/* Copyright (C) 2000,2004 Silicon Graphics, Inc. All Rights Reserved. Portions Copyright 2002-2010 Sun Microsystems, Inc. All rights reserved. Portions Copyright 2011-2019. David Anderson. All Rights Reserved. This program is free software; you can redistribute it and/or modify it under the terms of version 2.1 of the GNU Lesser General Public License as published by the Free Software Foundation. This program is distributed in the hope that it would be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Further, this software is distributed without any warranty that it is free of the rightful claim of any third person regarding infringement or the like. Any license provided herein, whether implied or otherwise, applies only to this software file. Patent licenses, if any, provided herein do not apply to combinations of this program with other software, or any other product whatsoever. You should have received a copy of the GNU Lesser General Public License along with this program; if not, write the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston MA 02110-1301, USA. */ #include "config.h" #include "pro_incl.h" #include #include "dwarf.h" #include "libdwarf.h" #include "pro_opaque.h" #include "pro_alloc.h" #ifdef HAVE_STDLIB_H #include #endif /* HAVE_STDLIB_H */ #ifdef HAVE_MALLOC_H /* Useful include for some Windows compilers. */ #include #endif /* HAVE_MALLOC_H */ #ifdef HAVE_STRING_H #include #endif /* HAVE_STRING_H */ #ifdef HAVE_STDINT_H #include /* For uintptr_t */ #endif /* HAVE_STDINT_H */ #ifdef HAVE_INTTYPES_H #include #endif /* HAVE_INTTYPES_H */ #include "dwarf_tsearch.h" /* When each block is allocated, there is a two-word structure allocated at the beginning so the block can go on a list. The address returned is the address *after* the two pointers at the start. But this allows us to be given a pointer to a generic block, and go backwards to find the list-node. Then we can remove this block from it's list without the need to search through a linked list in order to remove the node. It also allows us to 'delete' a memory block without needing the dbg structure. We still need the dbg structure on allocation so that we know which linked list to add the block to. Only the allocation of the dbg structure itself cannot use _dwarf_p_get_alloc. That structure should be set up by hand, and the two list pointers should be initialized to point at the node itself. That initializes the doubly linked list. */ #define LIST_TO_BLOCK(lst) ((void*) (((char *)lst) + sizeof(memory_list_t))) #define BLOCK_TO_LIST(blk) ((memory_list_t*) (((char*)blk) - sizeof(memory_list_t))) /* dbg should be NULL only when allocating dbg itself. In that case we initialize it to an empty circular doubly-linked list. */ Dwarf_Ptr _dwarf_p_get_alloc(Dwarf_P_Debug dbg, Dwarf_Unsigned size) { void *sp; memory_list_t *lp = NULL; memory_list_t *dbglp = NULL; memory_list_t *nextblock = NULL; /* alloc control struct and data block together for performance reasons */ lp = (memory_list_t *) malloc(size + sizeof(memory_list_t)); if (lp == NULL) { /* should throw an error */ return NULL; } /* point to 'size' bytes just beyond lp struct */ sp = LIST_TO_BLOCK(lp); memset(sp, 0, size); if (dbg == NULL) { lp->next = lp->prev = lp; } else { /* I always have to draw a picture to understand this part. */ dbglp = BLOCK_TO_LIST(dbg); nextblock = dbglp->next; /* Insert between dbglp and nextblock */ dbglp->next = lp; lp->prev = dbglp; lp->next = nextblock; nextblock->prev = lp; } return sp; } /* This routine is only here in case a caller of an older version of the library is calling this for some reason. This does nothing! No need to remove this block. In theory the user might be depending on the fact that we used to just 'free' this. In theory they might also be passing a block that they got from libdwarf. So we don't know if we should try to remove this block from our global list. Safest just to do nothing at this point. !!! This function is deprecated! Don't call it inside libdwarf or outside of it. Does nothing! !!! */ void dwarf_p_dealloc(UNUSEDARG Dwarf_Small * ptr) { return; } /* The dbg structure is not needed here anymore. */ void _dwarf_p_dealloc(UNUSEDARG Dwarf_P_Debug dbg, Dwarf_Small * ptr) /* ARGSUSED */ { memory_list_t *lp; lp = BLOCK_TO_LIST(ptr); /* Remove from a doubly linked, circular list. Read carefully, use a white board if necessary. If this is an empty list, the following statements are no-ops, and will write to the same memory location they read from. This should only happen when we deallocate the dbg structure itself. */ if (lp == lp->next) { /* The list has a single item, itself. */ lp->prev = 0; lp->next = 0; } else if (lp->next == lp->prev) { /* List had exactly two entries. Reduce it to one, cutting lp out. */ memory_list_t * remaining = lp->next; remaining->next = remaining; remaining->prev = remaining; } else { /* Multi=entry. Just cut lp out. */ lp->prev->next = lp->next; lp->next->prev = lp->prev; lp->prev = lp->next = 0; } free((void*)lp); } static void _dwarf_str_hashtab_freenode(void * nodep) { free(nodep); } /* This routine deallocates all the nodes on the dbg list, and then deallocates the dbg structure itself. */ void _dwarf_p_dealloc_all(Dwarf_P_Debug dbg) { memory_list_t *dbglp; memory_list_t *base_dbglp; if (dbg == NULL) { /* should throw an error */ return; } base_dbglp = BLOCK_TO_LIST(dbg); dbglp = base_dbglp->next; while (dbglp != base_dbglp) { memory_list_t*next = dbglp->next; _dwarf_p_dealloc(dbg, LIST_TO_BLOCK(dbglp)); dbglp = next; } dwarf_tdestroy(dbg->de_debug_str_hashtab, _dwarf_str_hashtab_freenode); dwarf_tdestroy(dbg->de_debug_line_str_hashtab, _dwarf_str_hashtab_freenode); free((void *)base_dbglp); }