From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 E5A292BD5B6 for ; Mon, 14 Apr 2025 12:56:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744635416; cv=none; b=XNBfomKbOWOmZoSnJ3rV99wFDNuFwSAJp7MN6uNMKsQlDlRbfSLiTPueP4lD9PzzIFk7GLFCgTB9FS9eqwYGlvK1IydC45jTJRXMEp6vwmKjJPXZop0QMyxpMZ47XceZPfIx12Szs141OCMsGkPh/6uDVcK8ir7QAycCSykWDd8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744635416; c=relaxed/simple; bh=4ndoZIQadw0fx/9dfIwynU9KS2mYw03hR5z3re/dctk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Ym+cgUDQhZMEJiikEUi8j28OLD+c0cJTm8+4SxABNLvpe3gV32DJHNGKfM/ICFszLUlbScV0sg8p/yp7KPhLdfVUM6skS6sAMzdpfOG5DOcOBBUQtth5AiNXE5cCfcgA2aYwVwZz6CvEa1XFaINnZM6QnxUNJeq4Lhv1ZUb/Z1U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=KejR72Nb; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KejR72Nb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744635410; 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: in-reply-to:in-reply-to:references:references; bh=VMtlMTzc9ePJmlezuKsazNNqLDwaXztNRY4ZPAIEu+4=; b=KejR72NbnZCbVmUZT7FlHcz9CTKLMli9CFiQDooI+12ZyROtdiQp8qNoJ+7gOQN/Nsu1v9 H8boXQX+Ak016pt0Wk74YZs+iyIo0fE4YOKrar1BWDFafAMEEirJcFPAZC0VKeDerf366a KQIbiblYFJqURBjtQw1WJnHaCDcNk6E= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-484-HHZHfESfMJSQqcHc6uG-SA-1; Mon, 14 Apr 2025 08:56:43 -0400 X-MC-Unique: HHZHfESfMJSQqcHc6uG-SA-1 X-Mimecast-MFC-AGG-ID: HHZHfESfMJSQqcHc6uG-SA_1744635401 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 861591955DCC; Mon, 14 Apr 2025 12:56:41 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.225.114]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 4B4CB180B487; Mon, 14 Apr 2025 12:56:35 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Mon, 14 Apr 2025 14:56:05 +0200 (CEST) Date: Mon, 14 Apr 2025 14:55:59 +0200 From: Oleg Nesterov To: Jiri Olsa Cc: Peter Zijlstra , Ingo Molnar , Andrii Nakryiko , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, x86@kernel.org, Song Liu , Yonghong Song , John Fastabend , Hao Luo , Steven Rostedt , Masami Hiramatsu , Alan Maguire Subject: Re: [PATCHv3 perf/core 1/2] uprobes/x86: Add support to emulate nop instructions Message-ID: <20250414125558.GC28345@redhat.com> References: <20250414083647.1234007-1-jolsa@kernel.org> 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-Disposition: inline In-Reply-To: <20250414083647.1234007-1-jolsa@kernel.org> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On 04/14, Jiri Olsa wrote: > > @@ -840,6 +840,11 @@ static int branch_setup_xol_ops(struct arch_uprobe *auprobe, struct insn *insn) > insn_byte_t p; > int i; > > + /* x86_nops[insn->length]; same as jmp with .offs = 0 */ > + if (insn->length <= ASM_NOP_MAX && > + !memcmp(insn->kaddr, x86_nops[insn->length], insn->length)) > + goto setup; Reviewed-by: Oleg Nesterov