For the Thumb BLX reloc round the relocation up rather than down.

3 files changed, 30 insertions, 25 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 25af58b0793..0f2d311a65f 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2002-05-23  Nick Clifton  <nickc@cambridge.redhat.com>
+
+	* elf32-arm.h (elf32_arm_final_link_relocate): For the Thumb
+	BLX reloc round the relocation up rather than down.
+	* coff-arm.c (coff_arm_relocate_section): Likewise.
+
 2002-05-21  H.J. Lu  (hjl@gnu.org)
 
 	* linker.c (_bfd_generic_link_add_one_symbol): Allow multiple
diff --git a/bfd/coff-arm.c b/bfd/coff-arm.c
index 1619e670c3d..5e7f907a959 100644
--- a/bfd/coff-arm.c
+++ b/bfd/coff-arm.c
@@ -1701,21 +1701,23 @@ coff_arm_relocate_section (output_bfd, info, input_bfd, input_section,
 		  || signed_check < reloc_signed_min)
 		overflow = true;
 
-	      /* For the BLX(1) instruction remove bit 0 of the adjusted offset.
-		 Bit 0 can only be set if the upper insn is at a half-word boundary,
-		 since the destination address, an ARM instruction, must always be
-		 on a word boundary.  The semantics of the BLX (1) instruction,
-		 however, are that bit 0 in the offset must always be 0, and the
-		 corresponding bit 1 in the target address will be set from bit
-		 1 of the source address.  */
-	      if ((x & 0x18000000) == 0x08000000)
-		relocation &= ~0x2;
-
-	      /* Put the relocation into the correct bits.  */
+	      /* Put the relocation into the correct bits.
+		 For a BLX instruction, make sure that the relocation is rounded up
+		 to a word boundary.  This follows the semantics of the instruction
+		 which specifies that bit 1 of the target address will come from bit
+		 1 of the base address.  */
 	      if (bfd_big_endian (input_bfd))
-		relocation = (((relocation & 0xffe) >> 1)  | ((relocation << 4) & 0x07ff0000));
+	        {
+		  if ((x & 0x1800) == 0x0800 && (relocation & 0x02))
+		    relocation += 2;
+		  relocation = (((relocation & 0xffe) >> 1)  | ((relocation << 4) & 0x07ff0000));
+		}
 	      else
-		relocation = (((relocation & 0xffe) << 15) | ((relocation >> 12) & 0x7ff));
+	        {
+		  if ((x & 0x18000000) == 0x08000000 && (relocation & 0x02))
+		    relocation += 2;
+		  relocation = (((relocation & 0xffe) << 15) | ((relocation >> 12) & 0x7ff));
+		}
 
 	      /* Add the relocation to the correct bits of X.  */
 	      x = ((x & ~howto->dst_mask) | relocation);
diff --git a/bfd/elf32-arm.h b/bfd/elf32-arm.h
index 91ea63b38b0..8b9bf073f16 100644
--- a/bfd/elf32-arm.h
+++ b/bfd/elf32-arm.h
@@ -1471,22 +1471,19 @@ elf32_arm_final_link_relocate (howto, input_bfd, output_bfd,
 	if (signed_check > reloc_signed_max || signed_check < reloc_signed_min)
 	  overflow = true;
 
-	/* Put RELOCATION back into the insn.  */
-	upper_insn = (upper_insn & ~(bfd_vma) 0x7ff) | ((relocation >> 12) & 0x7ff);
-	lower_insn = (lower_insn & ~(bfd_vma) 0x7ff) | ((relocation >> 1) & 0x7ff);
-
 #ifndef OLD_ARM_ABI
 	if (r_type == R_ARM_THM_XPC22
 	    && ((lower_insn & 0x1800) == 0x0800))
-	  /* Remove bit zero of the adjusted offset.  Bit zero can only be
-	     set if the upper insn is at a half-word boundary, since the
-	     destination address, an ARM instruction, must always be on a
-	     word boundary.  The semantics of the BLX (1) instruction, however,
-	     are that bit zero in the offset must always be zero, and the
-	     corresponding bit one in the target address will be set from bit
-	     one of the source address.  */
-	  lower_insn &= ~1;
+	  /* For a BLX instruction, make sure that the relocation is rounded up
+	     to a word boundary.  This follows the semantics of the instruction
+	     which specifies that bit 1 of the target address will come from bit
+	     1 of the base address.  */
+	  relocation = (relocation + 2) & ~ 3;
 #endif
+	/* Put RELOCATION back into the insn.  */
+	upper_insn = (upper_insn & ~(bfd_vma) 0x7ff) | ((relocation >> 12) & 0x7ff);
+	lower_insn = (lower_insn & ~(bfd_vma) 0x7ff) | ((relocation >> 1) & 0x7ff);
+
 	/* Put the relocated value back in the object file:  */
 	bfd_put_16 (input_bfd, upper_insn, hit_data);
 	bfd_put_16 (input_bfd, lower_insn, hit_data + 2);