RE: [PATCH] Don't sign extend the addend for R_MIPS_PC16 and R_MIPS_GNU_REL16_S2 if relocations are RELA

[Andrew Bennett <Andrew dot Bennett at imgtec dot com>]

> From: Richard Sandiford [mailto:rdsandiford@googlemail.com]
> Sent: 13 September 2014 09:49
> To: Andrew Bennett
> Cc: binutils@sourceware.org
> Subject: Re: [PATCH] Don't sign extend the addend for R_MIPS_PC16 and
> R_MIPS_GNU_REL16_S2 if relocations are RELA
> 
> Andrew Bennett <Andrew.Bennett@imgtec.com> writes:
> > bfd/
> > 	* elfxx-mips.c (mips_elf_calculate_relocation): Add RELA support to
> > 	R_MIPS_PC16 and R_MIPS_GNU_REL16_S2, and check the offset is 4 byte
> > 	aligned.
> 
> OK, thanks.

I have just noticed that this issue also affects a few other relocations.  The
updated patch and ChangeLog below reflects this.  

Ok to commit?

Many thanks,


Andrew

bfd/
	* elfxx-mips.c (mips_elf_calculate_relocation): Don't sign extend
	the addend if relocations are RELA.


--- a/bfd/elfxx-mips.c
+++ b/bfd/elfxx-mips.c
@@ -5714,7 +5714,9 @@ mips_elf_calculate_relocation (bfd *abfd, bfd *input_bfd,
       return bfd_reloc_continue;
 
     case R_MIPS_16:
-      value = symbol + _bfd_mips_elf_sign_extend (addend, 16);
+      if (howto->partial_inplace)
+	addend = _bfd_mips_elf_sign_extend (addend, 16);
+      value = symbol + addend;
       overflowed_p = mips_elf_overflow_p (value, 16);
       break;
 
@@ -5786,8 +5788,10 @@ mips_elf_calculate_relocation (bfd *abfd, bfd *input_bfd,
 
 	if (was_local_p)
 	  value = addend | ((p + 4) & (0xfc000000 << shift));
-	else
+	else if (howto->partial_inplace)
 	  value = _bfd_mips_elf_sign_extend (addend, 26 + shift);
+	else
+	  value = addend;
 	value = (value + symbol) >> shift;
 	if (!was_local_p && h->root.root.type != bfd_link_hash_undefweak)
 	  overflowed_p = (value >> 26) != ((p + 4) >> (26 + shift));
@@ -5972,7 +5976,13 @@ mips_elf_calculate_relocation (bfd *abfd, bfd *input_bfd,
 
     case R_MIPS_PC16:
     case R_MIPS_GNU_REL16_S2:
-      value = symbol + _bfd_mips_elf_sign_extend (addend, 18) - p;
+      if (howto->partial_inplace)
+	addend = _bfd_mips_elf_sign_extend (addend, 18);
+
+      if ((symbol + addend) & 3)
+	return bfd_reloc_outofrange;
+
+      value = symbol + addend - p;
       overflowed_p = mips_elf_overflow_p (value, 18);
       value >>= howto->rightshift;
       value &= howto->dst_mask;
@@ -6044,28 +6054,36 @@ mips_elf_calculate_relocation (bfd *abfd, bfd *input_bfd,
       break;
 
     case R_MICROMIPS_PC7_S1:
-      value = symbol + _bfd_mips_elf_sign_extend (addend, 8) - p;
+      if (howto->partial_inplace)
+	addend = _bfd_mips_elf_sign_extend (addend, 8);
+      value = symbol + addend - p;
       overflowed_p = mips_elf_overflow_p (value, 8);
       value >>= howto->rightshift;
       value &= howto->dst_mask;
       break;
 
     case R_MICROMIPS_PC10_S1:
-      value = symbol + _bfd_mips_elf_sign_extend (addend, 11) - p;
+      if (howto->partial_inplace)
+	addend = _bfd_mips_elf_sign_extend (addend, 11);
+      value = symbol + addend - p;
       overflowed_p = mips_elf_overflow_p (value, 11);
       value >>= howto->rightshift;
       value &= howto->dst_mask;
       break;
 
     case R_MICROMIPS_PC16_S1:
-      value = symbol + _bfd_mips_elf_sign_extend (addend, 17) - p;
+      if (howto->partial_inplace)
+	addend = _bfd_mips_elf_sign_extend (addend, 17);
+      value = symbol + addend - p;
       overflowed_p = mips_elf_overflow_p (value, 17);
       value >>= howto->rightshift;
       value &= howto->dst_mask;
       break;
 
     case R_MICROMIPS_PC23_S2:
-      value = symbol + _bfd_mips_elf_sign_extend (addend, 25) - ((p | 3) ^ 3);
+      if (howto->partial_inplace)
+	addend = _bfd_mips_elf_sign_extend (addend, 25);
+      value = symbol + addend - ((p | 3) ^ 3);
       overflowed_p = mips_elf_overflow_p (value, 25);
       value >>= howto->rightshift;
       value &= howto->dst_mask;