From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-172.mta1.migadu.com (out-172.mta1.migadu.com [95.215.58.172]) (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 8EDCA221FCC for ; Mon, 22 Sep 2025 07:22:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758525744; cv=none; b=bqy5piQih88QEbBp7iakyG1CJoZKrqx668vvAQFrSOraTORTjRt9ngoqti72SlV9IHgS26PqISFOXVXFRqfn44C+KFp4reJA+obaT9uFwIqaWPWPPIi8IpwG65Gz/uWGCguCau+30fa81Bzdl/vEA+YgTkPIHRlIALMlRRK7L00= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758525744; c=relaxed/simple; bh=euK4RO5zUm6QVrpPQhkpDL82zcRqCjyUf43cQAFA3vg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=XHN8Wbin1NDc84z96DVGmMB1xNCOoSsfEYMATgN0+YsX089mIUvEiOKTub7pDRLWTchPZB0PwanYWWZFXn5PG7XnhpfR/BhATRnuz8kKpY75p85BEkybup/2JcUTJkTtrAyce/HxplNEEWHeMXuDASc3SxHuTsgEs9Iz9HG1fj4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=OgDKT/Lp; arc=none smtp.client-ip=95.215.58.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="OgDKT/Lp" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1758525727; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=J9OQzHaPNzYm7juBZ16CcNou5B+kBw4zgt0pq74WgRg=; b=OgDKT/LpgkQkAdEtUkE0M8mhN791q8lkoNCkEF7hRB9rnCndl6kvDLeg8YHOKpLf/aWkl/ EiepyWK3fxehbBO3gdKDvVLFUZK0JKKB1Op/S1X/4l7wZ0PhL+vSOkaWIQmF3Iy0UZzC9R CmnB89/ITBukVckDVQAW/5IEto4kETM= From: Menglong Dong To: Peter Zijlstra Cc: Alexei Starovoitov , Jiri Olsa , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , X86 ML , "H. Peter Anvin" , Kees Cook , Sami Tolvanen , Mike Rapoport , Andy Lutomirski , Masami Hiramatsu , Alexei Starovoitov , Andrii Nakryiko , LKML , bpf Subject: Re: [PATCH] x86/ibt: make is_endbr() notrace Date: Mon, 22 Sep 2025 15:21:58 +0800 Message-ID: <2384581.ElGaqSPkdT@7940hx> In-Reply-To: <20250922071911.GQ3245006@noisy.programming.kicks-ass.net> References: <20250918120939.1706585-1-dongml2@chinatelecom.cn> <6196970.lOV4Wx5bFT@7940hx> <20250922071911.GQ3245006@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" X-Migadu-Flow: FLOW_OUT On 2025/9/22 15:19 Peter Zijlstra write: > On Mon, Sep 22, 2025 at 03:13:38PM +0800, menglong.dong@linux.dev wrote: > > > > Anyway, I don't mind making is_endbr() invisible to tracing, that might > > > just have security benefits too. But I think first the ftrace folks need > > > to figure out how to best kill that recursion, because I don't think > > > is_endbr is particularly special here. > > > > So, does this patch seem useful after all? > > The use lies in making it harder to find/manipulate endbr things. > > > OK, I'll send a V2 base on your following suggestion. > > Hold off until Masami/Steve have fixed the ftrace recursion issue. After > that we can do this. OK! > >