Fix b/19824366 with a local patch (as upstream is fixed unmergeably), and add a new test.

5 files changed, 175 insertions, 7 deletions

diff --git a/README.google b/README.google
index 9c43bde..cd604a3 100644
--- a/README.google
+++ b/README.google
@@ -452,3 +452,12 @@ misc/sys/cdefs.h
   PLT and improves the performance of some of our code via better icache
   and iTLB performance.
   (tmsriram, google-local)
+
+elf/dl-tls.c
+nptl/Makefile
+nptl/tst-tls77.c
+nptl/tst-tls77mod.c
+  Fix b/19824366 with tweaks to TLS dynamic loading, and add a test.  Note that
+  upstream commit
+  https://sourceware.org/git/?p=glibc.git&a=commit&h=f8aeae347377f3dfa8cbadde057adf1827fb1d44
+  fixes this problem in a different way, so this patch is not needed upstream.
diff --git a/elf/dl-tls.c b/elf/dl-tls.c
index 50ec876..3fbdd45 100644
--- a/elf/dl-tls.c
+++ b/elf/dl-tls.c
@@ -695,10 +695,15 @@ _dl_update_slotinfo (unsigned long int req_modid)
 		   memalign and not malloc.  */
 		__signal_safe_free (dtv[modid].pointer.val);
 
-	      /* This module is loaded dynamically- We defer memory
-		 allocation.  */
-	      dtv[modid].pointer.is_static = false;
-	      dtv[modid].pointer.val = TLS_DTV_UNALLOCATED;
+	      /* Google-local fix for issues solved differently upstream.  */
+	      if (map->l_tls_offset == NO_TLS_OFFSET
+		  || map->l_tls_offset == FORCED_DYNAMIC_TLS_OFFSET)
+		{
+		  /* This module is loaded dynamically- We defer memory
+		     allocation.  */
+		  dtv[modid].pointer.is_static = false;
+		  dtv[modid].pointer.val = TLS_DTV_UNALLOCATED;
+		}
 
 	      if (modid == req_modid)
 		the_map = map;
@@ -769,7 +774,7 @@ tls_get_addr_tail (GET_ADDR_ARGS, dtv_t *dtv, struct link_map *the_map)
     }
   else
     {
-      void **pp = &dtv[GET_ADDR_MODULE].pointer.val;
+      void ** volatile pp = &dtv[GET_ADDR_MODULE].pointer.val;
       while (atomic_forced_read (*pp) == TLS_DTV_UNALLOCATED)
 	{
 	  /* for lack of a better (safe) thing to do, just spin.
diff --git a/nptl/Makefile b/nptl/Makefile
index 4c9015a..f57b0b8 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -300,7 +300,7 @@ tests += tst-cancelx2 tst-cancelx3 tst-cancelx4 tst-cancelx5 \
 endif
 ifeq ($(build-shared),yes)
 tests += tst-atfork2 tst-tls3 tst-tls4 tst-tls5 tst-tls7 tst-_res1 tst-fini1 \
-	 tst-stackguard1
+	 tst-stackguard1 tst-tls77
 tests-nolibpthread += tst-fini1
 ifeq ($(have-z-execstack),yes)
 tests += tst-execstack
@@ -311,7 +311,7 @@ modules-names = tst-atfork2mod tst-tls3mod tst-tls4moda tst-tls4modb \
 		tst-tls5mod tst-tls5moda tst-tls5modb tst-tls5modc \
 		tst-tls5modd tst-tls5mode tst-tls5modf \
 		tst-_res1mod1 tst-_res1mod2 tst-execstack-mod tst-fini1mod \
-		tst-tls7mod
+		tst-tls7mod tst-tls77mod
 extra-test-objs += $(addsuffix .os,$(strip $(modules-names))) tst-cleanup4aux.o
 test-extras += $(modules-names) tst-cleanup4aux
 test-modules = $(addprefix $(objpfx),$(addsuffix .so,$(modules-names)))
@@ -326,6 +326,7 @@ tst-tls5modd.so-no-z-defs = yes
 tst-tls5mode.so-no-z-defs = yes
 tst-tls5modf.so-no-z-defs = yes
 tst-tls7mod.so-no-z-defs = yes
+tst-tls77mod.so-no-z-defs = yes
 
 ifeq ($(build-shared),yes)
 # Build all the modules even when not actually running test programs.
@@ -506,6 +507,11 @@ $(objpfx)tst-tls6.out: tst-tls6.sh $(objpfx)tst-tls5 \
 	  '$(test-wrapper-env)'
 endif
 
+$(objpfx)tst-tls77: $(libdl) $(shared-thread-library)
+LDFLAGS-tst-tls77 = -rdynamic
+$(objpfx)tst-tls77.out: $(objpfx)tst-tls77mod.so
+$(objpfx)tst-tls77mod.so: $(shared-thread-library)
+
 $(objpfx)tst-dlsym1: $(libdl) $(shared-thread-library)
 
 $(objpfx)tst-fini1: $(shared-thread-library) $(objpfx)tst-fini1mod.so
diff --git a/nptl/tst-tls77.c b/nptl/tst-tls77.c
new file mode 100644
index 0000000..84cf21b
--- /dev/null
+++ b/nptl/tst-tls77.c
@@ -0,0 +1,107 @@
+/* Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <dlfcn.h>
+#include <errno.h>
+#include <pthread.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <pthreaddef.h>
+
+static pthread_t th;
+
+pthread_barrier_t b;
+
+void *(*dfp)(void*) = NULL;
+
+void *
+caller(void *x)
+{
+  pthread_barrier_wait (&b);
+
+  if (dfp)
+    dfp(NULL);
+
+  return NULL;
+}
+
+int
+do_test (void)
+{
+  if (pthread_barrier_init (&b, NULL, 2) != 0)
+    {
+      puts ("barrier_init failed");
+      exit (1);
+    }
+
+  pthread_attr_t a;
+
+  if (pthread_attr_init (&a) != 0)
+    {
+      puts ("attr_init failed");
+      exit (1);
+    }
+
+  if (pthread_attr_setstacksize (&a, 1 * 1024 * 1024) != 0)
+    {
+      puts ("attr_setstacksize failed");
+      return 1;
+    }
+
+  if (pthread_create (&th, &a, caller, 0) != 0)
+    {
+      puts ("pthread_create failed");
+      exit (1);
+    }
+
+  void *h = dlopen ("tst-tls77mod.so", RTLD_LAZY);
+  if (h == NULL)
+    {
+      puts ("dlopen failed");
+      exit (1);
+    }
+
+  dfp = dlsym (h, "toucher");
+  if (dfp == NULL)
+    {
+      printf ("dlsym for toucher failed %s\n", dlerror ());
+      return 1;
+    }
+
+  pthread_barrier_wait (&b);
+
+  if (pthread_join (th, NULL) != 0)
+    {
+      puts ("join failed");
+      exit (1);
+    }
+
+  if (pthread_attr_destroy (&a) != 0)
+    {
+      puts ("attr_destroy failed");
+      exit (1);
+    }
+
+  return 0;
+}
+
+
+#define TIMEOUT 5
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
diff --git a/nptl/tst-tls77mod.c b/nptl/tst-tls77mod.c
new file mode 100644
index 0000000..1a541f2
--- /dev/null
+++ b/nptl/tst-tls77mod.c
@@ -0,0 +1,41 @@
+/* Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <pthreaddef.h>
+
+__thread int tlsvar;
+
+__thread int iexecvar __attribute__ ((tls_model ("initial-exec")));
+
+void *
+toucher (void *arg)
+{
+  tlsvar++;
+
+  printf ("tlsvar=%d iexecvar=%d\n", tlsvar, iexecvar);
+
+  iexecvar++;
+
+  printf ("tlsvar=%d iexecvar=%d\n", tlsvar, iexecvar);
+
+  return NULL;
+}