Don't create INTERP and PHDR program header entry if a DSO is created without

a specific interpreter.

Ignore duplicate COMDAT group sections.

elflint should not complain about anything about *_NONE relocations.
Add support to libebl to determine whether given relocation is *_NONE
relocation.

6 files changed, 156 insertions, 60 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 74ea2bfa..c7c113e4 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,25 @@
+2006-06-12  Ulrich Drepper  <[email protected]>
+
+	* ldgeneric.c (ld_generic_generate_sections): Don't create .interp
+	section if creating a DSO and no interpreter is given.
+	(ld_generic_create_outfile): Don't store reference to symbols in
+	discarded COMDAT groups.  Don't create PHDR and INTERP program header
+	for DSO if no interpreter is specified.
+	* ldscript.y (content): If a DSO is created don't set default
+	interpreter from linker script.
+
+	* i386_ld.c (elf_i386_count_relocations): Do not add relocations
+	for symbols in discarded COMDAT groups.
+	(elf_i386_create_relocations): Likewise.
+	* ld.h (struct scninfo): Add unused_comdat.
+	* ldgeneric.c (add_section): Also check group signature when
+	matching COMDAT sections.
+	(add_relocatable_file): Ignore symbols in COMDAT group which are
+	discarded.
+
+	* elflint.c (check_one_reloc): For *_NONE relocs only check type
+	and symbol reference.
+
 2006-06-11  Ulrich Drepper  <[email protected]>
 
 	* elflint.c (check_dynamic): Fix checking value of tags which are
diff --git a/src/elflint.c b/src/elflint.c
index b1eb5d3d..cd335fe6 100644
--- a/src/elflint.c
+++ b/src/elflint.c
@@ -1170,6 +1170,10 @@ section [%2d] '%s': relocation %zu: relocation type invalid for the file type\n"
 section [%2d] '%s': relocation %zu: invalid symbol index\n"),
 	   idx, section_name (ebl, idx), cnt);
 
+  /* No more tests if this is a no-op relocation.  */
+  if (ebl_none_reloc_p (ebl, GELF_R_TYPE (r_info)))
+    return;
+
   if (ebl_gotpc_reloc_check (ebl, GELF_R_TYPE (r_info)))
     {
       const char *name;
diff --git a/src/i386_ld.c b/src/i386_ld.c
index d1a213d6..a0c77dbe 100644
--- a/src/i386_ld.c
+++ b/src/i386_ld.c
@@ -525,6 +525,11 @@ elf_i386_count_relocations (struct ld_state *statep, struct scninfo *scninfo)
 	{
 	  Elf32_Word r_sym = XELF_R_SYM (rel->r_info);
 
+	  /* Symbols in COMDAT group sections which are discarded do
+	     not have to be relocated.  */
+	  if (unlikely (scninfo->fileinfo->symref[r_sym] == NULL))
+	    continue;
+
 	  switch (XELF_R_TYPE (rel->r_info))
 	    {
 	    case R_386_GOT32:
@@ -717,16 +722,24 @@ elf_i386_create_relocations (struct ld_state *statep,
 		 section in the output file and the addend.  */
 	      value = scninfo[sym->st_shndx].offset + sym->st_value;
 	    }
-	  else if (symref[idx]->in_dso)
+	  else
 	    {
-	      /* MERGE.VALUE contains the PLT index.  We have to add 1 since
-		 there is this one special PLT entry at the beginning.  */
-	      assert (symref[idx]->merge.value != 0
-		      || symref[idx]->type != STT_FUNC);
-	      value = pltaddr + symref[idx]->merge.value * PLT_ENTRY_SIZE;
+	      if (symref[idx] == NULL)
+		/* Symbol in ignored COMDAT group section.  */
+		continue;
+
+	      if (symref[idx]->in_dso)
+		{
+		  /* MERGE.VALUE contains the PLT index.  We have to
+		     add 1 since there is this one special PLT entry
+		     at the beginning.  */
+		  assert (symref[idx]->merge.value != 0
+			  || symref[idx]->type != STT_FUNC);
+		  value = pltaddr + symref[idx]->merge.value * PLT_ENTRY_SIZE;
+		}
+	      else
+		value = symref[idx]->merge.value;
 	    }
-	  else
-	    value = symref[idx]->merge.value;
 
 	  /* Address of the relocated memory in the data buffer.  */
 	  void *relloc = (char *) data->d_buf + rel->r_offset;
diff --git a/src/ld.h b/src/ld.h
index 36afca13..bdabee44 100644
--- a/src/ld.h
+++ b/src/ld.h
@@ -174,6 +174,8 @@ struct usedfiles
     Elf32_Word allsectionsidx;
     /* True if the section is used.  */
     bool used;
+    /* True if section is an unused COMDAT section.  */
+    bool unused_comdat;
     /* Section group number.  This is the index of the SHT_GROUP section.  */
     Elf32_Word grpid;
     /* Pointer back to the containing file information structure.  */
diff --git a/src/ldgeneric.c b/src/ldgeneric.c
index c089e0ba..22fac228 100644
--- a/src/ldgeneric.c
+++ b/src/ldgeneric.c
@@ -991,7 +991,36 @@ add_section (struct usedfiles *fileinfo, struct scninfo *scninfo)
 	    }
 
 	  /* XXX Possibly unaligned memory access.  */
-	  is_comdat = ((Elf32_Word *) grpscndata->d_buf)[0] & GRP_COMDAT;
+	  if ((((Elf32_Word *) grpscndata->d_buf)[0] & GRP_COMDAT) != 0)
+	    {
+	      /* We have to compare the group signatures.  There might
+		 be sections with the same name but belonging to
+		 groups with different signatures.  This means we have
+		 to compare the new group signature with all those
+		 already collected.  There might also be some
+		 non-group sections in the mix.  */
+	      struct scninfo *runp = queued->last;
+	      do
+		{
+		  if (SCNINFO_SHDR (runp->shdr).sh_flags & SHF_GROUP)
+		    {
+		      struct scninfo *grpscn2
+			= find_section_group (runp->fileinfo,
+					      elf_ndxscn (runp->scn),
+					      &grpscndata);
+		  
+		      if (strcmp (grpscn->symbols->name,
+				  grpscn2->symbols->name) == 0)
+			{
+			  scninfo->unused_comdat = is_comdat = true;
+			  break;
+			}
+		    }
+
+		  runp = runp->next;
+		}
+	      while (runp != queued->last);
+	    }
 	}
 
       if (!is_comdat)
@@ -1378,6 +1407,11 @@ add_relocatable_file (struct usedfiles *fileinfo, GElf_Word secttype)
 	  if (unlikely (shndx == SHN_ABS) && secttype == SHT_DYNSYM)
 	    continue;
 
+	  if ((shndx < SHN_LORESERVE || shndx > SHN_HIRESERVE)
+	      && fileinfo->scninfo[shndx].unused_comdat)
+	    /* The symbol is not used.  */
+	    continue;
+
 	  /* If the DSO uses symbols determine whether this is the default
 	     version.  Otherwise we'll ignore the symbol.  */
 	  if (versymdata != NULL)
@@ -2302,8 +2336,9 @@ ld_generic_generate_sections (struct ld_state *statep)
       bool need_version = false;
 
       /* First the .interp section.  */
-      new_generated_scn (scn_dot_interp, ".interp", SHT_PROGBITS, SHF_ALLOC,
-			 0, 1);
+      if (ld_state.interp != NULL || ld_state.file_type != dso_file_type)
+	new_generated_scn (scn_dot_interp, ".interp", SHT_PROGBITS, SHF_ALLOC,
+			   0, 1);
 
       /* Now the .dynamic section.  */
       new_generated_scn (scn_dot_dynamic, ".dynamic", SHT_DYNAMIC,
@@ -4739,23 +4774,24 @@ section index too large in dynamic symbol table"));
 	     Find the symbol if this has not happened yet.  We do
 	     not need the information for local symbols.  */
 	  if (defp == NULL && cnt >= file->nlocalsymbols)
-	    {
-	      defp = file->symref[cnt];
-	      assert (defp != NULL);
-	    }
+	    defp = file->symref[cnt];
 
-	  /* Store the reference to the symbol record.  The
-	     sorting code will have to keep this array in the
-	     correct order, too.  */
-	  ndxtosym[nsym] = defp;
-
-	  /* One more entry finished.  */
-	  if (cnt >= file->nlocalsymbols)
+	  /* Ignore symbols in discarded COMDAT group sections.  */
+	  if (defp != NULL)
 	    {
-	      assert (file->symref[cnt]->outsymidx == 0);
-	      file->symref[cnt]->outsymidx = nsym;
+	      /* Store the reference to the symbol record.  The
+		 sorting code will have to keep this array in the
+		 correct order, too.  */
+	      ndxtosym[nsym] = defp;
+
+	      /* One more entry finished.  */
+	      if (cnt >= file->nlocalsymbols)
+		{
+		  assert (file->symref[cnt]->outsymidx == 0);
+		  file->symref[cnt]->outsymidx = nsym;
+		}
+	      file->symindirect[cnt] = nsym++;
 	    }
-	  file->symindirect[cnt] = nsym++;
 	}
     }
   while ((file = file->next) != ld_state.relfiles->next);
@@ -5624,10 +5660,16 @@ cannot create hash table section for output file: %s"),
       /* Add the number of SHT_NOTE sections.  We counted them earlier.  */
       nphdr += ld_state.nnotesections;
 
-      /* If we create a DSO or the file is linked against DSOs we have three
-	 more entries: INTERP, PHDR, DYNAMIC.  */
+      /* If we create a DSO or the file is linked against DSOs we have
+	 at least one more entry: DYNAMIC.  If an interpreter is
+	 specified we add PHDR and INTERP, too.  */
       if (dynamically_linked_p ())
-	nphdr += 3;
+	{
+	  ++nphdr;
+
+	  if (ld_state.interp != NULL || ld_state.file_type != dso_file_type)
+	    nphdr += 2;
+	}
 
       /* Create the program header structure.  */
       if (xelf_newphdr (ld_state.outelf, nphdr) == 0)
@@ -5655,7 +5697,14 @@ cannot create hash table section for output file: %s"),
       addr = shdr->sh_offset;
 
       /* The index of the first loadable segment.  */
-      nphdr = 1 + (dynamically_linked_p () == true) * 2;
+      nphdr = 0;
+      if (dynamically_linked_p ())
+	{
+	  ++nphdr;
+	  if (ld_state.interp != NULL
+	      || ld_state.file_type != dso_file_type)
+	    nphdr += 2;
+	}
 
       segment = ld_state.output_segments;
       while (segment != NULL)
@@ -5813,18 +5862,6 @@ internal error: nobits section follows nobits section"));
       xelf_getehdr (ld_state.outelf, ehdr);
       assert (ehdr != NULL);
 
-      xelf_getphdr_ptr (ld_state.outelf, 0, phdr);
-      phdr->p_type = PT_PHDR;
-      phdr->p_offset = ehdr->e_phoff;
-      phdr->p_vaddr = ld_state.output_segments->addr + phdr->p_offset;
-      phdr->p_paddr = phdr->p_vaddr;
-      phdr->p_filesz = ehdr->e_phnum * ehdr->e_phentsize;
-      phdr->p_memsz = phdr->p_filesz;
-      phdr->p_flags = 0;		/* No need to set PF_R or so.  */
-      phdr->p_align = xelf_fsize (ld_state.outelf, ELF_T_ADDR, 1);
-      (void) xelf_update_phdr (ld_state.outelf, 0, phdr);
-
-
       /* Add the stack information.  */
       xelf_getphdr_ptr (ld_state.outelf, nphdr, phdr);
       phdr->p_type = PT_GNU_STACK;
@@ -5941,24 +5978,41 @@ internal error: nobits section follows nobits section"));
 	{
 	  Elf_Scn *outscn;
 
-	  assert (ld_state.interpscnidx != 0);
-	  xelf_getshdr (elf_getscn (ld_state.outelf, ld_state.interpscnidx),
-			shdr);
-	  assert (shdr != NULL);
+	  int idx = 0;
+	  if (ld_state.interp != NULL || ld_state.file_type != dso_file_type)
+	    {
+	      assert (ld_state.interpscnidx != 0);
+	      xelf_getshdr (elf_getscn (ld_state.outelf,
+					ld_state.interpscnidx), shdr);
+	      assert (shdr != NULL);
 
-	  /* The interpreter string.  */
-	  // XXX Do we need to support files (DSOs) without interpreters?
-	  xelf_getphdr_ptr (ld_state.outelf, 1, phdr);
-	  phdr->p_type = PT_INTERP;
-	  phdr->p_offset = shdr->sh_offset;
-	  phdr->p_vaddr = shdr->sh_addr;
-	  phdr->p_paddr = phdr->p_vaddr;
-	  phdr->p_filesz = shdr->sh_size;
-	  phdr->p_memsz = phdr->p_filesz;
-	  phdr->p_flags = 0;		/* No need to set PF_R or so.  */
-	  phdr->p_align = 1;		/* It's a string.  */
+	      xelf_getphdr_ptr (ld_state.outelf, idx, phdr);
+	      phdr->p_type = PT_PHDR;
+	      phdr->p_offset = ehdr->e_phoff;
+	      phdr->p_vaddr = ld_state.output_segments->addr + phdr->p_offset;
+	      phdr->p_paddr = phdr->p_vaddr;
+	      phdr->p_filesz = ehdr->e_phnum * ehdr->e_phentsize;
+	      phdr->p_memsz = phdr->p_filesz;
+	      phdr->p_flags = 0;	/* No need to set PF_R or so.  */
+	      phdr->p_align = xelf_fsize (ld_state.outelf, ELF_T_ADDR, 1);
+
+	      (void) xelf_update_phdr (ld_state.outelf, idx, phdr);
+	      ++idx;
+
+	      /* The interpreter string.  */
+	      xelf_getphdr_ptr (ld_state.outelf, idx, phdr);
+	      phdr->p_type = PT_INTERP;
+	      phdr->p_offset = shdr->sh_offset;
+	      phdr->p_vaddr = shdr->sh_addr;
+	      phdr->p_paddr = phdr->p_vaddr;
+	      phdr->p_filesz = shdr->sh_size;
+	      phdr->p_memsz = phdr->p_filesz;
+	      phdr->p_flags = 0;	/* No need to set PF_R or so.  */
+	      phdr->p_align = 1;	/* It's a string.  */
 
-	  (void) xelf_update_phdr (ld_state.outelf, 1, phdr);
+	      (void) xelf_update_phdr (ld_state.outelf, idx, phdr);
+	      ++idx;
+	    }
 
 	  /* The pointer to the dynamic section.  We this we need to
 	     get the information for the dynamic section first.  */
@@ -5967,7 +6021,7 @@ internal error: nobits section follows nobits section"));
 	  xelf_getshdr (outscn, shdr);
 	  assert (shdr != NULL);
 
-	  xelf_getphdr_ptr (ld_state.outelf, 2, phdr);
+	  xelf_getphdr_ptr (ld_state.outelf, idx, phdr);
 	  phdr->p_type = PT_DYNAMIC;
 	  phdr->p_offset = shdr->sh_offset;
 	  phdr->p_vaddr = shdr->sh_addr;
@@ -5977,7 +6031,7 @@ internal error: nobits section follows nobits section"));
 	  phdr->p_flags = 0;		/* No need to set PF_R or so.  */
 	  phdr->p_align = shdr->sh_addralign;
 
-	  (void) xelf_update_phdr (ld_state.outelf, 2, phdr);
+	  (void) xelf_update_phdr (ld_state.outelf, idx, phdr);
 
 	  /* Fill in the reference to the .dynstr section.  */
 	  assert (ld_state.dynstrscnidx != 0);
diff --git a/src/ldscript.y b/src/ldscript.y
index 764b4157..252f9d4b 100644
--- a/src/ldscript.y
+++ b/src/ldscript.y
@@ -165,7 +165,8 @@ content:	  kENTRY '(' kID ')' ';'
 		    }
 		| kINTERP '(' filename_id ')' ';'
 		    {
-		      if (likely (ld_state.interp == NULL))
+		      if (likely (ld_state.interp == NULL)
+			  && ld_state.file_type != dso_file_type)
 			ld_state.interp = $3;
 		    }
 		| kSEGMENT kMODE '{' outputsections '}'