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 B09892063FD; Wed, 19 Mar 2025 12:19:02 +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=1742386742; cv=none; b=oEGmxxWp7sIlXXQGSp5dmrk6xjUgdp2x3tADBddPHrJHFe5IuDmq8t8UqOfvga+79CQ+MosAHvO2k60dSXuvLZHSctXGg1RWcPvRkXyEuG2RIa0N3QA86BaTVw5JCMysHvxYBstKW471K6tDXPKSQnozBPQij2gvPAWPvOn36Uo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742386742; c=relaxed/simple; bh=jNNUx9ca2/ZhLS8cRJR2eUc4p4bV+bOteziGYAE80x4=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=OREfUkMMhuLxdgaEFaXKzoVI1mGtX1iK8+hH/C9VYk0vKjg8kdnobYVLVnrvHjnc1SIyRY3mHtqEAVcCWbGmYZCNqdzOg+UY2bqIEYC3ybDcEUFm8yv+m/BZUDsA1MLaYbY9df8P2eiZAH1HJl5FQFDqtP7I/DuHJTSISLadoWE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KBIdGifu; 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="KBIdGifu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 506DBC4CEEE; Wed, 19 Mar 2025 12:19:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742386742; bh=jNNUx9ca2/ZhLS8cRJR2eUc4p4bV+bOteziGYAE80x4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=KBIdGifugnvdPgIU59FqNeB7xa4AJ0cuGvNMKSoRQPyYwgpsFwecgO1pHhQxPAx+c qVvhz0Y0IKYyAY10vYac41olE8Jc0og59JgRLEGMEsYosmjuOYkaEclf9dqMVxwGmI MQaodSdm4ESHYWJinQ2tWPnRw9VArjDeUT+upvza16cRcdFYCNZz1LpZVV8XKJlEM4 uL/WVQZRbF9KF9SdVbmp4Aoi8mnBy88XXGBBuNnGHGUm+XTuciH//FkPhQGOqE9C+P d0//ixFnVwxBtMiVls8Oms1aruNaYRQENPjkZzPvLTQHFLzctfCGnXstCIQtyBd2Sr 9Fwk07wTS5SGw== Date: Wed, 19 Mar 2025 21:18:58 +0900 From: Masami Hiramatsu (Google) To: Douglas RAILLARD Cc: rostedt@goodmis.org, Masami Hiramatsu , Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH] tracing: Fix synth event printk format for str fields Message-Id: <20250319211858.6d8166e3fb202e6e5a658557@kernel.org> In-Reply-To: <20250318180939.227696-1-douglas.raillard@arm.com> References: <20250318180939.227696-1-douglas.raillard@arm.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Hi, On Tue, 18 Mar 2025 18:09:38 +0000 Douglas RAILLARD wrote: > From: Douglas Raillard > > The printk format for synth event uses "%.*s" to print string fields, > but then only passes the pointer part as var arg. > > Add the missing precision var arg. I'm not sure what you want to. Would you mean showing the string length too? But I think actual output(*) shows only string, right? (*) the output data which can be read from `trace` file. Thank you, > > Signed-off-by: Douglas Raillard > --- > kernel/trace/trace_events_synth.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c > index e3f7d09e5512..274b9b1d9f7d 100644 > --- a/kernel/trace/trace_events_synth.c > +++ b/kernel/trace/trace_events_synth.c > @@ -620,7 +620,8 @@ static int __set_synth_event_print_fmt(struct synth_event *event, > if (event->fields[i]->is_string && > event->fields[i]->is_dynamic) > pos += snprintf(buf + pos, LEN_OR_ZERO, > - ", __get_str(%s)", event->fields[i]->name); > + ", (int)__get_dynamic_array_len(%s), __get_str(%s)", > + event->fields[i]->name, event->fields[i]->name); > else if (event->fields[i]->is_stack) > pos += snprintf(buf + pos, LEN_OR_ZERO, > ", __get_stacktrace(%s)", event->fields[i]->name); > -- > 2.43.0 > -- Masami Hiramatsu (Google)