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2022-02-03selftests/bpf: Migrate from bpf_prog_test_runDelyan Kratunov38-523/+649
bpf_prog_test_run is being deprecated in favor of the OPTS-based bpf_prog_test_run_opts. We end up unable to use CHECK in most cases, so replace usages with ASSERT_* calls. Signed-off-by: Delyan Kratunov <delyank@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220202235423.1097270-2-delyank@fb.com
2022-02-02Merge branch 'bpf-btf-dwarf5'Daniel Borkmann0-0/+0
Nathan Chancellor says: ==================== This series allows CONFIG_DEBUG_INFO_DWARF5 to be selected with CONFIG_DEBUG_INFO_BTF=y by checking the pahole version. The first four patches add CONFIG_PAHOLE_VERSION and scripts/pahole-version.sh to clean up all the places that pahole's version is transformed into a 3-digit form. The fourth patch adds a PAHOLE_VERSION dependency to DEBUG_INFO_DWARF5 so that there are no build errors when it is selected with DEBUG_INFO_BTF. I build tested Fedora's aarch64 and x86_64 config with ToT clang 14.0.0 and GCC 11 with CONFIG_DEBUG_INFO_DWARF5 enabled with both pahole 1.21 and 1.23. ==================== Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2022-02-02lib/Kconfig.debug: Allow BTF + DWARF5 with pahole 1.21+Nathan Chancellor1-1/+1
Commit 98cd6f521f10 ("Kconfig: allow explicit opt in to DWARF v5") prevented CONFIG_DEBUG_INFO_DWARF5 from being selected when CONFIG_DEBUG_INFO_BTF is enabled because pahole had issues with clang's DWARF5 info. This was resolved by [1], which is in pahole v1.21. Allow DEBUG_INFO_DWARF5 to be selected with DEBUG_INFO_BTF when using pahole v1.21 or newer. [1]: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=7d8e829f636f47aba2e1b6eda57e74d8e31f733c Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220201205624.652313-6-nathan@kernel.org
2022-02-02lib/Kconfig.debug: Use CONFIG_PAHOLE_VERSIONNathan Chancellor1-2/+2
Now that CONFIG_PAHOLE_VERSION exists, use it in the definition of CONFIG_PAHOLE_HAS_SPLIT_BTF and CONFIG_PAHOLE_HAS_BTF_TAG to reduce the amount of duplication across the tree. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220201205624.652313-5-nathan@kernel.org
2022-02-02scripts/pahole-flags.sh: Use pahole-version.shNathan Chancellor1-1/+1
Use pahole-version.sh to get pahole's version code to reduce the amount of duplication across the tree. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220201205624.652313-4-nathan@kernel.org
2022-02-02kbuild: Add CONFIG_PAHOLE_VERSIONNathan Chancellor3-0/+18
There are a few different places where pahole's version is turned into a three digit form with the exact same command. Move this command into scripts/pahole-version.sh to reduce the amount of duplication across the tree. Create CONFIG_PAHOLE_VERSION so the version code can be used in Kconfig to enable and disable configuration options based on the pahole version, which is already done in a couple of places. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220201205624.652313-3-nathan@kernel.org
2022-02-02MAINTAINERS: Add scripts/pahole-flags.sh to BPF sectionNathan Chancellor1-0/+1
Currently, scripts/pahole-flags.sh has no formal maintainer. Add it to the BPF section so that patches to it can be properly reviewed and picked up. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220201205624.652313-2-nathan@kernel.org
2022-02-02Merge branch 'bpf-drop-libbpf-from-preload'Daniel Borkmann7-452/+527
Alexei Starovoitov says: ==================== CO-RE in the kernel support allows bpf preload to switch to light skeleton and remove libbpf dependency. This reduces the size of bpf_preload_umd from 300kbyte to 19kbyte and eventually will make "kernel skeleton" possible. ==================== Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2022-02-02bpf: Drop libbpf, libelf, libz dependency from bpf preload.Alexei Starovoitov1-26/+2
Drop libbpf, libelf, libz dependency from bpf preload. This reduces bpf_preload_umd binary size from 1.7M to 30k unstripped with debug info and from 300k to 19k stripped. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-8-alexei.starovoitov@gmail.com
2022-02-02bpf: Open code obj_get_info_by_fd in bpf preload.Alexei Starovoitov1-1/+17
Open code obj_get_info_by_fd in bpf preload. It's the last part of libbpf that preload/iterators were using. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-7-alexei.starovoitov@gmail.com
2022-02-02bpf: Convert bpf preload to light skeleton.Alexei Starovoitov4-420/+436
Convert bpffs preload iterators to light skeleton. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-6-alexei.starovoitov@gmail.com
2022-02-02bpf: Remove unnecessary setrlimit from bpf preload.Alexei Starovoitov1-2/+0
BPF programs and maps are memcg accounted. setrlimit is obsolete. Remove its use from bpf preload. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-5-alexei.starovoitov@gmail.com
2022-02-02libbpf: Open code raw_tp_open and link_create commands.Alexei Starovoitov2-3/+29
Open code raw_tracepoint_open and link_create used by light skeleton to be able to avoid full libbpf eventually. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-4-alexei.starovoitov@gmail.com
2022-02-02libbpf: Open code low level bpf commands.Alexei Starovoitov1-2/+42
Open code low level bpf commands used by light skeleton to be able to avoid full libbpf eventually. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-3-alexei.starovoitov@gmail.com
2022-02-02libbpf: Add support for bpf iter in light skeleton.Alexei Starovoitov1-1/+4
bpf iterator programs should use bpf_link_create to attach instead of bpf_raw_tracepoint_open like other tracing programs. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20220131220528.98088-2-alexei.starovoitov@gmail.com
2022-02-01Merge branch 'libbpf: deprecate xdp_cpumap, xdp_devmap and classifier sec ↵Andrii Nakryiko9-14/+22
definitions' Lorenzo Bianconi says: ==================== Deprecate xdp_cpumap, xdp_devmap and classifier sec definitions. Update cpumap/devmap samples and kselftests. Changes since v2: - update warning log - split libbpf and samples/kselftests changes - deprecate classifier sec definition Changes since v1: - refer to Libbpf-1.0-migration-guide in the warning rised by libbpf ==================== Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2022-02-01samples/bpf: Update cpumap/devmap sec_nameLorenzo Bianconi3-6/+6
Substitute deprecated xdp_cpumap and xdp_devmap sec_name with xdp/cpumap and xdp/devmap respectively. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/509201497c6c4926bc941f1cba24173cf500e760.1643727185.git.lorenzo@kernel.org
2022-02-01selftests/bpf: Update cpumap/devmap sec_nameLorenzo Bianconi5-5/+5
Substitute deprecated xdp_cpumap and xdp_devmap sec_name with xdp/cpumap and xdp/devmap respectively in bpf kselftests. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/9a4286cd36781e2c31ba3773bfdcf45cf1bbaa9e.1643727185.git.lorenzo@kernel.org
2022-02-01libbpf: Deprecate xdp_cpumap, xdp_devmap and classifier sec definitionsLorenzo Bianconi1-3/+11
Deprecate xdp_cpumap, xdp_devmap and classifier sec definitions. Introduce xdp/devmap and xdp/cpumap definitions according to the standard for SEC("") in libbpf: - prog_type.prog_flags/attach_place Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/5c7bd9426b3ce6a31d9a4b1f97eb299e1467fc52.1643727185.git.lorenzo@kernel.org
2022-02-01libbpf: Deprecate btf_ext rec_size APIsDave Marchevsky1-2/+4
btf_ext__{func,line}_info_rec_size functions are used in conjunction with already-deprecated btf_ext__reloc_{func,line}_info functions. Since struct btf_ext is opaque to the user it was necessary to expose rec_size getters in the past. btf_ext__reloc_{func,line}_info were deprecated in commit 8505e8709b5ee ("libbpf: Implement generalized .BTF.ext func/line info adjustment") as they're not compatible with support for multiple programs per section. It was decided[0] that users of these APIs should implement their own .btf.ext parsing to access this data, in which case the rec_size getters are unnecessary. So deprecate them from libbpf 0.7.0 onwards. [0] Closes: https://github.com/libbpf/libbpf/issues/277 Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220201014610.3522985-1-davemarchevsky@fb.com
2022-01-31bpf: make bpf_copy_from_user_task() gpl onlyKenta Tada1-1/+1
access_process_vm() is exported by EXPORT_SYMBOL_GPL(). Signed-off-by: Kenta Tada <Kenta.Tada@sony.com> Link: https://lore.kernel.org/r/20220128170906.21154-1-Kenta.Tada@sony.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-31Merge branch 'Split bpf_sock dst_port field'Alexei Starovoitov6-23/+173
Jakub Sitnicki says: ==================== This is a follow-up to discussion around the idea of making dst_port in struct bpf_sock a 16-bit field that happened in [1]. v2: - use an anonymous field for zero padding (Alexei) v1: - keep dst_field offset unchanged to prevent existing BPF program breakage (Martin) - allow 8-bit loads from dst_port[0] and [1] - add test coverage for the verifier and the context access converter [1] https://lore.kernel.org/bpf/87sftbobys.fsf@cloudflare.com/ ==================== Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-31selftests/bpf: Extend verifier and bpf_sock tests for dst_port loadsJakub Sitnicki4-21/+162
Add coverage to the verifier tests and tests for reading bpf_sock fields to ensure that 32-bit, 16-bit, and 8-bit loads from dst_port field are allowed only at intended offsets and produce expected values. While 16-bit and 8-bit access to dst_port field is straight-forward, 32-bit wide loads need be allowed and produce a zero-padded 16-bit value for backward compatibility. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/r/20220130115518.213259-3-jakub@cloudflare.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-31bpf: Make dst_port field in struct bpf_sock 16-bit wideJakub Sitnicki2-2/+11
Menglong Dong reports that the documentation for the dst_port field in struct bpf_sock is inaccurate and confusing. From the BPF program PoV, the field is a zero-padded 16-bit integer in network byte order. The value appears to the BPF user as if laid out in memory as so: offsetof(struct bpf_sock, dst_port) + 0 <port MSB> + 8 <port LSB> +16 0x00 +24 0x00 32-, 16-, and 8-bit wide loads from the field are all allowed, but only if the offset into the field is 0. 32-bit wide loads from dst_port are especially confusing. The loaded value, after converting to host byte order with bpf_ntohl(dst_port), contains the port number in the upper 16-bits. Remove the confusion by splitting the field into two 16-bit fields. For backward compatibility, allow 32-bit wide loads from offsetof(struct bpf_sock, dst_port). While at it, allow loads 8-bit loads at offset [0] and [1] from dst_port. Reported-by: Menglong Dong <imagedong@tencent.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/r/20220130115518.213259-2-jakub@cloudflare.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-28Merge branch 'selftests/bpf: use temp netns for testing'Alexei Starovoitov7-195/+213
Hangbin Liu says: ==================== There are some bpf tests using hard code netns name like ns0, ns1, etc. This kind of ns name is easily used by other tests or system. If there is already a such netns, all the related tests will failed. So let's use temp netns name for testing. The first patch not only change to temp netns. But also fixed an interface index issue. So I add fixes tag. For the later patches, I think that should be an update instead of fixes, so the fixes tag is not added. ==================== Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-28selftests/bpf/test_xdp_redirect: use temp netns for testingHangbin Liu1-14/+16
Use temp netns instead of hard code name for testing in case the netns already exists. Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Acked-by: William Tu <u9012063@gmail.com> Link: https://lore.kernel.org/r/20220125081717.1260849-8-liuhangbin@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-28selftests/bpf/test_xdp_meta: use temp netns for testingHangbin Liu1-18/+20
Use temp netns instead of hard code name for testing in case the netns already exists. Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Link: https://lore.kernel.org/r/20220125081717.1260849-7-liuhangbin@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-28selftests/bpf/test_tcp_check_syncookie: use temp netns for testingHangbin Liu1-2/+3
Use temp netns instead of hard code name for testing in case the netns already exists. Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Acked-by: Lorenz Bauer <lmb@cloudflare.com> Link: https://lore.kernel.org/r/20220125081717.1260849-6-liuhangbin@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-28selftests/bpf/test_lwt_seg6local: use temp netns for testingHangbin Liu1-82/+88
Use temp netns instead of hard code name for testing in case the netns already exists. Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Link: https://lore.kernel.org/r/20220125081717.1260849-5-liuhangbin@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-28selftests/bpf/test_xdp_vlan: use temp netns for testingHangbin Liu1-32/+34
Use temp netns instead of hard code name for testing in case the netns already exists. Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Link: https://lore.kernel.org/r/20220125081717.1260849-4-liuhangbin@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-28selftests/bpf/test_xdp_veth: use temp netns for testingHangbin Liu1-18/+21
Use temp netns instead of hard code name for testing in case the netns already exists. Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Link: https://lore.kernel.org/r/20220125081717.1260849-3-liuhangbin@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-28selftests/bpf/test_xdp_redirect_multi: use temp netns for testingHangbin Liu1-29/+31
Use temp netns instead of hard code name for testing in case the netns already exists. Remove the hard code interface index when creating the veth interfaces. Because when the system loads some virtual interface modules, e.g. tunnels. the ifindex of 2 will be used and the cmd will fail. As the netns has not created if checking environment failed. Trap the clean up function after checking env. Fixes: 8955c1a32987 ("selftests/bpf/xdp_redirect_multi: Limit the tests in netns") Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Acked-by: William Tu <u9012063@gmail.com> Link: https://lore.kernel.org/r/20220125081717.1260849-2-liuhangbin@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-28bpf, x86: Remove unnecessary handling of BPF_SUB atomic opHou Tao1-1/+0
According to the LLVM commit (https://reviews.llvm.org/D72184), sync_fetch_and_sub() is implemented as a negation followed by sync_fetch_and_add(), so there will be no BPF_SUB op, thus just remove it. BPF_SUB is also rejected by the verifier anyway. Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Brendan Jackman <jackmanb@google.com> Link: https://lore.kernel.org/bpf/20220127083240.1425481-1-houtao1@huawei.com
2022-01-27Merge branch 'bpf: add __user tagging support in vmlinux BTF'Alexei Starovoitov14-28/+252
Yonghong Song says: ==================== The __user attribute is currently mainly used by sparse for type checking. The attribute indicates whether a memory access is in user memory address space or not. Such information is important during tracing kernel internal functions or data structures as accessing user memory often has different mechanisms compared to accessing kernel memory. For example, the perf-probe needs explicit command line specification to indicate a particular argument or string in user-space memory ([1], [2], [3]). Currently, vmlinux BTF is available in kernel with many distributions. If __user attribute information is available in vmlinux BTF, the explicit user memory access information from users will not be necessary as the kernel can figure it out by itself with vmlinux BTF. Besides the above possible use for perf/probe, another use case is for bpf verifier. Currently, for bpf BPF_PROG_TYPE_TRACING type of bpf programs, users can write direct code like p->m1->m2 and "p" could be a function parameter. Without __user information in BTF, the verifier will assume p->m1 accessing kernel memory and will generate normal loads. Let us say "p" actually tagged with __user in the source code. In such cases, p->m1 is actually accessing user memory and direct load is not right and may produce incorrect result. For such cases, bpf_probe_read_user() will be the correct way to read p->m1. To support encoding __user information in BTF, a new attribute __attribute__((btf_type_tag("<arbitrary_string>"))) is implemented in clang ([4]). For example, if we have #define __user __attribute__((btf_type_tag("user"))) during kernel compilation, the attribute "user" information will be preserved in dwarf. After pahole converting dwarf to BTF, __user information will be available in vmlinux BTF and such information can be used by bpf verifier, perf/probe or other use cases. Currently btf_type_tag is only supported in clang (>= clang14) and pahole (>= 1.23). gcc support is also proposed and under development ([5]). In the rest of patch set, Patch 1 added support of __user btf_type_tag during compilation. Patch 2 added bpf verifier support to utilize __user tag information to reject bpf programs not using proper helper to access user memories. Patches 3-5 are for bpf selftests which demonstrate verifier can reject direct user memory accesses. [1] http://lkml.kernel.org/r/155789874562.26965.10836126971405890891.stgit@devnote2 [2] http://lkml.kernel.org/r/155789872187.26965.4468456816590888687.stgit@devnote2 [3] http://lkml.kernel.org/r/155789871009.26965.14167558859557329331.stgit@devnote2 [4] https://reviews.llvm.org/D111199 [5] https://lore.kernel.org/bpf/0cbeb2fb-1a18-f690-e360-24b1c90c2a91@fb.com/ Changelog: v2 -> v3: - remove FLAG_DONTCARE enumerator and just use 0 as dontcare flag. - explain how btf type_tag is encoded in btf type chain. v1 -> v2: - use MEM_USER flag for PTR_TO_BTF_ID reg type instead of a separate field to encode __user tag. - add a test with kernel function __sys_getsockname which has __user tagged argument. ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-27docs/bpf: clarify how btf_type_tag gets encoded in the type chainYonghong Song1-0/+13
Clarify where the BTF_KIND_TYPE_TAG gets encoded in the type chain, so applications and kernel can properly parse them. Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220127154627.665163-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-27selftests/bpf: specify pahole version requirement for btf_tag testYonghong Song1-0/+2
Specify pahole version requirement (1.23) for btf_tag subtests btf_type_tag_user_{mod1, mod2, vmlinux}. Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220127154622.663337-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-27selftests/bpf: add a selftest with __user tagYonghong Song3-0/+151
Added a selftest with three__user usages: a __user pointer-type argument in bpf_testmod, a __user pointer-type struct member in bpf_testmod, and a __user pointer-type struct member in vmlinux. In all cases, directly accessing the user memory will result verification failure. $ ./test_progs -v -n 22/3 ... libbpf: prog 'test_user1': BPF program load failed: Permission denied libbpf: prog 'test_user1': -- BEGIN PROG LOAD LOG -- R1 type=ctx expected=fp 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 ; int BPF_PROG(test_user1, struct bpf_testmod_btf_type_tag_1 *arg) 0: (79) r1 = *(u64 *)(r1 +0) func 'bpf_testmod_test_btf_type_tag_user_1' arg0 has btf_id 136561 type STRUCT 'bpf_testmod_btf_type_tag_1' 1: R1_w=user_ptr_bpf_testmod_btf_type_tag_1(id=0,off=0,imm=0) ; g = arg->a; 1: (61) r1 = *(u32 *)(r1 +0) R1 invalid mem access 'user_ptr_' ... #22/3 btf_tag/btf_type_tag_user_mod1:OK $ ./test_progs -v -n 22/4 ... libbpf: prog 'test_user2': BPF program load failed: Permission denied libbpf: prog 'test_user2': -- BEGIN PROG LOAD LOG -- R1 type=ctx expected=fp 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 ; int BPF_PROG(test_user2, struct bpf_testmod_btf_type_tag_2 *arg) 0: (79) r1 = *(u64 *)(r1 +0) func 'bpf_testmod_test_btf_type_tag_user_2' arg0 has btf_id 136563 type STRUCT 'bpf_testmod_btf_type_tag_2' 1: R1_w=ptr_bpf_testmod_btf_type_tag_2(id=0,off=0,imm=0) ; g = arg->p->a; 1: (79) r1 = *(u64 *)(r1 +0) ; R1_w=user_ptr_bpf_testmod_btf_type_tag_1(id=0,off=0,imm=0) ; g = arg->p->a; 2: (61) r1 = *(u32 *)(r1 +0) R1 invalid mem access 'user_ptr_' ... #22/4 btf_tag/btf_type_tag_user_mod2:OK $ ./test_progs -v -n 22/5 ... libbpf: prog 'test_sys_getsockname': BPF program load failed: Permission denied libbpf: prog 'test_sys_getsockname': -- BEGIN PROG LOAD LOG -- R1 type=ctx expected=fp 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 ; int BPF_PROG(test_sys_getsockname, int fd, struct sockaddr *usockaddr, 0: (79) r1 = *(u64 *)(r1 +8) func '__sys_getsockname' arg1 has btf_id 2319 type STRUCT 'sockaddr' 1: R1_w=user_ptr_sockaddr(id=0,off=0,imm=0) ; g = usockaddr->sa_family; 1: (69) r1 = *(u16 *)(r1 +0) R1 invalid mem access 'user_ptr_' ... #22/5 btf_tag/btf_type_tag_user_vmlinux:OK Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220127154616.659314-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-27selftests/bpf: rename btf_decl_tag.c to test_btf_decl_tag.cYonghong Song2-4/+4
The uapi btf.h contains the following declaration: struct btf_decl_tag { __s32 component_idx; }; The skeleton will also generate a struct with name "btf_decl_tag" for bpf program btf_decl_tag.c. Rename btf_decl_tag.c to test_btf_decl_tag.c so the corresponding skeleton struct name becomes "test_btf_decl_tag". This way, we could include uapi btf.h in prog_tests/btf_tag.c. There is no functionality change for this patch. Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220127154611.656699-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-27bpf: reject program if a __user tagged memory accessed in kernel wayYonghong Song6-24/+71
BPF verifier supports direct memory access for BPF_PROG_TYPE_TRACING type of bpf programs, e.g., a->b. If "a" is a pointer pointing to kernel memory, bpf verifier will allow user to write code in C like a->b and the verifier will translate it to a kernel load properly. If "a" is a pointer to user memory, it is expected that bpf developer should be bpf_probe_read_user() helper to get the value a->b. Without utilizing BTF __user tagging information, current verifier will assume that a->b is a kernel memory access and this may generate incorrect result. Now BTF contains __user information, it can check whether the pointer points to a user memory or not. If it is, the verifier can reject the program and force users to use bpf_probe_read_user() helper explicitly. In the future, we can easily extend btf_add_space for other address space tagging, for example, rcu/percpu etc. Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220127154606.654961-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-27compiler_types: define __user as __attribute__((btf_type_tag("user")))Yonghong Song2-0/+11
The __user attribute is currently mainly used by sparse for type checking. The attribute indicates whether a memory access is in user memory address space or not. Such information is important during tracing kernel internal functions or data structures as accessing user memory often has different mechanisms compared to accessing kernel memory. For example, the perf-probe needs explicit command line specification to indicate a particular argument or string in user-space memory ([1], [2], [3]). Currently, vmlinux BTF is available in kernel with many distributions. If __user attribute information is available in vmlinux BTF, the explicit user memory access information from users will not be necessary as the kernel can figure it out by itself with vmlinux BTF. Besides the above possible use for perf/probe, another use case is for bpf verifier. Currently, for bpf BPF_PROG_TYPE_TRACING type of bpf programs, users can write direct code like p->m1->m2 and "p" could be a function parameter. Without __user information in BTF, the verifier will assume p->m1 accessing kernel memory and will generate normal loads. Let us say "p" actually tagged with __user in the source code. In such cases, p->m1 is actually accessing user memory and direct load is not right and may produce incorrect result. For such cases, bpf_probe_read_user() will be the correct way to read p->m1. To support encoding __user information in BTF, a new attribute __attribute__((btf_type_tag("<arbitrary_string>"))) is implemented in clang ([4]). For example, if we have #define __user __attribute__((btf_type_tag("user"))) during kernel compilation, the attribute "user" information will be preserved in dwarf. After pahole converting dwarf to BTF, __user information will be available in vmlinux BTF. The following is an example with latest upstream clang (clang14) and pahole 1.23: [$ ~] cat test.c #define __user __attribute__((btf_type_tag("user"))) int foo(int __user *arg) { return *arg; } [$ ~] clang -O2 -g -c test.c [$ ~] pahole -JV test.o ... [1] INT int size=4 nr_bits=32 encoding=SIGNED [2] TYPE_TAG user type_id=1 [3] PTR (anon) type_id=2 [4] FUNC_PROTO (anon) return=1 args=(3 arg) [5] FUNC foo type_id=4 [$ ~] You can see for the function argument "int __user *arg", its type is described as PTR -> TYPE_TAG(user) -> INT The kernel can use this information for bpf verification or other use cases. Current btf_type_tag is only supported in clang (>= clang14) and pahole (>= 1.23). gcc support is also proposed and under development ([5]). [1] http://lkml.kernel.org/r/155789874562.26965.10836126971405890891.stgit@devnote2 [2] http://lkml.kernel.org/r/155789872187.26965.4468456816590888687.stgit@devnote2 [3] http://lkml.kernel.org/r/155789871009.26965.14167558859557329331.stgit@devnote2 [4] https://reviews.llvm.org/D111199 [5] https://lore.kernel.org/bpf/0cbeb2fb-1a18-f690-e360-24b1c90c2a91@fb.com/ Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220127154600.652613-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-27cgroup/bpf: fast path skb BPF filteringPavel Begunkov4-46/+37
Even though there is a static key protecting from overhead from cgroup-bpf skb filtering when there is nothing attached, in many cases it's not enough as registering a filter for one type will ruin the fast path for all others. It's observed in production servers I've looked at but also in laptops, where registration is done during init by systemd or something else. Add a per-socket fast path check guarding from such overhead. This affects both receive and transmit paths of TCP, UDP and other protocols. It showed ~1% tx/s improvement in small payload UDP send benchmarks using a real NIC and in a server environment and the number jumps to 2-3% for preemtible kernels. Reviewed-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/r/d8c58857113185a764927a46f4b5a058d36d3ec3.1643292455.git.asml.silence@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-27selftests/bpf: fix a clang compilation errorYonghong Song1-1/+1
When building selftests/bpf with clang make -j LLVM=1 make -C tools/testing/selftests/bpf -j LLVM=1 I hit the following compilation error: trace_helpers.c:152:9: error: variable 'found' is used uninitialized whenever 'while' loop exits because its condition is false [-Werror,-Wsometimes-uninitialized] while (fscanf(f, "%zx-%zx %s %zx %*[^\n]\n", &start, &end, buf, &base) == 4) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ trace_helpers.c:161:7: note: uninitialized use occurs here if (!found) ^~~~~ trace_helpers.c:152:9: note: remove the condition if it is always true while (fscanf(f, "%zx-%zx %s %zx %*[^\n]\n", &start, &end, buf, &base) == 4) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1 trace_helpers.c:145:12: note: initialize the variable 'found' to silence this warning bool found; ^ = false It is possible that for sane /proc/self/maps we may never hit the above issue in practice. But let us initialize variable 'found' properly to silence the compilation error. Signed-off-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20220127163726.1442032-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-27selftests, xsk: Fix bpf_res cleanup testMagnus Karlsson2-32/+50
After commit 710ad98c363a ("veth: Do not record rx queue hint in veth_xmit"), veth no longer receives traffic on the same queue as it was sent on. This breaks the bpf_res test for the AF_XDP selftests as the socket tied to queue 1 will not receive traffic anymore. Modify the test so that two sockets are tied to queue id 0 using a shared umem instead. When killing the first socket enter the second socket into the xskmap so that traffic will flow to it. This will still test that the resources are not cleaned up until after the second socket dies, without having to rely on veth supporting rx_queue hints. Reported-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20220125082945.26179-1-magnus.karlsson@gmail.com
2022-01-27Merge branch 'xsk-batching'Daniel Borkmann15-162/+330
Maciej Fijalkowski says: ==================== Unfortunately, similar scalability issues that were addressed for XDP processing in ice, exist for XDP in the zero-copy driver used by AF_XDP. Let's resolve them in mostly the same way as we did in [0] and utilize the Tx batching API from XSK buffer pool. Move the array of Tx descriptors that is used with batching approach to the XSK buffer pool. This means that future users of this API will not have to carry the array on their own side, they can simple refer to pool's tx_desc array. We also improve the Rx side where we extend ice_alloc_rx_buf_zc() to handle the ring wrap and bump Rx tail more frequently. By doing so, Rx side is adjusted to Tx and it was needed for l2fwd scenario. Here are the improvements of performance numbers that this set brings measured with xdpsock app in busy poll mode for 1 and 2 core modes. Both Tx and Rx rings were sized to 1k length and busy poll budget was 256. ---------------------------------------------------------------- | txonly: | l2fwd | rxdrop ---------------------------------------------------------------- 1C | 149% | 14% | 3% ---------------------------------------------------------------- 2C | 134% | 20% | 5% ---------------------------------------------------------------- Next step will be to introduce batching onto Rx side. v5: * collect acks * fix typos * correct comments showing cache line boundaries in ice_tx_ring struct v4 - address Alexandr's review: * new patch (2) for making sure ring size is pow(2) when attaching xsk socket * don't open code ALIGN_DOWN (patch 3) * resign from storing tx_thresh in ice_tx_ring (patch 4) * scope variables in a better way for Tx batching (patch 7) v3: * drop likely() that was wrapping napi_complete_done (patch 1) * introduce configurable Tx threshold (patch 2) * handle ring wrap on Rx side when allocating buffers (patch 3) * respect NAPI budget when cleaning Tx descriptors in ZC (patch 6) v2: * introduce new patch that resets @next_dd and @next_rs fields * use batching API for AF_XDP Tx on ice side [0]: https://lore.kernel.org/bpf/20211015162908.145341-8-anthony.l.nguyen@intel.com/ ==================== Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2022-01-27ice: xsk: Borrow xdp_tx_active logic from i40eMaciej Fijalkowski3-3/+14
One of the things that commit 5574ff7b7b3d ("i40e: optimize AF_XDP Tx completion path") introduced was the @xdp_tx_active field. Its usage from i40e can be adjusted to ice driver and give us positive performance results. If the descriptor that @next_dd points to has been sent by HW (its DD bit is set), then we are sure that at least quarter of the ring is ready to be cleaned. If @xdp_tx_active is 0 which means that related xdp_ring is not used for XDP_{TX, REDIRECT} workloads, then we know how many XSK entries should placed to completion queue, IOW walking through the ring can be skipped. Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20220125160446.78976-9-maciej.fijalkowski@intel.com
2022-01-27ice: xsk: Improve AF_XDP ZC Tx and use batching APIMaciej Fijalkowski4-101/+190
Apply the logic that was done for regular XDP from commit 9610bd988df9 ("ice: optimize XDP_TX workloads") to the ZC side of the driver. On top of that, introduce batching to Tx that is inspired by i40e's implementation with adjustments to the cleaning logic - take into the account NAPI budget in ice_clean_xdp_irq_zc(). Separating the stats structs onto separate cache lines seemed to improve the performance. Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> Link: https://lore.kernel.org/bpf/20220125160446.78976-8-maciej.fijalkowski@intel.com
2022-01-27ice: xsk: Avoid potential dead AF_XDP Tx processingMaciej Fijalkowski1-0/+2
Commit 9610bd988df9 ("ice: optimize XDP_TX workloads") introduced @next_dd and @next_rs to ice_tx_ring struct. Currently, their state is not restored in ice_clean_tx_ring(), which was not causing any troubles as the XDP rings are gone after we're done with XDP prog on interface. For upcoming usage of mentioned fields in AF_XDP, this might expose us to a potential dead Tx side. Scenario would look like following (based on xdpsock): - two xdpsock instances are spawned in Tx mode - one of them is killed - XDP prog is kept on interface due to the other xdpsock still running * this means that XDP rings stayed in place - xdpsock is launched again on same queue id that was terminated on - @next_dd and @next_rs setting is bogus, therefore transmit side is broken To protect us from the above, restore the initial @next_rs and @next_dd values when cleaning the Tx ring. Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20220125160446.78976-7-maciej.fijalkowski@intel.com
2022-01-27i40e: xsk: Move tmp desc array from driver to poolMagnus Karlsson8-30/+24
Move desc_array from the driver to the pool. The reason behind this is that we can then reuse this array as a temporary storage for descriptors in all zero-copy drivers that use the batched interface. This will make it easier to add batching to more drivers. i40e is the only driver that has a batched Tx zero-copy implementation, so no need to touch any other driver. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> Link: https://lore.kernel.org/bpf/20220125160446.78976-6-maciej.fijalkowski@intel.com
2022-01-27ice: Make Tx threshold dependent on ring lengthMaciej Fijalkowski4-9/+12
XDP_TX workloads use a concept of Tx threshold that indicates the interval of setting RS bit on descriptors which in turn tells the HW to generate an interrupt to signal the completion of Tx on HW side. It is currently based on a constant value of 32 which might not work out well for various sizes of ring combined with for example batch size that can be set via SO_BUSY_POLL_BUDGET. Internal tests based on AF_XDP showed that most convenient setup of mentioned threshold is when it is equal to quarter of a ring length. Make use of recently introduced ICE_RING_QUARTER macro and use this value as a substitute for ICE_TX_THRESH. Align also ethtool -G callback so that next_dd/next_rs fields are up to date in terms of the ring size. Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20220125160446.78976-5-maciej.fijalkowski@intel.com
2022-01-27ice: xsk: Handle SW XDP ring wrap and bump tail more oftenMaciej Fijalkowski2-20/+81
Currently, if ice_clean_rx_irq_zc() processed the whole ring and next_to_use != 0, then ice_alloc_rx_buf_zc() would not refill the whole ring even if the XSK buffer pool would have enough free entries (either from fill ring or the internal recycle mechanism) - it is because ring wrap is not handled. Improve the logic in ice_alloc_rx_buf_zc() to address the problem above. Do not clamp the count of buffers that is passed to xsk_buff_alloc_batch() in case when next_to_use + buffer count >= rx_ring->count, but rather split it and have two calls to the mentioned function - one for the part up until the wrap and one for the part after the wrap. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com> Link: https://lore.kernel.org/bpf/20220125160446.78976-4-maciej.fijalkowski@intel.com