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C++ constructors work with ELF load now

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git-svn-id: http://svn.code.sf.net/p/nuttx/code/trunk@5273 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo
2012-10-29 19:32:05 +00:00
parent 71fad980c5
commit 5681b615ec
28 changed files with 1282 additions and 394 deletions
Download Patch File Download Diff File Expand all files Collapse all files
nuttx/binfmt/libelf/Kconfig
-7
View File
@@ -32,13 +32,6 @@ config ELF_BUFFERINCR
will need to be read (such as symbol names). This value specifies the size
increment to use each time the buffer is reallocated. Default: 32
config ELF_CONSTRUCTORS
bool "C++ Static Constructor Support"
default n
depends on HAVE_CXX
---help---
Build in support for C++ constructors in ELF modules.
config ELF_DUMPBUFFER
bool "Dump ELF buffers"
default n
nuttx/binfmt/libelf/Make.defs
+4 -4
View File
@@ -41,11 +41,11 @@ BINFMT_CSRCS += elf.c
# ELF library
BINFMT_CSRCS += libelf_init.c libelf_uninit.c libelf_load.c \
libelf_unload.c libelf_verify.c libelf_read.c \
libelf_bind.c libelf_symbols.c libelf_iobuffer.c
BINFMT_CSRCS += libelf_bind.c libelf_init.c libelf_iobuffer.c libelf_load.c \
libelf_read.c libelf_sections.c libelf_symbols.c libelf_uninit.c \
libelf_unload.c libelf_verify.c
ifeq ($(CONFIG_ELF_CONSTRUCTORS),y)
ifeq ($(CONFIG_BINFMT_CONSTRUCTORS),y)
BINFMT_CSRCS += libelf_ctors.c
endif
nuttx/binfmt/libelf/libelf.h
+34 -20
View File
@@ -85,6 +85,39 @@ int elf_verifyheader(FAR const Elf32_Ehdr *header);
int elf_read(FAR struct elf_loadinfo_s *loadinfo, FAR uint8_t *buffer,
size_t readsize, off_t offset);
/****************************************************************************
* Name: elf_loadshdrs
*
* Description:
* Loads section headers into memory.
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
int elf_loadshdrs(FAR struct elf_loadinfo_s *loadinfo);
/****************************************************************************
* Name: elf_findsection
*
* Description:
* A section by its name.
*
* Input Parameters:
* loadinfo - Load state information
* sectname - Name of the section to find
*
* Returned Value:
* On success, the index to the section is returned; A negated errno value
* is returned on failure.
*
****************************************************************************/
int elf_findsection(FAR struct elf_loadinfo_s *loadinfo,
FAR const char *sectname);
/****************************************************************************
* Name: elf_findsymtab
*
@@ -199,27 +232,8 @@ int elf_reallocbuffer(FAR struct elf_loadinfo_s *loadinfo, size_t increment);
*
****************************************************************************/
#ifdef CONFIG_ELF_CONSTRUCTORS
#ifdef CONFIG_BINFMT_CONSTRUCTORS
int elf_loadctors(FAR struct elf_loadinfo_s *loadinfo);
#endif
/****************************************************************************
* Name: elf_doctors
*
* Description:
* Execute C++ static constructors.
*
* Input Parameters:
* loadinfo - Load state information
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
#ifdef CONFIG_ELF_CONSTRUCTORS
int elf_doctors(FAR struct elf_loadinfo_s *loadinfo);
#endif
#endif /* __BINFMT_LIBELF_LIBELF_H */
nuttx/binfmt/libelf/libelf_ctors.c
+69 -221
View File
@@ -49,7 +49,7 @@
#include "libelf.h"
#ifdef CONFIG_ELF_CONSTRUCTORS
#ifdef CONFIG_BINFMT_CONSTRUCTORS
/****************************************************************************
* Pre-Processor Definitions
@@ -67,166 +67,6 @@
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: elf_sectname
*
* Description:
* Get the symbol name in loadinfo->iobuffer[].
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
static inline int elf_sectname(FAR struct elf_loadinfo_s *loadinfo,
FAR const Elf32_Shdr *shdr)
{
FAR Elf32_Shdr *shstr;
FAR uint8_t *buffer;
off_t offset;
size_t readlen;
size_t bytesread;
int shstrndx;
int ret;
/* Get the section header table index of the entry associated with the
* section name string table. If the file has no section name string table,
* this member holds the value SH_UNDEF.
*/
shstrndx = loadinfo->ehdr.e_shstrndx;
if (shstrndx == SHN_UNDEF)
{
bdbg("No section header string table\n");
return -EINVAL;
}
/* Get the section name string table section header */
shstr = &loadinfo->shdr[shstrndx];
/* Get the file offset to the string that is the name of the section. This
* is the sum of:
*
* shstr->sh_offset: The file offset to the first byte of the section
* header string table data.
* shdr->sh_name: The offset to the name of the section in the section
* name table
*/
offset = shstr->sh_offset + shdr->sh_name;
/* Loop until we get the entire section name into memory */
buffer = loadinfo->iobuffer;
bytesread = 0;
for (;;)
{
/* Get the number of bytes to read */
readlen = loadinfo->buflen - bytesread;
if (offset + readlen > loadinfo->filelen)
{
readlen = loadinfo->filelen - offset;
if (readlen <= 0)
{
bdbg("At end of file\n");
return -EINVAL;
}
}
/* Read that number of bytes into the array */
buffer = &loadinfo->iobuffer[bytesread];
ret = elf_read(loadinfo, buffer, readlen, offset);
if (ret < 0)
{
bdbg("Failed to read section name\n");
return ret;
}
bytesread += readlen;
/* Did we read the NUL terminator? */
if (memchr(buffer, '\0', readlen) != NULL)
{
/* Yes, the buffer contains a NUL terminator. */
return OK;
}
/* No.. then we have to read more */
ret = elf_reallocbuffer(loadinfo, CONFIG_ELF_BUFFERINCR);
if (ret < 0)
{
bdbg("elf_reallocbuffer failed: %d\n", ret);
return ret;
}
}
/* We will not get here */
return OK;
}
/****************************************************************************
* Name: elf_findctors
*
* Description:
* Find C++ static constructors.
*
* Input Parameters:
* loadinfo - Load state information
*
* Returned Value:
* On success, the index to the CTOR section is returned; A negated errno
* value is returned on failure.
*
****************************************************************************/
static inline int elf_findctors(FAR struct elf_loadinfo_s *loadinfo)
{
FAR const Elf32_Shdr *shdr;
int ret;
int i;
/* Search through the shdr[] array in loadinfo for a section named .ctors */
for (i = 0; i < loadinfo->ehdr.e_shnum; i++)
{
/* Get the name of this section */
shdr = &loadinfo->shdr[i];
ret = elf_sectname(loadinfo, shdr);
if (ret < 0)
{
bdbg("elf_sectname failed: %d\n", ret);
return ret;
}
/* Check if the name of this section if ".ctors" */
bvdbg("%d. Comparing \"%s\" and .ctors\"\n", i, loadinfo->iobuffer);
if (strcmp(".ctors", (FAR const char *)loadinfo->iobuffer) == 0)
{
/* We found it... return the index */
return i;
}
}
/* We failed to find the .ctors sections. This may not be an error; maybe
* there are no static constructors.
*/
return -ENOENT;
}
/****************************************************************************
* Public Functions
****************************************************************************/
@@ -267,16 +107,21 @@ int elf_loadctors(FAR struct elf_loadinfo_s *loadinfo)
return -ENOMEM;
}
/* Find the index to the section named ".ctors" */
/* Find the index to the section named ".ctors." NOTE: On old ABI system,
* .ctors is the name of the section containing the list of constructors;
* On newer systems, the similar section is called .init_array. It is
* expected that the linker script will force the sectino name to be ".ctors"
* in either case.
*/
ctoridx = elf_findctors(loadinfo);
ctoridx = elf_findsection(loadinfo, ".ctors");
if (ctoridx < 0)
{
/* This may not be a failure. -ENOENT indicates that the file has no
* static constructor section.
*/
bvdbg("elf_findctors failed: %d\n", ctoridx);
bvdbg("elf_findsection .ctors section failed: %d\n", ctoridx);
return ret == -ENOENT ? OK : ret;
}
@@ -286,7 +131,9 @@ int elf_loadctors(FAR struct elf_loadinfo_s *loadinfo)
shdr = &loadinfo->shdr[ctoridx];
/* Allocate memory to hold a copy of the .ctor section */
/* Get the size of the .ctor section and the number of constructors that
* will need to be called.
*/
ctorsize = shdr->sh_size;
loadinfo->nctors = ctorsize / sizeof(elf_ctor_t);
@@ -302,71 +149,72 @@ int elf_loadctors(FAR struct elf_loadinfo_s *loadinfo)
{
/* Check an assumption that we made above */
DEBUGASSERT(shdr->sh_entsize == sizeof(elf_ctor_t));
DEBUGASSERT(shdr->sh_size == loadinfo->nctors * sizeof(elf_ctor_t));
loadinfo->ctors = (elf_ctor_t)kmalloc(ctorsize);
if (!loadinfo->ctors)
/* In the old ABI, the .ctors section is not allocated. In that case,
* we need to allocate memory to hold the .ctors and then copy the
* from the file into the allocated memory.
*
* SHF_ALLOC indicates that the section requires memory during
* execution.
*/
if ((shdr->sh_flags & SHF_ALLOC) == 0)
{
bdbg("Failed to allocate memory for .ctors\n");
return -ENOMEM;
/* Not loaded -> Old ABI. */
loadinfo->newabi = false;
/* Allocate memory to hold a copy of the .ctor section */
loadinfo->ctors = (elf_ctor_t*)kmalloc(ctorsize);
if (!loadinfo->ctors)
{
bdbg("Failed to allocate memory for .ctors\n");
return -ENOMEM;
}
/* Read the section header table into memory */
ret = elf_read(loadinfo, (FAR uint8_t*)loadinfo->ctors, ctorsize,
shdr->sh_offset);
if (ret < 0)
{
bdbg("Failed to allocate .ctors: %d\n", ret);
return ret;
}
/* Fix up all of the .ctor addresses. Since the addresses
* do not lie in allocated memory, there will be no relocation
* section for them.
*/
for (i = 0; i < loadinfo->nctors; i++)
{
FAR uintptr_t *ptr = (uintptr_t *)((FAR void *)(&loadinfo->ctors)[i]);
bvdbg("ctor %d: %08lx + %08lx = %08lx\n",
i, *ptr, loadinfo->alloc, *ptr + loadinfo->alloc);
*ptr += loadinfo->alloc;
}
}
/* Read the section header table into memory */
ret = elf_read(loadinfo, (FAR uint8_t*)loadinfo->ctors, ctorsize,
shdr->sh_offset);
if (ret < 0)
else
{
bdbg("Failed to allocate .ctors: %d\n", ret);
}
/* Loaded -> New ABI. */
/* Fix up all of the .ctor addresses */
loadinfo->newabi = true;
for (i = 0; i < loadinfo->nctors; i++)
{
FAR uintptr_t *ptr = (uintptr_t *)((FAR void *)(&loadinfo->ctors)[i]);
bvdbg("ctor %d: %08lx + %08lx = %08lx\n", i,
*ptr, loadinfo->alloc, *ptr + loadinfo->alloc);
*ptr += loadinfo->alloc;
/* Save the address of the .ctors (actually, .init_array) where it was
* loaded into memory. Since the .ctors lie in allocated memory, they
* will be relocated via the normal mechanism.
*/
loadinfo->ctors = (elf_ctor_t*)shdr->sh_addr;
}
}
return OK;
}
/****************************************************************************
* Name: elf_doctors
*
* Description:
* Execute C++ static constructors.
*
* Input Parameters:
* loadinfo - Load state information
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
int elf_doctors(FAR struct elf_loadinfo_s *loadinfo)
{
elf_ctor_t ctor = (elf_ctor_t)loadinfo->ctors;
int i;
/* Execute each constructor */
for (i = 0; i < loadinfo->nctors; i++)
{
bvdbg("Calling ctor %d at %p\n", i, (FAR void *)ctor);
ctor();
ctor++;
}
return OK;
}
#endif /* CONFIG_ELF_CONSTRUCTORS */
#endif /* CONFIG_BINFMT_CONSTRUCTORS */
nuttx/binfmt/libelf/libelf_load.c
+1 -57
View File
@@ -75,62 +75,6 @@
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: elf_loadshdrs
*
* Description:
* Loads section headers into memory.
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
static inline int elf_loadshdrs(FAR struct elf_loadinfo_s *loadinfo)
{
size_t shdrsize;
int ret;
DEBUGASSERT(loadinfo->shdr == NULL);
/* Verify that there are sections */
if (loadinfo->ehdr.e_shnum < 1)
{
bdbg("No sections(?)\n");
return -EINVAL;
}
/* Get the total size of the section header table */
shdrsize = (size_t)loadinfo->ehdr.e_shentsize * (size_t)loadinfo->ehdr.e_shnum;
if(loadinfo->ehdr.e_shoff + shdrsize > loadinfo->filelen)
{
bdbg("Insufficent space in file for section header table\n");
return -ESPIPE;
}
/* Allocate memory to hold a working copy of the sector header table */
loadinfo->shdr = (FAR Elf32_Shdr*)kmalloc(shdrsize);
if (!loadinfo->shdr)
{
bdbg("Failed to allocate the section header table. Size: %ld\n", (long)shdrsize);
return -ENOMEM;
}
/* Read the section header table into memory */
ret = elf_read(loadinfo, (FAR uint8_t*)loadinfo->shdr, shdrsize, loadinfo->ehdr.e_shoff);
if (ret < 0)
{
bdbg("Failed to read section header table: %d\n", ret);
}
return ret;
}
/****************************************************************************
* Name: elf_allocsize
*
@@ -292,7 +236,7 @@ int elf_load(FAR struct elf_loadinfo_s *loadinfo)
/* Find static constructors. */
#ifdef CONFIG_ELF_CONSTRUCTORS
#ifdef CONFIG_BINFMT_CONSTRUCTORS
ret = elf_loadctors(loadinfo);
if (ret < 0)
{
nuttx/binfmt/libelf/libelf_sections.c
+284
View File
@@ -0,0 +1,284 @@
/****************************************************************************
* binfmt/libelf/libelf_sections.c
*
* Copyright (C) 2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/kmalloc.h>
#include <nuttx/binfmt/elf.h>
#include "libelf.h"
/****************************************************************************
* Pre-Processor Definitions
****************************************************************************/
/****************************************************************************
* Private Constant Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: elf_sectname
*
* Description:
* Get the symbol name in loadinfo->iobuffer[].
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
static inline int elf_sectname(FAR struct elf_loadinfo_s *loadinfo,
FAR const Elf32_Shdr *shdr)
{
FAR Elf32_Shdr *shstr;
FAR uint8_t *buffer;
off_t offset;
size_t readlen;
size_t bytesread;
int shstrndx;
int ret;
/* Get the section header table index of the entry associated with the
* section name string table. If the file has no section name string table,
* this member holds the value SH_UNDEF.
*/
shstrndx = loadinfo->ehdr.e_shstrndx;
if (shstrndx == SHN_UNDEF)
{
bdbg("No section header string table\n");
return -EINVAL;
}
/* Get the section name string table section header */
shstr = &loadinfo->shdr[shstrndx];
/* Get the file offset to the string that is the name of the section. This
* is the sum of:
*
* shstr->sh_offset: The file offset to the first byte of the section
* header string table data.
* shdr->sh_name: The offset to the name of the section in the section
* name table
*/
offset = shstr->sh_offset + shdr->sh_name;
/* Loop until we get the entire section name into memory */
buffer = loadinfo->iobuffer;
bytesread = 0;
for (;;)
{
/* Get the number of bytes to read */
readlen = loadinfo->buflen - bytesread;
if (offset + readlen > loadinfo->filelen)
{
readlen = loadinfo->filelen - offset;
if (readlen <= 0)
{
bdbg("At end of file\n");
return -EINVAL;
}
}
/* Read that number of bytes into the array */
buffer = &loadinfo->iobuffer[bytesread];
ret = elf_read(loadinfo, buffer, readlen, offset);
if (ret < 0)
{
bdbg("Failed to read section name\n");
return ret;
}
bytesread += readlen;
/* Did we read the NUL terminator? */
if (memchr(buffer, '\0', readlen) != NULL)
{
/* Yes, the buffer contains a NUL terminator. */
return OK;
}
/* No.. then we have to read more */
ret = elf_reallocbuffer(loadinfo, CONFIG_ELF_BUFFERINCR);
if (ret < 0)
{
bdbg("elf_reallocbuffer failed: %d\n", ret);
return ret;
}
}
/* We will not get here */
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: elf_loadshdrs
*
* Description:
* Loads section headers into memory.
*
* Returned Value:
* 0 (OK) is returned on success and a negated errno is returned on
* failure.
*
****************************************************************************/
int elf_loadshdrs(FAR struct elf_loadinfo_s *loadinfo)
{
size_t shdrsize;
int ret;
DEBUGASSERT(loadinfo->shdr == NULL);
/* Verify that there are sections */
if (loadinfo->ehdr.e_shnum < 1)
{
bdbg("No sections(?)\n");
return -EINVAL;
}
/* Get the total size of the section header table */
shdrsize = (size_t)loadinfo->ehdr.e_shentsize * (size_t)loadinfo->ehdr.e_shnum;
if(loadinfo->ehdr.e_shoff + shdrsize > loadinfo->filelen)
{
bdbg("Insufficent space in file for section header table\n");
return -ESPIPE;
}
/* Allocate memory to hold a working copy of the sector header table */
loadinfo->shdr = (FAR Elf32_Shdr*)kmalloc(shdrsize);
if (!loadinfo->shdr)
{
bdbg("Failed to allocate the section header table. Size: %ld\n", (long)shdrsize);
return -ENOMEM;
}
/* Read the section header table into memory */
ret = elf_read(loadinfo, (FAR uint8_t*)loadinfo->shdr, shdrsize, loadinfo->ehdr.e_shoff);
if (ret < 0)
{
bdbg("Failed to read section header table: %d\n", ret);
}
return ret;
}
/****************************************************************************
* Name: elf_findsection
*
* Description:
* A section by its name.
*
* Input Parameters:
* loadinfo - Load state information
* sectname - Name of the section to find
*
* Returned Value:
* On success, the index to the section is returned; A negated errno value
* is returned on failure.
*
****************************************************************************/
int elf_findsection(FAR struct elf_loadinfo_s *loadinfo,
FAR const char *sectname)
{
FAR const Elf32_Shdr *shdr;
int ret;
int i;
/* Search through the shdr[] array in loadinfo for a section named 'sectname' */
for (i = 0; i < loadinfo->ehdr.e_shnum; i++)
{
/* Get the name of this section */
shdr = &loadinfo->shdr[i];
ret = elf_sectname(loadinfo, shdr);
if (ret < 0)
{
bdbg("elf_sectname failed: %d\n", ret);
return ret;
}
/* Check if the name of this section is 'sectname' */
bvdbg("%d. Comparing \"%s\" and .\"%s\"\n",
i, loadinfo->iobuffer, sectname);
if (strcmp((FAR const char *)loadinfo->iobuffer, sectname) == 0)
{
/* We found it... return the index */
return i;
}
}
/* We failed to find a section with this name. */
return -ENOENT;
}
nuttx/binfmt/libelf/libelf_uninit.c
-9
View File
@@ -115,15 +115,6 @@ int elf_freebuffers(struct elf_loadinfo_s *loadinfo)
loadinfo->shdr = NULL;
}
#ifdef CONFIG_ELF_CONSTRUCTORS
if (loadinfo->ctors)
{
kfree((FAR void *)loadinfo->ctors);
loadinfo->ctors = NULL;
loadinfo->nctors = 0;
}
#endif
if (loadinfo->iobuffer)
{
kfree((FAR void *)loadinfo->iobuffer);
nuttx/binfmt/libelf/libelf_unload.c
+20
View File
@@ -91,6 +91,26 @@ int elf_unload(struct elf_loadinfo_s *loadinfo)
loadinfo->allocsize = 0;
}
/* Release any allocated constructor memory */
#ifdef CONFIG_BINFMT_CONSTRUCTORS
if (loadinfo->ctors)
{
/* In the old ABI, the .ctors section is not make for allocation. In
* that case, we need to free the working buffer that was used to hold
* the constructors.
*/
if (!loadinfo->newabi)
{
kfree((FAR void *)loadinfo->ctors);
}
loadinfo->ctors = NULL;
loadinfo->nctors = 0;
}
#endif
return OK;
}