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2024-01-12Merge tag 'docs-6.8' of git://git.lwn.net/linuxLinus Torvalds1-4/+2
Pull documentation update from Jonathan Corbet: "Another moderately busy cycle for documentation, including: - The minimum Sphinx requirement has been raised to 2.4.4, following a warning that was added in 6.2 - Some reworking of the Documentation/process front page to, hopefully, make it more useful - Various kernel-doc tweaks to, for example, make it deal properly with __counted_by annotations - We have also restored a warning for documentation of nonexistent structure members that disappeared a while back. That had the delightful consequence of adding some 600 warnings to the docs build. A sustained effort by Randy, Vegard, and myself has addressed almost all of those, bringing the documentation back into sync with the code. The fixes are going through the appropriate maintainer trees - Various improvements to the HTML rendered docs, including automatic links to Git revisions and a nice new pulldown to make translations easy to access - Speaking of translations, more of those for Spanish and Chinese ... plus the usual stream of documentation updates and typo fixes" * tag 'docs-6.8' of git://git.lwn.net/linux: (57 commits) MAINTAINERS: use tabs for indent of CONFIDENTIAL COMPUTING THREAT MODEL A reworked process/index.rst ring-buffer/Documentation: Add documentation on buffer_percent file Translated the RISC-V architecture boot documentation. Docs: remove mentions of fdformat from util-linux Docs/zh_CN: Fix the meaning of DEBUG to pr_debug() Documentation: move driver-api/dcdbas to userspace-api/ Documentation: move driver-api/isapnp to userspace-api/ Documentation/core-api : fix typo in workqueue Documentation/trace: Fixed typos in the ftrace FLAGS section kernel-doc: handle a void function without producing a warning scripts/get_abi.pl: ignore some temp files docs: kernel_abi.py: fix command injection scripts/get_abi: fix source path leak CREDITS, MAINTAINERS, docs/process/howto: Update man-pages' maintainer docs: translations: add translations links when they exist kernel-doc: Align quick help and the code MAINTAINERS: add reviewer for Spanish translations docs: ignore __counted_by attribute in structure definitions scripts: kernel-doc: Clarify missing struct member description ..
2023-12-10bpf: Add bpf_cpumask_weight() kfuncDavid Vernet1-1/+1
It can be useful to query how many bits are set in a cpumask. For example, if you want to perform special logic for the last remaining core that's set in a mask. Let's therefore add a new bpf_cpumask_weight() kfunc which checks how many bits are set in a mask. Signed-off-by: David Vernet <void@manifault.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20231207210843.168466-2-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-02Documentation/bpf: Add documentation for filesystem kfuncsSong Liu2-0/+22
Add a brief introduction for file system kfuncs: bpf_get_file_xattr() bpf_get_fsverity_digest() The documentation highlights the strategy to avoid recursions of these kfuncs. Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231129234417.856536-4-song@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-11-17docs: automarkup: linkify git revsVegard Nossum1-4/+2
There aren't a ton of references to commits in the documentation, but they do exist, and we can use automarkup to linkify them to make them easier to follow. Use something like this to find references to commits: git grep -P 'commit.*[0-9a-f]{8,}' Documentation/ Also fix a few of these to standardize on the exact format that is already used in changelogs. Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20231027115420.205279-1-vegard.nossum@oracle.com
2023-11-10bpf: Introduce KF_ARG_PTR_TO_CONST_STRSong Liu1-0/+24
Similar to ARG_PTR_TO_CONST_STR for BPF helpers, KF_ARG_PTR_TO_CONST_STR specifies kfunc args that point to const strings. Annotation "__str" is used to specify kfunc arg of type KF_ARG_PTR_TO_CONST_STR. Also, add documentation for the "__str" annotation. bpf_get_file_xattr() will be the first kfunc that uses this type. Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Link: https://lore.kernel.org/bpf/20231107045725.2278852-4-song@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-11-02bpf: Add __bpf_kfunc_{start,end}_defs macrosDave Marchevsky1-4/+2
BPF kfuncs are meant to be called from BPF programs. Accordingly, most kfuncs are not called from anywhere in the kernel, which the -Wmissing-prototypes warning is unhappy about. We've peppered __diag_ignore_all("-Wmissing-prototypes", ... everywhere kfuncs are defined in the codebase to suppress this warning. This patch adds two macros meant to bound one or many kfunc definitions. All existing kfunc definitions which use these __diag calls to suppress -Wmissing-prototypes are migrated to use the newly-introduced macros. A new __diag_ignore_all - for "-Wmissing-declarations" - is added to the __bpf_kfunc_start_defs macro based on feedback from Andrii on an earlier version of this patch [0] and another recent mailing list thread [1]. In the future we might need to ignore different warnings or do other kfunc-specific things. This change will make it easier to make such modifications for all kfunc defs. [0]: https://lore.kernel.org/bpf/CAEf4BzaE5dRWtK6RPLnjTW-MW9sx9K3Fn6uwqCTChK2Dcb1Xig@mail.gmail.com/ [1]: https://lore.kernel.org/bpf/ZT+2qCc%2FaXep0%2FLf@krava/ Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Suggested-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Cc: Jiri Olsa <olsajiri@gmail.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: David Vernet <void@manifault.com> Acked-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/r/20231031215625.2343848-1-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-10-19bpf, docs: Define signed modulo as using truncated divisionDave Thaler1-0/+8
There's different mathematical definitions (truncated, floored, rounded, etc.) and different languages have chosen different definitions [0][1]. E.g., languages/libraries that follow Knuth use a different mathematical definition than C uses. This patch specifies which definition BPF uses, as verified by Eduard [2] and others. [0] https://en.wikipedia.org/wiki/Modulo#Variants_of_the_definition [1] https://torstencurdt.com/tech/posts/modulo-of-negative-numbers/ [2] https://lore.kernel.org/bpf/57e6fefadaf3b2995bb259fa8e711c7220ce5290.camel@gmail.com/ Signed-off-by: Dave Thaler <dthaler@microsoft.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: David Vernet <void@manifault.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20231017203020.1500-1-dthaler1968@googlemail.com
2023-10-12documentation/bpf: Document cgroup unix socket address hooksDaan De Meyer1-0/+10
Update the documentation to mention the new cgroup unix sockaddr hooks. Signed-off-by: Daan De Meyer <daan.j.demeyer@gmail.com> Link: https://lore.kernel.org/r/20231011185113.140426-8-daan.j.demeyer@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-09-14docs/bpf: update out-of-date doc in BPF flow dissectorQuan Tian1-1/+1
Commit a5e2151ff9d5 ("net/ipv6: SKB symmetric hash should incorporate transport ports") removed the use of FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL in __skb_get_hash_symmetric(), making the doc out-of-date. Signed-off-by: Quan Tian <qtian@vmware.com> Link: https://lore.kernel.org/r/20230911152353.8280-1-qtian@vmware.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-09-08Merge tag 'net-6.6-rc1' of ↵Linus Torvalds7-37/+370
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking updates from Jakub Kicinski: "Including fixes from netfilter and bpf. Current release - regressions: - eth: stmmac: fix failure to probe without MAC interface specified Current release - new code bugs: - docs: netlink: fix missing classic_netlink doc reference Previous releases - regressions: - deal with integer overflows in kmalloc_reserve() - use sk_forward_alloc_get() in sk_get_meminfo() - bpf_sk_storage: fix the missing uncharge in sk_omem_alloc - fib: avoid warn splat in flow dissector after packet mangling - skb_segment: call zero copy functions before using skbuff frags - eth: sfc: check for zero length in EF10 RX prefix Previous releases - always broken: - af_unix: fix msg_controllen test in scm_pidfd_recv() for MSG_CMSG_COMPAT - xsk: fix xsk_build_skb() dereferencing possible ERR_PTR() - netfilter: - nft_exthdr: fix non-linear header modification - xt_u32, xt_sctp: validate user space input - nftables: exthdr: fix 4-byte stack OOB write - nfnetlink_osf: avoid OOB read - one more fix for the garbage collection work from last release - igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU - bpf, sockmap: fix preempt_rt splat when using raw_spin_lock_t - handshake: fix null-deref in handshake_nl_done_doit() - ip: ignore dst hint for multipath routes to ensure packets are hashed across the nexthops - phy: micrel: - correct bit assignments for cable test errata - disable EEE according to the KSZ9477 errata Misc: - docs/bpf: document compile-once-run-everywhere (CO-RE) relocations - Revert "net: macsec: preserve ingress frame ordering", it appears to have been developed against an older kernel, problem doesn't exist upstream" * tag 'net-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (95 commits) net: enetc: distinguish error from valid pointers in enetc_fixup_clear_rss_rfs() Revert "net: team: do not use dynamic lockdep key" net: hns3: remove GSO partial feature bit net: hns3: fix the port information display when sfp is absent net: hns3: fix invalid mutex between tc qdisc and dcb ets command issue net: hns3: fix debugfs concurrency issue between kfree buffer and read net: hns3: fix byte order conversion issue in hclge_dbg_fd_tcam_read() net: hns3: Support query tx timeout threshold by debugfs net: hns3: fix tx timeout issue net: phy: Provide Module 4 KSZ9477 errata (DS80000754C) netfilter: nf_tables: Unbreak audit log reset netfilter: ipset: add the missing IP_SET_HASH_WITH_NET0 macro for ip_set_hash_netportnet.c netfilter: nft_set_rbtree: skip sync GC for new elements in this transaction netfilter: nf_tables: uapi: Describe NFTA_RULE_CHAIN_ID netfilter: nfnetlink_osf: avoid OOB read netfilter: nftables: exthdr: fix 4-byte stack OOB write selftests/bpf: Check bpf_sk_storage has uncharged sk_omem_alloc bpf: bpf_sk_storage: Fix the missing uncharge in sk_omem_alloc bpf: bpf_sk_storage: Fix invalid wait context lockdep report s390/bpf: Pass through tail call counter in trampolines ...
2023-09-01docs/bpf: Fix "file doesn't exist" warnings in {llvm_reloc,btf}.rstEduard Zingerman2-2/+2
scripts/documentation-file-ref-check reports warnings for (valid) cross-links of form: :ref:`Documentation/bpf/btf <BTF_Ext_Section>` Adding extension to the file name helps to avoid the warning, e.g: :ref:`Documentation/bpf/btf.rst <BTF_Ext_Section>` Fixes: be4033d36070 ("docs/bpf: Add description for CO-RE relocations") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Olsa <jolsa@kernel.org> Closes: https://lore.kernel.org/oe-kbuild-all/202309010804.G3MpXo59-lkp@intel.com Link: https://lore.kernel.org/bpf/20230901125935.487972-1-eddyz87@gmail.com
2023-08-31Merge tag 'docs-6.6' of git://git.lwn.net/linuxLinus Torvalds2-2/+2
Pull documentation updates from Jonathan Corbet: "Documentation work keeps chugging along; this includes: - Work from Carlos Bilbao to integrate rustdoc output into the generated HTML documentation. This took some work to figure out how to do it without slowing the docs build and without creating people who don't have Rust installed, but Carlos got there - Move the loongarch and mips architecture documentation under Documentation/arch/ - Some more maintainer documentation from Jakub ... plus the usual assortment of updates, translations, and fixes" * tag 'docs-6.6' of git://git.lwn.net/linux: (56 commits) Docu: genericirq.rst: fix irq-example input: docs: pxrc: remove reference to phoenix-sim Documentation: serial-console: Fix literal block marker docs/mm: remove references to hmm_mirror ops and clean typos docs/zh_CN: correct regi_chg(),regi_add() to region_chg(),region_add() Documentation: Fix typos Documentation/ABI: Fix typos scripts: kernel-doc: fix macro handling in enums scripts: kernel-doc: parse DEFINE_DMA_UNMAP_[ADDR|LEN] Documentation: riscv: Update boot image header since EFI stub is supported Documentation: riscv: Add early boot document Documentation: arm: Add bootargs to the table of added DT parameters docs: kernel-parameters: Refer to the correct bitmap function doc: update params of memhp_default_state= docs: Add book to process/kernel-docs.rst docs: sparse: fix invalid link addresses docs: vfs: clean up after the iterate() removal docs: Add a section on surveys to the researcher guidelines docs: move mips under arch docs: move loongarch under arch ...
2023-08-30bpf, docs: s/eBPF/BPF in standards documentsDavid Vernet1-11/+11
There isn't really anything other than just "BPF" at this point, so referring to it as "eBPF" in our standards document just causes unnecessary confusion. Let's just be consistent and use "BPF". Suggested-by: Will Hawkins <hawkinsw@obs.cr> Signed-off-by: David Vernet <void@manifault.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230828155948.123405-4-void@manifault.com
2023-08-30bpf, docs: Add abi.rst document to standardization subdirectoryDavid Vernet3-16/+26
As specified in the IETF BPF charter, the BPF working group has plans to add one or more informational documents that recommend conventions and guidelines for producing portable BPF program binaries. The instruction-set.rst document currently contains a "Registers and calling convention" subsection which dictates a calling convention that belongs in an ABI document, rather than an instruction set document. Let's move it to a new abi.rst document so we can clean it up. The abi.rst document will of course be significantly changed and expanded upon over time. For now, it's really just a placeholder which will contain ABI-specific language that doesn't belong in other documents. Signed-off-by: David Vernet <void@manifault.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230828155948.123405-3-void@manifault.com
2023-08-30bpf, docs: Move linux-notes.rst to root bpf docs treeDavid Vernet3-1/+1
In commit 4d496be9ca05 ("bpf,docs: Create new standardization subdirectory"), I added a standardization/ directory to the BPF documentation, which will contain the docs that will be standardized as part of the effort with the IETF. I included linux-notes.rst in that directory, but I shouldn't have. It doesn't contain anything that will be standardized. Let's move it back to Documentation/bpf. Signed-off-by: David Vernet <void@manifault.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230828155948.123405-2-void@manifault.com
2023-08-30docs/bpf: Add description for CO-RE relocationsEduard Zingerman2-6/+329
Add a section on CO-RE relocations to llvm_relo.rst. Describe relevant .BTF.ext structure, `enum bpf_core_relo_kind` and `struct bpf_core_relo` in some detail. Description is based on doc-strings from: - include/uapi/linux/bpf.h:struct bpf_core_relo - tools/lib/bpf/relo_core.c:__bpf_core_types_match() Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20230826222912.2560865-2-eddyz87@gmail.com
2023-08-30bpf, docs: Correct source of offset for program-local callWill Hawkins1-3/+3
The offset to use when calculating the target of a program-local call is in the instruction's imm field, not its offset field. Signed-off-by: Will Hawkins <hawkinsw@obs.cr> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230826053258.1860167-1-hawkinsw@obs.cr
2023-08-18Documentation: Fix typosBjorn Helgaas2-2/+2
Fix typos in Documentation. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20230814212822.193684-4-helgaas@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-08-09bpf, docs: Fix small typo and define semantics of sign extensionWill Hawkins1-9/+30
Add additional precision on the semantics of the sign extension operations in BPF. In addition, fix a very minor typo. Signed-off-by: Will Hawkins <hawkinsw@obs.cr> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230808212503.197834-1-hawkinsw@obs.cr Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-08-08bpf, docs: Formalize type notation and function semantics in ISA standardWill Hawkins1-8/+74
Give a single place where the shorthand for types are defined and the semantics of helper functions are described. Signed-off-by: Will Hawkins <hawkinsw@obs.cr> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230807140651.122484-1-hawkinsw@obs.cr Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-07-30docs/bpf: Fix malformed documentationYonghong Song1-21/+24
Two issues are fixed: 1. Malformed table due to newly-introduced BPF_MOVSX 2. Missing reference link for ``Sign-extension load operations`` Fixes: 245d4c40c09b ("docs/bpf: Add documentation for new instructions") Cc: bpf@ietf.org Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202307291840.Cqhj7uox-lkp@intel.com/ Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230730004251.381307-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-29docs/bpf: Improve documentation for cpu=v4 instructionsYonghong Song1-22/+32
Improve documentation for cpu=v4 instructions based on David's suggestions. Cc: bpf@ietf.org Suggested-by: David Vernet <void@manifault.com> Acked-by: David Vernet <void@manifault.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230728225105.919595-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-28docs/bpf: Add documentation for new instructionsYonghong Song2-41/+79
Add documentation in instruction-set.rst for new instruction encoding and their corresponding operations. Also removed the question related to 'no BPF_SDIV' in bpf_design_QA.rst since we have BPF_SDIV insn now. Cc: bpf@ietf.org Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230728011342.3724411-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-28bpf, docs: fix BPF_NEG entry in instruction-set.rstJose E. Marchesi1-1/+1
This patch fixes the documentation of the BPF_NEG instruction to denote that it does not use the source register operand. Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com> Acked-by: Dave Thaler <dthaler@microsoft.com> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20230726092543.6362-1-jose.marchesi@oracle.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-11bpf,docs: Create new standardization subdirectoryDavid Vernet4-3/+21
The BPF standardization effort is actively underway with the IETF. As described in the BPF Working Group (WG) charter in [0], there are a number of proposed documents, some informational and some proposed standards, that will be drafted as part of the standardization effort. [0]: https://datatracker.ietf.org/wg/bpf/about/ Though the specific documents that will formally be standardized will exist as Internet Drafts (I-D) and WG documents in the BPF WG datatracker page, the source of truth from where those documents will be generated will reside in the kernel documentation tree (originating in the bpf-next tree). Because these documents will be used to generate the I-D and WG documents which will be standardized with the IETF, they are a bit special as far as kernel-tree documentation goes: - They will be dual licensed with LGPL-2.1 OR BSD-2-Clause - IETF I-D and WG documents (the documents which will actually be standardized) will be auto-generated from these documents. In order to keep things clearly organized in the BPF documentation tree, and to make it abundantly clear where standards-related documentation needs to go, we should move standards-relevant documents into a separate standardization/ subdirectory. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230710183027.15132-1-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-06-29bpf, docs: Fix definition of BPF_NEG operationDave Thaler1-1/+1
Instruction is an arithmetic negative, not a bitwise inverse. Signed-off-by: Dave Thaler <dthaler@microsoft.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230627213912.951-1-dthaler1968@googlemail.com
2023-06-29bpf: Replace deprecated -target with --target= for ClangFangrui Song3-10/+10
The -target option has been deprecated since clang 3.4 in 2013. Therefore, use the preferred --target=bpf form instead. This also matches how we use --target= in scripts/Makefile.clang. Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://github.com/llvm/llvm-project/commit/274b6f0c87a6a1798de0a68135afc7f95def6277 Link: https://lore.kernel.org/bpf/20230624001856.1903733-1-maskray@google.com
2023-06-25sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)David Howells1-5/+5
Remove ->sendpage() and ->sendpage_locked(). sendmsg() with MSG_SPLICE_PAGES should be used instead. This allows multiple pages and multipage folios to be passed through. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for net/can cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> cc: linux-afs@lists.infradead.org cc: mptcp@lists.linux.dev cc: rds-devel@oss.oracle.com cc: tipc-discussion@lists.sourceforge.net cc: virtualization@lists.linux-foundation.org Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-22bpf, docs: Document existing macros instead of deprecatedAnton Protopopov1-6/+32
The BTF_TYPE_SAFE_NESTED macro was replaced by the BTF_TYPE_SAFE_TRUSTED, BTF_TYPE_SAFE_RCU, and BTF_TYPE_SAFE_RCU_OR_NULL macros. Fix the docs correspondingly. Fixes: 6fcd486b3a0a ("bpf: Refactor RCU enforcement in the verifier.") Signed-off-by: Anton Protopopov <aspsk@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20230622095424.1024244-1-aspsk@isovalent.com
2023-06-22bpf, docs: BPF Iterator DocumentAnton Protopopov1-5/+2
Fix the description of the seq_info field of the bpf_iter_reg structure which was wrong due to an accidental copy/paste of the previous field's description. Fixes: 8972e18a439d ("bpf, docs: BPF Iterator Document") Signed-off-by: Anton Protopopov <aspsk@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20230622095407.1024053-1-aspsk@isovalent.com
2023-06-13bpf/docs: Update documentation for new cpumask kfuncsDavid Vernet1-2/+3
We recently added the bpf_cpumask_first_and() kfunc, and changed bpf_cpumask_any() / bpf_cpumask_any_and() to bpf_cpumask_any_distribute() and bpf_cpumask_any_distribute_and() respectively. This patch adds an entry for the bpf_cpumask_first_and() kfunc, and updates the documentation for the *any* kfuncs to the new names. Signed-off-by: David Vernet <void@manifault.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20230610035053.117605-5-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-17bpf, docs: Shift operations are defined to use a maskDave Thaler1-3/+6
Update the documentation regarding shift operations to explain the use of a mask, since otherwise shifting by a value out of range (like negative) is undefined. Signed-off-by: Dave Thaler <dthaler@microsoft.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20230509180845.1236-1-dthaler1968@googlemail.com
2023-05-17Merge tag 'for-netdev' of ↵Jakub Kicinski5-11/+312
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2023-05-16 We've added 57 non-merge commits during the last 19 day(s) which contain a total of 63 files changed, 3293 insertions(+), 690 deletions(-). The main changes are: 1) Add precision propagation to verifier for subprogs and callbacks, from Andrii Nakryiko. 2) Improve BPF's {g,s}setsockopt() handling with wrong option lengths, from Stanislav Fomichev. 3) Utilize pahole v1.25 for the kernel's BTF generation to filter out inconsistent function prototypes, from Alan Maguire. 4) Various dyn-pointer verifier improvements to relax restrictions, from Daniel Rosenberg. 5) Add a new bpf_task_under_cgroup() kfunc for designated task, from Feng Zhou. 6) Unblock tests for arm64 BPF CI after ftrace supporting direct call, from Florent Revest. 7) Add XDP hint kfunc metadata for RX hash/timestamp for igc, from Jesper Dangaard Brouer. 8) Add several new dyn-pointer kfuncs to ease their usability, from Joanne Koong. 9) Add in-depth LRU internals description and dot function graph, from Joe Stringer. 10) Fix KCSAN report on bpf_lru_list when accessing node->ref, from Martin KaFai Lau. 11) Only dump unprivileged_bpf_disabled log warning upon write, from Kui-Feng Lee. 12) Extend test_progs to directly passing allow/denylist file, from Stephen Veiss. 13) Fix BPF trampoline memleak upon failure attaching to fentry, from Yafang Shao. 14) Fix emitting struct bpf_tcp_sock type in vmlinux BTF, from Yonghong Song. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (57 commits) bpf: Fix memleak due to fentry attach failure bpf: Remove bpf trampoline selector bpf, arm64: Support struct arguments in the BPF trampoline bpftool: JIT limited misreported as negative value on aarch64 bpf: fix calculation of subseq_idx during precision backtracking bpf: Remove anonymous union in bpf_kfunc_call_arg_meta bpf: Document EFAULT changes for sockopt selftests/bpf: Correctly handle optlen > 4096 selftests/bpf: Update EFAULT {g,s}etsockopt selftests bpf: Don't EFAULT for {g,s}setsockopt with wrong optlen libbpf: fix offsetof() and container_of() to work with CO-RE bpf: Address KCSAN report on bpf_lru_list bpf: Add --skip_encoding_btf_inconsistent_proto, --btf_gen_optimized to pahole flags for v1.25 selftests/bpf: Accept mem from dynptr in helper funcs bpf: verifier: Accept dynptr mem as mem in helpers selftests/bpf: Check overflow in optional buffer selftests/bpf: Test allowing NULL buffer in dynptr slice bpf: Allow NULL buffers in bpf_dynptr_slice(_rw) selftests/bpf: Add testcase for bpf_task_under_cgroup bpf: Add bpf_task_under_cgroup() kfunc ... ==================== Link: https://lore.kernel.org/r/20230515225603.27027-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-14bpf: Document EFAULT changes for sockoptStanislav Fomichev1-1/+56
And add examples for how to correctly handle large optlens. This is less relevant now when we don't EFAULT anymore, but that's still the correct thing to do. Signed-off-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20230511170456.1759459-5-sdf@google.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-05-07bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)Daniel Rosenberg1-1/+22
bpf_dynptr_slice(_rw) uses a user provided buffer if it can not provide a pointer to a block of contiguous memory. This buffer is unused in the case of local dynptrs, and may be unused in other cases as well. There is no need to require the buffer, as the kfunc can just return NULL if it was needed and not provided. This adds another kfunc annotation, __opt, which combines with __sz and __szk to allow the buffer associated with the size to be NULL. If the buffer is NULL, the verifier does not check that the buffer is of sufficient size. Signed-off-by: Daniel Rosenberg <drosen@google.com> Link: https://lore.kernel.org/r/20230506013134.2492210-2-drosen@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-05bpf, docs: Update llvm_relocs.rst with typo fixesWill Hawkins1-8/+10
Correct a few typographical errors and fix some mistakes in examples. Signed-off-by: Will Hawkins <hawkinsw@obs.cr> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20230428023015.1698072-2-hawkinsw@obs.cr Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-29Merge tag 'lsm-pr-20230428' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm Pull lsm fix from Paul Moore: "A single Documentation/LSM fix to update the LSM hook documentation references from lsm_hooks.h to security.c" * tag 'lsm-pr-20230428' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: lsm: move hook comments docs to security/security.c
2023-04-28lsm: move hook comments docs to security/security.cRandy Dunlap1-1/+1
Fix one kernel-doc warning, but invesigating that led to other kernel-doc movement (lsm_hooks.h to security.c) that needs to be fixed also. include/linux/lsm_hooks.h:1: warning: no structured comments found Fixes: e261301c851a ("lsm: move the remaining LSM hook comments to security/security.c") Fixes: 1cd2aca64a5d ("lsm: move the io_uring hook comments to security/security.c") Fixes: 452b670c7222 ("lsm: move the perf hook comments to security/security.c") Fixes: 55e853201a9e ("lsm: move the bpf hook comments to security/security.c") Fixes: b14faf9c94a6 ("lsm: move the audit hook comments to security/security.c") Fixes: 1427ddbe5cc1 ("lsm: move the binder hook comments to security/security.c") Fixes: 43fad2821876 ("lsm: move the sysv hook comments to security/security.c") Fixes: ecc419a44535 ("lsm: move the key hook comments to security/security.c") Fixes: 742b99456e86 ("lsm: move the xfrm hook comments to security/security.c") Fixes: ac318aed5498 ("lsm: move the Infiniband hook comments to security/security.c") Fixes: 4a49f592e931 ("lsm: move the SCTP hook comments to security/security.c") Fixes: 6b6bbe8c02a1 ("lsm: move the socket hook comments to security/security.c") Fixes: 2c2442fd46cd ("lsm: move the AF_UNIX hook comments to security/security.c") Fixes: 2bcf51bf2f03 ("lsm: move the netlink hook comments to security/security.c") Fixes: 130c53bfee4b ("lsm: move the task hook comments to security/security.c") Fixes: a0fd6480de48 ("lsm: move the file hook comments to security/security.c") Fixes: 9348944b775d ("lsm: move the kernfs hook comments to security/security.c") Fixes: 916e32584dfa ("lsm: move the inode hook comments to security/security.c") Fixes: 08526a902cc4 ("lsm: move the filesystem hook comments to security/security.c") Fixes: 36819f185590 ("lsm: move the fs_context hook comments to security/security.c") Fixes: 1661372c912d ("lsm: move the program execution hook comments to security/security.c") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Paul Moore <paul@paul-moore.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: linux-security-module@vger.kernel.org Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: KP Singh <kpsingh@kernel.org> Cc: bpf@vger.kernel.org Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-04-27docs/bpf: Add LRU internals description and graphJoe Stringer2-0/+214
Extend the bpf hashmap docs to include a brief description of the internals of the LRU map type (setting appropriate API expectations), including the original commit message from Martin and a variant on the graph that I had presented during my Linux Plumbers Conference 2022 talk on "Pressure feedback for LRU map types"[0]. The node names in the dot file correspond roughly to the functions where the logic for those decisions or steps is defined, to help curious developers to cross-reference and update this logic if the details of the LRU implementation ever differ from this description. [0] https://lpc.events/event/16/contributions/1368/ Signed-off-by: Joe Stringer <joe@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20230422172054.3355436-2-joe@isovalent.com
2023-04-27docs/bpf: Add table to describe LRU propertiesJoe Stringer1-1/+10
Depending on the map type and flags for LRU, different properties are global or percpu. Add a table to describe these. Signed-off-by: Joe Stringer <joe@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20230422172054.3355436-1-joe@isovalent.com
2023-04-16bpf,docs: Remove KF_KPTR_GET from documentationDavid Vernet1-15/+6
A prior patch removed KF_KPTR_GET from the kernel. Now that it's no longer accessible to kfunc authors, this patch removes it from the BPF kfunc documentation. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230416084928.326135-4-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-14Daniel Borkmann says:Jakub Kicinski8-141/+451
==================== pull-request: bpf-next 2023-04-13 We've added 260 non-merge commits during the last 36 day(s) which contain a total of 356 files changed, 21786 insertions(+), 11275 deletions(-). The main changes are: 1) Rework BPF verifier log behavior and implement it as a rotating log by default with the option to retain old-style fixed log behavior, from Andrii Nakryiko. 2) Adds support for using {FOU,GUE} encap with an ipip device operating in collect_md mode and add a set of BPF kfuncs for controlling encap params, from Christian Ehrig. 3) Allow BPF programs to detect at load time whether a particular kfunc exists or not, and also add support for this in light skeleton, from Alexei Starovoitov. 4) Optimize hashmap lookups when key size is multiple of 4, from Anton Protopopov. 5) Enable RCU semantics for task BPF kptrs and allow referenced kptr tasks to be stored in BPF maps, from David Vernet. 6) Add support for stashing local BPF kptr into a map value via bpf_kptr_xchg(). This is useful e.g. for rbtree node creation for new cgroups, from Dave Marchevsky. 7) Fix BTF handling of is_int_ptr to skip modifiers to work around tracing issues where a program cannot be attached, from Feng Zhou. 8) Migrate a big portion of test_verifier unit tests over to test_progs -a verifier_* via inline asm to ease {read,debug}ability, from Eduard Zingerman. 9) Several updates to the instruction-set.rst documentation which is subject to future IETF standardization (https://lwn.net/Articles/926882/), from Dave Thaler. 10) Fix BPF verifier in the __reg_bound_offset's 64->32 tnum sub-register known bits information propagation, from Daniel Borkmann. 11) Add skb bitfield compaction work related to BPF with the overall goal to make more of the sk_buff bits optional, from Jakub Kicinski. 12) BPF selftest cleanups for build id extraction which stand on its own from the upcoming integration work of build id into struct file object, from Jiri Olsa. 13) Add fixes and optimizations for xsk descriptor validation and several selftest improvements for xsk sockets, from Kal Conley. 14) Add BPF links for struct_ops and enable switching implementations of BPF TCP cong-ctls under a given name by replacing backing struct_ops map, from Kui-Feng Lee. 15) Remove a misleading BPF verifier env->bypass_spec_v1 check on variable offset stack read as earlier Spectre checks cover this, from Luis Gerhorst. 16) Fix issues in copy_from_user_nofault() for BPF and other tracers to resemble copy_from_user_nmi() from safety PoV, from Florian Lehner and Alexei Starovoitov. 17) Add --json-summary option to test_progs in order for CI tooling to ease parsing of test results, from Manu Bretelle. 18) Batch of improvements and refactoring to prep for upcoming bpf_local_storage conversion to bpf_mem_cache_{alloc,free} allocator, from Martin KaFai Lau. 19) Improve bpftool's visual program dump which produces the control flow graph in a DOT format by adding C source inline annotations, from Quentin Monnet. 20) Fix attaching fentry/fexit/fmod_ret/lsm to modules by extracting the module name from BTF of the target and searching kallsyms of the correct module, from Viktor Malik. 21) Improve BPF verifier handling of '<const> <cond> <non_const>' to better detect whether in particular jmp32 branches are taken, from Yonghong Song. 22) Allow BPF TCP cong-ctls to write app_limited of struct tcp_sock. A built-in cc or one from a kernel module is already able to write to app_limited, from Yixin Shen. Conflicts: Documentation/bpf/bpf_devel_QA.rst b7abcd9c656b ("bpf, doc: Link to submitting-patches.rst for general patch submission info") 0f10f647f455 ("bpf, docs: Use internal linking for link to netdev subsystem doc") https://lore.kernel.org/all/20230307095812.236eb1be@canb.auug.org.au/ include/net/ip_tunnels.h bc9d003dc48c3 ("ip_tunnel: Preserve pointer const in ip_tunnel_info_opts") ac931d4cdec3d ("ipip,ip_tunnel,sit: Add FOU support for externally controlled ipip devices") https://lore.kernel.org/all/20230413161235.4093777-1-broonie@kernel.org/ net/bpf/test_run.c e5995bc7e2ba ("bpf, test_run: fix crashes due to XDP frame overwriting/corruption") 294635a8165a ("bpf, test_run: fix &xdp_frame misplacement for LIVE_FRAMES") https://lore.kernel.org/all/20230320102619.05b80a98@canb.auug.org.au/ ==================== Link: https://lore.kernel.org/r/20230413191525.7295-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-12bpf,docs: Remove references to bpf_cgroup_kptr_get()David Vernet1-68/+0
The bpf_cgroup_kptr_get() kfunc has been removed, and bpf_cgroup_acquire() / bpf_cgroup_release() now have the same semantics as bpf_task_acquire() / bpf_task_release(). This patch updates the BPF documentation to reflect this. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230411041633.179404-3-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-03bpf, docs: Add docs on extended 64-bit immediate instructionsDave Thaler2-8/+72
Add docs on extended 64-bit immediate instructions, including six instructions previously undocumented. Include a brief description of maps and variables, as used by those instructions. V1 -> V2: rebased on top of latest master V2 -> V3: addressed comments from Alexei V3 -> V4: addressed comments from David Vernet Signed-off-by: Dave Thaler <dthaler@microsoft.com> Link: https://lore.kernel.org/r/20230326054946.2331-1-dthaler1968@googlemail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-01bpf,docs: Update documentation to reflect new task kfuncsDavid Vernet1-6/+43
Now that struct task_struct objects are RCU safe, and bpf_task_acquire() can return NULL, we should update the BPF task kfunc documentation to reflect the current state of the API. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230331195733.699708-4-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-26bpf, docs: Add extended call instructionsDave Thaler1-22/+37
Add extended call instructions. Uses the term "program-local" for call by offset. And there are instructions for calling helper functions by "address" (the old way of using integer values), and for calling helper functions by BTF ID (for kfuncs). V1 -> V2: addressed comments from David Vernet V2 -> V3: make descriptions in table consistent with updated names V3 -> V4: addressed comments from Alexei V4 -> V5: fixed alignment Signed-off-by: Dave Thaler <dthaler@microsoft.com> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230326033117.1075-1-dthaler1968@googlemail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-26bpf: Treat KF_RELEASE kfuncs as KF_TRUSTED_ARGSDavid Vernet1-3/+4
KF_RELEASE kfuncs are not currently treated as having KF_TRUSTED_ARGS, even though they have a superset of the requirements of KF_TRUSTED_ARGS. Like KF_TRUSTED_ARGS, KF_RELEASE kfuncs require a 0-offset argument, and don't allow NULL-able arguments. Unlike KF_TRUSTED_ARGS which require _either_ an argument with ref_obj_id > 0, _or_ (ref->type & BPF_REG_TRUSTED_MODIFIERS) (and no unsafe modifiers allowed), KF_RELEASE only allows for ref_obj_id > 0. Because KF_RELEASE today doesn't automatically imply KF_TRUSTED_ARGS, some of these requirements are enforced in different ways that can make the behavior of the verifier feel unpredictable. For example, a KF_RELEASE kfunc with a NULL-able argument will currently fail in the verifier with a message like, "arg#0 is ptr_or_null_ expected ptr_ or socket" rather than "Possibly NULL pointer passed to trusted arg0". Our intention is the same, but the semantics are different due to implemenetation details that kfunc authors and BPF program writers should not need to care about. Let's make the behavior of the verifier more consistent and intuitive by having KF_RELEASE kfuncs imply the presence of KF_TRUSTED_ARGS. Our eventual goal is to have all kfuncs assume KF_TRUSTED_ARGS by default anyways, so this takes us a step in that direction. Note that it does not make sense to assume KF_TRUSTED_ARGS for all KF_ACQUIRE kfuncs. KF_ACQUIRE kfuncs can have looser semantics than KF_RELEASE, with e.g. KF_RCU | KF_RET_NULL. We may want to have KF_ACQUIRE imply KF_TRUSTED_ARGS _unless_ KF_RCU is specified, but that can be left to another patch set, and there are no such subtleties to address for KF_RELEASE. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230325213144.486885-4-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-18bpf, docs: Libbpf overview documentationSreevani Sreejith2-8/+245
This patch documents overview of libbpf, including its features for developing BPF programs. Signed-off-by: Sreevani Sreejith <ssreevani@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230315195405.2051559-1-ssreevani@meta.com
2023-03-17bpf, docs: Use internal linking for link to netdev subsystem docBagas Sanjaya1-8/+12
Commit d56b0c461d19da ("bpf, docs: Fix link to netdev-FAQ target") attempts to fix linking problem to undefined "netdev-FAQ" label introduced in 287f4fa99a5281 ("docs: Update references to netdev-FAQ") by changing internal cross reference to netdev subsystem documentation (Documentation/process/maintainer-netdev.rst) to external one at docs.kernel.org. However, the linking problem is still not resolved, as the generated link points to non-existent netdev-FAQ section of the external doc, which when clicked, will instead going to the top of the doc. Revert back to internal linking by simply mention the doc path while massaging the leading text to the link, since the netdev subsystem doc contains no FAQs but rather general information about the subsystem. Fixes: d56b0c461d19 ("bpf, docs: Fix link to netdev-FAQ target") Fixes: 287f4fa99a52 ("docs: Update references to netdev-FAQ") Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230314074449.23620-1-bagasdotme@gmail.com
2023-03-16bpf,docs: Remove bpf_cpumask_kptr_get() from documentationDavid Vernet1-20/+10
Now that the kfunc no longer exists, we can remove it and instead describe how RCU can be used to get a struct bpf_cpumask from a map value. This patch updates the BPF documentation accordingly. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230316054028.88924-6-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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