aboutsummaryrefslogtreecommitdiff
path: root/tools/testing/selftests/bpf/Makefile
AgeCommit message (Collapse)AuthorFilesLines
2024-10-10selftests/bpf: Fix cross-compiling urandom_readTony Ambardar1-1/+1
Linking of urandom_read and liburandom_read.so prefers LLVM's 'ld.lld' but falls back to using 'ld' if unsupported. However, this fallback discards any existing makefile macro for LD and can break cross-compilation. Fix by changing the fallback to use the target linker $(LD), passed via '-fuse-ld=' using an absolute path rather than a linker "flavour". Fixes: 08c79c9cd67f ("selftests/bpf: Don't force lld on non-x86 architectures") Signed-off-by: Tony Ambardar <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-10-10selftests/bpf: Add test for kfunc module orderSimon Sundberg1-1/+19
Add a test case for kfuncs from multiple external modules, checking that the correct kfuncs are called regardless of which order they're called in. Specifically, check that calling the kfuncs in an order different from the one the modules' BTF are loaded in works. Signed-off-by: Simon Sundberg <[email protected]> Acked-by: Kumar Kartikeya Dwivedi <[email protected]> Signed-off-by: Toke Høiland-Jørgensen <[email protected]> Link: https://lore.kernel.org/r/20241010-fix-kfunc-btf-caching-for-modules-v2-3-745af6c1af98@redhat.com Signed-off-by: Alexei Starovoitov <[email protected]>
2024-09-11selftests/bpf: add build ID testsAndrii Nakryiko1-2/+3
Add a new set of tests validating behavior of capturing stack traces with build ID. We extend uprobe_multi target binary with ability to trigger uprobe (so that we can capture stack traces from it), but also we allow to force build ID data to be either resident or non-resident in memory (see also a comment about quirks of MADV_PAGEOUT). That way we can validate that in non-sleepable context we won't get build ID (as expected), but with sleepable uprobes we will get that build ID regardless of it being physically present in memory. Also, we add a small add-on linker script which reorders .note.gnu.build-id section and puts it after (big) .text section, putting build ID data outside of the very first page of ELF file. This will test all the relaxations we did in build ID parsing logic in kernel thanks to freader abstraction. Reviewed-by: Eduard Zingerman <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-09-05selftests/bpf: Prefer static linking for LLVM librariesEduard Zingerman1-5/+3
It is not always convenient to have LLVM libraries installed inside CI rootfs images, thus request static libraries from llvm-config. Suggested-by: Andrii Nakryiko <[email protected]> Signed-off-by: Eduard Zingerman <[email protected]> Acked-by: Daniel Borkmann <[email protected]> Tested-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-09-05selftests/bpf: Adapt OUTPUT appending logic to lower versions of MakePu Lehui1-0/+6
The $(let ...) function is only supported by GNU Make version 4.4 [0] and above, otherwise the following exception file or directory will be generated: tools/testing/selftests/bpfFEATURE-DUMP.selftests tools/testing/selftests/bpffeature/ Considering that the GNU Make version of most Linux distributions is lower than 4.4, let us adapt the corresponding logic to it. Link: https://lists.gnu.org/archive/html/info-gnu/2022-10/msg00008.html [0] Acked-by: Eduard Zingerman <[email protected]> Signed-off-by: Pu Lehui <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-08-30selftests/bpf: Do not update vmlinux.h unnecessarilyIhor Solodrai1-1/+5
%.bpf.o objects depend on vmlinux.h, which makes them transitively dependent on unnecessary libbpf headers. However vmlinux.h doesn't actually change as often. When generating vmlinux.h, compare it to a previous version and update it only if there are changes. Example of build time improvement (after first clean build): $ touch ../../../lib/bpf/bpf.h $ time make -j8 Before: real 1m37.592s After: real 0m27.310s Notice that %.bpf.o gen step is skipped if vmlinux.h hasn't changed. Signed-off-by: Ihor Solodrai <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/CAEf4BzY1z5cC7BKye8=A8aTVxpsCzD=p1jdTfKC7i0XVuYoHUQ@mail.gmail.com Link: https://lore.kernel.org/bpf/[email protected]
2024-08-30selftests/bpf: Specify libbpf headers required for %.bpf.o progsIhor Solodrai1-2/+7
Test %.bpf.o objects actually depend only on some libbpf headers. Define a list of required headers and use it as TRUNNER_BPF_OBJS dependency. bpf_*.h list was determined by: $ grep -rh 'include <bpf/bpf_' progs | sort -u Signed-off-by: Ihor Solodrai <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: Link: https://lore.kernel.org/bpf/[email protected] https://lore.kernel.org/bpf/CAEf4BzYQ-j2i_xjs94Nn=8+FVfkWt51mLZyiYKiz9oA4Z=pCeA@mail.gmail.com/
2024-08-23selftests/bpf: use simply-expanded variables for libpcap flagsEduard Zingerman1-3/+4
Save pkg-config output for libpcap as simply-expanded variables. For an obscure reason 'shell' call in LDLIBS/CFLAGS recursively expanded variables makes *.test.o files compilation non-parallel when make is executed with -j option. While at it, reuse 'pkg-config --cflags' call to define -DTRAFFIC_MONITOR=1 option, it's exit status is the same as for 'pkg-config --exists'. Fixes: f52403b6bfea ("selftests/bpf: Add traffic monitor functions.") Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-08-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfAlexei Starovoitov1-1/+1
Cross-merge bpf fixes after downstream PR including important fixes (from bpf-next point of view): commit 41c24102af7b ("selftests/bpf: Filter out _GNU_SOURCE when compiling test_cpp") commit fdad456cbcca ("bpf: Fix updating attached freplace prog in prog_array map") No conflicts. Adjacent changes in: include/linux/bpf_verifier.h kernel/bpf/verifier.c tools/testing/selftests/bpf/Makefile Link: https://lore.kernel.org/bpf/[email protected]/ Signed-off-by: Alexei Starovoitov <[email protected]>
2024-08-21selftests/bpf: utility function to get program disassembly after jitEduard Zingerman1-2/+46
This commit adds a utility function to get disassembled text for jited representation of a BPF program designated by file descriptor. Function prototype looks as follows: int get_jited_program_text(int fd, char *text, size_t text_sz) Where 'fd' is a file descriptor for the program, 'text' and 'text_sz' refer to a destination buffer for disassembled text. Output format looks as follows: 18: 77 06 ja L0 1a: 50 pushq %rax 1b: 48 89 e0 movq %rsp, %rax 1e: eb 01 jmp L1 20: 50 L0: pushq %rax 21: 50 L1: pushq %rax ^ ^^^^^^^^ ^ ^^^^^^^^^^^^^^^^^^ | binary insn | textual insn | representation | representation | | instruction offset inferred local label name The code and makefile changes are inspired by jit_disasm.c from bpftool. Use llvm libraries to disassemble BPF program instead of libbfd to avoid issues with disassembly output stability pointed out in [1]. Selftests makefile uses Makefile.feature to detect if LLVM libraries are available. If that is not the case selftests build proceeds but the function returns -EOPNOTSUPP at runtime. [1] commit eb9d1acf634b ("bpftool: Add LLVM as default library for disassembling JIT-ed programs") Acked-by: Yonghong Song <[email protected]> Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-08-19selftests/bpf: Disable strict aliasing for verifier_nocsr.cCupertino Miranda1-0/+1
verfifier_nocsr.c fails to compile in GCC. The reason behind it was initially explained in commit 27a90b14b93d3b2e1efd10764e456af7e2a42991. "A few BPF selftests perform type punning and they may break strict aliasing rules, which are exploited by both GCC and clang by default while optimizing. This can lead to broken compiled programs." Signed-off-by: Cupertino Miranda <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-08-15selftests/bpf: Add traffic monitor functions.Kui-Feng Lee1-0/+4
Add functions that capture packets and print log in the background. They are supposed to be used for debugging flaky network test cases. A monitored test case should call traffic_monitor_start() to start a thread to capture packets in the background for a given namespace and call traffic_monitor_stop() to stop capturing. (Or, option '-m' implemented by the later patches.) lo In IPv4 127.0.0.1:40265 > 127.0.0.1:55907: TCP, length 68, SYN lo In IPv4 127.0.0.1:55907 > 127.0.0.1:40265: TCP, length 60, SYN, ACK lo In IPv4 127.0.0.1:40265 > 127.0.0.1:55907: TCP, length 60, ACK lo In IPv4 127.0.0.1:55907 > 127.0.0.1:40265: TCP, length 52, ACK lo In IPv4 127.0.0.1:40265 > 127.0.0.1:55907: TCP, length 52, FIN, ACK lo In IPv4 127.0.0.1:55907 > 127.0.0.1:40265: TCP, length 52, RST, ACK Packet file: packets-2173-86-select_reuseport:sockhash_IPv4_TCP_LOOPBACK_test_detach_bpf-test.log #280/87 select_reuseport/sockhash IPv4/TCP LOOPBACK test_detach_bpf:OK The above is the output of an example. It shows the packets of a connection and the name of the file that contains captured packets in the directory /tmp/tmon_pcap. The file can be loaded by tcpdump or wireshark. This feature only works if libpcap is available. (Could be found by pkg-config) Acked-by: Stanislav Fomichev <[email protected]> Signed-off-by: Kui-Feng Lee <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-08-14selftests/bpf: convert test_skb_cgroup_id_user to test_progsAlexis Lothoré (eBPF Foundation)1-2/+1
test_skb_cgroup_id_user allows testing skb cgroup id retrieval at different levels, but is not integrated in test_progs, so it is not run automatically in CI. The test overlaps a bit with cgroup_skb_sk_lookup_kern, which is integrated in test_progs and test extensively skb cgroup helpers, but there is still one major difference between the two tests which justifies the conversion: cgroup_skb_sk_lookup_kern deals with a BPF_PROG_TYPE_CGROUP_SKB (attached on a cgroup), while test_skb_cgroup_id_user deals with a BPF_PROG_TYPE_SCHED_CLS (attached on a qdisc) Convert test_skb_cgroup_id_user into test_progs framework in order to run it automatically in CI. The main differences with the original test are the following: - rename the test to make it shorter and more straightforward regarding tested feature - the wrapping shell script has been dropped since every setup step is now handled in the main C test file - the test has been renamed for a shorter name and reflecting the tested API - add dedicated assert log per level to ease test failure debugging - use global variables instead of maps to access bpf prog data Signed-off-by: Alexis Lothoré (eBPF Foundation) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-08-14selftests/bpf: convert test_cgroup_storage to test_progsAlexis Lothoré (eBPF Foundation)1-2/+0
test_cgroup_storage is currently a standalone program which is not run when executing test_progs. Convert it to the test_progs framework so it can be automatically executed in CI. The conversion led to the following changes: - converted the raw bpf program in the userspace test file into a dedicated test program in progs/ dir - reduced the scope of cgroup_storage test: the content from this test overlaps with some other tests already present in test_progs, most notably netcnt and cgroup_storage_multi*. Those tests already check extensively local storage, per-cpu local storage, cgroups interaction, etc. So the new test only keep the part testing that the program return code (based on map content) properly leads to packet being passed or dropped. Reviewed-by: Alan Maguire <[email protected]> Signed-off-by: Alexis Lothoré (eBPF Foundation) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-08-14selftests/bpf: convert get_current_cgroup_id_user to test_progsAlexis Lothoré (eBPF Foundation)1-2/+1
get_current_cgroup_id_user allows testing for bpf_get_current_cgroup_id() bpf API but is not integrated into test_progs, and so is not tested automatically in CI. Convert it to the test_progs framework to allow running it automatically. The most notable differences with the old test are the following: - the new test relies on autoattach instead of manually hooking/enabling the targeted tracepoint through perf_event, which reduces quite a lot the test code size - it also accesses bpf prog data through global variables instead of maps - sleep duration passed to nanosleep syscall has been reduced to its minimum to not impact overall CI duration (we only care about the syscall being properly triggered, not about the passed duration) Signed-off-by: Alexis Lothoré (eBPF Foundation) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-07-31selftests/bpf: convert test_dev_cgroup to test_progsAlexis Lothoré (eBPF Foundation)1-2/+0
test_dev_cgroup is defined as a standalone test program, and so is not executed in CI. Convert it to test_progs framework so it is tested automatically in CI, and remove the old test. In order to be able to run it in test_progs, /dev/null must remain usable, so change the new test to test operations on devices 1:3 as valid, and operations on devices 1:5 (/dev/zero) as invalid. Reviewed-by: Alan Maguire <[email protected]> Acked-by: Stanislav Fomichev <[email protected]> Signed-off-by: Alexis Lothoré (eBPF Foundation) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-07-29selftests/bpf: Integrate test_xdp_veth into test_progsAlexis Lothoré (eBPF Foundation)1-1/+0
test_xdp_veth.sh tests that XDP return codes work as expected, by bringing up multiple veth pairs isolated in different namespaces, attaching specific xdp programs to each interface, and ensuring that the whole chain allows to ping one end interface from the first one. The test runs well but is currently not integrated in test_progs, which prevents it from being run automatically in the CI infrastructure. Rewrite it as a C test relying on libbpf to allow running it in the CI infrastructure. The new code brings up the same network infrastructure and reuses the same eBPF programs as test_xdp_veth.sh, for which skeletons are already generated by the bpf tests makefile. Signed-off-by: Alexis Lothoré (eBPF Foundation) <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Stanislav Fomichev <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Make %.test.d prerequisite order onlyIhor Solodrai1-1/+1
%.test.o should depend on %.test.d order-only to avoid unnecessary recompilations due to compiler dumping .d and .o files in random order. Signed-off-by: Ihor Solodrai <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/all/gSoCpn9qV5K0hRvrvYlrw2StRntsvZcrUuDfkZUh1Ang9E6yZ9XJGYDuIP9iCuM2YTVhSEzEXCteQ94_0uIUjx_mXwupFJt64NJaiMr99a0=@pm.me Link: https://lore.kernel.org/all/FnnOUuDMmf0SebqA1bb0fQIW4vguOZ-VcAlPnPMnmT2lJYxMMxFAhcgh77px8MsPS5Fr01I0YQxLJClEJTFWHdpaTBVSQhlmsVTcEsNQbV4=@pm.me Link: https://lore.kernel.org/bpf/yyjJRl5LODbI4-FseU0wIP5e4ik0zAy7Sy-5eGwrzG_UanI8rwWlQPfXAFnn_27hoZFogoUHRSWxFsLk7hPr0b6P5TZ3cRrM30_ggnu555M=@pm.me
2024-07-29selftests/bpf: extract utility function for BPF disassemblyEduard Zingerman1-0/+1
struct bpf_insn *disasm_insn(struct bpf_insn *insn, char *buf, size_t buf_sz); Disassembles instruction 'insn' to a text buffer 'buf'. Removes insn->code hex prefix added by kernel disassembly routine. Returns a pointer to the next instruction (increments insn by either 1 or 2). Acked-by: Andrii Nakryiko <[email protected]> Signed-off-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]>
2024-07-29selftests/bpf: Fix wrong binary in Makefile log outputTony Ambardar1-5/+6
Make log output incorrectly shows 'test_maps' as the binary name for every 'CLNG-BPF' build step, apparently picking up the last value defined for the $(TRUNNER_BINARY) variable. Update the 'CLANG_BPF_BUILD_RULE' variants to fix this confusing output. Current output: CLNG-BPF [test_maps] access_map_in_map.bpf.o GEN-SKEL [test_progs] access_map_in_map.skel.h ... CLNG-BPF [test_maps] access_map_in_map.bpf.o GEN-SKEL [test_progs-no_alu32] access_map_in_map.skel.h ... CLNG-BPF [test_maps] access_map_in_map.bpf.o GEN-SKEL [test_progs-cpuv4] access_map_in_map.skel.h After fix: CLNG-BPF [test_progs] access_map_in_map.bpf.o GEN-SKEL [test_progs] access_map_in_map.skel.h ... CLNG-BPF [test_progs-no_alu32] access_map_in_map.bpf.o GEN-SKEL [test_progs-no_alu32] access_map_in_map.skel.h ... CLNG-BPF [test_progs-cpuv4] access_map_in_map.bpf.o GEN-SKEL [test_progs-cpuv4] access_map_in_map.skel.h Fixes: a5d0c26a2784 ("selftests/bpf: Add a cpuv4 test runner for cpu=v4 testing") Fixes: 89ad7420b25c ("selftests/bpf: Drop the need for LLVM's llc") Signed-off-by: Tony Ambardar <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Acked-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-07-29selftests/bpf: Fix error linking uprobe_multi on mipsTony Ambardar1-0/+2
Linking uprobe_multi.c on mips64el fails due to relocation overflows, when the GOT entries required exceeds the default maximum. Add a specific CFLAGS (-mxgot) for uprobe_multi.c on MIPS that allows using a larger GOT and avoids errors such as: /tmp/ccBTNQzv.o: in function `bench': uprobe_multi.c:49:(.text+0x1d7720): relocation truncated to fit: R_MIPS_GOT_DISP against `uprobe_multi_func_08188' uprobe_multi.c:49:(.text+0x1d7730): relocation truncated to fit: R_MIPS_GOT_DISP against `uprobe_multi_func_08189' ... collect2: error: ld returned 1 exit status Fixes: 519dfeaf5119 ("selftests/bpf: Add uprobe_multi test program") Signed-off-by: Tony Ambardar <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/14eb7b70f8ccef9834874d75eb373cb9292129da.1721692479.git.tony.ambardar@gmail.com
2024-07-29selftests/bpf: Add missing system defines for mipsTony Ambardar1-1/+2
Update get_sys_includes in Makefile with missing MIPS-related definitions to fix many, many compilation errors building selftests/bpf. The following added defines drive conditional logic in system headers for word-size and endianness selection: MIPSEL, MIPSEB _MIPS_SZPTR _MIPS_SZLONG _MIPS_SIM, _ABIO32, _ABIN32, _ABI64 Signed-off-by: Tony Ambardar <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/f3cfceaf5299cdd2ac0e0a36072d6ca7be23e603.1721692479.git.tony.ambardar@gmail.com
2024-07-29selftests/bpf: Don't include .d files on make cleanIhor Solodrai1-0/+2
Ignore generated %.test.o dependencies when make goal is clean or docs-clean. Signed-off-by: Ihor Solodrai <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/all/oNTIdax7aWGJdEgabzTqHzF4r-WTERrV1e1cNaPQMp-UhYUQpozXqkbuAlLBulczr6I99-jM5x3dxv56JJowaYBkm765R9Aa9kyrVuCl_kA=@pm.me Link: https://lore.kernel.org/bpf/K69Y8OKMLXBWR0dtOfsC4J46-HxeQfvqoFx1CysCm7u19HRx4MB6yAKOFkM6X-KAx2EFuCcCh_9vYWpsgQXnAer8oQ8PMeDEuiRMYECuGH4=@pm.me
2024-07-29selftests/bpf: Filter out _GNU_SOURCE when compiling test_cppStanislav Fomichev1-1/+1
Jakub reports build failures when merging linux/master with net tree: CXX test_cpp In file included from <built-in>:454: <command line>:2:9: error: '_GNU_SOURCE' macro redefined [-Werror,-Wmacro-redefined] 2 | #define _GNU_SOURCE | ^ <built-in>:445:9: note: previous definition is here 445 | #define _GNU_SOURCE 1 The culprit is commit cc937dad85ae ("selftests: centralize -D_GNU_SOURCE= to CFLAGS in lib.mk") which unconditionally added -D_GNU_SOUCE to CLFAGS. Apparently clang++ also unconditionally adds it for the C++ targets [0] which causes a conflict. Add small change in the selftests makefile to filter it out for test_cpp. Not sure which tree it should go via, targeting bpf for now, but net might be better? 0: https://stackoverflow.com/questions/11670581/why-is-gnu-source-defined-by-default-and-how-to-turn-it-off Signed-off-by: Stanislav Fomichev <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Acked-by: Jiri Olsa <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-07-29selftests/bpf: Use auto-dependencies for test objectsIhor Solodrai1-11/+32
Make use of -M compiler options when building .test.o objects to generate .d files and avoid re-building all tests every time. Previously, if a single test bpf program under selftests/bpf/progs/*.c has changed, make would rebuild all the *.bpf.o, *.skel.h and *.test.o objects, which is a lot of unnecessary work. A typical dependency chain is: progs/x.c -> x.bpf.o -> x.skel.h -> x.test.o -> trunner_binary However for many tests it's not a 1:1 mapping by name, and so far %.test.o have been simply dependent on all %.skel.h files, and %.skel.h files on all %.bpf.o objects. Avoid full rebuilds by instructing the compiler (via -MMD) to produce *.d files with real dependencies, and appropriately including them. Exploit make feature that rebuilds included makefiles if they were changed by setting %.test.d as prerequisite for %.test.o files. A couple of examples of compilation time speedup (after the first clean build): $ touch progs/verifier_and.c && time make -j8 Before: real 0m16.651s After: real 0m2.245s $ touch progs/read_vsyscall.c && time make -j8 Before: real 0m15.743s After: real 0m1.575s A drawback of this change is that now there is an overhead due to make processing lots of .d files, which potentially may slow down unrelated targets. However a time to make all from scratch hasn't changed significantly: $ make clean && time make -j8 Before: real 1m31.148s After: real 1m30.309s Suggested-by: Eduard Zingerman <[email protected]> Signed-off-by: Ihor Solodrai <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/VJihUTnvtwEgv_mOnpfy7EgD9D2MPNoHO-MlANeLIzLJPGhDeyOuGKIYyKgk0O6KPjfM-MuhtvPwZcngN8WFqbTnTRyCSMc2aMZ1ODm1T_g=@pm.me
2024-06-24selftests/bpf: Add more ring buffer test coverageDaniel Borkmann1-1/+1
Add test coverage for reservations beyond the ring buffer size in order to validate that bpf_ringbuf_reserve() rejects the request with NULL, all other ring buffer tests keep passing as well: # ./vmtest.sh -- ./test_progs -t ringbuf [...] ./test_progs -t ringbuf [ 1.165434] bpf_testmod: loading out-of-tree module taints kernel. [ 1.165825] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel [ 1.284001] tsc: Refined TSC clocksource calibration: 3407.982 MHz [ 1.286871] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x311fc34e357, max_idle_ns: 440795379773 ns [ 1.289555] clocksource: Switched to clocksource tsc #274/1 ringbuf/ringbuf:OK #274/2 ringbuf/ringbuf_n:OK #274/3 ringbuf/ringbuf_map_key:OK #274/4 ringbuf/ringbuf_write:OK #274 ringbuf:OK #275 ringbuf_multi:OK [...] Signed-off-by: Daniel Borkmann <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> [ Test fixups for getting BPF CI back to work ] Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-05-12bpf: disable strict aliasing in test_global_func9.cJose E. Marchesi1-0/+1
The BPF selftest test_global_func9.c performs type punning and breaks srict-aliasing rules. In particular, given: int global_func9(struct __sk_buff *skb) { int result = 0; [...] { const struct C c = {.x = skb->len, .y = skb->family }; result |= foo((const struct S *)&c); } } When building with strict-aliasing enabled (the default) the initialization of `c' gets optimized away in its entirely: [... no initialization of `c' ...] r1 = r10 r1 += -40 call foo w0 |= w6 Since GCC knows that `foo' accesses s->x, we get a "maybe uninitialized" warning. On the other hand, when strict-aliasing is disabled GCC only optimizes away the store to `.y': r1 = *(u32 *) (r6+0) *(u32 *) (r10+-40) = r1 ; This is .x = skb->len in `c' r1 = r10 r1 += -40 call foo w0 |= w6 In this case the warning is not emitted, because s-> is initialized. This patch disables strict aliasing in this test when building with GCC. clang seems to not optimize this particular code even when strict aliasing is enabled. Tested in bpf-next master. Signed-off-by: Jose E. Marchesi <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Yonghong Song <[email protected]> Cc: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-05-12selftests/bpf: Retire test_sock_addr.(c|sh)Jordan Rife1-3/+1
Fully remove test_sock_addr.c and test_sock_addr.sh, as test coverage has been fully moved to prog_tests/sock_addr.c. Signed-off-by: Jordan Rife <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-05-09selftests/bpf: Use start_server_addr in test_tcp_check_syncookieGeliang Tang1-0/+1
Include network_helpers.h in test_tcp_check_syncookie_user.c, use public helper start_server_addr() in it instead of the local defined function start_server(). This can avoid duplicate code. Add two helpers v6only_true() and v6only_false() to set IPV6_V6ONLY sockopt to true or false, set them to post_socket_cb pointer of struct network_helper_opts, and pass it to start_server_setsockopt(). In order to use functions defined in network_helpers.c, Makefile needs to be updated too. Signed-off-by: Geliang Tang <[email protected]> Link: https://lore.kernel.org/r/e0c5324f5da84f453f47543536e70f126eaa8678.1714907662.git.tanggeliang@kylinos.cn Signed-off-by: Martin KaFai Lau <[email protected]>
2024-05-08bpf: avoid UB in usages of the __imm_insn macroJose E. Marchesi1-0/+13
[Changes from V2: - no-strict-aliasing is only applied when building with GCC. - cpumask_failure.c is excluded, as it doesn't use __imm_insn.] The __imm_insn macro is defined in bpf_misc.h as: #define __imm_insn(name, expr) [name]"i"(*(long *)&(expr)) This may lead to type-punning and strict aliasing rules violations in it's typical usage where the address of a struct bpf_insn is passed as expr, like in: __imm_insn(st_mem, BPF_ST_MEM(BPF_W, BPF_REG_1, offsetof(struct __sk_buff, mark), 42)) Where: #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ ((struct bpf_insn) { \ .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ .dst_reg = DST, \ .src_reg = 0, \ .off = OFF, \ .imm = IMM }) In all the actual instances of this in the BPF selftests the value is fed to a volatile asm statement as soon as it gets read from memory, and thus it is unlikely anti-aliasing rules breakage may lead to misguided optimizations. However, GCC detects the potential problem (indirectly) by issuing a warning stating that a temporary <Uxxxxxx> is used uninitialized, where the temporary corresponds to the memory read by *(long *). This patch adds -fno-strict-aliasing to the compilation flags of the particular selftests that do type punning via __imm_insn, only for GCC. Tested in master bpf-next. No regressions. Signed-off-by: Jose E. Marchesi <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Yonghong Song <[email protected]> Cc: Eduard Zingerman <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-05-07selftests/bpf: Add CFLAGS per source file and runnerCupertino Miranda1-8/+9
This patch adds support to specify CFLAGS per source file and per test runner. Signed-off-by: Cupertino Miranda <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-05-07bpf: Temporarily define BPF_NO_PRESEVE_ACCESS_INDEX for GCCJose E. Marchesi1-1/+1
The vmlinux.h file generated by bpftool makes use of compiler pragmas in order to install the CO-RE preserve_access_index in all the struct types derived from the BTF info: #ifndef __VMLINUX_H__ #define __VMLINUX_H__ #ifndef BPF_NO_PRESERVE_ACCESS_INDEX #pragma clang attribute push (__attribute__((preserve_access_index)), apply_t = record #endif [... type definitions generated from kernel BTF ... ] #ifndef BPF_NO_PRESERVE_ACCESS_INDEX #pragma clang attribute pop #endif The `clang attribute push/pop' pragmas are specific to clang/llvm and are not supported by GCC. At the moment the BTF dumping services in libbpf do not support dicriminating between types dumped because they are directly referred and types dumped because they are dependencies. A suitable API is being worked now. See [1] and [2]. In the interim, this patch changes the selftests/bpf Makefile so it passes -DBPF_NO_PRESERVE_ACCESS_INDEX to GCC when it builds the selftests. This workaround is temporary, and may have an impact on the results of the GCC-built tests. [1] https://lore.kernel.org/bpf/[email protected]/T/#u [2] https://lore.kernel.org/bpf/[email protected]/T/#u Tested in bpf-next master. No regressions. Signed-off-by: Jose E. Marchesi <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-05-07bpf: Disable some `attribute ignored' warnings in GCCJose E. Marchesi1-1/+1
This patch modifies selftests/bpf/Makefile to pass -Wno-attributes to GCC. This is because of the following attributes which are ignored: - btf_decl_tag - btf_type_tag There are many of these. At the moment none of these are recognized/handled by gcc-bpf. We are aware that btf_decl_tag is necessary for some of the selftest harness to communicate test failure/success. Support for it is in progress in GCC upstream: https://gcc.gnu.org/pipermail/gcc-patches/2024-May/650482.html However, the GCC master branch is not yet open, so the series above (currently under review upstream) wont be able to make it there until 14.1 gets released, probably mid next week. As for btf_type_tag, more extensive work will be needed in GCC upstream to support it in both BTF and DWARF. We have a WIP big patch for that, but that is not needed to compile/build the selftests. - used There are SEC macros defined in the selftests as: #define SEC(N) __attribute__((section(N),used)) The SEC macro is used for both functions and global variables. According to the GCC documentation `used' attribute is really only meaningful for functions, and it warns when the attribute is used for other global objects, like for example ctl_array in test_xdp_noinline.c. Ignoring this is benign. - align_value In progs/test_cls_redirect.c:127 there is: typedef uint8_t *net_ptr __attribute__((align_value(8))); GCC warns that it is ignoring this attribute, because it is not implemented by GCC. I think ignoring this attribute in GCC is benign, because according to the clang documentation [1] its purpose seems to be merely declarative and doesn't seem to translate into extra checks at run-time, only to perhaps better optimized code ("runtime behavior is undefined if the pointed memory object is not aligned to the specified alignment"). [1] https://clang.llvm.org/docs/AttributeReference.html#align-value Tested in bpf-next master. Signed-off-by: Jose E. Marchesi <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Acked-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-05-02bpf: Missing trailing slash in tools/testing/selftests/bpf/MakefileJose E. Marchesi1-1/+1
tools/lib/bpf/Makefile assumes that the patch in OUTPUT is a directory and that it includes a trailing slash. This seems to be a common expectation for OUTPUT among all the Makefiles. In the rule for runqslower in tools/testing/selftests/bpf/Makefile the variable BPFTOOL_OUTPUT is set to a directory name that lacks a trailing slash. This results in a malformed BPF_HELPER_DEFS being defined in lib/bpf/Makefile. This problem becomes evident when a file like tools/lib/bpf/bpf_tracing.h gets updated. This patch fixes the problem by adding the missing slash in the value for BPFTOOL_OUTPUT in the $(OUTPUT)/runqslower rule. Regtested by running selftests in bpf-next master and building samples/bpf programs. Signed-off-by: Jose E. Marchesi <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-04-29Merge tag 'for-netdev' of ↵Jakub Kicinski1-5/+8
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2024-04-29 We've added 147 non-merge commits during the last 32 day(s) which contain a total of 158 files changed, 9400 insertions(+), 2213 deletions(-). The main changes are: 1) Add an internal-only BPF per-CPU instruction for resolving per-CPU memory addresses and implement support in x86 BPF JIT. This allows inlining per-CPU array and hashmap lookups and the bpf_get_smp_processor_id() helper, from Andrii Nakryiko. 2) Add BPF link support for sk_msg and sk_skb programs, from Yonghong Song. 3) Optimize x86 BPF JIT's emit_mov_imm64, and add support for various atomics in bpf_arena which can be JITed as a single x86 instruction, from Alexei Starovoitov. 4) Add support for passing mark with bpf_fib_lookup helper, from Anton Protopopov. 5) Add a new bpf_wq API for deferring events and refactor sleepable bpf_timer code to keep common code where possible, from Benjamin Tissoires. 6) Fix BPF_PROG_TEST_RUN infra with regards to bpf_dummy_struct_ops programs to check when NULL is passed for non-NULLable parameters, from Eduard Zingerman. 7) Harden the BPF verifier's and/or/xor value tracking, from Harishankar Vishwanathan. 8) Introduce crypto kfuncs to make BPF programs able to utilize the kernel crypto subsystem, from Vadim Fedorenko. 9) Various improvements to the BPF instruction set standardization doc, from Dave Thaler. 10) Extend libbpf APIs to partially consume items from the BPF ringbuffer, from Andrea Righi. 11) Bigger batch of BPF selftests refactoring to use common network helpers and to drop duplicate code, from Geliang Tang. 12) Support bpf_tail_call_static() helper for BPF programs with GCC 13, from Jose E. Marchesi. 13) Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF program to have code sections where preemption is disabled, from Kumar Kartikeya Dwivedi. 14) Allow invoking BPF kfuncs from BPF_PROG_TYPE_SYSCALL programs, from David Vernet. 15) Extend the BPF verifier to allow different input maps for a given bpf_for_each_map_elem() helper call in a BPF program, from Philo Lu. 16) Add support for PROBE_MEM32 and bpf_addr_space_cast instructions for riscv64 and arm64 JITs to enable BPF Arena, from Puranjay Mohan. 17) Shut up a false-positive KMSAN splat in interpreter mode by unpoison the stack memory, from Martin KaFai Lau. 18) Improve xsk selftest coverage with new tests on maximum and minimum hardware ring size configurations, from Tushar Vyavahare. 19) Various ReST man pages fixes as well as documentation and bash completion improvements for bpftool, from Rameez Rehman & Quentin Monnet. 20) Fix libbpf with regards to dumping subsequent char arrays, from Quentin Deslandes. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (147 commits) bpf, docs: Clarify PC use in instruction-set.rst bpf_helpers.h: Define bpf_tail_call_static when building with GCC bpf, docs: Add introduction for use in the ISA Internet Draft selftests/bpf: extend BPF_SOCK_OPS_RTT_CB test for srtt and mrtt_us bpf: add mrtt and srtt as BPF_SOCK_OPS_RTT_CB args selftests/bpf: dummy_st_ops should reject 0 for non-nullable params bpf: check bpf_dummy_struct_ops program params for test runs selftests/bpf: do not pass NULL for non-nullable params in dummy_st_ops selftests/bpf: adjust dummy_st_ops_success to detect additional error bpf: mark bpf_dummy_struct_ops.test_1 parameter as nullable selftests/bpf: Add ring_buffer__consume_n test. bpf: Add bpf_guard_preempt() convenience macro selftests: bpf: crypto: add benchmark for crypto functions selftests: bpf: crypto skcipher algo selftests bpf: crypto: add skcipher to bpf crypto bpf: make common crypto API for TC/XDP programs bpf: update the comment for BTF_FIELDS_MAX selftests/bpf: Fix wq test. selftests/bpf: Use make_sockaddr in test_sock_addr selftests/bpf: Use connect_to_addr in test_sock_addr ... ==================== Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
2024-04-25selftests/bpf: Add ring_buffer__consume_n test.Andrea Righi1-1/+1
Add a testcase for the ring_buffer__consume_n() API. The test produces multiple samples in a ring buffer, using a sys_getpid() fentry prog, and consumes them from user-space in batches, rather than consuming all of them greedily, like ring_buffer__consume() does. Signed-off-by: Andrea Righi <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Acked-by: Jiri Olsa <[email protected]> Link: https://lore.kernel.org/lkml/CAEf4BzaR4zqUpDmj44KNLdpJ=Tpa97GrvzuzVNO5nM6b7oWd1w@mail.gmail.com Link: https://lore.kernel.org/bpf/[email protected]
2024-04-24selftests: bpf: crypto: add benchmark for crypto functionsVadim Fedorenko1-0/+2
Some simple benchmarks are added to understand the baseline of performance. Signed-off-by: Vadim Fedorenko <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-04-24selftests/bpf: Use start_server_addr in test_sock_addrGeliang Tang1-1/+2
Include network_helpers.h in test_sock_addr.c, use the newly added public helper start_server_addr() instead of the local defined function start_server(). This can avoid duplicate code. In order to use functions defined in network_helpers.c in test_sock_addr.c, Makefile needs to be updated and <Linux/err.h> needs to be included in network_helpers.h to avoid compilation errors. Signed-off-by: Geliang Tang <[email protected]> Link: https://lore.kernel.org/r/3101f57bde5502383eb41723c8956cc26be06893.1713868264.git.tanggeliang@kylinos.cn Signed-off-by: Martin KaFai Lau <[email protected]>
2024-04-17selftests: adopt BPF's approach to quieter buildsJakub Kicinski1-12/+1
selftest build is fairly noisy, it's easy to miss warnings. It's standard practice to add alternative messages in the Makefile. I was grepping for existing solutions, and found that bpf already has the right knobs. Move them to lib.mk and adopt in net. Convert the basic rules in lib.mk. Acked-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
2024-04-10selftests/bpf: Enable tests for atomics with cpuv4Yonghong Song1-1/+1
When looking at Alexei's patch ([1]) which added tests for atomics, I noticed that the tests will be skipped with cpuv4. For example, with latest llvm19, I see: [root@arch-fb-vm1 bpf]# ./test_progs -t arena_atomics #3/1 arena_atomics/add:OK ... #3/7 arena_atomics/xchg:OK #3 arena_atomics:OK Summary: 1/7 PASSED, 0 SKIPPED, 0 FAILED [root@arch-fb-vm1 bpf]# ./test_progs-cpuv4 -t arena_atomics #3 arena_atomics:SKIP Summary: 1/0 PASSED, 1 SKIPPED, 0 FAILED [root@arch-fb-vm1 bpf]# It is perfectly fine to enable atomics-related tests for cpuv4. With this patch, I have [root@arch-fb-vm1 bpf]# ./test_progs-cpuv4 -t arena_atomics #3/1 arena_atomics/add:OK ... #3/7 arena_atomics/xchg:OK #3 arena_atomics:OK Summary: 1/7 PASSED, 0 SKIPPED, 0 FAILED [1] https://lore.kernel.org/r/[email protected] Signed-off-by: Yonghong Song <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-04-10selftests: move bpf-offload test from bpf to netJakub Kicinski1-1/+0
We're building more python tests on the netdev side, and some of the classes from the venerable BPF offload tests can be reused. Acked-by: Stanislav Fomichev <[email protected]> Acked-by: Martin KaFai Lau <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
2024-04-03selftests/xsk: Introduce set_ring_size function with a retry mechanism for ↵Tushar Vyavahare1-1/+1
handling AF_XDP socket closures Introduce a new function, set_ring_size(), to manage asynchronous AF_XDP socket closure. Retry set_hw_ring_size up to SOCK_RECONF_CTR times if it fails due to an active AF_XDP socket. Return an error immediately for non-EBUSY errors. This enhances robustness against asynchronous AF_XDP socket closures during ring size changes. Signed-off-by: Tushar Vyavahare <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Magnus Karlsson <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-03-29selftests/bpf: make multi-uprobe tests work in RELEASE=1 modeAndrii Nakryiko1-1/+1
When BPF selftests are built in RELEASE=1 mode with -O2 optimization level, uprobe_multi binary, called from multi-uprobe tests is optimized to the point that all the thousands of target uprobe_multi_func_XXX functions are eliminated, breaking tests. So ensure they are preserved by using weak attribute. But, actually, compiling uprobe_multi binary with -O2 takes a really long time, and is quite useless (it's not a benchmark). So in addition to ensuring that uprobe_multi_func_XXX functions are preserved, opt-out of -O2 explicitly in Makefile and stick to -O0. This saves a lot of compilation time. With -O2, just recompiling uprobe_multi: $ touch uprobe_multi.c $ time make RELEASE=1 -j90 make RELEASE=1 -j90 291.66s user 2.54s system 99% cpu 4:55.52 total With -O0: $ touch uprobe_multi.c $ time make RELEASE=1 -j90 make RELEASE=1 -j90 22.40s user 1.91s system 99% cpu 24.355 total 5 minutes vs (still slow, but...) 24 seconds. Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2024-03-04selftests/bpf: Extend uprobe/uretprobe triggering benchmarksAndrii Nakryiko1-1/+1
Settle on three "flavors" of uprobe/uretprobe, installed on different kinds of instruction: nop, push, and ret. All three are testing different internal code paths emulating or single-stepping instructions, so are interesting to compare and benchmark separately. To ensure `push rbp` instruction we ensure that uprobe_target_push() is not a leaf function by calling (global __weak) noop function and returning something afterwards (if we don't do that, compiler will just do a tail call optimization). Also, we need to make sure that compiler isn't skipping frame pointer generation, so let's add `-fno-omit-frame-pointers` to Makefile. Just to give an idea of where we currently stand in terms of relative performance of different uprobe/uretprobe cases vs a cheap syscall (getpgid()) baseline, here are results from my local machine: $ benchs/run_bench_uprobes.sh base : 1.561 ± 0.020M/s uprobe-nop : 0.947 ± 0.007M/s uprobe-push : 0.951 ± 0.004M/s uprobe-ret : 0.443 ± 0.007M/s uretprobe-nop : 0.471 ± 0.013M/s uretprobe-push : 0.483 ± 0.004M/s uretprobe-ret : 0.306 ± 0.007M/s Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-02-22selftests/bpf: Test case for lacking CFI stub functions.Kui-Feng Lee1-1/+9
Ensure struct_ops rejects the registration of struct_ops types without proper CFI stub functions. bpf_test_no_cfi.ko is a module that attempts to register a struct_ops type called "bpf_test_no_cfi_ops" with cfi_stubs of NULL and non-NULL value. The NULL one should fail, and the non-NULL one should succeed. The module can only be loaded successfully if these registrations yield the expected results. Signed-off-by: Kui-Feng Lee <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Martin KaFai Lau <[email protected]>
2024-02-21selftests/bpf: Remove intermediate test files.Alexei Starovoitov1-0/+3
The test of linking process creates several intermediate files. Remove them once the build is over. This reduces the number of files in selftests/bpf/ directory from ~4400 to ~2600. Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-02-16selftests/bpf: Remove empty TEST_CUSTOM_PROGSMarcos Paulo de Souza1-3/+2
Commit f04a32b2c5b5 ("selftests/bpf: Do not use sign-file as testcase") removed the TEST_CUSTOM_PROGS assignment, and removed it from being used on TEST_GEN_FILES. Remove two leftovers from that cleanup. Found by inspection. Signed-off-by: Marcos Paulo de Souza <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Cc: Alexey Gladkov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-01-30bpf: Move -Wno-compare-distinct-pointer-types to BPF_CFLAGSJose E. Marchesi1-3/+3
Clang supports enabling/disabling certain conversion diagnostics via the -W[no-]compare-distinct-pointer-types command line options. Disabling this warning is required by some BPF selftests due to -Werror. Until very recently GCC would emit these warnings unconditionally, which was a problem for gcc-bpf, but we added support for the command-line options to GCC upstream [1]. This patch moves the -Wno-cmopare-distinct-pointer-types from CLANG_CFLAGS to BPF_CFLAGS in selftests/bpf/Makefile so the option is also used in gcc-bpf builds, not just in clang builds. Tested in bpf-next master. No regressions. [1] https://gcc.gnu.org/pipermail/gcc-patches/2023-August/627769.html Signed-off-by: Jose E. Marchesi <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2024-01-30bpf: Build type-punning BPF selftests with -fno-strict-aliasingJose E. Marchesi1-0/+13
A few BPF selftests perform type punning and they may break strict aliasing rules, which are exploited by both GCC and clang by default while optimizing. This can lead to broken compiled programs. This patch disables strict aliasing for these particular tests, by mean of the -fno-strict-aliasing command line option. This will make sure these tests are optimized properly even if some strict aliasing rule gets violated. After this patch, GCC is able to build all the selftests without warning about potential strict aliasing issue. bpf@vger discussion on strict aliasing and BPF selftests: https://lore.kernel.org/bpf/[email protected]/T/#t Tested in bpf-next master. No regressions. Signed-off-by: Jose E. Marchesi <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Link: https://lore.kernel.org/bpf/[email protected]
2024-01-29bpf: Use -Wno-error in certain tests when building with GCCJose E. Marchesi1-1/+11
Certain BPF selftests contain code that, albeit being legal C, trigger warnings in GCC that cannot be disabled. This is the case for example for the tests progs/btf_dump_test_case_bitfields.c progs/btf_dump_test_case_namespacing.c progs/btf_dump_test_case_packing.c progs/btf_dump_test_case_padding.c progs/btf_dump_test_case_syntax.c which contain struct type declarations inside function parameter lists. This is problematic, because: - The BPF selftests are built with -Werror. - The Clang and GCC compilers sometimes differ when it comes to handle warnings. in the handling of warnings. One compiler may emit warnings for code that the other compiles compiles silently, and one compiler may offer the possibility to disable certain warnings, while the other doesn't. In order to overcome this problem, this patch modifies the tools/testing/selftests/bpf/Makefile in order to: 1. Enable the possibility of specifing per-source-file extra CFLAGS. This is done by defining a make variable like: <source-filename>-CFLAGS := <whateverflags> And then modifying the proper Make rule in order to use these flags when compiling <source-filename>. 2. Use the mechanism above to add -Wno-error to CFLAGS for the following selftests: progs/btf_dump_test_case_bitfields.c progs/btf_dump_test_case_namespacing.c progs/btf_dump_test_case_packing.c progs/btf_dump_test_case_padding.c progs/btf_dump_test_case_syntax.c Note the corresponding -CFLAGS variables for these files are defined only if the selftests are being built with GCC. Note that, while compiler pragmas can generally be used to disable particular warnings per file, this 1) is only possible for warning that actually can be disabled in the command line, i.e. that have -Wno-FOO options, and 2) doesn't apply to -Wno-error. Tested in bpf-next master branch. No regressions. Signed-off-by: Jose E. Marchesi <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]