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> } > > Because _TLF_OOBTRAP is set and because we are still oob, we just leave the kernel without calling __oob_trap_notify and subsequently our clean up code. > This results in re-execution of the same ud2 again and again. > > I fixed it for me in the following way: > > --- a/arch/x86/kernel/traps.c > +++ b/arch/x86/kernel/traps.c > @@ -414,8 +414,9 @@ DEFINE_IDTENTRY_RAW(exc_invalid_op) > handle_invalid_op(regs); > instrumentation_end(); > irqentry_exit(regs, state); > - mark_trap_exit_raw(X86_TRAP_UD, regs); > } > + > + mark_trap_exit_raw(X86_TRAP_UD, regs); > } > > I am not sure it this is a valid way to fix this issue. > If it is, I could work up a patch next week that addresses all the places where this problem could trigger. > > What do you think? > Good catch. Looking at my old x86 patch, I was calling mark_trap_exit in all cases as well. Still, we should check what happens here if it is semantically correct. When I look at __oob_trap_unwind which is now being call for both exits, it contains the surely desired clearing of _TLF_OOBTRAP but also the invocation of the handle_oob_trap_exit. That is harmless for Xenomai as we don't use it, but maybe it is not desired. Philippe needs to comment on this. Jan -- Siemens AG, Technology Competence Center Embedded Linux