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* selftests, xsk: Fix rx_full stats testMagnus Karlsson2022-01-241-1/+4
| | | | | | | | | | | | Fix the rx_full stats test so that it correctly reports pass even when the fill ring is not full of buffers. Fixes: 872a1184dbf2 ("selftests: xsk: Put the same buffer only once in the fill ring") Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Link: https://lore.kernel.org/bpf/20220121123508.12759-1-magnus.karlsson@gmail.com
* bpf: Fix flexible_array.cocci warningskernel test robot2022-01-241-1/+1
| | | | | | | | | | | | | | | | | Zero-length and one-element arrays are deprecated, see: Documentation/process/deprecated.rst Flexible-array members should be used instead. Generated by: scripts/coccinelle/misc/flexible_array.cocci Fixes: c1ff181ffabc ("selftests/bpf: Extend kfunc selftests") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: kernel test robot <lkp@intel.com> Signed-off-by: Julia Lawall <julia.lawall@inria.fr> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/alpine.DEB.2.22.394.2201221206320.12220@hadrien
* Merge branch 'mvneta: introduce XDP multi-buffer support'Alexei Starovoitov2022-01-2129-201/+1326
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lorenzo Bianconi says: ==================== This series introduces XDP frags support. The mvneta driver is the first to support these new "non-linear" xdp_{buff,frame}. Reviewers please focus on how these new types of xdp_{buff,frame} packets traverse the different layers and the layout design. It is on purpose that BPF-helpers are kept simple, as we don't want to expose the internal layout to allow later changes. The main idea for the new XDP frags layout is to reuse the same structure used for non-linear SKB. This rely on the "skb_shared_info" struct at the end of the first buffer to link together subsequent buffers. Keeping the layout compatible with SKBs is also done to ease and speedup creating a SKB from an xdp_{buff,frame}. Converting xdp_frame to SKB and deliver it to the network stack is shown in patch 05/18 (e.g. cpumaps). A frags bit (XDP_FLAGS_HAS_FRAGS) has been introduced in the flags field of xdp_{buff,frame} structure to notify the bpf/network layer if this is a non-linear xdp frame (XDP_FLAGS_HAS_FRAGS set) or not (XDP_FLAGS_HAS_FRAGS not set). The frags bit will be set by a xdp frags capable driver only for non-linear frames maintaining the capability to receive linear frames without any extra cost since the skb_shared_info structure at the end of the first buffer will be initialized only if XDP_FLAGS_HAS_FRAGS bit is set. Moreover the flags field in xdp_{buff,frame} will be reused even for xdp rx csum offloading in future series. Typical use cases for this series are: - Jumbo-frames - Packet header split (please see Google’s use-case @ NetDevConf 0x14, [0]) - TSO/GRO for XDP_REDIRECT The three following ebpf helpers (and related selftests) has been introduced: - bpf_xdp_load_bytes: This helper is provided as an easy way to load data from a xdp buffer. It can be used to load len bytes from offset from the frame associated to xdp_md, into the buffer pointed by buf. - bpf_xdp_store_bytes: Store len bytes from buffer buf into the frame associated to xdp_md, at offset. - bpf_xdp_get_buff_len: Return the total frame size (linear + paged parts) bpf_xdp_adjust_tail and bpf_xdp_copy helpers have been modified to take into account non-linear xdp frames. Moreover, similar to skb_header_pointer, we introduced bpf_xdp_pointer utility routine to return a pointer to a given position in the xdp_buff if the requested area (offset + len) is contained in a contiguous memory area otherwise it must be copied in a bounce buffer provided by the caller running bpf_xdp_copy_buf(). BPF_F_XDP_HAS_FRAGS flag has been introduced to notify the kernel the eBPF program fully support xdp frags. SEC("xdp.frags"), SEC_DEF("xdp.frags/devmap") and SEC_DEF("xdp.frags/cpumap") have been introduced to declare xdp frags support. The NIC driver is expected to reject an eBPF program if it is running in XDP frags mode and the program does not support XDP frags. In the same way it is not possible to mix XDP frags and XDP legacy programs in a CPUMAP/DEVMAP or tailcall a XDP frags/legacy program from a legacy/frags one. More info about the main idea behind this approach can be found here [1][2]. Changes since v22: - remove leftover CHECK macro usage - reintroduce SEC_XDP_FRAGS flag in sec_def_flags - rename xdp multi_frags in xdp frags - do not report xdp_frags support in fdinfo Changes since v21: - rename *_mb in *_frags: e.g: s/xdp_buff_is_mb/xdp_buff_has_frags - rely on ASSERT_* and not on CHECK in bpf_xdp_load_bytes/bpf_xdp_store_bytes self-tests - change new multi.frags SEC definitions to use the following schema: prog_type.prog_flags/attach_place - get rid of unnecessary properties in new multi.frags SEC definitions - rebase on top of bpf-next Changes since v20: - rebase to current bpf-next Changes since v19: - do not run deprecated bpf_prog_load() - rely on skb_frag_size_add/skb_frag_size_sub in bpf_xdp_mb_increase_tail/bpf_xdp_mb_shrink_tail - rely on sinfo->nr_frags in bpf_xdp_mb_shrink_tail to check if the frame has been shrunk to a single-buffer one - allow XDP_REDIRECT of a xdp-mb frame into a CPUMAP Changes since v18: - fix bpf_xdp_copy_buf utility routine when we want to load/store data contained in frag<n> - add a selftest for bpf_xdp_load_bytes/bpf_xdp_store_bytes when the caller accesses data contained in frag<n> and frag<n+1> Changes since v17: - rework bpf_xdp_copy to squash base and frag management - remove unused variable in bpf_xdp_mb_shrink_tail() - move bpf_xdp_copy_buf() out of bpf_xdp_pointer() - add sanity check for len in bpf_xdp_pointer() - remove EXPORT_SYMBOL for __xdp_return() - introduce frag_size field in xdp_rxq_info to let the driver specify max value for xdp fragments. frag_size set to 0 means the tail increase of last the fragment is not supported. Changes since v16: - do not allow tailcalling a xdp multi-buffer/legacy program from a legacy/multi-buff one. - do not allow mixing xdp multi-buffer and xdp legacy programs in a CPUMAP/DEVMAP - add selftests for CPUMAP/DEVMAP xdp mb compatibility - disable XDP_REDIRECT for xdp multi-buff for the moment - set max offset value to 0xffff in bpf_xdp_pointer - use ARG_PTR_TO_UNINIT_MEM and ARG_CONST_SIZE for arg3_type and arg4_type of bpf_xdp_store_bytes/bpf_xdp_load_bytes Changes since v15: - let the verifier check buf is not NULL in bpf_xdp_load_bytes/bpf_xdp_store_bytes helpers - return an error if offset + length is over frame boundaries in bpf_xdp_pointer routine - introduce BPF_F_XDP_MB flag for bpf_attr to notify the kernel the eBPF program fully supports xdp multi-buffer. - reject a non XDP multi-buffer program if the driver is running in XDP multi-buffer mode. Changes since v14: - intrudce bpf_xdp_pointer utility routine and bpf_xdp_load_bytes/bpf_xdp_store_bytes helpers - drop bpf_xdp_adjust_data helper - drop xdp_frags_truesize in skb_shared_info - explode bpf_xdp_mb_adjust_tail in bpf_xdp_mb_increase_tail and bpf_xdp_mb_shrink_tail Changes since v13: - use u32 for xdp_buff/xdp_frame flags field - rename xdp_frags_tsize in xdp_frags_truesize - fixed comments Changes since v12: - fix bpf_xdp_adjust_data helper for single-buffer use case - return -EFAULT in bpf_xdp_adjust_{head,tail} in case the data pointers are not properly reset - collect ACKs from John Changes since v11: - add missing static to bpf_xdp_get_buff_len_proto structure - fix bpf_xdp_adjust_data helper when offset is smaller than linear area length. Changes since v10: - move xdp->data to the requested payload offset instead of to the beginning of the fragment in bpf_xdp_adjust_data() Changes since v9: - introduce bpf_xdp_adjust_data helper and related selftest - add xdp_frags_size and xdp_frags_tsize fields in skb_shared_info - introduce xdp_update_skb_shared_info utility routine in ordere to not reset frags array in skb_shared_info converting from a xdp_buff/xdp_frame to a skb - simplify bpf_xdp_copy routine Changes since v8: - add proper dma unmapping if XDP_TX fails on mvneta for a xdp multi-buff - switch back to skb_shared_info implementation from previous xdp_shared_info one - avoid using a bietfield in xdp_buff/xdp_frame since it introduces performance regressions. Tested now on 10G NIC (ixgbe) to verify there are no performance penalties for regular codebase - add bpf_xdp_get_buff_len helper and remove frame_length field in xdp ctx - add data_len field in skb_shared_info struct - introduce XDP_FLAGS_FRAGS_PF_MEMALLOC flag Changes since v7: - rebase on top of bpf-next - fix sparse warnings - improve comments for frame_length in include/net/xdp.h Changes since v6: - the main difference respect to previous versions is the new approach proposed by Eelco to pass full length of the packet to eBPF layer in XDP context - reintroduce multi-buff support to eBPF kself-tests - reintroduce multi-buff support to bpf_xdp_adjust_tail helper - introduce multi-buffer support to bpf_xdp_copy helper - rebase on top of bpf-next Changes since v5: - rebase on top of bpf-next - initialize mb bit in xdp_init_buff() and drop per-driver initialization - drop xdp->mb initialization in xdp_convert_zc_to_xdp_frame() - postpone introduction of frame_length field in XDP ctx to another series - minor changes Changes since v4: - rebase ontop of bpf-next - introduce xdp_shared_info to build xdp multi-buff instead of using the skb_shared_info struct - introduce frame_length in xdp ctx - drop previous bpf helpers - fix bpf_xdp_adjust_tail for xdp multi-buff - introduce xdp multi-buff self-tests for bpf_xdp_adjust_tail - fix xdp_return_frame_bulk for xdp multi-buff Changes since v3: - rebase ontop of bpf-next - add patch 10/13 to copy back paged data from a xdp multi-buff frame to userspace buffer for xdp multi-buff selftests Changes since v2: - add throughput measurements - drop bpf_xdp_adjust_mb_header bpf helper - introduce selftest for xdp multibuffer - addressed comments on bpf_xdp_get_frags_count - introduce xdp multi-buff support to cpumaps Changes since v1: - Fix use-after-free in xdp_return_{buff/frame} - Introduce bpf helpers - Introduce xdp_mb sample program - access skb_shared_info->nr_frags only on the last fragment Changes since RFC: - squash multi-buffer bit initialization in a single patch - add mvneta non-linear XDP buff support for tx side [0] https://netdevconf.info/0x14/session.html?talk-the-path-to-tcp-4k-mtu-and-rx-zerocopy [1] https://github.com/xdp-project/xdp-project/blob/master/areas/core/xdp-multi-buffer01-design.org [2] https://netdevconf.info/0x14/session.html?tutorial-add-XDP-support-to-a-NIC-driver (XDPmulti-buffers section) Eelco Chaudron (3): bpf: add frags support to the bpf_xdp_adjust_tail() API bpf: add frags support to xdp copy helpers bpf: selftests: update xdp_adjust_tail selftest to include xdp frags Lorenzo Bianconi (19): net: skbuff: add size metadata to skb_shared_info for xdp xdp: introduce flags field in xdp_buff/xdp_frame net: mvneta: update frags bit before passing the xdp buffer to eBPF layer net: mvneta: simplify mvneta_swbm_add_rx_fragment management net: xdp: add xdp_update_skb_shared_info utility routine net: marvell: rely on xdp_update_skb_shared_info utility routine xdp: add frags support to xdp_return_{buff/frame} net: mvneta: add frags support to XDP_TX bpf: introduce BPF_F_XDP_HAS_FRAGS flag in prog_flags loading the ebpf program net: mvneta: enable jumbo frames if the loaded XDP program support frags bpf: introduce bpf_xdp_get_buff_len helper bpf: move user_size out of bpf_test_init bpf: introduce frags support to bpf_prog_test_run_xdp() bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature libbpf: Add SEC name for xdp frags programs net: xdp: introduce bpf_xdp_pointer utility routine bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest bpf: selftests: add CPUMAP/DEVMAP selftests for xdp frags xdp: disable XDP_REDIRECT for xdp frags ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * xdp: disable XDP_REDIRECT for xdp fragsLorenzo Bianconi2022-01-211-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | XDP_REDIRECT is not fully supported yet for xdp frags since not all XDP capable drivers can map non-linear xdp_frame in ndo_xdp_xmit so disable it for the moment. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/0da25e117d0e2673f5d0ce6503393c55c6fb1be9.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: selftests: add CPUMAP/DEVMAP selftests for xdp fragsLorenzo Bianconi2022-01-216-1/+185
| | | | | | | | | | | | | | | | | | | | | | Verify compatibility checks attaching a XDP frags program to a CPUMAP/DEVMAP Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/d94b4d35adc1e42c9ca5004e6b2cdfd75992304d.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftestLorenzo Bianconi2022-01-212-0/+146
| | | | | | | | | | | | | | | | | | | | | | Introduce kernel selftest for new bpf_xdp_{load,store}_bytes helpers. and bpf_xdp_pointer/bpf_xdp_copy_buf utility routines. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/2c99ae663a5dcfbd9240b1d0489ad55dea4f4601.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * net: xdp: introduce bpf_xdp_pointer utility routineLorenzo Bianconi2022-01-213-38/+174
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similar to skb_header_pointer, introduce bpf_xdp_pointer utility routine to return a pointer to a given position in the xdp_buff if the requested area (offset + len) is contained in a contiguous memory area otherwise it will be copied in a bounce buffer provided by the caller. Similar to the tc counterpart, introduce the two following xdp helpers: - bpf_xdp_load_bytes - bpf_xdp_store_bytes Reviewed-by: Eelco Chaudron <echaudro@redhat.com> Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/ab285c1efdd5b7a9d361348b1e7d3ef49f6382b3.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: generalise tail call map compatibility checkToke Hoiland-Jorgensen2022-01-216-40/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The check for tail call map compatibility ensures that tail calls only happen between maps of the same type. To ensure backwards compatibility for XDP frags we need a similar type of check for cpumap and devmap programs, so move the state from bpf_array_aux into bpf_map, add xdp_has_frags to the check, and apply the same check to cpumap and devmap. Acked-by: John Fastabend <john.fastabend@gmail.com> Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Toke Hoiland-Jorgensen <toke@redhat.com> Link: https://lore.kernel.org/r/f19fd97c0328a39927f3ad03e1ca6b43fd53cdfd.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * libbpf: Add SEC name for xdp frags programsLorenzo Bianconi2022-01-211-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce support for the following SEC entries for XDP frags property: - SEC("xdp.frags") - SEC("xdp.frags/devmap") - SEC("xdp.frags/cpumap") Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/af23b6e4841c171ad1af01917839b77847a4bc27.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: selftests: update xdp_adjust_tail selftest to include xdp fragsEelco Chaudron2022-01-213-7/+160
| | | | | | | | | | | | | | | | | | | | | | | | | | This change adds test cases for the xdp frags scenarios when shrinking and growing. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Eelco Chaudron <echaudro@redhat.com> Link: https://lore.kernel.org/r/d2e6a0ebc52db6f89e62b9befe045032e5e0a5fe.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signatureLorenzo Bianconi2022-01-211-9/+39
| | | | | | | | | | | | | | | | | | | | | | introduce xdp_shared_info pointer in bpf_test_finish signature in order to copy back paged data from a xdp frags frame to userspace buffer Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/c803673798c786f915bcdd6c9338edaa9740d3d6.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: introduce frags support to bpf_prog_test_run_xdp()Lorenzo Bianconi2022-01-211-13/+45
| | | | | | | | | | | | | | | | | | | | | | | | Introduce the capability to allocate a xdp frags in bpf_prog_test_run_xdp routine. This is a preliminary patch to introduce the selftests for new xdp frags ebpf helpers Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/b7c0e425a9287f00f601c4fc0de54738ec6ceeea.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: move user_size out of bpf_test_initLorenzo Bianconi2022-01-211-6/+7
| | | | | | | | | | | | | | | | | | | | | | Rely on data_size_in in bpf_test_init routine signature. This is a preliminary patch to introduce xdp frags selftest Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/6b48d38ed3d60240d7d6bb15e6fa7fabfac8dfb2.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: add frags support to xdp copy helpersEelco Chaudron2022-01-214-36/+137
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds support for frags for the following helpers: - bpf_xdp_output() - bpf_perf_event_output() Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Eelco Chaudron <echaudro@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/340b4a99cdc24337b40eaf8bb597f9f9e7b0373e.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: add frags support to the bpf_xdp_adjust_tail() APIEelco Chaudron2022-01-214-8/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This change adds support for tail growing and shrinking for XDP frags. When called on a non-linear packet with a grow request, it will work on the last fragment of the packet. So the maximum grow size is the last fragments tailroom, i.e. no new buffer will be allocated. A XDP frags capable driver is expected to set frag_size in xdp_rxq_info data structure to notify the XDP core the fragment size. frag_size set to 0 is interpreted by the XDP core as tail growing is not allowed. Introduce __xdp_rxq_info_reg utility routine to initialize frag_size field. When shrinking, it will work from the last fragment, all the way down to the base buffer depending on the shrinking size. It's important to mention that once you shrink down the fragment(s) are freed, so you can not grow again to the original size. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Eelco Chaudron <echaudro@redhat.com> Link: https://lore.kernel.org/r/eabda3485dda4f2f158b477729337327e609461d.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: introduce bpf_xdp_get_buff_len helperLorenzo Bianconi2022-01-214-0/+43
| | | | | | | | | | | | | | | | | | | | | | Introduce bpf_xdp_get_buff_len helper in order to return the xdp buffer total size (linear and paged area) Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/aac9ac3504c84026cf66a3c71b7c5ae89bc991be.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * net: mvneta: enable jumbo frames if the loaded XDP program support fragsLorenzo Bianconi2022-01-211-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | Enable the capability to receive jumbo frames even if the interface is running in XDP mode if the loaded program declare to properly support xdp frags. At same time reject a xdp program not supporting xdp frags if the driver is running in xdp frags mode. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/6909f81a3cbb8fb6b88e914752c26395771b882a.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: introduce BPF_F_XDP_HAS_FRAGS flag in prog_flags loading the ebpf programLorenzo Bianconi2022-01-214-1/+14
| | | | | | | | | | | | | | | | | | | | | | Introduce BPF_F_XDP_HAS_FRAGS and the related field in bpf_prog_aux in order to notify the driver the loaded program support xdp frags. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/db2e8075b7032a356003f407d1b0deb99adaa0ed.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * net: mvneta: add frags support to XDP_TXLorenzo Bianconi2022-01-211-36/+76
| | | | | | | | | | | | | | | | | | | | | | Introduce the capability to map non-linear xdp buffer running mvneta_xdp_submit_frame() for XDP_TX and XDP_REDIRECT Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/5d46ab63870ffe96fb95e6075a7ff0c81ef6424d.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * xdp: add frags support to xdp_return_{buff/frame}Lorenzo Bianconi2022-01-212-3/+69
| | | | | | | | | | | | | | | | | | | | | | | | Take into account if the received xdp_buff/xdp_frame is non-linear recycling/returning the frame memory to the allocator or into xdp_frame_bulk. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/a961069febc868508ce1bdf5e53a343eb4e57cb2.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * net: marvell: rely on xdp_update_skb_shared_info utility routineLorenzo Bianconi2022-01-211-13/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Rely on xdp_update_skb_shared_info routine in order to avoid resetting frags array in skb_shared_info structure building the skb in mvneta_swbm_build_skb(). Frags array is expected to be initialized by the receiving driver building the xdp_buff and here we just need to update memory metadata. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/e0dad97f5d02b13f189f99f1e5bc8e61bef73412.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * net: xdp: add xdp_update_skb_shared_info utility routineLorenzo Bianconi2022-01-212-1/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce xdp_update_skb_shared_info routine to update frags array metadata in skb_shared_info data structure converting to a skb from a xdp_buff or xdp_frame. According to the current skb_shared_info architecture in xdp_frame/xdp_buff and to the xdp frags support, there is no need to run skb_add_rx_frag() and reset frags array converting the buffer to a skb since the frag array will be in the same position for xdp_buff/xdp_frame and for the skb, we just need to update memory metadata. Introduce XDP_FLAGS_PF_MEMALLOC flag in xdp_buff_flags in order to mark the xdp_buff or xdp_frame as under memory-pressure if pages of the frags array are under memory pressure. Doing so we can avoid looping over all fragments in xdp_update_skb_shared_info routine. The driver is expected to set the flag constructing the xdp_buffer using xdp_buff_set_frag_pfmemalloc utility routine. Rely on xdp_update_skb_shared_info in __xdp_build_skb_from_frame routine converting the non-linear xdp_frame to a skb after performing a XDP_REDIRECT. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/bfd23fb8a8d7438724f7819c567cdf99ffd6226f.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * net: mvneta: simplify mvneta_swbm_add_rx_fragment managementLorenzo Bianconi2022-01-211-27/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Relying on xdp frags bit, remove skb_shared_info structure allocated on the stack in mvneta_rx_swbm routine and simplify mvneta_swbm_add_rx_fragment accessing skb_shared_info in the xdp_buff structure directly. There is no performance penalty in this approach since mvneta_swbm_add_rx_fragment is run just for xdp frags use-case. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/45f050c094ccffce49d6bc5112939ed35250ba90.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * net: mvneta: update frags bit before passing the xdp buffer to eBPF layerLorenzo Bianconi2022-01-211-5/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | Update frags bit (XDP_FLAGS_HAS_FRAGS) in xdp_buff to notify XDP/eBPF layer and XDP remote drivers if this is a "non-linear" XDP buffer. Access skb_shared_info only if XDP_FLAGS_HAS_FRAGS flag is set in order to avoid possible cache-misses. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/c00a73097f8a35860d50dae4a36e6cc9ef7e172f.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * xdp: introduce flags field in xdp_buff/xdp_frameLorenzo Bianconi2022-01-211-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce flags field in xdp_frame and xdp_buffer data structures to define additional buffer features. At the moment the only supported buffer feature is frags bit (XDP_FLAGS_HAS_FRAGS). frags bit is used to specify if this is a linear buffer (XDP_FLAGS_HAS_FRAGS not set) or a frags frame (XDP_FLAGS_HAS_FRAGS set). In the latter case the driver is expected to initialize the skb_shared_info structure at the end of the first buffer to link together subsequent buffers belonging to the same frame. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/e389f14f3a162c0a5bc6a2e1aa8dd01a90be117d.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * net: skbuff: add size metadata to skb_shared_info for xdpLorenzo Bianconi2022-01-211-0/+1
|/ | | | | | | | | | | | | | | Introduce xdp_frags_size field in skb_shared_info data structure to store xdp_buff/xdp_frame frame paged size (xdp_frags_size will be used in xdp frags support). In order to not increase skb_shared_info size we will use a hole due to skb_shared_info alignment. Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/8a849819a3e0a143d540f78a3a5add76e17e980d.1642758637.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* selftests: bpf: test BPF_PROG_QUERY for progs attached to sockmapDi Zhu2022-01-202-0/+90
| | | | | | | | | | | | Add test for querying progs attached to sockmap. we use an existing libbpf query interface to query prog cnt before and after progs attaching to sockmap and check whether the queried prog id is right. Signed-off-by: Di Zhu <zhudi2@huawei.com> Acked-by: Yonghong Song <yhs@fb.com> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/r/20220119014005.1209-2-zhudi2@huawei.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: support BPF_PROG_QUERY for progs attached to sockmapDi Zhu2022-01-203-7/+84
| | | | | | | | | | | | | | | Right now there is no way to query whether BPF programs are attached to a sockmap or not. we can use the standard interface in libbpf to query, such as: bpf_prog_query(mapFd, BPF_SK_SKB_STREAM_PARSER, 0, NULL, ...); the mapFd is the fd of sockmap. Signed-off-by: Di Zhu <zhudi2@huawei.com> Acked-by: Yonghong Song <yhs@fb.com> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/r/20220119014005.1209-1-zhudi2@huawei.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* Merge branch 'libbpf: streamline netlink-based XDP APIs'Alexei Starovoitov2022-01-2022-125/+205
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrii Nakryiko says: ==================== Revamp existing low-level XDP APIs provided by libbpf to follow more consistent naming (new APIs follow bpf_tc_xxx() approach where it makes sense) and be extensible without ABI breakages (OPTS-based). See patch #1 for details, remaining patches switch bpftool, selftests/bpf and samples/bpf to new APIs. ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * samples/bpf: adapt samples/bpf to bpf_xdp_xxx() APIsAndrii Nakryiko2022-01-2011-41/+40
| | | | | | | | | | | | | | | | Use new bpf_xdp_*() APIs across all XDP-related BPF samples. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220120061422.2710637-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * selftests/bpf: switch to new libbpf XDP APIsAndrii Nakryiko2022-01-207-50/+47
| | | | | | | | | | | | | | | | | | | | Switch to using new bpf_xdp_*() APIs across all selftests. Take advantage of a more straightforward and user-friendly semantics of old_prog_fd (0 means "don't care") in few places. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220120061422.2710637-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpftool: use new API for attaching XDP programAndrii Nakryiko2022-01-201-1/+1
| | | | | | | | | | | | | | | | Switch to new bpf_xdp_attach() API to avoid deprecation warnings. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220120061422.2710637-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * libbpf: streamline low-level XDP APIsAndrii Nakryiko2022-01-203-33/+117
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce 4 new netlink-based XDP APIs for attaching, detaching, and querying XDP programs: - bpf_xdp_attach; - bpf_xdp_detach; - bpf_xdp_query; - bpf_xdp_query_id. These APIs replace bpf_set_link_xdp_fd, bpf_set_link_xdp_fd_opts, bpf_get_link_xdp_id, and bpf_get_link_xdp_info APIs ([0]). The latter don't follow a consistent naming pattern and some of them use non-extensible approaches (e.g., struct xdp_link_info which can't be modified without breaking libbpf ABI). The approach I took with these low-level XDP APIs is similar to what we did with low-level TC APIs. There is a nice duality of bpf_tc_attach vs bpf_xdp_attach, and so on. I left bpf_xdp_attach() to support detaching when -1 is specified for prog_fd for generality and convenience, but bpf_xdp_detach() is preferred due to clearer naming and associated semantics. Both bpf_xdp_attach() and bpf_xdp_detach() accept the same opts struct allowing to specify expected old_prog_fd. While doing the refactoring, I noticed that old APIs require users to specify opts with old_fd == -1 to declare "don't care about already attached XDP prog fd" condition. Otherwise, FD 0 is assumed, which is essentially never an intended behavior. So I made this behavior consistent with other kernel and libbpf APIs, in which zero FD means "no FD". This seems to be more in line with the latest thinking in BPF land and should cause less user confusion, hopefully. For querying, I left two APIs, both more generic bpf_xdp_query() allowing to query multiple IDs and attach mode, but also a specialization of it, bpf_xdp_query_id(), which returns only requested prog_id. Uses of prog_id returning bpf_get_link_xdp_id() were so prevalent across selftests and samples, that it seemed a very common use case and using bpf_xdp_query() for doing it felt very cumbersome with a highly branches if/else chain based on flags and attach mode. Old APIs are scheduled for deprecation in libbpf 0.8 release. [0] Closes: https://github.com/libbpf/libbpf/issues/309 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20220120061422.2710637-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* Merge branch 'libbpf: deprecate legacy BPF map definitions'Alexei Starovoitov2022-01-2015-64/+90
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrii Nakryiko says: ==================== Officially deprecate legacy BPF map definitions in libbpf. They've been slated for deprecation for a while in favor of more powerful BTF-defined map definitions and this patch set adds warnings and a way to enforce this in libbpf through LIBBPF_STRICT_MAP_DEFINITIONS strict mode flag. Selftests are fixed up and updated, BPF documentation is updated, bpftool's strict mode usage is adjusted to avoid breaking users unnecessarily. v1->v2: - replace missed bpf_map_def case in Documentation/bpf/btf.rst (Alexei). ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * docs/bpf: update BPF map definition exampleAndrii Nakryiko2022-01-201-18/+14
| | | | | | | | | | | | | | | | Use BTF-defined map definition in the documentation example. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220120060529.1890907-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * libbpf: deprecate legacy BPF map definitionsAndrii Nakryiko2022-01-205-2/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enact deprecation of legacy BPF map definition in SEC("maps") ([0]). For the definitions themselves introduce LIBBPF_STRICT_MAP_DEFINITIONS flag for libbpf strict mode. If it is set, error out on any struct bpf_map_def-based map definition. If not set, libbpf will print out a warning for each legacy BPF map to raise awareness that it goes away. For any use of BPF_ANNOTATE_KV_PAIR() macro providing a legacy way to associate BTF key/value type information with legacy BPF map definition, warn through libbpf's pr_warn() error message (but don't fail BPF object open). BPF-side struct bpf_map_def is marked as deprecated. User-space struct bpf_map_def has to be used internally in libbpf, so it is left untouched. It should be enough for bpf_map__def() to be marked deprecated to raise awareness that it goes away. bpftool is an interesting case that utilizes libbpf to open BPF ELF object to generate skeleton. As such, even though bpftool itself uses full on strict libbpf mode (LIBBPF_STRICT_ALL), it has to relax it a bit for BPF map definition handling to minimize unnecessary disruptions. So opt-out of LIBBPF_STRICT_MAP_DEFINITIONS for bpftool. User's code that will later use generated skeleton will make its own decision whether to enforce LIBBPF_STRICT_MAP_DEFINITIONS or not. There are few tests in selftests/bpf that are consciously using legacy BPF map definitions to test libbpf functionality. For those, temporary opt out of LIBBPF_STRICT_MAP_DEFINITIONS mode for the duration of those tests. [0] Closes: https://github.com/libbpf/libbpf/issues/272 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220120060529.1890907-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * selftests/bpf: convert remaining legacy map definitionsAndrii Nakryiko2022-01-208-42/+48
| | | | | | | | | | | | | | | | | | | | | | | | Converted few remaining legacy BPF map definition to BTF-defined ones. For the remaining two bpf_map_def-based legacy definitions that we want to keep for testing purposes until libbpf 1.0 release, guard them in pragma to suppres deprecation warnings which will be added in libbpf in the next commit. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220120060529.1890907-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * selftests/bpf: fail build on compilation warningAndrii Nakryiko2022-01-201-2/+2
|/ | | | | | | | | | | It's very easy to miss compilation warnings without -Werror, which is not set for selftests. libbpf and bpftool are already strict about this, so make selftests/bpf also treat compilation warnings as errors to catch such regressions early. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220120060529.1890907-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* selftests/bpf: Do not fail build if CONFIG_NF_CONNTRACK=m/nKumar Kartikeya Dwivedi2022-01-201-4/+13
| | | | | | | | | | | | | Some users have complained that selftests fail to build when CONFIG_NF_CONNTRACK=m. It would be useful to allow building as long as it is set to module or built-in, even though in case of building as module, user would need to load it before running the selftest. Note that this also allows building selftest when CONFIG_NF_CONNTRACK is disabled. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220120164932.2798544-1-memxor@gmail.com
* selftests: bpf: Fix bind on used portFelix Maurer2022-01-201-3/+17
| | | | | | | | | | | | | | | | | The bind_perm BPF selftest failed when port 111/tcp was already in use during the test. To fix this, the test now runs in its own network name space. To use unshare, it is necessary to reorder the includes. The style of the includes is adapted to be consistent with the other prog_tests. v2: Replace deprecated CHECK macro with ASSERT_OK Fixes: 8259fdeb30326 ("selftests/bpf: Verify that rebinding to port < 1024 from BPF works") Signed-off-by: Felix Maurer <fmaurer@redhat.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/551ee65533bb987a43f93d88eaf2368b416ccd32.1642518457.git.fmaurer@redhat.com
* Merge branch 'rely on ASSERT marcos in xdp_bpf2bpf.c/xdp_adjust_tail.c'Andrii Nakryiko2022-01-202-80/+48
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lorenzo Bianconi says: ==================== Rely on ASSERT* macros and get rid of deprecated CHECK ones in xdp_bpf2bpf and xdp_adjust_tail bpf selftests. This is a preliminary series for XDP multi-frags support. Changes since v1: - run each ASSERT test separately - drop unnecessary return statements - drop unnecessary if condition in test_xdp_bpf2bpf() ==================== Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
| * bpf: selftests: Get rid of CHECK macro in xdp_bpf2bpf.cLorenzo Bianconi2022-01-201-40/+20
| | | | | | | | | | | | | | | | | | Rely on ASSERT* macros and get rid of deprecated CHECK ones in xdp_bpf2bpf bpf selftest. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/df7e5098465016e27d91f2c69a376a35d63a7621.1642679130.git.lorenzo@kernel.org
| * bpf: selftests: Get rid of CHECK macro in xdp_adjust_tail.cLorenzo Bianconi2022-01-201-40/+28
|/ | | | | | | | | Rely on ASSERT* macros and get rid of deprecated CHECK ones in xdp_adjust_tail bpf selftest. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/c0ab002ffa647a20ec9e584214bf0d4373142b54.1642679130.git.lorenzo@kernel.org
* Merge branch 'bpf: allow cgroup progs to export custom retval to userspace'Alexei Starovoitov2022-01-1911-89/+751
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | YiFei Zhu says: ==================== Right now, most cgroup hooks are best used for permission checks. They can only reject a syscall with -EPERM, so a cause of a rejection, if the rejected by eBPF cgroup hooks, is ambiguous to userspace. Additionally, if the syscalls are implemented in eBPF, all permission checks and the implementation has to happen within the same filter, as programs executed later in the series of progs are unaware of the return values return by the previous progs. This patch series adds two helpers, bpf_get_retval and bpf_set_retval, that allows hooks to get/set the return value of syscall to userspace. This also allows later progs to retrieve retval set by previous progs. For legacy programs that rejects a syscall without setting the retval, for backwards compatibility, if a prog rejects without itself or a prior prog setting retval to an -err, the retval is set by the kernel to -EPERM. For getsockopt hooks that has ctx->retval, this variable mirrors that that accessed by the helpers. Additionally, the following user-visible behavior for getsockopt hooks has changed: - If a prior filter rejected the syscall, it will be visible in ctx->retval. - Attempting to change the retval arbitrarily is now allowed and will not cause an -EFAULT. - If kernel rejects a getsockopt syscall before running the hooks, the error will be visible in ctx->retval. Returning 0 from the prog will not overwrite the error to -EPERM unless there is an explicit call of bpf_set_retval(-EPERM) Tests have been added in this series to test the behavior of the helper with cgroup setsockopt getsockopt hooks. Patch 1 changes the API of macros to prepare for the next patch and should be a no-op. Patch 2 moves ctx->retval to a struct pointed to by current task_struct. Patch 3 implements the helpers. Patch 4 tests the behaviors of the helpers. Patch 5 updates a test after the test broke due to the visible changes. v1 -> v2: - errno -> retval - split one helper to get & set helpers - allow retval to be set arbitrarily in the general case - made the helper retval and context retval mirror each other ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * selftests/bpf: Update sockopt_sk test to the use bpf_set_retvalYiFei Zhu2022-01-192-18/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tests would break without this patch, because at one point it calls getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen) This getsockopt receives the kernel-set -EINVAL. Prior to this patch series, the eBPF getsockopt hook's -EPERM would override kernel's -EINVAL, however, after this patch series, return 0's automatic -EPERM will not; the eBPF prog has to explicitly bpf_set_retval(-EPERM) if that is wanted. I also removed the explicit mentions of EPERM in the comments in the prog. Signed-off-by: YiFei Zhu <zhuyifei@google.com> Reviewed-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/4f20b77cb46812dbc2bdcd7e3fa87c7573bde55e.1639619851.git.zhuyifei@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * selftests/bpf: Test bpf_{get,set}_retval behavior with cgroup/sockoptYiFei Zhu2022-01-193-0/+578
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The tests checks how different ways of interacting with the helpers (getting retval, setting EUNATCH, EISCONN, and legacy reject returning 0 without setting retval), produce different results in both the setsockopt syscall and the retval returned by the helper. A few more tests verify the interaction between the retval of the helper and the retval in getsockopt context. Signed-off-by: YiFei Zhu <zhuyifei@google.com> Reviewed-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/43ec60d679ae3f4f6fd2460559c28b63cb93cd12.1639619851.git.zhuyifei@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: Add cgroup helpers bpf_{get,set}_retval to get/set syscall return valueYiFei Zhu2022-01-194-5/+79
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The helpers continue to use int for retval because all the hooks are int-returning rather than long-returning. The return value of bpf_set_retval is int for future-proofing, in case in the future there may be errors trying to set the retval. After the previous patch, if a program rejects a syscall by returning 0, an -EPERM will be generated no matter if the retval is already set to -err. This patch change it being forced only if retval is not -err. This is because we want to support, for example, invoking bpf_set_retval(-EINVAL) and return 0, and have the syscall return value be -EINVAL not -EPERM. For BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY, the prior behavior is that, if the return value is NET_XMIT_DROP, the packet is silently dropped. We preserve this behavior for backward compatibility reasons, so even if an errno is set, the errno does not return to caller. However, setting a non-err to retval cannot propagate so this is not allowed and we return a -EFAULT in that case. Signed-off-by: YiFei Zhu <zhuyifei@google.com> Reviewed-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/b4013fd5d16bed0b01977c1fafdeae12e1de61fb.1639619851.git.zhuyifei@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: Move getsockopt retval to struct bpf_cg_run_ctxYiFei Zhu2022-01-193-44/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The retval value is moved to struct bpf_cg_run_ctx for ease of access in different prog types with different context structs layouts. The helper implementation (to be added in a later patch in the series) can simply perform a container_of from current->bpf_ctx to retrieve bpf_cg_run_ctx. Unfortunately, there is no easy way to access the current task_struct via the verifier BPF bytecode rewrite, aside from possibly calling a helper, so a pointer to current task is added to struct bpf_sockopt_kern so that the rewritten BPF bytecode can access struct bpf_cg_run_ctx with an indirection. For backward compatibility, if a getsockopt program rejects a syscall by returning 0, an -EPERM will be generated, by having the BPF_PROG_RUN_ARRAY_CG family macros automatically set the retval to -EPERM. Unlike prior to this patch, this -EPERM will be visible to ctx->retval for any other hooks down the line in the prog array. Additionally, the restriction that getsockopt filters can only set the retval to 0 is removed, considering that certain getsockopt implementations may return optlen. Filters are now able to set the value arbitrarily. Signed-off-by: YiFei Zhu <zhuyifei@google.com> Reviewed-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/73b0325f5c29912ccea7ea57ec1ed4d388fc1d37.1639619851.git.zhuyifei@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf: Make BPF_PROG_RUN_ARRAY return -err instead of allow booleanYiFei Zhu2022-01-193-34/+25
|/ | | | | | | | | | | | | | | | | | Right now BPF_PROG_RUN_ARRAY and related macros return 1 or 0 for whether the prog array allows or rejects whatever is being hooked. The caller of these macros then return -EPERM or continue processing based on thw macro's return value. Unforunately this is inflexible, since -EPERM is the only err that can be returned. This patch should be a no-op; it prepares for the next patch. The returning of the -EPERM is moved to inside the macros, so the outer functions are directly returning what the macros returned if they are non-zero. Signed-off-by: YiFei Zhu <zhuyifei@google.com> Reviewed-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/788abcdca55886d1f43274c918eaa9f792a9f33b.1639619851.git.zhuyifei@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* libbpf: Improve btf__add_btf() with an additional hashmap for strings.Kui-Feng Lee2022-01-191-1/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a hashmap to map the string offsets from a source btf to the string offsets from a target btf to reduce overheads. btf__add_btf() calls btf__add_str() to add strings from a source to a target btf. It causes many string comparisons, and it is a major hotspot when adding a big btf. btf__add_str() uses strcmp() to check if a hash entry is the right one. The extra hashmap here compares offsets of strings, that are much cheaper. It remembers the results of btf__add_str() for later uses to reduce the cost. We are parallelizing BTF encoding for pahole by creating separated btf instances for worker threads. These per-thread btf instances will be added to the btf instance of the main thread by calling btf__add_str() to deduplicate and write out. With this patch and -j4, the running time of pahole drops to about 6.0s from 6.6s. The following lines are the summary of 'perf stat' w/o the change. 6.668126396 seconds time elapsed 13.451054000 seconds user 0.715520000 seconds sys The following lines are the summary w/ the change. 5.986973919 seconds time elapsed 12.939903000 seconds user 0.724152000 seconds sys V4 fixes a bug of error checking against the pointer returned by hashmap__new(). [v3] https://lore.kernel.org/bpf/20220118232053.2113139-1-kuifeng@fb.com/ [v2] https://lore.kernel.org/bpf/20220114193713.461349-1-kuifeng@fb.com/ Signed-off-by: Kui-Feng Lee <kuifeng@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220119180214.255634-1-kuifeng@fb.com
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