[PATCH v2 0/2] Fix trace remotes read with an offline CPU

[Vincent Donnefort <vdonnefort@google.com>]

This small series is fixing non-consuming read of a trace remote when the
trace_buffer is created after a CPU is offline.

It also extends hotplug testing coverage to include this test case.

I have based this series on top of kvmarm/next which contains the hypervisor
tracing patches.

Changes in v2:

 * Add a trap to restore offlined CPU on test failure in hotplug.tc.
 * Fix assert_loaded/assert_unloaded error propagation.
 * Ensure we probe for existing events when setting up consuming read
   iterator.

v1: https://lore.kernel.org/all/20260401025003.3258729-1-vdonnefort@google.com/

Vincent Donnefort (2):
  tracing: Non-consuming read for trace remotes with an offline CPU
  tracing: selftests: Extend hotplug testing for trace remotes

 kernel/trace/trace_remote.c                   | 22 ++++-
 .../selftests/ftrace/test.d/remotes/functions | 19 +++-
 .../ftrace/test.d/remotes/hotplug.tc          | 88 +++++++++++++++++++
 .../test.d/remotes/hypervisor/hotplug.tc      | 11 +++
 .../selftests/ftrace/test.d/remotes/trace.tc  | 27 +-----
 .../ftrace/test.d/remotes/trace_pipe.tc       | 25 ------
 6 files changed, 134 insertions(+), 58 deletions(-)
 create mode 100644 tools/testing/selftests/ftrace/test.d/remotes/hotplug.tc
 create mode 100644 tools/testing/selftests/ftrace/test.d/remotes/hypervisor/hotplug.tc


base-commit: 5ad2ff071b5980f072a85c8114649218971c586e
-- 
2.53.0.1118.gaef5881109-goog