On 1/29/08, Ananth N Mavinakayanahalli <[EMAIL PROTECTED]> wrote: > > May be I'm completely off the mark here, but shouldn't a small subset > > of this section simply be 'breakpoint-free' rather than 'kprobe-free'? > > Placing a breakpoint on kprobe_handler (say) can loop into a recursive > > trap without allowing the debugger's notifier chain to be invoked. > > A well heeled debugger will necessarily take care of saving contexts > (using techniques like setjmp/longjmp, etc) to help it recover from such > nested cases (See xmon for example).
Ok, but the protection/warning is not just for xmon. > > I'm assuming that non-kprobe exception notifiers may (or even should) run > > after kprobe's notifier callback (kprobe_exceptions_notify). > > Yes, any such notifier is invoked after kprobe's callback as the kprobe > notifier is always registered with the highest priority. Ok. > > The WARN_ON (and not a BUG_ON) will be hit iff: > > (in_kprobes_functions(addr) && !is_jprobe_bkpt(addr)) > > But that still is unneeded dmesg clutter, IMHO. Ok, a warning in my opinion would've been prudent since I think we cannot guarantee non kprobe breakpoint users (debuggers or anything else) from the recursive trap handling case. > Ananth -- Thanks, Abhishek -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
