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 > > 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 > >> >> > >> >> [...]
