/* Initialization code for TLS in statically linked application. 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 #include #include #include #ifdef SHARED #error makefile bug, this file is for static only #endif #ifdef USE_TLS extern ElfW(Phdr) *_dl_phdr; extern size_t _dl_phnum; /* DTV with just one element plus overhead. */ static dtv_t static_dtv[3]; static struct { struct dtv_slotinfo_list si; /* The dtv_slotinfo_list data structure does not include the actual informatin since it is defined as an array of size zero. We define here the necessary entries. Not that it is not important whether there is padding or not since we will always access the informatin through the 'si' element. */ struct dtv_slotinfo info[2 + TLS_SLOTINFO_SURPLUS]; } static_slotinfo; /* Fake link map for the application. */ static struct link_map static_map; /* Highest dtv index currently needed. */ size_t _dl_tls_max_dtv_idx; /* Flag signalling whether there are gaps in the module ID allocation. */ bool _dl_tls_dtv_gaps; /* Information about the dtv slots. */ struct dtv_slotinfo_list *_dl_tls_dtv_slotinfo_list; /* Number of modules in the static TLS block. */ size_t _dl_tls_static_nelem; /* Size of the static TLS block. */ size_t _dl_tls_static_size; /* Alignment requirement of the static TLS block. */ size_t _dl_tls_static_align; /* Generation counter for the dtv. */ size_t _dl_tls_generation; /* Additional definitions needed by TLS initialization. */ #ifdef TLS_INIT_HELPER TLS_INIT_HELPER #endif void __libc_setup_tls (size_t tcbsize, size_t tcbalign) { void *tlsblock; size_t memsz = 0; size_t filesz = 0; void *initimage = NULL; size_t align = 0; size_t max_align = tcbalign; size_t tcb_offset; ElfW(Phdr) *phdr; /* Look through the TLS segment if there is any. */ if (_dl_phdr != NULL) for (phdr = _dl_phdr; phdr < &_dl_phdr[_dl_phnum]; ++phdr) if (phdr->p_type == PT_TLS) { /* Remember the values we need. */ memsz = phdr->p_memsz; filesz = phdr->p_filesz; initimage = (void *) phdr->p_vaddr; align = phdr->p_align; if (phdr->p_align > max_align) max_align = phdr->p_align; break; } if (memsz == 0 && tcbsize == 0) /* We do not need a TLS block and no thread descriptor. */ return; /* We have to set up the TCB block which also (possibly) contains 'errno'. Therefore we avoid 'malloc' which might touch 'errno'. Instead we use 'sbrk' which would only uses 'errno' if it fails. In this case we are right away out of memory and the user gets what she/he deserves. */ # if TLS_TCB_AT_TP tlsblock = __sbrk (roundup (memsz, tcbalign) + tcbsize + max_align); # elif TLS_DTV_AT_TP tlsblock = __sbrk (roundup (tcbsize, align) + memsz + max_align); # else /* In case a model with a different layout for the TCB and DTV is defined add another #elif here and in the following #ifs. */ # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" # endif /* Align the TLS block. */ tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1) & ~(max_align - 1)); /* Initialize the dtv. [0] is the length, [1] the generation counter. */ static_dtv[0].counter = 1; // static_dtv[1].counter = 0; would be needed if not already done /* Initialize the TLS block. */ # if TLS_TCB_AT_TP static_dtv[2].pointer = tlsblock; # elif TLS_DTV_AT_TP tcb_offset = roundup (tcbsize, align); static_dtv[2].pointer = (char *) tlsblock + tcb_offset; # else # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" # endif memset (__mempcpy (static_dtv[2].pointer, initimage, filesz), '\0', memsz - filesz); /* Install the pointer to the dtv. */ /* Initialize the thread pointer. */ # if TLS_TCB_AT_TP tcb_offset = roundup (memsz, tcbalign); INSTALL_DTV ((char *) tlsblock + tcb_offset, static_dtv); TLS_INIT_TP ((char *) tlsblock + tcb_offset, 0); # elif TLS_DTV_AT_TP INSTALL_DTV (tlsblock, static_dtv); TLS_INIT_TP (tlsblock, 0); # else # error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined" # endif /* We have to create a fake link map which normally would be created by the dynamic linker. It just has to have enough information to make the TLS routines happy. */ static_map.l_tls_align = align; static_map.l_tls_blocksize = memsz; static_map.l_tls_initimage_size = filesz; static_map.l_tls_offset = tcb_offset; static_map.l_type = lt_executable; static_map.l_tls_modid = 1; /* Create the slotinfo list. */ static_slotinfo.si.len = 1; /* Only one element. */ // static_slotinfo.si.next = NULL; already zero static_slotinfo.si.slotinfo[1].gen = 0; static_slotinfo.si.slotinfo[1].map = &static_map; /* The slotinfo list. Will be extended by the code doing dynamic linking. */ GL(dl_tls_max_dtv_idx) = 1; GL(dl_tls_dtv_slotinfo_list) = &static_slotinfo.si; /* That is the size of the TLS memory for this object. */ GL(dl_tls_static_size) = (roundup (memsz, align ?: 1) # if TLS_TCB_AT_TP + tcbsize # endif ); /* The alignment requirement for the static TLS block. */ GL(dl_tls_static_align) = MAX (TLS_TCB_ALIGN, max_align); /* Number of elements in the static TLS block. */ GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx); } /* This is the minimal initialization function used when libpthread is not used. */ void __attribute__ ((weak)) __pthread_initialize_minimal (void) { __libc_setup_tls (TLS_INIT_TCB_SIZE, TLS_INIT_TCB_ALIGN); } #endif