[PATCHv2 perf/core 0/4] uprobe,bpf: Allow to change app registers from uprobe registers

[Jiri Olsa <jolsa@kernel.org>]

hi,
we recently had several requests for tetragon to be able to change
user application function return value or divert its execution through
instruction pointer change.

This patchset adds support for uprobe program to change app's registers
including instruction pointer.

v2 changes:
- moving back to original change without the uniqeu/exclusive flag
  as discussed in here [1]

thanks,
jirka


[1] https://lore.kernel.org/bpf/CAEf4BzbxjRwxhJTLUgJNwR-vEbDybBpawNsRb+y+PiDsxzT=eA@mail.gmail.com/
---
Jiri Olsa (4):
      bpf: Allow uprobe program to change context registers
      uprobe: Do not emulate/sstep original instruction when ip is changed
      selftests/bpf: Add uprobe context registers changes test
      selftests/bpf: Add uprobe context ip register change test

 include/linux/bpf.h                             |   1 +
 kernel/events/core.c                            |   4 +++
 kernel/events/uprobes.c                         |   7 +++++
 kernel/trace/bpf_trace.c                        |   3 +-
 tools/testing/selftests/bpf/prog_tests/uprobe.c | 156 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 tools/testing/selftests/bpf/progs/test_uprobe.c |  38 +++++++++++++++++++++++++
 6 files changed, 206 insertions(+), 3 deletions(-)