In the linkers, collect objects in section "openbsd.mutable" and place

them into a page-aligned region in the bss, with the right markers for
kernel/ld.so to identify the region and skip making it immutable.
While here, fix readelf/objdump versions to show all of this.
ok miod kettenis

4 files changed, 34 insertions, 1 deletions

diff --git a/gnu/usr.bin/binutils-2.17/bfd/elf.c b/gnu/usr.bin/binutils-2.17/bfd/elf.c
index f8658be09fe..2d2ed030eca 100644
--- a/gnu/usr.bin/binutils-2.17/bfd/elf.c
+++ b/gnu/usr.bin/binutils-2.17/bfd/elf.c
@@ -1103,6 +1103,7 @@ get_segment_type (unsigned int p_type)
     case PT_OPENBSD_RANDOMIZE: pt = "OPENBSD_RANDOMIZE"; break;
     case PT_OPENBSD_WXNEEDED: pt = "OPENBSD_WXNEEDED"; break;
     case PT_OPENBSD_BOOTDATA: pt = "OPENBSD_BOOTDATA"; break;
+    case PT_OPENBSD_MUTABLE: pt = "OPENBSD_MUTABLE"; break;
     default: pt = NULL; break;
     }
   return pt;
@@ -2645,6 +2646,9 @@ bfd_section_from_phdr (bfd *abfd, Elf_Internal_Phdr *hdr, int index)
       return _bfd_elf_make_section_from_phdr (abfd, hdr, index,
 					      "openbsd_wxneeded");
 
+    case PT_OPENBSD_MUTABLE:
+      return _bfd_elf_make_section_from_phdr (abfd, hdr, index,
+					      "openbsd_mutable");
     default:
       /* Check for any processor-specific program segment types.  */
       bed = get_elf_backend_data (abfd);
@@ -3649,7 +3653,7 @@ map_sections_to_segments (bfd *abfd)
   bfd_boolean writable;
   int tls_count = 0;
   asection *first_tls = NULL;
-  asection *dynsec, *eh_frame_hdr, *randomdata;
+  asection *dynsec, *eh_frame_hdr, *randomdata, *mutabledata;
   bfd_size_type amt;
 
   if (elf_tdata (abfd)->segment_map != NULL)
@@ -4002,6 +4006,24 @@ map_sections_to_segments (bfd *abfd)
       pm = &m->next;
     }
 
+  /* If there is a .openbsd.mutable section, throw in a PT_OPENBSD_MUTABLE
+     segment.  */
+  mutabledata = bfd_get_section_by_name (abfd, ".openbsd.mutable");
+  if (mutabledata != NULL && (mutabledata->flags & SEC_LOAD) != 0)
+    {
+      amt = sizeof (struct elf_segment_map);
+      m = bfd_zalloc (abfd, amt);
+      if (m == NULL)
+	goto error_return;
+      m->next = NULL;
+      m->p_type = PT_OPENBSD_MUTABLE;
+      m->count = 1;
+      m->sections[0] = mutabledata->output_section;
+
+      *pm = m;
+      pm = &m->next;
+    }
+
   if (elf_tdata (abfd)->relro)
     {
       amt = sizeof (struct elf_segment_map);
@@ -4747,6 +4769,12 @@ get_program_header_size (bfd *abfd)
       ++segs;
     }
 
+  if (bfd_get_section_by_name (abfd, ".openbsd.mutable") != NULL)
+    {
+      /* We need a PT_OPENBSD_MUTABLE segment.  */
+      ++segs;
+    }
+
   if (elf_tdata (abfd)->eh_frame_hdr)
     {
       /* We need a PT_GNU_EH_FRAME segment.  */
diff --git a/gnu/usr.bin/binutils-2.17/binutils/readelf.c b/gnu/usr.bin/binutils-2.17/binutils/readelf.c
index 716b2768e2e..d0f16f3b6dd 100644
--- a/gnu/usr.bin/binutils-2.17/binutils/readelf.c
+++ b/gnu/usr.bin/binutils-2.17/binutils/readelf.c
@@ -2708,6 +2708,8 @@ get_segment_type (unsigned long p_type)
 			return "OPENBSD_WXNEEDED";
     case PT_OPENBSD_BOOTDATA:
 			return "OPENBSD_BOOTDATA";
+    case PT_OPENBSD_MUTABLE:
+			return "OPENBSD_MUTABLE";
 
     default:
       if ((p_type >= PT_LOPROC) && (p_type <= PT_HIPROC))
diff --git a/gnu/usr.bin/binutils-2.17/include/elf/common.h b/gnu/usr.bin/binutils-2.17/include/elf/common.h
index 1e535ef0b2d..8ceb3d21d45 100644
--- a/gnu/usr.bin/binutils-2.17/include/elf/common.h
+++ b/gnu/usr.bin/binutils-2.17/include/elf/common.h
@@ -313,6 +313,7 @@
 #define PT_OPENBSD_RANDOMIZE	0x65a3dbe6 /* Fill with random data. */
 #define PT_OPENBSD_WXNEEDED	0x65a3dbe7 /* Program does W^X violations */
 #define PT_OPENBSD_BOOTDATA	0x65a41be6 /* Section for boot arguments */
+#define PT_OPENBSD_MUTABLE	0x65a3dbe5 /* Section for boot arguments */
 
 /* Program segment permissions, in program header p_flags field.  */
 
diff --git a/gnu/usr.bin/binutils-2.17/ld/ldgram.y b/gnu/usr.bin/binutils-2.17/ld/ldgram.y
index 33ccd4d60f5..86924249835 100644
--- a/gnu/usr.bin/binutils-2.17/ld/ldgram.y
+++ b/gnu/usr.bin/binutils-2.17/ld/ldgram.y
@@ -1097,6 +1097,8 @@ phdr_type:
 			    $$ = exp_intop (0x65a3dbe7);
 			  else if (strcmp (s, "PT_OPENBSD_BOOTDATA") == 0)
 			    $$ = exp_intop (0x65a41be6);
+			  else if (strcmp (s, "PT_OPENBSD_MUTABLE") == 0)
+			    $$ = exp_intop (0x65a3dbe5);
 			  else
 			    {
 			      einfo (_("\