Support ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX

Mark an ALLOC section, which should be placed in special memory area,
with SHF_GNU_MBIND.  Its sh_info field indicates the special memory
type.  GNU_MBIND section names start with ".mbind" so that they are
placed as orphan sections by linker.  All input GNU_MBIND sections
with the same sh_type, sh_flags and sh_info are placed in one output
GNU_MBIND section.  In executable and shared object, create a
GNU_MBIND segment for each GNU_MBIND section and its segment type is
PT_GNU_MBIND_LO plus the sh_info value.  Each GNU_MBIND segment is
aligned at page boundary.

The assembler syntax:

    .section .mbind.foo,"adx",%progbits
                          ^             0: Special memory type.
                          |
                         'd' for SHF_GNU_MBIND.

    .section .mbind.foo,"adx",%progbits,0x1
                          ^             1: Special memory type.
                          |
                         'd' for SHF_GNU_MBIND.

    .section .mbind.bar,"adG",%progbits,.foo_group,comdat,0x2
                          ^                               2: Special memory type.
                          |
                         'd' for SHF_GNU_MBIND.

bfd/

	* elf.c (get_program_header_size): Add a GNU_MBIND segment for
	each GNU_MBIND section and align GNU_MBIND section to page size.
	(_bfd_elf_map_sections_to_segments): Create a GNU_MBIND
	segment for each GNU_MBIND section.
	(_bfd_elf_init_private_section_data): Copy sh_info from input
	for GNU_MBIND section.

binutils/

	* NEWS: Mention support for ELF SHF_GNU_MBIND and
	PT_GNU_MBIND_XXX.
	* readelf.c (get_segment_type): Handle PT_GNU_MBIND_XXX.
	(get_elf_section_flags): Handle SHF_GNU_MBIND.
	(process_section_headers): Likewise.
	* testsuite/binutils-all/mbind1.s: New file.
	* testsuite/binutils-all/objcopy.exp: Run readelf test on
	mbind1.s.

gas/

	* NEWS: Mention support for ELF SHF_GNU_MBIND.
	* config/obj-elf.c (section_match): New.
	(get_section): Match both sh_info and group name.
	(obj_elf_change_section): Add argument for sh_info.  Pass both
	sh_info and group name to get_section. Issue an error for
	SHF_GNU_MBIND section without SHF_ALLOC.  Set sh_info.
	(obj_elf_parse_section_letters): Set SHF_GNU_MBIND for 'd'.
	(obj_elf_section): Support SHF_GNU_MBIND section info.
	* config/obj-elf.h (obj_elf_change_section): Add argument for
	sh_info.
	* config/tc-arm.c (start_unwind_section): Pass 0 as sh_info to
	obj_elf_change_section.
	* config/tc-ia64.c (obj_elf_vms_common): Likewise.
	* config/tc-microblaze.c (microblaze_s_data): Likewise.
	(microblaze_s_sdata): Likewise.
	(microblaze_s_rdata): Likewise.
	(microblaze_s_bss): Likewise.
	* config/tc-mips.c (s_change_section): Likewise.
	* config/tc-msp430.c (msp430_profiler): Likewise.
	* config/tc-rx.c (parse_rx_section): Likewise.
	* config/tc-tic6x.c (tic6x_start_unwind_section): Likewise.
	* doc/as.texinfo: Document 'd' for SHF_GNU_MBIND.
	* testsuite/gas/elf/elf.exp: Run section12a, section12b and
	section13.
	* testsuite/gas/elf/section10.d: Updated.
	* testsuite/gas/elf/section10.s: Likewise.
	* testsuite/gas/elf/section12.s: New file.
	* testsuite/gas/elf/section12a.d: Likewise.
	* testsuite/gas/elf/section12b.d: Likewise.
	* testsuite/gas/elf/section13.l: Likewise.
	* testsuite/gas/elf/section13.d: Likewise.
	* testsuite/gas/elf/section13.s: Likewise.

include/

	* elf/common.h (PT_GNU_MBIND_NUM): New.
	(PT_GNU_MBIND_LO): Likewise.
	(PT_GNU_MBIND_HI): Likewise.
	(SHF_GNU_MBIND): Likewise.

ld/

	* NEWS: Mention support for ELF SHF_GNU_MBIND and
	PT_GNU_MBIND_XXX.
	* emultempl/elf32.em (gld${EMULATION_NAME}_place_orphan): Place
	input GNU_MBIND sections with the same type, attributes and
	sh_info field into a single output GNU_MBIND section.
	* testsuite/ld-elf/elf.exp: Run mbind2a and mbind2b.
	* testsuite/ld-elf/mbind1.s: New file.
	* testsuite/ld-elf/mbind1a.d: Likewise.
	* testsuite/ld-elf/mbind1b.d: Likewise.
	* testsuite/ld-elf/mbind1c.d: Likewise.
	* testsuite/ld-elf/mbind2a.s: Likewise.
	* testsuite/ld-elf/mbind2b.c: Likewise.

1 files changed, 47 insertions, 7 deletions

diff --git a/gas/config/obj-elf.c b/gas/config/obj-elf.c
index 1d59fc0..3696d5e 100644
--- a/gas/config/obj-elf.c
+++ b/gas/config/obj-elf.c
@@ -520,16 +520,26 @@ struct section_stack
 
 static struct section_stack *section_stack;
 
+/* Match both section group name and the sh_info field.  */
+struct section_match
+{
+  const char *group_name;
+  unsigned int info;
+};
+
 static bfd_boolean
 get_section (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *inf)
 {
-  const char *gname = (const char *) inf;
+  struct section_match *match = (struct section_match *) inf;
+  const char *gname = match->group_name;
   const char *group_name = elf_group_name (sec);
+  unsigned int info = elf_section_data (sec)->this_hdr.sh_info;
 
-  return (group_name == gname
-	  || (group_name != NULL
-	      && gname != NULL
-	      && strcmp (group_name, gname) == 0));
+  return (info == match->info
+	  && (group_name == gname
+	      || (group_name != NULL
+		  && gname != NULL
+		  && strcmp (group_name, gname) == 0)));
 }
 
 /* Handle the .section pseudo-op.  This code supports two different
@@ -553,6 +563,7 @@ get_section (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *inf)
 void
 obj_elf_change_section (const char *name,
 			unsigned int type,
+			unsigned int info,
 			bfd_vma attr,
 			int entsize,
 			const char *group_name,
@@ -564,6 +575,7 @@ obj_elf_change_section (const char *name,
   flagword flags;
   const struct elf_backend_data *bed;
   const struct bfd_elf_special_section *ssect;
+  struct section_match match;
 
 #ifdef md_flush_pending_output
   md_flush_pending_output ();
@@ -584,8 +596,10 @@ obj_elf_change_section (const char *name,
   previous_section = now_seg;
   previous_subsection = now_subseg;
 
+  match.group_name = group_name;
+  match.info = info;
   old_sec = bfd_get_section_by_name_if (stdoutput, name, get_section,
-					(void *) group_name);
+					(void *) &match);
   if (old_sec)
     {
       sec = old_sec;
@@ -695,6 +709,9 @@ 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)
@@ -720,6 +737,7 @@ obj_elf_change_section (const char *name,
 	type = bfd_elf_get_default_section_type (flags);
       elf_section_type (sec) = type;
       elf_section_flags (sec) = attr;
+      elf_section_data (sec)->this_hdr.sh_info = info;
 
       /* Prevent SEC_HAS_CONTENTS from being inadvertently set.  */
       if (type == SHT_NOBITS)
@@ -803,6 +821,9 @@ obj_elf_parse_section_letters (char *str, size_t len, bfd_boolean *is_clone)
 	case 'T':
 	  attr |= SHF_TLS;
 	  break;
+	case 'd':
+	  attr |= SHF_GNU_MBIND;
+	  break;
 	case '?':
 	  *is_clone = TRUE;
 	  break;
@@ -996,6 +1017,7 @@ obj_elf_section (int push)
   int entsize;
   int linkonce;
   subsegT new_subsection = -1;
+  unsigned int info = 0;
 
 #ifndef TC_I370
   if (flag_mri)
@@ -1159,6 +1181,23 @@ obj_elf_section (int push)
 		  linkonce = (now_seg->flags & SEC_LINK_ONCE) != 0;
 		}
 	    }
+
+	  if ((attr & SHF_GNU_MBIND) != 0 && *input_line_pointer == ',')
+	    {
+	      ++input_line_pointer;
+	      SKIP_WHITESPACE ();
+	      if (ISDIGIT (* input_line_pointer))
+		{
+		  char *t = input_line_pointer;
+		  info = strtoul (input_line_pointer,
+				  &input_line_pointer, 0);
+		  if (info == (unsigned int) -1)
+		    {
+		      as_warn (_("unsupported mbind section info: %s"), t);
+		      info = 0;
+		    }
+		}
+	    }
 	}
       else
 	{
@@ -1189,7 +1228,8 @@ obj_elf_section (int push)
 done:
   demand_empty_rest_of_line ();
 
-  obj_elf_change_section (name, type, attr, entsize, group_name, linkonce, push);
+  obj_elf_change_section (name, type, info, attr, entsize, group_name,
+			  linkonce, push);
 
   if (push && new_subsection != -1)
     subseg_set (now_seg, new_subsection);