/* BFD support for handling relocation entries.
Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
- 2000, 2001, 2002, 2003, 2004, 2005
+ 2000, 2001, 2002, 2003, 2004, 2005, 2006
Free Software Foundation, Inc.
Written by Cygnus Support.
. {* Do not complain on overflow. *}
. complain_overflow_dont,
.
-. {* Complain if the bitfield overflows, whether it is considered
-. as signed or unsigned. *}
+. {* Complain if the value overflows when considered as a signed
+. number one bit larger than the field. ie. A bitfield of N bits
+. is allowed to represent -2**n to 2**n-1. *}
. complain_overflow_bitfield,
.
-. {* Complain if the value overflows when considered as signed
+. {* Complain if the value overflows when considered as a signed
. number. *}
. complain_overflow_signed,
.
bfd_vma fieldmask, addrmask, signmask, ss, a;
bfd_reloc_status_type flag = bfd_reloc_ok;
- a = relocation;
-
/* Note: BITSIZE should always be <= ADDRSIZE, but in case it's not,
we'll be permissive: extra bits in the field mask will
automatically extend the address mask for purposes of the
overflow check. */
fieldmask = N_ONES (bitsize);
+ signmask = ~fieldmask;
addrmask = N_ONES (addrsize) | fieldmask;
+ a = (relocation & addrmask) >> rightshift;;
switch (how)
{
case complain_overflow_signed:
/* If any sign bits are set, all sign bits must be set. That
is, A must be a valid negative address after shifting. */
- a = (a & addrmask) >> rightshift;
signmask = ~ (fieldmask >> 1);
- ss = a & signmask;
- if (ss != 0 && ss != ((addrmask >> rightshift) & signmask))
- flag = bfd_reloc_overflow;
- break;
-
- case complain_overflow_unsigned:
- /* We have an overflow if the address does not fit in the field. */
- a = (a & addrmask) >> rightshift;
- if ((a & ~ fieldmask) != 0)
- flag = bfd_reloc_overflow;
- break;
+ /* Fall thru */
case complain_overflow_bitfield:
/* Bitfields are sometimes signed, sometimes unsigned. We
of n bits is allowed to store -2**n to 2**n-1. Thus overflow
if the value has some, but not all, bits set outside the
field. */
- a >>= rightshift;
- ss = a & ~ fieldmask;
- if (ss != 0 && ss != (((bfd_vma) -1 >> rightshift) & ~ fieldmask))
+ ss = a & signmask;
+ if (ss != 0 && ss != ((addrmask >> rightshift) & signmask))
+ flag = bfd_reloc_overflow;
+ break;
+
+ case complain_overflow_unsigned:
+ /* We have an overflow if the address does not fit in the field. */
+ if ((a & signmask) != 0)
flag = bfd_reloc_overflow;
break;
the size of an address. For bitfields, all the bits matter.
See also bfd_check_overflow. */
fieldmask = N_ONES (howto->bitsize);
+ signmask = ~fieldmask;
addrmask = N_ONES (bfd_arch_bits_per_address (input_bfd)) | fieldmask;
- a = relocation;
- b = x & howto->src_mask;
+ a = (relocation & addrmask) >> rightshift;
+ b = (x & howto->src_mask & addrmask) >> bitpos;
switch (howto->complain_on_overflow)
{
case complain_overflow_signed:
- a = (a & addrmask) >> rightshift;
-
/* If any sign bits are set, all sign bits must be set.
That is, A must be a valid negative address after
shifting. */
- signmask = ~ (fieldmask >> 1);
+ signmask = ~(fieldmask >> 1);
+ /* Fall thru */
+
+ case complain_overflow_bitfield:
+ /* Much like the signed check, but for a field one bit
+ wider. 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 overflow, which is exactly what we want. */
ss = a & signmask;
if (ss != 0 && ss != ((addrmask >> rightshift) & signmask))
flag = bfd_reloc_overflow;
SRC_MASK has more bits than BITSIZE, we can get into
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;
+ ss = ((~howto->src_mask) >> 1) & howto->src_mask;
+ ss >>= bitpos;
/* Set all the bits above the sign bit. */
- b = (b ^ signmask) - signmask;
-
- b = (b & addrmask) >> bitpos;
+ b = (b ^ ss) - ss;
/* Now we can do the addition. */
sum = a + b;
positive inputs. The test below looks only at the sign
bits, and it really just
SIGN (A) == SIGN (B) && SIGN (A) != SIGN (SUM)
- */
- signmask = (fieldmask >> 1) + 1;
- if (((~ (a ^ b)) & (a ^ sum)) & signmask)
- flag = bfd_reloc_overflow;
+ 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. */
+ if (((~(a ^ b)) & (a ^ sum)) & signmask & addrmask)
+ flag = bfd_reloc_overflow;
break;
case complain_overflow_unsigned:
separate test, we can check for this by or-ing in the
operands when testing for the sum overflowing its final
field. */
- a = (a & addrmask) >> rightshift;
- b = (b & addrmask) >> bitpos;
sum = (a + b) & addrmask;
- if ((a | b | sum) & ~ fieldmask)
+ if ((a | b | sum) & signmask)
flag = bfd_reloc_overflow;
-
- break;
-
- case complain_overflow_bitfield:
- /* Much like the signed check, but for a field one bit
- 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
- overflow, which is exactly what we want. */
- a >>= rightshift;
-
- signmask = ~ fieldmask;
- ss = a & signmask;
- if (ss != 0 && ss != (((bfd_vma) -1 >> rightshift) & signmask))
- flag = bfd_reloc_overflow;
-
- signmask = ((~ howto->src_mask) >> 1) & howto->src_mask;
- 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 & addrmask)
- flag = bfd_reloc_overflow;
-
break;
default:
BFD_RELOC_386_TLS_DTPOFF32
ENUMX
BFD_RELOC_386_TLS_TPOFF32
+ENUMX
+ BFD_RELOC_386_TLS_GOTDESC
+ENUMX
+ BFD_RELOC_386_TLS_DESC_CALL
+ENUMX
+ BFD_RELOC_386_TLS_DESC
ENUMDOC
i386/elf relocations
BFD_RELOC_X86_64_GOTOFF64
ENUMX
BFD_RELOC_X86_64_GOTPC32
+ENUMX
+ BFD_RELOC_X86_64_GOTPC32_TLSDESC
+ENUMX
+ BFD_RELOC_X86_64_TLSDESC_CALL
+ENUMX
+ BFD_RELOC_X86_64_TLSDESC
ENUMDOC
x86-64/elf relocations
Thumb 22 bit pc-relative branch. The lowest bit must be zero and is
not stored in the instruction. The 2nd lowest bit comes from a 1 bit
field in the instruction.
+ENUM
+ BFD_RELOC_ARM_PCREL_CALL
+ENUMDOC
+ ARM 26-bit pc-relative branch for an unconditional BL or BLX instruction.
+ENUM
+ BFD_RELOC_ARM_PCREL_JUMP
+ENUMDOC
+ ARM 26-bit pc-relative branch for B or conditional BL instruction.
ENUM
BFD_RELOC_THUMB_PCREL_BRANCH7
Relocations used by VAX ELF.
ENUM
- BFD_RELOC_MS1_PC16
+ BFD_RELOC_MT_PC16
ENUMDOC
- Morpho MS1 - 16 bit immediate relocation.
+ Morpho MT - 16 bit immediate relocation.
ENUM
- BFD_RELOC_MS1_HI16
+ BFD_RELOC_MT_HI16
ENUMDOC
- Morpho MS1 - Hi 16 bits of an address.
+ Morpho MT - Hi 16 bits of an address.
ENUM
- BFD_RELOC_MS1_LO16
+ BFD_RELOC_MT_LO16
ENUMDOC
- Morpho MS1 - Low 16 bits of an address.
+ Morpho MT - Low 16 bits of an address.
ENUM
- BFD_RELOC_MS1_GNU_VTINHERIT
+ BFD_RELOC_MT_GNU_VTINHERIT
ENUMDOC
- Morpho MS1 - Used to tell the linker which vtable entries are used.
+ Morpho MT - Used to tell the linker which vtable entries are used.
ENUM
- BFD_RELOC_MS1_GNU_VTENTRY
+ BFD_RELOC_MT_GNU_VTENTRY
ENUMDOC
- Morpho MS1 - Used to tell the linker which vtable entries are used.
+ Morpho MT - Used to tell the linker which vtable entries are used.
ENUM
- BFD_RELOC_MS1_PCINSN8
+ BFD_RELOC_MT_PCINSN8
ENUMDOC
- Morpho MS1 - 8 bit immediate relocation.
+ Morpho MT - 8 bit immediate relocation.
ENUM
BFD_RELOC_MSP430_10_PCREL
}
static reloc_howto_type bfd_howto_32 =
-HOWTO (0, 00, 2, 32, FALSE, 0, complain_overflow_bitfield, 0, "VRT32", FALSE, 0xffffffff, 0xffffffff, TRUE);
+HOWTO (0, 00, 2, 32, FALSE, 0, complain_overflow_dont, 0, "VRT32", FALSE, 0xffffffff, 0xffffffff, TRUE);
/*
INTERNAL_FUNCTION
projects / deliverable / binutils-gdb.git / blobdiff