kernel/linux.git/tools/lib/bpf, branch v6.4.4

libbpf: fix offsetof() and container_of() to work with CO-RE

2023-07-19T14:35:23+00:00

[ Upstream commit bdeeed3498c7871c17465bb4f11d1bc67f9098af ] It seems like __builtin_offset() doesn't preserve CO-RE field relocations properly. So if offsetof() macro is defined through __builtin_offset(), CO-RE-enabled BPF code using container_of() will be subtly and silently broken. To avoid this problem, redefine offsetof() and container_of() in the form that works with CO-RE relocations more reliably. Fixes: 5fbc220862fc ("tools/libpf: Add offsetof/container_of macro in bpf_helpers.h") Reported-by: Lennart Poettering Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20230509065502.2306180-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

libbpf: btf_dump_type_data_check_overflow needs to consider BTF_MEMBER_BITFIELD_SIZE

2023-07-19T14:35:21+00:00

[ Upstream commit c39028b333f3a3a765c5c0b9726b8e38aedf0ba1 ] The btf_dump/struct_data selftest is failing with: [...] test_btf_dump_struct_data:FAIL:unexpected return value dumping fs_context unexpected unexpected return value dumping fs_context: actual -7 != expected 264 [...] The reason is in btf_dump_type_data_check_overflow(). It does not use BTF_MEMBER_BITFIELD_SIZE from the struct's member (btf_member). Instead, it is using the enum size which is 4. It had been working till the recent commit 4e04143c869c ("fs_context: drop the unused lsm_flags member") removed an integer member which also removed the 4 bytes padding at the end of the fs_context. Missing this 4 bytes padding exposed this bug. In particular, when btf_dump_type_data_check_overflow() reaches the member 'phase', -E2BIG is returned. The fix is to pass bit_sz to btf_dump_type_data_check_overflow(). In btf_dump_type_data_check_overflow(), it does a different size check when bit_sz is not zero. The current fs_context: [3600] ENUM 'fs_context_purpose' encoding=UNSIGNED size=4 vlen=3 'FS_CONTEXT_FOR_MOUNT' val=0 'FS_CONTEXT_FOR_SUBMOUNT' val=1 'FS_CONTEXT_FOR_RECONFIGURE' val=2 [3601] ENUM 'fs_context_phase' encoding=UNSIGNED size=4 vlen=7 'FS_CONTEXT_CREATE_PARAMS' val=0 'FS_CONTEXT_CREATING' val=1 'FS_CONTEXT_AWAITING_MOUNT' val=2 'FS_CONTEXT_AWAITING_RECONF' val=3 'FS_CONTEXT_RECONF_PARAMS' val=4 'FS_CONTEXT_RECONFIGURING' val=5 'FS_CONTEXT_FAILED' val=6 [3602] STRUCT 'fs_context' size=264 vlen=21 'ops' type_id=3603 bits_offset=0 'uapi_mutex' type_id=235 bits_offset=64 'fs_type' type_id=872 bits_offset=1216 'fs_private' type_id=21 bits_offset=1280 'sget_key' type_id=21 bits_offset=1344 'root' type_id=781 bits_offset=1408 'user_ns' type_id=251 bits_offset=1472 'net_ns' type_id=984 bits_offset=1536 'cred' type_id=1785 bits_offset=1600 'log' type_id=3621 bits_offset=1664 'source' type_id=42 bits_offset=1792 'security' type_id=21 bits_offset=1856 's_fs_info' type_id=21 bits_offset=1920 'sb_flags' type_id=20 bits_offset=1984 'sb_flags_mask' type_id=20 bits_offset=2016 's_iflags' type_id=20 bits_offset=2048 'purpose' type_id=3600 bits_offset=2080 bitfield_size=8 'phase' type_id=3601 bits_offset=2088 bitfield_size=8 'need_free' type_id=67 bits_offset=2096 bitfield_size=1 'global' type_id=67 bits_offset=2097 bitfield_size=1 'oldapi' type_id=67 bits_offset=2098 bitfield_size=1 Fixes: 920d16af9b42 ("libbpf: BTF dumper support for typed data") Signed-off-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20230428013638.1581263-1-martin.lau@linux.dev Signed-off-by: Sasha Levin

bpf: netfilter: Add BPF_NETFILTER bpf_attach_type

2023-06-05T22:01:43+00:00

Andrii Nakryiko writes: And we currently don't have an attach type for NETLINK BPF link. Thankfully it's not too late to add it. I see that link_create() in kernel/bpf/syscall.c just bypasses attach_type check. We shouldn't have done that. Instead we need to add BPF_NETLINK attach type to enum bpf_attach_type. And wire all that properly throughout the kernel and libbpf itself. This adds BPF_NETFILTER and uses it. This breaks uabi but this wasn't in any non-rc release yet, so it should be fine. v2: check link_attack prog type in link_create too Fixes: 84601d6ee68a ("bpf: add bpf_link support for BPF_NETFILTER programs") Suggested-by: Andrii Nakryiko Signed-off-by: Florian Westphal Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/CAEf4BzZ69YgrQW7DHCJUT_X+GqMq_ZQQPBwopaJJVGFD5=d5Vg@mail.gmail.com/ Link: https://lore.kernel.org/bpf/20230605131445.32016-1-fw@strlen.de

Merge tag 'mm-nonmm-stable-2023-04-27-16-01' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-04-28T02:57:00+00:00

Pull non-MM updates from Andrew Morton: "Mainly singleton patches all over the place. Series of note are: - updates to scripts/gdb from Glenn Washburn - kexec cleanups from Bjorn Helgaas" * tag 'mm-nonmm-stable-2023-04-27-16-01' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (50 commits) mailmap: add entries for Paul Mackerras libgcc: add forward declarations for generic library routines mailmap: add entry for Oleksandr ocfs2: reduce ioctl stack usage fs/proc: add Kthread flag to /proc/$pid/status ia64: fix an addr to taddr in huge_pte_offset() checkpatch: introduce proper bindings license check epoll: rename global epmutex scripts/gdb: add GDB convenience functions $lx_dentry_name() and $lx_i_dentry() scripts/gdb: create linux/vfs.py for VFS related GDB helpers uapi/linux/const.h: prefer ISO-friendly __typeof__ delayacct: track delays from IRQ/SOFTIRQ scripts/gdb: timerlist: convert int chunks to str scripts/gdb: print interrupts scripts/gdb: raise error with reduced debugging information scripts/gdb: add a Radix Tree Parser lib/rbtree: use '+' instead of '|' for setting color. proc/stat: remove arch_idle_time() checkpatch: check for misuse of the link tags checkpatch: allow Closes tags with links ...

tools: bpftool: print netfilter link info

2023-04-21T18:34:49+00:00

Dump protocol family, hook and priority value: $ bpftool link 2: netfilter prog 14 ip input prio -128 pids install(3264) 5: netfilter prog 14 ip6 forward prio 21 pids a.out(3387) 9: netfilter prog 14 ip prerouting prio 123 pids a.out(5700) 10: netfilter prog 14 ip input prio 21 pids test2(5701) v2: Quentin Monnet suggested to also add 'bpftool net' support: $ bpftool net xdp: tc: flow_dissector: netfilter: ip prerouting prio 21 prog_id 14 ip input prio -128 prog_id 14 ip input prio 21 prog_id 14 ip forward prio 21 prog_id 14 ip output prio 21 prog_id 14 ip postrouting prio 21 prog_id 14 'bpftool net' only dumps netfilter link type, links are sorted by protocol family, hook and priority. v5: fix bpf ci failure: libbpf needs small update to prog_type_name[] and probe_prog_load helper. v4: don't fail with -EOPNOTSUPP in libbpf probe_prog_load, update prog_type_name[] with "netfilter" entry (bpf ci) v3: fix bpf.h copy, 'reserved' member was removed (Alexei) use p_err, not fprintf (Quentin) Suggested-by: Quentin Monnet Link: https://lore.kernel.org/bpf/eeeaac99-9053-90c2-aa33-cc1ecb1ae9ca@isovalent.com/ Reviewed-by: Quentin Monnet Signed-off-by: Florian Westphal Link: https://lore.kernel.org/r/20230421170300.24115-6-fw@strlen.de Signed-off-by: Alexei Starovoitov

libbpf: mark bpf_iter_num_{new,next,destroy} as __weak

2023-04-18T19:45:11+00:00

Mark bpf_iter_num_{new,next,destroy}() kfuncs declared for bpf_for()/bpf_repeat() macros as __weak to allow users to feature-detect their presence and guard bpf_for()/bpf_repeat() loops accordingly for backwards compatibility with old kernels. Now that libbpf supports kfunc calls poisoning and better reporting of unresolved (but called) kfuncs, declaring number iterator kfuncs in bpf_helpers.h won't degrade user experience and won't cause unnecessary kernel feature dependencies. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20230418002148.3255690-7-andrii@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: move bpf_for(), bpf_for_each(), and bpf_repeat() into bpf_helpers.h

2023-04-18T19:45:11+00:00

To make it easier for bleeding-edge BPF applications, such as sched_ext, to utilize open-coded iterators, move bpf_for(), bpf_for_each(), and bpf_repeat() macros from selftests/bpf-internal bpf_misc.h helper, to libbpf-provided bpf_helpers.h header. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20230418002148.3255690-6-andrii@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: improve handling of unresolved kfuncs

2023-04-18T19:45:10+00:00

Currently, libbpf leaves `call #0` instruction for __weak unresolved kfuncs, which might lead to a confusing verifier log situations, where invalid `call #0` will be treated as successfully validated. We can do better. Libbpf already has an established mechanism of poisoning instructions that failed some form of resolution (e.g., CO-RE relocation and BPF map set to not be auto-created). Libbpf doesn't fail them outright to allow users to guard them through other means, and as long as BPF verifier can prove that such poisoned instructions cannot be ever reached, this doesn't consistute an invalid BPF program. If user didn't guard such code, libbpf will extract few pieces of information to tie such poisoned instructions back to additional information about what entitity wasn't resolved (e.g., BPF map name, or CO-RE relocation information). __weak unresolved kfuncs fit this model well, so this patch extends libbpf with poisioning and log fixup logic for kfunc calls. Note, this poisoning is done only for kfunc *calls*, not kfunc address resolution (ldimm64 instructions). The former cannot be ever valid, if reached, so it's safe to poison them. The latter is a valid mechanism to check if __weak kfunc ksym was resolved, and do necessary guarding and work arounds based on this result, supported in most recent kernels. As such, libbpf keeps such ldimm64 instructions as loading zero, never poisoning them. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20230418002148.3255690-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: report vmlinux vs module name when dealing with ksyms

2023-04-18T19:45:10+00:00

Currently libbpf always reports "kernel" as a source of ksym BTF type, which is ambiguous given ksym's BTF can come from either vmlinux or kernel module BTFs. Make this explicit and log module name, if used BTF is from kernel module. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20230418002148.3255690-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: misc internal libbpf clean ups around log fixup

2023-04-18T19:45:10+00:00

Normalize internal constants, field names, and comments related to log fixup. Also add explicit `ext_idx` alias for relocation where relocation is pointing to extern description for additional information. No functional changes, just a clean up before subsequent additions. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20230418002148.3255690-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov