Hi,

On some x86_64 kernels you will get a trapped event after a step out of
a syscall, but the stepping flag isn't set in that case. This is at
least the case at least on 2.6.18-8.1.6.el5, but not on any of the
Fedora kernels I ever tested with, currently 2.6.20-1.2962.fc6.

Luckily the Isa has a way to signal such an event and this patch updates
the X86_64 Isa as follows to handle this:

2007-07-06  Mark Wielaard  <mwielaard@redhat.com>

    * IsaX8664.java hasExecutedSpuriousTrap): Check for SYSCALL
    instruction.

This makes the following testcases PASS on such kernels and doesn't
change the results on any other system I tested on:

testSteppingtestHitAndRun(frysk.proc.TestBreakpoints) ...PASS
testSteppingtestInsertRemove(frysk.proc.TestBreakpoints) ...PASS
testSteppingAddLots(frysk.proc.TestBreakpoints) ...PASS
testStepSigReturn(frysk.proc.TestTaskObserverInstructionSigReturn) ...PASS

Cheers,

Mark