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authorLinus Torvalds <torvalds@linux-foundation.org>2023-09-07 18:33:07 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-09-07 18:33:07 -0700
commit73be7fb14e83d24383f840a22f24d3ed222ca319 (patch)
treec03cb0058aa829aca0b30cad5e82f400e4561a00 /Documentation/bpf/btf.rst
parent2ab35ce202f8ba56d4b0930985426214341638a7 (diff)
parent1b36955cc048c8ff6ba448dbf4be0e52f59f2963 (diff)
Merge tag 'net-6.6-rc1' of 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 ...
Diffstat (limited to 'Documentation/bpf/btf.rst')
-rw-r--r--Documentation/bpf/btf.rst31
1 files changed, 25 insertions, 6 deletions
diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst
index f32db1f44ae9..e43c2fdafcd7 100644
--- a/Documentation/bpf/btf.rst
+++ b/Documentation/bpf/btf.rst
@@ -726,8 +726,8 @@ same as the one describe in :ref:`BTF_Type_String`.
4.2 .BTF.ext section
--------------------
-The .BTF.ext section encodes func_info and line_info which needs loader
-manipulation before loading into the kernel.
+The .BTF.ext section encodes func_info, line_info and CO-RE relocations
+which needs loader manipulation before loading into the kernel.
The specification for .BTF.ext section is defined at ``tools/lib/bpf/btf.h``
and ``tools/lib/bpf/btf.c``.
@@ -745,15 +745,20 @@ The current header of .BTF.ext section::
__u32 func_info_len;
__u32 line_info_off;
__u32 line_info_len;
+
+ /* optional part of .BTF.ext header */
+ __u32 core_relo_off;
+ __u32 core_relo_len;
};
It is very similar to .BTF section. Instead of type/string section, it
-contains func_info and line_info section. See :ref:`BPF_Prog_Load` for details
-about func_info and line_info record format.
+contains func_info, line_info and core_relo sub-sections.
+See :ref:`BPF_Prog_Load` for details about func_info and line_info
+record format.
The func_info is organized as below.::
- func_info_rec_size
+ func_info_rec_size /* __u32 value */
btf_ext_info_sec for section #1 /* func_info for section #1 */
btf_ext_info_sec for section #2 /* func_info for section #2 */
...
@@ -773,7 +778,7 @@ Here, num_info must be greater than 0.
The line_info is organized as below.::
- line_info_rec_size
+ line_info_rec_size /* __u32 value */
btf_ext_info_sec for section #1 /* line_info for section #1 */
btf_ext_info_sec for section #2 /* line_info for section #2 */
...
@@ -787,6 +792,20 @@ kernel API, the ``insn_off`` is the instruction offset in the unit of ``struct
bpf_insn``. For ELF API, the ``insn_off`` is the byte offset from the
beginning of section (``btf_ext_info_sec->sec_name_off``).
+The core_relo is organized as below.::
+
+ core_relo_rec_size /* __u32 value */
+ btf_ext_info_sec for section #1 /* core_relo for section #1 */
+ btf_ext_info_sec for section #2 /* core_relo for section #2 */
+
+``core_relo_rec_size`` specifies the size of ``bpf_core_relo``
+structure when .BTF.ext is generated. All ``bpf_core_relo`` structures
+within a single ``btf_ext_info_sec`` describe relocations applied to
+section named by ``btf_ext_info_sec->sec_name_off``.
+
+See :ref:`Documentation/bpf/llvm_reloc.rst <btf-co-re-relocations>`
+for more information on CO-RE relocations.
+
4.2 .BTF_ids section
--------------------