Artem Savkov d9815bff6b ftrace: Return the first found result in lookup_rec() ...

It appears that ip ranges can overlap so. In that case lookup_rec()
returns whatever results it got last even if it found nothing in last
searched page.

This breaks an obscure livepatch late module patching usecase:
  - load livepatch
  - load the patched module
  - unload livepatch
  - try to load livepatch again

To fix this return from lookup_rec() as soon as it found the record
containing searched-for ip. This used to be this way prior lookup_rec()
introduction.

Link: http://lkml.kernel.org/r/20200306174317.21699-1-asavkov@redhat.com

Cc: stable@vger.kernel.org
Fixes: 7e16f581a8 ("ftrace: Separate out functionality from ftrace_location_range()")
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

2020-03-11 10:37:12 -04:00

171 KiB

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