Fix TLS access for -static -pthread

I have posted:
	TLS variables access for -static -lpthread executables
	https://sourceware.org/ml/libc-help/2014-03/msg00024.html
and the GDB patch below has been confirmed as OK for current glibcs.

Further work should be done for newer glibcs:
	Improve TLS variables glibc compatibility
	https://sourceware.org/bugzilla/show_bug.cgi?id=16954

Still the patch below implements the feature in a fully functional way backward
compatible with current glibcs, it depends on the following glibc source line:
	csu/libc-tls.c
	main_map->l_tls_modid = 1;

gdb/
2014-05-21  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Fix TLS access for -static -pthread.
	* linux-thread-db.c (struct thread_db_info): Add td_thr_tlsbase_p.
	(try_thread_db_load_1): Initialize it.
	(thread_db_get_thread_local_address): Call it if LM is zero.
	* target.c (target_translate_tls_address): Remove LM_ADDR zero check.
	* target.h (struct target_ops) (to_get_thread_local_address): Add
	load_module_addr comment.

gdb/gdbserver/
2014-05-21  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Fix TLS access for -static -pthread.
	* gdbserver/thread-db.c (struct thread_db): Add td_thr_tlsbase_p.
	(thread_db_get_tls_address): Call it if LOAD_MODULE is zero.
	(thread_db_load_search, try_thread_db_load_1): Initialize it.

gdb/testsuite/
2014-05-21  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Fix TLS access for -static -pthread.
	* gdb.threads/staticthreads.c <HAVE_TLS> (tlsvar): New.
	<HAVE_TLS> (thread_function, main): Initialize it.
	* gdb.threads/staticthreads.exp: Try gdb_compile_pthreads for $have_tls.
	Add clean_restart.
	<$have_tls != "">: Check TLSVAR.

Message-ID: <20140410115204.GB16411@host2.jankratochvil.net>

3 files changed, 45 insertions, 6 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 1e39142..56b6cc5 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,12 @@
+2014-05-21  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	Fix TLS access for -static -pthread.
+	* gdb.threads/staticthreads.c <HAVE_TLS> (tlsvar): New.
+	<HAVE_TLS> (thread_function, main): Initialize it.
+	* gdb.threads/staticthreads.exp: Try gdb_compile_pthreads for $have_tls.
+	Add clean_restart.
+	<$have_tls != "">: Check TLSVAR.
+
 2014-05-21  Pedro Alves  <palves@redhat.com>
 
 	* gdb.base/dcache-line-read-error.c: New.
diff --git a/gdb/testsuite/gdb.threads/staticthreads.c b/gdb/testsuite/gdb.threads/staticthreads.c
index e834d7f..5c8eabe 100644
--- a/gdb/testsuite/gdb.threads/staticthreads.c
+++ b/gdb/testsuite/gdb.threads/staticthreads.c
@@ -28,10 +28,17 @@
 
 sem_t semaphore;
 
+#ifdef HAVE_TLS
+__thread int tlsvar;
+#endif
+
 void *
 thread_function (void *arg)
 {
-  printf ("Thread executing\n");
+#ifdef HAVE_TLS
+  tlsvar = 2;
+#endif
+  printf ("Thread executing\n"); /* tlsvar-is-set */
   while (sem_wait (&semaphore) != 0)
     {
       if (errno != EINTR)
@@ -57,6 +64,9 @@ main (int argc, char **argv)
       return -1;
     }
 
+#ifdef HAVE_TLS
+  tlsvar = 1;
+#endif
 
   /* Create a thread, wait for it to complete.  */
   {
diff --git a/gdb/testsuite/gdb.threads/staticthreads.exp b/gdb/testsuite/gdb.threads/staticthreads.exp
index 80b0ba8..9fa625a 100644
--- a/gdb/testsuite/gdb.threads/staticthreads.exp
+++ b/gdb/testsuite/gdb.threads/staticthreads.exp
@@ -22,11 +22,16 @@
 standard_testfile
 set static_flag "-static"
 
-if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" \
-	 executable \
-	 [list debug "additional_flags=${static_flag}" \
-	     ]] != "" } {
-    return -1
+foreach have_tls { "-DHAVE_TLS" "" } {
+    if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" \
+	     executable \
+	     [list debug "additional_flags=${static_flag} ${have_tls}" \
+		 ]] == "" } {
+	break
+    }
+    if { $have_tls == "" } {
+	return -1
+    }
 }
 
 clean_restart ${binfile}
@@ -89,3 +94,18 @@ gdb_test_multiple "quit" "$test" {
         pass "$test"
     }
 }
+clean_restart ${binfile}
+
+
+if { "$have_tls" != "" } {
+    if ![runto_main] {
+	return -1
+    }
+    gdb_breakpoint [gdb_get_line_number "tlsvar-is-set"]
+    gdb_continue_to_breakpoint "tlsvar-is-set" ".* tlsvar-is-set .*"
+    gdb_test "p tlsvar" " = 2" "tlsvar in thread"
+    gdb_test "thread 1" ".*"
+    # Unwind from pthread_join.
+    gdb_test "up 10" " in main .*"
+    gdb_test "p tlsvar" " = 1" "tlsvar in main"
+}