From 8a4ac87108a0ad21e0fa7890ee7bbdba5eb92ad5 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Tue, 11 Apr 2000 23:01:50 +0000 Subject: [PATCH] Allow address wrap for bitfields again. --- bfd/ChangeLog | 6 ++++++ bfd/reloc.c | 20 +++++++++++--------- 2 files changed, 17 insertions(+), 9 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 3321d25d57b..0fe0d2949e1 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,9 @@ +2000-04-12 Alan Modra + + * reloc.c (_bfd_relocate_contents): In complain_overflow_bitfield + case, allow address wrap-around stupidly removed 2000-03-17. Sign + extend without an if statement. + 2000-04-11 Alan Modra * coff-mips.c (mips_gprel_reloc): Test for 16 bit range using diff --git a/bfd/reloc.c b/bfd/reloc.c index 8823c6ce53e..f312ffc5b72 100644 --- a/bfd/reloc.c +++ b/bfd/reloc.c @@ -1498,11 +1498,9 @@ _bfd_relocate_contents (howto, input_bfd, relocation, location) trouble; we would need to verify that B is in range, as we do for A above. */ signmask = ((~ howto->src_mask) >> 1) & howto->src_mask; - if ((b & signmask) != 0) - { - /* Set all the bits above the sign bit. */ - b -= signmask << 1; - } + + /* Set all the bits above the sign bit. */ + b = (b ^ signmask) - signmask; b = (b & addrmask) >> bitpos; @@ -1545,7 +1543,7 @@ _bfd_relocate_contents (howto, input_bfd, relocation, location) case complain_overflow_bitfield: /* Much like the signed check, but for a field one bit - wider, and no trimming with addrmask. We allow a + wider, and no trimming inputs with addrmask. We allow a bitfield to represent numbers in the range -2**n to 2**n-1, where n is the number of bits in the field. Note that when bfd_vma is 32 bits, a 32-bit reloc can't @@ -1558,15 +1556,19 @@ _bfd_relocate_contents (howto, input_bfd, relocation, location) flag = bfd_reloc_overflow; signmask = ((~ howto->src_mask) >> 1) & howto->src_mask; - if ((b & signmask) != 0) - b -= signmask << 1; + b = (b ^ signmask) - signmask; b >>= bitpos; sum = a + b; + /* We mask with addrmask here to explicitly allow an address + wrap-around. The Linux kernel relies on it, and it is + the only way to write assembler code which can run when + loaded at a location 0x80000000 away from the location at + which it is linked. */ signmask = fieldmask + 1; - if (((~ (a ^ b)) & (a ^ sum)) & signmask) + if (((~ (a ^ b)) & (a ^ sum)) & signmask & addrmask) flag = bfd_reloc_overflow; break; -- 2.30.2