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2023-02-15Documentation: bpf: Add missing line break separator in node_data struct ↵Bagas Sanjaya
code block Stephen Rothwell reported htmldocs warning when merging bpf-next tree, which was the same warning as reported by kernel test robot: Documentation/bpf/graph_ds_impl.rst:62: ERROR: Error in "code-block" directive: maximum 1 argument(s) allowed, 12 supplied. The error is due to Sphinx confuses node_data struct declaration with code-block directive option. Fix the warning by separating the code-block marker with node_data struct declaration. Link: https://lore.kernel.org/linux-next/20230215144505.4751d823@canb.auug.org.au/ Link: https://lore.kernel.org/linux-doc/202302151123.wUE5FYFx-lkp@intel.com/ Fixes: c31315c3aa0929 ("bpf, documentation: Add graph documentation for non-owning refs") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20230215123253.41552-3-bagasdotme@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-13bpf, documentation: Add graph documentation for non-owning refsDave Marchevsky
It is difficult to intuit the semantics of owning and non-owning references from verifier code. In order to keep the high-level details from being lost in the mailing list, this patch adds documentation explaining semantics and details. The target audience of doc added in this patch is folks working on BPF internals, as there's focus on "what should the verifier do here". Via reorganization or copy-and-paste, much of the content can probably be repurposed for BPF program writer audience as well. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230214004017.2534011-9-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-08bpf, docs: Add note about type conventionDave Thaler
Add explanation about use of "u64", "u32", etc. as the type convention used in BPF documentation. Signed-off-by: Dave Thaler <dthaler@microsoft.com> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230127014706.1005-1-dthaler1968@googlemail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-08bpf/docs: Update design QA to be consistent with kfunc lifecycle docsToke Høiland-Jørgensen
Cong pointed out that there are some inconsistencies between the BPF design QA and the lifecycle expectations documentation we added for kfuncs. Let's update the QA file to be consistent with the kfunc docs, and add references where it makes sense. Also document that modules may export kfuncs now. v3: - Grammar nit + ack from David v2: - Fix repeated word (s/defined defined/defined/) Reported-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: David Vernet <void@manifault.com> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20230208164143.286392-1-toke@redhat.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-07bpf, docs: Use consistent names for the same fieldDave Thaler
Use consistent names for the same field, e.g., 'dst' vs 'dst_reg'. Previously a mix of terms were used for the same thing in various cases. Signed-off-by: Dave Thaler <dthaler@microsoft.com> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230127224555.916-1-dthaler1968@googlemail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-03bpf/docs: Document kfunc lifecycle / stability expectationsDavid Vernet
BPF kernel <-> kernel API stability has been discussed at length over the last several weeks and months. Now that we've largely aligned over kfuncs being the way forward, and BPF helpers being considered functionally frozen, it's time to document the expectations for kfunc lifecycles and stability so that everyone (BPF users, kfunc developers, and maintainers) are all aligned, and have a crystal-clear understanding of the expectations surrounding kfuncs. To do that, this patch adds that documentation to the main kfuncs documentation page via a new 'kfunc lifecycle expectations' section. The patch describes how decisions are made in the kernel regarding whether to include, keep, deprecate, or change / remove a kfunc. As described very overtly in the patch itself, but likely worth highlighting here: "kfunc stability" does not mean, nor ever will mean, "BPF APIs may block development elsewhere in the kernel". Rather, the intention and expectation is for kfuncs to be treated like EXPORT_SYMBOL_GPL symbols in the kernel. The goal is for kfuncs to be a safe and valuable option for maintainers and kfunc developers to extend the kernel, without tying anyone's hands, or imposing any kind of restrictions on maintainers in the same way that UAPI changes do. In addition to the 'kfunc lifecycle expectations' section, this patch also adds documentation for a new KF_DEPRECATED kfunc flag which kfunc authors or maintainers can choose to add to kfuncs if and when they decide to deprecate them. Note that as described in the patch itself, a kfunc need not be deprecated before being changed or removed -- this flag is simply provided as an available deprecation mechanism for those that want to provide a deprecation story / timeline to their users. When necessary, kfuncs may be changed or removed to accommodate changes elsewhere in the kernel without any deprecation at all. Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Co-developed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230203155727.793518-2-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-02docs/bpf: Add description of register liveness tracking algorithmEduard Zingerman
This is a followup for [1], adds an overview for the register liveness tracking, covers the following points: - why register liveness tracking is useful; - how register parentage chains are constructed; - how liveness marks are applied using the parentage chains. [1] https://lore.kernel.org/bpf/CAADnVQKs2i1iuZ5SUGuJtxWVfGYR9kDgYKhq3rNV+kBLQCu7rA@mail.gmail.com/ Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Reviewed-by: Edward Cree <ecree.xilinx@gmail.com> Link: https://lore.kernel.org/r/20230202125713.821931-2-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-02bpf: Document usage of the new __bpf_kfunc macroDavid Vernet
Now that the __bpf_kfunc macro has been added to linux/btf.h, include a blurb about it in the kfuncs.rst file. In order for the macro to successfully render with .. kernel-doc, we'll also need to add it to the c_id_attributes array. Signed-off-by: David Vernet <void@manifault.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20230201173016.342758-3-void@manifault.com
2023-01-28Documentation: bpf: correct spellingRandy Dunlap
Correct spelling problems for Documentation/bpf/ as reported by codespell. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: bpf@vger.kernel.org Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20230128195046.13327-1-rdunlap@infradead.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-25bpf/docs: Document the nocast aliasing behavior of ___initDavid Vernet
When comparing BTF IDs for pointers being passed to kfunc arguments, the verifier will allow pointer types that are equivalent according to the C standard. For example, for: struct bpf_cpumask { cpumask_t cpumask; refcount_t usage; }; The verifier will allow a struct bpf_cpumask * to be passed to a kfunc that takes a const struct cpumask * (cpumask_t is a typedef of struct cpumask). The exception to this rule is if a type is suffixed with ___init, such as: struct nf_conn___init { struct nf_conn ct; }; The verifier will _not_ allow a struct nf_conn___init * to be passed to a kfunc that expects a struct nf_conn *. This patch documents this behavior in the kfuncs documentation page. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230125143816.721952-8-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-25bpf/docs: Document how nested trusted fields may be definedDavid Vernet
A prior change defined a new BTF_TYPE_SAFE_NESTED macro in the verifier which allows developers to specify when a pointee field in a struct type should inherit its parent pointer's trusted status. This patch updates the kfuncs documentation to specify this macro and how it can be used. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230125143816.721952-7-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-25bpf/docs: Document cpumask kfuncs in a new fileDavid Vernet
Now that we've added a series of new cpumask kfuncs, we should document them so users can easily use them. This patch adds a new cpumasks.rst file to document them. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230125143816.721952-6-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-24bpf, docs: Fix modulo zero, division by zero, overflow, and underflowDave Thaler
Fix modulo zero, division by zero, overflow, and underflow. Also clarify how a negative immediate value is used in unsigned division. Signed-off-by: Dave Thaler <dthaler@microsoft.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230124001218.827-1-dthaler1968@googlemail.com
2023-01-04Merge tag 'for-netdev' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== bpf-next 2023-01-04 We've added 45 non-merge commits during the last 21 day(s) which contain a total of 50 files changed, 1454 insertions(+), 375 deletions(-). The main changes are: 1) Fixes, improvements and refactoring of parts of BPF verifier's state equivalence checks, from Andrii Nakryiko. 2) Fix a few corner cases in libbpf's BTF-to-C converter in particular around padding handling and enums, also from Andrii Nakryiko. 3) Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata, from Christian Ehrig. 4) Improve x86 JIT's codegen for PROBE_MEM runtime error checks, from Dave Marchevsky. 5) Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers, from Jiri Olsa. 6) Add proper documentation for BPF_MAP_TYPE_SOCK{MAP,HASH} maps, from Maryam Tahhan. 7) Improvements in libbpf's btf_parse_elf error handling, from Changbin Du. 8) Bigger batch of improvements to BPF tracing code samples, from Daniel T. Lee. 9) Add LoongArch support to libbpf's bpf_tracing helper header, from Hengqi Chen. 10) Fix a libbpf compiler warning in perf_event_open_probe on arm32, from Khem Raj. 11) Optimize bpf_local_storage_elem by removing 56 bytes of padding, from Martin KaFai Lau. 12) Use pkg-config to locate libelf for resolve_btfids build, from Shen Jiamin. 13) Various libbpf improvements around API documentation and errno handling, from Xin Liu. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (45 commits) libbpf: Return -ENODATA for missing btf section libbpf: Add LoongArch support to bpf_tracing.h libbpf: Restore errno after pr_warn. libbpf: Added the description of some API functions libbpf: Fix invalid return address register in s390 samples/bpf: Use BPF_KSYSCALL macro in syscall tracing programs samples/bpf: Fix tracex2 by using BPF_KSYSCALL macro samples/bpf: Change _kern suffix to .bpf with syscall tracing program samples/bpf: Use vmlinux.h instead of implicit headers in syscall tracing program samples/bpf: Use kyscall instead of kprobe in syscall tracing program bpf: rename list_head -> graph_root in field info types libbpf: fix errno is overwritten after being closed. bpf: fix regs_exact() logic in regsafe() to remap IDs correctly bpf: perform byte-by-byte comparison only when necessary in regsafe() bpf: reject non-exact register type matches in regsafe() bpf: generalize MAYBE_NULL vs non-MAYBE_NULL rule bpf: reorganize struct bpf_reg_state fields bpf: teach refsafe() to take into account ID remapping bpf: Remove unused field initialization in bpf's ctl_table selftests/bpf: Add jit probe_mem corner case tests to s390x denylist ... ==================== Link: https://lore.kernel.org/r/20230105000926.31350-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-20docs: BPF_MAP_TYPE_SOCK[MAP|HASH]Maryam Tahhan
Add documentation for BPF_MAP_TYPE_SOCK[MAP|HASH] including kernel versions introduced, usage and examples. Signed-off-by: Maryam Tahhan <mtahhan@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20221219095512.26534-1-mtahhan@redhat.com
2022-12-14docs/bpf: Reword docs for BPF_MAP_TYPE_SK_STORAGEDonald Hunter
Improve the grammar of the function descriptions and highlight that the key is a socket fd. Fixes: f3212ad5b7e9 ("docs/bpf: Add documentation for BPF_MAP_TYPE_SK_STORAGE") Reported-by: Martin KaFai Lau <martin.lau@linux.dev> Signed-off-by: Donald Hunter <donald.hunter@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20221212101600.56026-1-donald.hunter@gmail.com
2022-12-09docs/bpf: Add documentation for BPF_MAP_TYPE_SK_STORAGEDonald Hunter
Add documentation for the BPF_MAP_TYPE_SK_STORAGE including kernel version introduced, usage and examples. Signed-off-by: Donald Hunter <donald.hunter@gmail.com> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20221209112401.69319-1-donald.hunter@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-12-07bpf/docs: Document struct cgroup * kfuncsDavid Vernet
bpf_cgroup_acquire(), bpf_cgroup_release(), bpf_cgroup_kptr_get(), and bpf_cgroup_ancestor(), are kfuncs that were recently added to kernel/bpf/helpers.c. These are "core" kfuncs in that they're available for use in any tracepoint or struct_ops BPF program. Though they have no ABI stability guarantees, we should still document them. This patch adds a struct cgroup * subsection to the Core kfuncs section which describes each of these kfuncs. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20221207204911.873646-3-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-12-07bpf/docs: Document struct task_struct * kfuncsDavid Vernet
bpf_task_acquire(), bpf_task_release(), and bpf_task_from_pid() are kfuncs that were recently added to kernel/bpf/helpers.c. These are "core" kfuncs in that they're available for use for any tracepoint or struct_ops BPF program. Though they have no ABI stability guarantees, we should still document them. This patch adds a new Core kfuncs section to the BPF kfuncs doc, and adds entries for all of these task kfuncs. Note that bpf_task_kptr_get() is not documented, as it still returns NULL while we're working to resolve how it can use RCU to ensure struct task_struct * lifetime. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20221207204911.873646-2-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-12-04bpf, docs: BPF Iterator DocumentSreevani Sreejith
Document that describes how BPF iterators work, how to use iterators, and how to pass parameters in BPF iterators. Acked-by: David Vernet <void@manifault.com> Signed-off-by: Sreevani Sreejith <psreep@gmail.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20221202221710.320810-2-ssreevani@meta.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-12-04docs/bpf: Add KF_RCU documentationYonghong Song
Add proper KF_RCU documentation in kfuncs.rst. Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20221203184613.478967-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-12-02bpf, docs: Correct the example of BPF_XORZheng Yejian
Refer to description of BPF_XOR, dst_reg should be used but not src_reg in the examples. Fixes: be3193cded9d ("bpf, docs: Add subsections for ALU and JMP instructions") Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221129134558.2757043-1-zhengyejian1@huawei.com
2022-11-25docs/bpf: Add BPF_MAP_TYPE_XSKMAP documentationMaryam Tahhan
Add documentation for BPF_MAP_TYPE_XSKMAP including kernel version introduced, usage and examples. Signed-off-by: Maryam Tahhan <mtahhan@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221123090043.83945-1-mtahhan@redhat.com
2022-11-25docs/bpf: Update btf selftests program and add linkRong Tao
Commit c64779e24e88("selftests/bpf: Merge most of test_btf into test_progs") renamed the BTF selftest from 'test_btf.c' to 'prog_tests/btf.c'. Signed-off-by: Rong Tao <rongtao@cestc.cn> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/tencent_1FA6904156E8E599CAE4ABDBE80F22830106@qq.com
2022-11-24docs/bpf: Fix sphinx warnings in BPF map docsDonald Hunter
Fix duplicate C declaration warnings when using sphinx >= 3.1. Reported-by: Akira Yokosawa <akiyks@gmail.com> Signed-off-by: Donald Hunter <donald.hunter@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Akira Yokosawa <akiyks@gmail.com> Link: https://lore.kernel.org/bpf/ed4dac84-1b12-5c58-e4de-93ab9ac67c09@gmail.com Link: https://lore.kernel.org/bpf/20221122143933.91321-1-donald.hunter@gmail.com
2022-11-23docs/bpf: Document BPF_MAP_TYPE_BLOOM_FILTERDonald Hunter
Add documentation for BPF_MAP_TYPE_BLOOM_FILTER including kernel BPF helper usage, userspace usage and examples. Signed-off-by: Donald Hunter <donald.hunter@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/bpf/20221123141151.54556-1-donald.hunter@gmail.com
2022-11-23docs/bpf: Fix sphinx warnings for devmapMaryam Tahhan
Sphinx version >=3.1 warns about duplicate function declarations in the DEVMAP documentation. This is because the function name is the same for kernel and user space BPF progs but the parameters and return types they take is what differs. This patch moves from using the ``c:function::`` directive to using the ``code-block:: c`` directive. The patches also fix the indentation for the text associated with the "new" code block delcarations. The missing support of c:namespace-push:: and c:namespace-pop:: directives by helper scripts for kernel documentation prevents using the ``c:function::`` directive with proper namespacing. Signed-off-by: Maryam Tahhan <mtahhan@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221123092321.88558-3-mtahhan@redhat.com
2022-11-23docs/bpf: Fix sphinx warnings for cpumapMaryam Tahhan
Sphinx version >=3.1 warns about duplicate function declarations in the CPUMAP documentation. This is because the function name is the same for kernel and user space BPF progs but the parameters and return types they take is what differs. This patch moves from using the ``c:function::`` directive to using the ``code-block:: c`` directive. The patches also fix the indentation for the text associated with the "new" code block delcarations. The missing support of c:namespace-push:: and c:namespace-pop:: directives by helper scripts for kernel documentation prevents using the ``c:function::`` directive with proper namespacing. Signed-off-by: Maryam Tahhan <mtahhan@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221123092321.88558-2-mtahhan@redhat.com
2022-11-23docs/bpf: Add table of BPF program types to libbpf docsDonald Hunter
Extend the libbpf documentation with a table of program types, attach points and ELF section names. Signed-off-by: Donald Hunter <donald.hunter@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20221121121734.98329-1-donald.hunter@gmail.com
2022-11-20bpf: Allow trusted pointers to be passed to KF_TRUSTED_ARGS kfuncsDavid Vernet
Kfuncs currently support specifying the KF_TRUSTED_ARGS flag to signal to the verifier that it should enforce that a BPF program passes it a "safe", trusted pointer. Currently, "safe" means that the pointer is either PTR_TO_CTX, or is refcounted. There may be cases, however, where the kernel passes a BPF program a safe / trusted pointer to an object that the BPF program wishes to use as a kptr, but because the object does not yet have a ref_obj_id from the perspective of the verifier, the program would be unable to pass it to a KF_ACQUIRE | KF_TRUSTED_ARGS kfunc. The solution is to expand the set of pointers that are considered trusted according to KF_TRUSTED_ARGS, so that programs can invoke kfuncs with these pointers without getting rejected by the verifier. There is already a PTR_UNTRUSTED flag that is set in some scenarios, such as when a BPF program reads a kptr directly from a map without performing a bpf_kptr_xchg() call. These pointers of course can and should be rejected by the verifier. Unfortunately, however, PTR_UNTRUSTED does not cover all the cases for safety that need to be addressed to adequately protect kfuncs. Specifically, pointers obtained by a BPF program "walking" a struct are _not_ considered PTR_UNTRUSTED according to BPF. For example, say that we were to add a kfunc called bpf_task_acquire(), with KF_ACQUIRE | KF_TRUSTED_ARGS, to acquire a struct task_struct *. If we only used PTR_UNTRUSTED to signal that a task was unsafe to pass to a kfunc, the verifier would mistakenly allow the following unsafe BPF program to be loaded: SEC("tp_btf/task_newtask") int BPF_PROG(unsafe_acquire_task, struct task_struct *task, u64 clone_flags) { struct task_struct *acquired, *nested; nested = task->last_wakee; /* Would not be rejected by the verifier. */ acquired = bpf_task_acquire(nested); if (!acquired) return 0; bpf_task_release(acquired); return 0; } To address this, this patch defines a new type flag called PTR_TRUSTED which tracks whether a PTR_TO_BTF_ID pointer is safe to pass to a KF_TRUSTED_ARGS kfunc or a BPF helper function. PTR_TRUSTED pointers are passed directly from the kernel as a tracepoint or struct_ops callback argument. Any nested pointer that is obtained from walking a PTR_TRUSTED pointer is no longer PTR_TRUSTED. From the example above, the struct task_struct *task argument is PTR_TRUSTED, but the 'nested' pointer obtained from 'task->last_wakee' is not PTR_TRUSTED. A subsequent patch will add kfuncs for storing a task kfunc as a kptr, and then another patch will add selftests to validate. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20221120051004.3605026-3-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-18bpf, docs: DEVMAPs and XDP_REDIRECTMaryam Tahhan
Add documentation for BPF_MAP_TYPE_DEVMAP and BPF_MAP_TYPE_DEVMAP_HASH including kernel version introduced, usage and examples. Add documentation that describes XDP_REDIRECT. Signed-off-by: Maryam Tahhan <mtahhan@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20221115144921.165483-1-mtahhan@redhat.com
2022-11-17bpf: Support constant scalar arguments for kfuncsKumar Kartikeya Dwivedi
Allow passing known constant scalars as arguments to kfuncs that do not represent a size parameter. We use mark_chain_precision for the constant scalar argument to mark it precise. This makes the search pruning optimization of verifier more conservative for such kfunc calls, and each non-distinct argument is considered unequivalent. We will use this support to then expose a bpf_obj_new function where it takes the local type ID of a type in program BTF, and returns a PTR_TO_BTF_ID | MEM_ALLOC to the local type, and allows programs to allocate their own objects. Each type ID resolves to a distinct type with a possibly distinct size, hence the type ID constant matters in terms of program safety and its precision needs to be checked between old and cur states inside regsafe. The use of mark_chain_precision enables this. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221118015614.2013203-13-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-17bpf/docs: Include blank lines between bullet points in bpf_devel_QA.rstDaniel Müller
Commit 26a9b433cf08 ("bpf/docs: Document how to run CI without patch submission") caused a warning to be generated when compiling the documentation: > bpf_devel_QA.rst:55: WARNING: Unexpected indentation. > bpf_devel_QA.rst:56: WARNING: Block quote ends without a blank line This change fixes the problem by inserting the required blank lines. Fixes: 26a9b433cf08 ("bpf/docs: Document how to run CI without patch submission") Reported-by: Akira Yokosawa <akiyks@gmail.com> Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Akira Yokosawa <akiyks@gmail.com> Link: https://lore.kernel.org/bpf/20221116174358.2744613-1-deso@posteo.net
2022-11-15docs/bpf: Fix sample code in MAP_TYPE_ARRAY docsDonald Hunter
Remove mistaken & from code example in MAP_TYPE_ARRAY docs Fixes: 1cfa97b30c5a ("bpf, docs: Document BPF_MAP_TYPE_ARRAY") Signed-off-by: Donald Hunter <donald.hunter@gmail.com> Link: https://lore.kernel.org/r/20221115095910.86407-1-donald.hunter@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-15bpf/docs: Document how to run CI without patch submissionDaniel Müller
This change documents the process for running the BPF CI before submitting a patch to the upstream mailing list, similar to what happens if a patch is send to bpf@vger.kernel.org: it builds kernel and selftests and runs the latter on different architecture (but it notably does not cover stylistic checks such as cover letter verification). Running BPF CI this way can help achieve better test coverage ahead of patch submission than merely running locally (say, using tools/testing/selftests/bpf/vmtest.sh), as additional architectures may be covered as well. Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20221114211501.2068684-1-deso@posteo.net
2022-11-14bpf: Remove local kptr references in documentationKumar Kartikeya Dwivedi
We don't want to commit to a specific name for these. Simply call them allocated objects coming from bpf_obj_new, which is completely clear in itself. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221114191547.1694267-2-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-14bpf, docs: Fixup cpumap sphinx >= 3.1 warningMaryam Tahhan
Fixup bpf_map_update_elem() declaration to use a single line. Reported-by: Akira Yokosawa <akiyks@gmail.com> Signed-off-by: Maryam Tahhan <mtahhan@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Akira Yokosawa <akiyks@gmail.com> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20221113103327.3287482-1-mtahhan@redhat.com
2022-11-11bpf, docs: Document BPF_MAP_TYPE_ARRAYDave Tucker
Add documentation for the BPF_MAP_TYPE_ARRAY including kernel version introduced, usage and examples. Also document BPF_MAP_TYPE_PERCPU_ARRAY which is similar. Co-developed-by: Donald Hunter <donald.hunter@gmail.com> Signed-off-by: Dave Tucker <dave@dtucker.co.uk> Signed-off-by: Donald Hunter <donald.hunter@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Maryam Tahhan <mtahhan@redhat.com> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/bpf/20221109174604.31673-2-donald.hunter@gmail.com
2022-11-11docs/bpf: Document BPF map types QUEUE and STACKDonald Hunter
Add documentation for BPF_MAP_TYPE_QUEUE and BPF_MAP_TYPE_STACK, including usage and examples. Signed-off-by: Donald Hunter <donald.hunter@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20221108093314.44851-1-donald.hunter@gmail.com
2022-11-11docs/bpf: Document BPF ARRAY_OF_MAPS and HASH_OF_MAPSDonald Hunter
Add documentation for the ARRAY_OF_MAPS and HASH_OF_MAPS map types, including usage and examples. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Donald Hunter <donald.hunter@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20221108102215.47297-1-donald.hunter@gmail.com
2022-11-11docs/bpf: Document BPF_MAP_TYPE_CPUMAP mapMaryam Tahhan
Add documentation for BPF_MAP_TYPE_CPUMAP including kernel version introduced, usage and examples. Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Maryam Tahhan <mtahhan@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20221107165207.2682075-2-mtahhan@redhat.com
2022-11-11docs/bpf: Document BPF_MAP_TYPE_LPM_TRIE mapDonald Hunter
Add documentation for BPF_MAP_TYPE_LPM_TRIE including kernel BPF helper usage, userspace usage and examples. Signed-off-by: Donald Hunter <donald.hunter@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221101114542.24481-2-donald.hunter@gmail.com
2022-11-04Documentation: bpf: Escape underscore in BPF type name prefixBagas Sanjaya
Sphinx reported unknown target warning: Documentation/bpf/bpf_design_QA.rst:329: WARNING: Unknown target name: "bpf". The warning is caused by BPF type name prefix ("bpf_") which is written without escaping the trailing underscore. Escape the underscore to fix the warning. While at it, wrap the containing paragraph in less than 80 characters. Fixes: 9805af8d8a5b17 ("bpf: Document UAPI details for special BPF types") Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: KP Singh <kpsingh@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20221104123913.50610-1-bagasdotme@gmail.com
2022-11-03bpf: Document UAPI details for special BPF typesKumar Kartikeya Dwivedi
The kernel recognizes some special BPF types in map values or local kptrs. Document that only bpf_spin_lock and bpf_timer will preserve backwards compatibility, and kptr will preserve backwards compatibility for the operations on the pointer, not the types supported for such kptrs. For local kptrs, document that there are no stability guarantees at all. Finally, document that 'bpf_' namespace is reserved for adding future special fields, hence BPF programs must not declare types with such names in their programs and still expect backwards compatibility. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20221103191013.1236066-2-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-10-25docs/bpf: Add documentation for new cgroup local storageYonghong Song
Add some descriptions and examples for BPF_MAP_TYPE_CGRP_STORAGE. Also illustate the major difference between BPF_MAP_TYPE_CGRP_STORAGE and BPF_MAP_TYPE_CGROUP_STORAGE and recommend to use BPF_MAP_TYPE_CGRP_STORAGE instead of BPF_MAP_TYPE_CGROUP_STORAGE in the end. Acked-by: David Vernet <void@manifault.com> Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20221026042922.676383-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-10-20bpf, docs: Reformat BPF maps page to be more readableDonald Hunter
Add a more complete introduction, with links to man pages. Move toctree of map types above usage notes. Format usage notes to improve readability. Signed-off-by: Donald Hunter <donald.hunter@gmail.com> Link: https://lore.kernel.org/r/20221012152715.25073-1-donald.hunter@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-10-04Merge tag 'net-next-6.1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - Introduce and use a single page frag cache for allocating small skb heads, clawing back the 10-20% performance regression in UDP flood test from previous fixes. - Run packets which already went thru HW coalescing thru SW GRO. This significantly improves TCP segment coalescing and simplifies deployments as different workloads benefit from HW or SW GRO. - Shrink the size of the base zero-copy send structure. - Move TCP init under a new slow / sleepable version of DO_ONCE(). BPF: - Add BPF-specific, any-context-safe memory allocator. - Add helpers/kfuncs for PKCS#7 signature verification from BPF programs. - Define a new map type and related helpers for user space -> kernel communication over a ring buffer (BPF_MAP_TYPE_USER_RINGBUF). - Allow targeting BPF iterators to loop through resources of one task/thread. - Add ability to call selected destructive functions. Expose crash_kexec() to allow BPF to trigger a kernel dump. Use CAP_SYS_BOOT check on the loading process to judge permissions. - Enable BPF to collect custom hierarchical cgroup stats efficiently by integrating with the rstat framework. - Support struct arguments for trampoline based programs. Only structs with size <= 16B and x86 are supported. - Invoke cgroup/connect{4,6} programs for unprivileged ICMP ping sockets (instead of just TCP and UDP sockets). - Add a helper for accessing CLOCK_TAI for time sensitive network related programs. - Support accessing network tunnel metadata's flags. - Make TCP SYN ACK RTO tunable by BPF programs with TCP Fast Open. - Add support for writing to Netfilter's nf_conn:mark. Protocols: - WiFi: more Extremely High Throughput (EHT) and Multi-Link Operation (MLO) work (802.11be, WiFi 7). - vsock: improve support for SO_RCVLOWAT. - SMC: support SO_REUSEPORT. - Netlink: define and document how to use netlink in a "modern" way. Support reporting missing attributes via extended ACK. - IPSec: support collect metadata mode for xfrm interfaces. - TCPv6: send consistent autoflowlabel in SYN_RECV state and RST packets. - TCP: introduce optional per-netns connection hash table to allow better isolation between namespaces (opt-in, at the cost of memory and cache pressure). - MPTCP: support TCP_FASTOPEN_CONNECT. - Add NEXT-C-SID support in Segment Routing (SRv6) End behavior. - Adjust IP_UNICAST_IF sockopt behavior for connected UDP sockets. - Open vSwitch: - Allow specifying ifindex of new interfaces. - Allow conntrack and metering in non-initial user namespace. - TLS: support the Korean ARIA-GCM crypto algorithm. - Remove DECnet support. Driver API: - Allow selecting the conduit interface used by each port in DSA switches, at runtime. - Ethernet Power Sourcing Equipment and Power Device support. - Add tc-taprio support for queueMaxSDU parameter, i.e. setting per traffic class max frame size for time-based packet schedules. - Support PHY rate matching - adapting between differing host-side and link-side speeds. - Introduce QUSGMII PHY mode and 1000BASE-KX interface mode. - Validate OF (device tree) nodes for DSA shared ports; make phylink-related properties mandatory on DSA and CPU ports. Enforcing more uniformity should allow transitioning to phylink. - Require that flash component name used during update matches one of the components for which version is reported by info_get(). - Remove "weight" argument from driver-facing NAPI API as much as possible. It's one of those magic knobs which seemed like a good idea at the time but is too indirect to use in practice. - Support offload of TLS connections with 256 bit keys. New hardware / drivers: - Ethernet: - Microchip KSZ9896 6-port Gigabit Ethernet Switch - Renesas Ethernet AVB (EtherAVB-IF) Gen4 SoCs - Analog Devices ADIN1110 and ADIN2111 industrial single pair Ethernet (10BASE-T1L) MAC+PHY. - Rockchip RV1126 Gigabit Ethernet (a version of stmmac IP). - Ethernet SFPs / modules: - RollBall / Hilink / Turris 10G copper SFPs - HALNy GPON module - WiFi: - CYW43439 SDIO chipset (brcmfmac) - CYW89459 PCIe chipset (brcmfmac) - BCM4378 on Apple platforms (brcmfmac) Drivers: - CAN: - gs_usb: HW timestamp support - Ethernet PHYs: - lan8814: cable diagnostics - Ethernet NICs: - Intel (100G): - implement control of FCS/CRC stripping - port splitting via devlink - L2TPv3 filtering offload - nVidia/Mellanox: - tunnel offload for sub-functions - MACSec offload, w/ Extended packet number and replay window offload - significantly restructure, and optimize the AF_XDP support, align the behavior with other vendors - Huawei: - configuring DSCP map for traffic class selection - querying standard FEC statistics - querying SerDes lane number via ethtool - Marvell/Cavium: - egress priority flow control - MACSec offload - AMD/SolarFlare: - PTP over IPv6 and raw Ethernet - small / embedded: - ax88772: convert to phylink (to support SFP cages) - altera: tse: convert to phylink - ftgmac100: support fixed link - enetc: standard Ethtool counters - macb: ZynqMP SGMII dynamic configuration support - tsnep: support multi-queue and use page pool - lan743x: Rx IP & TCP checksum offload - igc: add xdp frags support to ndo_xdp_xmit - Ethernet high-speed switches: - Marvell (prestera): - support SPAN port features (traffic mirroring) - nexthop object offloading - Microchip (sparx5): - multicast forwarding offload - QoS queuing offload (tc-mqprio, tc-tbf, tc-ets) - Ethernet embedded switches: - Marvell (mv88e6xxx): - support RGMII cmode - NXP (felix): - standardized ethtool counters - Microchip (lan966x): - QoS queuing offload (tc-mqprio, tc-tbf, tc-cbs, tc-ets) - traffic policing and mirroring - link aggregation / bonding offload - QUSGMII PHY mode support - Qualcomm 802.11ax WiFi (ath11k): - cold boot calibration support on WCN6750 - support to connect to a non-transmit MBSSID AP profile - enable remain-on-channel support on WCN6750 - Wake-on-WLAN support for WCN6750 - support to provide transmit power from firmware via nl80211 - support to get power save duration for each client - spectral scan support for 160 MHz - MediaTek WiFi (mt76): - WiFi-to-Ethernet bridging offload for MT7986 chips - RealTek WiFi (rtw89): - P2P support" * tag 'net-next-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1864 commits) eth: pse: add missing static inlines once: rename _SLOW to _SLEEPABLE net: pse-pd: add regulator based PSE driver dt-bindings: net: pse-dt: add bindings for regulator based PoDL PSE controller ethtool: add interface to interact with Ethernet Power Equipment net: mdiobus: search for PSE nodes by parsing PHY nodes. net: mdiobus: fwnode_mdiobus_register_phy() rework error handling net: add framework to support Ethernet PSE and PDs devices dt-bindings: net: phy: add PoDL PSE property net: marvell: prestera: Propagate nh state from hw to kernel net: marvell: prestera: Add neighbour cache accounting net: marvell: prestera: add stub handler neighbour events net: marvell: prestera: Add heplers to interact with fib_notifier_info net: marvell: prestera: Add length macros for prestera_ip_addr net: marvell: prestera: add delayed wq and flush wq on deinit net: marvell: prestera: Add strict cleanup of fib arbiter net: marvell: prestera: Add cleanup of allocated fib_nodes net: marvell: prestera: Add router nexthops ABI eth: octeon: fix build after netif_napi_add() changes net/mlx5: E-Switch, Return EBUSY if can't get mode lock ...
2022-10-03Documentation: bpf: Add implementation notes documentations to table of contentsBagas Sanjaya
Sphinx reported warnings on missing implementation notes documentations in the table of contents: Documentation/bpf/clang-notes.rst: WARNING: document isn't included in any toctree Documentation/bpf/linux-notes.rst: WARNING: document isn't included in any toctree Add these documentations to the table of contents (index.rst) of BPF documentation to fix the warnings. Link: https://lore.kernel.org/linux-doc/202210020749.yfgDZbRL-lkp@intel.com/ Fixes: 6c7aaffb24efbd ("bpf, docs: Move Clang notes to a separate file") Fixes: 6166da0a02cde2 ("bpf, docs: Move legacy packet instructions to a separate file") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20221002032022.24693-1-bagasdotme@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-10-01bpf, docs: Delete misformatted table.Alexei Starovoitov
Delete misformatted table. Fixes: 6166da0a02cd ("bpf, docs: Move legacy packet instructions to a separate file") Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-30bpf, docs: Add TOC and fix formatting.Dave Thaler
Add TOC and fix formatting. Signed-off-by: Dave Thaler <dthaler@microsoft.com> Link: https://lore.kernel.org/r/20220927185958.14995-5-dthaler1968@googlemail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
generated by cgit (git 2.34.1) at 2024-07-06 19:34:33 +0000