SHF_GNU_MBIND requires ELFOSABI_GNU

When SHF_GNU_MBIND was added in the SHF_LOOS to SHF_HIOS range, it
should have required ELFOSABI_GNU since these flags are already in use
by other OSes.  HPUX SHF_HP_TLS in fact has the same value.  That
means no place in binutils should test SHF_GNU_MBIND without first
checking OSABI, and SHF_GNU_MBIND should not be set without also
setting OSABI.  At least, that's the ideal, but the patch accepts
SHF_GNU_MBIND on ELFOSABI_NONE object files since gas didn't always
set OSABI.  However, to reinforce the fact that SHF_GNU_MBIND isn't
proper without a non-zero OSABI, readelf will display the flag as
LOOS+0 if OSABI isn't set.

The clash with SHF_HP_TLS means that hppa64-linux either has that flag
on .tbss sections or supports GNU_MBIND, not both.  (hppa64-linux
users, if there are any, may have noticed that GNU ld since 2017
mysteriously aligned their .tbss sections to a 4k boundary.  That was
one consequence of SHF_HP_TLS being blindly interpreted as
SHF_GNU_MBIND.)  Since it seems that binutils, gdb, gcc, glibc, and
the linux kernel don't care about SHF_HP_TLS I took that flag out of
.tbss for hppa64-linux.

bfd/
	* elf-bfd.h (enum elf_gnu_osabi): Add elf_gnu_osabi_mbind.
	* elf.c (_bfd_elf_make_section_from_shdr): Set elf_gnu_osabi_mbind.
	(get_program_header_size): Formatting.  Only test SH_GNU_MBIND
	when elf_gnu_osabi_mbind is set.
	(_bfd_elf_map_sections_to_segments): Likewise.
	(_bfd_elf_init_private_section_data): Likewise.
	(_bfd_elf_final_write_processing): Update comment.
	* elf64-hppa.c (elf64_hppa_special_sections): Move .tbss entry.
	(elf_backend_special_sections): Define without .tbss for linux.
binutils/
	* readelf.c (get_parisc_segment_type): Split off hpux entries..
	(get_ia64_segment_type): ..and these..
	(get_hpux_segment_type): ..to here.
	(get_segment_type): Condition GNU_MBIND on osabi.  Use
	get_hpux_segment_type.
	(get_symbol_binding): Do not print UNIQUE for ELFOSABI_NONE.
	(get_symbol_type): Do not print IFUNC for ELFOSABI_NONE.
gas/
	* config/obj-elf.c (obj_elf_change_section): Don't emit a fatal
	error for non-SHF_ALLOC SHF_GNU_MBIND here.
	(obj_elf_parse_section_letters): Return SHF_GNU_MBIND in new
	gnu_attr param.
	(obj_elf_section): Adjust obj_elf_parse_section_letters call.
	Formatting.  Set SHF_GNU_MBIND and elf_osabi from gnu_attr.
	Emit normal error for non-SHF_ALLOC SHF_GNU_MBIND and wrong osabi.
	(obj_elf_type): Set elf_osabi for ifunc.
	* testsuite/gas/elf/section12a.d: xfail msp430 and hpux.
	* testsuite/gas/elf/section12b.d: Likewise.
	* testsuite/gas/elf/section13.d: Likewise.
	* testsuite/gas/elf/section13.l: Adjust expected error.
ld/
	* emultempl/elf32.em (gld${EMULATION_NAME}_place_orphan): Condition
	SHF_GNU_MBIND on osabi.  Set output elf_gnu_osabi_mbind.

6 files changed, 65 insertions, 29 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 47938f7..19ca464 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,5 +1,20 @@
 2019-07-23  Alan Modra  <amodra@gmail.com>
 
+	* config/obj-elf.c (obj_elf_change_section): Don't emit a fatal
+	error for non-SHF_ALLOC SHF_GNU_MBIND here.
+	(obj_elf_parse_section_letters): Return SHF_GNU_MBIND in new
+	gnu_attr param.
+	(obj_elf_section): Adjust obj_elf_parse_section_letters call.
+	Formatting.  Set SHF_GNU_MBIND and elf_osabi from gnu_attr.
+	Emit normal error for non-SHF_ALLOC SHF_GNU_MBIND and wrong osabi.
+	(obj_elf_type): Set elf_osabi for ifunc.
+	* testsuite/gas/elf/section12a.d: xfail msp430 and hpux.
+	* testsuite/gas/elf/section12b.d: Likewise.
+	* testsuite/gas/elf/section13.d: Likewise.
+	* testsuite/gas/elf/section13.l: Adjust expected error.
+
+2019-07-23  Alan Modra  <amodra@gmail.com>
+
 	* testsuite/gas/elf/section12a.d: Don't skip for rx.
 
 2019-07-22  Barnaby Wilks  <barnaby.wilks@arm.com>
diff --git a/gas/config/obj-elf.c b/gas/config/obj-elf.c
index af35fee..fd2c943 100644
--- a/gas/config/obj-elf.c
+++ b/gas/config/obj-elf.c
@@ -706,9 +706,6 @@ obj_elf_change_section (const char *name,
 	attr |= ssect->attr;
     }
 
-  if ((attr & (SHF_ALLOC | SHF_GNU_MBIND)) == SHF_GNU_MBIND)
-    as_fatal (_("SHF_ALLOC isn't set for GNU_MBIND section: %s"), name);
-
   /* Convert ELF type and flags to BFD flags.  */
   flags = (SEC_RELOC
 	   | ((attr & SHF_WRITE) ? 0 : SEC_READONLY)
@@ -785,7 +782,8 @@ obj_elf_change_section (const char *name,
 }
 
 static bfd_vma
-obj_elf_parse_section_letters (char *str, size_t len, bfd_boolean *is_clone)
+obj_elf_parse_section_letters (char *str, size_t len,
+			       bfd_boolean *is_clone, bfd_vma *gnu_attr)
 {
   bfd_vma attr = 0;
   *is_clone = FALSE;
@@ -819,7 +817,7 @@ obj_elf_parse_section_letters (char *str, size_t len, bfd_boolean *is_clone)
 	  attr |= SHF_TLS;
 	  break;
 	case 'd':
-	  attr |= SHF_GNU_MBIND;
+	  *gnu_attr |= SHF_GNU_MBIND;
 	  break;
 	case '?':
 	  *is_clone = TRUE;
@@ -1011,6 +1009,7 @@ obj_elf_section (int push)
   char *beg;
   int type, dummy;
   bfd_vma attr;
+  bfd_vma gnu_attr;
   int entsize;
   int linkonce;
   subsegT new_subsection = -1;
@@ -1041,6 +1040,7 @@ obj_elf_section (int push)
     return;
   type = SHT_NULL;
   attr = 0;
+  gnu_attr = 0;
   group_name = NULL;
   entsize = 0;
   linkonce = 0;
@@ -1077,7 +1077,8 @@ obj_elf_section (int push)
 	      ignore_rest_of_line ();
 	      return;
 	    }
-	  attr |= obj_elf_parse_section_letters (beg, strlen (beg), &is_clone);
+	  attr |= obj_elf_parse_section_letters (beg, strlen (beg),
+						 &is_clone, &gnu_attr);
 
 	  SKIP_WHITESPACE ();
 	  if (*input_line_pointer == ',')
@@ -1103,14 +1104,14 @@ obj_elf_section (int push)
 		  ++input_line_pointer;
 
 		  if (ISDIGIT (* input_line_pointer))
-		    {
-		      type = strtoul (input_line_pointer, & input_line_pointer, 0);
-		    }
+		    type = strtoul (input_line_pointer, &input_line_pointer, 0);
 		  else
 		    {
 		      c = get_symbol_name (& beg);
 		      (void) restore_line_pointer (c);
-		      type = obj_elf_section_type (beg, input_line_pointer - beg, TRUE);
+		      type = obj_elf_section_type (beg,
+						   input_line_pointer - beg,
+						   TRUE);
 		    }
 		}
 	      else
@@ -1177,7 +1178,7 @@ obj_elf_section (int push)
 		}
 	    }
 
-	  if ((attr & SHF_GNU_MBIND) != 0 && *input_line_pointer == ',')
+	  if ((gnu_attr & SHF_GNU_MBIND) != 0 && *input_line_pointer == ',')
 	    {
 	      ++input_line_pointer;
 	      SKIP_WHITESPACE ();
@@ -1211,7 +1212,8 @@ obj_elf_section (int push)
 	      c = get_symbol_name (& beg);
 	      (void) restore_line_pointer (c);
 
-	      attr |= obj_elf_section_word (beg, input_line_pointer - beg, & type);
+	      attr |= obj_elf_section_word (beg, input_line_pointer - beg,
+					    &type);
 
 	      SKIP_WHITESPACE ();
 	    }
@@ -1226,6 +1228,23 @@ done:
   obj_elf_change_section (name, type, info, attr, entsize, group_name,
 			  linkonce, push);
 
+  if ((gnu_attr & SHF_GNU_MBIND) != 0)
+    {
+      struct elf_backend_data *bed;
+
+      if ((attr & SHF_ALLOC) == 0)
+	as_bad (_("SHF_ALLOC isn't set for GNU_MBIND section: %s"), name);
+
+      bed = (struct elf_backend_data *) get_elf_backend_data (stdoutput);
+      if (bed->elf_osabi == ELFOSABI_NONE)
+	bed->elf_osabi = ELFOSABI_GNU;
+      else if (bed->elf_osabi != ELFOSABI_GNU
+	       && bed->elf_osabi != ELFOSABI_FREEBSD)
+	as_bad (_("GNU_MBIND section is supported only by GNU "
+		  "and FreeBSD targets"));
+    }
+  elf_section_flags (now_seg) |= gnu_attr;
+
   if (push && new_subsection != -1)
     subseg_set (now_seg, new_subsection);
 }
@@ -2032,15 +2051,15 @@ obj_elf_type (int ignore ATTRIBUTE_UNUSED)
 	   || strcmp (type_name, "10") == 0
 	   || strcmp (type_name, "STT_GNU_IFUNC") == 0)
     {
-      const struct elf_backend_data *bed;
-
-      bed = get_elf_backend_data (stdoutput);
-      if (!(bed->elf_osabi == ELFOSABI_GNU
-	    || bed->elf_osabi == ELFOSABI_FREEBSD
-	    /* GNU is still using the default value 0.  */
-	    || bed->elf_osabi == ELFOSABI_NONE))
-	as_bad (_("symbol type \"%s\" is supported only by GNU and FreeBSD targets"),
-		type_name);
+      struct elf_backend_data *bed;
+
+      bed = (struct elf_backend_data *) get_elf_backend_data (stdoutput);
+      if (bed->elf_osabi == ELFOSABI_NONE)
+	bed->elf_osabi = ELFOSABI_GNU;
+      else if (bed->elf_osabi != ELFOSABI_GNU
+	       && bed->elf_osabi != ELFOSABI_FREEBSD)
+	as_bad (_("symbol type \"%s\" is supported only by GNU "
+		  "and FreeBSD targets"), type_name);
       type = BSF_FUNCTION | BSF_GNU_INDIRECT_FUNCTION;
     }
   else if (strcmp (type_name, "gnu_unique_object") == 0)
@@ -2048,14 +2067,12 @@ obj_elf_type (int ignore ATTRIBUTE_UNUSED)
       struct elf_backend_data *bed;
 
       bed = (struct elf_backend_data *) get_elf_backend_data (stdoutput);
-      if (!(bed->elf_osabi == ELFOSABI_GNU
-	    /* GNU is still using the default value 0.  */
-	    || bed->elf_osabi == ELFOSABI_NONE))
+      if (bed->elf_osabi == ELFOSABI_NONE)
+	bed->elf_osabi = ELFOSABI_GNU;
+      else if (bed->elf_osabi != ELFOSABI_GNU)
 	as_bad (_("symbol type \"%s\" is supported only by GNU targets"),
 		type_name);
       type = BSF_OBJECT | BSF_GNU_UNIQUE;
-      /* PR 10549: Always set OSABI field to GNU for objects containing unique symbols.  */
-      bed->elf_osabi = ELFOSABI_GNU;
     }
 #ifdef md_elf_symbol_type
   else if ((type = md_elf_symbol_type (type_name, sym, elfsym)) != -1)
diff --git a/gas/testsuite/gas/elf/section12a.d b/gas/testsuite/gas/elf/section12a.d
index 3e04171..2b6aa3e 100644
--- a/gas/testsuite/gas/elf/section12a.d
+++ b/gas/testsuite/gas/elf/section12a.d
@@ -2,6 +2,8 @@
 #as: --no-pad-sections
 #readelf: -Sg --wide
 #name: mbind sections
+# msp430 and hpux do not support SHF_GNU_MBIND
+#xfail: msp430-*-* *-*-hpux*
 
 #...
   \[[ 0-9]+\] \.mbind\.data[ 	]+PROGBITS[ 	]+0+0 0+[0-9a-f]+ 0+1 00 WAD  0   0  1
diff --git a/gas/testsuite/gas/elf/section12b.d b/gas/testsuite/gas/elf/section12b.d
index 717bc1a..fcbb697 100644
--- a/gas/testsuite/gas/elf/section12b.d
+++ b/gas/testsuite/gas/elf/section12b.d
@@ -2,8 +2,9 @@
 #as: --no-pad-sections
 #objdump: -s
 #name: mbind section contents
-# The RX port annoyingly reorders the sections so that they do not match the sequence expected below.
-#skip: rx-*-*
+# RX annoyingly reorders the sections so that they do not match the sequence
+# expected below.  msp430 and hpux do not support SHF_GNU_MBIND
+#xfail: rx-*-* msp430-*-* *-*-hpux*
 
 #...
 Contents of section .mbind.data:
diff --git a/gas/testsuite/gas/elf/section13.d b/gas/testsuite/gas/elf/section13.d
index 940ccec..9f4fe36 100644
--- a/gas/testsuite/gas/elf/section13.d
+++ b/gas/testsuite/gas/elf/section13.d
@@ -1,2 +1,3 @@
 #name: mbind sections without SHF_ALLOC
 #error_output: section13.l
+#xfail: msp430-*-* *-*-hpux*
diff --git a/gas/testsuite/gas/elf/section13.l b/gas/testsuite/gas/elf/section13.l
index c56b5ae..3ddf54a 100644
--- a/gas/testsuite/gas/elf/section13.l
+++ b/gas/testsuite/gas/elf/section13.l
@@ -1,2 +1,2 @@
 [^:]*: Assembler messages:
-[^:]*:1: Fatal error: SHF_ALLOC isn't set for GNU_MBIND section: .mbind.data
+[^:]*:1: Error: SHF_ALLOC isn't set for GNU_MBIND section: .mbind.data