xref: /illumos-gate/usr/src/lib/libdwarf/common/pro_reloc_symbolic.c (revision 4d9fdb46b215739778ebc12079842c9905586999)

/*

  Copyright (C) 2000,2004 Silicon Graphics, Inc.  All Rights Reserved.
  Portions Copyright 2016 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 "libdwarfdefs.h"
#include <stdio.h>
#ifdef HAVE_STRING_H
#include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STDDEF_H
#include <stddef.h>
#endif /* HAVE_STDDEF_H */
/*#include <elfaccess.h> */
#include "pro_incl.h"
#include "dwarf.h"
#include "libdwarf.h"
#include "pro_opaque.h"
#include "pro_error.h"
#include "pro_alloc.h"
#include "pro_section.h"
#include "pro_reloc.h"
#include "pro_reloc_symbolic.h"

#ifndef SHT_REL
#define SHT_REL 9
#endif /* SHT_REL */
#ifndef SHN_UNDEF
#define SHN_UNDEF 0
#endif /* SHN_UNDEF */

/*  Return DW_DLV_ERROR on malloc error.
    Return DW_DLV_OK otherwise */

int
_dwarf_pro_reloc_name_symbolic(Dwarf_P_Debug dbg,
    int base_sec_index,
    Dwarf_Unsigned offset, /* r_offset of reloc */
    Dwarf_Unsigned symidx,
    enum Dwarf_Rel_Type type,
    int reltarget_length)
{
    /* get a slot, fill in the slot entry */
    void *relrec_to_fill = 0;
    int res = 0;
    struct Dwarf_Relocation_Data_s *slotp;

    res = _dwarf_pro_reloc_get_a_slot(dbg, base_sec_index,
        &relrec_to_fill);
    if (res != DW_DLV_OK)
        return res;
    slotp = (struct Dwarf_Relocation_Data_s *) relrec_to_fill;
    slotp->drd_type = type;
    slotp->drd_length = reltarget_length;
    slotp->drd_offset = offset;
    slotp->drd_symbol_index = symidx;
    return DW_DLV_OK;
}



/*  Return DW_DLV_ERROR on malloc error.
    Return DW_DLV_OK otherwise */
int
_dwarf_pro_reloc_length_symbolic(Dwarf_P_Debug dbg,
    int base_sec_index,
    Dwarf_Unsigned offset,  /* r_offset of reloc */
    Dwarf_Unsigned start_symidx,
    Dwarf_Unsigned end_symidx,
    enum Dwarf_Rel_Type type,
    int reltarget_length)
{
    /* get a slot, fill in the slot entry */
    void *relrec_to_fill = 0;
    int res = 0;
    struct Dwarf_Relocation_Data_s *slotp1 = 0;
    struct Dwarf_Relocation_Data_s *slotp2 = 0;

    res = _dwarf_pro_reloc_get_a_slot(dbg, base_sec_index,
        &relrec_to_fill);
    if (res != DW_DLV_OK)
        return res;
    slotp1 = (struct Dwarf_Relocation_Data_s *) relrec_to_fill;
    res = _dwarf_pro_reloc_get_a_slot(dbg, base_sec_index,
        &relrec_to_fill);
    if (res != DW_DLV_OK)
        return res;
    slotp2 = (struct Dwarf_Relocation_Data_s *) relrec_to_fill;

    /* ASSERT: type == dwarf_drt_first_of_length_type_pair */
    slotp1->drd_type = type;
    slotp1->drd_length = reltarget_length;
    slotp1->drd_offset = offset;
    slotp1->drd_symbol_index = start_symidx;

    slotp2->drd_type = dwarf_drt_second_of_length_pair;
    slotp2->drd_length = reltarget_length;
    slotp2->drd_offset = offset;
    slotp2->drd_symbol_index = end_symidx;
    return DW_DLV_OK;
}

/*  Ensure each stream is a single buffer and
    add that single buffer to the set of stream buffers.

    By creating a new buffer and copying if necessary.
    (If > 1 block, reduce to 1 block)

    Free the input set of buffers if we consolidate.

    We pass back *new_sec_count as zero because we
    are not creating normal sections for a .o, but
    symbolic relocations, separately counted.

    Return -1 on error (malloc failure)

    Return DW_DLV_OK on success. Any other return indicates
    malloc failed.  */
int
_dwarf_symbolic_relocs_to_disk(Dwarf_P_Debug dbg,
    Dwarf_Signed * new_sec_count)
{
    int i = 0;
    Dwarf_Error error = 0;

    for (i = 0; i < NUM_DEBUG_SECTIONS; ++i) {
        int sec_index = 0;
        Dwarf_P_Per_Reloc_Sect p_reloc = dbg->de_reloc_sect + i;
        unsigned long ct = p_reloc->pr_reloc_total_count;
        int err = 0;
        if (ct == 0) {
            /*  No relocations in here. Nothing to do. */
            continue;
        }

        /* total_size = ct *len; */
        sec_index = p_reloc->pr_sect_num_of_reloc_sect;
        if (sec_index == 0) {
            /*  sec_index zero means we have not processed this
                section of relocations yet. */
            /*  Call de_callback_func
                getting section number of reloc section. */
            int rel_section_index = 0;
            Dwarf_Unsigned name_idx = 0;

            /*  This is a bit of a fake, as we do not really have true
                elf sections at all. Just the data such might contain.
                But this lets the caller eventually link things
                together: without this call we would not know what rel
                data goes with what section when we are asked for the
                real arrays. */

            if (dbg->de_callback_func) {
                /*  For symbolic relocations de_callback_func
                    may well return 0.  */
                rel_section_index =
                    dbg->de_callback_func(_dwarf_rel_section_names[i],
                        dbg->de_relocation_record_size,
                        /* type */ SHT_REL,
                        /* flags */ 0,
                        /* link to symtab, which we cannot
                            know */ SHN_UNDEF,
                        /* sec rels apply to */
                        dbg->de_elf_sects[i],
                        &name_idx,
                        dbg->de_user_data,&err);
            }
            if (rel_section_index == -1) {
                {
                    _dwarf_p_error(dbg, &error, DW_DLE_ELF_SECT_ERR);
                    return (DW_DLV_ERROR);
                }
            }
            p_reloc->pr_sect_num_of_reloc_sect = rel_section_index;
        }


        /*  If pr_block_count 0 or 1 then the blocks are
            an array (with 0 or 1 entries) so we'll just
            return to the for loop. No more work to do here.  */
        if (p_reloc->pr_block_count < 2) {
            continue;
        }
        {
            /*  Since more than one relocation on the section
                we now convert the list of relocation blocks
                into a proper array of blocks. */
            struct Dwarf_P_Relocation_Block_s *new_blk = 0;
            struct Dwarf_P_Relocation_Block_s *p_blk = 0;
            Dwarf_Small *data = 0;
            int res = 0;

            p_blk = p_reloc->pr_first_block;
            /* Do not zero pr_sect_num_of_reloc_sect */
            p_reloc->pr_reloc_total_count = 0;
            p_reloc->pr_first_block = 0;
            p_reloc->pr_last_block = 0;
            p_reloc->pr_block_count = 0;
            /*  Now we know a number making a single
                array. Replaces DEFAULT_SLOTS_PER_BLOCK */
            p_reloc->pr_slots_per_block_to_alloc = ct;

            /*  Creating new single block for all 'ct' entries.
                Assigns a pointer value to pr_first_block
                (which means our p_reloc).
                It updates p_reloc->pr_first_block */
            res = _dwarf_pro_pre_alloc_specific_reloc_slots(dbg,
                p_reloc,ct);
            if (res != DW_DLV_OK) {
                return res;
            }

            new_blk = p_reloc->pr_first_block;
            data = (Dwarf_Small *) new_blk->rb_data;

            /*  The following loop does the consolidation to a single
                block and frees the input block(s).
                p_blk points to the old singly-linked-list
                    and is the
                    only access to that list.
                data is a pointer to the new array of ct entries
                which is our target(destination) of the copies.
                */
            do {
                struct Dwarf_P_Relocation_Block_s *p_blk_last = 0;
                /*  len identifies the data in all the slots
                    in use in this block. */
                unsigned long len =
                    p_blk->rb_where_to_add_next - p_blk->rb_data;
                memcpy(data, p_blk->rb_data, len);
                data += len;
                p_blk_last = p_blk;
                p_blk = p_blk->rb_next;
                _dwarf_p_dealloc(dbg, (Dwarf_Small *) p_blk_last);
            } while (p_blk);
            /*  ASSERT: the dangling p_blk list all dealloc'd
                which is really a no-op, all deallocations
                take place at producer_finish().  */
            /* ASSERT: sum of len copied == total_size */
            new_blk->rb_next_slot_to_use = ct;
            new_blk->rb_where_to_add_next = (char *) data;
            p_reloc->pr_reloc_total_count = ct;

            /*  Have now created a single block, but no
                change in slots used (pr_reloc_total_count) */
        }
    }
    /*  There is no section data with symbolic,
        so there is no count. */
    *new_sec_count = 0;
    return DW_DLV_OK;
}