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 931CC212D7C; Mon, 20 Apr 2026 23:57:28 +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=1776729448; cv=none; b=rPNOa4cR4+QeznOtH6i8bmakZaeQkO1WuAq78IljZobulML53KufMqbbXFl13u6LcQWHkKwoTWJz57EX3l/dPf2F/MYBs1GzgUeSHBz2tqDKWkIPlNK+tQjj/d+7uZdzd7WcH5m2YlRhuk7TQsc3Swn+BBzMkcdOD0AFyZpmzLo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776729448; c=relaxed/simple; bh=SgbK2Ycca8ktwcDxfzwexeOL/UiqLEfnnFekZIG/eLA=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=f2M1AvVPYNT/mQH+mDz/rQ5HW0u7jPmi6EK8idSbB+f5wW9/toyBqpe5iHS72yRSLy7cL6/5DfPLyHb4UoS54UNDy/ZI3mkLYpnhTaa/hI2PridfyaXM1CpkTcCVVeog2aft6taoGVMsSXnlAIkekdN11+A00EkVsC8LsUFFZWI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=P1VWzgzh; 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="P1VWzgzh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C76C4C19425; Mon, 20 Apr 2026 23:57:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776729448; bh=SgbK2Ycca8ktwcDxfzwexeOL/UiqLEfnnFekZIG/eLA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=P1VWzgzhKoGyzO4Rl1xPscbFQcIMcZuTr4h7e3kz0Q1dpLi/YTYYYnXqL0w56mklI Ar/Y/TGUm3kwesvEEllPzL5Yr8Wq1JZbcndlyeQfx780KRyCmKS7w9w2FhDKA5BC8b CT8GGBU7TXNN27FPdyznccTMWhcxHfoanD2WcRz5jvvHic/wxC01qaIODQeIM5OxUR x4UflF0c1sMZ3J5QP3bzyPZ2gb0cQtwnSFiIrGWGQULg5Cw32wxDXPEh8F628Gu0BE E0mtU9UqzHyvWx3tOkJhiFZN3bLkSMs8wtCUwqxBNvDB5+p0YhrcUobTY5+iOdEb1W 2KVTXxSjfFmnA== Date: Tue, 21 Apr 2026 08:57:25 +0900 From: Masami Hiramatsu (Google) To: Breno Leitao Cc: Steven Rostedt , Mathieu Desnoyers , Ingo Molnar , Frederic Weisbecker , Steven Rostedt , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, paulmck@kernel.org, kernel-team@meta.com Subject: Re: [PATCH] tracing: branch: Fix inverted check on stat tracer registration Message-Id: <20260421085725.4e5c8ebf3a5e0470bab61e4e@kernel.org> In-Reply-To: <20260420-tracing-v1-1-d8f4cd0d6af1@debian.org> References: <20260420-tracing-v1-1-d8f4cd0d6af1@debian.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-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 On Mon, 20 Apr 2026 06:25:09 -0700 Breno Leitao wrote: > init_annotated_branch_stats() and all_annotated_branch_stats() check the > return value of register_stat_tracer() with "if (!ret)", but > register_stat_tracer() returns 0 on success and a negative errno on > failure. The inverted check causes the warning to be printed on every > successful registration, e.g.: > > Warning: could not register annotated branches stats > > while leaving real failures silent. The initcall also returned a > hard-coded 1 instead of the actual error. > > Invert the check and propagate ret so that the warning fires on real > errors and the initcall reports the correct status. > Good catch! Acked-by: Masami Hiramatsu (Google) Thanks, > Fixes: 002bb86d8d42 ("tracing/ftrace: separate events tracing and stats tracing engine") > Signed-off-by: Breno Leitao > --- > kernel/trace/trace_branch.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c > index 6809b370e991d..d1564db95a8f5 100644 > --- a/kernel/trace/trace_branch.c > +++ b/kernel/trace/trace_branch.c > @@ -373,10 +373,10 @@ __init static int init_annotated_branch_stats(void) > int ret; > > ret = register_stat_tracer(&annotated_branch_stats); > - if (!ret) { > + if (ret) { > printk(KERN_WARNING "Warning: could not register " > "annotated branches stats\n"); > - return 1; > + return ret; > } > return 0; > } > @@ -438,10 +438,10 @@ __init static int all_annotated_branch_stats(void) > int ret; > > ret = register_stat_tracer(&all_branch_stats); > - if (!ret) { > + if (ret) { > printk(KERN_WARNING "Warning: could not register " > "all branches stats\n"); > - return 1; > + return ret; > } > return 0; > } > > --- > base-commit: c7275b05bc428c7373d97aa2da02d3a7fa6b9f66 > change-id: 20260420-tracing-3f1367ee4b93 > > Best regards, > -- > Breno Leitao > -- Masami Hiramatsu (Google)