linux/scripts/bpf_helpers_doc.py, branch v5.8

bpf: Minor fixes to BPF helpers documentation

2020-05-11T19:20:53Z

Minor improvements to the documentation for BPF helpers: * Fix formatting for the description of "bpf_socket" for bpf_getsockopt() and bpf_setsockopt(), thus suppressing two warnings from rst2man about "Unexpected indentation". * Fix formatting for return values for bpf_sk_assign() and seq_file helpers. * Fix and harmonise formatting, in particular for function/struct names. * Remove blank lines before "Return:" sections. * Replace tabs found in the middle of text lines. * Fix typos. * Add a note to the footer (in Python script) about "bpftool feature probe", including for listing features available to unprivileged users, and add a reference to bpftool man page. Thanks to Florian for reporting two typos (duplicated words). Signed-off-by: Quentin Monnet Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20200511161536.29853-4-quentin@isovalent.com

bpf: Add bpf_seq_printf and bpf_seq_write helpers

2020-05-10T00:05:26Z

Two helpers bpf_seq_printf and bpf_seq_write, are added for writing data to the seq_file buffer. bpf_seq_printf supports common format string flag/width/type fields so at least I can get identical results for netlink and ipv6_route targets. For bpf_seq_printf and bpf_seq_write, return value -EOVERFLOW specifically indicates a write failure due to overflow, which means the object will be repeated in the next bpf invocation if object collection stays the same. Note that if the object collection is changed, depending how collection traversal is done, even if the object still in the collection, it may not be visited. For bpf_seq_printf, format %s, %p{i,I}{4,6} needs to read kernel memory. Reading kernel memory may fail in the following two cases: - invalid kernel address, or - valid kernel address but requiring a major fault If reading kernel memory failed, the %s string will be an empty string and %p{i,I}{4,6} will be all 0. Not returning error to bpf program is consistent with what bpf_trace_printk() does for now. bpf_seq_printf may return -EBUSY meaning that internal percpu buffer for memory copy of strings or other pointees is not available. Bpf program can return 1 to indicate it wants the same object to be repeated. Right now, this should not happen on no-RT kernels since migrate_disable(), which guards bpf prog call, calls preempt_disable(). Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200509175914.2476661-1-yhs@fb.com

bpf_helpers_doc.py: Fix warning when compiling bpftool

2020-03-13T19:53:40Z

When compiling bpftool the following warning is found: "declaration of 'struct bpf_pidns_info' will not be visible outside of this function." This patch adds struct bpf_pidns_info to type_fwds array to fix this. Fixes: b4490c5c4e02 ("bpf: Added new helper bpf_get_ns_current_pid_tgid") Signed-off-by: Carlos Neira Signed-off-by: Daniel Borkmann Reviewed-by: Quentin Monnet Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20200313154650.13366-1-cneirabustos@gmail.com

bpf: Added new helper bpf_get_ns_current_pid_tgid

2020-03-13T00:33:11Z

New bpf helper bpf_get_ns_current_pid_tgid, This helper will return pid and tgid from current task which namespace matches dev_t and inode number provided, this will allows us to instrument a process inside a container. Signed-off-by: Carlos Neira Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200304204157.58695-3-cneirabustos@gmail.com

scripts/bpf: Switch to more portable python3 shebang

2020-02-26T14:42:21Z

Change "/usr/bin/python3" to "/usr/bin/env python3" for more portable solution in bpf_helpers_doc.py. Signed-off-by: Scott Branden Signed-off-by: Daniel Borkmann Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20200225205426.6975-1-scott.branden@broadcom.com

libbpf: Clean up bpf_helper_defs.h generation output

2020-01-14T01:48:13Z

bpf_helpers_doc.py script, used to generate bpf_helper_defs.h, unconditionally emits one informational message to stderr. Remove it and preserve stderr to contain only relevant errors. Also make sure script invocations command is muted by default in libbpf's Makefile. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200113073143.1779940-3-andriin@fb.com

scripts/bpf: Print an error when known types list needs updating

2019-10-21T01:21:21Z

Don't generate a broken bpf_helper_defs.h header if the helper script needs updating because it doesn't recognize a newly added type. Instead print an error that explains why the build is failing, clean up the partially generated header and stop. v1->v2: - Switched from temporary file to .DELETE_ON_ERROR. Fixes: 456a513bb5d4 ("scripts/bpf: Emit an #error directive known types list needs updating") Suggested-by: Andrii Nakryiko Signed-off-by: Jakub Sitnicki Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20191020112344.19395-1-jakub@cloudflare.com

scripts/bpf: Emit an #error directive known types list needs updating

2019-10-16T12:30:03Z

Make the compiler report a clear error when bpf_helpers_doc.py needs updating rather than rely on the fact that Clang fails to compile English: ../../../lib/bpf/bpf_helper_defs.h:2707:1: error: unknown type name 'Unrecognized' Unrecognized type 'struct bpf_inet_lookup', please add it to known types! Signed-off-by: Jakub Sitnicki Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20191016085811.11700-1-jakub@cloudflare.com

scripts/bpf: Fix xdp_md forward declaration typo

2019-10-10T04:43:42Z

Fix typo in struct xpd_md, generated from bpf_helpers_doc.py, which is causing compilation warnings for programs using bpf_helpers.h Fixes: 7a387bed47f7 ("scripts/bpf: teach bpf_helpers_doc.py to dump BPF helper definitions") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191010042534.290562-1-andriin@fb.com

scripts/bpf: teach bpf_helpers_doc.py to dump BPF helper definitions

2019-10-07T05:29:36Z

Enhance scripts/bpf_helpers_doc.py to emit C header with BPF helper definitions (to be included from libbpf's bpf_helpers.h). Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov