diff options
Diffstat (limited to 'sysdeps/generic/dl-tls.c')
| -rw-r--r-- | sysdeps/generic/dl-tls.c | 713 |
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 */ |