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authorUlrich Drepper <drepper@redhat.com>2002-02-07 04:08:19 +0000
committerUlrich Drepper <drepper@redhat.com>2002-02-07 04:08:19 +0000
commit3fb558781fe9bdad55c25157eaea0531e727ba39 (patch)
treee60fe01b6a6ee1826e05e50924e5b6a4bcf253b2 /sysdeps/generic/dl-tls.c
parenta53a253b90b2cd722ac6718464931cf920b56cf4 (diff)
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Update.
2002-02-06  Ulrich Drepper  <drepper@redhat.com>

	* Versions.def [ld]: Add GLIBC_2.3.
	* elf/Versions [ld]: Add __tls_get_addr to GLIBC_2.3.
	* elf/Makefile (dl-routines): Add dl-tls.
	(distribute): Add dl-tls.h.
	* sysdeps/generic/ldsodefs.h (struct rtld_global): Remove
	_dl_tls_module_cnt, add _dl_tls_max_dtv_idx and _dl_tls_dtv_gaps.
	Add prototypes for _dl_next_tls_modid and _dl_determine_tlsoffset.
	* elf/dl-load.c (_dl_map_object_from_fd): Store alignment requirement
	along with the other info in the link map.  Change queueing of init
	images for double linked list.  Use _dl_next_tls_modid to compute
	l_tls_modid.
	* elf/rtld.c (_dl_start_final): Store alignment requirement
	along with the other info in rtld map and executable map.
	(dl_main): Add ld.so to the init image list if necessary.  Compute
	final module ID with _dl_next_tls_modid.
	* include/link.h (struct link_map): Add l_tls_previmage and
	l_tls_align.
	* eld/dl-support.c: Define _dl_tls_max_dtv_idx and _dl_tls_dtv_gaps.
	* sysdeps/i386/elf/Versions: New file.
	* sysdeps/generic/dl-tls.c: New file.
	* sysdeps/generic/dl-tls.h: New file.
	* sysdeps/i386/dl-tls.h: New file.

	attribute((packed)) to counter stupid people misusing gcc options.
Diffstat (limited to 'sysdeps/generic/dl-tls.c')
-rw-r--r--sysdeps/generic/dl-tls.c155
1 files changed, 155 insertions, 0 deletions
diff --git a/sysdeps/generic/dl-tls.c b/sysdeps/generic/dl-tls.c
new file mode 100644
index 0000000000..557a023453
--- /dev/null
+++ b/sysdeps/generic/dl-tls.c
@@ -0,0 +1,155 @@
+/* Thread-local storage handling in the ELF dynamic linker.  Generic version.
+   Copyright (C) 2002 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <assert.h>
+
+#include <dl-tls.h>
+#include <ldsodefs.h>
+
+
+/* We don't need any of this if TLS is not supported.  */
+#ifdef USE_TLS
+
+/* Value used for dtv entries for which the allocation is delayed.  */
+# define TLS_DTV_UNALLOCATE	((void *) -1l)
+
+
+size_t
+internal_function
+_dl_next_tls_modid (void)
+{
+  size_t result;
+
+  if (__builtin_expect (GL(dl_tls_dtv_gaps), false))
+    {
+      /* XXX If this method proves too costly we can optimize
+	 it to use a constant time method.  But I don't think
+	 it's a problem.  */
+      struct link_map *runp = GL(dl_initimage_list);
+      bool used[GL(dl_tls_max_dtv_idx)];
+
+      assert (runp != NULL);
+      do
+	{
+	  assert (runp->l_tls_modid > 0
+		  && runp->l_tls_modid <= GL(dl_tls_max_dtv_idx));
+	  used[runp->l_tls_modid - 1] = true;
+	}
+      while ((runp = runp->l_tls_nextimage) != GL(dl_initimage_list));
+
+      result = 0;
+      do
+	/* The information about the gaps is pessimistic.  It might be
+	   there are actually none.  */
+	if (result >= GL(dl_tls_max_dtv_idx))
+	  {
+	    /* Now we know there is actually no gap.  Bump the maximum
+	       ID number and remember that there are no gaps.  */
+	    result = ++GL(dl_tls_max_dtv_idx);
+	    GL(dl_tls_dtv_gaps) = false;
+	    break;
+	  }
+      while (used[result++]);
+    }
+  else
+    /* No gaps, allocate a new entry.  */
+    result = ++GL(dl_tls_max_dtv_idx);
+
+  return result;
+}
+
+
+void
+internal_function
+_dl_determine_tlsoffset (struct link_map *firstp)
+{
+  struct link_map *runp = firstp;
+  size_t max_align = 0;
+  size_t offset;
+
+# if TLS_TCB_AT_TP
+  /* We simply start with zero.  */
+  offset = 0;
+
+  do
+    {
+      max_align = MAX (max_align, runp->l_tls_align);
+
+      /* Compute the offset of the next TLS block.  */
+      offset = roundup (offset + runp->l_tls_blocksize, runp->l_tls_align);
+
+      /* XXX For some architectures we perhaps should store the
+	 negative offset.  */
+      runp->l_tls_offset = offset;
+    }
+  while ((runp = runp->l_tls_nextimage) != firstp);
+# elif TLS_DTV_AT_TP
+  struct link_map *lastp;
+
+  /* The first block starts right after the TCB.  */
+  offset = TLS_TCB_SIZE;
+  max_align = runp->l_tls_align;
+  runp->l_tls_offset = offset;
+  lastp = runp;
+
+  while ((runp = runp->l_tls_nextimage) != firstp)
+    {
+      max_align = MAX (max_align, runp->l_tls_align);
+
+      /* Compute the offset of the next TLS block.  */
+      offset = roundup (offset + lastp->l_tls_blocksize, runp->l_tls_align);
+
+      runp->l_tls_offset = offset;
+    }
+# else
+#  error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+# endif
+}
+
+
+/* The __tls_get_addr function has two basic forms which differ in the
+   arguments.  The IA-64 form takes two parameters, the module ID and
+   offset.  The form used, among others, on IA-32 takes a reference to
+   a special structure which contain the same information.  The second
+   form seems to be more often used (in the moment) so we default to
+   it.  Users of the IA-64 form have to provide adequate definitions
+   of the following macros.  */
+# ifndef GET_ADDR_ARGS
+#  define GET_ADDR_ARGS struct tls_index *ti
+# endif
+# ifndef GET_ADDR_MODULE
+#  define GET_ADDR_MODULE ti->ti_module
+# endif
+# ifndef GET_ADDR_OFFSET
+#  define GET_ADDR_OFFSET ti->ti_offset
+# endif
+
+
+void *
+__tls_get_addr (GET_ADDR_ARGS)
+{
+  dtv_t *dtv = THREAD_DTV ();
+
+  if (dtv[GET_ADDR_MODULE].pointer == TLS_DTV_UNALLOCATE)
+    /* XXX */;
+
+  return (char *) dtv[GET_ADDR_MODULE].pointer + GET_ADDR_OFFSET;
+}
+
+#endif	/* use TLS */