kernel/samples/bpf/tracex2_user.c, branch linux-5.10.y

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

2020-10-27T21:46:17Z

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

samples, bpf: Refactor kprobe tracing user progs with libbpf

2020-05-19T15:12:53Z

Currently, the kprobe BPF program attachment method for bpf_load is quite old. The implementation of bpf_load "directly" controls and manages(create, delete) the kprobe events of DEBUGFS. On the other hand, using using the libbpf automatically manages the kprobe event. (under bpf_link interface) By calling bpf_program__attach(_kprobe) in libbpf, the corresponding kprobe is created and the BPF program will be attached to this kprobe. To remove this, by simply invoking bpf_link__destroy will clean up the event. This commit refactors kprobe tracing programs (tracex{1~7}_user.c) with libbpf using bpf_link interface and bpf_program__attach. tracex2_kern.c, which tracks system calls (sys_*), has been modified to append prefix depending on architecture. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200516040608.1377876-3-danieltimlee@gmail.com

samples: bpf: force IPv4 in ping

2019-02-28T23:53:45Z

ping localhost may default of IPv6 on modern systems, but samples are trying to only parse IPv4. Force IPv4. samples/bpf/tracex1_user.c doesn't interpret the packet so we don't care which IP version will be used there. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Acked-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann

samples: bpf: include bpf/bpf.h instead of local libbpf.h

2018-05-15T05:52:10Z

There are two files in the tree called libbpf.h which is becoming problematic. Most samples don't actually need the local libbpf.h they simply include it to get to bpf/bpf.h. Include bpf/bpf.h directly instead. Signed-off-by: Jakub Kicinski Acked-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55Z

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 Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

samples/bpf: run cleanup routines when receiving SIGTERM

2017-05-12T01:43:30Z

Shahid Habib noticed that when xdp1 was killed from a different console the xdp program was not cleaned-up properly in the kernel and it continued to forward traffic. Most of the applications in samples/bpf cleanup properly, but only when getting SIGINT. Since kill defaults to using SIGTERM, add support to cleanup when the application receives either SIGINT or SIGTERM. Signed-off-by: Andy Gospodarek Reported-by: Shahid Habib Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller

samples/bpf: adjust rlimit RLIMIT_MEMLOCK for traceex2, tracex3 and tracex4

2017-05-03T13:30:23Z

Needed to adjust max locked memory RLIMIT_MEMLOCK for testing these bpf samples as these are using more and larger maps than can fit in distro default 64Kbytes limit. Signed-off-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller

samples/bpf: Make samples more libbpf-centric

2016-12-15T19:25:47Z

Switch all of the sample code to use the function names from tools/lib/bpf so that they're consistent with that, and to declare their own log buffers. This allow the next commit to be purely devoted to getting rid of the duplicate library in samples/bpf. Committer notes: Testing it: On a fedora rawhide container, with clang/llvm 3.9, sharing the host linux kernel git tree: # make O=/tmp/build/linux/ headers_install # make O=/tmp/build/linux -C samples/bpf/ Since I forgot to make it privileged, just tested it outside the container, using what it generated: # uname -a Linux jouet 4.9.0-rc8+ #1 SMP Mon Dec 12 11:20:49 BRT 2016 x86_64 x86_64 x86_64 GNU/Linux # cd /var/lib/docker/devicemapper/mnt/c43e09a53ff56c86a07baf79847f00e2cc2a17a1e2220e1adbf8cbc62734feda/rootfs/tmp/build/linux/samples/bpf/ # ls -la offwaketime -rwxr-xr-x. 1 root root 24200 Dec 15 12:19 offwaketime # 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]=c940d3f127d5e66cdd680e42d885cb0b64f8a0e4, not stripped # readelf -SW offwaketime_kern.o | grep PROGBITS [ 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 [ 5] tracepoint/sched/sched_switch PROGBITS 0000000000000000 000118 000318 00 AX 0 0 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 # ./offwaketime | head -5 swapper/1;start_secondary;cpu_startup_entry;schedule_preempt_disabled;schedule;__schedule;-;---;; 106 CPU 0/KVM;entry_SYSCALL_64_fastpath;sys_ioctl;do_vfs_ioctl;kvm_vcpu_ioctl;kvm_arch_vcpu_ioctl_run;kvm_vcpu_block;schedule;__schedule;-;try_to_wake_up;swake_up_locked;swake_up;apic_timer_expired;apic_timer_fn;__hrtimer_run_queues;hrtimer_interrupt;local_apic_timer_interrupt;smp_apic_timer_interrupt;__irqentry_text_start;cpuidle_enter;call_cpuidle;cpu_startup_entry;start_secondary;;swapper/3 2 Compositor;entry_SYSCALL_64_fastpath;sys_futex;do_futex;futex_wait;futex_wait_queue_me;schedule;__schedule;-;try_to_wake_up;futex_requeue;do_futex;sys_futex;entry_SYSCALL_64_fastpath;;SoftwareVsyncTh 5 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 13 JS Helper;entry_SYSCALL_64_fastpath;sys_futex;do_futex;futex_wait;futex_wait_queue_me;schedule;__schedule;-;try_to_wake_up;do_futex;sys_futex;entry_SYSCALL_64_fastpath;;firefox 2 # Signed-off-by: Joe Stringer Tested-by: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Wang Nan Cc: netdev@vger.kernel.org Link: http://lkml.kernel.org/r/20161214224342.12858-2-joe@ovn.org Signed-off-by: Arnaldo Carvalho de Melo

bpf: fix multiple issues in selftest suite and samples

2016-11-28T01:38:47Z

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 Cc: William Tu Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

samples/bpf: update tracex[23] examples to use per-cpu maps

2016-02-06T08:34:36Z

Signed-off-by: Alexei Starovoitov Signed-off-by: David S. Miller