[PATCH v1 0/2] Add debug logging and documentation for TLS management

[Frédéric Bérat]

Hello,

This patch series introduces debugging capabilities for Thread-Local
Storage (TLS) management within the dynamic linker and documents the
relevant environment variables.

The first patch adds the `DL_DEBUG_TLS` debug mask, which can be enabled
via the `tls` keyword in the `LD_DEBUG` environment variable. This
provides detailed logging for TCB allocation, deallocation, and reuse,
as well as thread startup events. A new test is included to validate
this functionality.

The second patch adds a new section to the dynamic linker manual,
documenting the `LD_DEBUG` and `LD_DEBUG_OUTPUT` environment variables.
This includes documentation for the newly added `tls` keyword.

These changes enhance the dynamic linker's debuggability for TLS-related
issues and improve the documentation for users. This is a first step,
and the intent is to extend this logging in the future to cover more
aspects of TLS management.

Fred.

Changes since v0:
 - Slightly reworked the test to remove the sleep and quote inputs
 - Updated a few comments for clarity
 - Moved one of the logs before de-allocation

 The 2nd patch is untouched (although I added reviewed-by), but there is
 no point in pushing it yet as it depends on the first.

---
Frédéric Bérat (2):
  tls: Add debug logging for TLS and TCB management
  docs: Add dynamic linker environment variable docs

 elf/dl-tls.c               |  6 ++++
 elf/rtld.c                 |  4 ++-
 manual/dynlink.texi        | 66 ++++++++++++++++++++++++++++++++++
 nptl/Makefile              |  7 ++++
 nptl/allocatestack.c       | 14 ++++++++
 nptl/nptl-stack.c          | 23 ++++++++++--
 nptl/pthread_create.c      |  4 +++
 nptl/tst-dl-debug-tid.c    | 69 ++++++++++++++++++++++++++++++++++++
 nptl/tst-dl-debug-tid.sh   | 72 ++++++++++++++++++++++++++++++++++++++
 sysdeps/generic/ldsodefs.h |  3 +-
 10 files changed, 264 insertions(+), 4 deletions(-)
 create mode 100644 nptl/tst-dl-debug-tid.c
 create mode 100644 nptl/tst-dl-debug-tid.sh

-- 
2.51.0