Received-SPF: pass (google.com: domain of linux-nfs+bounces-2069-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
Date: Fri, 23 Feb 2024 15:45:32 -0500
From: Steven Rostedt <rostedt@goodmis.org>
To: Jeff Johnson <quic_jjohnson@quicinc.com>
Cc: LKML <linux-kernel@vger.kernel.org>, Linux Trace Kernel
 <linux-trace-kernel@vger.kernel.org>, Masami Hiramatsu
 <mhiramat@kernel.org>, Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
 Linus Torvalds <torvalds@linux-foundation.org>,
 <linuxppc-dev@lists.ozlabs.org>, <kvm@vger.kernel.org>,
 <linux-block@vger.kernel.org>, <linux-cxl@vger.kernel.org>,
 <linux-media@vger.kernel.org>, <dri-devel@lists.freedesktop.org>,
 <amd-gfx@lists.freedesktop.org>, <intel-gfx@lists.freedesktop.org>,
 <intel-xe@lists.freedesktop.org>, <linux-arm-msm@vger.kernel.org>,
 <freedreno@lists.freedesktop.org>, <virtualization@lists.linux.dev>,
 <linux-rdma@vger.kernel.org>, <linux-pm@vger.kernel.org>,
 <iommu@lists.linux.dev>, <linux-tegra@vger.kernel.org>,
 <netdev@vger.kernel.org>, <linux-hyperv@vger.kernel.org>,
 <ath10k@lists.infradead.org>, <linux-wireless@vger.kernel.org>,
 <ath11k@lists.infradead.org>, <ath12k@lists.infradead.org>,
 <brcm80211@lists.linux.dev>, <brcm80211-dev-list.pdl@broadcom.com>,
 <linux-usb@vger.kernel.org>, <linux-bcachefs@vger.kernel.org>,
 <linux-nfs@vger.kernel.org>, <ocfs2-devel@lists.linux.dev>,
 <linux-cifs@vger.kernel.org>, <linux-xfs@vger.kernel.org>,
 <linux-edac@vger.kernel.org>, <selinux@vger.kernel.org>,
 <linux-btrfs@vger.kernel.org>, <linux-erofs@lists.ozlabs.org>,
 <linux-f2fs-devel@lists.sourceforge.net>, <linux-hwmon@vger.kernel.org>,
 <io-uring@vger.kernel.org>, <linux-sound@vger.kernel.org>,
 <bpf@vger.kernel.org>, <linux-wpan@vger.kernel.org>, <dev@openvswitch.org>,
 <linux-s390@vger.kernel.org>, <tipc-discussion@lists.sourceforge.net>,
 Julia Lawall <Julia.Lawall@inria.fr>
Subject: Re: [FYI][PATCH] tracing/treewide: Remove second parameter of
 __assign_str()
Message-ID: <20240223154532.76475d82@gandalf.local.home>
In-Reply-To: <20240223134653.524a5c9e@gandalf.local.home>
References: <20240223125634.2888c973@gandalf.local.home>
	<0aed6cf2-17ae-45aa-b7ff-03da932ea4e0@quicinc.com>
	<20240223134653.524a5c9e@gandalf.local.home>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit

On Fri, 23 Feb 2024 13:46:53 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:

> Now one thing I could do is to not remove the parameter, but just add:
> 
> 	WARN_ON_ONCE((src) != __data_offsets->item##_ptr_);
> 
> in the __assign_str() macro to make sure that it's still the same that is
> assigned. But I'm not sure how useful that is, and still causes burden to
> have it. I never really liked the passing of the string in two places to
> begin with.

Hmm, maybe I'll just add this patch for 6.9 and then in 6.10 do the
parameter removal.

-- Steve

diff --git a/include/trace/stages/stage6_event_callback.h b/include/trace/stages/stage6_event_callback.h
index 0c0f50bcdc56..7372e2c2a0c4 100644
--- a/include/trace/stages/stage6_event_callback.h
+++ b/include/trace/stages/stage6_event_callback.h
@@ -35,6 +35,7 @@ #define __assign_str(dst, src)
 	do {								\
 		char *__str__ = __get_str(dst);				\
 		int __len__ = __get_dynamic_array_len(dst) - 1;		\
+		WARN_ON_ONCE((src) != __data_offsets.dst##_ptr_); 	\
 		memcpy(__str__, __data_offsets.dst##_ptr_ ? :		\
 		       EVENT_NULL_STR, __len__);			\
 		__str__[__len__] = '\0';				\