From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3B39EC4345F for ; Mon, 15 Apr 2024 17:02:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=7cAyEnQASjUsBjea8BrIM6lBAJ9HewyI7cDvejDl3/M=; b=lkjkar5jP+ztg9 L/jGFkfnTo2ZP/cW6SJJoLu1GAPagOYo70ZESFkITKdUW3lK/6RRum39D1iiWy4eIrPnO51DoBPpO aqDCGZaX9bOw4dcGoJqnQsiFMpG2/3DWgUeH2pVBkWremsGW7fMQWufHK9TDRPeNAaVsTi6jCDHaD lRFgZEb82gHWxJerdCJbGObst4ckit7jnN7D6q7CcDsCIijqF5Z5G04Bg6wNYlS/oMHtOTTWo02vd cNnb9HFF++OfgNNLOf/NAWZP3rqpeJ2dLYPfrxAfU5m6AicIpXzwv8aE/zgInml74DQbg+QT1UwxY J6iJDpfiALJK0qAytaIg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rwPiN-00000009BZL-1RZr; Mon, 15 Apr 2024 17:01:55 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rwPi9-00000009BNt-1RC0; Mon, 15 Apr 2024 17:01:47 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 8274560EE1; Mon, 15 Apr 2024 17:01:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D14FBC32783; Mon, 15 Apr 2024 17:01:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713200500; bh=i8/bH2GflHHwL9Q6O831fT+UJyy/N/JxZRrEitYoDU4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JQhmkrbxlkokAIFsbHYvCZlDdyYFqLoERLQD9UjXNswKquLP0xtcV1u+YOoMVBYzN Sb7LZUsXfhw2SSDicmJPXX6wJEySR7qXgqeF6WRCMsTmaxb6dTEEvdKVJ2QF8xV73M zWVAeo2j5d2mIhRamGxbmxaN76CTvh0ZT5e287zxh62+7uCraDbeX1crXvejWzPawj XA+nSfS1WF1QUSKZ+OwNWlmE2LS69a8cbAEH8Ow0G8h8jNNt9mOeOurVvGxQejJFIq lJWV1cL3Cak0wByUAJkuz9CCwdQLw1/FNbKBb/4i5MFAWn2PKkhEyDcE8g7rJ9Kbjc EpnrFltAXi4ng== Date: Mon, 15 Apr 2024 20:00:26 +0300 From: Mike Rapoport To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Andrew Morton , Andy Lutomirski , Arnd Bergmann , Catalin Marinas , Christoph Hellwig , Helge Deller , Lorenzo Stoakes , Luis Chamberlain , Mark Rutland , Masami Hiramatsu , Mathieu Desnoyers , Michael Ellerman , Palmer Dabbelt , Russell King , Song Liu , Steven Rostedt , Thomas Gleixner , Uladzislau Rezki , Will Deacon , bpf@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-trace-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org Subject: Re: [RFC PATCH 6/7] execmem: add support for cache of large ROX pages Message-ID: References: <20240411160526.2093408-1-rppt@kernel.org> <20240411160526.2093408-7-rppt@kernel.org> <20240415104750.GJ40213@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240415104750.GJ40213@noisy.programming.kicks-ass.net> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240415_100141_693525_6595069C X-CRM114-Status: GOOD ( 15.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Apr 15, 2024 at 12:47:50PM +0200, Peter Zijlstra wrote: > On Thu, Apr 11, 2024 at 07:05:25PM +0300, Mike Rapoport wrote: > > > To populate the cache, a writable large page is allocated from vmalloc with > > VM_ALLOW_HUGE_VMAP, filled with invalid instructions and then remapped as > > ROX. > > > +static void execmem_invalidate(void *ptr, size_t size, bool writable) > > +{ > > + if (execmem_info->invalidate) > > + execmem_info->invalidate(ptr, size, writable); > > + else > > + memset(ptr, 0, size); > > +} > > +static void execmem_invalidate(void *ptr, size_t size, bool writeable) > +{ > + /* fill memory with INT3 instructions */ > + if (writeable) > + memset(ptr, 0xcc, size); > + else > + text_poke_set(ptr, 0xcc, size); > +} > > Thing is, 0xcc (aka INT3_INSN_OPCODE) is not an invalid instruction. > It raises #BP not #UD. Do you mean that _invalidate is a poor name choice or that it's necessary to use an instruction that raises #UD? -- Sincerely yours, Mike. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel