On 12/17, Roland McGrath wrote: > > Comparing to the old (2.6.32) logic, I think it might be this (untested). > I also note this is the sole use of get_si_code, seems like it should > just be rolled in here.
Well, it is too late for me to even try to read this patch ;) but... > @@ -569,14 +568,15 @@ dotraplinkage void __kprobes do_debug(struct pt_regs > *regs, long error_code) > * We already checked v86 mode above, so we can check for kernel mode > * by just checking the CPL of CS. > */ > + dr6 = tsk->thread.debugreg6; why? we have "tsk->thread.debugreg6 = dr6" above > if ((dr6 & DR_STEP) && !user_mode(regs)) { > tsk->thread.debugreg6 &= ~DR_STEP; > set_tsk_thread_flag(tsk, TIF_SINGLESTEP); > regs->flags &= ~X86_EFLAGS_TF; this looks strange... we set TIF_SINGLESTEP but clear X86_EFLAGS_TF > + } else if (dr6 & (DR_STEP | DR_TRAP_BITS)) { > + send_sigtrap(tsk, regs, error_code, get_si_code(dr6)); > } > - si_code = get_si_code(tsk->thread.debugreg6); > - if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS)) > - send_sigtrap(tsk, regs, error_code, si_code); > + can't understand how this change can fix the problem. We should always send SIGTRAP if the task returns to user-mode with X86_EFLAGS_TF? OK. I blindly applied this patch, step-simple still fails. Oleg.