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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
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Subject: Re: [FYI][PATCH] tracing/treewide: Remove second parameter of
 __assign_str()
Message-ID: <20240223154532.76475d82@gandalf.local.home>
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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';				\