1. 24 May, 2018 2 commits
    • Sandipan Das's avatar
      bpf: support 64-bit offsets for bpf function calls · 2162fed4
      Sandipan Das authored
      The imm field of a bpf instruction is a signed 32-bit integer.
      For JITed bpf-to-bpf function calls, it holds the offset of the
      start address of the callee's JITed image from __bpf_call_base.
      
      For some architectures, such as powerpc64, this offset may be
      as large as 64 bits and cannot be accomodated in the imm field
      without truncation.
      
      We resolve this by:
      
      [1] Additionally using the auxiliary data of each function to
          keep a list of start addresses of the JITed images for all
          functions determined by the verifier.
      
      [2] Retaining the subprog id inside the off field of the call
          instructions and using it to index into the list mentioned
          above and lookup the callee's address.
      
      To make sure that the existing JIT compilers continue to work
      without requiring changes, we keep the imm field as it is.
      Signed-off-by: default avatarSandipan Das <sandipan@linux.vnet.ibm.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      2162fed4
    • Martin KaFai Lau's avatar
      bpf: btf: Avoid variable length array · a2889a4c
      Martin KaFai Lau authored
      Sparse warning:
      kernel/bpf/btf.c:1985:34: warning: Variable length array is used.
      
      This patch directly uses ARRAY_SIZE().
      
      Fixes: f80442a4 ("bpf: btf: Change how section is supported in btf_header")
      Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      a2889a4c
  2. 23 May, 2018 10 commits
    • Sirio Balmelli's avatar
      tools/lib/libbpf.c: fix string format to allow build on arm32 · a1c81810
      Sirio Balmelli authored
      On arm32, 'cd tools/testing/selftests/bpf && make' fails with:
      
      libbpf.c:80:10: error: format ‘%ld’ expects argument of type ‘long int’, but argument 4 has type ‘int64_t {aka long long int}’ [-Werror=format=]
         (func)("libbpf: " fmt, ##__VA_ARGS__); \
                ^
      libbpf.c:83:30: note: in expansion of macro ‘__pr’
       #define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__)
                                    ^~~~
      libbpf.c:1072:3: note: in expansion of macro ‘pr_warning’
         pr_warning("map:%s value_type:%s has BTF type_size:%ld != value_size:%u\n",
      
      To fix, typecast 'key_size' and amend format string.
      Signed-off-by: default avatarSirio Balmelli <sirio@b-ad.ch>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      a1c81810
    • Sirio Balmelli's avatar
      selftests/bpf: Makefile fix "missing" headers on build with -idirafter · 167381f3
      Sirio Balmelli authored
      Selftests fail to build on several distros/architectures because of
      	missing headers files.
      
      On a Ubuntu/x86_64 some missing headers are:
      	asm/byteorder.h, asm/socket.h, asm/sockios.h
      
      On a Debian/arm32 build already fails at sys/cdefs.h
      
      In both cases, these already exist in /usr/include/<arch-specific-dir>,
      but Clang does not include these when using '-target bpf' flag,
      since it is no longer compiling against the host architecture.
      
      The solution is to:
      
      - run Clang without '-target bpf' and extract the include chain for the
      current system
      
      - add these to the bpf build with '-idirafter'
      
      The choice of -idirafter is to catch this error without injecting
      unexpected include behavior: if an arch-specific tree is built
      for bpf in the future, this will be correctly found by Clang.
      Signed-off-by: default avatarSirio Balmelli <sirio@b-ad.ch>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      167381f3
    • Daniel Borkmann's avatar
      Merge branch 'btf-uapi-cleanups' · ff4fb475
      Daniel Borkmann authored
      Martin KaFai Lau says:
      
      ====================
      This patch set makes some changes to cleanup the unused
      bits in BTF uapi.  It also makes the btf_header extensible.
      
      Please see individual patches for details.
      
      v2:
      - Remove NR_SECS from patch 2
      - Remove "unsigned" check on array->index_type from patch 3
      - Remove BTF_INT_VARARGS and further limit BTF_INT_ENCODING
        from 8 bits to 4 bits in patch 4
      - Adjustments in test_btf.c to reflect changes in v2
      ====================
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      ff4fb475
    • Martin KaFai Lau's avatar
      bpf: btf: Add tests for the btf uapi changes · 61746dbe
      Martin KaFai Lau authored
      This patch does the followings:
      1. Modify libbpf and test_btf to reflect the uapi changes in btf
      2. Add test for the btf_header changes
      3. Add tests for array->index_type
      4. Add err_str check to the tests
      5. Fix a 4 bytes hole in "struct test #1" by swapping "m" and "n"
      Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      61746dbe
    • Martin KaFai Lau's avatar
      bpf: btf: Sync bpf.h and btf.h to tools · f03b15d3
      Martin KaFai Lau authored
      This patch sync the uapi bpf.h and btf.h to tools.
      Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
      Acked-by: default avatarYonghong Song <yhs@fb.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      f03b15d3
    • Martin KaFai Lau's avatar
      bpf: btf: Rename btf_key_id and btf_value_id in bpf_map_info · 9b2cf328
      Martin KaFai Lau authored
      In "struct bpf_map_info", the name "btf_id", "btf_key_id" and "btf_value_id"
      could cause confusion because the "id" of "btf_id" means the BPF obj id
      given to the BTF object while
      "btf_key_id" and "btf_value_id" means the BTF type id within
      that BTF object.
      
      To make it clear, btf_key_id and btf_value_id are
      renamed to btf_key_type_id and btf_value_type_id.
      Suggested-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
      Acked-by: default avatarYonghong Song <yhs@fb.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      9b2cf328
    • Martin KaFai Lau's avatar
      bpf: btf: Remove unused bits from uapi/linux/btf.h · aea2f7b8
      Martin KaFai Lau authored
      This patch does the followings:
      1. Limit BTF_MAX_TYPES and BTF_MAX_NAME_OFFSET to 64k.  We can
         raise it later.
      
      2. Remove the BTF_TYPE_PARENT and BTF_STR_TBL_ELF_ID.  They are
         currently encoded at the highest bit of a u32.
         It is because the current use case does not require supporting
         parent type (i.e type_id referring to a type in another BTF file).
         It also does not support referring to a string in ELF.
      
         The BTF_TYPE_PARENT and BTF_STR_TBL_ELF_ID checks are replaced
         by BTF_TYPE_ID_CHECK and BTF_STR_OFFSET_CHECK which are
         defined in btf.c instead of uapi/linux/btf.h.
      
      3. Limit the BTF_INFO_KIND from 5 bits to 4 bits which is enough.
         There is unused bits headroom if we ever needed it later.
      
      4. The root bit in BTF_INFO is also removed because it is not
         used in the current use case.
      
      5. Remove BTF_INT_VARARGS since func type is not supported now.
         The BTF_INT_ENCODING is limited to 4 bits instead of 8 bits.
      
      The above can be added back later because the verifier
      ensures the unused bits are zeros.
      Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
      Acked-by: default avatarYonghong Song <yhs@fb.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      aea2f7b8
    • Martin KaFai Lau's avatar
      bpf: btf: Check array->index_type · 4ef5f574
      Martin KaFai Lau authored
      Instead of ingoring the array->index_type field.  Enforce that
      it must be a BTF_KIND_INT in size 1/2/4/8 bytes.
      Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      4ef5f574
    • Martin KaFai Lau's avatar
      bpf: btf: Change how section is supported in btf_header · f80442a4
      Martin KaFai Lau authored
      There are currently unused section descriptions in the btf_header.  Those
      sections are here to support future BTF use cases.  For example, the
      func section (func_off) is to support function signature (e.g. the BPF
      prog function signature).
      
      Instead of spelling out all potential sections up-front in the btf_header.
      This patch makes changes to btf_header such that extending it (e.g. adding
      a section) is possible later.  The unused ones can be removed for now and
      they can be added back later.
      
      This patch:
      1. adds a hdr_len to the btf_header.  It will allow adding
      sections (and other info like parent_label and parent_name)
      later.  The check is similar to the existing bpf_attr.
      If a user passes in a longer hdr_len, the kernel
      ensures the extra tailing bytes are 0.
      
      2. allows the section order in the BTF object to be
      different from its sec_off order in btf_header.
      
      3. each sec_off is followed by a sec_len.  It must not have gap or
      overlapping among sections.
      
      The string section is ensured to be at the end due to the 4 bytes
      alignment requirement of the type section.
      
      The above changes will allow enough flexibility to
      add new sections (and other info) to the btf_header later.
      
      This patch also removes an unnecessary !err check
      at the end of btf_parse().
      Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      f80442a4
    • Martin KaFai Lau's avatar
      bpf: Expose check_uarg_tail_zero() · dcab51f1
      Martin KaFai Lau authored
      This patch exposes check_uarg_tail_zero() which will
      be reused by a later BTF patch.  Its name is changed to
      bpf_check_uarg_tail_zero().
      Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
      Acked-by: default avatarYonghong Song <yhs@fb.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      dcab51f1
  3. 22 May, 2018 13 commits
  4. 18 May, 2018 12 commits
  5. 17 May, 2018 3 commits