From: Mark Wielaard <mark@klomp.org>
Date: Wed, 10 Jun 2020 18:55:58 +0000 (+0200)
Subject: libebl: Remove Ebl struct size check and MODVERSION string.
X-Git-Tag: elfutils-0.180~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=27a388bdd21e6bc1a27f111b803b7903b8851606;p=thirdparty%2Felfutils.git

libebl: Remove Ebl struct size check and MODVERSION string.

We used to do several sanity checks when the ebl backend libraries
were loaded to make sure there was no version mismatch. When initializing
the backend we passed the current Ebl struct size so the library could
check it supported the given Ebl struct and we checked that the init
method returned the correct build time module version string. Neither
are necessary now that the backends are builtin.

Remove both the struct size check and the MODVERSION string (which
wasn't actually checked anymore). Make the init function return the
given Ebl handle or NULL on error (no init function currently indicates
any error).

Signed-off-by: Mark Wielaard <mark@klomp.org>
---

diff --git a/ChangeLog b/ChangeLog
index 854568e0b..c08af9d52 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2020-06-10  Mark Wielaard  <mark@klomp.org>
+
+	* configure.ac (MODVERSION): Remove.
+
 2020-03-30  Mark Wielaard  <mark@klomp.org>
 
 	* configure.ac: Set version to 0.179.
diff --git a/backends/ChangeLog b/backends/ChangeLog
index 3f5f9bb02..7d3578b03 100644
--- a/backends/ChangeLog
+++ b/backends/ChangeLog
@@ -1,3 +1,23 @@
+2020-06-10  Mark Wielard  <mark@klomp.org>
+
+	* aarch64_init.c (aarch64_init): Remove ehlen, return eh.
+	* alpha_init.c (alpha_init): Likewise.
+	* arm_init.c (arm_init): Likewise.
+	* bpf_init.c (bpf_init): Likewise.
+	* csky_init.c (csky_init): Likewise.
+	* i386_init.c (i386_init): Likewise.
+	* ia64_init.c (ia64_init): Likewise.
+	* m68k_init.c (m68k_init): Likewise.
+	* ppc64_init.c (ppc64_init): Likewise.
+	* ppc_init.c (ppc_init): Likewise.
+	* riscv_init.c (riscv_init): Likewise.
+	* s390_init.c (s390_init): Likewise.
+	* sh_init.c (sh_init): Likewise.
+	* sparc_init.c (sparc_init): Likewise.
+	* tilegx_init.c (tilegx_init): Likewise.
+	* x86_64_init.c (x86_64_init): Likewise.
+	* libebl_CPU.h (init): Adjust EBLHOOK signature.
+
 2019-07-05  Omar Sandoval  <osandov@fb.com>
 
 	* Makefile.am: Replace libcpu_{i386,x86_64,bpf}.a with libcpu.a.
diff --git a/backends/aarch64_init.c b/backends/aarch64_init.c
index 95268ae03..66bfae942 100644
--- a/backends/aarch64_init.c
+++ b/backends/aarch64_init.c
@@ -38,16 +38,11 @@
 #include "common-reloc.c"
 
 
-const char *
+Ebl *
 aarch64_init (Elf *elf __attribute__ ((unused)),
 	      GElf_Half machine __attribute__ ((unused)),
-	      Ebl *eh,
-	      size_t ehlen)
+	      Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   aarch64_init_reloc (eh);
   HOOK (eh, register_info);
@@ -65,5 +60,5 @@ aarch64_init (Elf *elf __attribute__ ((unused)),
   HOOK (eh, set_initial_registers_tid);
   HOOK (eh, unwind);
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/alpha_init.c b/backends/alpha_init.c
index f66f40c51..c69aec6d4 100644
--- a/backends/alpha_init.c
+++ b/backends/alpha_init.c
@@ -39,16 +39,11 @@
 #include "common-reloc.c"
 
 
-const char *
+Ebl *
 alpha_init (Elf *elf __attribute__ ((unused)),
 	    GElf_Half machine __attribute__ ((unused)),
-	    Ebl *eh,
-	    size_t ehlen)
+	    Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   alpha_init_reloc (eh);
   HOOK (eh, dynamic_tag_name);
@@ -64,5 +59,5 @@ alpha_init (Elf *elf __attribute__ ((unused)),
   HOOK (eh, auxv_info);
   eh->sysvhash_entrysize = sizeof (Elf64_Xword);
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/arm_init.c b/backends/arm_init.c
index af023f02e..edd53b753 100644
--- a/backends/arm_init.c
+++ b/backends/arm_init.c
@@ -39,16 +39,11 @@
 #include "common-reloc.c"
 
 
-const char *
+Ebl *
 arm_init (Elf *elf __attribute__ ((unused)),
 	  GElf_Half machine __attribute__ ((unused)),
-	  Ebl *eh,
-	  size_t ehlen)
+	  Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   arm_init_reloc (eh);
   HOOK (eh, segment_type_name);
@@ -72,5 +67,5 @@ arm_init (Elf *elf __attribute__ ((unused)),
   /* Bit zero encodes whether an function address is THUMB or ARM. */
   eh->func_addr_mask = ~(GElf_Addr)1;
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/bpf_init.c b/backends/bpf_init.c
index d407d378b..f20f339e3 100644
--- a/backends/bpf_init.c
+++ b/backends/bpf_init.c
@@ -39,20 +39,16 @@
 #include "common-reloc.c"
 
 
-const char *
+Ebl *
 bpf_init (Elf *elf __attribute__ ((unused)),
 	  GElf_Half machine __attribute__ ((unused)),
-	  Ebl *eh, size_t ehlen)
+	  Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   bpf_init_reloc (eh);
   HOOK (eh, register_info);
   HOOK (eh, disasm);
   HOOK (eh, reloc_simple_type);
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/csky_init.c b/backends/csky_init.c
index b34a03aa3..b2863ced8 100644
--- a/backends/csky_init.c
+++ b/backends/csky_init.c
@@ -37,16 +37,11 @@
 /* This defines the common reloc hooks based on csky_reloc.def.  */
 #include "common-reloc.c"
 
-const char *
+Ebl *
 csky_init (Elf *elf __attribute__ ((unused)),
 	   GElf_Half machine __attribute__ ((unused)),
-	   Ebl *eh,
-	   size_t ehlen)
+	   Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   csky_init_reloc (eh);
   HOOK (eh, abi_cfi);
@@ -61,5 +56,5 @@ csky_init (Elf *elf __attribute__ ((unused)),
   /* gcc/config/ #define DWARF_FRAME_REGISTERS.  */
   eh->frame_nregs = 38;
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/i386_init.c b/backends/i386_init.c
index 67428b537..3f6b9ed19 100644
--- a/backends/i386_init.c
+++ b/backends/i386_init.c
@@ -38,16 +38,11 @@
 /* This defines the common reloc hooks based on i386_reloc.def.  */
 #include "common-reloc.c"
 
-const char *
+Ebl *
 i386_init (Elf *elf __attribute__ ((unused)),
 	   GElf_Half machine __attribute__ ((unused)),
-	   Ebl *eh,
-	   size_t ehlen)
+	   Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   i386_init_reloc (eh);
   HOOK (eh, reloc_simple_type);
@@ -66,5 +61,5 @@ i386_init (Elf *elf __attribute__ ((unused)),
   HOOK (eh, set_initial_registers_tid);
   HOOK (eh, unwind);
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/ia64_init.c b/backends/ia64_init.c
index 2d1f43f21..b46b35ccb 100644
--- a/backends/ia64_init.c
+++ b/backends/ia64_init.c
@@ -38,16 +38,11 @@
 /* This defines the common reloc hooks based on ia64_reloc.def.  */
 #include "common-reloc.c"
 
-const char *
+Ebl *
 ia64_init (Elf *elf __attribute__ ((unused)),
 	   GElf_Half machine __attribute__ ((unused)),
-	   Ebl *eh,
-	   size_t ehlen)
+	   Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   ia64_init_reloc (eh);
   HOOK (eh, reloc_simple_type);
@@ -61,5 +56,5 @@ ia64_init (Elf *elf __attribute__ ((unused)),
   HOOK (eh, return_value_location);
   HOOK (eh, check_reloc_target_type);
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/libebl_CPU.h b/backends/libebl_CPU.h
index ef2b922b9..0e507bd39 100644
--- a/backends/libebl_CPU.h
+++ b/backends/libebl_CPU.h
@@ -37,8 +37,7 @@
 #define EBLHOOK_2(a, b)	a##b
 
 /* Constructor.  */
-extern const char *EBLHOOK(init) (Elf *elf, GElf_Half machine,
-				  Ebl *eh, size_t ehlen);
+extern Ebl *EBLHOOK(init) (Elf *elf, GElf_Half machine, Ebl *eh);
 
 #include "ebl-hooks.h"
 
diff --git a/backends/m68k_init.c b/backends/m68k_init.c
index 05d544c10..7b94f23af 100644
--- a/backends/m68k_init.c
+++ b/backends/m68k_init.c
@@ -37,16 +37,11 @@
 #include "common-reloc.c"
 
 
-const char *
+Ebl *
 m68k_init (Elf *elf __attribute__ ((unused)),
 	   GElf_Half machine __attribute__ ((unused)),
-	   Ebl *eh,
-	   size_t ehlen)
+	   Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   m68k_init_reloc (eh);
   HOOK (eh, gotpc_reloc_check);
@@ -59,5 +54,5 @@ m68k_init (Elf *elf __attribute__ ((unused)),
   eh->frame_nregs = 25;
   HOOK (eh, set_initial_registers_tid);
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/ppc64_init.c b/backends/ppc64_init.c
index c2e7043bc..f509aef62 100644
--- a/backends/ppc64_init.c
+++ b/backends/ppc64_init.c
@@ -41,16 +41,11 @@
 #include "common-reloc.c"
 
 
-const char *
+Ebl *
 ppc64_init (Elf *elf __attribute__ ((unused)),
 	    GElf_Half machine __attribute__ ((unused)),
-	    Ebl *eh,
-	    size_t ehlen)
+	    Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   ppc64_init_reloc (eh);
   HOOK (eh, reloc_simple_type);
@@ -107,5 +102,5 @@ ppc64_init (Elf *elf __attribute__ ((unused)),
 	}
     }
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/ppc_init.c b/backends/ppc_init.c
index eb286c256..ac440ab21 100644
--- a/backends/ppc_init.c
+++ b/backends/ppc_init.c
@@ -39,16 +39,11 @@
 #include "common-reloc.c"
 
 
-const char *
+Ebl *
 ppc_init (Elf *elf __attribute__ ((unused)),
 	  GElf_Half machine __attribute__ ((unused)),
-	  Ebl *eh,
-	  size_t ehlen)
+	  Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   ppc_init_reloc (eh);
   HOOK (eh, reloc_simple_type);
@@ -69,5 +64,5 @@ ppc_init (Elf *elf __attribute__ ((unused)),
   HOOK (eh, set_initial_registers_tid);
   HOOK (eh, dwarf_to_regno);
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/riscv_init.c b/backends/riscv_init.c
index 9be5c6f29..551e7bb6d 100644
--- a/backends/riscv_init.c
+++ b/backends/riscv_init.c
@@ -43,16 +43,11 @@ extern __typeof (EBLHOOK (return_value_location))
 
 extern __typeof (EBLHOOK (core_note)) riscv64_core_note attribute_hidden;
 
-const char *
+Ebl *
 riscv_init (Elf *elf,
 	    GElf_Half machine __attribute__ ((unused)),
-	    Ebl *eh,
-	    size_t ehlen)
+	    Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   riscv_init_reloc (eh);
   HOOK (eh, reloc_simple_type);
@@ -73,5 +68,5 @@ riscv_init (Elf *elf,
 	  == EF_RISCV_FLOAT_ABI_DOUBLE))
     eh->return_value_location = riscv_return_value_location_lp64d;
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/s390_init.c b/backends/s390_init.c
index b4f3e7f88..fd79502d8 100644
--- a/backends/s390_init.c
+++ b/backends/s390_init.c
@@ -40,16 +40,11 @@
 extern __typeof (s390_core_note) s390x_core_note;
 
 
-const char *
+Ebl *
 s390_init (Elf *elf __attribute__ ((unused)),
 	   GElf_Half machine __attribute__ ((unused)),
-	   Ebl *eh,
-	   size_t ehlen)
+	   Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   s390_init_reloc (eh);
   HOOK (eh, reloc_simple_type);
@@ -75,5 +70,5 @@ s390_init (Elf *elf __attribute__ ((unused)),
   if (eh->class == ELFCLASS64)
     eh->sysvhash_entrysize = sizeof (Elf64_Xword);
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/sh_init.c b/backends/sh_init.c
index 24f4d4a4b..05cf8b180 100644
--- a/backends/sh_init.c
+++ b/backends/sh_init.c
@@ -39,16 +39,11 @@
 #include "common-reloc.c"
 
 
-const char *
+Ebl *
 sh_init (Elf *elf __attribute__ ((unused)),
 	 GElf_Half machine __attribute__ ((unused)),
-	 Ebl *eh,
-	 size_t ehlen)
+	 Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   sh_init_reloc (eh);
   HOOK (eh, reloc_simple_type);
@@ -58,5 +53,5 @@ sh_init (Elf *elf __attribute__ ((unused)),
   HOOK (eh, register_info);
   HOOK (eh, return_value_location);
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/sparc_init.c b/backends/sparc_init.c
index 6daff114a..647a7897d 100644
--- a/backends/sparc_init.c
+++ b/backends/sparc_init.c
@@ -44,16 +44,11 @@
 
 extern __typeof (EBLHOOK (core_note)) sparc64_core_note attribute_hidden;
 
-const char *
+Ebl *
 sparc_init (Elf *elf __attribute__ ((unused)),
 	    GElf_Half machine __attribute__ ((unused)),
-	    Ebl *eh,
-	    size_t ehlen)
+	    Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   sparc_init_reloc (eh);
   HOOK (eh, reloc_simple_type);
@@ -79,5 +74,5 @@ sparc_init (Elf *elf __attribute__ ((unused)),
   eh->ra_offset = 8;
   HOOK (eh, set_initial_registers_tid);
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/tilegx_init.c b/backends/tilegx_init.c
index 66df9318a..0f79542af 100644
--- a/backends/tilegx_init.c
+++ b/backends/tilegx_init.c
@@ -37,16 +37,11 @@
 /* This defines the common reloc hooks based on tilegx_reloc.def.  */
 #include "common-reloc.c"
 
-const char *
+Ebl *
 tilegx_init (Elf *elf __attribute__ ((unused)),
 	     GElf_Half machine __attribute__ ((unused)),
-	     Ebl *eh,
-	     size_t ehlen)
+	     Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   tilegx_init_reloc (eh);
   HOOK (eh, reloc_simple_type);
@@ -54,5 +49,5 @@ tilegx_init (Elf *elf __attribute__ ((unused)),
   HOOK (eh, register_info);
   HOOK (eh, core_note);
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/backends/x86_64_init.c b/backends/x86_64_init.c
index 8abafb7f1..44c1ad288 100644
--- a/backends/x86_64_init.c
+++ b/backends/x86_64_init.c
@@ -41,16 +41,11 @@
 
 extern __typeof (EBLHOOK (core_note)) x32_core_note attribute_hidden;
 
-const char *
+Ebl *
 x86_64_init (Elf *elf __attribute__ ((unused)),
 	     GElf_Half machine __attribute__ ((unused)),
-	     Ebl *eh,
-	     size_t ehlen)
+	     Ebl *eh)
 {
-  /* Check whether the Elf_BH object has a sufficent size.  */
-  if (ehlen < sizeof (Ebl))
-    return NULL;
-
   /* We handle it.  */
   x86_64_init_reloc (eh);
   HOOK (eh, reloc_simple_type);
@@ -70,5 +65,5 @@ x86_64_init (Elf *elf __attribute__ ((unused)),
   HOOK (eh, set_initial_registers_tid);
   HOOK (eh, unwind);
 
-  return MODVERSION;
+  return eh;
 }
diff --git a/configure.ac b/configure.ac
index a39e800f7..c2c6890a1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -627,12 +627,6 @@ esac
 # Round up to the next release API (x.y) version.
 eu_version=$(( (eu_version + 999) / 1000 ))
 
-dnl Unique ID for this build.
-MODVERSION="Build for ${eu_version} ${ac_cv_build}"
-AC_SUBST([MODVERSION])
-AC_DEFINE_UNQUOTED(MODVERSION, "$MODVERSION")
-AH_TEMPLATE([MODVERSION], [Identifier for modules in the build.])
-
 AC_CHECK_SIZEOF(long)
 
 # On aarch64 before glibc 2.20 we would get the kernel user_pt_regs instead
diff --git a/libebl/ChangeLog b/libebl/ChangeLog
index 75aa1ab84..fa6dd0373 100644
--- a/libebl/ChangeLog
+++ b/libebl/ChangeLog
@@ -1,3 +1,12 @@
+2020-06-10  Mark Wielaard  <mark@klomp.org>
+
+	* eblopenbackend.c (i386_init, sh_init, x86_64_init, ia64_init,
+	alpha_init, arm_init, aarch64_init, sparc_init, ppc_init,
+	ppc64_init, s390_init, tilegx_init, m68k_init, bpf_init,
+	riscv_init, csky_init): Adjust signature.
+	(openbackend): Call init without sizeof(Ebl).
+	* libeblP.h (ebl_bhinit_t): Adjust signature.
+
 2020-06-04  Mark Wielaard  <mark@klomp.org>
 
 	* eblsegmenttypename.c (ebl_segment_type_name): Remove
diff --git a/libebl/eblopenbackend.c b/libebl/eblopenbackend.c
index 4ebde45f2..b3b6fc01a 100644
--- a/libebl/eblopenbackend.c
+++ b/libebl/eblopenbackend.c
@@ -41,22 +41,22 @@
 #include <system.h>
 #include <libeblP.h>
 
-const char *i386_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *sh_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *x86_64_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *ia64_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *alpha_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *arm_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *aarch64_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *sparc_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *ppc_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *ppc64_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *s390_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *tilegx_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *m68k_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *bpf_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *riscv_init (Elf *, GElf_Half, Ebl *, size_t);
-const char *csky_init (Elf *, GElf_Half, Ebl *, size_t);
+Ebl *i386_init (Elf *, GElf_Half, Ebl *);
+Ebl *sh_init (Elf *, GElf_Half, Ebl *);
+Ebl *x86_64_init (Elf *, GElf_Half, Ebl *);
+Ebl *ia64_init (Elf *, GElf_Half, Ebl *);
+Ebl *alpha_init (Elf *, GElf_Half, Ebl *);
+Ebl *arm_init (Elf *, GElf_Half, Ebl *);
+Ebl *aarch64_init (Elf *, GElf_Half, Ebl *);
+Ebl *sparc_init (Elf *, GElf_Half, Ebl *);
+Ebl *ppc_init (Elf *, GElf_Half, Ebl *);
+Ebl *ppc64_init (Elf *, GElf_Half, Ebl *);
+Ebl *s390_init (Elf *, GElf_Half, Ebl *);
+Ebl *tilegx_init (Elf *, GElf_Half, Ebl *);
+Ebl *m68k_init (Elf *, GElf_Half, Ebl *);
+Ebl *bpf_init (Elf *, GElf_Half, Ebl *);
+Ebl *riscv_init (Elf *, GElf_Half, Ebl *);
+Ebl *csky_init (Elf *, GElf_Half, Ebl *);
 
 /* This table should contain the complete list of architectures as far
    as the ELF specification is concerned.  */
@@ -330,7 +330,7 @@ openbackend (Elf *elf, const char *emulation, GElf_Half machine)
 	  }
 
         if (machines[cnt].init &&
-            machines[cnt].init (elf, machine, result, sizeof(Ebl)))
+            machines[cnt].init (elf, machine, result))
           {
             result->elf = elf;
             /* A few entries are mandatory.  */
diff --git a/libebl/libeblP.h b/libebl/libeblP.h
index fd0fcc98a..599f6378a 100644
--- a/libebl/libeblP.h
+++ b/libebl/libeblP.h
@@ -80,8 +80,10 @@ struct ebl
 };
 
 
-/* Type of the initialization functions in the backend modules.  */
-typedef const char *(*ebl_bhinit_t) (Elf *, GElf_Half, Ebl *, size_t);
+/* Type of the initialization functions in the backend modules.
+   The init function returns the given Ebl * or NULL if it couldn't
+   initialize for the given Elf or machine.  */
+typedef Ebl *(*ebl_bhinit_t) (Elf *, GElf_Half, Ebl *);
 
 
 /* gettext helper macros.  */