From fbab8933bca6b7dba2aa19190a71f799a370c3d4 Mon Sep 17 00:00:00 2001 From: Stafford Horne Date: Sun, 2 Jan 2022 09:03:28 +0900 Subject: [PATCH] or1k: Avoid R_OR1K_GOT16 signed overflow by using special howto Previously when fixing PR 21464 we masked out upper bits of the relocation value in order to avoid overflow complaints when acceptable. It turns out this does not work when the relocation value ends up being signed. To fix this this patch introduces a special howto with complain_on_overflow set to complain_overflow_dont. This is used in place of the normal R_OR1K_GOT16 howto when we detect R_OR1K_GOT_AHI16 relocations. bfd/ChangeLog: PR 28735 * elf32-or1k.c (or1k_elf_got16_no_overflow_howto): Define. (or1k_elf_relocate_section): Use new howto instead of trying to mask out relocation bits. Signed-off-by: Giulio Benetti --- bfd/elf32-or1k.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/bfd/elf32-or1k.c b/bfd/elf32-or1k.c index 2ff998066a8..3df31172fcb 100644 --- a/bfd/elf32-or1k.c +++ b/bfd/elf32-or1k.c @@ -828,6 +828,23 @@ static reloc_howto_type or1k_elf_howto_table[] = FALSE), /* pcrel_offset */ }; +/* A copy of the R_OR1K_GOT16 used in the presense of R_OR1K_GOT_AHI16 + relocations when we know we can ignore overflows. */ +static reloc_howto_type or1k_elf_got16_no_overflow_howto = + HOWTO (R_OR1K_GOT16, /* type */ + 0, /* rightshift */ + 2, /* size (0 = byte, 1 = short, 2 = long) */ + 16, /* bitsize */ + FALSE, /* pc_relative */ + 0, /* bitpos */ + complain_overflow_dont, /* complain_on_overflow */ + bfd_elf_generic_reloc, /* special_function */ + "R_OR1K_GOT16", /* name */ + FALSE, /* partial_inplace */ + 0, /* src_mask */ + 0xffff, /* dst_mask */ + FALSE); /* pcrel_offset */ + /* Map BFD reloc types to Or1k ELF reloc types. */ struct or1k_reloc_map @@ -1508,12 +1525,11 @@ or1k_elf_relocate_section (bfd *output_bfd, if (r_type == R_OR1K_GOT_AHI16) saw_gotha = TRUE; - /* If we have a R_OR1K_GOT16 followed by a R_OR1K_GOT_AHI16 + /* If we have a R_OR1K_GOT16 following a R_OR1K_GOT_AHI16 relocation we assume the code is doing the right thing to avoid - overflows. Here we mask the lower 16-bit of the relocation to - avoid overflow validation failures. */ + overflows. */ if (r_type == R_OR1K_GOT16 && saw_gotha) - relocation &= 0xffff; + howto = &or1k_elf_got16_no_overflow_howto; /* Addend should be zero. */ if (rel->r_addend != 0) -- 2.25.1