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authorJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
committerJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
commit0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (patch)
tree2ea1f8305970753e4a657acb2ccc15ca3eec8e2c /sysdeps/generic/dl-tls.c
parent7d58530341304d403a6626d7f7a1913165fe2f32 (diff)
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2.5-18.1
Diffstat (limited to 'sysdeps/generic/dl-tls.c')
-rw-r--r--sysdeps/generic/dl-tls.c713
1 files changed, 0 insertions, 713 deletions
diff --git a/sysdeps/generic/dl-tls.c b/sysdeps/generic/dl-tls.c
deleted file mode 100644
index 3382e3493c..0000000000
--- a/sysdeps/generic/dl-tls.c
+++ /dev/null
@@ -1,713 +0,0 @@
-/* Thread-local storage handling in the ELF dynamic linker. Generic version.
- Copyright (C) 2002, 2003, 2004 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 <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. */
- 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);
- }
-
- 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));
-
- /* 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)
-{
- struct dtv_slotinfo *slotinfo;
- size_t max_align = TLS_TCB_ALIGN;
- size_t offset, freetop = 0, freebottom = 0;
- size_t cnt;
-
- /* 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);
-
- 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. */
- offset = 0;
-
- for (cnt = 1; 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. */
- offset = TLS_TCB_SIZE;
-
- for (cnt = 1; 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;
-
- /* We have to look 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;
-
- 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 = TLS_DTV_UNALLOCATED;
- 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 = dest;
- 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);
- }
-
- 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);
-
- /* 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;
-}
-
-
-/* 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))
- {
- struct dtv_slotinfo_list *listp;
- size_t idx;
-
- /* 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. */
- idx = GET_ADDR_MODULE;
- 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
- {
- size_t cnt;
-
- for (cnt = total = 0 ? 1 : 0; cnt < listp->len; ++cnt)
- {
- size_t gen = listp->slotinfo[cnt].gen;
- struct link_map *map;
- size_t modid;
-
- 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. */
- 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 != TLS_DTV_UNALLOCATED)
- {
- free (dtv[total + cnt].pointer);
- dtv[total + cnt].pointer = TLS_DTV_UNALLOCATED;
- }
-
- continue;
- }
-
- /* Check whether the current dtv array is large enough. */
- 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 != 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);
-
- /* This module is loaded dynamically- We defer
- memory allocation. */
- dtv[modid].pointer = TLS_DTV_UNALLOCATED;
-
- if (modid == GET_ADDR_MODULE)
- the_map = map;
- }
-
- total += listp->len;
- }
- while ((listp = listp->next) != NULL);
-
- /* This will be the new maximum generation counter. */
- dtv[0].counter = new_gen;
- }
- }
-
- p = dtv[GET_ADDR_MODULE].pointer;
-
- 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 = allocate_and_init (the_map);
- }
-
- return (char *) p + GET_ADDR_OFFSET;
-}
-# endif
-
-#endif /* use TLS */