From aca2758cff1f8fdc5ad7b6076ef985ba9ec5f857 Mon Sep 17 00:00:00 2001 From: David Holsgrove Date: Mon, 4 Feb 2013 12:15:22 +1000 Subject: [PATCH 14/16] [LOCAL]: Fixup debug_loc sections after linker relaxation Adds a new reloctype R_MICROBLAZE_32_NONE, used for passing reloc info from the assembler to the linker when the linker manages to fully resolve a local symbol reference. This is a workaround for design flaws in the assembler to linker interface with regards to linker relaxation. Signed-off-by: Edgar E. Iglesias Signed-off-by: David Holsgrove Upstream-Status: Pending --- bfd/bfd-in2.h | 5 +++++ bfd/elf32-microblaze.c | 45 +++++++++++++++++++++++++++++++++++++-------- bfd/libbfd.h | 1 + bfd/reloc.c | 6 ++++++ include/elf/microblaze.h | 1 + 5 files changed, 50 insertions(+), 8 deletions(-) diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h index 8b7f2ee..de38907 100644 --- a/bfd/bfd-in2.h +++ b/bfd/bfd-in2.h @@ -5449,6 +5449,11 @@ value relative to the read-write small data area anchor */ expressions of the form "Symbol Op Symbol" */ BFD_RELOC_MICROBLAZE_32_SYM_OP_SYM, +/* This is a 32 bit reloc that stores the 32 bit pc relative +value in two words (with an imm instruction). No relocation is +done here - only used for relaxing */ + BFD_RELOC_MICROBLAZE_32_NONE, + /* This is a 64 bit reloc that stores the 32 bit pc relative value in two words (with an imm instruction). No relocation is done here - only used for relaxing */ diff --git a/bfd/elf32-microblaze.c b/bfd/elf32-microblaze.c index f90df47..a3f89b9 100644 --- a/bfd/elf32-microblaze.c +++ b/bfd/elf32-microblaze.c @@ -177,6 +177,20 @@ static reloc_howto_type microblaze_elf_howto_raw[] = FALSE), /* PC relative offset? */ /* This reloc does nothing. Used for relaxation. */ + HOWTO (R_MICROBLAZE_32_NONE, /* Type. */ + 0, /* Rightshift. */ + 2, /* Size (0 = byte, 1 = short, 2 = long). */ + 32, /* Bitsize. */ + TRUE, /* PC_relative. */ + 0, /* Bitpos. */ + complain_overflow_bitfield, /* Complain on overflow. */ + NULL, /* Special Function. */ + "R_MICROBLAZE_32_NONE",/* Name. */ + FALSE, /* Partial Inplace. */ + 0, /* Source Mask. */ + 0, /* Dest Mask. */ + FALSE), /* PC relative offset? */ + HOWTO (R_MICROBLAZE_64_NONE, /* Type. */ 0, /* Rightshift. */ 2, /* Size (0 = byte, 1 = short, 2 = long). */ @@ -532,7 +546,10 @@ microblaze_elf_reloc_type_lookup (bfd * abfd ATTRIBUTE_UNUSED, case BFD_RELOC_NONE: microblaze_reloc = R_MICROBLAZE_NONE; break; - case BFD_RELOC_MICROBLAZE_64_NONE: + case BFD_RELOC_MICROBLAZE_32_NONE: + microblaze_reloc = R_MICROBLAZE_32_NONE; + break; + case BFD_RELOC_MICROBLAZE_64_NONE: microblaze_reloc = R_MICROBLAZE_64_NONE; break; case BFD_RELOC_32: @@ -1913,14 +1930,22 @@ microblaze_elf_relax_section (bfd *abfd, } break; case R_MICROBLAZE_NONE: + case R_MICROBLAZE_32_NONE: { /* This was a PC-relative instruction that was completely resolved. */ int sfix, efix; + unsigned int val; bfd_vma target_address; target_address = irel->r_addend + irel->r_offset; sfix = calc_fixup (irel->r_offset, 0, sec); efix = calc_fixup (target_address, 0, sec); + + /* Validate the in-band val. */ + val = bfd_get_32 (abfd, contents + irel->r_offset); + if (val != irel->r_addend && ELF32_R_TYPE (irel->r_info) == R_MICROBLAZE_32_NONE) { + fprintf(stderr, "%d: CORRUPT relax reloc %x %lx\n", __LINE__, val, irel->r_addend); + } irel->r_addend -= (efix - sfix); /* Should use HOWTO. */ microblaze_bfd_write_imm_value_32 (abfd, contents + irel->r_offset, @@ -1968,12 +1993,16 @@ microblaze_elf_relax_section (bfd *abfd, irelscanend = irelocs + o->reloc_count; for (irelscan = irelocs; irelscan < irelscanend; irelscan++) { - if (ELF32_R_TYPE (irelscan->r_info) == (int) R_MICROBLAZE_NONE) + if (1 && ELF32_R_TYPE (irelscan->r_info) == (int) R_MICROBLAZE_32_NONE) { unsigned int val; isym = isymbuf + ELF32_R_SYM (irelscan->r_info); + /* hax: We only do the following fixup for debug location lists. */ + if (strcmp(".debug_loc", o->name)) + continue; + /* This was a PC-relative instruction that was completely resolved. */ if (ocontents == NULL) { @@ -1998,15 +2027,15 @@ microblaze_elf_relax_section (bfd *abfd, } } - irelscan->r_addend -= calc_fixup (irelscan->r_addend - + isym->st_value, sec); val = bfd_get_32 (abfd, ocontents + irelscan->r_offset); + if (val != irelscan->r_addend) { + fprintf(stderr, "%d: CORRUPT relax reloc! %x %lx\n", __LINE__, val, irelscan->r_addend); + } + + irelscan->r_addend -= calc_fixup (irelscan->r_addend, 0, sec); microblaze_bfd_write_imm_value_32 (abfd, ocontents + irelscan->r_offset, irelscan->r_addend); } - if (ELF32_R_TYPE (irelscan->r_info) == (int) R_MICROBLAZE_64_NONE) { - fprintf(stderr, "Unhandled NONE 64\n"); - } if (ELF32_R_TYPE (irelscan->r_info) == (int) R_MICROBLAZE_32) { isym = isymbuf + ELF32_R_SYM (irelscan->r_info); @@ -2066,7 +2095,7 @@ microblaze_elf_relax_section (bfd *abfd, elf_section_data (o)->this_hdr.contents = ocontents; } } - irelscan->r_addend -= calc_fixup (irel->r_addend + irelscan->r_addend -= calc_fixup (irelscan->r_addend + isym->st_value, 0, sec); diff --git a/bfd/libbfd.h b/bfd/libbfd.h index 09f307f..840c662 100644 --- a/bfd/libbfd.h +++ b/bfd/libbfd.h @@ -2644,6 +2644,7 @@ static const char *const bfd_reloc_code_real_names[] = { "@@uninitialized@@", "BFD_RELOC_MICROBLAZE_32_ROSDA", "BFD_RELOC_MICROBLAZE_32_RWSDA", "BFD_RELOC_MICROBLAZE_32_SYM_OP_SYM", + "BFD_RELOC_MICROBLAZE_32_NONE", "BFD_RELOC_MICROBLAZE_64_NONE", "BFD_RELOC_MICROBLAZE_64_GOTPC", "BFD_RELOC_MICROBLAZE_64_GOT", diff --git a/bfd/reloc.c b/bfd/reloc.c index 7f46c58..5bcd52d 100644 --- a/bfd/reloc.c +++ b/bfd/reloc.c @@ -6396,6 +6396,12 @@ ENUMDOC This is a 32 bit reloc for the microblaze to handle expressions of the form "Symbol Op Symbol" ENUM + BFD_RELOC_MICROBLAZE_32_NONE +ENUMDOC + This is a 32 bit reloc that stores the 32 bit pc relative + value in two words (with an imm instruction). No relocation is + done here - only used for relaxing +ENUM BFD_RELOC_MICROBLAZE_64_NONE ENUMDOC This is a 64 bit reloc that stores the 32 bit pc relative diff --git a/include/elf/microblaze.h b/include/elf/microblaze.h index effca20..f8420dc 100644 --- a/include/elf/microblaze.h +++ b/include/elf/microblaze.h @@ -58,6 +58,7 @@ START_RELOC_NUMBERS (elf_microblaze_reloc_type) RELOC_NUMBER (R_MICROBLAZE_TLSDTPREL64, 27) /* TLS Offset Within TLS Block */ RELOC_NUMBER (R_MICROBLAZE_TLSGOTTPREL32, 28) /* TLS Offset From Thread Pointer */ RELOC_NUMBER (R_MICROBLAZE_TLSTPREL32, 29) /* TLS Offset From Thread Pointer */ + RELOC_NUMBER (R_MICROBLAZE_32_NONE, 30) END_RELOC_NUMBERS (R_MICROBLAZE_max) -- 1.9.0