kernel/linux.git/samples/bpf, branch v5.10.7

samples/bpf: Fix possible hang in xdpsock with multiple threads

2020-12-30T10:53:49+00:00

[ Upstream commit 092fde0f863b72b67c4d6dc03844f5658fc00a35 ] Fix a possible hang in xdpsock that can occur when using multiple threads. In this case, one or more of the threads might get stuck in the while-loop in tx_only after the user has signaled the main thread to stop execution. In this case, no more Tx packets will be sent, so a thread might get stuck in the aforementioned while-loop. Fix this by introducing a test inside the while-loop to check if the benchmark has been terminated. If so, return from the function. Fixes: cd9e72b6f210 ("samples/bpf: xdpsock: Add option to specify batch size") Signed-off-by: Magnus Karlsson Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20201210163407.22066-1-magnus.karlsson@gmail.com Signed-off-by: Sasha Levin

samples: bpf: Fix lwt_len_hist reusing previous BPF map

2020-12-30T10:53:23+00:00

[ Upstream commit 0afe0a998c40085a6342e1aeb4c510cccba46caf ] Currently, lwt_len_hist's map lwt_len_hist_map is uses pinning, and the map isn't cleared on test end. This leds to reuse of that map for each test, which prevents the results of the test from being accurate. This commit fixes the problem by removing of pinned map from bpffs. Also, this commit add the executable permission to shell script files. Fixes: f74599f7c5309 ("bpf: Add tests and samples for LWT-BPF") Signed-off-by: Daniel T. Lee Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201124090310.24374-7-danieltimlee@gmail.com Signed-off-by: Sasha Levin

samples/bpf: Set rlimit for memlock to infinity in all samples

2020-10-27T21:46:17+00:00

The memlock rlimit is a notorious source of failure for BPF programs. Most of the samples just set it to infinity, but a few used a lower limit. The problem with unconditionally setting a lower limit is that this will also override the limit if the system-wide setting is *higher* than the limit being set, which can lead to failures on systems that lock a lot of memory, but set 'ulimit -l' to unlimited before running a sample. One fix for this is to only conditionally set the limit if the current limit is lower, but it is simpler to just unify all the samples and have them all set the limit to infinity. Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/bpf/20201026233623.91728-1-toke@redhat.com

bpf, libbpf: Guard bpf inline asm from bpf_tail_call_static

2020-10-21T23:46:52+00:00

Yaniv reported a compilation error after pulling latest libbpf: [...] ../libbpf/src/root/usr/include/bpf/bpf_helpers.h:99:10: error: unknown register name 'r0' in asm : "r0", "r1", "r2", "r3", "r4", "r5"); [...] The issue got triggered given Yaniv was compiling tracing programs with native target (e.g. x86) instead of BPF target, hence no BTF generated vmlinux.h nor CO-RE used, and later llc with -march=bpf was invoked to compile from LLVM IR to BPF object file. Given that clang was expecting x86 inline asm and not BPF one the error complained that these regs don't exist on the former. Guard bpf_tail_call_static() with defined(__bpf__) where BPF inline asm is valid to use. BPF tracing programs on more modern kernels use BPF target anyway and thus the bpf_tail_call_static() function will be available for them. BPF inline asm is supported since clang 7 (clang <= 6 otherwise throws same above error), and __bpf_unreachable() since clang 8, therefore include the latter condition in order to prevent compilation errors for older clang versions. Given even an old Ubuntu 18.04 LTS has official LLVM packages all the way up to llvm-10, I did not bother to special case the __bpf_unreachable() inside bpf_tail_call_static() further. Also, undo the sockex3_kern's use of bpf_tail_call_static() sample given they still have the old hacky way to even compile networking progs with native instead of BPF target so bpf_tail_call_static() won't be defined there anymore. Fixes: 0e9f6841f664 ("bpf, libbpf: Add bpf_tail_call_static helper for bpf programs") Reported-by: Yaniv Agman Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Acked-by: Yonghong Song Tested-by: Yaniv Agman Link: https://lore.kernel.org/bpf/CAMy7=ZUk08w5Gc2Z-EKi4JFtuUCaZYmE4yzhJjrExXpYKR4L8w@mail.gmail.com Link: https://lore.kernel.org/bpf/20201021203257.26223-1-daniel@iogearbox.net

samples: bpf: Refactor XDP kern program maps with BTF-defined map

2020-10-11T19:14:36+00:00

Most of the samples were converted to use the new BTF-defined MAP as they moved to libbpf, but some of the samples were missing. Instead of using the previous BPF MAP definition, this commit refactors xdp_monitor and xdp_sample_pkts_kern MAP definition with the new BTF-defined MAP format. Also, this commit removes the max_entries attribute at PERF_EVENT_ARRAY map type. The libbpf's bpf_object__create_map() will automatically set max_entries to the maximum configured number of CPUs on the host. Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201010181734.1109-4-danieltimlee@gmail.com

samples: bpf: Replace attach_tracepoint() to attach() in xdp_redirect_cpu

2020-10-11T19:14:36+00:00

>From commit d7a18ea7e8b6 ("libbpf: Add generic bpf_program__attach()"), for some BPF programs, it is now possible to attach BPF programs with __attach() instead of explicitly calling __attach_(). This commit refactors the __attach_tracepoint() with libbpf's generic __attach() method. In addition, this refactors the logic of setting the map FD to simplify the code. Also, the missing removal of bpf_load.o in Makefile has been fixed. Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201010181734.1109-3-danieltimlee@gmail.com

samples: bpf: Refactor xdp_monitor with libbpf

2020-10-11T19:14:36+00:00

To avoid confusion caused by the increasing fragmentation of the BPF Loader program, this commit would like to change to the libbpf loader instead of using the bpf_load. Thanks to libbpf's bpf_link interface, managing the tracepoint BPF program is much easier. bpf_program__attach_tracepoint manages the enable of tracepoint event and attach of BPF programs to it with a single interface bpf_link, so there is no need to manage event_fd and prog_fd separately. This commit refactors xdp_monitor with using this libbpf API, and the bpf_load is removed and migrated to libbpf. Signed-off-by: Daniel T. Lee Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201010181734.1109-2-danieltimlee@gmail.com

samples: bpf: Driver interrupt statistics in xdpsock

2020-10-06T18:46:50+00:00

Add an option to count the number of interrupts generated per second and total number of interrupts during the lifetime of the application for a given interface. This information is extracted from /proc/interrupts. Since there is no naming convention across drivers, the user must provide the string which is specific to their interface in the /proc/interrupts file on the command line. Usage: ./xdpsock ... -I eg. for queue 0 of i40e device eth0: ./xdpsock ... -I i40e-eth0-TxRx-0 Signed-off-by: Ciara Loftus Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20201002133612.31536-3-ciara.loftus@intel.com

samples: bpf: Count syscalls in xdpsock

2020-10-06T18:46:50+00:00

Categorise and record syscalls issued in the xdpsock sample app. The categories recorded are: rx_empty_polls: polls when the rx ring is empty fill_fail_polls: polls when failed to get addr from fill ring copy_tx_sendtos: sendtos issued for tx when copy mode enabled tx_wakeup_sendtos: sendtos issued when tx ring needs waking up opt_polls: polls issued since the '-p' flag is set Print the stats using '-a' on the xdpsock command line. Signed-off-by: Ciara Loftus Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20201002133612.31536-2-ciara.loftus@intel.com

samples: bpf: Split xdpsock stats into new struct

2020-10-06T18:46:50+00:00

New statistics will be added in future commits. In preparation for this, let's split out the existing statistics into their own struct. Signed-off-by: Ciara Loftus Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20201002133612.31536-1-ciara.loftus@intel.com