Patch (output of diff -u) to bfd/elfcode.h so that programs such as

gdb, size, objdump will work with UPX-packed executables. committer: jreiser <jreiser> 958752295 +0000
2025-02-17 06:38:06 +00:00 · 2000-05-19 16:04:55 +00:00 · 2000-05-19 16:04:55 +00:00 · e6e9229942
commit e6e9229942
parent 1a9128a473
1 changed files with 98 additions and 0 deletions
--- a/src/stub/patch-elfcode.h
+++ b/src/stub/patch-elfcode.h
@ -0,0 +1,98 @@
+The GNU bfd binary file descriptor package, part of the GNU binutils package,
+contains code to recognize an Elf file by looking at fields in the file header.
+Many programs (such as gdb, size, objdump, objcopy, strip and others) use bfd.
+Unfortunately, bfd has been overly strict.  In releases binutils-2.9.1.0.4,
+binutils-2.9.1.0.23, binutils-2.9.5.0.0, gdb-4.17, and probably others,
+bfd does not recognize a file with zero in Elf32_Ehdr.e_shoff, .e_shentsize,
+or .e_shnum, even though the operating system kernel does not care, and many
+bfd clients would work just fine in these cases.
+
+Because of its desire to create small size compressed executables, UPX
+generates and uses Elf files with zero in .e_shoff, .e_shentsizes, and .e_shnum.
+As a result, many widely-distributed instances of gdb, size, objdump, etc.,
+refuse to work on UPX-packed executables.
+
+Here is a patch to bfd/elfcode.h which enables many bfd clients to work
+with UPX-packed executables.  The last two lines of the patch are
+       if (bfd_seek (abfd, hdr->sh_offset, SEEK_SET) == -1)
+ 	return -1;
+
+
+--- elfcode.h.orig	Mon Jun 16 11:45:32 1997
+++ elfcode.h	Sat Apr 22 10:18:56 2000
+@@ -1,5 +1,5 @@
+ /* ELF executable support for BFD.
+-   Copyright 1991, 92, 93, 94, 95, 96, 1997 Free Software Foundation, Inc.
+   Copyright 1991, 92, 93, 94, 95, 96, 97, 1998 Free Software Foundation, Inc.
+ 
+    Written by Fred Fish @ Cygnus Support, from information published
+    in "UNIX System V Release 4, Programmers Guide: ANSI C and
+@@ -517,14 +517,14 @@
+   elf_debug_file (i_ehdrp);
+ #endif
+ 
+-  /* If there is no section header table, we're hosed. */
+-  if (i_ehdrp->e_shoff == 0)
+  /* If there is no section header table, and relocatable, then we're hosed. */
+  if (i_ehdrp->e_shoff == 0 && i_ehdrp->e_type == ET_REL)
+     goto got_wrong_format_error;
+ 
+   /* As a simple sanity check, verify that the what BFD thinks is the
+      size of each section header table entry actually matches the size
+-     recorded in the file. */
+-  if (i_ehdrp->e_shentsize != sizeof (x_shdr))
+     recorded in the file, but only if there are any sections. */
+  if (i_ehdrp->e_shentsize != sizeof (x_shdr) &&  i_ehdrp->e_shnum != 0)
+     goto got_wrong_format_error;
+ 
+   ebd = get_elf_backend_data (abfd);
+@@ -579,6 +579,7 @@
+   /* Allocate space for a copy of the section header table in
+      internal form, seek to the section header table in the file,
+      read it in, and convert it to internal form.  */
+ if (i_ehdrp->e_shnum!=0) {
+   i_shdrp = ((Elf_Internal_Shdr *)
+ 	     bfd_alloc (abfd, sizeof (*i_shdrp) * i_ehdrp->e_shnum));
+   elf_elfsections (abfd) = ((Elf_Internal_Shdr **)
+@@ -609,6 +610,7 @@
+       if (! bfd_section_from_shdr (abfd, i_ehdrp->e_shstrndx))
+ 	goto got_no_match;
+     }
+ }
+ 
+   /* Read in the program headers.  */
+   if (i_ehdrp->e_phnum == 0)
+@@ -644,6 +646,7 @@
+      bfd_section_from_shdr with it (since this particular strtab is
+      used to find all of the ELF section names.) */
+ 
+ if (i_ehdrp->e_shstrndx != 0) {
+   shstrtab = bfd_elf_get_str_section (abfd, i_ehdrp->e_shstrndx);
+   if (!shstrtab)
+     goto got_no_match;
+@@ -657,6 +660,7 @@
+       if (! bfd_section_from_shdr (abfd, shindex))
+ 	goto got_no_match;
+     }
+ }
+ 
+   /* Let the backend double check the format and override global
+      information.  */
+@@ -930,7 +934,7 @@
+ {
+   Elf_Internal_Shdr *hdr;
+   Elf_Internal_Shdr *verhdr;
+-  long symcount;		/* Number of external ELF symbols */
+  unsigned long symcount;	/* Number of external ELF symbols */
+   elf_symbol_type *sym;		/* Pointer to current bfd symbol */
+   elf_symbol_type *symbase;	/* Buffer for generated bfd symbols */
+   Elf_Internal_Sym i_sym;
+@@ -978,7 +982,7 @@
+     sym = symbase = NULL;
+   else
+     {
+-      long i;
+      unsigned long i;
+ 
+       if (bfd_seek (abfd, hdr->sh_offset, SEEK_SET) == -1)
+ 	return -1;