Handle ELF compressed header alignment correctly by setting up the section alignment correctly for the Elf32_Chdr or Elf64_Chdr type and respect the ch_addralign field when decompressing the section data.

	PR binutils/23919
binutils* readelf.c (dump_sections_as_strings): Remove bogus addralign check.
	(dump_sections_as_bytes): Likewise.
	(load_specific_debug_sections): Likewise.
	* testsuite/binutils-all/dw2-3.rS: Adjust alignment.
	* testsuite/binutils-all/dw2-3.rt: Likewise.

bfd	* bfd.c (bfd_update_compression_header): Explicitly set alignment.
	(bfd_check_compression_header): Add uncompressed_alignment_power
	argument. Check ch_addralign is a power of 2.
	* bfd-in2.h: Regenerated.
	* compress.c (bfd_compress_section_contents): Get and set
	orig_uncompressed_alignment_pow if section is decompressed.
	(bfd_is_section_compressed_with_header): Add and get
	uncompressed_align_pow_p argument.
	(bfd_is_section_compressed): Add uncompressed_align_power argument
	to bfd_is_section_compressed_with_header call.
	(bfd_init_section_decompress_status): Get and set
	uncompressed_alignment_power.
	* elf.c (_bfd_elf_make_section_from_shdr): Add
	uncompressed_align_power argument to
	bfd_is_section_compressed_with_header call.

5 files changed, 66 insertions, 19 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 35f0706..fd08c72 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,22 @@
+2018-11-27  Mark Wielaard  <mark@klomp.org>
+
+	PR binutils/23919
+	* bfd.c (bfd_update_compression_header): Explicitly set alignment.
+	(bfd_check_compression_header): Add uncompressed_alignment_power
+	argument. Check ch_addralign is a power of 2.
+	* bfd-in2.h: Regenerated.
+	* compress.c (bfd_compress_section_contents): Get and set
+	orig_uncompressed_alignment_pow if section is decompressed.
+	(bfd_is_section_compressed_with_header): Add and get
+	uncompressed_align_pow_p argument.
+	(bfd_is_section_compressed): Add uncompressed_align_power argument
+	to bfd_is_section_compressed_with_header call.
+	(bfd_init_section_decompress_status): Get and set
+	uncompressed_alignment_power.
+	* elf.c (_bfd_elf_make_section_from_shdr): Add
+	uncompressed_align_power argument to
+	bfd_is_section_compressed_with_header call.
+
 2018-11-21  Jozef Lawrynowicz  <jozef.l@mittosystems.com>
 
 	* elf32-msp430.c (elf32_msp430_merge_mspabi_attributes): Do not
diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h
index ee8cd7e..6d92c51 100644
--- a/bfd/bfd-in2.h
+++ b/bfd/bfd-in2.h
@@ -7419,7 +7419,8 @@ void bfd_update_compression_header
 
 bfd_boolean bfd_check_compression_header
    (bfd *abfd, bfd_byte *contents, asection *sec,
-    bfd_size_type *uncompressed_size);
+    bfd_size_type *uncompressed_size,
+    unsigned int *uncompressed_alignment_power);
 
 int bfd_get_compression_header_size (bfd *abfd, asection *sec);
 
@@ -8006,7 +8007,8 @@ void bfd_cache_section_contents
 bfd_boolean bfd_is_section_compressed_with_header
    (bfd *abfd, asection *section,
     int *compression_header_size_p,
-    bfd_size_type *uncompressed_size_p);
+    bfd_size_type *uncompressed_size_p,
+    unsigned int *uncompressed_alignment_power_p);
 
 bfd_boolean bfd_is_section_compressed
    (bfd *abfd, asection *section);
diff --git a/bfd/bfd.c b/bfd/bfd.c
index 15becd7..2b65829 100644
--- a/bfd/bfd.c
+++ b/bfd/bfd.c
@@ -2332,6 +2332,8 @@ bfd_update_compression_header (bfd *abfd, bfd_byte *contents,
 		  bfd_put_32 (abfd, sec->size, &echdr->ch_size);
 		  bfd_put_32 (abfd, 1 << sec->alignment_power,
 			      &echdr->ch_addralign);
+		  /* bfd_log2 (alignof (Elf32_Chdr)) */
+		  bfd_set_section_alignment (abfd, sec, 2);
 		}
 	      else
 		{
@@ -2342,6 +2344,8 @@ bfd_update_compression_header (bfd *abfd, bfd_byte *contents,
 		  bfd_put_64 (abfd, sec->size, &echdr->ch_size);
 		  bfd_put_64 (abfd, 1 << sec->alignment_power,
 			      &echdr->ch_addralign);
+		  /* bfd_log2 (alignof (Elf64_Chdr)) */
+		  bfd_set_section_alignment (abfd, sec, 3);
 		}
 	    }
 	  else
@@ -2354,6 +2358,8 @@ bfd_update_compression_header (bfd *abfd, bfd_byte *contents,
 		 order.  */
 	      memcpy (contents, "ZLIB", 4);
 	      bfd_putb64 (sec->size, contents + 4);
+	      /* No way to keep the original alignment, just use 1 always. */
+	      bfd_set_section_alignment (abfd, sec, 0);
 	    }
 	}
     }
@@ -2368,12 +2374,14 @@ bfd_update_compression_header (bfd *abfd, bfd_byte *contents,
    SYNOPSIS
 	bfd_boolean bfd_check_compression_header
 	  (bfd *abfd, bfd_byte *contents, asection *sec,
-	  bfd_size_type *uncompressed_size);
+	  bfd_size_type *uncompressed_size,
+	  unsigned int *uncompressed_alignment_power);
 
 DESCRIPTION
 	Check the compression header at CONTENTS of SEC in ABFD and
-	store the uncompressed size in UNCOMPRESSED_SIZE if the
-	compression header is valid.
+	store the uncompressed size in UNCOMPRESSED_SIZE and the
+	uncompressed data alignment in UNCOMPRESSED_ALIGNMENT_POWER
+	if the compression header is valid.
 
 RETURNS
 	Return TRUE if the compression header is valid.
@@ -2382,7 +2390,8 @@ RETURNS
 bfd_boolean
 bfd_check_compression_header (bfd *abfd, bfd_byte *contents,
 			      asection *sec,
-			      bfd_size_type *uncompressed_size)
+			      bfd_size_type *uncompressed_size,
+			      unsigned int *uncompressed_alignment_power)
 {
   if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
       && (elf_section_flags (sec) & SHF_COMPRESSED) != 0)
@@ -2404,9 +2413,10 @@ bfd_check_compression_header (bfd *abfd, bfd_byte *contents,
 	  chdr.ch_addralign = bfd_get_64 (abfd, &echdr->ch_addralign);
 	}
       if (chdr.ch_type == ELFCOMPRESS_ZLIB
-	  && chdr.ch_addralign == 1U << sec->alignment_power)
+	  && chdr.ch_addralign == (1U << bfd_log2 (chdr.ch_addralign)))
 	{
 	  *uncompressed_size = chdr.ch_size;
+	  *uncompressed_alignment_power = bfd_log2 (chdr.ch_addralign);
 	  return TRUE;
 	}
     }
diff --git a/bfd/compress.c b/bfd/compress.c
index 53e566e..97ea624 100644
--- a/bfd/compress.c
+++ b/bfd/compress.c
@@ -84,11 +84,13 @@ bfd_compress_section_contents (bfd *abfd, sec_ptr sec,
   int zlib_size = 0;
   int orig_compression_header_size;
   bfd_size_type orig_uncompressed_size;
+  unsigned int orig_uncompressed_alignment_pow;
   int header_size = bfd_get_compression_header_size (abfd, NULL);
   bfd_boolean compressed
     = bfd_is_section_compressed_with_header (abfd, sec,
 					     &orig_compression_header_size,
-					     &orig_uncompressed_size);
+					     &orig_uncompressed_size,
+					     &orig_uncompressed_alignment_pow);
 
   /* Either ELF compression header or the 12-byte, "ZLIB" + 8-byte size,
      overhead in .zdebug* section.  */
@@ -153,6 +155,9 @@ bfd_compress_section_contents (bfd *abfd, sec_ptr sec,
 	      return 0;
 	    }
 	  free (uncompressed_buffer);
+	  bfd_set_section_alignment (abfd, sec,
+				     orig_uncompressed_alignment_pow);
+
 	  sec->contents = buffer;
 	  sec->compress_status = COMPRESS_SECTION_DONE;
 	  return orig_uncompressed_size;
@@ -364,20 +369,24 @@ SYNOPSIS
 	bfd_boolean bfd_is_section_compressed_with_header
 	  (bfd *abfd, asection *section,
 	  int *compression_header_size_p,
-	  bfd_size_type *uncompressed_size_p);
+	  bfd_size_type *uncompressed_size_p,
+	  unsigned int *uncompressed_alignment_power_p);
 
 DESCRIPTION
 	Return @code{TRUE} if @var{section} is compressed.  Compression
-	header size is returned in @var{compression_header_size_p} and
-	uncompressed size is returned in @var{uncompressed_size_p}.  If
-	compression is unsupported, compression header size is returned
-	with -1 and uncompressed size is returned with 0.
+	header size is returned in @var{compression_header_size_p},
+	uncompressed size is returned in @var{uncompressed_size_p}
+	and the uncompressed data alignement power is returned in
+	@var{uncompressed_align_pow_p}.  If compression is
+	unsupported, compression header size is returned with -1
+	and uncompressed size is returned with 0.
 */
 
 bfd_boolean
 bfd_is_section_compressed_with_header (bfd *abfd, sec_ptr sec,
 				       int *compression_header_size_p,
-				       bfd_size_type *uncompressed_size_p)
+				       bfd_size_type *uncompressed_size_p,
+				       unsigned int *uncompressed_align_pow_p)
 {
   bfd_byte header[MAX_COMPRESSION_HEADER_SIZE];
   int compression_header_size;
@@ -412,7 +421,8 @@ bfd_is_section_compressed_with_header (bfd *abfd, sec_ptr sec,
       if (compression_header_size != 0)
 	{
 	  if (!bfd_check_compression_header (abfd, header, sec,
-					     uncompressed_size_p))
+					     uncompressed_size_p,
+					     uncompressed_align_pow_p))
 	    compression_header_size = -1;
 	}
       /* Check for the pathalogical case of a debug string section that
@@ -449,9 +459,11 @@ bfd_is_section_compressed (bfd *abfd, sec_ptr sec)
 {
   int compression_header_size;
   bfd_size_type uncompressed_size;
+  unsigned int uncompressed_align_power;
   return (bfd_is_section_compressed_with_header (abfd, sec,
 						 &compression_header_size,
-						 &uncompressed_size)
+						 &uncompressed_size,
+						 &uncompressed_align_power)
 	  && compression_header_size >= 0
 	  && uncompressed_size > 0);
 }
@@ -480,6 +492,7 @@ bfd_init_section_decompress_status (bfd *abfd, sec_ptr sec)
   int compression_header_size;
   int header_size;
   bfd_size_type uncompressed_size;
+  unsigned int uncompressed_alignment_power = 0;
 
   compression_header_size = bfd_get_compression_header_size (abfd, sec);
   if (compression_header_size > MAX_COMPRESSION_HEADER_SIZE)
@@ -508,7 +521,8 @@ bfd_init_section_decompress_status (bfd *abfd, sec_ptr sec)
       uncompressed_size = bfd_getb64 (header + 4);
     }
   else if (!bfd_check_compression_header (abfd, header, sec,
-					 &uncompressed_size))
+					  &uncompressed_size,
+					  &uncompressed_alignment_power))
     {
       bfd_set_error (bfd_error_wrong_format);
       return FALSE;
@@ -516,6 +530,7 @@ bfd_init_section_decompress_status (bfd *abfd, sec_ptr sec)
 
   sec->compressed_size = sec->size;
   sec->size = uncompressed_size;
+  bfd_set_section_alignment (abfd, sec, uncompressed_alignment_power);
   sec->compress_status = DECOMPRESS_SECTION_SIZED;
 
   return TRUE;
diff --git a/bfd/elf.c b/bfd/elf.c
index bebda20..604971d 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -1177,11 +1177,12 @@ _bfd_elf_make_section_from_shdr (bfd *abfd,
       enum { nothing, compress, decompress } action = nothing;
       int compression_header_size;
       bfd_size_type uncompressed_size;
+      unsigned int uncompressed_align_power;
       bfd_boolean compressed
 	= bfd_is_section_compressed_with_header (abfd, newsect,
 						 &compression_header_size,
-						 &uncompressed_size);
-
+						 &uncompressed_size,
+						 &uncompressed_align_power);
       if (compressed)
 	{
 	  /* Compressed section.  Check if we should decompress.  */