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[Will Dietz <willdtz AT gmail.com>]

It's my understanding that SAFECode makes no guarantees about the
state of the program after an error.  After all, how do you continue
execution of a program that contains illegal operations?  Not just
aborting the program is something we do to be nice :).

That said in your particular use-case here's what's happening:

SAFECode detects the load/store error before it happens, this is the
first error.  Then SAFECode returns to the code to execute the next
instruction...which is the load/store that we already know is invalid.
 From there we just spin: segfault fires the signal handler which
reports the error (not sure why it's categorized the way it is,
perhaps John can comment), and in good signal handler fashion returns
to the instruction we were executing when the signal was fired...
which is the same instruction that segfaulted... and the signal
handler is called.... and so on.

Hope this helps!

~Will

On Sun, Aug 28, 2011 at 10:16 PM, Matthew Wala 
<wala1 AT illinois.edu>
 wrote:
> Hi everyone:
> The most recent version of SAFECode is giving me trouble with very
> simple test cases.
>
> For instance, the program
>
> int main()
> {
>  int i[100];
>  i[101] = 10;
>  return 0;
> }
>
>
> when instrumented and run results in the following output:
>
> SAFECode:Violation Type 0x6 when accessing  0x617934 at IP=0x401fc0
>
> =======+++++++    SAFECODE RUNTIME ALERT +++++++=======
> = Error type                            :       Load/Store Error
> = Faulting pointer                      :       0x617934
> = Program counter                       :       0x401fc0
> = Fault PC Source                       :       main:6
> =
> = Object allocated at PC                :       0x401ef4
> = Allocated in Source File              :       main:1
> = Object allocation sequence number     :       1
> = Object start                          :       0x6177a0
> = Object length                         :       0x64
> SAFECode: Fault!
> SAFECode:Violation Type 0x9 when accessing  0xc0000001 at IP=0x411b64
>
> =======+++++++    SAFECODE RUNTIME ALERT +++++++=======
> = Error type                            :       Uninitialized/NULL Pointer 
> Error
> = Faulting pointer                      :       0xc0000001
> = Program counter                       :       0x411b64
> = Fault PC Source                       :       <unknown>:0
> SAFECode: Fault!
> SAFECode:Violation Type 0x9 when accessing  0xc0000001 at IP=0x411b64
>
> =======+++++++    SAFECODE RUNTIME ALERT +++++++=======
> = Error type                            :       Uninitialized/NULL Pointer 
> Error
> = Faulting pointer                      :       0xc0000001
> = Program counter                       :       0x411b64
> = Fault PC Source                       :       <unknown>:0
> SAFECode: Fault!
> SAFECode:Violation Type 0x9 when accessing  0xc0000001 at IP=0x411b64
>
> The last Unitialized / NULL Pointer Error statement is repeated without end.
> Is there an explanation for this behavior and how can I get it to work 
> properly?
>
> Thanks,
> Matt
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