail, for example, if the helper function has been backported to an older kernel. This has been observed for Google Cloud's Container-Optimized OS (COS), where the helper is available but rlimit is still in use. The probe succeeds, the rlimit is not raised, and probing features with bpftool, for example, fails. A patch was submitted [0] to update this probe in libbpf, based on what the cilium/ebpf Go library does [1]. It would lower the soft rlimit to 0, attempt to load a BPF object, and reset the rlimit. But it may induce some hard-to-debug flakiness if another process starts, or the current application is killed, while the rlimit is reduced, and the approach was discarded. As a workaround to ensure that the rlimit bump does not depend on the availability of a given helper, we restore the unconditional rlimit bump in bpftool for now. [0] https://lore.kernel.org/bpf/20220609143614.97837-1-quentin@isovalent.com/ [1] https://github.com/cilium/ebpf/blob/v0.9.0/rlimit/rlimit.go#L39 Signed-off-by: Quentin Monnet Signed-off-by: Daniel Borkmann Cc: Yafang Shao Cc: Stanislav Fomichev Link: https://lore.kernel.org/bpf/20220610112648.29695-2-quentin@isovalent.com