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From: Yonghong Song <yhs@fb.com>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>, <kernel-team@fb.com>
Subject: [PATCH bpf-next 0/2] bpf: permit map_ptr arithmetic with opcode add and offset 0
Date: Fri, 4 Sep 2020 12:49:00 -0700	[thread overview]
Message-ID: <20200904194900.3031319-1-yhs@fb.com> (raw)

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


             reply	other threads:[~2020-09-04 19:49 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-04 19:49 Yonghong Song [this message]
2020-09-04 19:49 ` [PATCH bpf-next 1/2] " Yonghong Song
2020-09-04 20:30   ` Andrii Nakryiko
2020-09-04 23:20     ` Yonghong Song
2020-09-05  0:08       ` Andrii Nakryiko
2020-09-05  0:10         ` Alexei Starovoitov
2020-09-07 14:21           ` Daniel Borkmann
2020-09-04 19:49 ` [PATCH bpf-next 2/2] selftests/bpf: add test for map_ptr arithmetic Yonghong Song

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