nuttx/binfmt/libelf/libelf_verify.c
Stuart Ianna a05e8fd9ff binfmt/elf: Support loading fully linked executables.
The following changes make it possible for Nuttx to load binaries in ELF format which are fully linked.

The change does not include the necessary modifications to produce such binaries. In order to build an applicable binary:
 - The userspace applications linker script (`gnu-elf.ld`) needs to modified so the data and text section origin's match those setup by the address environment.
 - The makefile used, in `apps/import/Make.defs` needs to remove the `-r` LDELFFLAG.
2023-05-26 10:37:45 -03:00

111 lines
3.6 KiB
C

/****************************************************************************
* binfmt/libelf/libelf_verify.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
#include <debug.h>
#include <errno.h>
#include <nuttx/elf.h>
#include <nuttx/binfmt/elf.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Constant Data
****************************************************************************/
static const char g_elfmagic[EI_MAGIC_SIZE] =
{
0x7f, 'E', 'L', 'F'
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: elf_verifyheader
*
* Description:
* Given the header from a possible ELF executable, verify that it
* is an ELF executable.
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
* -ENOEXEC : Not an ELF file
* -EINVAL : Not a relocatable ELF file or not supported by the current,
* configured architecture.
*
****************************************************************************/
int elf_verifyheader(FAR const Elf_Ehdr *ehdr)
{
if (!ehdr)
{
berr("NULL ELF header!");
return -ENOEXEC;
}
/* Verify that the magic number indicates an ELF file */
if (memcmp(ehdr->e_ident, g_elfmagic, EI_MAGIC_SIZE) != 0)
{
binfo("Not ELF magic {%02x, %02x, %02x, %02x}\n",
ehdr->e_ident[0], ehdr->e_ident[1], ehdr->e_ident[2],
ehdr->e_ident[3]);
return -ENOEXEC;
}
/* Verify that this is a relocatable file */
if ((ehdr->e_type != ET_REL) && (ehdr->e_type != ET_EXEC))
{
berr("Not a relocatable or executable file: e_type=%d\n",
ehdr->e_type);
return -EINVAL;
}
/* Verify that this file works with the currently configured architecture */
if (!up_checkarch(ehdr))
{
berr("Not a supported architecture\n");
return -ENOEXEC;
}
/* Looks good so far... we still might find some problems later. */
return OK;
}