221 lines
7.2 KiB
C
221 lines
7.2 KiB
C
/****************************************************************************
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* binfmt/libelf/libelf_ctors.c
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*
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* Copyright (C) 2012 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <string.h>
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#include <errno.h>
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#include <assert.h>
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#include <debug.h>
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#include <nuttx/kmalloc.h>
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#include <nuttx/binfmt/elf.h>
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#include "libelf.h"
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#ifdef CONFIG_BINFMT_CONSTRUCTORS
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/****************************************************************************
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* Pre-Processor Definitions
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****************************************************************************/
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/****************************************************************************
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* Private Types
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****************************************************************************/
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/****************************************************************************
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* Private Constant Data
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****************************************************************************/
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: elf_loadctors
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*
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* Description:
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* Load points to static constructors into an in-memory array.
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*
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* Input Parameters:
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* loadinfo - Load state information
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*
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* Returned Value:
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* 0 (OK) is returned on success and a negated errno is returned on
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* failure.
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*
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****************************************************************************/
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int elf_loadctors(FAR struct elf_loadinfo_s *loadinfo)
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{
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FAR Elf32_Shdr *shdr;
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size_t ctorsize;
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int ctoridx;
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int ret;
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int i;
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DEBUGASSERT(loadinfo->ctors == NULL);
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/* Allocate an I/O buffer. This buffer is used by elf_sectname() to
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* accumulate the variable length symbol name.
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*/
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ret = elf_allocbuffer(loadinfo);
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if (ret < 0)
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{
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bdbg("elf_allocbuffer failed: %d\n", ret);
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return -ENOMEM;
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}
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/* Find the index to the section named ".ctors." NOTE: On old ABI system,
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* .ctors is the name of the section containing the list of constructors;
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* On newer systems, the similar section is called .init_array. It is
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* expected that the linker script will force the sectino name to be ".ctors"
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* in either case.
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*/
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ctoridx = elf_findsection(loadinfo, ".ctors");
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if (ctoridx < 0)
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{
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/* This may not be a failure. -ENOENT indicates that the file has no
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* static constructor section.
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*/
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bvdbg("elf_findsection .ctors section failed: %d\n", ctoridx);
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return ret == -ENOENT ? OK : ret;
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}
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/* Now we can get a pointer to the .ctor section in the section header
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* table.
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*/
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shdr = &loadinfo->shdr[ctoridx];
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/* Get the size of the .ctor section and the number of constructors that
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* will need to be called.
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*/
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ctorsize = shdr->sh_size;
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loadinfo->nctors = ctorsize / sizeof(elf_ctor_t);
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bvdbg("ctoridx=%d ctorsize=%d sizeof(elf_ctor_t)=%d nctors=%d\n",
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ctoridx, ctorsize, sizeof(elf_ctor_t), loadinfo->nctors);
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/* Check if there are any constructors. It is not an error if there
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* are none.
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*/
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if (loadinfo->nctors > 0)
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{
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/* Check an assumption that we made above */
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DEBUGASSERT(shdr->sh_size == loadinfo->nctors * sizeof(elf_ctor_t));
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/* In the old ABI, the .ctors section is not allocated. In that case,
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* we need to allocate memory to hold the .ctors and then copy the
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* from the file into the allocated memory.
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*
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* SHF_ALLOC indicates that the section requires memory during
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* execution.
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*/
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if ((shdr->sh_flags & SHF_ALLOC) == 0)
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{
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/* Not loaded -> Old ABI. */
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loadinfo->newabi = false;
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/* Allocate memory to hold a copy of the .ctor section */
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loadinfo->ctors = (elf_ctor_t*)kmalloc(ctorsize);
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if (!loadinfo->ctors)
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{
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bdbg("Failed to allocate memory for .ctors\n");
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return -ENOMEM;
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}
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/* Read the section header table into memory */
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ret = elf_read(loadinfo, (FAR uint8_t*)loadinfo->ctors, ctorsize,
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shdr->sh_offset);
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if (ret < 0)
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{
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bdbg("Failed to allocate .ctors: %d\n", ret);
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return ret;
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}
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/* Fix up all of the .ctor addresses. Since the addresses
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* do not lie in allocated memory, there will be no relocation
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* section for them.
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*/
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for (i = 0; i < loadinfo->nctors; i++)
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{
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FAR uintptr_t *ptr = (uintptr_t *)((FAR void *)(&loadinfo->ctors)[i]);
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bvdbg("ctor %d: %08lx + %08lx = %08lx\n",
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i, *ptr, loadinfo->alloc, *ptr + loadinfo->alloc);
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*ptr += loadinfo->alloc;
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}
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}
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else
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{
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/* Loaded -> New ABI. */
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loadinfo->newabi = true;
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/* Save the address of the .ctors (actually, .init_array) where it was
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* loaded into memory. Since the .ctors lie in allocated memory, they
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* will be relocated via the normal mechanism.
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*/
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loadinfo->ctors = (elf_ctor_t*)shdr->sh_addr;
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}
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}
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return OK;
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}
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#endif /* CONFIG_BINFMT_CONSTRUCTORS */
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