- 01 Feb, 2024 9 commits
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Andrii Nakryiko authored
Some versions of Android do not implement memfd_create() wrapper in their libc implementation, leading to build failures ([0]). On the other hand, memfd_create() is available as a syscall on quite old kernels (3.17+, while bpf() syscall itself is available since 3.18+), so it is ok to assume that syscall availability and call into it with syscall() helper to avoid Android-specific workarounds. Validated in libbpf-bootstrap's CI ([1]). [0] https://github.com/libbpf/libbpf-bootstrap/actions/runs/7701003207/job/20986080319#step:5:83 [1] https://github.com/libbpf/libbpf-bootstrap/actions/runs/7715988887/job/21031767212?pr=253Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20240201172027.604869-2-andrii@kernel.org
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Matt Bobrowski authored
There's already one main CONFIG_SECURITY_NETWORK ifdef block within the sleepable_lsm_hooks BTF set. Consolidate this duplicated ifdef block as there's no need for it and all things guarded by it should remain in one place in this specific context. Signed-off-by: Matt Bobrowski <mattbobrowski@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/Zbt1smz43GDMbVU3@google.com
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Pu Lehui authored
Enable inline bpf_kptr_xchg() test for RV64, and the test have passed as show below: Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/bpf/20240130124659.670321-3-pulehui@huaweicloud.com
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Pu Lehui authored
RV64 JIT supports 64-bit BPF_XCHG atomic instructions. At the same time, the underlying implementation of xchg() and atomic64_xchg() in RV64 both are raw_xchg() that supported 64-bit. Therefore inline bpf_kptr_xchg() will have equivalent semantics. Let's inline it for better performance. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/bpf/20240130124659.670321-2-pulehui@huaweicloud.com
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Dave Thaler authored
As discussed on the BPF IETF mailing list (see link), this patch updates the "Legacy BPF Packet access instructions" section to clarify which instructions are deprecated (vs which were never defined and so are not deprecated). Signed-off-by: Dave Thaler <dthaler1968@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yonghong.song@linux.dev> Acked-by: David Vernet <void@manifault.com> Link: https://mailarchive.ietf.org/arch/msg/bpf/5LnnKm093cGpOmDI9TnLQLBXyys Link: https://lore.kernel.org/bpf/20240131033759.3634-1-dthaler1968@gmail.com
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Eduard Zingerman authored
After recent changes, Coverity complained about inconsistent null checks in kernel_supports() function: kernel_supports(const struct bpf_object *obj, ...) [...] // var_compare_op: Comparing obj to null implies that obj might be null if (obj && obj->gen_loader) return true; // var_deref_op: Dereferencing null pointer obj if (obj->token_fd) return feat_supported(obj->feat_cache, feat_id); [...] - The original null check was introduced by commit [0], which introduced a call `kernel_supports(NULL, ...)` in function bump_rlimit_memlock(); - This call was refactored to use `feat_supported(NULL, ...)` in commit [1]. Looking at all places where kernel_supports() is called: - There is either `obj->...` access before the call; - Or `obj` comes from `prog->obj` expression, where `prog` comes from enumeration of programs in `obj`; - Or `obj` comes from `prog->obj`, where `prog` is a parameter to one of the API functions: - bpf_program__attach_kprobe_opts; - bpf_program__attach_kprobe; - bpf_program__attach_ksyscall. Assuming correct API usage, it appears that `obj` can never be null when passed to kernel_supports(). Silence the Coverity warning by removing redundant null check. [0] e542f2c4 ("libbpf: Auto-bump RLIMIT_MEMLOCK if kernel needs it for BPF") [1] d6dd1d49 ("libbpf: Further decouple feature checking logic from bpf_object") Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20240131212615.20112-1-eddyz87@gmail.com
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Alexei Starovoitov authored
Daniel Xu says: ==================== Annotate kfuncs in .BTF_ids section === Description === This is a bpf-treewide change that annotates all kfuncs as such inside .BTF_ids. This annotation eventually allows us to automatically generate kfunc prototypes from bpftool. We store this metadata inside a yet-unused flags field inside struct btf_id_set8 (thanks Kumar!). pahole will be taught where to look. More details about the full chain of events are available in commit 3's description. The accompanying pahole and bpftool changes can be viewed here on these "frozen" branches [0][1]. [0]: https://github.com/danobi/pahole/tree/kfunc_btf-v3-mailed [1]: https://github.com/danobi/linux/tree/kfunc_bpftool-mailed === Changelog === Changes from v3: * Rebase to bpf-next and add missing annotation on new kfunc Changes from v2: * Only WARN() for vmlinux kfuncs Changes from v1: * Move WARN_ON() up a call level * Also return error when kfunc set is not properly tagged * Use BTF_KFUNCS_START/END instead of flags * Rename BTF_SET8_KFUNC to BTF_SET8_KFUNCS ==================== Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/cover.1706491398.git.dxu@dxuuu.xyzSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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Daniel Xu authored
This commit marks kfuncs as such inside the .BTF_ids section. The upshot of these annotations is that we'll be able to automatically generate kfunc prototypes for downstream users. The process is as follows: 1. In source, use BTF_KFUNCS_START/END macro pair to mark kfuncs 2. During build, pahole injects into BTF a "bpf_kfunc" BTF_DECL_TAG for each function inside BTF_KFUNCS sets 3. At runtime, vmlinux or module BTF is made available in sysfs 4. At runtime, bpftool (or similar) can look at provided BTF and generate appropriate prototypes for functions with "bpf_kfunc" tag To ensure future kfunc are similarly tagged, we now also return error inside kfunc registration for untagged kfuncs. For vmlinux kfuncs, we also WARN(), as initcall machinery does not handle errors. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Acked-by: Benjamin Tissoires <bentiss@kernel.org> Link: https://lore.kernel.org/r/e55150ceecbf0a5d961e608941165c0bee7bc943.1706491398.git.dxu@dxuuu.xyzSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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Daniel Xu authored
This macro pair is functionally equivalent to BTF_SET8_START/END, except with BTF_SET8_KFUNCS flag set in the btf_id_set8 flags field. The next commit will codemod all kfunc set8s to this new variant such that all kfuncs are tagged as such in .BTF_ids section. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Link: https://lore.kernel.org/r/d536c57c7c2af428686853cc7396b7a44faa53b7.1706491398.git.dxu@dxuuu.xyzSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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- 31 Jan, 2024 2 commits
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Daniel Xu authored
This commit adds support for flags on BTF_SET8s. struct btf_id_set8 already supported 32 bits worth of flags, but was only used for alignment purposes before. We now use these bits to encode flags. The first use case is tagging kfunc sets with a flag so that pahole can recognize which BTF_ID_FLAGS(func, ..) are actual kfuncs. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Link: https://lore.kernel.org/r/7bb152ec76d6c2c930daec88e995bf18484a5ebb.1706491398.git.dxu@dxuuu.xyzSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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Manu Bretelle authored
After a recent change in the vmtest runner, this test started failing sporadically. Investigation showed that this test was subject to race condition which got exacerbated after the vm runner change. The symptoms being that the logic that waited for an ICMPv4 packet is naive and will break if 5 or more non-ICMPv4 packets make it to tap0. When ICMPv6 is enabled, the kernel will generate traffic such as ICMPv6 router solicitation... On a system with good performance, the expected ICMPv4 packet would very likely make it to the network interface promptly, but on a system with poor performance, those "guarantees" do not hold true anymore. Given that the test is IPv4 only, this change disable IPv6 in the test netns by setting `net.ipv6.conf.all.disable_ipv6` to 1. This essentially leaves "ping" as the sole generator of traffic in the network namespace. If this test was to be made IPv6 compatible, the logic in `wait_for_packet` would need to be modified. In more details... At a high level, the test does: - create a new namespace - in `setup_redirect_target` set up lo, tap0, and link_err interfaces as well as add 2 routes that attaches ingress/egress sections of `test_lwt_redirect.bpf.o` to the xmit path. - in `send_and_capture_test_packets` send an ICMP packet and read off the tap interface (using `wait_for_packet`) to check that a ICMP packet with the right size is read. `wait_for_packet` will try to read `max_retry` (5) times from the tap0 fd looking for an ICMPv4 packet matching some criteria. The problem is that when we set up the `tap0` interface, because IPv6 is enabled by default, traffic such as Router solicitation is sent through tap0, as in: # tcpdump -r /tmp/lwt_redirect.pc reading from file /tmp/lwt_redirect.pcap, link-type EN10MB (Ethernet) 04:46:23.578352 IP6 :: > ff02::1:ffc0:4427: ICMP6, neighbor solicitation, who has fe80::fcba:dff:fec0:4427, length 32 04:46:23.659522 IP6 :: > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28 04:46:24.389169 IP 10.0.0.1 > 20.0.0.9: ICMP echo request, id 122, seq 1, length 108 04:46:24.618599 IP6 fe80::fcba:dff:fec0:4427 > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28 04:46:24.619985 IP6 fe80::fcba:dff:fec0:4427 > ff02::2: ICMP6, router solicitation, length 16 04:46:24.767326 IP6 fe80::fcba:dff:fec0:4427 > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28 04:46:28.936402 IP6 fe80::fcba:dff:fec0:4427 > ff02::2: ICMP6, router solicitation, length 16 If `wait_for_packet` sees 5 non-ICMPv4 packets, it will return 0, which is what we see in: 2024-01-31T03:51:25.0336992Z test_lwt_redirect_run:PASS:netns_create 0 nsec 2024-01-31T03:51:25.0341309Z open_netns:PASS:malloc token 0 nsec 2024-01-31T03:51:25.03448444Z open_netns:PASS:open /proc/self/ns/net 0 nsec 2024-01-31T03:51:25.0350071Z open_netns:PASS:open netns fd 0 nsec 2024-01-31T03:51:25.0353516Z open_netns:PASS:setns 0 nsec 2024-01-31T03:51:25.0356560Z test_lwt_redirect_run:PASS:setns 0 nsec 2024-01-31T03:51:25.0360140Z open_tuntap:PASS:open(/dev/net/tun) 0 nsec 2024-01-31T03:51:25.0363822Z open_tuntap:PASS:ioctl(TUNSETIFF) 0 nsec 2024-01-31T03:51:25.0367402Z open_tuntap:PASS:fcntl(O_NONBLOCK) 0 nsec 2024-01-31T03:51:25.0371167Z setup_redirect_target:PASS:open_tuntap 0 nsec 2024-01-31T03:51:25.0375180Z setup_redirect_target:PASS:if_nametoindex 0 nsec 2024-01-31T03:51:25.0379929Z setup_redirect_target:PASS:ip link add link_err type dummy 0 nsec 2024-01-31T03:51:25.0384874Z setup_redirect_target:PASS:ip link set lo up 0 nsec 2024-01-31T03:51:25.0389678Z setup_redirect_target:PASS:ip addr add dev lo 10.0.0.1/32 0 nsec 2024-01-31T03:51:25.0394814Z setup_redirect_target:PASS:ip link set link_err up 0 nsec 2024-01-31T03:51:25.0399874Z setup_redirect_target:PASS:ip link set tap0 up 0 nsec 2024-01-31T03:51:25.0407731Z setup_redirect_target:PASS:ip route add 10.0.0.0/24 dev link_err encap bpf xmit obj test_lwt_redirect.bpf.o sec redir_ingress 0 nsec 2024-01-31T03:51:25.0419105Z setup_redirect_target:PASS:ip route add 20.0.0.0/24 dev link_err encap bpf xmit obj test_lwt_redirect.bpf.o sec redir_egress 0 nsec 2024-01-31T03:51:25.0427209Z test_lwt_redirect_normal:PASS:setup_redirect_target 0 nsec 2024-01-31T03:51:25.0431424Z ping_dev:PASS:if_nametoindex 0 nsec 2024-01-31T03:51:25.0437222Z send_and_capture_test_packets:FAIL:wait_for_epacket unexpected wait_for_epacket: actual 0 != expected 1 2024-01-31T03:51:25.0448298Z (/tmp/work/bpf/bpf/tools/testing/selftests/bpf/prog_tests/lwt_redirect.c:175: errno: Success) test_lwt_redirect_normal egress test fails 2024-01-31T03:51:25.0457124Z close_netns:PASS:setns 0 nsec When running in a VM which potential resource contrains, the odds that calling `ping` is not scheduled very soon after bringing `tap0` up increases, and with this the chances to get our ICMP packet pushed to position 6+ in the network trace. To confirm this indeed solves the issue, I ran the test 100 times in a row with: errors=0 successes=0 for i in `seq 1 100` do ./test_progs -t lwt_redirect/lwt_redirect_normal if [ $? -eq 0 ]; then successes=$((successes+1)) else errors=$((errors+1)) fi done echo "successes: $successes/errors: $errors" While this test would at least fail a couple of time every 10 runs, here it ran 100 times with no error. Fixes: 43a7c3ef ("selftests/bpf: Add lwt_xmit tests for BPF_REDIRECT") Signed-off-by: Manu Bretelle <chantr4@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240131053212.2247527-1-chantr4@gmail.com
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- 30 Jan, 2024 13 commits
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Martin KaFai Lau authored
Andrii Nakryiko says: ==================== Add bpf_core_cast(<ptr>, <type>) macro wrapper around bpf_rdonly_cast() kfunc to make it easier to use this functionality in BPF code. See patch #2 for BPF selftests conversions demonstrating improvements in code succinctness. ==================== Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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Andrii Nakryiko authored
Use more ergonomic bpf_core_cast() macro instead of bpf_rdonly_cast() in selftests code. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240130212023.183765-3-andrii@kernel.orgSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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Andrii Nakryiko authored
Add bpf_core_cast() macro that wraps bpf_rdonly_cast() kfunc. It's more ergonomic than kfunc, as it automatically extracts btf_id with bpf_core_type_id_kernel(), and works with type names. It also casts result to (T *) pointer. See the definition of the macro, it's self-explanatory. libbpf declares bpf_rdonly_cast() extern as __weak __ksym and should be safe to not conflict with other possible declarations in user code. But we do have a conflict with current BPF selftests that declare their externs with first argument as `void *obj`, while libbpf opts into more permissive `const void *obj`. This causes conflict, so we fix up BPF selftests uses in the same patch. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240130212023.183765-2-andrii@kernel.orgSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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Alexei Starovoitov authored
Andrii Nakryiko says: ==================== Trusted PTR_TO_BTF_ID arg support in global subprogs This patch set follows recent changes that added btf_decl_tag-based argument annotation support for global subprogs. This time we add ability to pass PTR_TO_BTF_ID (BTF-aware kernel pointers) arguments into global subprograms. We support explicitly trusted arguments only, for now. Patch #1 adds logic for arg:trusted tag support on the verifier side. Default semantic of such arguments is non-NULL, enforced on caller side. But patch #2 adds arg:nullable tag that can be combined with arg:trusted to make callee explicitly do the NULL check, which helps implement "optional" PTR_TO_BTF_ID arguments. Patch #3 adds libbpf-side __arg_trusted and __arg_nullable macros. Patch #4 adds a bunch of tests validating __arg_trusted in combination with __arg_nullable. v2->v3: - went back to arg:nullable and __arg_nullable naming; - rebased on latest bpf-next after prepartory patches landed; v1->v2: - added fix up to type enforcement changes, landed earlier; - dropped bpf_core_cast() changes, will post them separately, as they now are not used in added tests; - dropped arg:untrusted support (Alexei); - renamed arg:nullable to arg:maybe_null (Alexei); - and also added task_struct___local flavor tests (Alexei). ==================== Link: https://lore.kernel.org/r/20240130000648.2144827-1-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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Andrii Nakryiko authored
Add a bunch of test cases validating behavior of __arg_trusted and its combination with __arg_nullable tag. We also validate CO-RE flavor support by kernel for __arg_trusted args. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240130000648.2144827-5-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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Andrii Nakryiko authored
Add __arg_trusted to annotate global func args that accept trusted PTR_TO_BTF_ID arguments. Also add __arg_nullable to combine with __arg_trusted (and maybe other tags in the future) to force global subprog itself (i.e., callee) to do NULL checks, as opposed to default non-NULL semantics (and thus caller's responsibility to ensure non-NULL values). Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240130000648.2144827-4-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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Andrii Nakryiko authored
Add ability to mark arg:trusted arguments with optional arg:nullable tag to mark it as PTR_TO_BTF_ID_OR_NULL variant, which will allow callers to pass NULL, and subsequently will force global subprog's code to do NULL check. This allows to have "optional" PTR_TO_BTF_ID values passed into global subprogs. For now arg:nullable cannot be combined with anything else. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240130000648.2144827-3-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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Andrii Nakryiko authored
Add support for passing PTR_TO_BTF_ID registers to global subprogs. Currently only PTR_TRUSTED flavor of PTR_TO_BTF_ID is supported. Non-NULL semantics is assumed, so caller will be forced to prove PTR_TO_BTF_ID can't be NULL. Note, we disallow global subprogs to destroy passed in PTR_TO_BTF_ID arguments, even the trusted one. We achieve that by not setting ref_obj_id when validating subprog code. This basically enforces (in Rust terms) borrowing semantics vs move semantics. Borrowing semantics seems to be a better fit for isolated global subprog validation approach. Implementation-wise, we utilize existing logic for matching user-provided BTF type to kernel-side BTF type, used by BPF CO-RE logic and following same matching rules. We enforce a unique match for types. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240130000648.2144827-2-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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Jose E. Marchesi authored
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.htmlSigned-off-by: Jose E. Marchesi <jose.marchesi@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20240130113624.24940-1-jose.marchesi@oracle.com
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Jose E. Marchesi authored
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/bae1205a-b6e5-4e46-8e20-520d7c327f7a@linux.dev/T/#t Tested in bpf-next master. No regressions. Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/bae1205a-b6e5-4e46-8e20-520d7c327f7a@linux.dev Link: https://lore.kernel.org/bpf/20240130110343.11217-1-jose.marchesi@oracle.com
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Haiyue Wang authored
Replace the '(1ULL << *)' with the macro BIT_ULL(nr). Signed-off-by: Haiyue Wang <haiyue.wang@intel.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240127134901.3698613-1-haiyue.wang@intel.com
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Jose E. Marchesi authored
The generated bpf_helper_defs.h file currently contains definitions like this for the kernel helpers, which are static objects: static void *(*bpf_map_lookup_elem)(void *map, const void *key) = (void *) 1; These work well in both clang and GCC because both compilers do constant propagation with -O1 and higher optimization, resulting in `call 1' BPF instructions being generated, which are calls to kernel helpers. However, there is a discrepancy on how the -Wunused-variable warning (activated by -Wall) is handled in these compilers: - clang will not emit -Wunused-variable warnings for static variables defined in C header files, be them constant or not constant. - GCC will not emit -Wunused-variable warnings for _constant_ static variables defined in header files, but it will emit warnings for non-constant static variables defined in header files. There is no reason for these bpf_helpers_def.h pointers to not be declared constant, and it is actually desirable to do so, since their values are not to be changed. So this patch modifies bpf_doc.py to generate prototypes like: static void *(* const bpf_map_lookup_elem)(void *map, const void *key) = (void *) 1; This allows GCC to not error while compiling BPF programs with `-Wall -Werror', while still being able to detect and error on legitimate unused variables in the program themselves. This change doesn't impact the desired constant propagation in neither Clang nor GCC with -O1 and higher. On the contrary, being declared as constant may increase the odds they get constant folded when used/referred to in certain circumstances. Tested in bpf-next master. No regressions. Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20240127185031.29854-1-jose.marchesi@oracle.com
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Ian Rogers authored
As CONFIG_DEBUG_INFO_BTF is default off the existing "failed to find valid kernel BTF" message makes diagnosing the kernel build issue somewhat cryptic. Add a little more detail with the hope of helping users. Before: ``` libbpf: failed to find valid kernel BTF libbpf: Error loading vmlinux BTF: -3 ``` After not accessible: ``` libbpf: kernel BTF is missing at '/sys/kernel/btf/vmlinux', was CONFIG_DEBUG_INFO_BTF enabled? libbpf: failed to find valid kernel BTF libbpf: Error loading vmlinux BTF: -3 ``` After not readable: ``` libbpf: failed to read kernel BTF from (/sys/kernel/btf/vmlinux): -1 ``` Closes: https://lore.kernel.org/bpf/CAP-5=fU+DN_+Y=Y4gtELUsJxKNDDCOvJzPHvjUVaUoeFAzNnig@mail.gmail.com/Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240125231840.1647951-1-irogers@google.com
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- 29 Jan, 2024 16 commits
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Florian Lehner authored
Remove the duplicate check on type and unify result. Signed-off-by: Florian Lehner <dev@der-flo.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/bpf/20240120150920.3370-1-dev@der-flo.net
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Jose E. Marchesi authored
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 <jose.marchesi@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20240127100702.21549-1-jose.marchesi@oracle.com
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Martin KaFai Lau authored
In s390, CI reported that the sock_iter_batch selftest hits this error very often: 2024-01-26T16:56:49.3091804Z Bind /proc/self/ns/net -> /run/netns/sock_iter_batch_netns failed: No such file or directory 2024-01-26T16:56:49.3149524Z Cannot remove namespace file "/run/netns/sock_iter_batch_netns": No such file or directory 2024-01-26T16:56:49.3772213Z test_sock_iter_batch:FAIL:ip netns add sock_iter_batch_netns unexpected error: 256 (errno 0) It happens very often in s390 but Manu also noticed it happens very sparsely in other arch also. It turns out the default dash shell does not recognize "&>" as a redirection operator, so the command went to the background. In the sock_iter_batch selftest, the "ip netns delete" went into background and then race with the following "ip netns add" command. This patch replaces the "&> /dev/null" usage with ">/dev/null 2>&1" and does this redirection in the SYS_NOFAIL macro instead of doing it individually by its caller. The SYS_NOFAIL callers do not care about failure, so it is no harm to do this redirection even if some of the existing callers do not redirect to /dev/null now. It touches different test files, so I skipped the Fixes tags in this patch. Some of the changed tests do not use "&>" but they use the SYS_NOFAIL, so these tests are also changed to avoid doing its own redirection because SYS_NOFAIL does it internally now. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20240127025017.950825-1-martin.lau@linux.devSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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Andrii Nakryiko authored
Now that bpf and bpf-next trees converged and we don't run the risk of merge conflicts, move btf_validate_prog_ctx_type() into its most logical place inside the main logic loop. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240125205510.3642094-4-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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Andrii Nakryiko authored
Adjust PERF_EVENT type enforcement around __arg_ctx to match exactly what kernel is doing. Fixes: 76ec90a9 ("libbpf: warn on unexpected __arg_ctx type when rewriting BTF") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240125205510.3642094-3-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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Andrii Nakryiko authored
Now that feature detection code is in bpf-next tree, integrate __arg_ctx kernel-side support into kernel_supports() framework. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240125205510.3642094-2-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>
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Yonghong Song authored
For 64-bit immediate instruction, 'BPF_IMM | BPF_DW | BPF_LD' and src_reg=[0-6], the current documentation describes the 64-bit immediate is constructed by: imm64 = (next_imm << 32) | imm But actually imm64 is only used when src_reg=0. For all other variants (src_reg != 0), 'imm' and 'next_imm' have separate special encoding requirement and imm64 cannot be easily used to describe instruction semantics. This patch clarifies that 64-bit immediate instructions use two 32-bit immediate values instead of a 64-bit immediate value, so later describing individual 64-bit immediate instructions becomes less confusing. Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Dave Thaler <dthaler1968@gmail.com> Link: https://lore.kernel.org/bpf/20240127194629.737589-1-yonghong.song@linux.dev
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Menglong Dong authored
It seems that the field "mod" in struct bpf_trampoline is not used anywhere after the commit 31bf1dbc ("bpf: Fix attaching fentry/fexit/fmod_ret/lsm to modules"). So we can just remove it now. Fixes: 31bf1dbc ("bpf: Fix attaching fentry/fexit/fmod_ret/lsm to modules") Signed-off-by: Menglong Dong <dongmenglong.8@bytedance.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20240128055443.413291-1-dongmenglong.8@bytedance.com
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Geliang Tang authored
bpf_testmod_exit() does not need to have a return value (given the void), so this patch drops this useless 'return' in it. Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/5765b287ea088f0c820f2a834faf9b20fb2f8215.1706442113.git.tanggeliang@kylinos.cn
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Pu Lehui authored
Optimize bswap instructions by rev8 Zbb instruction conbined with srli instruction. And Optimize 16-bit zero-extension with Zbb support. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Björn Töpel <bjorn@rivosinc.com> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/bpf/20240115131235.2914289-7-pulehui@huaweicloud.com
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Pu Lehui authored
Add 8-bit and 16-bit sign-extention wraper with Zbb support to optimize sign-extension mov instructions. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Björn Töpel <bjorn@rivosinc.com> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/bpf/20240115131235.2914289-6-pulehui@huaweicloud.com
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Pu Lehui authored
Add necessary Zbb instructions introduced by [0] to reduce code size and improve performance of RV64 JIT. Meanwhile, a runtime deteted helper is added to check whether the CPU supports Zbb instructions. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Björn Töpel <bjorn@rivosinc.com> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://github.com/riscv/riscv-bitmanip/releases/download/1.0.0/bitmanip-1.0.0-38-g865e7a7.pdf [0] Link: https://lore.kernel.org/bpf/20240115131235.2914289-5-pulehui@huaweicloud.com
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Pu Lehui authored
There are many extension helpers in the current branch instructions, and the implementation is a bit complicated. We simplify this logic through two simple extension helpers with alternate register. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Björn Töpel <bjorn@rivosinc.com> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/bpf/20240115131235.2914289-4-pulehui@huaweicloud.com
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Pu Lehui authored
For code unification, add emit_zextw wrapper to unify all the 32-bit zero-extension operations. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Björn Töpel <bjorn@rivosinc.com> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/bpf/20240115131235.2914289-3-pulehui@huaweicloud.com
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Pu Lehui authored
For code unification, add emit_sextw wrapper to unify all the 32-bit sign-extension operations. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Björn Töpel <bjorn@rivosinc.com> Acked-by: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/bpf/20240115131235.2914289-2-pulehui@huaweicloud.com
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Andrii Nakryiko authored
Android implementation of libc errors out with -EINVAL in faccessat() if passed AT_EACCESS ([0]), this leads to ridiculous issue with libbpf refusing to load /sys/kernel/btf/vmlinux on Androids ([1]). Fix by detecting Android and redefining AT_EACCESS to 0, it's equivalent on Android. [0] https://android.googlesource.com/platform/bionic/+/refs/heads/android13-release/libc/bionic/faccessat.cpp#50 [1] https://github.com/libbpf/libbpf-bootstrap/issues/250#issuecomment-1911324250 Fixes: 6a4ab886 ("libbpf: Fix the case of running as non-root with capabilities") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20240126220944.2497665-1-andrii@kernel.org
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