Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2023-05-26

We've added 54 non-merge commits during the last 10 day(s) which contain
a total of 76 files changed, 2729 insertions(+), 1003 deletions(-).

The main changes are:

1) Add the capability to destroy sockets in BPF through a new kfunc,
   from Aditi Ghag.

2) Support O_PATH fds in BPF_OBJ_PIN and BPF_OBJ_GET commands,
   from Andrii Nakryiko.

3) Add capability for libbpf to resize datasec maps when backed via mmap,
   from JP Kobryn.

4) Move all the test kfuncs for CI out of the kernel and into bpf_testmod,
   from Jiri Olsa.

5) Big batch of xsk selftest improvements to prep for multi-buffer testing,
   from Magnus Karlsson.

6) Show the target_{obj,btf}_id in tracing link's fdinfo and dump it
   via bpftool, from Yafang Shao.

7) Various misc BPF selftest improvements to work with upcoming LLVM 17,
   from Yonghong Song.

8) Extend bpftool to specify netdevice for resolving XDP hints,
   from Larysa Zaremba.

9) Document masking in shift operations for the insn set document,
   from Dave Thaler.

10) Extend BPF selftests to check xdp_feature support for bond driver,
    from Lorenzo Bianconi.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits)
  bpf: Fix bad unlock balance on freeze_mutex
  libbpf: Ensure FD >= 3 during bpf_map__reuse_fd()
  libbpf: Ensure libbpf always opens files with O_CLOEXEC
  selftests/bpf: Check whether to run selftest
  libbpf: Change var type in datasec resize func
  bpf: drop unnecessary bpf_capable() check in BPF_MAP_FREEZE command
  libbpf: Selftests for resizing datasec maps
  libbpf: Add capability for resizing datasec maps
  selftests/bpf: Add path_fd-based BPF_OBJ_PIN and BPF_OBJ_GET tests
  libbpf: Add opts-based bpf_obj_pin() API and add support for path_fd
  bpf: Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands
  libbpf: Start v1.3 development cycle
  bpf: Validate BPF object in BPF_OBJ_PIN before calling LSM
  bpftool: Specify XDP Hints ifname when loading program
  selftests/bpf: Add xdp_feature selftest for bond device
  selftests/bpf: Test bpf_sock_destroy
  selftests/bpf: Add helper to get port using getsockname
  bpf: Add bpf_sock_destroy kfunc
  bpf: Add kfunc filter function to 'struct btf_kfunc_id_set'
  bpf: udp: Implement batching for sockets iterator
  ...
====================

Link: https://lore.kernel.org/r/20230526222747.17775-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/Documentation/bpf/instruction-set.rst b/Documentation/bpf/instruction-set.rst
index 492980ece1ab..6644842cd3ea 100644
--- a/Documentation/bpf/instruction-set.rst
+++ b/Documentation/bpf/instruction-set.rst
@@ -163,13 +163,13 @@ BPF_MUL   0x20   dst \*= src
 BPF_DIV   0x30   dst = (src != 0) ? (dst / src) : 0
 BPF_OR    0x40   dst \|= src
 BPF_AND   0x50   dst &= src
-BPF_LSH   0x60   dst <<= src
-BPF_RSH   0x70   dst >>= src
+BPF_LSH   0x60   dst <<= (src & mask)
+BPF_RSH   0x70   dst >>= (src & mask)
 BPF_NEG   0x80   dst = ~src
 BPF_MOD   0x90   dst = (src != 0) ? (dst % src) : dst
 BPF_XOR   0xa0   dst ^= src
 BPF_MOV   0xb0   dst = src
-BPF_ARSH  0xc0   sign extending shift right
+BPF_ARSH  0xc0   sign extending dst >>= (src & mask)
 BPF_END   0xd0   byte swap operations (see `Byte swap instructions`_ below)
 ========  =====  ==========================================================
 
@@ -204,6 +204,9 @@ for ``BPF_ALU64``, 'imm' is first sign extended to 64 bits and the result
 interpreted as an unsigned 64-bit value. There are no instructions for
 signed division or modulo.
 
+Shift operations use a mask of 0x3F (63) for 64-bit operations and 0x1F (31)
+for 32-bit operations.
+
 Byte swap instructions
 ~~~~~~~~~~~~~~~~~~~~~~