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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 */