[bpf,0/5] Fix BPF multi-uprobe PID filtering logic

Message

Andrii Nakryiko May 20, 2024, 11:47 p.m. UTC

It turns out that current implementation of multi-uprobe PID filtering logic
is broken. It filters by thread, while the promise is filtering by process.
Patch #1 fixes the logic trivially. The rest is testing and mitigations that
are necessary for libbpf to not break users of USDT programs.

Andrii Nakryiko (5):
  bpf: fix multi-uprobe PID filtering logic
  bpf: remove unnecessary rcu_read_{lock,unlock}() in multi-uprobe
    attach logic
  libbpf: detect broken PID filtering logic for multi-uprobe
  selftests/bpf: extend multi-uprobe tests with child thread case
  selftests/bpf: extend multi-uprobe tests with USDTs

 kernel/trace/bpf_trace.c                      |  10 +-
 tools/lib/bpf/features.c                      |  31 ++++-
 .../bpf/prog_tests/uprobe_multi_test.c        | 131 ++++++++++++++++--
 .../selftests/bpf/progs/uprobe_multi.c        |  50 ++++++-
 4 files changed, 203 insertions(+), 19 deletions(-)