From a2299ad9c43627fdfde6bd947600ffe42bf961a5 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Tue, 11 Apr 2000 23:01:50 +0000 Subject: Allow address wrap for bitfields again. --- bfd/reloc.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'bfd/reloc.c') 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; -- cgit v1.2.1