From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753169Ab1CEKit (ORCPT ); Sat, 5 Mar 2011 05:38:49 -0500 Received: from mail-fx0-f46.google.com ([209.85.161.46]:61048 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752658Ab1CEKhS (ORCPT ); Sat, 5 Mar 2011 05:37:18 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; b=q9YxEbLlukFw5ZvdKdBQPL639LfRaYOi0wX8Ts6+pG0gF9Q44l4B2Zo1ZXjrZBMGe6 y57FVE0V5m3V6L9rFLizKCG2OhFlhl3JcPtlNBFyNNNF59SysUTnSwpjO114Wnhac4Ey U61Qk4kd98ekoFHeR0V1oRCrE+xNN0m37mDIU= From: Tejun Heo To: oleg@redhat.com, roland@redhat.com, jan.kratochvil@redhat.com, vda.linux@googlemail.com Cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, indan@nul.nu, Tejun Heo Subject: [PATCH 02/10] ptrace: remove the extra wake_up_state() from ptrace_detach() Date: Sat, 5 Mar 2011 11:36:59 +0100 Message-Id: <1299321427-15051-3-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1299321427-15051-1-git-send-email-tj@kernel.org> References: <1299321427-15051-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This wake_up_state() has a turbulent history. This is a remnant from ancient ptrace implementation and patently wrong. Commit 95a3540d (ptrace_detach: the wrong wakeup breaks the ERESTARTxxx logic) removed it but the change was reverted later by commit edaba2c5 (ptrace: revert "ptrace_detach: the wrong wakeup breaks the ERESTARTxxx logic") citing compatibility breakage and general brokeness of the whole group stop / ptrace interaction. Then, recently, it got converted from wake_up_process() to wake_up_state() to make it less dangerous. Digging through the mailing archives, the compatibility breakage doesn't seem to be critical in the sense that the behavior isn't well defined or reliable to begin with and it seems to have been agreed to remove the wakeup with proper cleanup of the whole thing. Now that the group stop and its interaction with ptrace are being cleaned up, it's high time to finally kill this silliness. Signed-off-by: Tejun Heo Acked-by: Oleg Nesterov Cc: Roland McGrath --- kernel/ptrace.c | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) diff --git a/kernel/ptrace.c b/kernel/ptrace.c index e2302e4..6acf895 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -312,8 +312,6 @@ static int ptrace_detach(struct task_struct *child, unsigned int data) if (child->ptrace) { child->exit_code = data; dead = __ptrace_detach(current, child); - if (!child->exit_state) - wake_up_state(child, TASK_TRACED | TASK_STOPPED); } write_unlock_irq(&tasklist_lock); -- 1.7.1