Messages in this thread Patch in this message | | | Date | Thu, 3 Jan 2019 23:41:18 +0100 | From | Heiko Carstens <> | Subject | Re: "bpf: Improve the info.func_info and info.func_info_rec_size behavior" breaks strace self tests |
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On Thu, Jan 03, 2019 at 07:12:05PM +0000, Martin Lau wrote: > On Thu, Jan 03, 2019 at 12:46:13PM +0100, Heiko Carstens wrote: > > Hello, > > > > the kernel commit 7337224fc150 ("bpf: Improve the info.func_info and > > info.func_info_rec_size behavior") breaks one of strace's self tests: > > > > FAIL: bpf-obj_get_info_by_fd-prog-v.gen > The strace's bpf-obj_get_info_by_fd-prog-v test did fail. However, > I failed to see how 7337224fc150 broke it. How do you trace down to > commit 7337224fc150 and can you share your test output? > > The failure I can reproduce is EFAULT. It should have been failing > as early as "nr_jited_ksyms" is added to "struct bpf_prog_info" > in linux/bpf.h.
Ah, sorry(!), I forgot to mention an important detail: the test failure happens only if executed as normal (non-root) user.
With 7337224fc150 ("bpf: Improve the info.func_info and info.func_info_rec_size behavior") the failure happens. With commit 30da46b5dc3a ("tools: bpftool: add a command to dump the trace pipe") it passes; which is one commit earlier.
FAIL: bpf-obj_get_info_by_fd-prog-v.gen =======================================
--- exp 2019-01-03 23:31:49.576949303 +0100 +++ log 2019-01-03 23:31:49.576949303 +0100 @@ -1,8 +1,8 @@ bpf(BPF_MAP_CREATE, {map_type=BPF_MAP_TYPE_ARRAY, key_size=4, value_size=8, max_entries=1, map_flags=0, inner_map_fd=0</dev/null>, map_name="test_map", map_ifindex=0}, 48) = 3<anon_inode:bpf-map> bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_SOCKET_FILTER, insn_cnt=9, insns=[{code=BPF_ALU64|BPF_K|BPF_MOV, dst_reg=BPF_REG_1, src_reg=BPF_REG_0, off=0, imm=0}, {code=BPF_STX|BPF_W|BPF_MEM, dst_reg=BPF_REG_10, src_reg=BPF_REG_1, off=-4, imm=0}, {code=BPF_ALU64|BPF_X|BPF_MOV, dst_reg=BPF_REG_2, src_reg=BPF_REG_10, off=0, imm=0}, {code=BPF_ALU64|BPF_K|BPF_ADD, dst_reg=BPF_REG_2, src_reg=BPF_REG_0, off=0, imm=0xfffffffc}, {code=BPF_LD|BPF_DW|BPF_IMM, dst_reg=BPF_REG_1, src_reg=BPF_REG_1, off=0, imm=0x3}, {code=BPF_LD|BPF_W|BPF_IMM, dst_reg=BPF_REG_0, src_reg=BPF_REG_0, off=0, imm=0}, {code=BPF_JMP|BPF_K|BPF_CALL, dst_reg=BPF_REG_0, src_reg=BPF_REG_0, off=0, imm=0x1}, {code=BPF_ALU64|BPF_K|BPF_MOV, dst_reg=BPF_REG_0, src_reg=BPF_REG_0, off=0, imm=0}, {code=BPF_JMP|BPF_K|BPF_EXIT, dst_reg=BPF_REG_0, src_reg=BPF_REG_0, off=0, imm=0}], license="BSD", log_level=42, log_size=4096, log_buf="", kern_version=KERNEL_VERSION(57005, 192, 222), prog_flags=0, prog_name="test_prog", prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS}, 72) = 4<anon_inode:bpf-prog> bpf(BPF_OBJ_GET_INFO_BY_FD, {info={bpf_fd=3<anon_inode:bpf-map>, info_len=128 => 80, info={type=BPF_MAP_TYPE_ARRAY, id=15, key_size=4, value_size=8, max_entries=1, map_flags=0, name="test_map", ifindex=0, netns_dev=makedev(0, 0), netns_ino=0}}}, 16) = 0 -bpf(BPF_OBJ_GET_INFO_BY_FD, {info={bpf_fd=4<anon_inode:bpf-prog>, info_len=168 => 152, info={type=BPF_PROG_TYPE_SOCKET_FILTER, id=8, tag="\xde\x90\x83\x18\xfb\x16\xd8\x9c", jited_prog_len=0, jited_prog_insns=NULL, xlated_prog_len=0, xlated_prog_insns=NULL, load_time=28281352029, created_by_uid=1000, nr_map_ids=0 => 1, map_ids=NULL, name="test_prog", ifindex=0, netns_dev=makedev(0, 0), netns_ino=0}}}, 16) = 0 -bpf(BPF_OBJ_GET_INFO_BY_FD, {info={bpf_fd=4<anon_inode:bpf-prog>, info_len=152, info={type=BPF_PROG_TYPE_SOCKET_FILTER, id=8, tag="\xde\x90\x83\x18\xfb\x16\xd8\x9c", jited_prog_len=0, jited_prog_insns=NULL, xlated_prog_len=336, xlated_prog_insns=0x3ff8d6f7000, load_time=28281352029, created_by_uid=1000, nr_map_ids=2, map_ids=0x3ff8d6f1000, name="test_prog", ifindex=0, netns_dev=makedev(0, 0), netns_ino=0}}}, 16) = -1 EFAULT (Bad address) -bpf(BPF_OBJ_GET_INFO_BY_FD, {info={bpf_fd=4<anon_inode:bpf-prog>, info_len=152, info={type=BPF_PROG_TYPE_SOCKET_FILTER, id=8, tag="\xde\x90\x83\x18\xfb\x16\xd8\x9c", jited_prog_len=0, jited_prog_insns=NULL, xlated_prog_len=0, xlated_prog_insns=[], load_time=28281352029, created_by_uid=1000, nr_map_ids=0 => 1, map_ids=[], name="test_prog", ifindex=0, netns_dev=makedev(0, 0), netns_ino=0}}}, 16) = 0 -bpf(BPF_OBJ_GET_INFO_BY_FD, {info={bpf_fd=4<anon_inode:bpf-prog>, info_len=152, info={type=BPF_PROG_TYPE_SOCKET_FILTER, id=8, tag="\xde\x90\x83\x18\xfb\x16\xd8\x9c", jited_prog_len=0, jited_prog_insns=NULL, xlated_prog_len=0, xlated_prog_insns=[], load_time=28281352029, created_by_uid=1000, nr_map_ids=2 => 1, map_ids=[15], name="test_prog", ifindex=0, netns_dev=makedev(0, 0), netns_ino=0}}}, 16) = 0 +bpf(BPF_OBJ_GET_INFO_BY_FD, {info={bpf_fd=4<anon_inode:bpf-prog>, info_len=168 => 152, info={type=BPF_PROG_TYPE_SOCKET_FILTER, id=8, tag="\xde\x90\x83\x18\xfb\x16\xd8\x9c", jited_prog_len=0, jited_prog_insns=NULL, xlated_prog_len=0, xlated_prog_insns=NULL, load_time=28281352029, created_by_uid=1000, nr_map_ids=0 => 1, map_ids=NULL, name="test_prog", ifindex=0, netns_dev=makedev(0, 0), netns_ino=0, /* bytes 104..151 */ "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}}}, 16) = 0 +bpf(BPF_OBJ_GET_INFO_BY_FD, {info={bpf_fd=4<anon_inode:bpf-prog>, info_len=152, info={type=BPF_PROG_TYPE_SOCKET_FILTER, id=8, tag="\xde\x90\x83\x18\xfb\x16\xd8\x9c", jited_prog_len=0, jited_prog_insns=NULL, xlated_prog_len=336, xlated_prog_insns=0x3ff8d6f7000, load_time=28281352029, created_by_uid=1000, nr_map_ids=2, map_ids=0x3ff8d6f1000, name="test_prog", ifindex=0, netns_dev=makedev(0, 0), netns_ino=0, /* bytes 104..151 */ "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}}}, 16) = -1 EFAULT (Bad address) +bpf(BPF_OBJ_GET_INFO_BY_FD, {info={bpf_fd=4<anon_inode:bpf-prog>, info_len=152, info={type=BPF_PROG_TYPE_SOCKET_FILTER, id=8, tag="\xde\x90\x83\x18\xfb\x16\xd8\x9c", jited_prog_len=0, jited_prog_insns=NULL, xlated_prog_len=0, xlated_prog_insns=[], load_time=28281352029, created_by_uid=1000, nr_map_ids=0 => 1, map_ids=[], name="test_prog", ifindex=0, netns_dev=makedev(0, 0), netns_ino=0, /* bytes 104..151 */ "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}}}, 16) = 0 +bpf(BPF_OBJ_GET_INFO_BY_FD, {info={bpf_fd=4<anon_inode:bpf-prog>, info_len=152, info={type=BPF_PROG_TYPE_SOCKET_FILTER, id=8, tag="\xde\x90\x83\x18\xfb\x16\xd8\x9c", jited_prog_len=0, jited_prog_insns=NULL, xlated_prog_len=0, xlated_prog_insns=[], load_time=28281352029, created_by_uid=1000, nr_map_ids=2 => 1, map_ids=[15], name="test_prog", ifindex=0, netns_dev=makedev(0, 0), netns_ino=0, /* bytes 104..151 */ "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"}}}, 16) = 0 +++ exited with 0 +++ bpf-obj_get_info_by_fd-prog-v.gen.test: failed test: ../../strace -a20 -y -v -e trace=bpf ../bpf-obj_get_info_by_fd-prog-v output mismatch FAIL bpf-obj_get_info_by_fd-prog-v.gen.test (exit status: 1)
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