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* libbpf: fix ring_buffer__consume_n() return result logicAndrii Nakryiko2024-05-021-1/+1
| | | | | | | | | | | | Add INT_MAX check to ring_buffer__consume_n(). We do the similar check to handle int return result of all these ring buffer APIs in other APIs and ring_buffer__consume_n() is missing one. This patch fixes this omission. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20240430201952.888293-2-andrii@kernel.org Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
* libbpf: fix potential overflow in ring__consume_n()Andrii Nakryiko2024-05-021-1/+1
| | | | | | | | | | | | | ringbuf_process_ring() return int64_t, while ring__consume_n() assigns it to int. It's highly unlikely, but possible for ringbuf_process_ring() to return value larger than INT_MAX, so use int64_t. ring__consume_n() does check INT_MAX before returning int result to the user. Fixes: 4d22ea94ea33 ("libbpf: Add ring__consume_n / ring_buffer__consume_n") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20240430201952.888293-1-andrii@kernel.org Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
* libbpf: Add ring__consume_n / ring_buffer__consume_nAndrea Righi2024-04-061-3/+35
| | | | | | | | | | | Introduce a new API to consume items from a ring buffer, limited to a specified amount, and return to the caller the actual number of items consumed. Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/lkml/20240310154726.734289-1-andrea.righi@canonical.com/T Link: https://lore.kernel.org/bpf/20240406092005.92399-4-andrea.righi@canonical.com
* libbpf: ringbuf: Allow to consume up to a certain amount of itemsAndrea Righi2024-04-061-7/+12
| | | | | | | | | | | | | | In some cases, instead of always consuming all items from ring buffers in a greedy way, we may want to consume up to a certain amount of items, for example when we need to copy items from the BPF ring buffer to a limited user buffer. This change allows to set an upper limit to the amount of items consumed from one or more ring buffers. Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20240406092005.92399-3-andrea.righi@canonical.com
* libbpf: Add ring__consumeMartin Kelly2023-09-251-0/+11
| | | | | | | | | Add ring__consume to consume a single ringbuffer, analogous to ring_buffer__consume. Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230925215045.2375758-14-martin.kelly@crowdstrike.com
* libbpf: Add ring__map_fdMartin Kelly2023-09-251-0/+5
| | | | | | | | | Add ring__map_fd to get the file descriptor underlying a given ringbuffer. Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230925215045.2375758-12-martin.kelly@crowdstrike.com
* libbpf: Add ring__sizeMartin Kelly2023-09-251-0/+5
| | | | | | | | Add ring__size to get the total size of a given ringbuffer. Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230925215045.2375758-10-martin.kelly@crowdstrike.com
* libbpf: Add ring__avail_data_sizeMartin Kelly2023-09-251-0/+9
| | | | | | | | | | | Add ring__avail_data_size for querying the currently available data in the ringbuffer, similar to the BPF_RB_AVAIL_DATA flag in bpf_ringbuf_query. This is racy during ongoing operations but is still useful for overall information on how a ringbuffer is behaving. Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230925215045.2375758-8-martin.kelly@crowdstrike.com
* libbpf: Add ring__producer_pos, ring__consumer_posMartin Kelly2023-09-251-0/+14
| | | | | | | | | Add APIs to get the producer and consumer position for a given ringbuffer. Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230925215045.2375758-6-martin.kelly@crowdstrike.com
* libbpf: Add ring_buffer__ringMartin Kelly2023-09-251-0/+8
| | | | | | | | | Add a new function ring_buffer__ring, which exposes struct ring * to the user, representing a single ringbuffer. Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230925215045.2375758-4-martin.kelly@crowdstrike.com
* libbpf: Switch rings to array of pointersMartin Kelly2023-09-251-8/+12
| | | | | | | | | | | | | Switch rb->rings to be an array of pointers instead of a contiguous block. This allows for each ring pointer to be stable after ring_buffer__add is called, which allows us to expose struct ring * to the user without gotchas. Without this change, the realloc in ring_buffer__add could invalidate a struct ring *, making it unsafe to give to the user. Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230925215045.2375758-3-martin.kelly@crowdstrike.com
* libbpf: Refactor cleanup in ring_buffer__addMartin Kelly2023-09-251-6/+9
| | | | | | | | | | | Refactor the cleanup code in ring_buffer__add to use a unified err_out label. This reduces code duplication, as well as plugging a potential leak if mmap_sz != (__u64)(size_t)mmap_sz (currently this would miss unmapping tmp because ringbuf_unmap_ring isn't called). Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230925215045.2375758-2-martin.kelly@crowdstrike.com
* libbpf: Use bpf_{btf,link,map,prog}_get_info_by_fd()Ilya Leoshkevich2023-02-161-2/+2
| | | | | | | | Use the new type-safe wrappers around bpf_obj_get_info_by_fd(). Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230214231221.249277-3-iii@linux.ibm.com
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-11-291-6/+20
|\ | | | | | | | | | | | | | | | | tools/lib/bpf/ringbuf.c 927cbb478adf ("libbpf: Handle size overflow for ringbuf mmap") b486d19a0ab0 ("libbpf: checkpatch: Fixed code alignments in ringbuf.c") https://lore.kernel.org/all/20221121122707.44d1446a@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * libbpf: Check the validity of size in user_ring_buffer__reserve()Hou Tao2022-11-171-0/+4
| | | | | | | | | | | | | | | | | | | | | | The top two bits of size are used as busy and discard flags, so reject the reservation that has any of these special bits in the size. With the addition of validity check, these is also no need to check whether or not total_size is overflowed. Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221116072351.1168938-5-houtao@huaweicloud.com
| * libbpf: Handle size overflow for user ringbuf mmapHou Tao2022-11-171-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | Similar with the overflow problem on ringbuf mmap, in user_ringbuf_map() 2 * max_entries may overflow u32 when mapping writeable region. Fixing it by casting the size of writable mmap region into a __u64 and checking whether or not there will be overflow during mmap. Fixes: b66ccae01f1d ("bpf: Add libbpf logic for user-space ring buffer") Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221116072351.1168938-4-houtao@huaweicloud.com
| * libbpf: Handle size overflow for ringbuf mmapHou Tao2022-11-171-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The maximum size of ringbuf is 2GB on x86-64 host, so 2 * max_entries will overflow u32 when mapping producer page and data pages. Only casting max_entries to size_t is not enough, because for 32-bits application on 64-bits kernel the size of read-only mmap region also could overflow size_t. So fixing it by casting the size of read-only mmap region into a __u64 and checking whether or not there will be overflow during mmap. Fixes: bf99c936f947 ("libbpf: Add BPF ring buffer support") Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20221116072351.1168938-3-houtao@huaweicloud.com
* | libbpf: checkpatch: Fixed code alignments in ringbuf.cKang Minchul2022-11-141-2/+2
|/ | | | | | | | | Fixed some checkpatch issues in ringbuf.c Signed-off-by: Kang Minchul <tegongkang@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20221113190648.38556-4-tegongkang@gmail.com
* bpf: Add libbpf logic for user-space ring bufferDavid Vernet2022-09-211-0/+271
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that all of the logic is in place in the kernel to support user-space produced ring buffers, we can add the user-space logic to libbpf. This patch therefore adds the following public symbols to libbpf: struct user_ring_buffer * user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts); void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size); void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb, __u32 size, int timeout_ms); void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample); void user_ring_buffer__discard(struct user_ring_buffer *rb, void user_ring_buffer__free(struct user_ring_buffer *rb); A user-space producer must first create a struct user_ring_buffer * object with user_ring_buffer__new(), and can then reserve samples in the ring buffer using one of the following two symbols: void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size); void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb, __u32 size, int timeout_ms); With user_ring_buffer__reserve(), a pointer to a 'size' region of the ring buffer will be returned if sufficient space is available in the buffer. user_ring_buffer__reserve_blocking() provides similar semantics, but will block for up to 'timeout_ms' in epoll_wait if there is insufficient space in the buffer. This function has the guarantee from the kernel that it will receive at least one event-notification per invocation to bpf_ringbuf_drain(), provided that at least one sample is drained, and the BPF program did not pass the BPF_RB_NO_WAKEUP flag to bpf_ringbuf_drain(). Once a sample is reserved, it must either be committed to the ring buffer with user_ring_buffer__submit(), or discarded with user_ring_buffer__discard(). Signed-off-by: David Vernet <void@manifault.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220920000100.477320-4-void@manifault.com
* libbpf: Streamline error reporting for high-level APIsAndrii Nakryiko2021-05-251-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement changes to error reporting for high-level libbpf APIs to make them less surprising and less error-prone to users: - in all the cases when error happens, errno is set to an appropriate error value; - in libbpf 1.0 mode, all pointer-returning APIs return NULL on error and error code is communicated through errno; this applies both to APIs that already returned NULL before (so now they communicate more detailed error codes), as well as for many APIs that used ERR_PTR() macro and encoded error numbers as fake pointers. - in legacy (default) mode, those APIs that were returning ERR_PTR(err), continue doing so, but still set errno. With these changes, errno can be always used to extract actual error, regardless of legacy or libbpf 1.0 modes. This is utilized internally in libbpf in places where libbpf uses it's own high-level APIs. libbpf_get_error() is adapted to handle both cases completely transparently to end-users (and is used by libbpf consistently as well). More context, justification, and discussion can be found in "Libbpf: the road to v1.0" document ([0]). [0] https://docs.google.com/document/d/1UyjTZuPFWiPFyKk1tV5an11_iaRuec6U-ZESZ54nNTY Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20210525035935.1461796-5-andrii@kernel.org
* libbpf: Fix signed overflow in ringbuf_process_ringBrendan Jackman2021-05-031-9/+21
| | | | | | | | | | | | | | | | | One of our benchmarks running in (Google-internal) CI pushes data through the ringbuf faster htan than userspace is able to consume it. In this case it seems we're actually able to get >INT_MAX entries in a single ring_buffer__consume() call. ASAN detected that cnt overflows in this case. Fix by using 64-bit counter internally and then capping the result to INT_MAX before converting to the int return type. Do the same for the ring_buffer__poll(). Fixes: bf99c936f947 (libbpf: Add BPF ring buffer support) Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210429130510.1621665-1-jackmanb@google.com
* libbpf: Fix bail out from 'ringbuf_process_ring()' on errorPedro Tammela2021-03-251-1/+1
| | | | | | | | | | | | | | The current code bails out with negative and positive returns. If the callback returns a positive return code, 'ring_buffer__consume()' and 'ring_buffer__poll()' will return a spurious number of records consumed, but mostly important will continue the processing loop. This patch makes positive returns from the callback a no-op. Fixes: bf99c936f947 ("libbpf: Add BPF ring buffer support") Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210325150115.138750-1-pctammela@mojatatu.com
* Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski2020-12-141-0/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf-next 2020-12-14 1) Expose bpf_sk_storage_*() helpers to iterator programs, from Florent Revest. 2) Add AF_XDP selftests based on veth devs to BPF selftests, from Weqaar Janjua. 3) Support for finding BTF based kernel attach targets through libbpf's bpf_program__set_attach_target() API, from Andrii Nakryiko. 4) Permit pointers on stack for helper calls in the verifier, from Yonghong Song. 5) Fix overflows in hash map elem size after rlimit removal, from Eric Dumazet. 6) Get rid of direct invocation of llc in BPF selftests, from Andrew Delgadillo. 7) Fix xsk_recvmsg() to reorder socket state check before access, from Björn Töpel. 8) Add new libbpf API helper to retrieve ring buffer epoll fd, from Brendan Jackman. 9) Batch of minor BPF selftest improvements all over the place, from Florian Lehner, KP Singh, Jiri Olsa and various others. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (31 commits) selftests/bpf: Add a test for ptr_to_map_value on stack for helper access bpf: Permits pointers on stack for helper calls libbpf: Expose libbpf ring_buffer epoll_fd selftests/bpf: Add set_attach_target() API selftest for module target libbpf: Support modules in bpf_program__set_attach_target() API selftests/bpf: Silence ima_setup.sh when not running in verbose mode. selftests/bpf: Drop the need for LLVM's llc selftests/bpf: fix bpf_testmod.ko recompilation logic samples/bpf: Fix possible hang in xdpsock with multiple threads selftests/bpf: Make selftest compilation work on clang 11 selftests/bpf: Xsk selftests - adding xdpxceiver to .gitignore selftests/bpf: Drop tcp-{client,server}.py from Makefile selftests/bpf: Xsk selftests - Bi-directional Sockets - SKB, DRV selftests/bpf: Xsk selftests - Socket Teardown - SKB, DRV selftests/bpf: Xsk selftests - DRV POLL, NOPOLL selftests/bpf: Xsk selftests - SKB POLL, NOPOLL selftests/bpf: Xsk selftests framework bpf: Only provide bpf_sock_from_file with CONFIG_NET bpf: Return -ENOTSUPP when attaching to non-kernel BTF xsk: Validate socket state in xsk_recvmsg, prior touching socket members ... ==================== Link: https://lore.kernel.org/r/20201214214316.20642-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * libbpf: Expose libbpf ring_buffer epoll_fdBrendan Jackman2020-12-141-0/+6
| | | | | | | | | | | | | | | | | | | | This provides a convenient perf ringbuf -> libbpf ringbuf migration path for users of external polling systems. It is analogous to perf_buffer__epoll_fd. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20201214113812.305274-1-jackmanb@google.com
* | libbpf: Fix ring_buffer__poll() to return number of consumed samplesAndrii Nakryiko2020-12-011-1/+1
|/ | | | | | | | | | | | Fix ring_buffer__poll() to return the number of non-discarded records consumed, just like its documentation states. It's also consistent with ring_buffer__consume() return. Fix up selftests with wrong expected results. Fixes: bf99c936f947 ("libbpf: Add BPF ring buffer support") Fixes: cb1c9ddd5525 ("selftests/bpf: Add BPF ringbuf selftests") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201130223336.904192-1-andrii@kernel.org
* libbpf: Centralize poisoning and poison reallocarray()Andrii Nakryiko2020-08-181-3/+0
| | | | | | | | | | | | Most of libbpf source files already include libbpf_internal.h, so it's a good place to centralize identifier poisoning. So move kernel integer type poisoning there. And also add reallocarray to a poison list to prevent accidental use of it. libbpf_reallocarray() should be used universally instead. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200819013607.3607269-4-andriin@fb.com
* libbpf: Remove any use of reallocarray() in libbpfAndrii Nakryiko2020-08-181-3/+2
| | | | | | | | | | | | | | | | | Re-implement glibc's reallocarray() for libbpf internal-only use. reallocarray(), unfortunately, is not available in all versions of glibc, so requires extra feature detection and using reallocarray() stub from <tools/libc_compat.h> and COMPAT_NEED_REALLOCARRAY. All this complicates build of libbpf unnecessarily and is just a maintenance burden. Instead, it's trivial to implement libbpf-specific internal version and use it throughout libbpf. Which is what this patch does, along with converting some realloc() uses that should really have been reallocarray() in the first place. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200819013607.3607269-2-andriin@fb.com
* libbpf: Add _GNU_SOURCE for reallocarray to ringbuf.cAndrii Nakryiko2020-06-011-0/+3
| | | | | | | | | | | | On systems with recent enough glibc, reallocarray compat won't kick in, so reallocarray() itself has to come from stdlib.h include. But _GNU_SOURCE is necessary to enable it. So add it. Fixes: bf99c936f947 ("libbpf: Add BPF ring buffer support") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200601202601.2139477-1-andriin@fb.com
* libbpf: Add BPF ring buffer supportAndrii Nakryiko2020-06-011-0/+285
Declaring and instantiating BPF ring buffer doesn't require any changes to libbpf, as it's just another type of maps. So using existing BTF-defined maps syntax with __uint(type, BPF_MAP_TYPE_RINGBUF) and __uint(max_elements, <size-of-ring-buf>) is all that's necessary to create and use BPF ring buffer. This patch adds BPF ring buffer consumer to libbpf. It is very similar to perf_buffer implementation in terms of API, but also attempts to fix some minor problems and inconveniences with existing perf_buffer API. ring_buffer support both single ring buffer use case (with just using ring_buffer__new()), as well as allows to add more ring buffers, each with its own callback and context. This allows to efficiently poll and consume multiple, potentially completely independent, ring buffers, using single epoll instance. The latter is actually a problem in practice for applications that are using multiple sets of perf buffers. They have to create multiple instances for struct perf_buffer and poll them independently or in a loop, each approach having its own problems (e.g., inability to use a common poll timeout). struct ring_buffer eliminates this problem by aggregating many independent ring buffer instances under the single "ring buffer manager". Second, perf_buffer's callback can't return error, so applications that need to stop polling due to error in data or data signalling the end, have to use extra mechanisms to signal that polling has to stop. ring_buffer's callback can return error, which will be passed through back to user code and can be acted upon appropariately. Two APIs allow to consume ring buffer data: - ring_buffer__poll(), which will wait for data availability notification and will consume data only from reported ring buffer(s); this API allows to efficiently use resources by reading data only when it becomes available; - ring_buffer__consume(), will attempt to read new records regardless of data availablity notification sub-system. This API is useful for cases when lowest latency is required, in expense of burning CPU resources. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200529075424.3139988-3-andriin@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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