Hi,

This patch solves a couple of issues with stepping a breakpoint while a
signal becomes pending (in particular bug #4747 and #4889). Most of the
patch is the addition of new tests based on funit-raise.S, modeled after
funit-symbols.S, that contains several ways of raising an signal from an
instruction on which a breakpoint has been put (divde by zero, illegal
address, illegal instruction, syscall raising a terminating or ignored
signal), this complements some earlier tests written (and now enabled
with this patch) that raise an signal externally or through frysk-core
(testCodeSignalInterrupt and testInstallCodeDuringCode).

When an event interrupts our breakpoint stepping we now abort and reset
the Breakpoint if it happened before the step or finish it if it
happened after the step before handling the event. The code is pretty
conservative in reverting everything related to the breakpoint step
setup. This is necessary because we are mostly using reset stepping, so
we want to set the breakpoint instruction back quickly, or other tasks
that are still running could miss it, and in the case of out of line
stepping we currently only have one out of line address available, so we
need to return it to the Proc immediately so other tasks can use it (or
a new breakpoint in this task is hit through the signal handler for
example).

frysk-core/frysk/proc/ChangeLog
2007-08-15  Mark Wielaard  <mwielaard@redhat.com>
 
    * getSetupAddress (getSetupAddress): New method.
    (stepAbort): Likewise.
    * TestTaskObserverCode.java (testCodeSignalInterrupt): Enable test.
    (testInstallCodeDuringCode): Likewise.
    (Symbol): New static helper class.
    (getGlobalLabelAddress): New helper method.
    (breakTest): New test harness for funit-raise.
    (testBreakDivZero): New test based on breakTest.
    (testBreakIllegalAddress): Likewise.
    (testBreakIllegalInstruction): Likewise.
    (testBreakSignalTerminate): Likewise.
    (testBreakSignalIgnore): Likewise.
    (AttachedObserver.task): New field.
    (updateAttached): Set task field.
    (TerminatingObserver.task): New field.
    (TerminatingObserver.signal): Likewise.
    (TerminatingObserver.value): Likewise.
    (TerminatingObserver.updateTerminating): Set new fields.

frysk-core/frysk/proc/live/ChangeLog
2007-08-15  Mark Wielaard  <mwielaard@redhat.com>

    * LinuxTaskState.java (Stepping.handleTrappedpEvent): Always check
    steppingBreakpoint.
    (checkBreakpointStepping): New helper method.
    (handleSignaledEvent): Use checkBreakpointStepping before
    continuing.
    (handleStoppedEvent): Likewise.

frysk-core/frysk/pkglibdir/ChangeLog
2007-08-15  Mark Wielaard  <mwielaard@redhat.com>

    * funit-raise.S: New test.

Tested on x86_64 kernel 2.6.20 and 2.6.22 (fc6) and x86 kernel
2.6.20-xen and 2.6.22 (f7) both dual core machines. There were no
regressions, but there are currently a lot of failures on both
architectures which make comparisons of test results somewhat hard. So
please let me know if you think this broke something for you.

Cheers,

Mark