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2020-07-25selftests/bpf: Add test for bpf array map iteratorsYonghong Song2-0/+86
Two subtests are added. $ ./test_progs -n 4 ... #4/20 bpf_array_map:OK #4/21 bpf_percpu_array_map:OK ... The bpf_array_map subtest also tested bpf program changing array element values and send key/value to user space through bpf_seq_write() interface. Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-25selftests/bpf: Add test for bpf hash map iteratorsYonghong Song2-0/+150
Two subtests are added. $ ./test_progs -n 4 ... #4/18 bpf_hash_map:OK #4/19 bpf_percpu_hash_map:OK ... Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-21samples/bpf, selftests/bpf: Use bpf_probe_read_kernelIlya Leoshkevich5-7/+7
A handful of samples and selftests fail to build on s390, because after commit 0ebeea8ca8a4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work") bpf_probe_read is not available anymore. Fix by using bpf_probe_read_kernel. Signed-off-by: Ilya Leoshkevich <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-17selftests/bpf: Tests for BPF_SK_LOOKUP attach pointJakub Sitnicki1-0/+641
Add tests to test_progs that exercise: - attaching/detaching/querying programs to BPF_SK_LOOKUP hook, - redirecting socket lookup to a socket selected by BPF program, - failing a socket lookup on BPF program's request, - error scenarios for selecting a socket from BPF program, - accessing BPF program context, - attaching and running multiple BPF programs. Run log: bash-5.0# ./test_progs -n 70 #70/1 query lookup prog:OK #70/2 TCP IPv4 redir port:OK #70/3 TCP IPv4 redir addr:OK #70/4 TCP IPv4 redir with reuseport:OK #70/5 TCP IPv4 redir skip reuseport:OK #70/6 TCP IPv6 redir port:OK #70/7 TCP IPv6 redir addr:OK #70/8 TCP IPv4->IPv6 redir port:OK #70/9 TCP IPv6 redir with reuseport:OK #70/10 TCP IPv6 redir skip reuseport:OK #70/11 UDP IPv4 redir port:OK #70/12 UDP IPv4 redir addr:OK #70/13 UDP IPv4 redir with reuseport:OK #70/14 UDP IPv4 redir skip reuseport:OK #70/15 UDP IPv6 redir port:OK #70/16 UDP IPv6 redir addr:OK #70/17 UDP IPv4->IPv6 redir port:OK #70/18 UDP IPv6 redir and reuseport:OK #70/19 UDP IPv6 redir skip reuseport:OK #70/20 TCP IPv4 drop on lookup:OK #70/21 TCP IPv6 drop on lookup:OK #70/22 UDP IPv4 drop on lookup:OK #70/23 UDP IPv6 drop on lookup:OK #70/24 TCP IPv4 drop on reuseport:OK #70/25 TCP IPv6 drop on reuseport:OK #70/26 UDP IPv4 drop on reuseport:OK #70/27 TCP IPv6 drop on reuseport:OK #70/28 sk_assign returns EEXIST:OK #70/29 sk_assign honors F_REPLACE:OK #70/30 sk_assign accepts NULL socket:OK #70/31 access ctx->sk:OK #70/32 narrow access to ctx v4:OK #70/33 narrow access to ctx v6:OK #70/34 sk_assign rejects TCP established:OK #70/35 sk_assign rejects UDP connected:OK #70/36 multi prog - pass, pass:OK #70/37 multi prog - drop, drop:OK #70/38 multi prog - pass, drop:OK #70/39 multi prog - drop, pass:OK #70/40 multi prog - pass, redir:OK #70/41 multi prog - redir, pass:OK #70/42 multi prog - drop, redir:OK #70/43 multi prog - redir, drop:OK #70/44 multi prog - redir, redir:OK #70 sk_lookup:OK Summary: 1/44 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Jakub Sitnicki <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-16selftest: Add tests for XDP programs in CPUMAP entriesLorenzo Bianconi1-0/+36
Similar to what have been done for DEVMAP, introduce tests to verify ability to add a XDP program to an entry in a CPUMAP. Verify CPUMAP programs can not be attached to devices as a normal XDP program, and only programs with BPF_XDP_CPUMAP attach type can be loaded in a CPUMAP. Signed-off-by: Lorenzo Bianconi <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/9c632fcea5382ea7b4578bd06b6eddf382c3550b.1594734381.git.lorenzo@kernel.org
2020-07-13selftests/bpf: Fix merge conflict resolutionAlexei Starovoitov1-14/+0
Remove double definition of structs. Fixes: 71930d61025e ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net") Signed-off-by: Alexei Starovoitov <[email protected]>
2020-07-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller6-4/+149
Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-07-13 The following pull-request contains BPF updates for your *net-next* tree. We've added 36 non-merge commits during the last 7 day(s) which contain a total of 62 files changed, 2242 insertions(+), 468 deletions(-). The main changes are: 1) Avoid trace_printk warning banner by switching bpf_trace_printk to use its own tracing event, from Alan. 2) Better libbpf support on older kernels, from Andrii. 3) Additional AF_XDP stats, from Ciara. 4) build time resolution of BTF IDs, from Jiri. 5) BPF_CGROUP_INET_SOCK_RELEASE hook, from Stanislav. ==================== Signed-off-by: David S. Miller <[email protected]>
2020-07-13tools/bpftool: Strip away modifiers from global variablesAndrii Nakryiko1-2/+4
Reliably remove all the type modifiers from read-only (.rodata) global variable definitions, including cases of inner field const modifiers and arrays of const values. Also modify one of selftests to ensure that const volatile struct doesn't prevent user-space from modifying .rodata variable. Fixes: 985ead416df3 ("bpftool: Add skeleton codegen command") Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-13selftests/bpf: Add selftests verifying bpf_trace_printk() behaviourAlan Maguire1-0/+21
Simple selftests that verifies bpf_trace_printk() returns a sensible value and tracing messages appear. Signed-off-by: Alan Maguire <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-13selftests/bpf: Add test for resolve_btfidsJiri Olsa1-0/+50
Adding resolve_btfids test under test_progs suite. It's possible to use btf_ids.h header and its logic in user space application, so we can add easy test for it. The test defines BTF_ID_LIST and checks it gets properly resolved. For this reason the test_progs binary (and other binaries that use TRUNNER* macros) is processed with resolve_btfids tool, which resolves BTF IDs in .BTF_ids section. The BTF data are taken from btf_data.o object rceated from progs/btf_data.c. Signed-off-by: Jiri Olsa <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Tested-by: Andrii Nakryiko <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller5-3/+67
All conflicts seemed rather trivial, with some guidance from Saeed Mameed on the tc_ct.c one. Signed-off-by: David S. Miller <[email protected]>
2020-07-09selftests/bpf: Switch perf_buffer test to tracepoint and skeletonAndrii Nakryiko1-2/+2
Switch perf_buffer test to use skeleton to avoid use of bpf_prog_load() and make test a bit more succinct. Also switch BPF program to use tracepoint instead of kprobe, as that allows to support older kernels, which had tracepoint support before kprobe support in the form that libbpf expects (i.e., libbpf expects /sys/bus/event_source/devices/kprobe/type, which doesn't always exist on old kernels). Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-09selftests/bpf: Add test relying only on CO-RE and no recent kernel featuresAndrii Nakryiko1-0/+30
Add a test that relies on CO-RE, but doesn't expect any of the recent features, not available on old kernels. This is useful for Travis CI tests running against very old kernels (e.g., libbpf has 4.9 kernel testing now), to verify that CO-RE still works, even if kernel itself doesn't support BTF yet, as long as there is .BTF embedded into vmlinux image by pahole. Given most of CO-RE doesn't require any kernel awareness of BTF, it is a useful test to validate that libbpf's BTF sanitization is working well even with ancient kernels. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-08selftests/bpf: Test BPF_CGROUP_INET_SOCK_RELEASEStanislav Fomichev1-0/+42
Simple test that enforces a single SOCK_DGRAM socket per cgroup. Signed-off-by: Stanislav Fomichev <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller23-154/+1802
Daniel Borkmann says: ==================== pull-request: bpf-next 2020-07-04 The following pull-request contains BPF updates for your *net-next* tree. We've added 73 non-merge commits during the last 17 day(s) which contain a total of 106 files changed, 5233 insertions(+), 1283 deletions(-). The main changes are: 1) bpftool ability to show PIDs of processes having open file descriptors for BPF map/program/link/BTF objects, relying on BPF iterator progs to extract this info efficiently, from Andrii Nakryiko. 2) Addition of BPF iterator progs for dumping TCP and UDP sockets to seq_files, from Yonghong Song. 3) Support access to BPF map fields in struct bpf_map from programs through BTF struct access, from Andrey Ignatov. 4) Add a bpf_get_task_stack() helper to be able to dump /proc/*/stack via seq_file from BPF iterator progs, from Song Liu. 5) Make SO_KEEPALIVE and related options available to bpf_setsockopt() helper, from Dmitry Yakunin. 6) Optimize BPF sk_storage selection of its caching index, from Martin KaFai Lau. 7) Removal of redundant synchronize_rcu()s from BPF map destruction which has been a historic leftover, from Alexei Starovoitov. 8) Several improvements to test_progs to make it easier to create a shell loop that invokes each test individually which is useful for some CIs, from Jesper Dangaard Brouer. 9) Fix bpftool prog dump segfault when compiled without skeleton code on older clang versions, from John Fastabend. 10) Bunch of cleanups and minor improvements, from various others. ==================== Signed-off-by: David S. Miller <[email protected]>
2020-07-03selftests/bpf: Fix compilation error of bpf_iter_task_stack.cSong Liu1-1/+1
BPF selftests show a compilation error as follows: libbpf: invalid relo for 'entries' in special section 0xfff2; forgot to initialize global var?.. Fix it by initializing 'entries' to zeros. Fixes: c7568114bc56 ("selftests/bpf: Add bpf_iter test with bpf_get_task_stack()") Reported-by: Jesper Dangaard Brouer <[email protected]> Signed-off-by: Song Liu <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-01selftests/bpf: Switch test_vmlinux to use hrtimer_range_start_ns.Hao Luo1-8/+8
The test_vmlinux test uses hrtimer_nanosleep as hook to test tracing programs. But in a kernel built by clang, which performs more aggresive inlining, that function gets inlined into its caller SyS_nanosleep. Therefore, even though fentry and kprobe do hook on the function, they aren't triggered by the call to nanosleep in the test. A possible fix is switching to use a function that is less likely to be inlined, such as hrtimer_range_start_ns. The EXPORT_SYMBOL functions shouldn't be inlined based on the description of [1], therefore safe to use for this test. Also the arguments of this function include the duration of sleep, therefore suitable for test verification. [1] af3b56289be1 time: don't inline EXPORT_SYMBOL functions Tested: In a clang build kernel, before this change, the test fails: test_vmlinux:PASS:skel_open 0 nsec test_vmlinux:PASS:skel_attach 0 nsec test_vmlinux:PASS:tp 0 nsec test_vmlinux:PASS:raw_tp 0 nsec test_vmlinux:PASS:tp_btf 0 nsec test_vmlinux:FAIL:kprobe not called test_vmlinux:FAIL:fentry not called After switching to hrtimer_range_start_ns, the test passes: test_vmlinux:PASS:skel_open 0 nsec test_vmlinux:PASS:skel_attach 0 nsec test_vmlinux:PASS:tp 0 nsec test_vmlinux:PASS:raw_tp 0 nsec test_vmlinux:PASS:tp_btf 0 nsec test_vmlinux:PASS:kprobe 0 nsec test_vmlinux:PASS:fentry 0 nsec Signed-off-by: Hao Luo <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-01selftests/bpf: Add bpf_iter test with bpf_get_task_stack()Song Liu1-0/+37
The new test is similar to other bpf_iter tests. It dumps all /proc/<pid>/stack to a seq_file. Here is some example output: pid: 2873 num_entries: 3 [<0>] worker_thread+0xc6/0x380 [<0>] kthread+0x135/0x150 [<0>] ret_from_fork+0x22/0x30 pid: 2874 num_entries: 9 [<0>] __bpf_get_stack+0x15e/0x250 [<0>] bpf_prog_22a400774977bb30_dump_task_stack+0x4a/0xb3c [<0>] bpf_iter_run_prog+0x81/0x170 [<0>] __task_seq_show+0x58/0x80 [<0>] bpf_seq_read+0x1c3/0x3b0 [<0>] vfs_read+0x9e/0x170 [<0>] ksys_read+0xa7/0xe0 [<0>] do_syscall_64+0x4c/0xa0 [<0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Note: bpf_iter test as-is doesn't print the contents of the seq_file. To see the example above, it is necessary to add printf() to do_dummy_read. Signed-off-by: Song Liu <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-07-01selftests/bpf: Add byte swapping selftestAndrii Nakryiko1-0/+37
Add simple selftest validating byte swap built-ins and compile-time macros. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller5-3/+53
Daniel Borkmann says: ==================== pull-request: bpf 2020-06-30 The following pull-request contains BPF updates for your *net* tree. We've added 28 non-merge commits during the last 9 day(s) which contain a total of 35 files changed, 486 insertions(+), 232 deletions(-). The main changes are: 1) Fix an incorrect verifier branch elimination for PTR_TO_BTF_ID pointer types, from Yonghong Song. 2) Fix UAPI for sockmap and flow_dissector progs that were ignoring various arguments passed to BPF_PROG_{ATTACH,DETACH}, from Lorenz Bauer & Jakub Sitnicki. 3) Fix broken AF_XDP DMA hacks that are poking into dma-direct and swiotlb internals and integrate it properly into DMA core, from Christoph Hellwig. 4) Fix RCU splat from recent changes to avoid skipping ingress policy when kTLS is enabled, from John Fastabend. 5) Fix BPF ringbuf map to enforce size to be the power of 2 in order for its position masking to work, from Andrii Nakryiko. 6) Fix regression from CAP_BPF work to re-allow CAP_SYS_ADMIN for loading of network programs, from Maciej Żenczykowski. 7) Fix libbpf section name prefix for devmap progs, from Jesper Dangaard Brouer. 8) Fix formatting in UAPI documentation for BPF helpers, from Quentin Monnet. ==================== Signed-off-by: David S. Miller <[email protected]>
2020-06-30bpf: Add tests for PTR_TO_BTF_ID vs. null comparisonYonghong Song2-0/+44
Add two tests for PTR_TO_BTF_ID vs. null ptr comparison, one for PTR_TO_BTF_ID in the ctx structure and the other for PTR_TO_BTF_ID after one level pointer chasing. In both cases, the test ensures condition is not removed. For example, for this test struct bpf_fentry_test_t { struct bpf_fentry_test_t *a; }; int BPF_PROG(test7, struct bpf_fentry_test_t *arg) { if (arg == 0) test7_result = 1; return 0; } Before the previous verifier change, we have xlated codes: int test7(long long unsigned int * ctx): ; int BPF_PROG(test7, struct bpf_fentry_test_t *arg) 0: (79) r1 = *(u64 *)(r1 +0) ; int BPF_PROG(test7, struct bpf_fentry_test_t *arg) 1: (b4) w0 = 0 2: (95) exit After the previous verifier change, we have: int test7(long long unsigned int * ctx): ; int BPF_PROG(test7, struct bpf_fentry_test_t *arg) 0: (79) r1 = *(u64 *)(r1 +0) ; if (arg == 0) 1: (55) if r1 != 0x0 goto pc+4 ; test7_result = 1; 2: (18) r1 = map[id:6][0]+48 4: (b7) r2 = 1 5: (7b) *(u64 *)(r1 +0) = r2 ; int BPF_PROG(test7, struct bpf_fentry_test_t *arg) 6: (b4) w0 = 0 7: (95) exit Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: John Fastabend <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-28selftests/bpf: Test auto-load disabling logic for BPF programsAndrii Nakryiko1-0/+40
Validate that BPF object with broken (in multiple ways) BPF program can still be successfully loaded, if that broken BPF program is disabled. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-28bpf, sockmap: Add ingres skb tests that utilize merge skbsJohn Fastabend1-1/+7
Add a test to check strparser merging skbs is working. Signed-off-by: John Fastabend <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Link: https://lore.kernel.org/bpf/159312681884.18340.4922800172600252370.stgit@john-XPS-13-9370
2020-06-25bpf: tcp: bpf_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTTNeal Cardwell1-3/+2
Apply the fix from: "tcp_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT" to the BPF implementation of TCP CUBIC congestion control. Repeating the commit description here for completeness: Mirja Kuehlewind reported a bug in Linux TCP CUBIC Hystart, where Hystart HYSTART_DELAY mechanism can exit Slow Start spuriously on an ACK when the minimum rtt of a connection goes down. From inspection it is clear from the existing code that this could happen in an example like the following: o The first 8 RTT samples in a round trip are 150ms, resulting in a curr_rtt of 150ms and a delay_min of 150ms. o The 9th RTT sample is 100ms. The curr_rtt does not change after the first 8 samples, so curr_rtt remains 150ms. But delay_min can be lowered at any time, so delay_min falls to 100ms. The code executes the HYSTART_DELAY comparison between curr_rtt of 150ms and delay_min of 100ms, and the curr_rtt is declared far enough above delay_min to force a (spurious) exit of Slow start. The fix here is simple: allow every RTT sample in a round trip to lower the curr_rtt. Fixes: 6de4a9c430b5 ("bpf: tcp: Add bpf_cubic example") Reported-by: Mirja Kuehlewind <[email protected]> Signed-off-by: Neal Cardwell <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Acked-by: Soheil Hassas Yeganeh <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-06-25libbpf: Adjust SEC short cut for expected attach type BPF_XDP_DEVMAPJesper Dangaard Brouer1-1/+1
Adjust the SEC("xdp_devmap/") prog type prefix to contain a slash "/" for expected attach type BPF_XDP_DEVMAP. This is consistent with other prog types like tracing. Fixes: 2778797037a6 ("libbpf: Add SEC name for xdp programs attached to device map") Suggested-by: Andrii Nakryiko <[email protected]> Signed-off-by: Jesper Dangaard Brouer <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/159309521882.821855.6873145686353617509.stgit@firesoul
2020-06-24selftests/bpf: Implement sample udp/udp6 bpf_iter programsYonghong Song3-0/+166
On my VM, I got identical results between /proc/net/udp[6] and the udp{4,6} bpf iterator. For udp6: $ cat /sys/fs/bpf/p1 sl local_address remote_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode ref pointer drops 1405: 000080FE00000000FF7CC4D0D9EFE4FE:0222 00000000000000000000000000000000:0000 07 00000000:00000000 00:00000000 00000000 193 0 19183 2 0000000029eab111 0 $ cat /proc/net/udp6 sl local_address remote_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode ref pointer drops 1405: 000080FE00000000FF7CC4D0D9EFE4FE:0222 00000000000000000000000000000000:0000 07 00000000:00000000 00:00000000 00000000 193 0 19183 2 0000000029eab111 0 For udp4: $ cat /sys/fs/bpf/p4 sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode ref pointer drops 2007: 00000000:1F90 00000000:0000 07 00000000:00000000 00:00000000 00000000 0 0 72540 2 000000004ede477a 0 $ cat /proc/net/udp sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode ref pointer drops 2007: 00000000:1F90 00000000:0000 07 00000000:00000000 00:00000000 00000000 0 0 72540 2 000000004ede477a 0 Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-24selftests/bpf: Implement sample tcp/tcp6 bpf_iter programsYonghong Song3-0/+499
In my VM, I got identical result compared to /proc/net/{tcp,tcp6}. For tcp6: $ cat /proc/net/tcp6 sl local_address remote_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000000000000000000000000000:0016 00000000000000000000000000000000:0000 0A 00000000:00000000 00:00000001 00000000 0 0 17955 1 000000003eb3102e 100 0 0 10 0 $ cat /sys/fs/bpf/p1 sl local_address remote_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000000000000000000000000000:0016 00000000000000000000000000000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 17955 1 000000003eb3102e 100 0 0 10 0 For tcp: $ cat /proc/net/tcp sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 2666 1 000000007152e43f 100 0 0 10 0 $ cat /sys/fs/bpf/p2 sl local_address remote_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 1: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 2666 1 000000007152e43f 100 0 0 10 0 Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-24selftests/bpf: Add more common macros to bpf_tracing_net.hYonghong Song1-0/+35
These newly added macros will be used in subsequent bpf iterator tcp{4,6} and udp{4,6} programs. Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-24selftests/bpf: Refactor some net macros to bpf_tracing_net.hYonghong Song3-9/+18
Refactor bpf_iter_ipv6_route.c and bpf_iter_netlink.c so net macros, originally from various include/linux header files, are moved to a new header file bpf_tracing_net.h. The goal is to improve reuse so networking tracing programs do not need to copy these macros every time they use them. Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-24selftests/bpf: Move newer bpf_iter_* type redefining to a new header fileYonghong Song9-136/+57
Commit b9f4c01f3e0b ("selftest/bpf: Make bpf_iter selftest compilable against old vmlinux.h") and Commit dda18a5c0b75 ("selftests/bpf: Convert bpf_iter_test_kern{3, 4}.c to define own bpf_iter_meta") redefined newly introduced types in bpf programs so the bpf program can still compile properly with old kernels although loading may fail. Since this patch set introduced new types and the same workaround is needed, so let us move the workaround to a separate header file so they do not clutter bpf programs. Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-24bpf: Add SO_KEEPALIVE and related options to bpf_setsockoptDmitry Yakunin1-0/+27
This patch adds support of SO_KEEPALIVE flag and TCP related options to bpf_setsockopt() routine. This is helpful if we want to enable or tune TCP keepalive for applications which don't do it in the userspace code. v3: - update kernel-doc in uapi (Nikita Vetoshkin <[email protected]>) v4: - update kernel-doc in tools too (Alexei Starovoitov) - add test to selftests (Alexei Starovoitov) Signed-off-by: Dmitry Yakunin <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-24selftests/bpf: Workaround for get_stack_rawtp test.Alexei Starovoitov1-1/+2
./test_progs-no_alu32 -t get_stack_raw_tp fails due to: 52: (85) call bpf_get_stack#67 53: (bf) r8 = r0 54: (bf) r1 = r8 55: (67) r1 <<= 32 56: (c7) r1 s>>= 32 ; if (usize < 0) 57: (c5) if r1 s< 0x0 goto pc+26 R0=inv(id=0,smax_value=800) R1_w=inv(id=0,umax_value=800,var_off=(0x0; 0x3ff)) R6=ctx(id=0,off=0,imm=0) R7=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R8_w=inv(id=0,smax_value=800) R9=inv800 ; ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0); 58: (1f) r9 -= r8 ; ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0); 59: (bf) r2 = r7 60: (0f) r2 += r1 regs=1 stack=0 before 52: (85) call bpf_get_stack#67 ; ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0); 61: (bf) r1 = r6 62: (bf) r3 = r9 63: (b7) r4 = 0 64: (85) call bpf_get_stack#67 R0=inv(id=0,smax_value=800) R1_w=ctx(id=0,off=0,imm=0) R2_w=map_value(id=0,off=0,ks=4,vs=1600,umax_value=800,var_off=(0x0; 0x3ff),s32_max_value=1023,u32_max_value=1023) R3_w=inv(id=0,umax_value=9223372036854776608) R3 unbounded memory access, use 'var &= const' or 'if (var < const)' In the C code: usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK); if (usize < 0) return 0; ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0); if (ksize < 0) return 0; We used to have problem with pointer arith in R2. Now it's a problem with two integers in R3. 'if (usize < 0)' is comparing R1 and makes it [0,800], but R8 stays [-inf,800]. Both registers represent the same 'usize' variable. Then R9 -= R8 is doing 800 - [-inf, 800] so the result of "max_len - usize" looks unbounded to the verifier while it's obvious in C code that "max_len - usize" should be [0, 800]. To workaround the problem convert ksize and usize variables from int to long. Signed-off-by: Alexei Starovoitov <[email protected]>
2020-06-23libbpf: Fix CO-RE relocs against .text sectionAndrii Nakryiko1-1/+1
bpf_object__find_program_by_title(), used by CO-RE relocation code, doesn't return .text "BPF program", if it is a function storage for sub-programs. Because of that, any CO-RE relocation in helper non-inlined functions will fail. Fix this by searching for .text-corresponding BPF program manually. Adjust one of bpf_iter selftest to exhibit this pattern. Fixes: ddc7c3042614 ("libbpf: implement BPF CO-RE offset relocation algorithm") Reported-by: Yonghong Song <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-24selftests/bpf: Add variable-length data concat pattern less than testJohn Fastabend1-4/+66
Extend original variable-length tests with a case to catch a common existing pattern of testing for < 0 for errors. Note because verifier also tracks upper bounds and we know it can not be greater than MAX_LEN here we can skip upper bound check. In ALU64 enabled compilation converting from long->int return types in probe helpers results in extra instruction pattern, <<= 32, s >>= 32. The trade-off is the non-ALU64 case works. If you really care about every extra insn (XDP case?) then you probably should be using original int type. In addition adding a sext insn to bpf might help the verifier in the general case to avoid these types of tricks. Signed-off-by: John Fastabend <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-24selftests/bpf: Add variable-length data concatenation pattern testAndrii Nakryiko1-0/+96
Add selftest that validates variable-length data reading and concatentation with one big shared data array. This is a common pattern in production use for monitoring and tracing applications, that potentially can read a lot of data, but overall read much less. Such pattern allows to determine precisely what amount of data needs to be sent over perfbuf/ringbuf and maximize efficiency. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-22selftests/bpf: Add __ksym extern selftestAndrii Nakryiko1-0/+32
Validate libbpf is able to handle weak and strong kernel symbol externs in BPF code correctly. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Reviewed-by: Hao Luo <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-22selftests/bpf: Test access to bpf map pointerAndrey Ignatov1-0/+686
Add selftests to test access to map pointers from bpf program for all map types except struct_ops (that one would need additional work). verifier test focuses mostly on scenarios that must be rejected. prog_tests test focuses on accessing multiple fields both scalar and a nested struct from bpf program and verifies that those fields have expected values. Signed-off-by: Andrey Ignatov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: John Fastabend <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Link: https://lore.kernel.org/bpf/139a6a17f8016491e39347849b951525335c6eb4.1592600985.git.rdna@fb.com
2020-06-17selftests/bpf: Make sure optvals > PAGE_SIZE are bypassedStanislav Fomichev1-2/+52
We are relying on the fact, that we can pass > sizeof(int) optvals to the SOL_IP+IP_FREEBIND option (the kernel will take first 4 bytes). In the BPF program we check that we can only touch PAGE_SIZE bytes, but the real optlen is PAGE_SIZE * 2. In both cases, we override it to some predefined value and trim the optlen. Also, let's modify exiting IP_TOS usecase to test optlen=0 case where BPF program just bypasses the data as is. Signed-off-by: Stanislav Fomichev <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-12libbpf: Support pre-initializing .bss global variablesAndrii Nakryiko1-4/+15
Remove invalid assumption in libbpf that .bss map doesn't have to be updated in kernel. With addition of skeleton and memory-mapped initialization image, .bss doesn't have to be all zeroes when BPF map is created, because user-code might have initialized those variables from user-space. Fixes: eba9c5f498a1 ("libbpf: Refactor global data map initialization") Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-11selftests/bpf: Add cgroup_skb/egress test for load_bytes_relativeYiFei Zhu1-0/+48
When cgroup_skb/egress triggers the MAC header is not set. Added a test that asserts reading MAC header is a -EFAULT but NET header succeeds. The test result from within the eBPF program is stored in an 1-element array map that the userspace then reads and asserts on. Another assertion is added that reading from a large offset, past the end of packet, returns -EFAULT. Signed-off-by: YiFei Zhu <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Reviewed-by: Stanislav Fomichev <[email protected]> Link: https://lore.kernel.org/bpf/9028ccbea4385a620e69c0a104f469ffd655c01e.1591812755.git.zhuyifei@google.com
2020-06-09bpf: Selftests and tools use struct bpf_devmap_val from uapiJesper Dangaard Brouer2-3/+2
Sync tools uapi bpf.h header file and update selftests that use struct bpf_devmap_val. Signed-off-by: Jesper Dangaard Brouer <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/159170951195.2102545.1833108712124273987.stgit@firesoul
2020-06-02bpf, selftests: Adapt cls_redirect to call csum_level helperDaniel Borkmann1-3/+6
Adapt bpf_skb_adjust_room() to pass in BPF_F_ADJ_ROOM_NO_CSUM_RESET flag and use the new bpf_csum_level() helper to inc/dec the checksum level by one after the encap/decap. Signed-off-by: Daniel Borkmann <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Reviewed-by: Lorenz Bauer <[email protected]> Link: https://lore.kernel.org/bpf/e7458f10e3f3d795307cbc5ad870112671d9c6f7.1591108731.git.daniel@iogearbox.net
2020-06-01selftests/bpf: Convert test_flow_dissector to use BPF skeletonJakub Sitnicki1-10/+10
Switch flow dissector test setup from custom BPF object loader to BPF skeleton to save boilerplate and prepare for testing higher-level API for attaching flow dissector with bpf_link. To avoid depending on program order in the BPF object when populating the flow dissector PROG_ARRAY map, change the program section names to contain the program index into the map. This follows the example set by tailcall tests. Signed-off-by: Jakub Sitnicki <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-06-01selftests/bpf: Add test for SO_BINDTODEVICE opt of bpf_setsockoptFerenc Fejes1-0/+33
This test intended to verify if SO_BINDTODEVICE option works in bpf_setsockopt. Because we already in the SOL_SOCKET level in this connect bpf prog its safe to verify the sanity in the beginning of the connect_v4_prog by calling the bind_to_device test helper. The testing environment already created by the test_sock_addr.sh script so this test assume that two netdevices already existing in the system: veth pair with names test_sock_addr1 and test_sock_addr2. The test will try to bind the socket to those devices first. Then the test assume there are no netdevice with "nonexistent_dev" name so the bpf_setsockopt will give use ENODEV error. At the end the test remove the device binding from the socket by binding it to an empty name. Signed-off-by: Ferenc Fejes <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/3f055b8e45c65639c5c73d0b4b6c589e60b86f15.1590871065.git.fejes@inf.elte.hu
2020-06-01bpf, selftests: Add test for ktls with skb bpf ingress policyJohn Fastabend1-1/+45
This adds a test for bpf ingress policy. To ensure data writes happen as expected with extra TLS headers we run these tests with data verification enabled by default. This will test receive packets have "PASS" stamped into the front of the payload. Signed-off-by: John Fastabend <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/159079363965.5745.3390806911628980210.stgit@john-Precision-5820-Tower Signed-off-by: Alexei Starovoitov <[email protected]>
2020-06-01selftest: Add tests for XDP programs in devmap entriesDavid Ahern2-0/+66
Add tests to verify ability to add an XDP program to a entry in a DEVMAP. Add negative tests to show DEVMAP programs can not be attached to devices as a normal XDP program, and accesses to egress_ifindex require BPF_XDP_DEVMAP attach type. Signed-off-by: David Ahern <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2020-06-01bpf: Add BPF ringbuf and perf buffer benchmarksAndrii Nakryiko2-0/+93
Extend bench framework with ability to have benchmark-provided child argument parser for custom benchmark-specific parameters. This makes bench generic code modular and independent from any specific benchmark. Also implement a set of benchmarks for new BPF ring buffer and existing perf buffer. 4 benchmarks were implemented: 2 variations for each of BPF ringbuf and perfbuf:, - rb-libbpf utilizes stock libbpf ring_buffer manager for reading data; - rb-custom implements custom ring buffer setup and reading code, to eliminate overheads inherent in generic libbpf code due to callback functions and the need to update consumer position after each consumed record, instead of batching updates (due to pessimistic assumption that user callback might take long time and thus could unnecessarily hold ring buffer space for too long); - pb-libbpf uses stock libbpf perf_buffer code with all the default settings, though uses higher-performance raw event callback to minimize unnecessary overhead; - pb-custom implements its own custom consumer code to minimize any possible overhead of generic libbpf implementation and indirect function calls. All of the test support default, no data notification skipped, mode, as well as sampled mode (with --rb-sampled flag), which allows to trigger epoll notification less frequently and reduce overhead. As will be shown, this mode is especially critical for perf buffer, which suffers from high overhead of wakeups in kernel. Otherwise, all benchamrks implement similar way to generate a batch of records by using fentry/sys_getpgid BPF program, which pushes a bunch of records in a tight loop and records number of successful and dropped samples. Each record is a small 8-byte integer, to minimize the effect of memory copying with bpf_perf_event_output() and bpf_ringbuf_output(). Benchmarks that have only one producer implement optional back-to-back mode, in which record production and consumption is alternating on the same CPU. This is the highest-throughput happy case, showing ultimate performance achievable with either BPF ringbuf or perfbuf. All the below scenarios are implemented in a script in benchs/run_bench_ringbufs.sh. Tests were performed on 28-core/56-thread Intel Xeon CPU E5-2680 v4 @ 2.40GHz CPU. Single-producer, parallel producer ================================== rb-libbpf 12.054 ± 0.320M/s (drops 0.000 ± 0.000M/s) rb-custom 8.158 ± 0.118M/s (drops 0.001 ± 0.003M/s) pb-libbpf 0.931 ± 0.007M/s (drops 0.000 ± 0.000M/s) pb-custom 0.965 ± 0.003M/s (drops 0.000 ± 0.000M/s) Single-producer, parallel producer, sampled notification ======================================================== rb-libbpf 11.563 ± 0.067M/s (drops 0.000 ± 0.000M/s) rb-custom 15.895 ± 0.076M/s (drops 0.000 ± 0.000M/s) pb-libbpf 9.889 ± 0.032M/s (drops 0.000 ± 0.000M/s) pb-custom 9.866 ± 0.028M/s (drops 0.000 ± 0.000M/s) Single producer on one CPU, consumer on another one, both running at full speed. Curiously, rb-libbpf has higher throughput than objectively faster (due to more lightweight consumer code path) rb-custom. It appears that faster consumer causes kernel to send notifications more frequently, because consumer appears to be caught up more frequently. Performance of perfbuf suffers from default "no sampling" policy and huge overhead that causes. In sampled mode, rb-custom is winning very significantly eliminating too frequent in-kernel wakeups, the gain appears to be more than 2x. Perf buffer achieves even more impressive wins, compared to stock perfbuf settings, with 10x improvements in throughput with 1:500 sampling rate. The trade-off is that with sampling, application might not get next X events until X+1st arrives, which is not always acceptable. With steady influx of events, though, this shouldn't be a problem. Overall, single-producer performance of ring buffers seems to be better no matter the sampled/non-sampled modes, but it especially beats ring buffer without sampling due to its adaptive notification approach. Single-producer, back-to-back mode ================================== rb-libbpf 15.507 ± 0.247M/s (drops 0.000 ± 0.000M/s) rb-libbpf-sampled 14.692 ± 0.195M/s (drops 0.000 ± 0.000M/s) rb-custom 21.449 ± 0.157M/s (drops 0.000 ± 0.000M/s) rb-custom-sampled 20.024 ± 0.386M/s (drops 0.000 ± 0.000M/s) pb-libbpf 1.601 ± 0.015M/s (drops 0.000 ± 0.000M/s) pb-libbpf-sampled 8.545 ± 0.064M/s (drops 0.000 ± 0.000M/s) pb-custom 1.607 ± 0.022M/s (drops 0.000 ± 0.000M/s) pb-custom-sampled 8.988 ± 0.144M/s (drops 0.000 ± 0.000M/s) Here we test a back-to-back mode, which is arguably best-case scenario both for BPF ringbuf and perfbuf, because there is no contention and for ringbuf also no excessive notification, because consumer appears to be behind after the first record. For ringbuf, custom consumer code clearly wins with 21.5 vs 16 million records per second exchanged between producer and consumer. Sampled mode actually hurts a bit due to slightly slower producer logic (it needs to fetch amount of data available to decide whether to skip or force notification). Perfbuf with wakeup sampling gets 5.5x throughput increase, compared to no-sampling version. There also doesn't seem to be noticeable overhead from generic libbpf handling code. Perfbuf back-to-back, effect of sample rate =========================================== pb-sampled-1 1.035 ± 0.012M/s (drops 0.000 ± 0.000M/s) pb-sampled-5 3.476 ± 0.087M/s (drops 0.000 ± 0.000M/s) pb-sampled-10 5.094 ± 0.136M/s (drops 0.000 ± 0.000M/s) pb-sampled-25 7.118 ± 0.153M/s (drops 0.000 ± 0.000M/s) pb-sampled-50 8.169 ± 0.156M/s (drops 0.000 ± 0.000M/s) pb-sampled-100 8.887 ± 0.136M/s (drops 0.000 ± 0.000M/s) pb-sampled-250 9.180 ± 0.209M/s (drops 0.000 ± 0.000M/s) pb-sampled-500 9.353 ± 0.281M/s (drops 0.000 ± 0.000M/s) pb-sampled-1000 9.411 ± 0.217M/s (drops 0.000 ± 0.000M/s) pb-sampled-2000 9.464 ± 0.167M/s (drops 0.000 ± 0.000M/s) pb-sampled-3000 9.575 ± 0.273M/s (drops 0.000 ± 0.000M/s) This benchmark shows the effect of event sampling for perfbuf. Back-to-back mode for highest throughput. Just doing every 5th record notification gives 3.5x speed up. 250-500 appears to be the point of diminishing return, with almost 9x speed up. Most benchmarks use 500 as the default sampling for pb-raw and pb-custom. Ringbuf back-to-back, effect of sample rate =========================================== rb-sampled-1 1.106 ± 0.010M/s (drops 0.000 ± 0.000M/s) rb-sampled-5 4.746 ± 0.149M/s (drops 0.000 ± 0.000M/s) rb-sampled-10 7.706 ± 0.164M/s (drops 0.000 ± 0.000M/s) rb-sampled-25 12.893 ± 0.273M/s (drops 0.000 ± 0.000M/s) rb-sampled-50 15.961 ± 0.361M/s (drops 0.000 ± 0.000M/s) rb-sampled-100 18.203 ± 0.445M/s (drops 0.000 ± 0.000M/s) rb-sampled-250 19.962 ± 0.786M/s (drops 0.000 ± 0.000M/s) rb-sampled-500 20.881 ± 0.551M/s (drops 0.000 ± 0.000M/s) rb-sampled-1000 21.317 ± 0.532M/s (drops 0.000 ± 0.000M/s) rb-sampled-2000 21.331 ± 0.535M/s (drops 0.000 ± 0.000M/s) rb-sampled-3000 21.688 ± 0.392M/s (drops 0.000 ± 0.000M/s) Similar benchmark for ring buffer also shows a great advantage (in terms of throughput) of skipping notifications. Skipping every 5th one gives 4x boost. Also similar to perfbuf case, 250-500 seems to be the point of diminishing returns, giving roughly 20x better results. Keep in mind, for this test, notifications are controlled manually with BPF_RB_NO_WAKEUP and BPF_RB_FORCE_WAKEUP. As can be seen from previous benchmarks, adaptive notifications based on consumer's positions provides same (or even slightly better due to simpler load generator on BPF side) benefits in favorable back-to-back scenario. Over zealous and fast consumer, which is almost always caught up, will make thoughput numbers smaller. That's the case when manual notification control might prove to be extremely beneficial. Ringbuf back-to-back, reserve+commit vs output ============================================== reserve 22.819 ± 0.503M/s (drops 0.000 ± 0.000M/s) output 18.906 ± 0.433M/s (drops 0.000 ± 0.000M/s) Ringbuf sampled, reserve+commit vs output ========================================= reserve-sampled 15.350 ± 0.132M/s (drops 0.000 ± 0.000M/s) output-sampled 14.195 ± 0.144M/s (drops 0.000 ± 0.000M/s) BPF ringbuf supports two sets of APIs with various usability and performance tradeoffs: bpf_ringbuf_reserve()+bpf_ringbuf_commit() vs bpf_ringbuf_output(). This benchmark clearly shows superiority of reserve+commit approach, despite using a small 8-byte record size. Single-producer, consumer/producer competing on the same CPU, low batch count ============================================================================= rb-libbpf 3.045 ± 0.020M/s (drops 3.536 ± 0.148M/s) rb-custom 3.055 ± 0.022M/s (drops 3.893 ± 0.066M/s) pb-libbpf 1.393 ± 0.024M/s (drops 0.000 ± 0.000M/s) pb-custom 1.407 ± 0.016M/s (drops 0.000 ± 0.000M/s) This benchmark shows one of the worst-case scenarios, in which producer and consumer do not coordinate *and* fight for the same CPU. No batch count and sampling settings were able to eliminate drops for ringbuffer, producer is just too fast for consumer to keep up. But ringbuf and perfbuf still able to pass through quite a lot of messages, which is more than enough for a lot of applications. Ringbuf, multi-producer contention ================================== rb-libbpf nr_prod 1 10.916 ± 0.399M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 2 4.931 ± 0.030M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 3 4.880 ± 0.006M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 4 3.926 ± 0.004M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 8 4.011 ± 0.004M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 12 3.967 ± 0.016M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 16 2.604 ± 0.030M/s (drops 0.001 ± 0.002M/s) rb-libbpf nr_prod 20 2.233 ± 0.003M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 24 2.085 ± 0.015M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 28 2.055 ± 0.004M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 32 1.962 ± 0.004M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 36 2.089 ± 0.005M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 40 2.118 ± 0.006M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 44 2.105 ± 0.004M/s (drops 0.000 ± 0.000M/s) rb-libbpf nr_prod 48 2.120 ± 0.058M/s (drops 0.000 ± 0.001M/s) rb-libbpf nr_prod 52 2.074 ± 0.024M/s (drops 0.007 ± 0.014M/s) Ringbuf uses a very short-duration spinlock during reservation phase, to check few invariants, increment producer count and set record header. This is the biggest point of contention for ringbuf implementation. This benchmark evaluates the effect of multiple competing writers on overall throughput of a single shared ringbuffer. Overall throughput drops almost 2x when going from single to two highly-contended producers, gradually dropping with additional competing producers. Performance drop stabilizes at around 20 producers and hovers around 2mln even with 50+ fighting producers, which is a 5x drop compared to non-contended case. Good kernel implementation in kernel helps maintain decent performance here. Note, that in the intended real-world scenarios, it's not expected to get even close to such a high levels of contention. But if contention will become a problem, there is always an option of sharding few ring buffers across a set of CPUs. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2020-06-01selftests/bpf: Add BPF ringbuf selftestsAndrii Nakryiko2-0/+155
Both singleton BPF ringbuf and BPF ringbuf with map-in-map use cases are tested. Also reserve+submit/discards and output variants of API are validated. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2020-06-01bpf, selftests: Test probe_* helpers from SCHED_CLSJohn Fastabend1-0/+28
Lets test using probe* in SCHED_CLS network programs as well just to be sure these keep working. Its cheap to add the extra test and provides a second context to test outside of sk_msg after we generalized probe* helpers to all networking types. Signed-off-by: John Fastabend <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Yonghong Song <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/159033911685.12355.15951980509828906214.stgit@john-Precision-5820-Tower Signed-off-by: Alexei Starovoitov <[email protected]>
2020-06-01bpf, selftests: Add sk_msg helpers load and attach testJohn Fastabend1-0/+47
The test itself is not particularly useful but it encodes a common pattern we have. Namely do a sk storage lookup then depending on data here decide if we need to do more work or alternatively allow packet to PASS. Then if we need to do more work consult task_struct for more information about the running task. Finally based on this additional information drop or pass the data. In this case the suspicious check is not so realisitic but it encodes the general pattern and uses the helpers so we test the workflow. This is a load test to ensure verifier correctly handles this case. Signed-off-by: John Fastabend <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/159033909665.12355.6166415847337547879.stgit@john-Precision-5820-Tower Signed-off-by: Alexei Starovoitov <[email protected]>