From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932568Ab1CWKLm (ORCPT ); Wed, 23 Mar 2011 06:11:42 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:50823 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932406Ab1CWKGT (ORCPT ); Wed, 23 Mar 2011 06:06:19 -0400 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=CkF2iwWP5pnyHNPKhvFgU28Y7HHG1SgqAszfzxLJm/DtQMgiwDM/4Ev7tWwcGKG+ck AX5wNIF6PozWAKdNcHiUYim9o9eD0FUeRtto22l4JUldmdtekWjQaIcWAFp4pg3Nk3UI tLsLF05n8L2uatzUjdsmqQQVBZdG83CraJUok= From: Tejun Heo To: oleg@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, roland@hack.frob.com, Tejun Heo , Roland McGrath Subject: [PATCH 04/20] ptrace: Kill tracehook_notify_jctl() Date: Wed, 23 Mar 2011 11:05:50 +0100 Message-Id: <1300874766-12941-5-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1300874766-12941-1-git-send-email-tj@kernel.org> References: <1300874766-12941-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org tracehook_notify_jctl() aids in determining whether and what to report to the parent when a task is stopped or continued. The function also adds an extra requirement that siglock may be released across it, which is currently unused and quite difficult to satisfy in well-defined manner. As job control and the notifications are about to receive major overhaul, remove the tracehook and open code it. If ever necessary, let's factor it out after the overhaul. * Oleg spotted incorrect CLD_CONTINUED/STOPPED selection when ptraced. Fixed. Signed-off-by: Tejun Heo Cc: Oleg Nesterov Cc: Roland McGrath --- include/linux/tracehook.h | 27 --------------------------- kernel/signal.c | 34 ++++++++++++++-------------------- 2 files changed, 14 insertions(+), 47 deletions(-) diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index 3a2e66d..b073f3c 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -469,33 +469,6 @@ static inline int tracehook_get_signal(struct task_struct *task, } /** - * tracehook_notify_jctl - report about job control stop/continue - * @notify: zero, %CLD_STOPPED or %CLD_CONTINUED - * @why: %CLD_STOPPED or %CLD_CONTINUED - * - * This is called when we might call do_notify_parent_cldstop(). - * - * @notify is zero if we would not ordinarily send a %SIGCHLD, - * or is the %CLD_STOPPED or %CLD_CONTINUED .si_code for %SIGCHLD. - * - * @why is %CLD_STOPPED when about to stop for job control; - * we are already in %TASK_STOPPED state, about to call schedule(). - * It might also be that we have just exited (check %PF_EXITING), - * but need to report that a group-wide stop is complete. - * - * @why is %CLD_CONTINUED when waking up after job control stop and - * ready to make a delayed @notify report. - * - * Return the %CLD_* value for %SIGCHLD, or zero to generate no signal. - * - * Called with the siglock held. - */ -static inline int tracehook_notify_jctl(int notify, int why) -{ - return notify ?: (current->ptrace & PT_PTRACED) ? why : 0; -} - -/** * tracehook_finish_jctl - report about return from job control stop * * This is called by do_signal_stop() after wakeup. diff --git a/kernel/signal.c b/kernel/signal.c index f4db769..03d874e 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1727,7 +1727,7 @@ void ptrace_notify(int exit_code) static int do_signal_stop(int signr) { struct signal_struct *sig = current->signal; - int notify; + int notify = 0; if (!sig->group_stop_count) { struct task_struct *t; @@ -1759,19 +1759,16 @@ static int do_signal_stop(int signr) * a group stop in progress and we are the last to stop, report * to the parent. When ptraced, every thread reports itself. */ - notify = sig->group_stop_count == 1 ? CLD_STOPPED : 0; - notify = tracehook_notify_jctl(notify, CLD_STOPPED); - /* - * tracehook_notify_jctl() can drop and reacquire siglock, so - * we keep ->group_stop_count != 0 before the call. If SIGCONT - * or SIGKILL comes in between ->group_stop_count == 0. - */ - if (sig->group_stop_count) { - if (!--sig->group_stop_count) - sig->flags = SIGNAL_STOP_STOPPED; - current->exit_code = sig->group_exit_code; - __set_current_state(TASK_STOPPED); + if (!--sig->group_stop_count) { + sig->flags = SIGNAL_STOP_STOPPED; + notify = CLD_STOPPED; } + if (task_ptrace(current)) + notify = CLD_STOPPED; + + current->exit_code = sig->group_exit_code; + __set_current_state(TASK_STOPPED); + spin_unlock_irq(¤t->sighand->siglock); if (notify) { @@ -1860,14 +1857,11 @@ relock: signal->flags &= ~SIGNAL_CLD_MASK; - why = tracehook_notify_jctl(why, CLD_CONTINUED); spin_unlock_irq(&sighand->siglock); - if (why) { - read_lock(&tasklist_lock); - do_notify_parent_cldstop(current->group_leader, why); - read_unlock(&tasklist_lock); - } + read_lock(&tasklist_lock); + do_notify_parent_cldstop(current->group_leader, why); + read_unlock(&tasklist_lock); goto relock; } @@ -2034,7 +2028,7 @@ void exit_signals(struct task_struct *tsk) if (unlikely(tsk->signal->group_stop_count) && !--tsk->signal->group_stop_count) { tsk->signal->flags = SIGNAL_STOP_STOPPED; - group_stop = tracehook_notify_jctl(CLD_STOPPED, CLD_STOPPED); + group_stop = CLD_STOPPED; } out: spin_unlock_irq(&tsk->sighand->siglock); -- 1.7.1