kernel/linux.git/tools/bpf/bpftool/map.c, branch v6.1.168

bpftool: Remove asserts from JIT disassembler

2024-12-14T18:54:29+00:00

[ Upstream commit 55b4de58d0e2aca810ed2b198a0173640300acf8 ] 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 Stable-dep-of: ef3ba8c258ee ("bpftool: fix potential NULL pointer dereferencing in prog_dump()") Signed-off-by: Sasha Levin

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

bpftool: Use libbpf_bpf_map_type_str

2022-06-02T23:26:24+00:00

This change switches bpftool over to using the recently introduced libbpf_bpf_map_type_str function instead of maintaining its own string representation for the bpf_map_type enum. Signed-off-by: Daniel Müller Signed-off-by: Andrii Nakryiko Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20220523230428.3077108-7-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

bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK

2022-04-11T03:17:16+00:00

We have switched to memcg-based memory accouting and thus the rlimit is not needed any more. LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK was introduced in libbpf for backward compatibility, so we can use it instead now. libbpf_set_strict_mode always return 0, so we don't need to check whether the return value is 0 or not. Signed-off-by: Yafang Shao Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220409125958.92629-4-laoar.shao@gmail.com

bpftool: Fix print error when show bpf map

2022-03-21T13:58:06+00:00

If there is no btf_id or frozen, it will not show the pids, but the pids don't depend on any one of them. Below is the result after this change: $ ./bpftool map show 2: lpm_trie flags 0x1 key 8B value 8B max_entries 1 memlock 4096B pids systemd(1) 3: lpm_trie flags 0x1 key 20B value 8B max_entries 1 memlock 4096B pids systemd(1) While before this change, the 'pids systemd(1)' can't be displayed. Fixes: 9330986c0300 ("bpf: Add bloom filter map implementation") Signed-off-by: Yafang Shao Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20220320060815.7716-1-laoar.shao@gmail.com

bpftool: Ensure bytes_memlock json output is correct

2022-03-10T23:06:11+00:00

If a BPF map is created over 2^32 the memlock value as displayed in JSON format will be incorrect. Use atoll instead of atoi so that the correct number is displayed. ``` $ bpftool map create /sys/fs/bpf/test_bpfmap type hash key 4 \ value 1024 entries 4194304 name test_bpfmap $ bpftool map list 1: hash name test_bpfmap flags 0x0 key 4B value 1024B max_entries 4194304 memlock 4328521728B $ sudo bpftool map list -j | jq .[].bytes_memlock 33554432 ``` Signed-off-by: Chris J Arges Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/b6601087-0b11-33cc-904a-1133d1500a10@cloudflare.com

bpftool: Fix pretty print dump for maps without BTF loaded

2022-02-16T23:08:55+00:00

The commit e5043894b21f ("bpftool: Use libbpf_get_error() to check error") fails to dump map without BTF loaded in pretty mode (-p option). Fixing this by making sure get_map_kv_btf won't fail in case there's no BTF available for the map. Fixes: e5043894b21f ("bpftool: Use libbpf_get_error() to check error") Suggested-by: Andrii Nakryiko Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220216092102.125448-1-jolsa@kernel.org

bpftool: Fix the error when lookup in no-btf maps

2022-02-15T17:03:40+00:00

When reworking btf__get_from_id() in commit a19f93cfafdf the error handling when calling bpf_btf_get_fd_by_id() changed. Before the rework if bpf_btf_get_fd_by_id() failed the error would not be propagated to callers of btf__get_from_id(), after the rework it is. This lead to a change in behavior in print_key_value() that now prints an error when trying to lookup keys in maps with no btf available. Fix this by following the way used in dumping maps to allow to look up keys in no-btf maps, by which it decides whether and where to get the btf info according to the btf value type. Fixes: a19f93cfafdf ("libbpf: Add internal helper to load BTF data by FD") Signed-off-by: Yinjun Zhang Signed-off-by: Simon Horman Signed-off-by: Andrii Nakryiko Reviewed-by: Niklas Söderlund Acked-by: Jiri Olsa Link: https://lore.kernel.org/bpf/1644249625-22479-1-git-send-email-yinjun.zhang@corigine.com