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2020-01-25selftest/bpf: Add test for allowed trampolines countJiri Olsa1-0/+21
There's limit of 40 programs tht can be attached to trampoline for one function. Adding test that tries to attach that many plus one extra that needs to fail. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200123161508.915203-4-jolsa@kernel.org
2020-01-24selftests: bpf: Ignore FIN packets for reuseport testsLorenz Bauer1-0/+6
The reuseport tests currently suffer from a race condition: FIN packets count towards DROP_ERR_SKB_DATA, since they don't contain a valid struct cmd. Tests will spuriously fail depending on whether check_results is called before or after the FIN is processed. Exit the BPF program early if FIN is set. Fixes: 91134d849a0e ("bpf: Test BPF_PROG_TYPE_SK_REUSEPORT") Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200124112754.19664-3-lmb@cloudflare.com
2020-01-22bpf: tcp: Add bpf_cubic exampleMartin KaFai Lau1-0/+544
This patch adds a bpf_cubic example. Some highlights: 1. CONFIG_HZ .kconfig map is used. 2. In bictcp_update(), calculation is changed to use usec resolution (i.e. USEC_PER_JIFFY) instead of using jiffies. Thus, usecs_to_jiffies() is not used in the bpf_cubic.c. 3. In bitctcp_update() [under tcp_friendliness], the original "while (ca->ack_cnt > delta)" loop is changed to the equivalent "ca->ack_cnt / delta" operation. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200122233658.903774-1-kafai@fb.com
2020-01-22selftests/bpf: Add tests for program extensionsAlexei Starovoitov2-1/+64
Add program extension tests that build on top of fexit_bpf2bpf tests. Replace three global functions in previously loaded test_pkt_access.c program with three new implementations: int get_skb_len(struct __sk_buff *skb); int get_constant(long val); int get_skb_ifindex(int val, struct __sk_buff *skb, int var); New function return the same results as original only if arguments match. new_get_skb_ifindex() demonstrates that 'skb' argument doesn't have to be first and only argument of BPF program. All normal skb based accesses are available. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20200121005348.2769920-4-ast@kernel.org
2020-01-20selftests: Use consistent include paths for libbpfToke Høiland-Jørgensen115-164/+164
Fix all selftests to include libbpf header files with the bpf/ prefix, to be consistent with external users of the library. Also ensure that all includes of exported libbpf header files (those that are exported on 'make install' of the library) use bracketed includes instead of quoted. To not break the build, keep the old include path until everything has been changed to the new one; a subsequent patch will remove that. Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/157952560568.1683545.9649335788846513446.stgit@toke.dk
2020-01-15selftests/bpf: Add a test for attaching a bpf fentry/fexit trace to an XDP programEelco Chaudron1-0/+44
Add a test that will attach a FENTRY and FEXIT program to the XDP test program. It will also verify data from the XDP context on FENTRY and verifies the return code on exit. Signed-off-by: Eelco Chaudron <echaudro@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/157909410480.47481.11202505690938004673.stgit@xdp-tutorial
2020-01-15tools/bpf: Add self tests for bpf_send_signal_thread()Yonghong Song1-29/+22
The test_progs send_signal() is amended to test bpf_send_signal_thread() as well. $ ./test_progs -n 40 #40/1 send_signal_tracepoint:OK #40/2 send_signal_perf:OK #40/3 send_signal_nmi:OK #40/4 send_signal_tracepoint_thread:OK #40/5 send_signal_perf_thread:OK #40/6 send_signal_nmi_thread:OK #40 send_signal:OK Summary: 1/6 PASSED, 0 SKIPPED, 0 FAILED Also took this opportunity to rewrite the send_signal test using skeleton framework and array mmap to make code simpler and more readable. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200115035003.602425-1-yhs@fb.com
2020-01-10selftests/bpf: Add BPF_PROG, BPF_KPROBE, and BPF_KRETPROBE macrosAndrii Nakryiko9-60/+79
Streamline BPF_TRACE_x macro by moving out return type and section attribute definition out of macro itself. That makes those function look in source code similar to other BPF programs. Additionally, simplify its usage by determining number of arguments automatically (so just single BPF_TRACE vs a family of BPF_TRACE_1, BPF_TRACE_2, etc). Also, allow more natural function argument syntax without commas inbetween argument type and name. Given this helper is useful not only for tracing tp_btf/fenty/fexit programs, but could be used for LSM programs and others following the same pattern, rename BPF_TRACE macro into more generic BPF_PROG. Existing BPF_TRACE_x usages in selftests are converted to new BPF_PROG macro. Following the same pattern, define BPF_KPROBE and BPF_KRETPROBE macros for nicer usage of kprobe/kretprobe arguments, respectively. BPF_KRETPROBE, adopts same convention used by fexit programs, that last defined argument is probed function's return result. v4->v5: - fix test_overhead test (__set_task_comm is void) (Alexei); v3->v4: - rebased and fixed one more BPF_TRACE_x occurence (Alexei); v2->v3: - rename to shorter and as generic BPF_PROG (Alexei); v1->v2: - verified GCC handles pragmas as expected; - added descriptions to macros; - converted new STRUCT_OPS selftest to BPF_HANDLER (worked as expected); - added original context as 'ctx' parameter, for cases where it has to be passed into BPF helpers. This might cause an accidental naming collision, unfortunately, but at least it's easy to work around. Fortunately, this situation produces quite legible compilation error: progs/bpf_dctcp.c:46:6: error: redefinition of 'ctx' with a different type: 'int' vs 'unsigned long long *' int ctx = 123; ^ progs/bpf_dctcp.c:42:6: note: previous definition is here void BPF_HANDLER(dctcp_init, struct sock *sk) ^ ./bpf_trace_helpers.h:58:32: note: expanded from macro 'BPF_HANDLER' ____##name(unsigned long long *ctx, ##args) Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200110211634.1614739-1-andriin@fb.com
2020-01-10selftests/bpf: Add unit tests for global functionsAlexei Starovoitov7-0/+198
test_global_func[12] - check 512 stack limit. test_global_func[34] - check 8 frame call chain limit. test_global_func5 - check that non-ctx pointer cannot be passed into a function that expects context. test_global_func6 - check that ctx pointer is unmodified. test_global_func7 - check that global function returns scalar. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200110064124.1760511-7-ast@kernel.org
2020-01-10selftests/bpf: Modify a test to check global functionsAlexei Starovoitov1-2/+2
Make two static functions in test_xdp_noinline.c global: before: processed 2790 insns after: processed 2598 insns Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200110064124.1760511-6-ast@kernel.org
2020-01-10selftests/bpf: Add a test for a large global functionAlexei Starovoitov2-2/+12
test results: pyperf50 with always_inlined the same function five times: processed 46378 insns pyperf50 with global function: processed 6102 insns Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200110064124.1760511-5-ast@kernel.org
2020-01-10selftests/bpf: Add fexit-to-skb test for global funcsAlexei Starovoitov2-0/+43
Add simple fexit prog type to skb prog type test when subprogram is a global function. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200110064124.1760511-4-ast@kernel.org
2020-01-09bpf: Add bpf_dctcp exampleMartin KaFai Lau1-0/+210
This patch adds a bpf_dctcp example. It currently does not do no-ECN fallback but the same could be done through the cgrp2-bpf. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200109003517.3856825-1-kafai@fb.com
2019-12-18libbpf: Put Kconfig externs into .kconfig sectionAndrii Nakryiko2-12/+12
Move Kconfig-provided externs into custom .kconfig section. Add __kconfig into bpf_helpers.h for user convenience. Update selftests accordingly. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191219002837.3074619-2-andriin@fb.com
2019-12-18bpf: Allow to change skb mark in test_runNikita V. Shirokov1-0/+1
allow to pass skb's mark field into bpf_prog_test_run ctx for BPF_PROG_TYPE_SCHED_CLS prog type. that would allow to test bpf programs which are doing decision based on this field Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-12-15selftests/bpf: Add flexible array relocation testsAndrii Nakryiko5-4/+52
Add few tests validation CO-RE relocation handling of flexible array accesses. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191215070844.1014385-3-andriin@fb.com
2019-12-15selftests/bpf: Add tests for libbpf-provided externsAndrii Nakryiko2-0/+71
Add a set of tests validating libbpf-provided extern variables. One crucial feature that's tested is dead code elimination together with using invalid BPF helper. CONFIG_MISSING is not supposed to exist and should always be specified by libbpf as zero, which allows BPF verifier to correctly do branch pruning and not fail validation, when invalid BPF helper is called from dead if branch. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191214014710.3449601-5-andriin@fb.com
2019-12-15selftests/bpf: Add test validating data section to struct convertion layoutAndrii Nakryiko1-0/+37
Add a simple selftests validating datasection-to-struct layour dumping. Global variables are constructed in such a way as to cause both natural and artificial padding (through custom alignment requirement). Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-17-andriin@fb.com
2019-12-15selftests/bpf: Add BPF skeletons selftests and convert attach_probe.cAndrii Nakryiko1-22/+12
Add BPF skeleton generation to selftest/bpf's Makefile. Convert attach_probe.c to use skeleton. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-15-andriin@fb.com
2019-12-13selftests/bpf: Test wire_len/gso_segs in BPF_PROG_TEST_RUNStanislav Fomichev1-0/+5
Make sure we can pass arbitrary data in wire_len/gso_segs. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191213223028.161282-2-sdf@google.com
2019-12-13selftests/bpf: Let libbpf determine program type from section nameJakub Sitnicki1-1/+1
Now that libbpf can recognize SK_REUSEPORT programs, we no longer have to pass a prog_type hint before loading the object file. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191212102259.418536-3-jakub@cloudflare.com
2019-12-04selftests/bpf: Add a fexit/bpf2bpf test with target bpf prog no calleesYonghong Song2-2/+28
The existing fexit_bpf2bpf test covers the target progrm with callees. This patch added a test for the target program without callees. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191205010607.177904-1-yhs@fb.com
2019-12-04selftests/bpf: De-flake test_tcpbpfStanislav Fomichev1-0/+1
It looks like BPF program that handles BPF_SOCK_OPS_STATE_CB state can race with the bpf_map_lookup_elem("global_map"); I sometimes see the failures in this test and re-running helps. Since we know that we expect the callback to be called 3 times (one time for listener socket, two times for both ends of the connection), let's export this number and add simple retry logic around that. Also, let's make EXPECT_EQ() not return on failure, but continue evaluating all conditions; that should make potential debugging easier. With this fix in place I don't observe the flakiness anymore. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Lawrence Brakmo <brakmo@fb.com> Link: https://lore.kernel.org/bpf/20191204190955.170934-1-sdf@google.com
2019-11-27libbpf: Fix global variable relocationAndrii Nakryiko4-17/+17
Similarly to a0d7da26ce86 ("libbpf: Fix call relocation offset calculation bug"), relocations against global variables need to take into account referenced symbol's st_value, which holds offset into a corresponding data section (and, subsequently, offset into internal backing map). For static variables this offset is always zero and data offset is completely described by respective instruction's imm field. Convert a bunch of selftests to global variables. Previously they were relying on `static volatile` trick to ensure Clang doesn't inline static variables, which with global variables is not necessary anymore. Fixes: 393cdfbee809 ("libbpf: Support initialized global variables") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20191127200651.1381348-1-andriin@fb.com
2019-11-24bpf: Introduce BPF_TRACE_x helper for the tracing testsMartin KaFai Lau5-174/+67
For BPF_PROG_TYPE_TRACING, the bpf_prog's ctx is an array of u64. This patch borrows the idea from BPF_CALL_x in filter.h to convert a u64 to the arg type of the traced function. The new BPF_TRACE_x has an arg to specify the return type of a bpf_prog. It will be used in the future TCP-ops bpf_prog that may return "void". The new macros are defined in the new header file "bpf_trace_helpers.h". It is under selftests/bpf/ for now. It could be moved to libbpf later after seeing more upcoming non-tracing use cases. The tests are changed to use these new macros also. Hence, the k[s]u8/16/32/64 are no longer needed and they are removed from the bpf_helpers.h. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191123202504.1502696-1-kafai@fb.com
2019-11-24bpf, testing: Add various tail call test casesDaniel Borkmann5-0/+211
Add several BPF kselftest cases for tail calls which test the various patch directions, and that multiple locations are patched in same and different programs. # ./test_progs -n 45 #45/1 tailcall_1:OK #45/2 tailcall_2:OK #45/3 tailcall_3:OK #45/4 tailcall_4:OK #45/5 tailcall_5:OK #45 tailcalls:OK Summary: 1/5 PASSED, 0 SKIPPED, 0 FAILED I've also verified the JITed dump after each of the rewrite cases that it matches expectations. Also regular test_verifier suite passes fine which contains further tail call tests: # ./test_verifier [...] Summary: 1563 PASSED, 0 SKIPPED, 0 FAILED Checked under JIT, interpreter and JIT + hardening. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/3d6cbecbeb171117dccfe153306e479798fb608d.1574452833.git.daniel@iogearbox.net
2019-11-24selftests/bpf: Add BPF trampoline performance testAlexei Starovoitov1-0/+43
Add a test that benchmarks different ways of attaching BPF program to a kernel function. Here are the results for 2.4Ghz x86 cpu on a kernel without mitigations: $ ./test_progs -n 49 -v|grep events task_rename base 2743K events per sec task_rename kprobe 2419K events per sec task_rename kretprobe 1876K events per sec task_rename raw_tp 2578K events per sec task_rename fentry 2710K events per sec task_rename fexit 2685K events per sec On a kernel with retpoline: $ ./test_progs -n 49 -v|grep events task_rename base 2401K events per sec task_rename kprobe 1930K events per sec task_rename kretprobe 1485K events per sec task_rename raw_tp 2053K events per sec task_rename fentry 2351K events per sec task_rename fexit 2185K events per sec All 5 approaches: - kprobe/kretprobe in __set_task_comm() - raw tracepoint in trace_task_rename() - fentry/fexit in __set_task_comm() are roughly equivalent. __set_task_comm() by itself is quite fast, so any extra instructions add up. Until BPF trampoline was introduced the fastest mechanism was raw tracepoint. kprobe via ftrace was second best. kretprobe is slow due to trap. New fentry/fexit methods via BPF trampoline are clearly the fastest and the difference is more pronounced with retpoline on, since BPF trampoline doesn't use indirect jumps. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20191122011515.255371-1-ast@kernel.org
2019-11-24selftests/bpf: Ensure core_reloc_kernel is reading test_progs's data onlyAndrii Nakryiko1-0/+4
test_core_reloc_kernel.c selftest is the only CO-RE test that reads and returns for validation calling thread's information (pid, tgid, comm). Thus it has to make sure that only test_prog's invocations are honored. Fixes: df36e621418b ("selftests/bpf: add CO-RE relocs testing setup") Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20191121175900.3486133-1-andriin@fb.com
2019-11-24libbpf: Support initialized global variablesAndrii Nakryiko13-26/+26
Initialized global variables are no different in ELF from static variables, and don't require any extra support from libbpf. But they are matching semantics of global data (backed by BPF maps) more closely, preventing LLVM/Clang from aggressively inlining constant values and not requiring volatile incantations to prevent those. This patch enables global variables. It still disables uninitialized variables, which will be put into special COM (common) ELF section, because BPF doesn't allow uninitialized data to be accessed. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191121070743.1309473-5-andriin@fb.com
2019-11-19libbpf: Fix call relocation offset calculation bugAndrii Nakryiko3-6/+6
When relocating subprogram call, libbpf doesn't take into account relo->text_off, which comes from symbol's value. This generally works fine for subprograms implemented as static functions, but breaks for global functions. Taking a simplified test_pkt_access.c as an example: __attribute__ ((noinline)) static int test_pkt_access_subprog1(volatile struct __sk_buff *skb) { return skb->len * 2; } __attribute__ ((noinline)) static int test_pkt_access_subprog2(int val, volatile struct __sk_buff *skb) { return skb->len + val; } SEC("classifier/test_pkt_access") int test_pkt_access(struct __sk_buff *skb) { if (test_pkt_access_subprog1(skb) != skb->len * 2) return TC_ACT_SHOT; if (test_pkt_access_subprog2(2, skb) != skb->len + 2) return TC_ACT_SHOT; return TC_ACT_UNSPEC; } When compiled, we get two relocations, pointing to '.text' symbol. .text has st_value set to 0 (it points to the beginning of .text section): 0000000000000008 000000050000000a R_BPF_64_32 0000000000000000 .text 0000000000000040 000000050000000a R_BPF_64_32 0000000000000000 .text test_pkt_access_subprog1 and test_pkt_access_subprog2 offsets (targets of two calls) are encoded within call instruction's imm32 part as -1 and 2, respectively: 0000000000000000 test_pkt_access_subprog1: 0: 61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0) 1: 64 00 00 00 01 00 00 00 w0 <<= 1 2: 95 00 00 00 00 00 00 00 exit 0000000000000018 test_pkt_access_subprog2: 3: 61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0) 4: 04 00 00 00 02 00 00 00 w0 += 2 5: 95 00 00 00 00 00 00 00 exit 0000000000000000 test_pkt_access: 0: bf 16 00 00 00 00 00 00 r6 = r1 ===> 1: 85 10 00 00 ff ff ff ff call -1 2: bc 01 00 00 00 00 00 00 w1 = w0 3: b4 00 00 00 02 00 00 00 w0 = 2 4: 61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0) 5: 64 02 00 00 01 00 00 00 w2 <<= 1 6: 5e 21 08 00 00 00 00 00 if w1 != w2 goto +8 <LBB0_3> 7: bf 61 00 00 00 00 00 00 r1 = r6 ===> 8: 85 10 00 00 02 00 00 00 call 2 9: bc 01 00 00 00 00 00 00 w1 = w0 10: 61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0) 11: 04 02 00 00 02 00 00 00 w2 += 2 12: b4 00 00 00 ff ff ff ff w0 = -1 13: 1e 21 01 00 00 00 00 00 if w1 == w2 goto +1 <LBB0_3> 14: b4 00 00 00 02 00 00 00 w0 = 2 0000000000000078 LBB0_3: 15: 95 00 00 00 00 00 00 00 exit Now, if we compile example with global functions, the setup changes. Relocations are now against specifically test_pkt_access_subprog1 and test_pkt_access_subprog2 symbols, with test_pkt_access_subprog2 pointing 24 bytes into its respective section (.text), i.e., 3 instructions in: 0000000000000008 000000070000000a R_BPF_64_32 0000000000000000 test_pkt_access_subprog1 0000000000000048 000000080000000a R_BPF_64_32 0000000000000018 test_pkt_access_subprog2 Calls instructions now encode offsets relative to function symbols and are both set ot -1: 0000000000000000 test_pkt_access_subprog1: 0: 61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0) 1: 64 00 00 00 01 00 00 00 w0 <<= 1 2: 95 00 00 00 00 00 00 00 exit 0000000000000018 test_pkt_access_subprog2: 3: 61 20 00 00 00 00 00 00 r0 = *(u32 *)(r2 + 0) 4: 0c 10 00 00 00 00 00 00 w0 += w1 5: 95 00 00 00 00 00 00 00 exit 0000000000000000 test_pkt_access: 0: bf 16 00 00 00 00 00 00 r6 = r1 ===> 1: 85 10 00 00 ff ff ff ff call -1 2: bc 01 00 00 00 00 00 00 w1 = w0 3: b4 00 00 00 02 00 00 00 w0 = 2 4: 61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0) 5: 64 02 00 00 01 00 00 00 w2 <<= 1 6: 5e 21 09 00 00 00 00 00 if w1 != w2 goto +9 <LBB2_3> 7: b4 01 00 00 02 00 00 00 w1 = 2 8: bf 62 00 00 00 00 00 00 r2 = r6 ===> 9: 85 10 00 00 ff ff ff ff call -1 10: bc 01 00 00 00 00 00 00 w1 = w0 11: 61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0) 12: 04 02 00 00 02 00 00 00 w2 += 2 13: b4 00 00 00 ff ff ff ff w0 = -1 14: 1e 21 01 00 00 00 00 00 if w1 == w2 goto +1 <LBB2_3> 15: b4 00 00 00 02 00 00 00 w0 = 2 0000000000000080 LBB2_3: 16: 95 00 00 00 00 00 00 00 exit Thus the right formula to calculate target call offset after relocation should take into account relocation's target symbol value (offset within section), call instruction's imm32 offset, and (subtracting, to get relative instruction offset) instruction index of call instruction itself. All that is shifted by number of instructions in main program, given all sub-programs are copied over after main program. Convert few selftests relying on bpf-to-bpf calls to use global functions instead of static ones. Fixes: 48cca7e44f9f ("libbpf: add support for bpf_call") Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191119224447.3781271-1-andriin@fb.com
2019-11-18selftests, bpf: Workaround an alu32 sub-register spilling issueYonghong Song1-1/+3
Currently, with latest llvm trunk, selftest test_progs failed obj file test_seg6_loop.o with the following error in verifier: infinite loop detected at insn 76 The byte code sequence looks like below, and noted that alu32 has been turned off by default for better generated codes in general: 48: w3 = 100 49: *(u32 *)(r10 - 68) = r3 ... ; if (tlv.type == SR6_TLV_PADDING) { 76: if w3 == 5 goto -18 <LBB0_19> ... 85: r1 = *(u32 *)(r10 - 68) ; for (int i = 0; i < 100; i++) { 86: w1 += -1 87: if w1 == 0 goto +5 <LBB0_20> 88: *(u32 *)(r10 - 68) = r1 The main reason for verification failure is due to partial spills at r10 - 68 for induction variable "i". Current verifier only handles spills with 8-byte values. The above 4-byte value spill to stack is treated to STACK_MISC and its content is not saved. For the above example: w3 = 100 R3_w=inv100 fp-64_w=inv1086626730498 *(u32 *)(r10 - 68) = r3 R3_w=inv100 fp-64_w=inv1086626730498 ... r1 = *(u32 *)(r10 - 68) R1_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) fp-64=inv1086626730498 To resolve this issue, verifier needs to be extended to track sub-registers in spilling, or llvm needs to enhanced to prevent sub-register spilling in register allocation phase. The former will increase verifier complexity and the latter will need some llvm "hacking". Let us workaround this issue by declaring the induction variable as "long" type so spilling will happen at non sub-register level. We can revisit this later if sub-register spilling causes similar or other verification issues. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20191117214036.1309510-1-yhs@fb.com
2019-11-18selftests/bpf: Add BPF_TYPE_MAP_ARRAY mmap() testsAndrii Nakryiko1-0/+45
Add selftests validating mmap()-ing BPF array maps: both single-element and multi-element ones. Check that plain bpf_map_update_elem() and bpf_map_lookup_elem() work correctly with memory-mapped array. Also convert CO-RE relocation tests to use memory-mapped views of global data. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20191117172806.2195367-6-andriin@fb.com
2019-11-15selftests/bpf: Add a test for attaching BPF prog to another BPF prog and subprogAlexei Starovoitov1-0/+91
Add a test that attaches one FEXIT program to main sched_cls networking program and two other FEXIT programs to subprograms. All three tracing programs access return values and skb->len of networking program and subprograms. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20191114185720.1641606-21-ast@kernel.org
2019-11-15selftests/bpf: Extend test_pkt_access testAlexei Starovoitov1-2/+36
The test_pkt_access.o is used by multiple tests. Fix its section name so that program type can be automatically detected by libbpf and make it call other subprograms with skb argument. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20191114185720.1641606-20-ast@kernel.org
2019-11-15selftests/bpf: Add fexit tests for BPF trampolineAlexei Starovoitov1-0/+98
Add fexit tests for BPF trampoline that checks kernel functions with up to 6 arguments of different sizes and their return values. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20191114185720.1641606-11-ast@kernel.org
2019-11-15selftests/bpf: Add test for BPF trampolineAlexei Starovoitov1-0/+90
Add sanity test for BPF trampoline that checks kernel functions with up to 6 arguments of different sizes. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20191114185720.1641606-10-ast@kernel.org
2019-11-15selftest/bpf: Simple test for fentry/fexitAlexei Starovoitov1-0/+52
Add simple test for fentry and fexit programs around eth_type_trans. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20191114185720.1641606-8-ast@kernel.org
2019-11-11bpf, testing: Workaround a verifier failure for test_progsYonghong Song1-1/+4
With latest llvm compiler, running test_progs will have the following verifier failure for test_sysctl_loop1.o: libbpf: load bpf program failed: Permission denied libbpf: -- BEGIN DUMP LOG --- libbpf: invalid indirect read from stack var_off (0x0; 0xff)+196 size 7 ... libbpf: -- END LOG -- libbpf: failed to load program 'cgroup/sysctl' libbpf: failed to load object 'test_sysctl_loop1.o' The related bytecode looks as below: 0000000000000308 LBB0_8: 97: r4 = r10 98: r4 += -288 99: r4 += r7 100: w8 &= 255 101: r1 = r10 102: r1 += -488 103: r1 += r8 104: r2 = 7 105: r3 = 0 106: call 106 107: w1 = w0 108: w1 += -1 109: if w1 > 6 goto -24 <LBB0_5> 110: w0 += w8 111: r7 += 8 112: w8 = w0 113: if r7 != 224 goto -17 <LBB0_8> And source code: for (i = 0; i < ARRAY_SIZE(tcp_mem); ++i) { ret = bpf_strtoul(value + off, MAX_ULONG_STR_LEN, 0, tcp_mem + i); if (ret <= 0 || ret > MAX_ULONG_STR_LEN) return 0; off += ret & MAX_ULONG_STR_LEN; } Current verifier is not able to conclude that register w0 before '+' at insn 110 has a range of 1 to 7 and thinks it is from 0 - 255. This leads to more conservative range for w8 at insn 112, and later verifier complaint. Let us workaround this issue until we found a compiler and/or verifier solution. The workaround in this patch is to make variable 'ret' volatile, which will force a reload and then '&' operation to ensure better value range. With this patch, I got the below byte code for the loop: 0000000000000328 LBB0_9: 101: r4 = r10 102: r4 += -288 103: r4 += r7 104: w8 &= 255 105: r1 = r10 106: r1 += -488 107: r1 += r8 108: r2 = 7 109: r3 = 0 110: call 106 111: *(u32 *)(r10 - 64) = r0 112: r1 = *(u32 *)(r10 - 64) 113: if w1 s< 1 goto -28 <LBB0_5> 114: r1 = *(u32 *)(r10 - 64) 115: if w1 s> 7 goto -30 <LBB0_5> 116: r1 = *(u32 *)(r10 - 64) 117: w1 &= 7 118: w1 += w8 119: r7 += 8 120: w8 = w1 121: if r7 != 224 goto -21 <LBB0_9> Insn 117 did the '&' operation and we got more precise value range for 'w8' at insn 120. The test is happy then: #3/17 test_sysctl_loop1.o:OK Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20191107170045.2503480-1-yhs@fb.com
2019-11-10selftests/bpf: Add tests for automatic map unpinning on load failureToke Høiland-Jørgensen1-1/+1
This add tests for the different variations of automatic map unpinning on load failure. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/157333184838.88376.8243704248624814775.stgit@toke.dk
2019-11-07bpf: Add cb access in kfree_skb testMartin KaFai Lau1-5/+20
Access the skb->cb[] in the kfree_skb test. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191107180905.4097871-1-kafai@fb.com
2019-11-06libbpf: Simplify BPF_CORE_READ_BITFIELD_PROBED usageAndrii Nakryiko1-12/+7
Streamline BPF_CORE_READ_BITFIELD_PROBED interface to follow BPF_CORE_READ_BITFIELD (direct) and BPF_CORE_READ, in general, i.e., just return read result or 0, if underlying bpf_probe_read() failed. In practice, real applications rarely check bpf_probe_read() result, because it has to always work or otherwise it's a bug. So propagating internal bpf_probe_read() error from this macro hurts usability without providing real benefits in practice. This patch fixes the issue and simplifies usage, noticeable even in selftest itself. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20191106201500.2582438-1-andriin@fb.com
2019-11-04selftests/bpf: Add field size relocation testsAndrii Nakryiko4-0/+88
Add test verifying correctness and logic of field size relocation support in libbpf. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191101222810.1246166-6-andriin@fb.com
2019-11-04selftest/bpf: Add relocatable bitfield reading testsAndrii Nakryiko8-0/+212
Add a bunch of selftests verifying correctness of relocatable bitfield reading support in libbpf. Both bpf_probe_read()-based and direct read-based bitfield macros are tested. core_reloc.c "test_harness" is extended to support raw tracepoint and new typed raw tracepoints as test BPF program types. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191101222810.1246166-5-andriin@fb.com
2019-11-04selftests/bpf: Remove too strict field offset relo test casesAndrii Nakryiko9-90/+4
As libbpf is going to gain support for more field relocations, including field size, some restrictions about exact size match are going to be lifted. Remove test cases that explicitly test such failures. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191101222810.1246166-2-andriin@fb.com
2019-11-02bpf, testing: Add selftest to read/write sockaddr from user spaceDaniel Borkmann1-0/+26
Tested on x86-64 and Ilya was also kind enough to give it a spin on s390x, both passing with probe_user:OK there. The test is using the newly added bpf_probe_read_user() to dump sockaddr from connect call into .bss BPF map and overrides the user buffer via bpf_probe_write_user(): # ./test_progs [...] #17 pkt_md_access:OK #18 probe_user:OK #19 prog_run_xattr:OK [...] Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/90f449d8af25354e05080e82fc6e2d3179da30ea.1572649915.git.daniel@iogearbox.net
2019-11-02bpf, testing: Convert prog tests to probe_read_{user, kernel}{, _str} helperDaniel Borkmann4-52/+57
Use probe read *_{kernel,user}{,_str}() helpers instead of bpf_probe_read() or bpf_probe_read_user_str() for program tests where appropriate. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/4a61d4b71ce3765587d8ef5cb93afa18515e5b3e.1572649915.git.daniel@iogearbox.net
2019-11-02selftests: Add tests for automatic map pinningToke Høiland-Jørgensen2-0/+47
This adds a new BPF selftest to exercise the new automatic map pinning code. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/157269298209.394725.15420085139296213182.stgit@toke.dk
2019-10-21selftests/bpf: Make reference_tracking test use subtestsAndrii Nakryiko1-9/+9
reference_tracking is actually a set of 9 sub-tests. Make it explicitly so. Also, add explicit "classifier/" prefix to BPF program section names to let libbpf correctly guess program type. Thus, also remove explicit bpf_prog__set_type() call. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191021033902.3856966-7-andriin@fb.com
2019-10-17selftests/bpf: Move test_queue_stack_map.h into progs/ where it belongsAndrii Nakryiko1-0/+59
test_queue_stack_map.h is used only from BPF programs. Thus it should be part of progs/ subdir. An added benefit of moving it there is that new TEST_RUNNER_DEFINE_RULES macro-rule will properly capture dependency on this header for all BPF objects and trigger re-build, if it changes. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191016060051.2024182-7-andriin@fb.com
2019-10-17selftests/bpf: Make CO-RE reloc test impartial to test_progs flavorAndrii Nakryiko2-2/+3
test_core_reloc_kernel test captures its own process name and validates it as part of the test. Given extra "flavors" of test_progs, this break for anything by default test_progs binary. Fix the test to cut out flavor part of the process name. Fixes: ee2eb063d330 ("selftests/bpf: Add BPF_CORE_READ and BPF_CORE_READ_STR_INTO macro tests") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191016060051.2024182-3-andriin@fb.com