kernel/git/stable/linux.git/tools/bpf, branch linux-5.19.y

bpftool: Clear errno after libcap's checks

2022-10-24T07:58:10+00:00

[ Upstream commit cea558855c39b7f1f02ff50dcf701ca6596bc964 ] When bpftool is linked against libcap, the library runs a "constructor" function to compute the number of capabilities of the running kernel [0], at the beginning of the execution of the program. As part of this, it performs multiple calls to prctl(). Some of these may fail, and set errno to a non-zero value: # strace -e prctl ./bpftool version prctl(PR_CAPBSET_READ, CAP_MAC_OVERRIDE) = 1 prctl(PR_CAPBSET_READ, 0x30 /* CAP_??? */) = -1 EINVAL (Invalid argument) prctl(PR_CAPBSET_READ, CAP_CHECKPOINT_RESTORE) = 1 prctl(PR_CAPBSET_READ, 0x2c /* CAP_??? */) = -1 EINVAL (Invalid argument) prctl(PR_CAPBSET_READ, 0x2a /* CAP_??? */) = -1 EINVAL (Invalid argument) prctl(PR_CAPBSET_READ, 0x29 /* CAP_??? */) = -1 EINVAL (Invalid argument) ** fprintf added at the top of main(): we have errno == 1 ./bpftool v7.0.0 using libbpf v1.0 features: libbfd, libbpf_strict, skeletons +++ exited with 0 +++ This has been addressed in libcap 2.63 [1], but until this version is available everywhere, we can fix it on bpftool side. Let's clean errno at the beginning of the main() function, to make sure that these checks do not interfere with the batch mode, where we error out if errno is set after a bpftool command. [0] https://git.kernel.org/pub/scm/libs/libcap/libcap.git/tree/libcap/cap_alloc.c?h=libcap-2.65#n20 [1] https://git.kernel.org/pub/scm/libs/libcap/libcap.git/commit/?id=f25a1b7e69f7b33e6afb58b3e38f3450b7d2d9a0 Signed-off-by: Quentin Monnet Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20220815162205.45043-1-quentin@isovalent.com Signed-off-by: Sasha Levin

bpftool: Fix a wrong type cast in btf_dumper_int

2022-10-24T07:57:05+00:00

[ Upstream commit 7184aef9c0f7a81db8fd18d183ee42481d89bf35 ] When `data` points to a boolean value, casting it to `int *` is problematic and could lead to a wrong value being passed to `jsonw_bool`. Change the cast to `bool *` instead. Fixes: b12d6ec09730 ("bpf: btf: add btf print functionality") Signed-off-by: Lam Thai Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20220824225859.9038-1-lamthai@arista.com Signed-off-by: Sasha Levin

bpftool: Use sysfs vmlinux when dumping BTF by ID

2022-05-13T23:07:53+00:00

Currently, dumping almost all BTFs specified by id requires using the -B option to pass the base BTF. For kernel module BTFs the vmlinux BTF sysfs path should work. This patch simplifies dumping by ID usage by loading vmlinux BTF from sysfs as base, if base BTF was not specified and the ID corresponds to a kernel module BTF. Signed-off-by: Larysa Zaremba Signed-off-by: Andrii Nakryiko Reviewed-by: Alexander Lobakin Link: https://lore.kernel.org/bpf/20220513121743.12411-1-larysa.zaremba@intel.com

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: bpf_link_get_from_fd support for LSM programs in lskel

2022-05-10T17:42:08+00:00

bpf_link_get_from_fd currently returns a NULL fd for LSM programs. LSM programs are similar to tracing programs and can also use skel_raw_tracepoint_open. Signed-off-by: KP Singh Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220509214905.3754984-1-kpsingh@kernel.org

bpftool: Declare generator name

2022-05-10T00:42:53+00:00

Most code generators declare its name so did this for bfptool. Signed-off-by: Jason Wang Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220509090247.5457-1-jasowang@redhat.com

bpftool: Output message if no helpers found in feature probing

2022-05-10T00:16:05+00:00

Currently in libbpf, we have hardcoded program types that are not supported for helper function probing (e.g. tracing, ext, lsm). Due to this (and other legitimate failures), bpftool feature probe returns empty for those program type helper functions. Instead of implying to the user that there are no helper functions available for a program type, we output a message to the user explaining that helper function probing failed for that program type. Signed-off-by: Milan Landaverde Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220504161356.3497972-3-milan@mdaverde.com

bpftool: Adjust for error codes from libbpf probes

2022-05-10T00:16:05+00:00

Originally [1], libbpf's (now deprecated) probe functions returned a bool to acknowledge support but the new APIs return an int with a possible negative error code to reflect probe failure. This change decides for bpftool to declare maps and helpers are not available on probe failures. [1]: https://lore.kernel.org/bpf/20220202225916.3313522-3-andrii@kernel.org/ Signed-off-by: Milan Landaverde Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220504161356.3497972-2-milan@mdaverde.com

bpftool, musl compat: Replace sys/fcntl.h by fcntl.h

2022-04-25T21:24:28+00:00

musl does not like including sys/fcntl.h directly: [...] 1 | #warning redirecting incorrect #include to [...] Signed-off-by: Dominique Martinet Signed-off-by: Daniel Borkmann Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20220424051022.2619648-5-asmadeus@codewreck.org

bpftool, musl compat: Replace nftw with FTW_ACTIONRETVAL

2022-04-25T21:24:16+00:00

musl nftw implementation does not support FTW_ACTIONRETVAL. There have been multiple attempts at pushing the feature in musl upstream, but it has been refused or ignored all the times: https://www.openwall.com/lists/musl/2021/03/26/1 https://www.openwall.com/lists/musl/2022/01/22/1 In this case we only care about /proc//fd/, so it's not too difficult to reimplement directly instead, and the new implementation makes 'bpftool perf' slightly faster because it doesn't needlessly stat/readdir unneeded directories (54ms -> 13ms on my machine). Signed-off-by: Dominique Martinet Signed-off-by: Daniel Borkmann Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20220424051022.2619648-4-asmadeus@codewreck.org