[bpf,v2,0/2] Check the remaining info_cnt before repeating btf fields

Message

Hou Tao Sept. 14, 2024, 1:37 p.m. UTC

From: Hou Tao <[e-mail]>

Hi,

The patch set adds the missed check again info_cnt when flattening the
array of nested struct. The problem was spotted when developing dynptr
key support for hash map. Patch #1 adds the missed check and patch #2
adds three success test cases and one failure test case for the problem.

Comments are always welcome.

Change Log:
v2:
 * patch #1: check info_cnt in btf_repeat_fields()
 * patch #2: use a hard-coded number instead of BTF_FIELDS_MAX, because
             BTF_FIELDS_MAX is not always available in vmlinux.h (e.g.,
	     for llvm 17/18)

v1: https://lore.kernel.org/bpf/[e-mail]/T/#t

Hou Tao (2):
  bpf: Check the remaining info_cnt before repeating btf fields
  selftests/bpf: Add more test case for field flattening

 kernel/bpf/btf.c                              | 14 +++-
 .../selftests/bpf/prog_tests/cpumask.c        |  1 +
 .../selftests/bpf/progs/cpumask_common.h      |  5 ++
 .../selftests/bpf/progs/cpumask_failure.c     | 35 +++++++++
 .../selftests/bpf/progs/cpumask_success.c     | 78 ++++++++++++++++++-
 5 files changed, 127 insertions(+), 6 deletions(-)