From: Roland McGrath <roland@redhat.com>
Date: Tue, 10 Nov 2009 21:34:09 +0000 (-0800)
Subject: __libelf_readall: Fetch file size if not yet known.
X-Git-Tag: elfutils-0.144~27
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0c6db7e36967e56cb3245e145c441e83d23cc4d4;p=thirdparty%2Felfutils.git

__libelf_readall: Fetch file size if not yet known.
---

diff --git a/libelf/ChangeLog b/libelf/ChangeLog
index 974afa157..8098f4e95 100644
--- a/libelf/ChangeLog
+++ b/libelf/ChangeLog
@@ -1,3 +1,7 @@
+2009-11-10  Roland McGrath  <roland@redhat.com>
+
+	* elf_readall.c (__libelf_readall): Fetch file size if not yet known.
+
 2009-11-06  Mark Wielaard  <mjw@redhat.com>
 
 	* elf_next.c (elf_next): Mark the archive header as unusable when
diff --git a/libelf/elf_readall.c b/libelf/elf_readall.c
index 8f171b21c..1f59932f1 100644
--- a/libelf/elf_readall.c
+++ b/libelf/elf_readall.c
@@ -1,5 +1,5 @@
 /* Read all of the file associated with the descriptor.
-   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2005 Red Hat, Inc.
+   Copyright (C) 1998-2009 Red Hat, Inc.
    This file is part of Red Hat elfutils.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 1998.
 
@@ -54,6 +54,7 @@
 
 #include <errno.h>
 #include <unistd.h>
+#include <sys/stat.h>
 
 #include <system.h>
 #include "libelfP.h"
@@ -102,12 +103,30 @@ __libelf_readall (elf)
   /* If the file is not mmap'ed and not previously loaded, do it now.  */
   if (elf->map_address == NULL)
     {
-      char *mem;
+      char *mem = NULL;
 
       /* If this is an archive and we have derived descriptors get the
 	 locks for all of them.  */
       libelf_acquire_all (elf);
 
+      if (elf->maximum_size == ~((size_t) 0))
+	{
+	  /* We don't yet know how large the file is.   Determine that now.  */
+	  struct stat st;
+
+	  if (fstat (elf->fildes, &st) < 0)
+	    goto read_error;
+
+	  if (sizeof (size_t) >= sizeof (st.st_size)
+	      || st.st_size <= ~((size_t) 0))
+	    elf->maximum_size = (size_t) st.st_size;
+	  else
+	    {
+	      errno = EOVERFLOW;
+	      goto read_error;
+	    }
+	}
+
       /* Allocate all the memory we need.  */
       mem = (char *) malloc (elf->maximum_size);
       if (mem != NULL)
@@ -119,6 +138,7 @@ __libelf_readall (elf)
 			!= elf->maximum_size))
 	    {
 	      /* Something went wrong.  */
+	    read_error:
 	      __libelf_seterrno (ELF_E_READ_ERROR);
 	      free (mem);
 	    }