1. 20 4月, 2018 10 次提交
    • M
      bpf: btf: Add BTF tests · c0fa1b6c
      Martin KaFai Lau 提交于
      This patch tests the BTF loading, map_create with BTF
      and the changes in libbpf.
      
      -r: Raw tests that test raw crafted BTF data
      -f: Test LLVM compiled bpf prog with BTF data
      -g: Test BPF_OBJ_GET_INFO_BY_FD for btf_fd
      -p: Test pretty print
      
      The tools/testing/selftests/bpf/Makefile will probe
      for BTF support in llc and pahole before generating
      debug info (-g) and convert them to BTF.  You can supply
      the BTF supported binary through the following make variables:
      LLC, BTF_PAHOLE and LLVM_OBJCOPY.
      
      LLC: The lastest llc with -mattr=dwarfris support for the bpf target.
           It is only in the master of the llvm repo for now.
      BTF_PAHOLE: The modified pahole with BTF support:
      	    https://github.com/iamkafai/pahole/tree/btf
      	    To add a BTF section: "pahole -J bpf_prog.o"
      LLVM_OBJCOPY: Any llvm-objcopy should do
      Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NAlexei Starovoitov <ast@fb.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      c0fa1b6c
    • M
      bpf: btf: Add BTF support to libbpf · 8a138aed
      Martin KaFai Lau 提交于
      If the ".BTF" elf section exists, libbpf will try to create
      a btf_fd (through BPF_BTF_LOAD).  If that fails, it will still
      continue loading the bpf prog/map without the BTF.
      
      If the bpf_object has a BTF loaded, it will create a map with the btf_fd.
      libbpf will try to figure out the btf_key_id and btf_value_id of a map by
      finding the BTF type with name "<map_name>_key" and "<map_name>_value".
      If they cannot be found, it will continue without using the BTF.
      Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NAlexei Starovoitov <ast@fb.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      8a138aed
    • M
      bpf: btf: Sync bpf.h and btf.h to tools/ · 3bd86a84
      Martin KaFai Lau 提交于
      This patch sync up the bpf.h and btf.h to tools/
      Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NAlexei Starovoitov <ast@fb.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      3bd86a84
    • M
      bpf: btf: Add pretty print support to the basic arraymap · a26ca7c9
      Martin KaFai Lau 提交于
      This patch adds pretty print support to the basic arraymap.
      Support for other bpf maps can be added later.
      
      This patch adds new attrs to the BPF_MAP_CREATE command to allow
      specifying the btf_fd, btf_key_id and btf_value_id.  The
      BPF_MAP_CREATE can then associate the btf to the map if
      the creating map supports BTF.
      
      A BTF supported map needs to implement two new map ops,
      map_seq_show_elem() and map_check_btf().  This patch has
      implemented these new map ops for the basic arraymap.
      
      It also adds file_operations, bpffs_map_fops, to the pinned
      map such that the pinned map can be opened and read.
      After that, the user has an intuitive way to do
      "cat bpffs/pathto/a-pinned-map" instead of getting
      an error.
      
      bpffs_map_fops should not be extended further to support
      other operations.  Other operations (e.g. write/key-lookup...)
      should be realized by the userspace tools (e.g. bpftool) through
      the BPF_OBJ_GET_INFO_BY_FD, map's lookup/update interface...etc.
      Follow up patches will allow the userspace to obtain
      the BTF from a map-fd.
      
      Here is a sample output when reading a pinned arraymap
      with the following map's value:
      
      struct map_value {
      	int count_a;
      	int count_b;
      };
      
      cat /sys/fs/bpf/pinned_array_map:
      
      0: {1,2}
      1: {3,4}
      2: {5,6}
      ...
      Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NAlexei Starovoitov <ast@fb.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      a26ca7c9
    • M
      bpf: btf: Add BPF_OBJ_GET_INFO_BY_FD support to BTF fd · 60197cfb
      Martin KaFai Lau 提交于
      This patch adds BPF_OBJ_GET_INFO_BY_FD support to BTF fd.
      The original BTF data, which was used to create the BTF fd during
      the earlier BPF_BTF_LOAD call, will be returned.
      
      The userspace is expected to allocate buffer
      to info.info and the buffer size is set to info.info_len before
      calling BPF_OBJ_GET_INFO_BY_FD.
      
      The original BTF data is copied to the userspace buffer (info.info).
      Only upto the user's specified info.info_len will be copied.
      
      The original BTF data size is set to info.info_len.  The userspace
      needs to check if it is bigger than its allocated buffer size.
      If it is, the userspace should realloc with the kernel-returned
      info.info_len and call the BPF_OBJ_GET_INFO_BY_FD again.
      Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NAlexei Starovoitov <ast@fb.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      60197cfb
    • M
      bpf: btf: Add BPF_BTF_LOAD command · f56a653c
      Martin KaFai Lau 提交于
      This patch adds a BPF_BTF_LOAD command which
      1) loads and verifies the BTF (implemented in earlier patches)
      2) returns a BTF fd to userspace.  In the next patch, the
         BTF fd can be specified during BPF_MAP_CREATE.
      
      It currently limits to CAP_SYS_ADMIN.
      Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NAlexei Starovoitov <ast@fb.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      f56a653c
    • M
      bpf: btf: Add pretty print capability for data with BTF type info · b00b8dae
      Martin KaFai Lau 提交于
      This patch adds pretty print capability for data with BTF type info.
      The current usage is to allow pretty print for a BPF map.
      
      The next few patches will allow a read() on a pinned map with BTF
      type info for its key and value.
      
      This patch uses the seq_printf() infra.
      Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NAlexei Starovoitov <ast@fb.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      b00b8dae
    • M
      bpf: btf: Check members of struct/union · 179cde8c
      Martin KaFai Lau 提交于
      This patch checks a few things of struct's members:
      
      1) It has a valid size (e.g. a "const void" is invalid)
      2) A member's size (+ its member's offset) does not exceed
         the containing struct's size.
      3) The member's offset satisfies the alignment requirement
      
      The above can only be done after the needs_resolve member's type
      is resolved.  Hence, the above is done together in
      btf_struct_resolve().
      
      Each possible member's type (e.g. int, enum, modifier...) implements
      the check_member() ops which will be called from btf_struct_resolve().
      Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NAlexei Starovoitov <ast@fb.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      179cde8c
    • M
      bpf: btf: Validate type reference · eb3f595d
      Martin KaFai Lau 提交于
      After collecting all btf_type in the first pass in an earlier patch,
      the second pass (in this patch) can validate the reference types
      (e.g. the referring type does exist and it does not refer to itself).
      
      While checking the reference type, it also gathers other information (e.g.
      the size of an array).  This info will be useful in checking the
      struct's members in a later patch.  They will also be useful in doing
      pretty print later.
      Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NAlexei Starovoitov <ast@fb.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      eb3f595d
    • M
      bpf: btf: Introduce BPF Type Format (BTF) · 69b693f0
      Martin KaFai Lau 提交于
      This patch introduces BPF type Format (BTF).
      
      BTF (BPF Type Format) is the meta data format which describes
      the data types of BPF program/map.  Hence, it basically focus
      on the C programming language which the modern BPF is primary
      using.  The first use case is to provide a generic pretty print
      capability for a BPF map.
      
      BTF has its root from CTF (Compact C-Type format).  To simplify
      the handling of BTF data, BTF removes the differences between
      small and big type/struct-member.  Hence, BTF consistently uses u32
      instead of supporting both "one u16" and "two u32 (+padding)" in
      describing type and struct-member.
      
      It also raises the number of types (and functions) limit
      from 0x7fff to 0x7fffffff.
      
      Due to the above changes,  the format is not compatible to CTF.
      Hence, BTF starts with a new BTF_MAGIC and version number.
      
      This patch does the first verification pass to the BTF.  The first
      pass checks:
      1. meta-data size (e.g. It does not go beyond the total btf's size)
      2. name_offset is valid
      3. Each BTF_KIND (e.g. int, enum, struct....) does its
         own check of its meta-data.
      
      Some other checks, like checking a struct's member is referring
      to a valid type, can only be done in the second pass.  The second
      verification pass will be implemented in the next patch.
      Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NAlexei Starovoitov <ast@fb.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      69b693f0
  2. 19 4月, 2018 13 次提交
  3. 18 4月, 2018 15 次提交
  4. 17 4月, 2018 2 次提交
    • D
      Merge branch 'XDP-redirect-memory-return-API' · 684009d4
      David S. Miller 提交于
      Jesper Dangaard Brouer says:
      
      ====================
      XDP redirect memory return API
      
      Submitted against net-next, as it contains NIC driver changes.
      
      This patchset works towards supporting different XDP RX-ring memory
      allocators.  As this will be needed by the AF_XDP zero-copy mode.
      
      The patchset uses mlx5 as the sample driver, which gets implemented
      XDP_REDIRECT RX-mode, but not ndo_xdp_xmit (as this API is subject to
      change thought the patchset).
      
      A new struct xdp_frame is introduced (modeled after cpumap xdp_pkt).
      And both ndo_xdp_xmit and the new xdp_return_frame end-up using this.
      
      Support for a driver supplied allocator is implemented, and a
      refurbished version of page_pool is the first return allocator type
      introduced.  This will be a integration point for AF_XDP zero-copy.
      
      The mlx5 driver evolve into using the page_pool, and see a performance
      increase (with ndo_xdp_xmit out ixgbe driver) from 6Mpps to 12Mpps.
      
      The patchset stop at 16 patches (one over limit), but more API changes
      are planned.  Specifically extending ndo_xdp_xmit and xdp_return_frame
      APIs to support bulking.  As this will address some known limits.
      
      V2: Updated according to Tariq's feedback
      V3: Updated based on feedback from Jason Wang and Alex Duyck
      V4: Updated based on feedback from Tariq and Jason
      V5: Fix SPDX license, add Tariq's reviews, improve patch desc for perf test
      V6: Updated based on feedback from Eric Dumazet and Alex Duyck
      V7: Adapt to i40e that got XDP_REDIRECT support in-between
      V8:
       Updated based on feedback kbuild test robot, and adjust for mlx5 changes
       page_pool only compiled into kernel when drivers Kconfig 'select' feature
      V9:
       Remove some inline statements, let compiler decide what to inline
       Fix return value in virtio_net driver
       Adjust for mlx5 changes in-between submissions
      V10:
       Minor adjust for mlx5 requested by Tariq
       Resubmit against net-next
      V11: avoid leaking info stored in frame data on page reuse
      ====================
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      684009d4
    • J
      xdp: avoid leaking info stored in frame data on page reuse · 6dfb970d
      Jesper Dangaard Brouer 提交于
      The bpf infrastructure and verifier goes to great length to avoid
      bpf progs leaking kernel (pointer) info.
      
      For queueing an xdp_buff via XDP_REDIRECT, xdp_frame info stores
      kernel info (incl pointers) in top part of frame data (xdp->data_hard_start).
      Checks are in place to assure enough headroom is available for this.
      
      This info is not cleared, and if the frame is reused, then a
      malicious user could use bpf_xdp_adjust_head helper to move
      xdp->data into this area.  Thus, making this area readable.
      
      This is not super critical as XDP progs requires root or
      CAP_SYS_ADMIN, which are privileged enough for such info.  An
      effort (is underway) towards moving networking bpf hooks to the
      lesser privileged mode CAP_NET_ADMIN, where leaking such info
      should be avoided.  Thus, this patch to clear the info when
      needed.
      Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6dfb970d