From 6a17eba5358549d0d6d195bb22b34cdbc068def2 Mon Sep 17 00:00:00 2001 From: Volodymyr Arbatov Date: Mon, 6 May 2013 09:43:21 -0800 Subject: [PATCH] Use signed data type for R_XTENSA_DIFF* relocation offsets. R_XTENSA_DIFF relocation offsets are in fact signed. Treat them as such. Add testcase that examines ld behaviour on R_XTENSA_DIFF relocation changing sign during relaxation. 2014-05-02 Volodymyr Arbatov David Weatherford Max Filippov bfd/ * elf32-xtensa.c (relax_section): treat R_XTENSA_DIFF* relocations as signed. gas/ * config/tc-xtensa.c (md_apply_fix): mark BFD_RELOC_XTENSA_DIFF* fixups as signed. --- Backported from: 1058c7532d0b012ac329219264ddad59049fb6e6 Changes to Changelog files and tests are dropped. bfd/elf32-xtensa.c | 32 +++++++++++++++++--------------- gas/config/tc-xtensa.c | 3 +++ 2 files changed, 20 insertions(+), 15 deletions(-) --- a/bfd/elf32-xtensa.c +++ b/bfd/elf32-xtensa.c @@ -223,11 +223,11 @@ FALSE, 0, 0, FALSE), /* Relocations for supporting difference of symbols. */ - HOWTO (R_XTENSA_DIFF8, 0, 0, 8, FALSE, 0, complain_overflow_bitfield, + HOWTO (R_XTENSA_DIFF8, 0, 0, 8, FALSE, 0, complain_overflow_signed, bfd_elf_xtensa_reloc, "R_XTENSA_DIFF8", FALSE, 0, 0xff, FALSE), - HOWTO (R_XTENSA_DIFF16, 0, 1, 16, FALSE, 0, complain_overflow_bitfield, + HOWTO (R_XTENSA_DIFF16, 0, 1, 16, FALSE, 0, complain_overflow_signed, bfd_elf_xtensa_reloc, "R_XTENSA_DIFF16", FALSE, 0, 0xffff, FALSE), - HOWTO (R_XTENSA_DIFF32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, + HOWTO (R_XTENSA_DIFF32, 0, 2, 32, FALSE, 0, complain_overflow_signed, bfd_elf_xtensa_reloc, "R_XTENSA_DIFF32", FALSE, 0, 0xffffffff, FALSE), /* General immediate operand relocations. */ @@ -9012,7 +9012,8 @@ || r_type == R_XTENSA_DIFF16 || r_type == R_XTENSA_DIFF32) { - bfd_vma diff_value = 0, new_end_offset, diff_mask = 0; + bfd_signed_vma diff_value = 0; + bfd_vma new_end_offset, diff_mask = 0; if (bfd_get_section_limit (abfd, sec) < old_source_offset) { @@ -9026,15 +9027,15 @@ { case R_XTENSA_DIFF8: diff_value = - bfd_get_8 (abfd, &contents[old_source_offset]); + bfd_get_signed_8 (abfd, &contents[old_source_offset]); break; case R_XTENSA_DIFF16: diff_value = - bfd_get_16 (abfd, &contents[old_source_offset]); + bfd_get_signed_16 (abfd, &contents[old_source_offset]); break; case R_XTENSA_DIFF32: diff_value = - bfd_get_32 (abfd, &contents[old_source_offset]); + bfd_get_signed_32 (abfd, &contents[old_source_offset]); break; } @@ -9046,24 +9047,25 @@ switch (r_type) { case R_XTENSA_DIFF8: - diff_mask = 0xff; - bfd_put_8 (abfd, diff_value, + diff_mask = 0x7f; + bfd_put_signed_8 (abfd, diff_value, &contents[old_source_offset]); break; case R_XTENSA_DIFF16: - diff_mask = 0xffff; - bfd_put_16 (abfd, diff_value, + diff_mask = 0x7fff; + bfd_put_signed_16 (abfd, diff_value, &contents[old_source_offset]); break; case R_XTENSA_DIFF32: - diff_mask = 0xffffffff; - bfd_put_32 (abfd, diff_value, + diff_mask = 0x7fffffff; + bfd_put_signed_32 (abfd, diff_value, &contents[old_source_offset]); break; } - /* Check for overflow. */ - if ((diff_value & ~diff_mask) != 0) + /* Check for overflow. Sign bits must be all zeroes or all ones */ + if ((diff_value & ~diff_mask) != 0 && + (diff_value & ~diff_mask) != (-1 & ~diff_mask)) { (*link_info->callbacks->reloc_dangerous) (link_info, _("overflow after relaxation"), --- a/gas/config/tc-xtensa.c +++ b/gas/config/tc-xtensa.c @@ -5868,12 +5868,15 @@ { case BFD_RELOC_8: fixP->fx_r_type = BFD_RELOC_XTENSA_DIFF8; + fixP->fx_signed = 1; break; case BFD_RELOC_16: fixP->fx_r_type = BFD_RELOC_XTENSA_DIFF16; + fixP->fx_signed = 1; break; case BFD_RELOC_32: fixP->fx_r_type = BFD_RELOC_XTENSA_DIFF32; + fixP->fx_signed = 1; break; default: break;