commit ffaf6f0eed3d751c929575d337e1c4da5f8b313c
author Caslyn Tonelli <caslyn@google.com> Wed Oct 30 00:55:48 2024 +0000
committer CQ Bot <fuchsia-internal-scoped@luci-project-accounts.iam.gserviceaccount.com> Wed Oct 30 00:55:48 2024 +0000
tree 95de70d437f521befd927c717aac1c630dc304a2
parent 186bd573c148cd6d4e84ae1c1e45f73ba1642677

[dl] Support RTLD_GLOBAL

This CL supports the RTLD_GLOBAL flag with dlopen(). The root
RuntimeModule and all its dependencies (either previously loaded or new
to the session) are marked as global when dlopen-ed with this flag.

This action may rearrange the "global load order" of modules: that is,
the order in which modules loaded with RTLD_GLOBAL are kept in the
dynamic linker's modules_ list.

This CL does not yet include global modules in symbol resolution, but
tests are introduced to test the following behavior in regards to how
global modules relate to load order:

- Promote previously loaded module and all its deps to become global.
- Promoting a previously loaded module to a global module can change the
  "global load order" of modules
- Calling dlopen(RTLD_GLOBAL) multiple times on a module will not change
  the "global load order".
- Calling dlopen(RTLD_GLOBAL) with previously loaded global modules will
  not change the "global load order".

A forthcoming CL will include global modules in symbol relocations and
tests will be enabled then.

Bug: 338233824
Cq-Include-Trybots: luci.turquoise.global.try:run-postsubmit-tryjobs
Change-Id: I6a21146c48cdd82983cc7bb19040ac8954fe512a
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1124721
Fuchsia-Auto-Submit: Caslyn Tonelli <caslyn@google.com>
Commit-Queue: Auto-Submit <auto-submit@fuchsia-infra.iam.gserviceaccount.com>
Reviewed-by: Roland McGrath <mcgrathr@google.com>