On 10/06, Jan Kratochvil wrote: > > On Tue, 06 Oct 2009 19:14:28 +0200, Oleg Nesterov wrote: > > On 10/06, Jan Kratochvil wrote: > [...] > > > If it is not reported to the new tracer then it will be always > > > processed by the tracee, is it right? > > > > Yes, sure. > > > > (But, just in case... if the tracer does ptrace(DETACH, SIGNR), this > > signr only matters if the tracee was stopped after reporting syscall > > or signal, otherwise SIGNR is ignored). > > In which specific cases SIGNR can get ignored? > > Whole PTRACE_DETACH will be ignored if the tracee is not stopped. > It SIGNR will be proabably ignored if the tracee is now dead. > Otherwise SIGNR should get delivered, shouldn't it?
No (afaics). For example, the tracee reports PTRACE_EVENT_EXEC and stops. In this case SIGNR has no effect after PTRACE_CONT/DETACH/etc. SIGNR does not ignored after the tracee reported syscall entry/exit or signal. If you think this should be changed, please tell. As always, I do not know if it was supposed or not. (and in fact I should re-check my understanding after sleep). > > > + /* SIGPIPE was still pending and it has not been yet delivered. */ > > > + if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGPIPE) > [...] > > Yes, I didn't verify this yet, but I think with this patch the > > test-case should succeed with utrace-ptrace kernel. > > Checked-in. Thanks! Oleg.
