From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 9E84F30FC0A for ; Tue, 18 Nov 2025 09:12:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763457164; cv=none; b=iSAxMwYtIyqlqp1wMFD16bVl4dUaa0Ow4/+uxaMu37HQPM6GVJDYec05cjHEux/XrgzEbNJpFPKpsngiPW18MfGFjeejYzna89b/XnGWul2lvQ6gZaIc/Xf0qCuPhjvbWiR3d7RvUu1rsbro1u8PEF2DYPAowY+1wNfkAh1e4c0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763457164; c=relaxed/simple; bh=yOA+dKTHmHIEHYwJCa9JxvCem0HogKDKTk0d5iDZ4MM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cgVSFxN6OOcd1YTxPiT+F4iDZB4N9Xr9h77eIWyEXlV5mSQW/GL9ikZGVJJiTM93slg7YGK8Zp2SepX0uzdBfRqwA1RcJjHzyx4iFQF6i/FX74F76+zp6IdenwLQwTejZwF9ErVTKVoMHFTQ9dI8TBK8Aas5x+L9jRBS21gBafI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=pAROWkdJ; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="pAROWkdJ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=137JkEcJwFFS8JdsdEHMfTr9qiwp/OkKL4jsifjupIE=; b=pAROWkdJf4lycByZbkDEqHlxnD hCaXIVq69dDHvCoF0UeQusGK+C8yurct014oDC16YT6EMcYctIslqFjz7rfCwB9W2B7rbqkTPyWIA JzXLjSPct0kctkfqb7yv5CXQUWg917Yz670+wlpFJ1JOeHS4fzLhSGM12bOUEEB+sVynRdzlBZHt/ QdTOPbdHGautZqVj+0dlDQAfsj1joaBfkbnJaICaYQGZUNNezbxiizdoHPtOXmvd6cTmkArAlsu7c u42wjOHSP6kJu9kXCzPP0LibuXNYu73r1Lhh9ZxrvtTvlSqoAHw/qW3OJUfeN+i5cw7/3kZ6fJEva yjYax+Rw==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vLHlO-0000000FF1j-1Pn8; Tue, 18 Nov 2025 09:12:38 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 61C8C300342; Tue, 18 Nov 2025 10:12:37 +0100 (CET) Date: Tue, 18 Nov 2025 10:12:37 +0100 From: Peter Zijlstra To: Alexandre Chartre Cc: David Laight , Josh Poimboeuf , linux-kernel@vger.kernel.org, mingo@kernel.org Subject: Re: [PATCH v4 00/28] objtool: Function validation tracing Message-ID: <20251118091237.GM3245006@noisy.programming.kicks-ass.net> References: <3367da83-16b7-4c6a-bd08-d14ec4067025@oracle.com> <20251117094210.3c3e4f40@pumpkin> <81693206-9002-4669-ab74-fda3d31c25bb@oracle.com> <20251117123729.72ffa3e2@pumpkin> <3673c975-dc51-47ea-940b-8f09afa213a5@oracle.com> <20251117220953.4f7bccc7@pumpkin> <6bc8722e-f84b-427e-96ad-6e0c3907bd09@oracle.com> 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-Disposition: inline In-Reply-To: <6bc8722e-f84b-427e-96ad-6e0c3907bd09@oracle.com> On Tue, Nov 18, 2025 at 08:19:14AM +0100, Alexandre Chartre wrote: > In that specific case, they are not executed, they are after a jump: > > 82e7: __switch_to_asm+0x27 > = DEFAULT > 82e7: __switch_to_asm+0x27 | jmp 0x8312 <__switch_to_asm+0x52> > 82e9: __switch_to_asm+0x29 | NOP41 nop41 is a bit naf since x86 can only have 15 byte instructions :-)