Thread (8 messages) read the whole thread 8 messages, 2 authors, 2021-01-18
STALE2023d

Revision v3 of 4 in this series.

Revisions (4)
  1. v2 [diff vs current]
  2. v2 [diff vs current]
  3. v3 current
  4. v4 [diff vs current]

[PATCH v3 0/3] bpf,x64: implement jump padding in jit

From: Gary Lin <hidden>
Date: 2021-01-14 09:56:00
Also in: bpf

This patch series implements jump padding to x64 jit to cover some
corner cases that used to consume more than 20 jit passes and caused
failure.

v3:
  - Copy the instructions of prologue separately or the size calculation
    of the first BPF instruction would include the prologue.
  - Replace WARN_ONCE() with pr_err() and EFAULT
  - Use MAX_PASSES in the for loop condition check
  - Remove the "padded" flag from x64_jit_data. For the extra pass of
    subprogs, padding is always enabled since it won't hurt the images
    that converge without padding.
v2:
  - Simplify the sample code in the commit description and provide the
    jit code
  - Check the expected padding bytes with WARN_ONCE
  - Move the 'padded' flag to 'struct x64_jit_data'
  - Remove the EXPECTED_FAIL flag from bpf_fill_maxinsns11() in test_bpf
  - Add 2 verifier tests

Gary Lin (3):
  bpf,x64: pad NOPs to make images converge more easily
  test_bpf: remove EXPECTED_FAIL flag from bpf_fill_maxinsns11
  selftests/bpf: Add verifier test for x64 jit jump padding

 arch/x86/net/bpf_jit_comp.c                 | 86 +++++++++++++++------
 lib/test_bpf.c                              |  7 +-
 tools/testing/selftests/bpf/test_verifier.c | 43 +++++++++++
 tools/testing/selftests/bpf/verifier/jit.c  | 16 ++++
 4 files changed, 122 insertions(+), 30 deletions(-)

-- 
2.29.2



Gary Lin (3):
  bpf,x64: pad NOPs to make images converge more easily
  test_bpf: remove EXPECTED_FAIL flag from bpf_fill_maxinsns11
  selftests/bpf: Add verifier test for x64 jit jump padding

 arch/x86/net/bpf_jit_comp.c                 | 103 ++++++++++++++------
 lib/test_bpf.c                              |   7 +-
 tools/testing/selftests/bpf/test_verifier.c |  43 ++++++++
 tools/testing/selftests/bpf/verifier/jit.c  |  16 +++
 4 files changed, 135 insertions(+), 34 deletions(-)

-- 
2.29.2
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