From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B3121215F42; Fri, 14 Nov 2025 14:48:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763131735; cv=none; b=a+tyR7SKuu02CLti1OJMWEeQ1kZSQpJ3cgqZwtvOLahkC5ctho6u1LgrbAOa88+grue7ZcFesXlkHeQeDLxun7bVBnj0trD//hbIL1KDbqxIbdIW17YVp7NTitzZGr4A7YBa2IqMiTkeji1VIeA1QUFc69iGWQtEGhbMuP27kVA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763131735; c=relaxed/simple; bh=2s10Oc3FM2bCGELw8+LPnTQhTxTU08gxxlwc1Kuc6BI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PQWIR1ySqHDAhtSIRHkGAo6kTZBv8xn/ABv0tDNs697yg97hh0Bx4SasODF7HR3ecED7kmU3Ng2WvcMRjRiOv9HkCzjX5huq+KuoJ9J1b62GScJhzlwA8+bGIi9eYZNS28LWAAGAONwKiLH0HvR5yUvrsfZTttfxDFkF2tme6Dc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ouADgnvK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ouADgnvK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C64D6C4CEF8; Fri, 14 Nov 2025 14:48:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763131735; bh=2s10Oc3FM2bCGELw8+LPnTQhTxTU08gxxlwc1Kuc6BI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ouADgnvKSF7mOVcBi/jAXNlaQrN5l7azsWIAM9V2tbLN8klB/I25l2yfa6jkzwPz+ RvJY5lyPi8/rTr241IsfGbEshDCidpGufl/lRJCUVfPzN/Sk4ZKdIQcLHbDytDs4lL cKQ0vihrsyPoqkgbuF9io5KYeNgBLDwhYavKQVdz53LobuOg0Xy3IAtWK/gkCnKY/Y i1Aqjs5+QE+xCgq0FTLZdigbsIOUYgfGkREScme8LZriDFWiSiUr8b8RMSuhGZAsQu a7BOqizCoXEZSVKo3atDzZkTAEDn8LFts/27Dz3daeSNDeJENTIQEkAtBYpkvyGyrR czLrvnMifK/ew== Date: Fri, 14 Nov 2025 15:48:52 +0100 From: Frederic Weisbecker To: Steven Rostedt Cc: Stephen Rothwell , "Paul E. McKenney" , Neeraj Upadhyay , Boqun Feng , Uladzislau Rezki , Masami Hiramatsu , Linux Kernel Mailing List , Linux Next Mailing List , Sebastian Andrzej Siewior Subject: Re: linux-next: manual merge of the rcu tree with the ftrace tree Message-ID: References: <20251114135226.64831207@canb.auug.org.au> <20251114074255.3e535084@gandalf.local.home> Precedence: bulk X-Mailing-List: linux-next@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20251114074255.3e535084@gandalf.local.home> Le Fri, Nov 14, 2025 at 07:42:55AM -0500, Steven Rostedt a écrit : > On Fri, 14 Nov 2025 13:52:26 +1100 > Stephen Rothwell wrote: > > > Hi all, > > > > Today's linux-next merge of the rcu tree got a conflict in: > > > > kernel/trace/trace_syscalls.c > > > > between commit: > > > > a544d9a66bdf ("tracing: Have syscall trace events read user space string") > > > > from the ftrace tree and commit: > > > > 35587dbc58dd ("tracing: Guard __DECLARE_TRACE() use of __DO_TRACE_CALL() with SRCU-fast") > > > > from the rcu tree. > > > > I fixed it up (Maybe - see below) and can carry the fix as necessary. This > > is now fixed as far as linux-next is concerned, but any non trivial > > conflicts should be mentioned to your upstream maintainer when your tree > > is submitted for merging. You may also want to consider cooperating > > with the maintainer of the conflicting tree to minimise any particularly > > complex conflicts. > > Thanks for the update. > > > > > > diff --cc kernel/trace/trace_syscalls.c > > index e96d0063cbcf,3f699b198c56..000000000000 > > --- a/kernel/trace/trace_syscalls.c > > +++ b/kernel/trace/trace_syscalls.c > > @@@ -878,6 -322,8 +890,7 @@@ static void ftrace_syscall_enter(void * > > * buffer and per-cpu data require preemption to be disabled. > > */ > > might_fault(); > > + preempt_rt_guard(); > > - guard(preempt_notrace)(); > > My code made it so that preemption is not needed here but is moved later > down for the logic that does the reading of user space data. > > Note, it must have preemption disabled for all configs (including RT). > Otherwise, the data it has can get corrupted. > > Paul, can you change it so that you *do not* touch this file? Ok, I've zapped the commit for now until we sort this out. Thanks. -- Frederic Weisbecker SUSE Labs