From f008faff0e2777c8b3fe853891b774ca465938d8 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Thu, 2 Apr 2009 16:58:02 -0700 Subject: [PATCH] signals: protect init from unwanted signals more (This is a modified version of the patch submitted by Oleg Nesterov http://lkml.org/lkml/2008/11/18/249 and tries to address comments that came up in that discussion) init ignores the SIG_DFL signals but we queue them anyway, including SIGKILL. This is mostly OK, the signal will be dropped silently when dequeued, but the pending SIGKILL has 2 bad implications: - it implies fatal_signal_pending(), so we confuse things like wait_for_completion_killable/lock_page_killable. - for the sub-namespace inits, the pending SIGKILL can mask (legacy_queue) the subsequent SIGKILL from the parent namespace which must kill cinit reliably. (preparation, cinits don't have SIGNAL_UNKILLABLE yet) The patch can't help when init is ptraced, but ptracing of init is not "safe" anyway. Signed-off-by: Sukadev Bhattiprolu Acked-by: Roland McGrath Signed-off-by: Oleg Nesterov Cc: "Eric W. Biederman" Cc: Daniel Lezcano Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-format-patch failed