[patch] glibc-2.3.4-fix-_dl_next_tls_modid-assert.patch

glibc-2.3.4-fix-_dl_next_tls_modid-assert.patch (text/plain), 8.93 KB, created by Martin Schlemmer (RETIRED) on 2005-03-15 07:46:11 UTC

Gentoo bug #52374.
==================

Note, this patch includes both:

-----
2005-01-10  Ulrich Drepper  <[e-mail]>

        * sysdeps/generic/dl-tls.c (_dl_next_tls_modid): Fix assertion and
        recognition of last entry.
-----

and:

-----
2005-03-15  Jakub Jelinek  <[e-mail]>

        [BZ#786]
        * sysdeps/generic/dl-tls.c (_dl_next_tls_modid): Handle
        GL(dl_tls_static_nelem) == GL(dl_tls_max_dtv_idx).
        * elf/Makefile: Add rules to build and run tst-tls15.
        * elf/tst-tls15.c: New test.
        * elf/tst-tlsmod15a.c: New file.
        * elf/tst-tlsmod15b.c: New file.
-----

================================================================================
On Sun, Mar 13, 2005 at 09:39:04PM +0200, Martin Schlemmer wrote:
> Basically the issue above.  This is valid for glibc 2.3.[234] if I did
> not miss anything.  Here is a good test case:
> 
> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=219352#msg122
> 
> I came up with attached patch that seems to work and passes all the
> tests (except for the one or two usual ones).  Is this the correct fix,
> or are the problem deeper?
>
>--- glibc-2.3.4/sysdeps/generic/dl-tls.c.az	2005-03-13 19:26:55.000000000 +0200
>+++ glibc-2.3.4/sysdeps/generic/dl-tls.c	2005-03-13 19:29:14.000000000 +0200
>@@ -69,7 +69,10 @@
>       result = GL(dl_tls_static_nelem) + 1;
>       /* If the following would not be true we mustn't have assumed
> 	 there is a gap.  */
>-      assert (result <= GL(dl_tls_max_dtv_idx));
>+      /* The +1 is needed, as we add +1 above, but dl_tls_static_nelem
>+         is only once set as far as I can see in dl_main (elf/rtld.c),
>+         and that is equal to dl_tls_max_dtv_idx ... */
>+      assert (result <= (GL(dl_tls_max_dtv_idx) + 1));
>       do
> 	{
> 	  while (result - disp < runp->len)
>@@ -92,7 +95,8 @@
> 	{
> 	  /* The new index must indeed be exactly one higher than the
> 	     previous high.  */
>-	  assert (result == GL(dl_tls_max_dtv_idx));
>+	  /* Once again +1 for the same reasons as above ... */
>+	  assert (result == (GL(dl_tls_max_dtv_idx) + 1));
> 
> 	  /* There is no gap anymore.  */
> 	  GL(dl_tls_dtv_gaps) = false;
>

That patch certainly doesn't apply to neither HEAD nor glibc-2_3-branch,
see especially:
2005-01-10  Ulrich Drepper  <[e-mail]>

        * sysdeps/generic/dl-tls.c (_dl_next_tls_modid): Fix assertion and
        recognition of last entry.

The fix can either be that dl-open.c only sets GL(dl_tls_dtv_gaps)
to true if GL(dl_tls_static_nelem) < GL(dl_tls_max_dtv_idx)
(if it is equal, there are certainly no gaps), or handling that case
in _dl_next_tls_modid.  In _dl_next_tls_modid, the choices are either
to do what the patch below does, i.e. just clear GL(dl_tls_dtv_gaps)
if that happens, or just change the assert and let the do ... while
loop run, it shouldn't increment result anyway.

2005-03-15  Jakub Jelinek  <[e-mail]>

        [BZ#786]
        * sysdeps/generic/dl-tls.c (_dl_next_tls_modid): Handle
        GL(dl_tls_static_nelem) == GL(dl_tls_max_dtv_idx).
        * elf/Makefile: Add rules to build and run tst-tls15.
        * elf/tst-tls15.c: New test.
        * elf/tst-tlsmod15a.c: New file.
        * elf/tst-tlsmod15b.c: New file.

diff -urpN glibc-2.3.4.az/elf/Makefile glibc-2.3.4/elf/Makefile
--- glibc-2.3.4.az/elf/Makefile	2005-03-15 17:38:36.000000000 +0200
+++ glibc-2.3.4/elf/Makefile	2005-03-15 17:39:07.000000000 +0200
@@ -152,7 +152,7 @@ tests += loadtest restest1 preloadtest l
 	 neededtest3 neededtest4 unload2 lateglobal initfirst global \
 	 restest2 next dblload dblunload reldep5 reldep6 reldep7 reldep8 \
 	 circleload1 tst-tls3 tst-tls4 tst-tls5 tst-tls6 tst-tls7 tst-tls8 \
-	 tst-tls10 tst-tls11 tst-tls12 tst-tls13 tst-tls14 tst-align \
+	 tst-tls10 tst-tls11 tst-tls12 tst-tls13 tst-tls14 tst-tls15 tst-align \
 	 $(tests-execstack-$(have-z-execstack)) tst-dlmodcount \
 	 tst-dlopenrpath tst-deep1 tst-dlmopen1 tst-dlmopen2 tst-dlmopen3
 #	 reldep9
@@ -182,6 +182,7 @@ modules-names = testobj1 testobj2 testob
 		tst-tlsmod5 tst-tlsmod6 tst-tlsmod7 tst-tlsmod8 \
 		tst-tlsmod9 tst-tlsmod10 tst-tlsmod11 tst-tlsmod12 \
 		tst-tlsmod13 tst-tlsmod13a tst-tlsmod14a tst-tlsmod14b \
+		tst-tlsmod15a tst-tlsmod15b \
 		circlemod1 circlemod1a circlemod2 circlemod2a \
 		circlemod3 circlemod3a \
 		reldep8mod1 reldep8mod2 reldep8mod3 \
@@ -454,6 +455,7 @@ tst-tlsmod10.so-no-z-defs = yes
 tst-tlsmod12.so-no-z-defs = yes
 tst-tlsmod14a.so-no-z-defs = yes
 tst-tlsmod14b.so-no-z-defs = yes
+tst-tlsmod15a.so-no-z-defs = yes
 circlemod2.so-no-z-defs = yes
 circlemod3.so-no-z-defs = yes
 circlemod3a.so-no-z-defs = yes
@@ -664,8 +666,11 @@ $(objpfx)tst-tls12: $(objpfx)tst-tlsmod1
 $(objpfx)tst-tls13: $(libdl)
 $(objpfx)tst-tls13.out: $(objpfx)tst-tlsmod13a.so
 
-$(objpfx)tst-tls14:  $(objpfx)tst-tlsmod14a.so $(libdl)
-$(objpfx)tst-tls14.out:$(objpfx)tst-tlsmod14b.so
+$(objpfx)tst-tls14: $(objpfx)tst-tlsmod14a.so $(libdl)
+$(objpfx)tst-tls14.out: $(objpfx)tst-tlsmod14b.so
+
+$(objpfx)tst-tls15: $(libdl)
+$(objpfx)tst-tls15.out: $(objpfx)tst-tlsmod15a.so $(objpfx)tst-tlsmod15b.so
 
 CFLAGS-tst-align.c = $(stack-align-test-flags)
 CFLAGS-tst-alignmod.c = $(stack-align-test-flags)
diff -urpN glibc-2.3.4.az/elf/tst-tls15.c glibc-2.3.4/elf/tst-tls15.c
--- glibc-2.3.4.az/elf/tst-tls15.c	1970-01-01 02:00:00.000000000 +0200
+++ glibc-2.3.4/elf/tst-tls15.c	2005-03-15 17:39:07.000000000 +0200
@@ -0,0 +1,32 @@
+#include <dlfcn.h>
+#include <stdio.h>
+
+static int
+do_test (void)
+{
+  void *h = dlopen ("tst-tlsmod15a.so", RTLD_NOW);
+  if (h != NULL)
+    {
+      puts ("unexpectedly succeeded to open tst-tlsmod15a.so");
+      exit (1);
+    }
+
+  h = dlopen ("tst-tlsmod15b.so", RTLD_NOW);
+  if (h == NULL)
+    {
+      puts ("failed to open tst-tlsmod15b.so");
+      exit (1);
+    }
+
+  int (*fp) (void) = (int (*) (void)) dlsym (h, "in_dso");
+  if (fp == NULL)
+    {
+      puts ("cannot find in_dso");
+      exit (1);
+    }
+
+  return fp ();
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
diff -urpN glibc-2.3.4.az/elf/tst-tlsmod15a.c glibc-2.3.4/elf/tst-tlsmod15a.c
--- glibc-2.3.4.az/elf/tst-tlsmod15a.c	1970-01-01 02:00:00.000000000 +0200
+++ glibc-2.3.4/elf/tst-tlsmod15a.c	2005-03-15 17:39:07.000000000 +0200
@@ -0,0 +1,6 @@
+extern int nonexistent_dummy_var;
+int *
+foo (void)
+{
+  return &nonexistent_dummy_var;
+}
diff -urpN glibc-2.3.4.az/elf/tst-tlsmod15b.c glibc-2.3.4/elf/tst-tlsmod15b.c
--- glibc-2.3.4.az/elf/tst-tlsmod15b.c	1970-01-01 02:00:00.000000000 +0200
+++ glibc-2.3.4/elf/tst-tlsmod15b.c	2005-03-15 17:39:07.000000000 +0200
@@ -0,0 +1,17 @@
+#include "tst-tls10.h"
+
+#ifdef USE_TLS__THREAD
+__thread int mod15b_var __attribute__((tls_model("initial-exec")));
+
+int
+in_dso (void)
+{
+  return mod15b_var;
+}
+#else
+int
+in_dso (void)
+{
+  return 0;
+}
+#endif
diff -urpN glibc-2.3.4.az/sysdeps/generic/dl-tls.c glibc-2.3.4/sysdeps/generic/dl-tls.c
--- glibc-2.3.4.az/sysdeps/generic/dl-tls.c	2005-03-15 17:40:56.000000000 +0200
+++ glibc-2.3.4/sysdeps/generic/dl-tls.c	2005-03-15 17:39:07.000000000 +0200
@@ -65,34 +65,35 @@ _dl_next_tls_modid (void)
       /* Note that this branch will never be executed during program
 	 start since there are no gaps at that time.  Therefore it
 	 does not matter that the dl_tls_dtv_slotinfo is not allocated
-	 yet when the function is called for the first times.  */
-      result = GL(dl_tls_static_nelem) + 1;
-      /* If the following would not be true we mustn't have assumed
-	 there is a gap.  */
-      assert (result <= GL(dl_tls_max_dtv_idx));
-      do
-	{
-	  while (result - disp < runp->len)
-	    {
-	      if (runp->slotinfo[result - disp].map == NULL)
-		break;
-
-	      ++result;
-	      assert (result <= GL(dl_tls_max_dtv_idx) + 1);
-	    }
+	 yet when the function is called for the first times.
 
-	  if (result - disp < runp->len)
-	    break;
-
-	  disp += runp->len;
-	}
-      while ((runp = runp->next) != NULL);
+	 NB: the offset +1 is due to the fact that DTV[0] is used
+	 for something else.  */
+      result = GL(dl_tls_static_nelem) + 1;
+      if (result <= GL(dl_tls_max_dtv_idx))
+	do
+	  {
+	    while (result - disp < runp->len)
+	      {
+		if (runp->slotinfo[result - disp].map == NULL)
+		  break;
+
+		++result;
+		assert (result <= GL(dl_tls_max_dtv_idx) + 1);
+	      }
+
+	    if (result - disp < runp->len)
+	      break;
+
+	    disp += runp->len;
+	  }
+	while ((runp = runp->next) != NULL);
 
-      if (result >= GL(dl_tls_max_dtv_idx))
+      if (result > GL(dl_tls_max_dtv_idx))
 	{
 	  /* The new index must indeed be exactly one higher than the
 	     previous high.  */
-	  assert (result == GL(dl_tls_max_dtv_idx));
+	  assert (result == GL(dl_tls_max_dtv_idx) + 1);
 
 	  /* There is no gap anymore.  */
 	  GL(dl_tls_dtv_gaps) = false;
@@ -577,7 +578,7 @@ __tls_get_addr (GET_ADDR_ARGS)
 	    {
 	      size_t cnt;
 
-	      for (cnt = total = 0 ? 1 : 0; cnt < listp->len; ++cnt)
+	      for (cnt = total == 0 ? 1 : 0; cnt < listp->len; ++cnt)
 		{
 		  size_t gen = listp->slotinfo[cnt].gen;
 		  struct link_map *map;