Finish implemention of ELF loader static constructor support. Still some issues.

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5272 42af7a65-404d-4744-a932-0658087f49c3

binfmt/elf.c

@@ -116,6 +116,7 @@ static void elf_dumploadinfo(FAR struct elf_loadinfo_s *loadinfo)
   bdbg("  filelen:      %ld\n",   (long)loadinfo->filelen);
 #ifdef CONFIG_ELF_CONSTRUCTORS
   bdbg("  ctors:        %08lx\n", (long)loadinfo->ctors);
+  bdbg("  nctors:       %d\n",    loadinfo->nctors);
 #endif
   bdbg("  filfd:        %d\n",    loadinfo->filfd);
   bdbg("  symtabidx:    %d\n",    loadinfo->symtabidx);

binfmt/libelf/Make.defs

@@ -43,7 +43,7 @@ BINFMT_CSRCS += elf.c
 
 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_bind.c libelf_symbols.c libelf_iobuffer.c
 
 ifeq ($(CONFIG_ELF_CONSTRUCTORS),y)
 BINFMT_CSRCS += libelf_ctors.c

binfmt/libelf/libelf.h

@@ -141,6 +141,49 @@ int elf_readsym(FAR struct elf_loadinfo_s *loadinfo, int index,
 int elf_symvalue(FAR struct elf_loadinfo_s *loadinfo, FAR Elf32_Sym *sym,
                  FAR const struct symtab_s *exports, int nexports);
 
+/****************************************************************************
+ * Name: elf_freebuffers
+ *
+ * Description:
+ *  Release all working buffers.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_freebuffers(FAR struct elf_loadinfo_s *loadinfo);
+
+/****************************************************************************
+ * Name: elf_allocbuffer
+ *
+ * Description:
+ *   Perform the initial allocation of the I/O buffer, if it has not already
+ *   been allocated.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_allocbuffer(FAR struct elf_loadinfo_s *loadinfo);
+
+/****************************************************************************
+ * Name: elf_reallocbuffer
+ *
+ * Description:
+ *   Increase the size of I/O buffer by the specified buffer increment.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_reallocbuffer(FAR struct elf_loadinfo_s *loadinfo, size_t increment);
+
 /****************************************************************************
  * Name: elf_findctors
  *
@@ -157,7 +200,7 @@ int elf_symvalue(FAR struct elf_loadinfo_s *loadinfo, FAR Elf32_Sym *sym,
  ****************************************************************************/
 
 #ifdef CONFIG_ELF_CONSTRUCTORS
-int elf_findctors(FAR struct elf_loadinfo_s *loadinfo);
+int elf_loadctors(FAR struct elf_loadinfo_s *loadinfo);
 #endif
 
 /****************************************************************************

binfmt/libelf/libelf_bind.c

@@ -46,7 +46,6 @@
 #include <assert.h>
 #include <debug.h>
 
-#include <nuttx/kmalloc.h>
 #include <nuttx/binfmt/elf.h>
 #include <nuttx/binfmt/symtab.h>
 
@@ -247,17 +246,16 @@ int elf_bind(FAR struct elf_loadinfo_s *loadinfo,
       return ret;
     }
 
-  /* Allocate an I/O buffer.  This buffer is used only by elf_symname() to
+  /* Allocate an I/O buffer.  This buffer is used by elf_symname() to
    * accumulate the variable length symbol name.
    */
 
-  loadinfo->iobuffer = (FAR uint8_t *)kmalloc(CONFIG_ELF_BUFFERSIZE);
-  if (!loadinfo->iobuffer)
+  ret = elf_allocbuffer(loadinfo);
+  if (ret < 0)
     {
-      bdbg("Failed to allocate an I/O buffer\n");
+      bdbg("elf_allocbuffer failed: %d\n", ret);
       return -ENOMEM;
     }
-  loadinfo->buflen = CONFIG_ELF_BUFFERSIZE;
 
   /* Process relocations in every allocated section */
 
@@ -303,11 +301,6 @@ int elf_bind(FAR struct elf_loadinfo_s *loadinfo,
   arch_flushicache((FAR void*)loadinfo->alloc, loadinfo->allocsize);
 #endif
 
-  /* Free the I/O buffer */
-
-  kfree(loadinfo->iobuffer);
-  loadinfo->iobuffer = NULL;
-  loadinfo->buflen   = 0;
   return ret;
 }
 

binfmt/libelf/libelf_ctors.c

@@ -39,11 +39,15 @@
 
 #include <nuttx/config.h>
 
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
 #include <debug.h>
 
+#include <nuttx/kmalloc.h>
 #include <nuttx/binfmt/elf.h>
 
-#include "libelf"
+#include "libelf.h"
 
 #ifdef CONFIG_ELF_CONSTRUCTORS
 
@@ -55,8 +59,6 @@
  * Private Types
  ****************************************************************************/
 
-typedef FAR void (*ctor_t)(void);
-
 /****************************************************************************
  * Private Constant Data
  ****************************************************************************/
@@ -66,9 +68,111 @@ typedef FAR void (*ctor_t)(void);
  ****************************************************************************/
 
 /****************************************************************************
- * Public 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
  *
@@ -79,27 +183,157 @@ typedef FAR void (*ctor_t)(void);
  *   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
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_loadctors
+ *
+ * Description:
+ *  Load points to static constructors into an in-memory array.
+ *
+ * Input Parameters:
+ *   loadinfo - Load state information
+ *
+ * Returned Value:
  *   0 (OK) is returned on success and a negated errno is returned on
  *   failure.
  *
  ****************************************************************************/
 
-int elf_findctors(FAR struct elf_loadinfo_s *loadinfo)
+int elf_loadctors(FAR struct elf_loadinfo_s *loadinfo)
 {
-  /* Search through the shdr[] array in loadinfo for a section named .ctors */
-#warning "Missing logic"
+  FAR Elf32_Shdr *shdr;
+  size_t ctorsize;
+  int ctoridx;
+  int ret;
+  int i;
 
-  /* Get the address of the beginning of the constructros from the sh_addr
-   * field of the section.  Save that in the ctors field of the loadinfo
-   * structure.
+  DEBUGASSERT(loadinfo->ctors == NULL);
+
+  /* Allocate an I/O buffer.  This buffer is used by elf_sectname() to
+   * accumulate the variable length symbol name.
    */
-#warning "Missing logic"
 
-  /* Get the number of constructors from the sh_size field of the section.
-   * Save that number in the nctors field of the loadinfo structure.
-   */ 
-#warning "Missing logic"
-  return -ENOSYS;
+  ret = elf_allocbuffer(loadinfo);
+  if (ret < 0)
+    {
+      bdbg("elf_allocbuffer failed: %d\n", ret);
+      return -ENOMEM;
+    }
+
+  /* Find the index to the section named ".ctors" */
+
+  ctoridx = elf_findctors(loadinfo);
+  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);
+      return ret == -ENOENT ? OK : ret;
+    }
+
+  /* Now we can get a pointer to the .ctor section in the section header
+   * table.
+   */
+
+  shdr = &loadinfo->shdr[ctoridx];
+
+  /* Allocate memory to hold a copy of the .ctor section */
+
+  ctorsize         = shdr->sh_size;
+  loadinfo->nctors = ctorsize / sizeof(elf_ctor_t);
+
+  bvdbg("ctoridx=%d ctorsize=%d sizeof(elf_ctor_t)=%d nctors=%d\n",
+        ctoridx, ctorsize,  sizeof(elf_ctor_t), loadinfo->nctors);
+
+  /* Check if there are any constructors.  It is not an error if there
+   * are none.
+   */
+
+  if (loadinfo->nctors > 0)
+    {
+      /* Check an assumption that we made above */
+
+      DEBUGASSERT(shdr->sh_entsize == sizeof(elf_ctor_t));
+
+      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);
+        }
+
+      /* Fix up all of the .ctor addresses */
+
+      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;
+        }
+    }
+
+  return OK;
 }
 
 /****************************************************************************
@@ -119,16 +353,20 @@ int elf_findctors(FAR struct elf_loadinfo_s *loadinfo)
 
 int elf_doctors(FAR struct elf_loadinfo_s *loadinfo)
 {
-  ctor_t ctor = (ctor_t)loadinfo->ctors;
+  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_ELF_CONSTRUCTORS */

binfmt/libelf/libelf_iobuffer.c

@@ -0,0 +1,136 @@
+/****************************************************************************
+ * binfmt/libelf/elf_iobuffer.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 <debug.h>
+#include <errno.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/binfmt/elf.h>
+
+#include "libelf.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Constant Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: elf_allocbuffer
+ *
+ * Description:
+ *   Perform the initial allocation of the I/O buffer, if it has not already
+ *   been allocated.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_allocbuffer(FAR struct elf_loadinfo_s *loadinfo)
+{
+  /* Has a buffer been allocated> */
+
+  if (!loadinfo->iobuffer)
+    {
+      /* No.. allocate one now */
+ 
+      loadinfo->iobuffer = (FAR uint8_t *)kmalloc(CONFIG_ELF_BUFFERSIZE);
+      if (!loadinfo->iobuffer)
+        {
+          bdbg("Failed to allocate an I/O buffer\n");
+          return -ENOMEM;
+        }
+
+      loadinfo->buflen = CONFIG_ELF_BUFFERSIZE;
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: elf_reallocbuffer
+ *
+ * Description:
+ *   Increase the size of I/O buffer by the specified buffer increment.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_reallocbuffer(FAR struct elf_loadinfo_s *loadinfo, size_t increment)
+{
+  FAR void *buffer;
+  size_t newsize;
+
+  /* Get the new size of the allocation */
+
+  newsize = loadinfo->buflen + increment;
+
+  /* And perform the reallocation */
+
+   buffer = krealloc((FAR void *)loadinfo->iobuffer, newsize);
+   if (!buffer)
+    {
+      bdbg("Failed to reallocate the I/O buffer\n");
+      return -ENOMEM;
+    }
+
+  /* Save the new buffer info */
+
+  loadinfo->iobuffer = buffer;
+  loadinfo->buflen   = newsize;
+  return OK;
+}
+

binfmt/libelf/libelf_load.c

@@ -126,14 +126,8 @@ static inline int elf_loadshdrs(FAR struct elf_loadinfo_s *loadinfo)
   if (ret < 0)
     {
       bdbg("Failed to read section header table: %d\n", ret);
-      goto errout_with_alloc;
     }
 
-  return OK;
-
-errout_with_alloc:
-  kfree(loadinfo->shdr);
-  loadinfo->shdr = 0;
   return ret;
 }
 
@@ -233,7 +227,7 @@ static inline int elf_loadfile(FAR struct elf_loadinfo_s *loadinfo)
           if (ret < 0)
             {
               bdbg("Failed to read section %d: %d\n", i, ret);
-              goto errout_with_alloc;
+              return ret;
             }
         }
 
@@ -248,11 +242,6 @@ static inline int elf_loadfile(FAR struct elf_loadinfo_s *loadinfo)
     }
 
   return OK;
-
-errout_with_alloc:
-  kfree((FAR void*)loadinfo->alloc);
-  loadinfo->alloc = 0;
-  return ret;
 }
 
 /****************************************************************************
@@ -285,7 +274,7 @@ int elf_load(FAR struct elf_loadinfo_s *loadinfo)
   if (ret < 0)
     {
       bdbg("elf_loadshdrs failed: %d\n", ret);
-      return ret;
+      goto errout_with_buffers;
     }
 
   /* Determine total size to allocate */
@@ -298,16 +287,17 @@ int elf_load(FAR struct elf_loadinfo_s *loadinfo)
   if (ret < 0)
     {
       bdbg("elf_loadfile failed: %d\n", ret);
-      goto errout_with_shdrs;
+      goto errout_with_buffers;
     }
 
   /* Find static constructors. */
 
 #ifdef CONFIG_ELF_CONSTRUCTORS
-  ret = elf_findctors(loadinfo);
+  ret = elf_loadctors(loadinfo);
+  if (ret < 0)
     {
-      bdbg("elf_findctors failed: %d\n", ret);
-      goto errout_with_shdrs;
+      bdbg("elf_loadctors failed: %d\n", ret);
+      goto errout_with_buffers;
     }
 #endif
 
@@ -315,9 +305,8 @@ int elf_load(FAR struct elf_loadinfo_s *loadinfo)
 
   /* Error exits */
 
-errout_with_shdrs:
-  kfree(loadinfo->shdr);
-  loadinfo->shdr = NULL;
+errout_with_buffers:
+  elf_freebuffers(loadinfo);
   return ret;
 }
 

binfmt/libelf/libelf_symbols.c

@@ -101,7 +101,6 @@ static int elf_symname(FAR struct elf_loadinfo_s *loadinfo,
 
   /* Loop until we get the entire symbol name into memory */
 
-  buffer    = loadinfo->iobuffer;
   bytesread = 0;
 
   for (;;)
@@ -125,7 +124,7 @@ static int elf_symname(FAR struct elf_loadinfo_s *loadinfo,
       ret = elf_read(loadinfo, buffer, readlen, offset);
       if (ret < 0)
         {
-          bdbg("Failed to read symbol name\n");
+          bdbg("elf_read failed: %d\n", ret);
           return ret;
         }
 
@@ -142,18 +141,12 @@ static int elf_symname(FAR struct elf_loadinfo_s *loadinfo,
 
       /* No.. then we have to read more */
 
-      buffer = realloc((FAR void *)loadinfo->iobuffer,
-                       loadinfo->buflen + CONFIG_ELF_BUFFERINCR);
-      if (!buffer)
+      ret = elf_reallocbuffer(loadinfo, CONFIG_ELF_BUFFERINCR);
+      if (ret < 0)
         {
-          bdbg("Failed to reallocate the I/O buffer\n");
-          return -ENOMEM;
+          bdbg("elf_reallocbuffer failed: %d\n", ret);
+          return ret;
         }
-
-      /* Save the new buffer info */
-
-      loadinfo->iobuffer = buffer;
-      loadinfo->buflen   += CONFIG_ELF_BUFFERINCR;
     }
 
   /* We will not get here */

binfmt/libelf/libelf_uninit.c

@@ -42,8 +42,12 @@
 #include <unistd.h>
 #include <debug.h>
 #include <errno.h>
+
+#include <nuttx/kmalloc.h>
 #include <nuttx/binfmt/elf.h>
 
+#include "libelf.h"
+
 /****************************************************************************
  * Pre-Processor Definitions
  ****************************************************************************/
@@ -75,6 +79,12 @@
 
 int elf_uninit(struct elf_loadinfo_s *loadinfo)
 {
+  /* Free all working buffers */
+
+  elf_freebuffers(loadinfo);
+
+  /* Close the ELF file */
+
   if (loadinfo->filfd >= 0)
     {
       close(loadinfo->filfd);
@@ -83,3 +93,43 @@ int elf_uninit(struct elf_loadinfo_s *loadinfo)
   return OK;
 }
 
+/****************************************************************************
+ * Name: elf_freebuffers
+ *
+ * Description:
+ *  Release all working buffers.
+ *
+ * Returned Value:
+ *   0 (OK) is returned on success and a negated errno is returned on
+ *   failure.
+ *
+ ****************************************************************************/
+
+int elf_freebuffers(struct elf_loadinfo_s *loadinfo)
+{
+  /* Release all working allocations  */
+
+  if (loadinfo->shdr)
+    {
+      kfree((FAR void *)loadinfo->shdr);
+      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);
+      loadinfo->iobuffer  = NULL;
+      loadinfo->buflen    = 0;
+    }
+
+  return OK;
+}

binfmt/libelf/libelf_unload.c

@@ -45,6 +45,8 @@
 #include <nuttx/kmalloc.h>
 #include <nuttx/binfmt/elf.h>
 
+#include "libelf.h"
+
 /****************************************************************************
  * Pre-Processor Definitions
  ****************************************************************************/
@@ -76,7 +78,11 @@
 
 int elf_unload(struct elf_loadinfo_s *loadinfo)
 {
-  /* Release the all allocated memory */
+  /* Free all working buffers */
+
+  elf_freebuffers(loadinfo);
+
+  /* Release memory holding the relocated ELF image */
 
   if (loadinfo->alloc)
     {
@@ -85,19 +91,6 @@ int elf_unload(struct elf_loadinfo_s *loadinfo)
       loadinfo->allocsize = 0;
     }
 
-  if (loadinfo->shdr)
-    {
-      kfree((FAR void *)loadinfo->shdr);
-      loadinfo->shdr      = NULL;
-    }
-
-  if (loadinfo->iobuffer)
-    {
-      kfree((FAR void *)loadinfo->iobuffer);
-      loadinfo->iobuffer  = NULL;
-      loadinfo->buflen    = 0;
-    }
-
   return OK;
 }