* elf/tst-tls4.c: Define an unused TLS variable here, so that no lazy

	TLS setup is required.
	* elf/tst-tls5.c: Likewise.
	* elf/tst-tls6.c: Likewise.
	* elf/tst-tls7.c: Likewise.
	* elf/tst-tls8.c: Likewise.
	* elf/tst-tls9.c: Likewise.

	* elf/rtld.c (dl_main): Remove [! SHARED] conditional from
	`if (GL(dl_tls_max_dtv_idx) > 0)' tests for doing TLS setup.
	* elf/dl-close.c (libc_freeres_fn): Check GL(dl_tls_dtv_slotinfo_list)
	for being null before calling free_slotinfo.
	* elf/dl-load.c (_dl_map_object_from_fd) [SHARED]: For PT_TLS in
	dynamic loading, bail with error if GL(dl_tls_max_dtv_idx) is zero.

12 files changed, 143 insertions, 23 deletions

diff --git a/ChangeLog b/ChangeLog
index bbdfda3..593f6a6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,20 @@
+2002-12-02  Roland McGrath  <roland@redhat.com>
+
+	* elf/tst-tls4.c: Define an unused TLS variable here, so that no lazy
+	TLS setup is required.
+	* elf/tst-tls5.c: Likewise.
+	* elf/tst-tls6.c: Likewise.
+	* elf/tst-tls7.c: Likewise.
+	* elf/tst-tls8.c: Likewise.
+	* elf/tst-tls9.c: Likewise.
+
+	* elf/rtld.c (dl_main): Remove [! SHARED] conditional from
+	`if (GL(dl_tls_max_dtv_idx) > 0)' tests for doing TLS setup.
+	* elf/dl-close.c (libc_freeres_fn): Check GL(dl_tls_dtv_slotinfo_list)
+	for being null before calling free_slotinfo.
+	* elf/dl-load.c (_dl_map_object_from_fd) [SHARED]: For PT_TLS in
+	dynamic loading, bail with error if GL(dl_tls_max_dtv_idx) is zero.
+
 2002-11-30  Bruno Haible  <bruno@clisp.org>
 
 	* iconv/gconv.h (__gconv_btowc_fct): New typedef.
diff --git a/elf/dl-close.c b/elf/dl-close.c
index 632f8ba..b5c2841 100644
--- a/elf/dl-close.c
+++ b/elf/dl-close.c
@@ -476,12 +476,15 @@ libc_freeres_fn (free_mem)
     }
 
 #ifdef USE_TLS
-  /* Free the memory allocated for the dtv slotinfo array.  We can do
-     this only if all modules which used this memory are unloaded.
-     Also, the first element of the list does not have to be
-     deallocated.  It was allocated in the dynamic linker (i.e., with
-     a different malloc).  */
-  if (free_slotinfo (GL(dl_tls_dtv_slotinfo_list)->next))
-    GL(dl_tls_dtv_slotinfo_list)->next = NULL;
+  if (USE___THREAD || GL(dl_tls_dtv_slotinfo_list) != NULL)
+    {
+      /* Free the memory allocated for the dtv slotinfo array.  We can do
+	 this only if all modules which used this memory are unloaded.
+	 Also, the first element of the list does not have to be
+	 deallocated.  It was allocated in the dynamic linker (i.e., with
+	 a different malloc).  */
+      if (free_slotinfo (GL(dl_tls_dtv_slotinfo_list)->next))
+	GL(dl_tls_dtv_slotinfo_list)->next = NULL;
+    }
 #endif
 }
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 3452c0b..c550204 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -942,7 +942,19 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
 
 	case PT_TLS:
 #ifdef USE_TLS
-	  if (ph->p_memsz > 0)
+	  if (ph->p_memsz == 0)
+	    /* Nothing to do for an empty segment.  */
+	    break;
+
+	  /* If not loading the initial set of shared libraries,
+	     check whether we should permit loading a TLS segment.  */
+	  if (
+# ifdef SHARED
+	      __builtin_expect (l->l_type == lt_library, 1) ||
+# endif
+	      /* If GL(dl_tls_max_dtv_idx) == 0, then rtld.c did not
+		 set up TLS data structures, so don't use them now.  */
+	      __builtin_expect (GL(dl_tls_max_dtv_idx), 1) != 0)
 	    {
 	      l->l_tls_blocksize = ph->p_memsz;
 	      l->l_tls_align = ph->p_align;
@@ -953,14 +965,20 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
 
 	      /* Assign the next available module ID.  */
 	      l->l_tls_modid = _dl_next_tls_modid ();
+	      break;
 	    }
-#else
+
+	  if (l->l_prev == NULL)
+	    /* We are loading the executable itself when the dynamic linker
+	       was executed directly.  The setup will happen later.  */
+	    break;
+#endif
+
 	  /* Uh-oh, the binary expects TLS support but we cannot
 	     provide it.  */
 	  errval = 0;
 	  errstring = N_("cannot handle TLS data");
 	  goto call_lose;
-#endif
 	  break;
 	}
 
diff --git a/elf/rtld.c b/elf/rtld.c
index 350cc70..6e20e15 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -1139,12 +1139,14 @@ of this helper program; chances are you did not intend to run this program.\n\
     /* Assign a module ID.  */
     GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid ();
 
-# ifndef SHARED
-  /* If dynamic loading of modules with TLS is impossible we do not
-     have to initialize any of the TLS functionality unless any of the
-     initial modules uses TLS.  */
+  /* We do not initialize any of the TLS functionality unless any of the
+     initial modules uses TLS.  This makes dynamic loading of modules with
+     TLS impossible, but to support it requires either eagerly doing setup
+     now or lazily doing it later.  Doing it now makes us incompatible with
+     an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
+     used.  Trying to do it lazily is too hairy to try when there could be
+     multiple threads (from a non-TLS-using libpthread).  */
   if (GL(dl_tls_max_dtv_idx) > 0)
-# endif
     {
       struct link_map *l;
       size_t nelem;
@@ -1555,9 +1557,7 @@ cannot allocate TLS data structures for initial thread");
   GL(dl_initial_searchlist) = *GL(dl_main_searchlist);
 
 #ifdef USE_TLS
-# ifndef SHARED
-  if (GL(dl_tls_max_dtv_idx) > 0)
-# endif
+  if (GL(dl_tls_max_dtv_idx) > 0 || USE___THREAD)
     {
       /* Now that we have completed relocation, the initializer data
 	 for the TLS blocks has its final values and we can copy them
diff --git a/elf/tst-tls4.c b/elf/tst-tls4.c
index f92ee53..32ec147 100644
--- a/elf/tst-tls4.c
+++ b/elf/tst-tls4.c
@@ -4,6 +4,14 @@
 
 #include <tls.h>
 
+#ifdef USE_TLS
+# include "tls-macros.h"
+
+/* This gives the executable a TLS segment so that even if the libc.so
+   it loads has none (i.e. --with-tls --without-__thread), ld.so will
+   permit loading of objects with TLS segments.  */
+COMMON_INT_DEF(loser);
+#endif
 
 #define TEST_FUNCTION do_test ()
 static int
diff --git a/elf/tst-tls5.c b/elf/tst-tls5.c
index a571d2c..c10015d 100644
--- a/elf/tst-tls5.c
+++ b/elf/tst-tls5.c
@@ -4,6 +4,15 @@
 
 #include <tls.h>
 
+#ifdef USE_TLS
+# include "tls-macros.h"
+
+/* This gives the executable a TLS segment so that even if the libc.so
+   it loads has none (i.e. --with-tls --without-__thread), ld.so will
+   permit loading of objects with TLS segments.  */
+COMMON_INT_DEF(loser);
+#endif
+
 
 #define TEST_FUNCTION do_test ()
 static int
diff --git a/elf/tst-tls6.c b/elf/tst-tls6.c
index 2c015ef..3c5c7aa 100644
--- a/elf/tst-tls6.c
+++ b/elf/tst-tls6.c
@@ -5,6 +5,15 @@
 #include <link.h>
 #include <tls.h>
 
+#ifdef USE_TLS
+# include "tls-macros.h"
+
+/* This gives the executable a TLS segment so that even if the libc.so
+   it loads has none (i.e. --with-tls --without-__thread), ld.so will
+   permit loading of objects with TLS segments.  */
+COMMON_INT_DEF(loser);
+#endif
+
 
 #define TEST_FUNCTION do_test ()
 static int
diff --git a/elf/tst-tls7.c b/elf/tst-tls7.c
index 4f785fe..77d2016 100644
--- a/elf/tst-tls7.c
+++ b/elf/tst-tls7.c
@@ -5,6 +5,15 @@
 #include <link.h>
 #include <tls.h>
 
+#ifdef USE_TLS
+# include "tls-macros.h"
+
+/* This gives the executable a TLS segment so that even if the libc.so
+   it loads has none (i.e. --with-tls --without-__thread), ld.so will
+   permit loading of objects with TLS segments.  */
+COMMON_INT_DEF(loser);
+#endif
+
 
 #define TEST_FUNCTION do_test ()
 static int
diff --git a/elf/tst-tls8.c b/elf/tst-tls8.c
index e300bc5..7444c26 100644
--- a/elf/tst-tls8.c
+++ b/elf/tst-tls8.c
@@ -5,6 +5,15 @@
 #include <link.h>
 #include <tls.h>
 
+#ifdef USE_TLS
+# include "tls-macros.h"
+
+/* This gives the executable a TLS segment so that even if the libc.so
+   it loads has none (i.e. --with-tls --without-__thread), ld.so will
+   permit loading of objects with TLS segments.  */
+COMMON_INT_DEF(loser);
+#endif
+
 
 #define TEST_FUNCTION do_test ()
 static int
diff --git a/elf/tst-tls9.c b/elf/tst-tls9.c
index cd958e4..a679efc 100644
--- a/elf/tst-tls9.c
+++ b/elf/tst-tls9.c
@@ -5,6 +5,15 @@
 #include <link.h>
 #include <tls.h>
 
+#ifdef USE_TLS
+# include "tls-macros.h"
+
+/* This gives the executable a TLS segment so that even if the libc.so
+   it loads has none (i.e. --with-tls --without-__thread), ld.so will
+   permit loading of objects with TLS segments.  */
+COMMON_INT_DEF(loser);
+#endif
+
 
 #define TEST_FUNCTION do_test ()
 static int
diff --git a/linuxthreads/sysdeps/i386/tls.h b/linuxthreads/sysdeps/i386/tls.h
index 7715303..8bbe5f2 100644
--- a/linuxthreads/sysdeps/i386/tls.h
+++ b/linuxthreads/sysdeps/i386/tls.h
@@ -43,8 +43,17 @@ typedef struct
 #endif
 
 
-/* We can support TLS only if the floating-stack support is available.  */
-#if defined FLOATING_STACKS && defined HAVE_TLS_SUPPORT
+/* We can support TLS only if the floating-stack support is available.
+   However, we want to compile in the support and test at runtime whether
+   the running kernel can support it or not.  To avoid bothering with the
+   TLS support code at all, use configure --without-tls.
+
+   We need USE_TLS to be consistently defined, for ldsodefs.h conditionals.
+   But some of the code below can cause problems in building libpthread
+   (e.g. useldt.h will defined FLOATING_STACKS when it shouldn't).  */
+
+#if defined HAVE_TLS_SUPPORT \
+    && (defined FLOATING_STACKS || !defined IS_IN_libpthread)
 
 /* Signal that TLS support is available.  */
 # define USE_TLS	1
@@ -96,8 +105,21 @@ typedef struct
 #   define TLS_LOAD_EBX
 #  endif
 
+#  if __ASSUME_LDT_WORKS > 0
+#   define TLS_DO_MODIFY_LDT_KERNEL_CHECK /* Nothing to do.  */
+#  else
+#   include "useldt.h"		/* For the structure.  */
+#   define TLS_DO_MODIFY_LDT_KERNEL_CHECK				      \
+  if (__builtin_expect (GL(dl_osversion) < 131939, 0))			      \
+    _dl_fatal_printf ("kernel %u.%u.%u cannot support thread-local storage\n",\
+		      (GL(dl_osversion) >> 16) & 0xff,			      \
+		      (GL(dl_osversion) >> 8) & 0xff,			      \
+		      (GL(dl_osversion) >> 0) & 0xff);
+#  endif
+
 #  define TLS_DO_MODIFY_LDT(descr, nr)					      \
 ({									      \
+  TLS_DO_MODIFY_LDT_KERNEL_CHECK					      \
   struct modify_ldt_ldt_s ldt_entry =					      \
     { nr, (unsigned long int) (descr), 0xfffff /* 4GB in pages */,	      \
       1, 0, 0, 1, 0, 1, 0 };						      \
@@ -177,7 +199,7 @@ typedef struct
   ({ struct _pthread_descr_struct *__descr;				      \
      THREAD_GETMEM (__descr, p_header.data.dtvp); })
 
-# endif	/* FLOATING_STACKS && HAVE_TLS_SUPPORT */
+# endif	/* HAVE_TLS_SUPPORT && (FLOATING_STACKS || !IS_IN_libpthread) */
 #endif /* __ASSEMBLER__ */
 
 #endif	/* tls.h */
diff --git a/linuxthreads/tst-context.c b/linuxthreads/tst-context.c
index 5c3272a..2938a9f 100644
--- a/linuxthreads/tst-context.c
+++ b/linuxthreads/tst-context.c
@@ -1,3 +1,12 @@
+/* Ack, a hack!  We need to get the proper definition, or lack thereof,
+   for FLOATING_STACKS.  But when !IS_IN_libpthread, this can get defined
+   incidentally by <tls.h>.  So kludge around it.  */
+
+#define IS_IN_libpthread
+#include <tls.h>
+#undef IS_IN_libpthread
+#undef USE___THREAD
+
 #include <errno.h>
 #include <error.h>
 #include <pthread.h>
@@ -5,8 +14,6 @@
 #include <stdlib.h>
 #include <ucontext.h>
 
-#include "pt-machine.h"
-
 
 #define N	4