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-rw-r--r--elf/dl-tls.c843
1 files changed, 843 insertions, 0 deletions
diff --git a/elf/dl-tls.c b/elf/dl-tls.c
new file mode 100644
index 0000000..a0f4f77
--- /dev/null
+++ b/elf/dl-tls.c
@@ -0,0 +1,843 @@
+/* Thread-local storage handling in the ELF dynamic linker. Generic version.
+ Copyright (C) 2002,2003,2004,2005,2006 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 <errno.h>
+#include <libintl.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/param.h>
+
+#include <tls.h>
+
+/* We don't need any of this if TLS is not supported. */
+#ifdef USE_TLS
+
+# include <dl-tls.h>
+# include <ldsodefs.h>
+
+/* Amount of excess space to allocate in the static TLS area
+ to allow dynamic loading of modules defining IE-model TLS data. */
+# define TLS_STATIC_SURPLUS 64 + DL_NNS * 100
+
+/* Value used for dtv entries for which the allocation is delayed. */
+# define TLS_DTV_UNALLOCATED ((void *) -1l)
+
+
+/* Out-of-memory handler. */
+# ifdef SHARED
+static void
+__attribute__ ((__noreturn__))
+oom (void)
+{
+ _dl_fatal_printf ("cannot allocate memory for thread-local data: ABORT\n");
+}
+# endif
+
+
+size_t
+internal_function
+_dl_next_tls_modid (void)
+{
+ size_t result;
+
+ if (__builtin_expect (GL(dl_tls_dtv_gaps), false))
+ {
+ size_t disp = 0;
+ struct dtv_slotinfo_list *runp = GL(dl_tls_dtv_slotinfo_list);
+
+ /* 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.
+
+ 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))
+ {
+ /* The new index must indeed be exactly one higher than the
+ previous high. */
+ assert (result == GL(dl_tls_max_dtv_idx) + 1);
+ /* There is no gap anymore. */
+ GL(dl_tls_dtv_gaps) = false;
+
+ goto nogaps;
+ }
+ }
+ else
+ {
+ /* No gaps, allocate a new entry. */
+ nogaps:
+
+ result = ++GL(dl_tls_max_dtv_idx);
+ }
+
+ return result;
+}
+
+
+# ifdef SHARED
+void
+internal_function
+_dl_determine_tlsoffset (void)
+{
+ size_t max_align = TLS_TCB_ALIGN;
+ size_t freetop = 0;
+ size_t freebottom = 0;
+
+ /* The first element of the dtv slot info list is allocated. */
+ assert (GL(dl_tls_dtv_slotinfo_list) != NULL);
+ /* There is at this point only one element in the
+ dl_tls_dtv_slotinfo_list list. */
+ assert (GL(dl_tls_dtv_slotinfo_list)->next == NULL);
+
+ struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo;
+
+ /* Determining the offset of the various parts of the static TLS
+ block has several dependencies. In addition we have to work
+ around bugs in some toolchains.
+
+ Each TLS block from the objects available at link time has a size
+ and an alignment requirement. The GNU ld computes the alignment
+ requirements for the data at the positions *in the file*, though.
+ I.e, it is not simply possible to allocate a block with the size
+ of the TLS program header entry. The data is layed out assuming
+ that the first byte of the TLS block fulfills
+
+ p_vaddr mod p_align == &TLS_BLOCK mod p_align
+
+ This means we have to add artificial padding at the beginning of
+ the TLS block. These bytes are never used for the TLS data in
+ this module but the first byte allocated must be aligned
+ according to mod p_align == 0 so that the first byte of the TLS
+ block is aligned according to p_vaddr mod p_align. This is ugly
+ and the linker can help by computing the offsets in the TLS block
+ assuming the first byte of the TLS block is aligned according to
+ p_align.
+
+ The extra space which might be allocated before the first byte of
+ the TLS block need not go unused. The code below tries to use
+ that memory for the next TLS block. This can work if the total
+ memory requirement for the next TLS block is smaller than the
+ gap. */
+
+# if TLS_TCB_AT_TP
+ /* We simply start with zero. */
+ size_t offset = 0;
+
+ for (size_t cnt = 0; slotinfo[cnt].map != NULL; ++cnt)
+ {
+ assert (cnt < GL(dl_tls_dtv_slotinfo_list)->len);
+
+ size_t firstbyte = (-slotinfo[cnt].map->l_tls_firstbyte_offset
+ & (slotinfo[cnt].map->l_tls_align - 1));
+ size_t off;
+ max_align = MAX (max_align, slotinfo[cnt].map->l_tls_align);
+
+ if (freebottom - freetop >= slotinfo[cnt].map->l_tls_blocksize)
+ {
+ off = roundup (freetop + slotinfo[cnt].map->l_tls_blocksize
+ - firstbyte, slotinfo[cnt].map->l_tls_align)
+ + firstbyte;
+ if (off <= freebottom)
+ {
+ freetop = off;
+
+ /* XXX For some architectures we perhaps should store the
+ negative offset. */
+ slotinfo[cnt].map->l_tls_offset = off;
+ continue;
+ }
+ }
+
+ off = roundup (offset + slotinfo[cnt].map->l_tls_blocksize - firstbyte,
+ slotinfo[cnt].map->l_tls_align) + firstbyte;
+ if (off > offset + slotinfo[cnt].map->l_tls_blocksize
+ + (freebottom - freetop))
+ {
+ freetop = offset;
+ freebottom = off - slotinfo[cnt].map->l_tls_blocksize;
+ }
+ offset = off;
+
+ /* XXX For some architectures we perhaps should store the
+ negative offset. */
+ slotinfo[cnt].map->l_tls_offset = off;
+ }
+
+ GL(dl_tls_static_used) = offset;
+ GL(dl_tls_static_size) = (roundup (offset + TLS_STATIC_SURPLUS, max_align)
+ + TLS_TCB_SIZE);
+# elif TLS_DTV_AT_TP
+ /* The TLS blocks start right after the TCB. */
+ size_t offset = TLS_TCB_SIZE;
+
+ for (size_t cnt = 0; slotinfo[cnt].map != NULL; ++cnt)
+ {
+ assert (cnt < GL(dl_tls_dtv_slotinfo_list)->len);
+
+ size_t firstbyte = (-slotinfo[cnt].map->l_tls_firstbyte_offset
+ & (slotinfo[cnt].map->l_tls_align - 1));
+ size_t off;
+ max_align = MAX (max_align, slotinfo[cnt].map->l_tls_align);
+
+ if (slotinfo[cnt].map->l_tls_blocksize <= freetop - freebottom)
+ {
+ off = roundup (freebottom, slotinfo[cnt].map->l_tls_align);
+ if (off - freebottom < firstbyte)
+ off += slotinfo[cnt].map->l_tls_align;
+ if (off + slotinfo[cnt].map->l_tls_blocksize - firstbyte <= freetop)
+ {
+ slotinfo[cnt].map->l_tls_offset = off - firstbyte;
+ freebottom = (off + slotinfo[cnt].map->l_tls_blocksize
+ - firstbyte);
+ continue;
+ }
+ }
+
+ off = roundup (offset, slotinfo[cnt].map->l_tls_align);
+ if (off - offset < firstbyte)
+ off += slotinfo[cnt].map->l_tls_align;
+
+ slotinfo[cnt].map->l_tls_offset = off - firstbyte;
+ if (off - firstbyte - offset > freetop - freebottom)
+ {
+ freebottom = offset;
+ freetop = off - firstbyte;
+ }
+
+ offset = off + slotinfo[cnt].map->l_tls_blocksize - firstbyte;
+ }
+
+ GL(dl_tls_static_used) = offset;
+ GL(dl_tls_static_size) = roundup (offset + TLS_STATIC_SURPLUS,
+ TLS_TCB_ALIGN);
+# else
+# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+# endif
+
+ /* The alignment requirement for the static TLS block. */
+ GL(dl_tls_static_align) = max_align;
+}
+
+
+/* This is called only when the data structure setup was skipped at startup,
+ when there was no need for it then. Now we have dynamically loaded
+ something needing TLS, or libpthread needs it. */
+int
+internal_function
+_dl_tls_setup (void)
+{
+ assert (GL(dl_tls_dtv_slotinfo_list) == NULL);
+ assert (GL(dl_tls_max_dtv_idx) == 0);
+
+ const size_t nelem = 2 + TLS_SLOTINFO_SURPLUS;
+
+ GL(dl_tls_dtv_slotinfo_list)
+ = calloc (1, (sizeof (struct dtv_slotinfo_list)
+ + nelem * sizeof (struct dtv_slotinfo)));
+ if (GL(dl_tls_dtv_slotinfo_list) == NULL)
+ return -1;
+
+ GL(dl_tls_dtv_slotinfo_list)->len = nelem;
+
+ /* Number of elements in the static TLS block. It can't be zero
+ because of various assumptions. The one element is null. */
+ GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx) = 1;
+
+ /* This initializes more variables for us. */
+ _dl_determine_tlsoffset ();
+
+ return 0;
+}
+rtld_hidden_def (_dl_tls_setup)
+# endif
+
+static void *
+internal_function
+allocate_dtv (void *result)
+{
+ dtv_t *dtv;
+ size_t dtv_length;
+
+ /* We allocate a few more elements in the dtv than are needed for the
+ initial set of modules. This should avoid in most cases expansions
+ of the dtv. */
+ dtv_length = GL(dl_tls_max_dtv_idx) + DTV_SURPLUS;
+ dtv = calloc (dtv_length + 2, sizeof (dtv_t));
+ if (dtv != NULL)
+ {
+ /* This is the initial length of the dtv. */
+ dtv[0].counter = dtv_length;
+
+ /* The rest of the dtv (including the generation counter) is
+ Initialize with zero to indicate nothing there. */
+
+ /* Add the dtv to the thread data structures. */
+ INSTALL_DTV (result, dtv);
+ }
+ else
+ result = NULL;
+
+ return result;
+}
+
+
+/* Get size and alignment requirements of the static TLS block. */
+void
+internal_function
+_dl_get_tls_static_info (size_t *sizep, size_t *alignp)
+{
+ *sizep = GL(dl_tls_static_size);
+ *alignp = GL(dl_tls_static_align);
+}
+
+
+void *
+internal_function
+_dl_allocate_tls_storage (void)
+{
+ void *result;
+ size_t size = GL(dl_tls_static_size);
+
+# if TLS_DTV_AT_TP
+ /* Memory layout is:
+ [ TLS_PRE_TCB_SIZE ] [ TLS_TCB_SIZE ] [ TLS blocks ]
+ ^ This should be returned. */
+ size += (TLS_PRE_TCB_SIZE + GL(dl_tls_static_align) - 1)
+ & ~(GL(dl_tls_static_align) - 1);
+# endif
+
+ /* Allocate a correctly aligned chunk of memory. */
+ result = __libc_memalign (GL(dl_tls_static_align), size);
+ if (__builtin_expect (result != NULL, 1))
+ {
+ /* Allocate the DTV. */
+ void *allocated = result;
+
+# if TLS_TCB_AT_TP
+ /* The TCB follows the TLS blocks. */
+ result = (char *) result + size - TLS_TCB_SIZE;
+
+ /* Clear the TCB data structure. We can't ask the caller (i.e.
+ libpthread) to do it, because we will initialize the DTV et al. */
+ memset (result, '\0', TLS_TCB_SIZE);
+# elif TLS_DTV_AT_TP
+ result = (char *) result + size - GL(dl_tls_static_size);
+
+ /* Clear the TCB data structure and TLS_PRE_TCB_SIZE bytes before it.
+ We can't ask the caller (i.e. libpthread) to do it, because we will
+ initialize the DTV et al. */
+ memset ((char *) result - TLS_PRE_TCB_SIZE, '\0',
+ TLS_PRE_TCB_SIZE + TLS_TCB_SIZE);
+# endif
+
+ result = allocate_dtv (result);
+ if (result == NULL)
+ free (allocated);
+ }
+
+ return result;
+}
+
+
+void *
+internal_function
+_dl_allocate_tls_init (void *result)
+{
+ if (result == NULL)
+ /* The memory allocation failed. */
+ return NULL;
+
+ dtv_t *dtv = GET_DTV (result);
+ struct dtv_slotinfo_list *listp;
+ size_t total = 0;
+ size_t maxgen = 0;
+
+ /* We have to prepare the dtv for all currently loaded modules using
+ TLS. For those which are dynamically loaded we add the values
+ indicating deferred allocation. */
+ listp = GL(dl_tls_dtv_slotinfo_list);
+ while (1)
+ {
+ size_t cnt;
+
+ for (cnt = total == 0 ? 1 : 0; cnt < listp->len; ++cnt)
+ {
+ struct link_map *map;
+ void *dest;
+
+ /* Check for the total number of used slots. */
+ if (total + cnt > GL(dl_tls_max_dtv_idx))
+ break;
+
+ map = listp->slotinfo[cnt].map;
+ if (map == NULL)
+ /* Unused entry. */
+ continue;
+
+ /* Keep track of the maximum generation number. This might
+ not be the generation counter. */
+ maxgen = MAX (maxgen, listp->slotinfo[cnt].gen);
+
+ if (map->l_tls_offset == NO_TLS_OFFSET)
+ {
+ /* For dynamically loaded modules we simply store
+ the value indicating deferred allocation. */
+ dtv[map->l_tls_modid].pointer.val = TLS_DTV_UNALLOCATED;
+ dtv[map->l_tls_modid].pointer.is_static = false;
+ continue;
+ }
+
+ assert (map->l_tls_modid == cnt);
+ assert (map->l_tls_blocksize >= map->l_tls_initimage_size);
+# if TLS_TCB_AT_TP
+ assert ((size_t) map->l_tls_offset >= map->l_tls_blocksize);
+ dest = (char *) result - map->l_tls_offset;
+# elif TLS_DTV_AT_TP
+ dest = (char *) result + map->l_tls_offset;
+# else
+# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+# endif
+
+ /* Copy the initialization image and clear the BSS part. */
+ dtv[map->l_tls_modid].pointer.val = dest;
+ dtv[map->l_tls_modid].pointer.is_static = true;
+ memset (__mempcpy (dest, map->l_tls_initimage,
+ map->l_tls_initimage_size), '\0',
+ map->l_tls_blocksize - map->l_tls_initimage_size);
+ }
+
+ total += cnt;
+ if (total >= GL(dl_tls_max_dtv_idx))
+ break;
+
+ listp = listp->next;
+ assert (listp != NULL);
+ }
+
+ /* The DTV version is up-to-date now. */
+ dtv[0].counter = maxgen;
+
+ return result;
+}
+rtld_hidden_def (_dl_allocate_tls_init)
+
+void *
+internal_function
+_dl_allocate_tls (void *mem)
+{
+ return _dl_allocate_tls_init (mem == NULL
+ ? _dl_allocate_tls_storage ()
+ : allocate_dtv (mem));
+}
+rtld_hidden_def (_dl_allocate_tls)
+
+
+void
+internal_function
+_dl_deallocate_tls (void *tcb, bool dealloc_tcb)
+{
+ dtv_t *dtv = GET_DTV (tcb);
+
+ /* We need to free the memory allocated for non-static TLS. */
+ for (size_t cnt = 0; cnt < dtv[-1].counter; ++cnt)
+ if (! dtv[1 + cnt].pointer.is_static
+ && dtv[1 + cnt].pointer.val != TLS_DTV_UNALLOCATED)
+ free (dtv[1 + cnt].pointer.val);
+
+ /* The array starts with dtv[-1]. */
+#ifdef SHARED
+ if (dtv != GL(dl_initial_dtv))
+#endif
+ free (dtv - 1);
+
+ if (dealloc_tcb)
+ {
+# if TLS_TCB_AT_TP
+ /* The TCB follows the TLS blocks. Back up to free the whole block. */
+ tcb -= GL(dl_tls_static_size) - TLS_TCB_SIZE;
+# elif TLS_DTV_AT_TP
+ /* Back up the TLS_PRE_TCB_SIZE bytes. */
+ tcb -= (TLS_PRE_TCB_SIZE + GL(dl_tls_static_align) - 1)
+ & ~(GL(dl_tls_static_align) - 1);
+# endif
+ free (tcb);
+ }
+}
+rtld_hidden_def (_dl_deallocate_tls)
+
+
+# ifdef SHARED
+/* 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 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
+
+
+static void *
+allocate_and_init (struct link_map *map)
+{
+ void *newp;
+
+ newp = __libc_memalign (map->l_tls_align, map->l_tls_blocksize);
+ if (newp == NULL)
+ oom ();
+
+ /* Initialize the memory. */
+ memset (__mempcpy (newp, map->l_tls_initimage, map->l_tls_initimage_size),
+ '\0', map->l_tls_blocksize - map->l_tls_initimage_size);
+
+ return newp;
+}
+
+
+struct link_map *
+_dl_update_slotinfo (unsigned long int req_modid)
+{
+ struct link_map *the_map = NULL;
+ dtv_t *dtv = THREAD_DTV ();
+
+ /* The global dl_tls_dtv_slotinfo array contains for each module
+ index the generation counter current when the entry was created.
+ This array never shrinks so that all module indices which were
+ valid at some time can be used to access it. Before the first
+ use of a new module index in this function the array was extended
+ appropriately. Access also does not have to be guarded against
+ modifications of the array. It is assumed that pointer-size
+ values can be read atomically even in SMP environments. It is
+ possible that other threads at the same time dynamically load
+ code and therefore add to the slotinfo list. This is a problem
+ since we must not pick up any information about incomplete work.
+ The solution to this is to ignore all dtv slots which were
+ created after the one we are currently interested. We know that
+ dynamic loading for this module is completed and this is the last
+ load operation we know finished. */
+ unsigned long int idx = req_modid;
+ struct dtv_slotinfo_list *listp = GL(dl_tls_dtv_slotinfo_list);
+
+ while (idx >= listp->len)
+ {
+ idx -= listp->len;
+ listp = listp->next;
+ }
+
+ if (dtv[0].counter < listp->slotinfo[idx].gen)
+ {
+ /* The generation counter for the slot is higher than what the
+ current dtv implements. We have to update the whole dtv but
+ only those entries with a generation counter <= the one for
+ the entry we need. */
+ size_t new_gen = listp->slotinfo[idx].gen;
+ size_t total = 0;
+
+ /* We have to look through the entire dtv slotinfo list. */
+ listp = GL(dl_tls_dtv_slotinfo_list);
+ do
+ {
+ for (size_t cnt = total == 0 ? 1 : 0; cnt < listp->len; ++cnt)
+ {
+ size_t gen = listp->slotinfo[cnt].gen;
+
+ if (gen > new_gen)
+ /* This is a slot for a generation younger than the
+ one we are handling now. It might be incompletely
+ set up so ignore it. */
+ continue;
+
+ /* If the entry is older than the current dtv layout we
+ know we don't have to handle it. */
+ if (gen <= dtv[0].counter)
+ continue;
+
+ /* If there is no map this means the entry is empty. */
+ struct link_map *map = listp->slotinfo[cnt].map;
+ if (map == NULL)
+ {
+ /* If this modid was used at some point the memory
+ might still be allocated. */
+ if (! dtv[total + cnt].pointer.is_static
+ && dtv[total + cnt].pointer.val != TLS_DTV_UNALLOCATED)
+ {
+ free (dtv[total + cnt].pointer.val);
+ dtv[total + cnt].pointer.val = TLS_DTV_UNALLOCATED;
+ }
+
+ continue;
+ }
+
+ /* Check whether the current dtv array is large enough. */
+ size_t modid = map->l_tls_modid;
+ assert (total + cnt == modid);
+ if (dtv[-1].counter < modid)
+ {
+ /* Reallocate the dtv. */
+ dtv_t *newp;
+ size_t newsize = GL(dl_tls_max_dtv_idx) + DTV_SURPLUS;
+ size_t oldsize = dtv[-1].counter;
+
+ assert (map->l_tls_modid <= newsize);
+
+ if (dtv == GL(dl_initial_dtv))
+ {
+ /* This is the initial dtv that was allocated
+ during rtld startup using the dl-minimal.c
+ malloc instead of the real malloc. We can't
+ free it, we have to abandon the old storage. */
+
+ newp = malloc ((2 + newsize) * sizeof (dtv_t));
+ if (newp == NULL)
+ oom ();
+ memcpy (newp, &dtv[-1], oldsize * sizeof (dtv_t));
+ }
+ else
+ {
+ newp = realloc (&dtv[-1],
+ (2 + newsize) * sizeof (dtv_t));
+ if (newp == NULL)
+ oom ();
+ }
+
+ newp[0].counter = newsize;
+
+ /* Clear the newly allocated part. */
+ memset (newp + 2 + oldsize, '\0',
+ (newsize - oldsize) * sizeof (dtv_t));
+
+ /* Point dtv to the generation counter. */
+ dtv = &newp[1];
+
+ /* Install this new dtv in the thread data
+ structures. */
+ INSTALL_NEW_DTV (dtv);
+ }
+
+ /* If there is currently memory allocate for this
+ dtv entry free it. */
+ /* XXX Ideally we will at some point create a memory
+ pool. */
+ if (! dtv[modid].pointer.is_static
+ && dtv[modid].pointer.val != TLS_DTV_UNALLOCATED)
+ /* Note that free is called for NULL is well. We
+ deallocate even if it is this dtv entry we are
+ supposed to load. The reason is that we call
+ memalign and not malloc. */
+ 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;
+
+ if (modid == req_modid)
+ the_map = map;
+ }
+
+ total += listp->len;
+ }
+ while ((listp = listp->next) != NULL);
+
+ /* This will be the new maximum generation counter. */
+ dtv[0].counter = new_gen;
+ }
+
+ return the_map;
+}
+
+
+/* The generic dynamic and local dynamic model cannot be used in
+ statically linked applications. */
+void *
+__tls_get_addr (GET_ADDR_ARGS)
+{
+ dtv_t *dtv = THREAD_DTV ();
+ struct link_map *the_map = NULL;
+ void *p;
+
+ if (__builtin_expect (dtv[0].counter != GL(dl_tls_generation), 0))
+ the_map = _dl_update_slotinfo (GET_ADDR_MODULE);
+
+ p = dtv[GET_ADDR_MODULE].pointer.val;
+
+ if (__builtin_expect (p == TLS_DTV_UNALLOCATED, 0))
+ {
+ /* The allocation was deferred. Do it now. */
+ if (the_map == NULL)
+ {
+ /* Find the link map for this module. */
+ size_t idx = GET_ADDR_MODULE;
+ struct dtv_slotinfo_list *listp = GL(dl_tls_dtv_slotinfo_list);
+
+ while (idx >= listp->len)
+ {
+ idx -= listp->len;
+ listp = listp->next;
+ }
+
+ the_map = listp->slotinfo[idx].map;
+ }
+
+ p = dtv[GET_ADDR_MODULE].pointer.val = allocate_and_init (the_map);
+ dtv[GET_ADDR_MODULE].pointer.is_static = false;
+ }
+
+ return (char *) p + GET_ADDR_OFFSET;
+}
+# endif
+
+
+/* Look up the module's TLS block as for __tls_get_addr,
+ but never touch anything. Return null if it's not allocated yet. */
+void *
+internal_function
+_dl_tls_get_addr_soft (struct link_map *l)
+{
+ if (__builtin_expect (l->l_tls_modid == 0, 0))
+ /* This module has no TLS segment. */
+ return NULL;
+
+ dtv_t *dtv = THREAD_DTV ();
+ if (__builtin_expect (dtv[0].counter != GL(dl_tls_generation), 0))
+ {
+ /* This thread's DTV is not completely current,
+ but it might already cover this module. */
+
+ if (l->l_tls_modid >= dtv[-1].counter)
+ /* Nope. */
+ return NULL;
+
+ size_t idx = l->l_tls_modid;
+ struct dtv_slotinfo_list *listp = GL(dl_tls_dtv_slotinfo_list);
+ while (idx >= listp->len)
+ {
+ idx -= listp->len;
+ listp = listp->next;
+ }
+
+ /* We've reached the slot for this module.
+ If its generation counter is higher than the DTV's,
+ this thread does not know about this module yet. */
+ if (dtv[0].counter < listp->slotinfo[idx].gen)
+ return NULL;
+ }
+
+ void *data = dtv[l->l_tls_modid].pointer.val;
+ if (__builtin_expect (data == TLS_DTV_UNALLOCATED, 0))
+ /* The DTV is current, but this thread has not yet needed
+ to allocate this module's segment. */
+ data = NULL;
+
+ return data;
+}
+
+
+void
+_dl_add_to_slotinfo (struct link_map *l)
+{
+ /* Now that we know the object is loaded successfully add
+ modules containing TLS data to the dtv info table. We
+ might have to increase its size. */
+ struct dtv_slotinfo_list *listp;
+ struct dtv_slotinfo_list *prevp;
+ size_t idx = l->l_tls_modid;
+
+ /* Find the place in the dtv slotinfo list. */
+ listp = GL(dl_tls_dtv_slotinfo_list);
+ prevp = NULL; /* Needed to shut up gcc. */
+ do
+ {
+ /* Does it fit in the array of this list element? */
+ if (idx < listp->len)
+ break;
+ idx -= listp->len;
+ prevp = listp;
+ listp = listp->next;
+ }
+ while (listp != NULL);
+
+ if (listp == NULL)
+ {
+ /* When we come here it means we have to add a new element
+ to the slotinfo list. And the new module must be in
+ the first slot. */
+ assert (idx == 0);
+
+ listp = prevp->next = (struct dtv_slotinfo_list *)
+ malloc (sizeof (struct dtv_slotinfo_list)
+ + TLS_SLOTINFO_SURPLUS * sizeof (struct dtv_slotinfo));
+ if (listp == NULL)
+ {
+ /* We ran out of memory. We will simply fail this
+ call but don't undo anything we did so far. The
+ application will crash or be terminated anyway very
+ soon. */
+
+ /* We have to do this since some entries in the dtv
+ slotinfo array might already point to this
+ generation. */
+ ++GL(dl_tls_generation);
+
+ _dl_signal_error (ENOMEM, "dlopen", NULL, N_("\
+cannot create TLS data structures"));
+ }
+
+ listp->len = TLS_SLOTINFO_SURPLUS;
+ listp->next = NULL;
+ memset (listp->slotinfo, '\0',
+ TLS_SLOTINFO_SURPLUS * sizeof (struct dtv_slotinfo));
+ }
+
+ /* Add the information into the slotinfo data structure. */
+ listp->slotinfo[idx].map = l;
+ listp->slotinfo[idx].gen = GL(dl_tls_generation) + 1;
+}
+#endif /* use TLS */