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2018-02-02libbpf: add error reporting in XDPEric Leblond1-1/+1
Parse netlink ext attribute to get the error message returned by the card. Code is partially take from libnl. We add netlink.h to the uapi include of tools. And we need to avoid include of userspace netlink header to have a successful build of sample so nlattr.h has a define to avoid the inclusion. Using a direct define could have been an issue as NLMSGERR_ATTR_MAX can change in the future. We also define SOL_NETLINK if not defined to avoid to have to copy socket.h for a fixed value. Signed-off-by: Eric Leblond <eric@regit.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-26samples/bpf: Partially fixes the bpf.o buildMickaël Salaün1-1/+4
Do not build lib/bpf/bpf.o with this Makefile but use the one from the library directory. This avoid making a buggy bpf.o file (e.g. missing symbols). This patch is useful if some code (e.g. Landlock tests) needs both the bpf.o (from tools/lib/bpf) and the bpf_load.o (from samples/bpf). Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-11samples/bpf: xdp2skb_meta shows transferring info from XDP to SKBJesper Dangaard Brouer1-0/+1
Creating a bpf sample that shows howto use the XDP 'data_meta' infrastructure, created by Daniel Borkmann. Very few drivers support this feature, but I wanted a functional sample to begin with, when working on adding driver support. XDP data_meta is about creating a communication channel between BPF programs. This can be XDP tail-progs, but also other SKB based BPF hooks, like in this case the TC clsact hook. In this sample I show that XDP can store info named "mark", and TC/clsact chooses to use this info and store it into the skb->mark. It is a bit annoying that XDP and TC samples uses different tools/libs when attaching their BPF hooks. As the XDP and TC programs need to cooperate and agree on a struct-layout, it is best/easiest if the two programs can be contained within the same BPF restricted-C file. As the bpf-loader, I choose to not use bpf_load.c (or libbpf), but instead wrote a bash shell scripted named xdp2skb_meta.sh, which demonstrate howto use the iproute cmdline tools 'tc' and 'ip' for loading BPF programs. To make it easy for first time users, the shell script have command line parsing, and support --verbose and --dry-run mode, if you just want to see/learn the tc+ip command syntax: # ./xdp2skb_meta.sh --dev ixgbe2 --dry-run # Dry-run mode: enable VERBOSE and don't call TC+IP tc qdisc del dev ixgbe2 clsact tc qdisc add dev ixgbe2 clsact tc filter add dev ixgbe2 ingress prio 1 handle 1 bpf da obj ./xdp2skb_meta_kern.o sec tc_mark # Flush XDP on device: ixgbe2 ip link set dev ixgbe2 xdp off ip link set dev ixgbe2 xdp obj ./xdp2skb_meta_kern.o sec xdp_mark Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-05samples/bpf: program demonstrating access to xdp_rxq_infoJesper Dangaard Brouer1-0/+4
This sample program can be used for monitoring and reporting how many packets per sec (pps) are received per NIC RX queue index and which CPU processed the packet. In itself it is a useful tool for quickly identifying RSS imbalance issues, see below. The default XDP action is XDP_PASS in-order to provide a monitor mode. For benchmarking purposes it is possible to specify other XDP actions on the cmdline --action. Output below shows an imbalance RSS case where most RXQ's deliver to CPU-0 while CPU-2 only get packets from a single RXQ. Looking at things from a CPU level the two CPUs are processing approx the same amount, BUT looking at the rx_queue_index levels it is clear that RXQ-2 receive much better service, than other RXQs which all share CPU-0. Running XDP on dev:i40e1 (ifindex:3) action:XDP_PASS XDP stats CPU pps issue-pps XDP-RX CPU 0 900,473 0 XDP-RX CPU 2 906,921 0 XDP-RX CPU total 1,807,395 RXQ stats RXQ:CPU pps issue-pps rx_queue_index 0:0 180,098 0 rx_queue_index 0:sum 180,098 rx_queue_index 1:0 180,098 0 rx_queue_index 1:sum 180,098 rx_queue_index 2:2 906,921 0 rx_queue_index 2:sum 906,921 rx_queue_index 3:0 180,098 0 rx_queue_index 3:sum 180,098 rx_queue_index 4:0 180,082 0 rx_queue_index 4:sum 180,082 rx_queue_index 5:0 180,093 0 rx_queue_index 5:sum 180,093 Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12samples/bpf: add a test for bpf_override_returnJosef Bacik1-0/+4
This adds a basic test for bpf_override_return to verify it works. We override the main function for mounting a btrfs fs so it'll return -ENOMEM and then make sure that trying to mount a btrfs fs will fail. Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-11-18kbuild: remove all dummy assignments to obj-Masahiro Yamada1-3/+0
Now kbuild core scripts create empty built-in.o where necessary. Remove "obj- := dummy.o" tricks. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-11-11bpf: Revert bpf_overrid_function() helper changes.David S. Miller1-4/+0
NACK'd by x86 maintainer. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-11samples/bpf: add a test for bpf_override_returnJosef Bacik1-0/+4
This adds a basic test for bpf_override_return to verify it works. We override the main function for mounting a btrfs fs so it'll return -ENOMEM and then make sure that trying to mount a btrfs fs will fail. Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-08xdp: Sample xdp program implementing ip forwardChristina Jacob1-0/+4
Implements port to port forwarding with route table and arp table lookup for ipv4 packets using bpf_redirect helper function and lpm_trie map. Signed-off-by: Christina Jacob <Christina.Jacob@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-05bpf: move cgroup_helpers from samples/bpf/ to tools/testing/selftesting/bpf/Roman Gushchin1-2/+3
The purpose of this move is to use these files in bpf tests. Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-0/+1
Files removed in 'net-next' had their license header updated in 'net'. We take the remove from 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-22bpf: sample BPF_SOCKET_OPS_BASE_RTT programLawrence Brakmo1-0/+1
Sample socket_ops BPF program to test the BPF helper function bpf_getsocketops and the new socket_ops op BPF_SOCKET_OPS_BASE_RTT. The program provides a base RTT of 80us when the calling flow is within a DC (as determined by the IPV6 prefix) and the congestion algorithm is "nv". Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked_by: Alexei Starovoitov <ast@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-18samples/bpf: add cpumap sample program xdp_redirect_cpuJesper Dangaard Brouer1-0/+4
This sample program show how to use cpumap and the associated tracepoints. It provides command line stats, which shows how the XDP-RX process, cpumap-enqueue and cpumap kthread dequeue is cooperating on a per CPU basis. It also utilize the xdp_exception and xdp_redirect_err transpoints to allow users quickly to identify setup issues. One issue with ixgbe driver is that the driver reset the link when loading XDP. This reset the procfs smp_affinity settings. Thus, after loading the program, these must be reconfigured. The easiest workaround it to reduce the RX-queue to e.g. two via: # ethtool --set-channels ixgbe1 combined 2 And then add CPUs above 0 and 1, like: # xdp_redirect_cpu --dev ixgbe1 --prog 2 --cpu 2 --cpu 3 --cpu 4 Another issue with ixgbe is that the page recycle mechanism is tied to the RX-ring size. And the default setting of 512 elements is too small. This is the same issue with regular devmap XDP_REDIRECT. To overcome this I've been using 1024 rx-ring size: # ethtool -G ixgbe1 rx 1024 tx 1024 V3: - whitespace cleanups - bpf tracepoint cannot access top part of struct V4: - report on kthread sched events, according to tracepoint change - report average bulk enqueue size V5: - bpf_map_lookup_elem on cpumap not allowed from bpf_prog use separate map to mark CPUs not available V6: - correct kthread sched summary output V7: - Added a --stress-mode for concurrently changing underlying cpumap Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16bpf: Add -target to clang switch while cross compiling.Abhijit Ayarekar1-2/+3
Update to llvm excludes assembly instructions. llvm git revision is below commit 65fad7c26569 ("bpf: add inline-asm support") This change will be part of llvm release 6.0 __ASM_SYSREG_H define is not required for native compile. -target switch includes appropriate target specific files while cross compiling Tested on x86 and arm64. Signed-off-by: Abhijit Ayarekar <abhijit.ayarekar@caviumnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-21samples/bpf: Fix pt_regs issues when cross-compilingJoel Fernandes1-1/+1
BPF samples fail to build when cross-compiling for ARM64 because of incorrect pt_regs param selection. This is because clang defines __x86_64__ and bpf_headers thinks we're building for x86. Since clang is building for the BPF target, it shouldn't make assumptions about what target the BPF program is going to run on. To fix this, lets pass ARCH so the header knows which target the BPF program is being compiled for and can use the correct pt_regs code. Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Joel Fernandes <joelaf@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-21samples/bpf: Enable cross compiler supportJoel Fernandes1-0/+5
When cross compiling, bpf samples use HOSTCC for compiling the non-BPF part of the sample, however what we really want is to use the cross compiler to build for the cross target since that is what will load and run the BPF sample. Detect this and compile samples correctly. Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Joel Fernandes <joelaf@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-29samples/bpf: xdp_monitor tool based on tracepointsJesper Dangaard Brouer1-0/+4
This tool xdp_monitor demonstrate how to use the different xdp_redirect tracepoints xdp_redirect{,_map}{,_err} from a BPF program. The default mode is to only monitor the error counters, to avoid affecting the per packet performance. Tracepoints comes with a base overhead of 25 nanosec for an attached bpf_prog, and 48 nanosec for using a full perf record (with non-matching filter). Thus, default loading the --stats mode could affect the maximum performance. This version of the tool is very simple and count all types of errors as one. It will be natural to extend this later with the different types of errors that can occur, which should help users quickly identify common mistakes. Because the TP_STRUCT was kept in sync all the tracepoints loads the same BPF code. It would also be natural to extend the map version to demonstrate how the map information could be used. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07bpf: add a test case for syscalls/sys_{enter|exit}_* tracepointsYonghong Song1-0/+4
Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-17xdp: bpf redirect with map sample programJohn Fastabend1-0/+4
Signed-off-by: John Fastabend <john.fastabend@gmail.com> Tested-by: Andy Gospodarek <andy@greyhouse.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-17xdp: sample program for new bpf_redirect helperJohn Fastabend1-0/+4
This implements a sample program for testing bpf_redirect. It reports the number of packets redirected per second and as input takes the ifindex of the device to run the xdp program on and the ifindex of the interface to redirect packets to. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Tested-by: Andy Gospodarek <andy@greyhouse.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-11samples/bpf: fix a build issueYonghong Song1-0/+1
With latest net-next: ==== clang -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/6.3.1/include -I./arch/x86/include -I./arch/x86/include/generated/uapi -I./arch/x86/include/generated -I./include -I./arch/x86/include/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h -Isamples/bpf \ -D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \ -Wno-compare-distinct-pointer-types \ -Wno-gnu-variable-sized-type-not-at-end \ -Wno-address-of-packed-member -Wno-tautological-compare \ -Wno-unknown-warning-option \ -O2 -emit-llvm -c samples/bpf/tcp_synrto_kern.c -o -| llc -march=bpf -filetype=obj -o samples/bpf/tcp_synrto_kern.o samples/bpf/tcp_synrto_kern.c:20:10: fatal error: 'bpf_endian.h' file not found ^~~~~~~~~~~~~~ 1 error generated. ==== net has the same issue. Add support for ntohl and htonl in tools/testing/selftests/bpf/bpf_endian.h. Also move bpf_helpers.h from samples/bpf to selftests/bpf and change compiler include logic so that programs in samples/bpf can access the headers in selftests/bpf, but not the other way around. Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01bpf: Sample bpf program to set sndcwnd clampLawrence Brakmo1-0/+1
Sample BPF program, tcp_clamp_kern.c, to demostrate the use of setting the sndcwnd clamp. This program assumes that if the first 5.5 bytes of the host's IPv6 addresses are the same, then the hosts are in the same datacenter and sets sndcwnd clamp to 100 packets, SYN and SYN-ACK RTOs to 10ms and send/receive buffer sizes to 150KB. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01bpf: Sample BPF program to set initial cwndLawrence Brakmo1-0/+1
Sample BPF program that assumes hosts are far away (i.e. large RTTs) and sets initial cwnd and initial receive window to 40 packets, send and receive buffers to 1.5MB. In practice there would be a test to insure the hosts are actually far enough away. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01bpf: Sample BPF program to set congestion controlLawrence Brakmo1-0/+1
Sample BPF program that sets congestion control to dctcp when both hosts are within the same datacenter. In this example that is assumed to be when they have the first 5.5 bytes of their IPv6 address are the same. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01bpf: Sample BPF program to set buffer sizesLawrence Brakmo1-0/+1
This patch contains a BPF program to set initial receive window to 40 packets and send and receive buffers to 1.5MB. This would usually be done after doing appropriate checks that indicate the hosts are far enough away (i.e. large RTT). Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01bpf: Sample bpf program to set initial windowLawrence Brakmo1-0/+1
The sample bpf program, tcp_rwnd_kern.c, sets the initial advertized window to 40 packets in an environment where distinct IPv6 prefixes indicate that both hosts are not in the same data center. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01bpf: Sample bpf program to set SYN/SYN-ACK RTOsLawrence Brakmo1-0/+1
The sample BPF program, tcp_synrto_kern.c, sets the SYN and SYN-ACK RTOs to 10ms when both hosts are within the same datacenter (i.e. small RTTs) in an environment where common IPv6 prefixes indicate both hosts are in the same data center. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01bpf: program to load and attach sock_ops BPF progsLawrence Brakmo1-0/+3
The program load_sock_ops can be used to load sock_ops bpf programs and to attach it to an existing (v2) cgroup. It can also be used to detach sock_ops programs. Examples: load_sock_ops [-l] <cg-path> <prog filename> Load and attaches a sock_ops program at the specified cgroup. If "-l" is used, the program will continue to run to output the BPF log buffer. If the specified filename does not end in ".o", it appends "_kern.o" to the name. load_sock_ops -r <cg-path> Detaches the currently attached sock_ops program from the specified cgroup. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-22samples/bpf: fix a build problemYonghong Song1-1/+1
tracex5_kern.c build failed with the following error message: ../samples/bpf/tracex5_kern.c:12:10: fatal error: 'syscall_nrs.h' file not found #include "syscall_nrs.h" The generated file syscall_nrs.h is put in build/samples/bpf directory, but this directory is not in include path, hence build failed. The fix is to add $(obj) into the clang compilation path. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14samples/bpf: Fix tracex5 to work with MIPS syscalls.David Daney1-0/+13
There are two problems: 1) In MIPS the __NR_* macros expand to an expression, this causes the sections of the object file to be named like: . . . [ 5] kprobe/(5000 + 1) PROGBITS 0000000000000000 000160 ... [ 6] kprobe/(5000 + 0) PROGBITS 0000000000000000 000258 ... [ 7] kprobe/(5000 + 9) PROGBITS 0000000000000000 000348 ... . . . The fix here is to use the "asm_offsets" trick to evaluate the macros in the C compiler and generate a header file with a usable form of the macros. 2) MIPS syscall numbers start at 5000, so we need a bigger map to hold the sub-programs. Signed-off-by: David Daney <david.daney@cavium.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-24samples/bpf: add -Wno-unknown-warning-option to clangAlexander Alemayhu1-0/+1
I was initially going to remove '-Wno-address-of-packed-member' because I thought it was not supposed to be there but Daniel suggested using '-Wno-unknown-warning-option'. This silences several warnings similiar to the one below warning: unknown warning option '-Wno-address-of-packed-member' [-Wunknown-warning-option] 1 warning generated. clang -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/6.3.1/include -I./arch/x86/include -I./arch/x86/include/generated/uapi -I./arch/x86/include/generated -I./include -I./arch/x86/include/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h \ -D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \ -Wno-compare-distinct-pointer-types \ -Wno-gnu-variable-sized-type-not-at-end \ -Wno-address-of-packed-member -Wno-tautological-compare \ -O2 -emit-llvm -c samples/bpf/xdp_tx_iptunnel_kern.c -o -| llc -march=bpf -filetype=obj -o samples/bpf/xdp_tx_iptunnel_kern.o $ clang --version clang version 3.9.1 (tags/RELEASE_391/final) Target: x86_64-unknown-linux-gnu Thread model: posix InstalledDir: /usr/bin Signed-off-by: Alexander Alemayhu <alexander@alemayhu.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-23A Sample of using socket cookie and uid for traffic monitoringChenbo Feng1-0/+3
Add a sample program to demostrate the possible usage of get_socket_cookie and get_socket_uid helper function. The program will store bytes and packets counting of in/out traffic monitored by iptables and store the stats in a bpf map in per socket base. The owner uid of the socket will be stored as part of the data entry. A shell script for running the program is also included. Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Chenbo Feng <fengc@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22bpf: Add tests for map-in-mapMartin KaFai Lau1-0/+4
Test cases for array of maps and hash of maps. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-23Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-32/+38
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "On the kernel side there's two x86 PMU driver fixes and a uprobes fix, plus on the tooling side there's a number of fixes and some late updates" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) perf sched timehist: Fix invalid period calculation perf sched timehist: Remove hardcoded 'comm_width' check at print_summary perf sched timehist: Enlarge default 'comm_width' perf sched timehist: Honour 'comm_width' when aligning the headers perf/x86: Fix overlap counter scheduling bug perf/x86/pebs: Fix handling of PEBS buffer overflows samples/bpf: Move open_raw_sock to separate header samples/bpf: Remove perf_event_open() declaration samples/bpf: Be consistent with bpf_load_program bpf_insn parameter tools lib bpf: Add bpf_prog_{attach,detach} samples/bpf: Switch over to libbpf perf diff: Do not overwrite valid build id perf annotate: Don't throw error for zero length symbols perf bench futex: Fix lock-pi help string perf trace: Check if MAP_32BIT is defined (again) samples/bpf: Make perf_event_read() static uprobes: Fix uprobes on MIPS, allow for a cache flush after ixol breakpoint creation samples/bpf: Make samples more libbpf-centric tools lib bpf: Add flags to bpf_create_map() tools lib bpf: use __u32 from linux/types.h ...
2016-12-20samples/bpf: Move open_raw_sock to separate headerJoe Stringer1-1/+1
This function was declared in libbpf.c and was the only remaining function in this library, but has nothing to do with BPF. Shift it out into a new header, sock_example.h, and include it from the relevant samples. Signed-off-by: Joe Stringer <joe@ovn.org> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/20161209024620.31660-8-joe@ovn.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-12-20samples/bpf: Remove perf_event_open() declarationJoe Stringer1-0/+2
This declaration was made in samples/bpf/libbpf.c for convenience, but there's already one in tools/perf/perf-sys.h. Reuse that one. Committer notes: Testing it: $ make -j4 O=../build/v4.9.0-rc8+ samples/bpf/ make[1]: Entering directory '/home/build/v4.9.0-rc8+' CHK include/config/kernel.release GEN ./Makefile CHK include/generated/uapi/linux/version.h Using /home/acme/git/linux as source for kernel CHK include/generated/utsrelease.h CHK include/generated/timeconst.h CHK include/generated/bounds.h CHK include/generated/asm-offsets.h CALL /home/acme/git/linux/scripts/checksyscalls.sh HOSTCC samples/bpf/test_verifier.o HOSTCC samples/bpf/libbpf.o HOSTCC samples/bpf/../../tools/lib/bpf/bpf.o HOSTCC samples/bpf/test_maps.o HOSTCC samples/bpf/sock_example.o HOSTCC samples/bpf/bpf_load.o <SNIP> HOSTLD samples/bpf/trace_event HOSTLD samples/bpf/sampleip HOSTLD samples/bpf/tc_l2_redirect make[1]: Leaving directory '/home/build/v4.9.0-rc8+' $ Also tested the offwaketime resulting from the rebuild, seems to work as before. Signed-off-by: Joe Stringer <joe@ovn.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/20161209024620.31660-7-joe@ovn.org [ Use -I$(srctree)/tools/lib/ to support out of source code tree builds ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-12-20samples/bpf: Switch over to libbpfJoe Stringer1-32/+36
Now that libbpf under tools/lib/bpf/* is synced with the version from samples/bpf, we can get rid most of the libbpf library here. Committer notes: Built it in a docker fedora rawhide container and ran it in the f25 host, seems to work just like it did before this patch, i.e. the switch to tools/lib/bpf/ doesn't seem to have introduced problems and Joe said he tested it with all the entries in samples/bpf/ and other code he found: [root@f5065a7d6272 linux]# make -j4 O=/tmp/build/linux headers_install <SNIP> [root@f5065a7d6272 linux]# rm -rf /tmp/build/linux/samples/bpf/ [root@f5065a7d6272 linux]# make -j4 O=/tmp/build/linux samples/bpf/ make[1]: Entering directory '/tmp/build/linux' CHK include/config/kernel.release HOSTCC scripts/basic/fixdep GEN ./Makefile CHK include/generated/uapi/linux/version.h Using /git/linux as source for kernel CHK include/generated/utsrelease.h HOSTCC scripts/basic/bin2c HOSTCC arch/x86/tools/relocs_32.o HOSTCC arch/x86/tools/relocs_64.o LD samples/bpf/built-in.o <SNIP> HOSTCC samples/bpf/fds_example.o HOSTCC samples/bpf/sockex1_user.o /git/linux/samples/bpf/fds_example.c: In function 'bpf_prog_create': /git/linux/samples/bpf/fds_example.c:63:6: warning: passing argument 2 of 'bpf_load_program' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] insns, insns_cnt, "GPL", 0, ^~~~~ In file included from /git/linux/samples/bpf/libbpf.h:5:0, from /git/linux/samples/bpf/bpf_load.h:4, from /git/linux/samples/bpf/fds_example.c:15: /git/linux/tools/lib/bpf/bpf.h:31:5: note: expected 'struct bpf_insn *' but argument is of type 'const struct bpf_insn *' int bpf_load_program(enum bpf_prog_type type, struct bpf_insn *insns, ^~~~~~~~~~~~~~~~ HOSTCC samples/bpf/sockex2_user.o <SNIP> HOSTCC samples/bpf/xdp_tx_iptunnel_user.o clang -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/6.2.1/include -I/git/linux/arch/x86/include -I./arch/x86/include/generated/uapi -I./arch/x86/include/generated -I/git/linux/include -I./include -I/git/linux/arch/x86/include/uapi -I/git/linux/include/uapi -I./include/generated/uapi -include /git/linux/include/linux/kconfig.h \ -D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \ -Wno-compare-distinct-pointer-types \ -Wno-gnu-variable-sized-type-not-at-end \ -Wno-address-of-packed-member -Wno-tautological-compare \ -O2 -emit-llvm -c /git/linux/samples/bpf/sockex1_kern.c -o -| llc -march=bpf -filetype=obj -o samples/bpf/sockex1_kern.o HOSTLD samples/bpf/tc_l2_redirect <SNIP> HOSTLD samples/bpf/lwt_len_hist HOSTLD samples/bpf/xdp_tx_iptunnel make[1]: Leaving directory '/tmp/build/linux' [root@f5065a7d6272 linux]# And then, in the host: [root@jouet bpf]# mount | grep "docker.*devicemapper\/" /dev/mapper/docker-253:0-1705076-9bd8aa1e0af33adce89ff42090847868ca676932878942be53941a06ec5923f9 on /var/lib/docker/devicemapper/mnt/9bd8aa1e0af33adce89ff42090847868ca676932878942be53941a06ec5923f9 type xfs (rw,relatime,context="system_u:object_r:container_file_t:s0:c73,c276",nouuid,attr2,inode64,sunit=1024,swidth=1024,noquota) [root@jouet bpf]# cd /var/lib/docker/devicemapper/mnt/9bd8aa1e0af33adce89ff42090847868ca676932878942be53941a06ec5923f9/rootfs/tmp/build/linux/samples/bpf/ [root@jouet bpf]# file offwaketime offwaketime: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=f423d171e0487b2f802b6a792657f0f3c8f6d155, not stripped [root@jouet bpf]# readelf -SW offwaketime offwaketime offwaketime_kern.o offwaketime_user.o [root@jouet bpf]# readelf -SW offwaketime_kern.o There are 11 section headers, starting at offset 0x700: Section Headers: [Nr] Name Type Address Off Size ES Flg Lk Inf Al [ 0] NULL 0000000000000000 000000 000000 00 0 0 0 [ 1] .strtab STRTAB 0000000000000000 000658 0000a8 00 0 0 1 [ 2] .text PROGBITS 0000000000000000 000040 000000 00 AX 0 0 4 [ 3] kprobe/try_to_wake_up PROGBITS 0000000000000000 000040 0000d8 00 AX 0 0 8 [ 4] .relkprobe/try_to_wake_up REL 0000000000000000 0005a8 000020 10 10 3 8 [ 5] tracepoint/sched/sched_switch PROGBITS 0000000000000000 000118 000318 00 AX 0 0 8 [ 6] .reltracepoint/sched/sched_switch REL 0000000000000000 0005c8 000090 10 10 5 8 [ 7] maps PROGBITS 0000000000000000 000430 000050 00 WA 0 0 4 [ 8] license PROGBITS 0000000000000000 000480 000004 00 WA 0 0 1 [ 9] version PROGBITS 0000000000000000 000484 000004 00 WA 0 0 4 [10] .symtab SYMTAB 0000000000000000 000488 000120 18 1 4 8 Key to Flags: W (write), A (alloc), X (execute), M (merge), S (strings) I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown) O (extra OS processing required) o (OS specific), p (processor specific) [root@jouet bpf]# ./offwaketime | head -3 qemu-system-x86;entry_SYSCALL_64_fastpath;sys_ppoll;do_sys_poll;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;__schedule;-;try_to_wake_up;hrtimer_wakeup;__hrtimer_run_queues;hrtimer_interrupt;local_apic_timer_interrupt;smp_apic_timer_interrupt;__irqentry_text_start;cpuidle_enter_state;cpuidle_enter;call_cpuidle;cpu_startup_entry;rest_init;start_kernel;x86_64_start_reservations;x86_64_start_kernel;start_cpu;;swapper/0 4 firefox;entry_SYSCALL_64_fastpath;sys_poll;do_sys_poll;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;__schedule;-;try_to_wake_up;pollwake;__wake_up_common;__wake_up_sync_key;pipe_write;__vfs_write;vfs_write;sys_write;entry_SYSCALL_64_fastpath;;Timer 1 swapper/2;start_cpu;start_secondary;cpu_startup_entry;schedule_preempt_disabled;schedule;__schedule;-;---;; 61 [root@jouet bpf]# Signed-off-by: Joe Stringer <joe@ovn.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Wang Nan <wangnan0@huawei.com> Cc: netdev@vger.kernel.org Link: https://github.com/joestringer/linux/commit/5c40f54a52b1f437123c81e21873f4b4b1f9bd55.patch Link: http://lkml.kernel.org/n/tip-xr8twtx7sjh5821g8qw47yxk@git.kernel.org [ Use -I$(srctree)/tools/lib/ to support out of source code tree builds, as noticed by Wang Nan ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-12-17Merge branch 'kbuild' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull kbuild updates from Michal Marek: - prototypes for x86 asm-exported symbols (Adam Borowski) and a warning about missing CRCs (Nick Piggin) - asm-exports fix for LTO (Nicolas Pitre) - thin archives improvements (Nick Piggin) - linker script fix for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION (Nick Piggin) - genksyms support for __builtin_va_list keyword - misc minor fixes * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: x86/kbuild: enable modversions for symbols exported from asm kbuild: fix scripts/adjust_autoksyms.sh* for the no modules case scripts/kallsyms: remove last remnants of --page-offset option make use of make variable CURDIR instead of calling pwd kbuild: cmd_export_list: tighten the sed script kbuild: minor improvement for thin archives build kbuild: modpost warn if export version crc is missing kbuild: keep data tables through dead code elimination kbuild: improve linker compatibility with lib-ksyms.o build genksyms: Regenerate parser kbuild/genksyms: handle va_list type kbuild: thin archives for multi-y targets kbuild: kallsyms allow 3-pass generation if symbols size has changed
2016-12-11make use of make variable CURDIR instead of calling pwdUwe Kleine-König1-2/+2
make already provides the current working directory in a variable, so make use of it instead of forking a shell. Also replace usage of PWD by CURDIR. PWD is provided by most shells, but not all, so this makes the build system more robust. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Michal Marek <mmarek@suse.com>
2016-12-08bpf: xdp: Add XDP example for head adjustmentMartin KaFai Lau1-0/+4
The XDP prog checks if the incoming packet matches any VIP:PORT combination in the BPF hashmap. If it is, it will encapsulate the packet with a IPv4/v6 header as instructed by the value of the BPF hashmap and then XDP_TX it out. The VIP:PORT -> IP-Encap-Info can be specified by the cmd args of the user prog. Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03samples, bpf: Add automated test for cgroup filter attachmentsSargun Dhillon1-0/+2
This patch adds the sample program test_cgrp2_attach2. This program is similar to test_cgrp2_attach, but it performs automated testing of the cgroupv2 BPF attached filters. It runs the following checks: * Simple filter attachment * Application of filters to child cgroups * Overriding filters on child cgroups * Checking that this still works when the parent filter is removed The filters that are used here are simply allow all / deny all filters, so it isn't checking the actual functionality of the filters, but rather the behaviour around detachment / attachment. If net_cls is enabled, this test will fail. Signed-off-by: Sargun Dhillon <sargun@sargun.me> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03samples, bpf: Refactor test_current_task_under_cgroup - separate out helpersSargun Dhillon1-1/+1
This patch modifies test_current_task_under_cgroup_user. The test has several helpers around creating a temporary environment for cgroup testing, and moving the current task around cgroups. This set of helpers can then be used in other tests. Signed-off-by: Sargun Dhillon <sargun@sargun.me> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03samples/bpf: silence compiler warningsAlexei Starovoitov1-0/+2
silence some of the clang compiler warnings like: include/linux/fs.h:2693:9: warning: comparison of unsigned enum expression < 0 is always false arch/x86/include/asm/processor.h:491:30: warning: taking address of packed member 'sp0' of class or structure 'x86_hw_tss' may result in an unaligned pointer value include/linux/cgroup-defs.h:326:16: warning: field 'cgrp' with variable sized type 'struct cgroup' not at the end of a struct or class is a GNU extension since they add too much noise to samples/bpf/ build. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02samples/bpf: add userspace example for prohibiting socketsDavid Ahern1-0/+4
Add examples preventing a process in a cgroup from opening a socket based family, protocol and type. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02samples: bpf: add userspace example for modifying sk_bound_dev_ifDavid Ahern1-0/+2
Add a simple program to demonstrate the ability to attach a bpf program to a cgroup that sets sk_bound_dev_if for AF_INET{6} sockets when they are created. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02bpf: Add tests and samples for LWT-BPFThomas Graf1-0/+4
Adds a series of tests to verify the functionality of attaching BPF programs at LWT hooks. Also adds a sample which collects a histogram of packet sizes which pass through an LWT hook. $ ./lwt_len_hist.sh Starting netserver with host 'IN(6)ADDR_ANY' port '12865' and family AF_UNSPEC MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.253.2 () port 0 AF_INET : demo Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 39857.69 1 -> 1 : 0 | | 2 -> 3 : 0 | | 4 -> 7 : 0 | | 8 -> 15 : 0 | | 16 -> 31 : 0 | | 32 -> 63 : 22 | | 64 -> 127 : 98 | | 128 -> 255 : 213 | | 256 -> 511 : 1444251 |******** | 512 -> 1023 : 660610 |*** | 1024 -> 2047 : 535241 |** | 2048 -> 4095 : 19 | | 4096 -> 8191 : 180 | | 8192 -> 16383 : 5578023 |************************************* | 16384 -> 32767 : 632099 |*** | 32768 -> 65535 : 6575 | | Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-30samples/bpf: fix include pathAlexei Starovoitov1-1/+1
Fix the following build error: HOSTCC samples/bpf/test_lru_dist.o ../samples/bpf/test_lru_dist.c:25:22: fatal error: bpf_util.h: No such file or directory This is due to objtree != srctree. Use srctree, since that's where bpf_util.h is located. Fixes: e00c7b216f34 ("bpf: fix multiple issues in selftest suite and samples") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-27bpf: fix multiple issues in selftest suite and samplesDaniel Borkmann1-0/+1
1) The test_lru_map and test_lru_dist fails building on my machine since the sys/resource.h header is not included. 2) test_verifier fails in one test case where we try to call an invalid function, since the verifier log output changed wrt printing function names. 3) Current selftest suite code relies on sysconf(_SC_NPROCESSORS_CONF) for retrieving the number of possible CPUs. This is broken at least in our scenario and really just doesn't work. glibc tries a number of things for retrieving _SC_NPROCESSORS_CONF. First it tries equivalent of /sys/devices/system/cpu/cpu[0-9]* | wc -l, if that fails, depending on the config, it either tries to count CPUs in /proc/cpuinfo, or returns the _SC_NPROCESSORS_ONLN value instead. If /proc/cpuinfo has some issue, it returns just 1 worst case. This oddity is nothing new [1], but semantics/behaviour seems to be settled. _SC_NPROCESSORS_ONLN will parse /sys/devices/system/cpu/online, if that fails it looks into /proc/stat for cpuX entries, and if also that fails for some reason, /proc/cpuinfo is consulted (and returning 1 if unlikely all breaks down). While that might match num_possible_cpus() from the kernel in some cases, it's really not guaranteed with CPU hotplugging, and can result in a buffer overflow since the array in user space could have too few number of slots, and on perpcu map lookup, the kernel will write beyond that memory of the value buffer. William Tu reported such mismatches: [...] The fact that sysconf(_SC_NPROCESSORS_CONF) != num_possible_cpu() happens when CPU hotadd is enabled. For example, in Fusion when setting vcpu.hotadd = "TRUE" or in KVM, setting ./qemu-system-x86_64 -smp 2, maxcpus=4 ... the num_possible_cpu() will be 4 and sysconf() will be 2 [2]. [...] Documentation/cputopology.txt says /sys/devices/system/cpu/possible outputs cpu_possible_mask. That is the same as in num_possible_cpus(), so first step would be to fix the _SC_NPROCESSORS_CONF calls with our own implementation. Later, we could add support to bpf(2) for passing a mask via CPU_SET(3), for example, to just select a subset of CPUs. BPF samples code needs this fix as well (at least so that people stop copying this). Thus, define bpf_num_possible_cpus() once in selftests and import it from there for the sample code to avoid duplicating it. The remaining sysconf(_SC_NPROCESSORS_CONF) in samples are unrelated. After all three issues are fixed, the test suite runs fine again: # make run_tests | grep self selftests: test_verifier [PASS] selftests: test_maps [PASS] selftests: test_lru_map [PASS] selftests: test_kmod.sh [PASS] [1] https://www.sourceware.org/ml/libc-alpha/2011-06/msg00079.html [2] https://www.mail-archive.com/netdev@vger.kernel.org/msg121183.html Fixes: 3059303f59cf ("samples/bpf: update tracex[23] examples to use per-cpu maps") Fixes: 86af8b4191d2 ("Add sample for adding simple drop program to link") Fixes: df570f577231 ("samples/bpf: unit test for BPF_MAP_TYPE_PERCPU_ARRAY") Fixes: e15596717948 ("samples/bpf: unit test for BPF_MAP_TYPE_PERCPU_HASH") Fixes: ebb676daa1a3 ("bpf: Print function name in addition to function id") Fixes: 5db58faf989f ("bpf: Add tests for the LRU bpf_htab") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: William Tu <u9012063@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-25samples: bpf: add userspace example for attaching eBPF programs to cgroupsDaniel Mack1-0/+2
Add a simple userpace program to demonstrate the new API to attach eBPF programs to cgroups. This is what it does: * Create arraymap in kernel with 4 byte keys and 8 byte values * Load eBPF program The eBPF program accesses the map passed in to store two pieces of information. The number of invocations of the program, which maps to the number of packets received, is stored to key 0. Key 1 is incremented on each iteration by the number of bytes stored in the skb. * Detach any eBPF program previously attached to the cgroup * Attach the new program to the cgroup using BPF_PROG_ATTACH * Once a second, read map[0] and map[1] to see how many bytes and packets were seen on any socket of tasks in the given cgroup. The program takes a cgroup path as 1st argument, and either "ingress" or "egress" as 2nd. Optionally, "drop" can be passed as 3rd argument, which will make the generated eBPF program return 0 instead of 1, so the kernel will drop the packet. libbpf gained two new wrappers for the new syscall commands. Signed-off-by: Daniel Mack <daniel@zonque.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>