[PATCH 0/7] uprobes/x86: Fix red zone issue for optimized uprobes

[Jiri Olsa <jolsa@kernel.org>]

hi,
Andrii reported an issue with optimized uprobes [1] that can clobber
redzone area with call instruction storing return address on stack
where user code may keep temporary data without adjusting rsp.

Fixing this by moving the optimized uprobes on top of 10-bytes nop
instruction, so we can squeeze another instruction to escape the
redzone area before doing the call.

Note we need upstream update first for patch 3 (github.com/libbpf/usdt),
if we decide to take this change.

thanks,
jirka


[1] https://lore.kernel.org/bpf/20260509003146.976844-1-andrii@kernel.org/
---
Andrii Nakryiko (1):
      selftests/bpf: Add tests for uprobe nop10 red zone clobbering

Jiri Olsa (6):
      uprobes/x86: Move optimized uprobe from nop5 to nop10
      libbpf: Change has_nop_combo to work on top of nop10
      selftests/bpf: Emit nop,nop10 instructions combo for x86_64 arch
      selftests/bpf: Change uprobe syscall tests to use nop10
      selftests/bpf: Change uprobe/usdt trigger bench code to use nop10
      selftests/bpf: Add reattach tests for uprobe syscall

 arch/x86/kernel/uprobes.c                               | 121 ++++++++++++++++++++++++++++------------
 tools/lib/bpf/usdt.c                                    |  16 +++---
 tools/testing/selftests/bpf/bench.c                     |  20 +++----
 tools/testing/selftests/bpf/benchs/bench_trigger.c      |  38 ++++++-------
 tools/testing/selftests/bpf/benchs/run_bench_uprobes.sh |   2 +-
 tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c | 217 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------
 tools/testing/selftests/bpf/prog_tests/usdt.c           |  74 +++++++++++++++++++++----
 tools/testing/selftests/bpf/progs/test_usdt.c           |  25 +++++++++
 tools/testing/selftests/bpf/usdt.h                      |   2 +-
 tools/testing/selftests/bpf/usdt_2.c                    |  15 ++++-
 10 files changed, 423 insertions(+), 107 deletions(-)