Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2019-01-29

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Teach verifier dead code removal, this also allows for optimizing /
   removing conditional branches around dead code and to shrink the
   resulting image. Code store constrained architectures like nfp would
   have hard time doing this at JIT level, from Jakub.

2) Add JMP32 instructions to BPF ISA in order to allow for optimizing
   code generation for 32-bit sub-registers. Evaluation shows that this
   can result in code reduction of ~5-20% compared to 64 bit-only code
   generation. Also add implementation for most JITs, from Jiong.

3) Add support for __int128 types in BTF which is also needed for
   vmlinux's BTF conversion to work, from Yonghong.

4) Add a new command to bpftool in order to dump a list of BPF-related
   parameters from the system or for a specific network device e.g. in
   terms of available prog/map types or helper functions, from Quentin.

5) Add AF_XDP sock_diag interface for querying sockets from user
   space which provides information about the RX/TX/fill/completion
   rings, umem, memory usage etc, from Björn.

6) Add skb context access for skb_shared_info->gso_segs field, from Eric.

7) Add support for testing flow dissector BPF programs by extending
   existing BPF_PROG_TEST_RUN infrastructure, from Stanislav.

8) Split BPF kselftest's test_verifier into various subgroups of tests
   in order better deal with merge conflicts in this area, from Jakub.

9) Add support for queue/stack manipulations in bpftool, from Stanislav.

10) Document BTF, from Yonghong.

11) Dump supported ELF section names in libbpf on program load
    failure, from Taeung.

12) Silence a false positive compiler warning in verifier's BTF
    handling, from Peter.

13) Fix help string in bpftool's feature probing, from Prashant.

14) Remove duplicate includes in BPF kselftests, from Yue.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 7 deletions

diff --git a/Documentation/networking/filter.txt b/Documentation/networking/filter.txt
index 2196b824e96c..01603bc2eff1 100644
--- a/Documentation/networking/filter.txt
+++ b/Documentation/networking/filter.txt
@@ -865,7 +865,7 @@ Three LSB bits store instruction class which is one of:
   BPF_STX   0x03          BPF_STX   0x03
   BPF_ALU   0x04          BPF_ALU   0x04
   BPF_JMP   0x05          BPF_JMP   0x05
-  BPF_RET   0x06          [ class 6 unused, for future if needed ]
+  BPF_RET   0x06          BPF_JMP32 0x06
   BPF_MISC  0x07          BPF_ALU64 0x07
 
 When BPF_CLASS(code) == BPF_ALU or BPF_JMP, 4th bit encodes source operand ...
@@ -902,9 +902,9 @@ If BPF_CLASS(code) == BPF_ALU or BPF_ALU64 [ in eBPF ], BPF_OP(code) is one of:
   BPF_ARSH  0xc0  /* eBPF only: sign extending shift right */
   BPF_END   0xd0  /* eBPF only: endianness conversion */
 
-If BPF_CLASS(code) == BPF_JMP, BPF_OP(code) is one of:
+If BPF_CLASS(code) == BPF_JMP or BPF_JMP32 [ in eBPF ], BPF_OP(code) is one of:
 
-  BPF_JA    0x00
+  BPF_JA    0x00  /* BPF_JMP only */
   BPF_JEQ   0x10
   BPF_JGT   0x20
   BPF_JGE   0x30
@@ -912,8 +912,8 @@ If BPF_CLASS(code) == BPF_JMP, BPF_OP(code) is one of:
   BPF_JNE   0x50  /* eBPF only: jump != */
   BPF_JSGT  0x60  /* eBPF only: signed '>' */
   BPF_JSGE  0x70  /* eBPF only: signed '>=' */
-  BPF_CALL  0x80  /* eBPF only: function call */
-  BPF_EXIT  0x90  /* eBPF only: function return */
+  BPF_CALL  0x80  /* eBPF BPF_JMP only: function call */
+  BPF_EXIT  0x90  /* eBPF BPF_JMP only: function return */
   BPF_JLT   0xa0  /* eBPF only: unsigned '<' */
   BPF_JLE   0xb0  /* eBPF only: unsigned '<=' */
   BPF_JSLT  0xc0  /* eBPF only: signed '<' */
@@ -936,8 +936,9 @@ Classic BPF wastes the whole BPF_RET class to represent a single 'ret'
 operation. Classic BPF_RET | BPF_K means copy imm32 into return register
 and perform function exit. eBPF is modeled to match CPU, so BPF_JMP | BPF_EXIT
 in eBPF means function exit only. The eBPF program needs to store return
-value into register R0 before doing a BPF_EXIT. Class 6 in eBPF is currently
-unused and reserved for future use.
+value into register R0 before doing a BPF_EXIT. Class 6 in eBPF is used as
+BPF_JMP32 to mean exactly the same operations as BPF_JMP, but with 32-bit wide
+operands for the comparisons instead.
 
 For load and store instructions the 8-bit 'code' field is divided as: