rpm/elfutils/libelf/elf_newscn.c

140 lines
3.6 KiB
C

/* Append new section.
Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
Written by Ulrich Drepper <drepper@redhat.com>, 1998.
This program is Open Source software; you can redistribute it and/or
modify it under the terms of the Open Software License version 1.0 as
published by the Open Source Initiative.
You should have received a copy of the Open Software License along
with this program; if not, you may obtain a copy of the Open Software
License version 1.0 from http://www.opensource.org/licenses/osl.php or
by writing the Open Source Initiative c/o Lawrence Rosen, Esq.,
3001 King Ranch Road, Ukiah, CA 95482. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <assert.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include "libelfP.h"
Elf_Scn *
elf_newscn (Elf *elf)
{
Elf_Scn *result = NULL;
bool first = false;
if (elf == NULL)
return NULL;
/* We rely on the prefix of the `elf', `elf32', and `elf64' element
being the same. */
assert (offsetof (Elf, state.elf.scns_last)
== offsetof (Elf, state.elf32.scns_last));
assert (offsetof (Elf, state.elf.scns_last)
== offsetof (Elf, state.elf64.scns_last));
assert (offsetof (Elf, state.elf32.scns)
== offsetof (Elf, state.elf64.scns));
rwlock_wrlock (elf->lock);
again:
if (elf->state.elf.scns_last->cnt < elf->state.elf.scns_last->max)
{
result = &elf->state.elf.scns_last->data[elf->state.elf.scns_last->cnt];
if (++elf->state.elf.scns_last->cnt == 1
&& (elf->state.elf.scns_last
== (elf->class == ELFCLASS32
|| (offsetof (Elf, state.elf32.scns)
== offsetof (Elf, state.elf64.scns))
? &elf->state.elf32.scns : &elf->state.elf64.scns)))
/* This is zeroth section. */
first = true;
else
{
assert (elf->state.elf.scns_last->cnt > 1);
result->index = result[-1].index + 1;
}
}
else
{
/* We must allocate a new element. */
Elf_ScnList *newp;
assert (elf->state.elf.scnincr > 0);
newp = (Elf_ScnList *) calloc (sizeof (Elf_ScnList)
+ ((elf->state.elf.scnincr *= 2)
* sizeof (Elf_Scn)), 1);
if (newp == NULL)
{
__libelf_seterrno (ELF_E_NOMEM);
goto out;
}
result = &newp->data[0];
/* One section used. */
++newp->cnt;
/* This is the number of sections we allocated. */
newp->max = elf->state.elf.scnincr;
/* Remember the index for the first section in this block. */
newp->data[0].index
= 1 + elf->state.elf.scns_last->data[elf->state.elf.scns_last->max - 1].index;
/* Enqueue the new list element. */
elf->state.elf.scns_last = elf->state.elf.scns_last->next = newp;
}
/* Create a section header for this section. */
if (elf->class == ELFCLASS32)
{
result->shdr.e32 = (Elf32_Shdr *) calloc (1, sizeof (Elf32_Shdr));
if (result->shdr.e32 == NULL)
{
__libelf_seterrno (ELF_E_NOMEM);
goto out;
}
}
else
{
result->shdr.e64 = (Elf64_Shdr *) calloc (1, sizeof (Elf64_Shdr));
if (result->shdr.e64 == NULL)
{
__libelf_seterrno (ELF_E_NOMEM);
goto out;
}
}
result->elf = elf;
result->shdr_flags = ELF_F_DIRTY | ELF_F_MALLOCED;
result->list = elf->state.elf.scns_last;
/* Initialize the data part. */
result->data_read = 1;
if (unlikely (first))
{
/* For the first section we mark the data as already available. */
//result->data_list_rear = &result->data_list;
first = false;
goto again;
}
result->flags |= ELF_F_DIRTY;
out:
rwlock_unlock (elf->lock);
return result;
}