[PATCH 11/11] Add TLS NEWS entry and document 'set force-internal-tls-address-lookup' command

[Kevin Buettner <kevinb@redhat.com>]

---
 gdb/NEWS            | 20 ++++++++++++++++++++
 gdb/doc/gdb.texinfo | 17 +++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/gdb/NEWS b/gdb/NEWS
index 42668cbc057..dcb24eb5248 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -63,6 +63,26 @@
      the return value from the latest "stepOut" command, when
      appropriate.
 
+* GDB-internal TLS support
+
+  ** Linux targets for the x86_64, aarch64, ppc64, s390x, and riscv
+     architectures now have GDB-internal support for TLS address
+     lookup in addition to that traditionally provided by the
+     libthread_db library.  This internal support works for programs
+     linked against either the GLIBC or MUSL C libraries.  For
+     programs linked against MUSL, this new internal support provides
+     new debug functionality, allowing access to TLS variables, due to
+     the fact that MUSL does not implement the libthread_db library. 
+     Internal TLS support is also useful in cross-debugging
+     situations, debugging statically linked binaries, and debugging
+     programs linked against GLIBC 2.33 and earlier, but which are not
+     linked against libpthread.
+
+  ** The command 'set force-internal-tls-address-lookup on' may be
+     used to force the internal TLS lookup mechanisms to be used.
+     Otherwise, TLS lookup via libthread_db will still be preferred,
+     when available.
+
 * New commands
 
 set style line-number foreground COLOR
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 46ca62ec0c3..f0f98061a1f 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -4067,6 +4067,23 @@ only on some platforms.
 @item show libthread-db-search-path 
 Display current libthread_db search path.
 
+@kindex set force-internal-tls-address-lookup
+@kindex show force-internal-tls-address-lookup
+@cindex internal TLS lookup
+Turns on or off forced use of @value{GDBN}-internal TLS (Thread Local
+Storage) address lookup code.  Use @code{on} to enable and @code{0} to
+disable.
+
+When disabled, @value{GDBN} will attempt to use a helper
+@code{libthread_db} library if possible, but will fall back to use of
+its own internal TLS address lookup mechanisms if necessary.
+
+When enabled, @value{GDBN} will only use the @value{GDBN}'s internal
+TLS address lookup mechanisms, if they exist.
+
+This command is only available on targets for which internal TLS
+address lookup support exists.
+
 @kindex set debug libthread-db
 @kindex show debug libthread-db
 @cindex debugging @code{libthread_db}
-- 
2.46.2