Add ability to change linker warning messages into errors when reporting executable stacks and/or executable segments.

  include
  * bfdlink.h (struct bfd_link_info): Update descriptions of the 'execstack', 'noexecstack' and 'warn_execstack' fields. Add 'error_exectack' and 'warn_is_error_for_rwx_segments' fields.

  bfd
  * elf.c (assign_file_positions_except_relocs): Turn warnings about executable segments into errors if so requested.
  * elflink.c (bfd_elf_size_dynamic_sections): Turn warnings about executable stacks into errors if so requested.

  ld
  * ldlex.h (enum option_values): Add OPTION_ERROR_EXECSTACK, OPTION_NO_ERROR_EXECSTACK, OPTION_WARN_EXECSTACK_OBJECTS, OPTION_ERROR_RWX_SEGMENTS and OPTION_NO_ERROR_RWX_SEGMENTS. (struct ld_option): Add new long options. (parse_args): Parse new long options. (elf_static_list_options): Display the new options.
  * ld.texi: Document the new command line options.
  * configure.ac (error-execstack): New configuration option. (error-rwx-segments): New configuration option.
  * emultempl/elf.em (_before_parse): Initialse the new linkinfo fields.
  * NEWS: Mention the new features.
  * config.in: Regenerate.
  * configure: Regenerate.
  * testsuite/ld-elf/commonpage2.d: Disable errors for RWX segments and/or executable stacks.
  * testsuite/ld-elf/elf.exp: Likewise.
  * testsuite/ld-elf/header.d: Likewise.
  * testsuite/ld-elf/loadaddr1.d: Likewise.
  * testsuite/ld-elf/loadaddr2.d: Likewise.
  * testsuite/ld-elf/maxpage4.d: Likewise.
  * testsuite/ld-elf/nobits-1.d: Likewise.
  * testsuite/ld-elf/note-1.d: Likewise.
  * testsuite/ld-elf/orphan-10.d: Likewise.
  * testsuite/ld-elf/orphan-11.d: Likewise.
  * testsuite/ld-elf/orphan-12.d: Likewise.
  * testsuite/ld-elf/orphan-5.d: Likewise.
  * testsuite/ld-elf/orphan-7.d: Likewise.
  * testsuite/ld-elf/orphan-8.d: Likewise.
  * testsuite/ld-elf/orphan-9.d: Likewise.
  * testsuite/ld-elf/orphan-region.d: Likewise.
  * testsuite/ld-elf/orphan.d: Likewise.
  * testsuite/ld-elf/pr19539.d: Likewise.
  * testsuite/ld-elf/pr26256-1a.d: Likewise.
  * testsuite/ld-elf/pr26907.d: Likewise.
  * testsuite/ld-elf/pr28597.d: Likewise.
  * testsuite/ld-elf/retain2.d: Likewise.
  * testsuite/ld-elf/shared.exp: Likewise.
  * testsuite/ld-elf/size-1.d: Likewise.
  * testsuite/ld-elf/textaddr7.d: Likewise.
  * testsuite/ld-elf/warn1.d: Likewise.
  * testsuite/ld-elf/warn2.d: Likewise.
  * testsuite/ld-i386/discarded1.d: Likewise.
  * testsuite/ld-i386/pr19175.d: Likewise.
  * testsuite/ld-i386/pr19539.d: Likewise.
  * testsuite/ld-i386/pr23189.d: Likewise.
  * testsuite/ld-plugin/lto-3r.d: Likewise.
  * testsuite/ld-plugin/lto-5r.d: Likewise.
  * testsuite/ld-plugin/lto.exp: Likewise.
  * testsuite/ld-powerpc/ppc476-shared.d: Likewise.
  * testsuite/ld-powerpc/ppc476-shared2.d: Likewise.
  * testsuite/ld-powerpc/pr28827-2.d: Likewise.
  * testsuite/ld-s390/s390.exp: Likewise.
  * testsuite/ld-scripts/align2a.d: Likewise.
  * testsuite/ld-scripts/align2b.d: Likewise.
  * testsuite/ld-scripts/align5.d: Likewise.
  * testsuite/ld-scripts/alignof.exp: Likewise.
  * testsuite/ld-scripts/crossref.exp: Likewise.
  * testsuite/ld-scripts/defined2.d: Likewise.
  * testsuite/ld-scripts/defined3.d: Likewise.
  * testsuite/ld-scripts/defined5.d: Likewise.
  * testsuite/ld-scripts/pr14962.d: Likewise.
  * testsuite/ld-scripts/pr18963.d: Likewise.
  * testsuite/ld-scripts/pr20302.d: Likewise.
  * testsuite/ld-scripts/print-memory-usage.exp: Likewise.
  * testsuite/ld-scripts/rgn-at1.d: Likewise.
  * testsuite/ld-scripts/rgn-at10.d: Likewise.
  * testsuite/ld-scripts/rgn-at4.d: Likewise.
  * testsuite/ld-scripts/rgn-at6.d: Likewise.
  * testsuite/ld-scripts/rgn-at8.d: Likewise.
  * testsuite/ld-scripts/rgn-at9.d: Likewise.
  * testsuite/ld-scripts/rgn-over1.d: Likewise.
  * testsuite/ld-scripts/rgn-over2.d: Likewise.
  * testsuite/ld-scripts/rgn-over4.d: Likewise.
  * testsuite/ld-scripts/rgn-over5.d: Likewise.
  * testsuite/ld-scripts/rgn-over6.d: Likewise.
  * testsuite/ld-scripts/script.exp: Likewise.
  * testsuite/ld-scripts/sizeof.exp: Likewise.
  * testsuite/ld-scripts/sort-file.d: Likewise.
  * testsuite/ld-x86-64/discarded1.d: Likewise.
  * testsuite/ld-x86-64/pr19175.d: Likewise.
  * testsuite/ld-x86-64/pr19539a.d: Likewise.
  * testsuite/ld-x86-64/pr19539b.d: Likewise.
  * testsuite/ld-x86-64/pr23189.d: Likewise.

2 files changed, 37 insertions, 8 deletions

diff --git a/include/ChangeLog b/include/ChangeLog
index e0f0cb3..7ea77f8 100644
--- a/include/ChangeLog
+++ b/include/ChangeLog
@@ -1,3 +1,9 @@
+2023-11-10  Nick Clifton  <nickc@redhat.com>
+
+	* bfdlink.h (struct bfd_link_info): Update descriptions of the
+	'execstack', 'noexecstack' and 'warn_execstack'	fields.
+	Add 'error_exectack' and 'warn_is_error_for_rwx_segments' fields.
+
 2023-10-30  Nick Clifton  <nickc@redhat.com>
 
 	* elf/bpf.h (R_BPF_64_NODYLD32): Add a note that this reloc is
diff --git a/include/bfdlink.h b/include/bfdlink.h
index 840790a..8882257 100644
--- a/include/bfdlink.h
+++ b/include/bfdlink.h
@@ -484,26 +484,49 @@ struct bfd_link_info
      --dynamic-list command line options.  */
   unsigned int dynamic: 1;
 
-  /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
-     flags.  */
+  /* Set if the "-z execstack" option has been used to request that a
+     PT_GNU_STACK segment should be created with PF_R, PF_W and PF_X
+     flags set.
+
+     Note - if performing a relocatable link then a .note.GNU-stack
+     section will be created instead, if one does not exist already.
+     The section will have the SHF_EXECINSTR flag bit set.  */
   unsigned int execstack: 1;
 
-  /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
-     flags.  */
+  /* Set if the "-z noexecstack" option has been used to request that a
+     PT_GNU_STACK segment should be created with PF_R and PF_W flags.  Or
+     a non-executable .note.GNU-stack section for relocateable links.
+
+     Note - this flag is not quite orthogonal to execstack, since both
+     of these flags can be 0.  In this case a stack segment can still
+     be created, but it will only have the PF_X flag bit set if one or
+     more of the input files contains a .note.GNU-stack section with the
+     SHF_EXECINSTR flag bit set, or if the default behaviour for the
+     architecture is to create executable stacks.
+
+     The execstack and noexecstack flags should never both be 1.  */
   unsigned int noexecstack: 1;
 
   /* Tri-state variable:
      0 => do not warn when creating an executable stack.
-     1 => always warn when creating an executable stack.
-     >1 => warn when creating an executable stack if execstack is 0.  */
+     1 => always warn when creating an executable stack (for any reason).
+     2 => only warn when an executable stack has been requested an object
+          file and execstack is 0 or noexecstack is 1.
+     3 => not used.  */
   unsigned int warn_execstack: 2;
+  /* TRUE if a warning generated because of warn_execstack should be instead
+     be treated as an error.  */
+  unsigned int error_execstack: 1;
 
-  /* TRUE if warnings should not be generated for TLS segments with eXecute
+  /* TRUE if warnings should NOT be generated for TLS segments with eXecute
      permission or LOAD segments with RWX permissions.  */
   unsigned int no_warn_rwx_segments: 1;
   /* TRUE if the user gave either --warn-rwx-segments or
-     --no-warn-rwx-segments.  */
+     --no-warn-rwx-segments on the linker command line.  */
   unsigned int user_warn_rwx_segments: 1;
+  /* TRUE if warnings generated when no_warn_rwx_segements is 0 should
+     instead be treated as errors.  */
+  unsigned int warn_is_error_for_rwx_segments: 1;
 
   /* TRUE if the stack can be made executable because of the absence of a
      .note.GNU-stack section in an input file.  Note - even if this field