Re: New test failures - observer.exp, sigaltstack.exp, siginfo.exp

[Andrew Cagney <cagney@gnu.org>]

(assume I managed to get them to pass on at least one system :-)

> sigaltstack.exp fails like this:
> 
> finish
> Run till exit from #0  catcher (signal=26) at /opt/src/gdb/src/gdb/testsuite/gdb.base/sigaltstack.c:71
> Warning:
> Cannot insert breakpoint 0.
> Error accessing memory address 0xffffe420: Input/output error.
> (gdb) FAIL: gdb.base/sigaltstack.exp: finish from catch LEAF
> 
> The problem is that the signal trampoline is read-only.  We can't set
> software breakpoints there.  I suspect there is no way to do this portably.
> Should we skip it instead, i.e. finish right to the place where the signal
> was raised?

Kernel bug.  Two fixes:

- the kernel gets fixed to allow writes to this page -> it should be no 
different to other read-only text sections

- we modify GDB to, when it can't set a return breakpoint, single-step 
out of the problem

> siginfo.exp fails like this:
> (gdb) PASS: gdb.base/siginfo.exp: continue to stepi handler
> bt
> #0  handler (sig=26, info=0xbfffeda0, context=0xbfffee20) at /opt/src/gdb/src/gdb/testsuite/gdb.base/siginfo.c:31
> #1  <signal handler called>
> #2  main () at /opt/src/gdb/src/gdb/testsuite/gdb.base/siginfo.c:66
> (gdb) PASS: gdb.base/siginfo.exp: backtrace for nexti
> step
> 32      } /* handler */
> 1: x/i $pc  0x8048411 <handler+13>:     pop    %ebp
> (gdb) step
> 
> Program exited normally.
> (gdb) FAIL: gdb.base/siginfo.exp: step out of handler
> 
> I don't know if this is currently expected, or what.  It seems like a
> bug.

This worked on my test PPC system, I'll kfail it conditional on 
GNU/Linux i386.

> observer.exp fails like this:
> 
> call observer_notify_normal_stop ()
> too few arguments in function call
> (gdb) PASS: gdb.gdb/observer.exp: sending notification (one observer)
> 
> Then all the counters are wrong, since the function call didn't happen. 
> That's definitely a problem in the test script, since observer_notify_normal_stop
> takes an argument; is this not a fatal condition on some other target?

Unfortunatly my PPC observer tests were already failing, joel's fixed it :-(

Andrew