Skip to content

Commit

Permalink
[RuntimeDyld] Remove relocation bounds check introduced in r208375 (M…
Browse files Browse the repository at this point in the history
…achO only).

We do all of our address arithmetic in 64-bit, and operations involving
logically negative 32-bit offsets (actually represented as unsigned 64 bit ints)
often overflow into higher bits. The overflow check could be preserved by
casting to uint32 at the callsite for applyRelocationValue, but this would
eliminate the value of the check.

The right way to handle overflow in relocations is to make relocation processing
target specific, and compute the values for RelocationEntry objects in the
appropriate types (32-bit for 32-bit targets, 64-bit for 64-bit targets). This
is coming as part of the cleanup I'm working on.

This fixes another i386 regression test.

<rdar://problem/16889891>



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209536 91177308-0d34-0410-b5e6-96231b3b80d8
  • Loading branch information
lhames committed May 23, 2014
1 parent bd62a7a commit bb75e24
Showing 1 changed file with 1 addition and 4 deletions.
5 changes: 1 addition & 4 deletions lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.h
Original file line number Diff line number Diff line change
Expand Up @@ -28,16 +28,13 @@ class RuntimeDyldMachO : public RuntimeDyldImpl {
private:

/// Write the least significant 'Size' bytes in 'Value' out at the address
/// pointed to by Addr. Check for overflow.
/// pointed to by Addr.
bool applyRelocationValue(uint8_t *Addr, uint64_t Value, unsigned Size) {
for (unsigned i = 0; i < Size; ++i) {
*Addr++ = (uint8_t)Value;
Value >>= 8;
}

if (Value) // Catch overflow
return Error("Relocation out of range.");

return false;
}

Expand Down

0 comments on commit bb75e24

Please sign in to comment.