Hi, On Fri, 2009-07-31 at 16:10 +1000, David Gibson wrote: > On Mon, Jul 27, 2009 at 05:41:52AM +0530, K.Prasad wrote: > > Hi David, > > I'm back with a new version of patches after a brief hiatus! > > > > After much deliberation about modifying the code to change the timing of > > signal > > delivery to user-space, it has been decided to retain the existing behaviour > > i.e. SIGTRAP delivered to user-space after execution of causative > > instruction > > although exception is raised before execution of it. > > Ok. Except, presumably for ptrace, since changing that would break > gdb.
Yes. GDB works with some assumptions in mind. Hardware breakpoints (they're not supported right now) trigger before execution, then GDB just removes them and stepi's until we're past the breakpoint. As for HW watchpoints, we always stop before execution (by ppc design presumably). GDB will check the value before the trigger, remove the HW watch, stepi it, and will check the value again to see if it has changed. If we're to trigger after the data load/store has happened, we could have breakage in GDB. Regards, Luis _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
