Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934086AbaDIRGP (ORCPT ); Wed, 9 Apr 2014 13:06:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:28324 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933342AbaDIRGL (ORCPT ); Wed, 9 Apr 2014 13:06:11 -0400 Date: Wed, 9 Apr 2014 19:06:16 +0200 From: Oleg Nesterov To: Steven Rostedt Cc: Mathieu Desnoyers , Frederic Weisbecker , LKML , Andrew Morton , Ingo Molnar Subject: [PATCH RESEND 2/2] tracing: syscall_regfunc() should not skip kernel threads Message-ID: <20140409170616.GC27638@redhat.com> References: <1397059882-23063-1-git-send-email-fweisbec@gmail.com> <1397059882-23063-3-git-send-email-fweisbec@gmail.com> <360091921.1294.1397060915052.JavaMail.zimbra@efficios.com> <20140409124249.4081e665@gandalf.local.home> <20140409170505.GA27638@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140409170505.GA27638@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org syscall_regfunc() ignores the kernel thread because "it has no effect", see cc3b13c1 "Don't trace kernel thread syscalls". However, this means that a user-space task spawned by call_usermodehelper() won't report the system calls if kernel_execve() is called when sys_tracepoint_refcount != 0. Remove this check. Hopefully the unnecessary report from ret_from_fork path mentioned by cc3b13c1 is fine. In fact "this is the only case" is not true. Say, kernel_execve() itself does "int 80" on X86_32. Hopefully fine too. Signed-off-by: Oleg Nesterov --- kernel/tracepoint.c | 4 +--- 1 files changed, 1 insertions(+), 3 deletions(-) diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index a16754b..4e1e4ca 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -737,9 +737,7 @@ void syscall_regfunc(void) if (!sys_tracepoint_refcount) { read_lock(&tasklist_lock); do_each_thread(g, t) { - /* Skip kernel threads. */ - if (!(t->flags & PF_KTHREAD)) - set_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT); + set_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT); } while_each_thread(g, t); read_unlock(&tasklist_lock); } -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/