netdev - [PATCH bpf-next 0/2] bpf: permit map_ptr arithmetic with opcode add and offset 0

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Date:   Fri, 4 Sep 2020 12:49:00 -0700
From:   Yonghong Song <yhs@...com>
To:     <bpf@...r.kernel.org>, <netdev@...r.kernel.org>
CC:     Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>, <kernel-team@...com>
Subject: [PATCH bpf-next 0/2] bpf: permit map_ptr arithmetic with opcode add and offset 0

With CORE, it is possible that the compiler may produce code like
  r1 = 0  // relocation instruction
  map_ptr += r1
  ...
Currently verifier does not allow map_ptr arithmetic, even for adding with 0.
This patch set relaxed the condition so the above code can be accepted.
Patch #1 is the kernel implementation and Patch #2 added selftest tests to
cover the new functionality.

Yonghong Song (2):
  bpf: permit map_ptr arithmetic with opcode add and offset 0
  selftests/bpf: add test for map_ptr arithmetic

 kernel/bpf/verifier.c                         |  3 ++
 .../selftests/bpf/progs/map_ptr_kern.c        |  4 +--
 .../testing/selftests/bpf/verifier/map_ptr.c  | 32 +++++++++++++++++++
 3 files changed, 37 insertions(+), 2 deletions(-)

-- 
2.24.1