> On Sat, Jul 9, 2022 at 11:24 AM Jose E. Marchesi > <jose.marchesi@xxxxxxxxxx> wrote: >> >> >> > On Fri, Jul 8, 2022 at 12:33 PM Jose E. Marchesi >> > <jose.marchesi@xxxxxxxxxx> wrote: >> >> >> >> >> >> >> On Wed, Jul 6, 2022 at 10:13 AM James Hilliard >> >> >> <james.hilliard1@xxxxxxxxx> wrote: >> >> >>> >> >> >>> Note I'm testing with the following patches: >> >> >>> https://lore.kernel.org/bpf/20220706111839.1247911-1-james.hilliard1@xxxxxxxxx/ >> >> >>> https://lore.kernel.org/bpf/20220706140623.2917858-1-james.hilliard1@xxxxxxxxx/ >> >> >>> >> >> >>> It would appear there's some compatibility issues with bpftool gen and >> >> >>> GCC, not sure what side though is wrong here: >> >> >>> /home/buildroot/buildroot/output/per-package/systemd/host/sbin/bpftool >> >> >>> gen object src/core/bpf/restrict_ifaces/restrict-ifaces.bpf.o >> >> >>> src/core/bpf/restrict_ifaces/restrict-ifaces.bpf.unstripped.o >> >> >>> libbpf: failed to find BTF info for global/extern symbol 'sd_restrictif_i' >> >> >>> Error: failed to link >> >> >>> 'src/core/bpf/restrict_ifaces/restrict-ifaces.bpf.unstripped.o': >> >> >>> Unknown error -2 (-2) >> >> >>> >> >> >>> Relevant difference seems to be this: >> >> >>> GCC: >> >> >>> [55] FUNC 'sd_restrictif_i' type_id=47 linkage=static >> >> >>> Clang: >> >> >>> [27] FUNC 'sd_restrictif_i' type_id=26 linkage=global >> >> > >> >> > For functions GCC generates a BTF_KIND_FUNC entry, which has no linkage >> >> > information, or so we thought: I just looked at bpftool/btf.c and I >> >> > found the linkage info for function types is expected to be encoded in >> >> > the vlen field of BTF_KIND_FUNC entries (why not adding a btf_func >> >> > instead???) which is surprising to say the least. >> >> > >> >> > We are changing GCC to encode the linkage info in vlen for these types. >> >> > Thanks for reporting this. >> >> >> >> Patch sent to GCC upstream: >> >> https://gcc.gnu.org/pipermail/gcc-patches/2022-July/598090.html >> > >> > I applied that patch on top of GCC 12.1.0 and it appears to fix the >> > bpftool gen object bug. >> > >> > I am however now hitting a different error during skeleton generation: >> > /home/buildroot/buildroot/output/per-package/systemd/host/sbin/bpftool >> > gen skeleton src/core/bpf/restrict_ifaces/restrict-ifaces.bpf.o >> > libbpf: elf: skipping unrecognized data section(9) .comment >> > libbpf: failed to alloc map 'restrict.bss' content buffer: -22 >> > Error: failed to open BPF object file: Invalid argument >> >> What is the size of the .bss section in the object file? Try with: >> >> $ size restrict-ifaces.bpf.o > > $ size output/build/systemd-custom/build/src/core/bpf/restrict_ifaces/restrict-ifaces.bpf.o > text data bss dec hex filename > 386 25 0 411 19b > output/build/systemd-custom/build/src/core/bpf/restrict_ifaces/restrict-ifaces.bpf.o Right, so the .bss section is empty. I see a `const volatile unsigned char is_allow_list = 0;' in restrict-ifaces.bpf.c, but that goes to .data and not to .bss, as expected. If you build restrict-ifaces.bpf.o with LLVM, is the bss still empty? I don't think the code in libbpf.c even checks for this eventuality... >> >> Looking at libbpf.c, it seems to me that this may be due of trying to >> mmap 0 bytes in `bpf_object__init_internal_map': >> >> map->mmaped = mmap(NULL, bpf_map_mmap_sz(map), PROT_READ | PROT_WRITE, >> MAP_SHARED | MAP_ANONYMOUS, -1, 0); >> if (map->mmaped == MAP_FAILED) { >> err = -errno; >> map->mmaped = NULL; >> pr_warn("failed to alloc map '%s' content buffer: %d\n", >> map->name, err); >> zfree(&map->real_name); >> zfree(&map->name); >> return err; >> } >> >> I see no check for zero sized sections in >> bpf_object__init_global_data_maps. >> >> Is maybe GCC failing to allocate stuff in BSS that is supposed to be >> there? >> >> > Stripped file passed to gen skeleton: >> > /home/buildroot/buildroot/output/per-package/systemd/host/sbin/bpftool >> > btf dump file >> > output/build/systemd-custom/build/src/core/bpf/restrict_ifaces/restrict-ifaces.bpf.o >> > format raw >> > [1] INT 'signed char' size=1 bits_offset=0 nr_bits=8 encoding=UNKN >> > [2] INT 'unsigned char' size=1 bits_offset=0 nr_bits=8 encoding=CHAR >> > [3] TYPEDEF '__u8' type_id=2 >> > [4] CONST '(anon)' type_id=3 >> > [5] VOLATILE '(anon)' type_id=4 >> > [6] INT 'short int' size=2 bits_offset=0 nr_bits=16 encoding=SIGNED >> > [7] INT 'short unsigned int' size=2 bits_offset=0 nr_bits=16 encoding=(none) >> > [8] TYPEDEF '__u16' type_id=7 >> > [9] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED >> > [10] TYPEDEF '__s32' type_id=9 >> > [11] INT 'unsigned int' size=4 bits_offset=0 nr_bits=32 encoding=(none) >> > [12] TYPEDEF '__u32' type_id=11 >> > [13] INT 'long long int' size=8 bits_offset=0 nr_bits=64 encoding=SIGNED >> > [14] INT 'long long unsigned int' size=8 bits_offset=0 nr_bits=64 >> > encoding=(none) >> > [15] TYPEDEF '__u64' type_id=14 >> > [16] INT 'long unsigned int' size=8 bits_offset=0 nr_bits=64 encoding=(none) >> > [17] INT 'long int' size=8 bits_offset=0 nr_bits=64 encoding=SIGNED >> > [18] INT 'char' size=1 bits_offset=0 nr_bits=8 encoding=UNKN >> > [19] CONST '(anon)' type_id=18 >> > [20] TYPEDEF '__be16' type_id=8 >> > [21] TYPEDEF '__be32' type_id=12 >> > [22] ENUM 'bpf_map_type' encoding=UNSIGNED size=4 vlen=31 >> > 'BPF_MAP_TYPE_UNSPEC' val=0 >> > 'BPF_MAP_TYPE_HASH' val=1 >> > 'BPF_MAP_TYPE_ARRAY' val=2 >> > 'BPF_MAP_TYPE_PROG_ARRAY' val=3 >> > 'BPF_MAP_TYPE_PERF_EVENT_ARRAY' val=4 >> > 'BPF_MAP_TYPE_PERCPU_HASH' val=5 >> > 'BPF_MAP_TYPE_PERCPU_ARRAY' val=6 >> > 'BPF_MAP_TYPE_STACK_TRACE' val=7 >> > 'BPF_MAP_TYPE_CGROUP_ARRAY' val=8 >> > 'BPF_MAP_TYPE_LRU_HASH' val=9 >> > 'BPF_MAP_TYPE_LRU_PERCPU_HASH' val=10 >> > 'BPF_MAP_TYPE_LPM_TRIE' val=11 >> > 'BPF_MAP_TYPE_ARRAY_OF_MAPS' val=12 >> > 'BPF_MAP_TYPE_HASH_OF_MAPS' val=13 >> > 'BPF_MAP_TYPE_DEVMAP' val=14 >> > 'BPF_MAP_TYPE_SOCKMAP' val=15 >> > 'BPF_MAP_TYPE_CPUMAP' val=16 >> > 'BPF_MAP_TYPE_XSKMAP' val=17 >> > 'BPF_MAP_TYPE_SOCKHASH' val=18 >> > 'BPF_MAP_TYPE_CGROUP_STORAGE' val=19 >> > 'BPF_MAP_TYPE_REUSEPORT_SOCKARRAY' val=20 >> > 'BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE' val=21 >> > 'BPF_MAP_TYPE_QUEUE' val=22 >> > 'BPF_MAP_TYPE_STACK' val=23 >> > 'BPF_MAP_TYPE_SK_STORAGE' val=24 >> > 'BPF_MAP_TYPE_DEVMAP_HASH' val=25 >> > 'BPF_MAP_TYPE_STRUCT_OPS' val=26 >> > 'BPF_MAP_TYPE_RINGBUF' val=27 >> > 'BPF_MAP_TYPE_INODE_STORAGE' val=28 >> > 'BPF_MAP_TYPE_TASK_STORAGE' val=29 >> > 'BPF_MAP_TYPE_BLOOM_FILTER' val=30 >> > [23] UNION '(anon)' size=8 vlen=1 >> > 'flow_keys' type_id=29 bits_offset=0 >> > [24] STRUCT 'bpf_flow_keys' size=56 vlen=13 >> > 'nhoff' type_id=8 bits_offset=0 >> > 'thoff' type_id=8 bits_offset=16 >> > 'addr_proto' type_id=8 bits_offset=32 >> > 'is_frag' type_id=3 bits_offset=48 >> > 'is_first_frag' type_id=3 bits_offset=56 >> > 'is_encap' type_id=3 bits_offset=64 >> > 'ip_proto' type_id=3 bits_offset=72 >> > 'n_proto' type_id=20 bits_offset=80 >> > 'sport' type_id=20 bits_offset=96 >> > 'dport' type_id=20 bits_offset=112 >> > '(anon)' type_id=25 bits_offset=128 >> > 'flags' type_id=12 bits_offset=384 >> > 'flow_label' type_id=21 bits_offset=416 >> > [25] UNION '(anon)' size=32 vlen=2 >> > '(anon)' type_id=26 bits_offset=0 >> > '(anon)' type_id=27 bits_offset=0 >> > [26] STRUCT '(anon)' size=8 vlen=2 >> > 'ipv4_src' type_id=21 bits_offset=0 >> > 'ipv4_dst' type_id=21 bits_offset=32 >> > [27] STRUCT '(anon)' size=32 vlen=2 >> > 'ipv6_src' type_id=28 bits_offset=0 >> > 'ipv6_dst' type_id=28 bits_offset=128 >> > [28] ARRAY '(anon)' type_id=12 index_type_id=16 nr_elems=4 >> > [29] PTR '(anon)' type_id=24 >> > [30] UNION '(anon)' size=8 vlen=1 >> > 'sk' type_id=32 bits_offset=0 >> > [31] STRUCT 'bpf_sock' size=80 vlen=14 >> > 'bound_dev_if' type_id=12 bits_offset=0 >> > 'family' type_id=12 bits_offset=32 >> > 'type' type_id=12 bits_offset=64 >> > 'protocol' type_id=12 bits_offset=96 >> > 'mark' type_id=12 bits_offset=128 >> > 'priority' type_id=12 bits_offset=160 >> > 'src_ip4' type_id=12 bits_offset=192 >> > 'src_ip6' type_id=28 bits_offset=224 >> > 'src_port' type_id=12 bits_offset=352 >> > 'dst_port' type_id=20 bits_offset=384 >> > 'dst_ip4' type_id=12 bits_offset=416 >> > 'dst_ip6' type_id=28 bits_offset=448 >> > 'state' type_id=12 bits_offset=576 >> > 'rx_queue_mapping' type_id=10 bits_offset=608 >> > [32] PTR '(anon)' type_id=31 >> > [33] STRUCT '__sk_buff' size=192 vlen=33 >> > 'len' type_id=12 bits_offset=0 >> > 'pkt_type' type_id=12 bits_offset=32 >> > 'mark' type_id=12 bits_offset=64 >> > 'queue_mapping' type_id=12 bits_offset=96 >> > 'protocol' type_id=12 bits_offset=128 >> > 'vlan_present' type_id=12 bits_offset=160 >> > 'vlan_tci' type_id=12 bits_offset=192 >> > 'vlan_proto' type_id=12 bits_offset=224 >> > 'priority' type_id=12 bits_offset=256 >> > 'ingress_ifindex' type_id=12 bits_offset=288 >> > 'ifindex' type_id=12 bits_offset=320 >> > 'tc_index' type_id=12 bits_offset=352 >> > 'cb' type_id=34 bits_offset=384 >> > 'hash' type_id=12 bits_offset=544 >> > 'tc_classid' type_id=12 bits_offset=576 >> > 'data' type_id=12 bits_offset=608 >> > 'data_end' type_id=12 bits_offset=640 >> > 'napi_id' type_id=12 bits_offset=672 >> > 'family' type_id=12 bits_offset=704 >> > 'remote_ip4' type_id=12 bits_offset=736 >> > 'local_ip4' type_id=12 bits_offset=768 >> > 'remote_ip6' type_id=28 bits_offset=800 >> > 'local_ip6' type_id=28 bits_offset=928 >> > 'remote_port' type_id=12 bits_offset=1056 >> > 'local_port' type_id=12 bits_offset=1088 >> > 'data_meta' type_id=12 bits_offset=1120 >> > '(anon)' type_id=23 bits_offset=1152 >> > 'tstamp' type_id=15 bits_offset=1216 >> > 'wire_len' type_id=12 bits_offset=1280 >> > 'gso_segs' type_id=12 bits_offset=1312 >> > '(anon)' type_id=30 bits_offset=1344 >> > 'gso_size' type_id=12 bits_offset=1408 >> > 'hwtstamp' type_id=15 bits_offset=1472 >> > [34] ARRAY '(anon)' type_id=12 index_type_id=16 nr_elems=5 >> > [35] CONST '(anon)' type_id=33 >> > [36] PTR '(anon)' type_id=0 >> > [37] STRUCT '(anon)' size=24 vlen=3 >> > 'type' type_id=39 bits_offset=0 >> > 'key' type_id=40 bits_offset=64 >> > 'value' type_id=41 bits_offset=128 >> > [38] ARRAY '(anon)' type_id=9 index_type_id=16 nr_elems=1 >> > [39] PTR '(anon)' type_id=38 >> > [40] PTR '(anon)' type_id=12 >> > [41] PTR '(anon)' type_id=3 >> > [42] ARRAY '(anon)' type_id=19 index_type_id=16 nr_elems=18 >> > [43] CONST '(anon)' type_id=42 >> > [44] FUNC_PROTO '(anon)' ret_type_id=36 vlen=2 >> > '(anon)' type_id=36 >> > '(anon)' type_id=46 >> > [45] CONST '(anon)' type_id=0 >> > [46] PTR '(anon)' type_id=45 >> > [47] FUNC_PROTO '(anon)' ret_type_id=9 vlen=1 >> > 'sk' type_id=48 >> > [48] PTR '(anon)' type_id=35 >> > [49] VAR '_license' type_id=43, linkage=static >> > [50] VAR 'is_allow_list' type_id=5, linkage=global >> > [51] VAR 'sd_restrictif' type_id=37, linkage=global >> > [52] FUNC 'sd_restrictif_i' type_id=47 linkage=global >> > [53] FUNC 'sd_restrictif_e' type_id=47 linkage=global >> > [54] FUNC 'restrict_network_interfaces_impl' type_id=47 linkage=static >> > [55] DATASEC '.data' size=1 vlen=1 >> > type_id=50 offset=0 size=1 (VAR 'is_allow_list') >> > [56] DATASEC 'license' size=18 vlen=1 >> > type_id=49 offset=0 size=18 (VAR '_license') >> > [57] DATASEC '.maps' size=24 vlen=1 >> > type_id=51 offset=0 size=24 (VAR 'sd_restrictif') >> > >> > File before being stripped using bpftool gen object: >> > /home/buildroot/buildroot/output/per-package/systemd/host/sbin/bpftool >> > btf dump file >> > output/build/systemd-custom/build/src/core/bpf/restrict_ifaces/restrict-ifaces.bpf.unstripped.o >> > format raw >> > [1] INT 'signed char' size=1 bits_offset=0 nr_bits=8 encoding=UNKN >> > [2] INT 'unsigned char' size=1 bits_offset=0 nr_bits=8 encoding=CHAR >> > [3] TYPEDEF '__u8' type_id=2 >> > [4] CONST '(anon)' type_id=3 >> > [5] VOLATILE '(anon)' type_id=4 >> > [6] INT 'short int' size=2 bits_offset=0 nr_bits=16 encoding=SIGNED >> > [7] INT 'short unsigned int' size=2 bits_offset=0 nr_bits=16 encoding=(none) >> > [8] TYPEDEF '__u16' type_id=7 >> > [9] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED >> > [10] TYPEDEF '__s32' type_id=9 >> > [11] INT 'unsigned int' size=4 bits_offset=0 nr_bits=32 encoding=(none) >> > [12] TYPEDEF '__u32' type_id=11 >> > [13] INT 'long long int' size=8 bits_offset=0 nr_bits=64 encoding=SIGNED >> > [14] INT 'long long unsigned int' size=8 bits_offset=0 nr_bits=64 >> > encoding=(none) >> > [15] TYPEDEF '__u64' type_id=14 >> > [16] INT 'long unsigned int' size=8 bits_offset=0 nr_bits=64 encoding=(none) >> > [17] INT 'long int' size=8 bits_offset=0 nr_bits=64 encoding=SIGNED >> > [18] INT 'char' size=1 bits_offset=0 nr_bits=8 encoding=UNKN >> > [19] CONST '(anon)' type_id=18 >> > [20] TYPEDEF '__be16' type_id=8 >> > [21] TYPEDEF '__be32' type_id=12 >> > [22] ENUM 'bpf_map_type' encoding=UNSIGNED size=4 vlen=31 >> > 'BPF_MAP_TYPE_UNSPEC' val=0 >> > 'BPF_MAP_TYPE_HASH' val=1 >> > 'BPF_MAP_TYPE_ARRAY' val=2 >> > 'BPF_MAP_TYPE_PROG_ARRAY' val=3 >> > 'BPF_MAP_TYPE_PERF_EVENT_ARRAY' val=4 >> > 'BPF_MAP_TYPE_PERCPU_HASH' val=5 >> > 'BPF_MAP_TYPE_PERCPU_ARRAY' val=6 >> > 'BPF_MAP_TYPE_STACK_TRACE' val=7 >> > 'BPF_MAP_TYPE_CGROUP_ARRAY' val=8 >> > 'BPF_MAP_TYPE_LRU_HASH' val=9 >> > 'BPF_MAP_TYPE_LRU_PERCPU_HASH' val=10 >> > 'BPF_MAP_TYPE_LPM_TRIE' val=11 >> > 'BPF_MAP_TYPE_ARRAY_OF_MAPS' val=12 >> > 'BPF_MAP_TYPE_HASH_OF_MAPS' val=13 >> > 'BPF_MAP_TYPE_DEVMAP' val=14 >> > 'BPF_MAP_TYPE_SOCKMAP' val=15 >> > 'BPF_MAP_TYPE_CPUMAP' val=16 >> > 'BPF_MAP_TYPE_XSKMAP' val=17 >> > 'BPF_MAP_TYPE_SOCKHASH' val=18 >> > 'BPF_MAP_TYPE_CGROUP_STORAGE' val=19 >> > 'BPF_MAP_TYPE_REUSEPORT_SOCKARRAY' val=20 >> > 'BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE' val=21 >> > 'BPF_MAP_TYPE_QUEUE' val=22 >> > 'BPF_MAP_TYPE_STACK' val=23 >> > 'BPF_MAP_TYPE_SK_STORAGE' val=24 >> > 'BPF_MAP_TYPE_DEVMAP_HASH' val=25 >> > 'BPF_MAP_TYPE_STRUCT_OPS' val=26 >> > 'BPF_MAP_TYPE_RINGBUF' val=27 >> > 'BPF_MAP_TYPE_INODE_STORAGE' val=28 >> > 'BPF_MAP_TYPE_TASK_STORAGE' val=29 >> > 'BPF_MAP_TYPE_BLOOM_FILTER' val=30 >> > [23] UNION '(anon)' size=8 vlen=1 >> > 'flow_keys' type_id=29 bits_offset=0 >> > [24] STRUCT 'bpf_flow_keys' size=56 vlen=13 >> > 'nhoff' type_id=8 bits_offset=0 >> > 'thoff' type_id=8 bits_offset=16 >> > 'addr_proto' type_id=8 bits_offset=32 >> > 'is_frag' type_id=3 bits_offset=48 >> > 'is_first_frag' type_id=3 bits_offset=56 >> > 'is_encap' type_id=3 bits_offset=64 >> > 'ip_proto' type_id=3 bits_offset=72 >> > 'n_proto' type_id=20 bits_offset=80 >> > 'sport' type_id=20 bits_offset=96 >> > 'dport' type_id=20 bits_offset=112 >> > '(anon)' type_id=25 bits_offset=128 >> > 'flags' type_id=12 bits_offset=384 >> > 'flow_label' type_id=21 bits_offset=416 >> > [25] UNION '(anon)' size=32 vlen=2 >> > '(anon)' type_id=26 bits_offset=0 >> > '(anon)' type_id=27 bits_offset=0 >> > [26] STRUCT '(anon)' size=8 vlen=2 >> > 'ipv4_src' type_id=21 bits_offset=0 >> > 'ipv4_dst' type_id=21 bits_offset=32 >> > [27] STRUCT '(anon)' size=32 vlen=2 >> > 'ipv6_src' type_id=28 bits_offset=0 >> > 'ipv6_dst' type_id=28 bits_offset=128 >> > [28] ARRAY '(anon)' type_id=12 index_type_id=16 nr_elems=4 >> > [29] PTR '(anon)' type_id=24 >> > [30] UNION '(anon)' size=8 vlen=1 >> > 'sk' type_id=32 bits_offset=0 >> > [31] STRUCT 'bpf_sock' size=80 vlen=14 >> > 'bound_dev_if' type_id=12 bits_offset=0 >> > 'family' type_id=12 bits_offset=32 >> > 'type' type_id=12 bits_offset=64 >> > 'protocol' type_id=12 bits_offset=96 >> > 'mark' type_id=12 bits_offset=128 >> > 'priority' type_id=12 bits_offset=160 >> > 'src_ip4' type_id=12 bits_offset=192 >> > 'src_ip6' type_id=28 bits_offset=224 >> > 'src_port' type_id=12 bits_offset=352 >> > 'dst_port' type_id=20 bits_offset=384 >> > 'dst_ip4' type_id=12 bits_offset=416 >> > 'dst_ip6' type_id=28 bits_offset=448 >> > 'state' type_id=12 bits_offset=576 >> > 'rx_queue_mapping' type_id=10 bits_offset=608 >> > [32] PTR '(anon)' type_id=31 >> > [33] STRUCT '__sk_buff' size=192 vlen=33 >> > 'len' type_id=12 bits_offset=0 >> > 'pkt_type' type_id=12 bits_offset=32 >> > 'mark' type_id=12 bits_offset=64 >> > 'queue_mapping' type_id=12 bits_offset=96 >> > 'protocol' type_id=12 bits_offset=128 >> > 'vlan_present' type_id=12 bits_offset=160 >> > 'vlan_tci' type_id=12 bits_offset=192 >> > 'vlan_proto' type_id=12 bits_offset=224 >> > 'priority' type_id=12 bits_offset=256 >> > 'ingress_ifindex' type_id=12 bits_offset=288 >> > 'ifindex' type_id=12 bits_offset=320 >> > 'tc_index' type_id=12 bits_offset=352 >> > 'cb' type_id=34 bits_offset=384 >> > 'hash' type_id=12 bits_offset=544 >> > 'tc_classid' type_id=12 bits_offset=576 >> > 'data' type_id=12 bits_offset=608 >> > 'data_end' type_id=12 bits_offset=640 >> > 'napi_id' type_id=12 bits_offset=672 >> > 'family' type_id=12 bits_offset=704 >> > 'remote_ip4' type_id=12 bits_offset=736 >> > 'local_ip4' type_id=12 bits_offset=768 >> > 'remote_ip6' type_id=28 bits_offset=800 >> > 'local_ip6' type_id=28 bits_offset=928 >> > 'remote_port' type_id=12 bits_offset=1056 >> > 'local_port' type_id=12 bits_offset=1088 >> > 'data_meta' type_id=12 bits_offset=1120 >> > '(anon)' type_id=23 bits_offset=1152 >> > 'tstamp' type_id=15 bits_offset=1216 >> > 'wire_len' type_id=12 bits_offset=1280 >> > 'gso_segs' type_id=12 bits_offset=1312 >> > '(anon)' type_id=30 bits_offset=1344 >> > 'gso_size' type_id=12 bits_offset=1408 >> > 'hwtstamp' type_id=15 bits_offset=1472 >> > [34] ARRAY '(anon)' type_id=12 index_type_id=16 nr_elems=5 >> > [35] CONST '(anon)' type_id=33 >> > [36] PTR '(anon)' type_id=0 >> > [37] STRUCT '(anon)' size=24 vlen=3 >> > 'type' type_id=39 bits_offset=0 >> > 'key' type_id=40 bits_offset=64 >> > 'value' type_id=41 bits_offset=128 >> > [38] ARRAY '(anon)' type_id=9 index_type_id=16 nr_elems=1 >> > [39] PTR '(anon)' type_id=38 >> > [40] PTR '(anon)' type_id=12 >> > [41] PTR '(anon)' type_id=3 >> > [42] ARRAY '(anon)' type_id=19 index_type_id=16 nr_elems=18 >> > [43] CONST '(anon)' type_id=42 >> > [44] FUNC_PROTO '(anon)' ret_type_id=36 vlen=2 >> > '(anon)' type_id=36 >> > '(anon)' type_id=46 >> > [45] CONST '(anon)' type_id=0 >> > [46] PTR '(anon)' type_id=45 >> > [47] FUNC_PROTO '(anon)' ret_type_id=9 vlen=1 >> > 'sk' type_id=48 >> > [48] PTR '(anon)' type_id=35 >> > [49] FUNC_PROTO '(anon)' ret_type_id=9 vlen=1 >> > 'sk' type_id=48 >> > [50] FUNC_PROTO '(anon)' ret_type_id=9 vlen=1 >> > 'sk' type_id=48 >> > [51] VAR '_license' type_id=43, linkage=static >> > [52] VAR 'is_allow_list' type_id=5, linkage=global >> > [53] VAR 'sd_restrictif' type_id=37, linkage=global >> > [54] FUNC 'bpf_map_lookup_elem' type_id=44 linkage=global >> > [55] FUNC 'sd_restrictif_i' type_id=47 linkage=global >> > [56] FUNC 'sd_restrictif_e' type_id=49 linkage=global >> > [57] FUNC 'restrict_network_interfaces_impl' type_id=50 linkage=static >> > [58] DATASEC 'license' size=0 vlen=1 >> > type_id=51 offset=0 size=18 (VAR '_license') >> > [59] DATASEC '.maps' size=0 vlen=1 >> > type_id=53 offset=0 size=24 (VAR 'sd_restrictif') >> > [60] DATASEC '.data' size=0 vlen=1 >> > type_id=52 offset=0 size=1 (VAR 'is_allow_list') >> > >> >> >> >> >> GCC is wrong, clearly. This function is global ([0]) and libbpf >> >> >> expects it to be marked as such in BTF. >> >> >> >> >> >> >> > https://github.com/systemd/systemd/blob/main/src/core/bpf/restrict_ifaces/restrict-ifaces.bpf.c#L42-L50 >> >> >> >> >> >> >> >> >>> GCC: >> >> >>> >> >> >>> [1] INT 'signed char' size=1 bits_offset=0 nr_bits=8 encoding=UNKN >> >> >>> [2] INT 'unsigned char' size=1 bits_offset=0 nr_bits=8 encoding=CHAR >> >> >>> [3] TYPEDEF '__u8' type_id=2 >> >> >>> [4] CONST '(anon)' type_id=3 >> >> >> >> >> >> [...]
