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 80D1FC531DF for ; Thu, 22 Aug 2024 16:02:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=9xJuhXAlbeMm9rilS6gz9KQUoK10tmN3ZTIXWz7m/mY=; b=LFvgsZDbTOeQOYRxWO3+raO772 S/oNg+MlcgqDP1f7delq59jqA9UXJBmKa283o4uludtJaytvLcWDlOSs+0Nl9ac+1akrC1OuDlynv 9I/Gt9B+++P2dmSxleptcX0jrc0oz2jL99LyzpXyz6+MAlUv8KsCMYR8iRnOSCfT4WgCzQ4x1X1T9 thtDrDnmEUfjyHphfVmPzPB53C6jwyB9Pzxbrf488h4/NUA2e/et39FW6a/Re6NEOl2bYsKOGE6Cz UJvldTydJJ+iwW+5iI9Hbdd+pxCCM7QxP6r5eDUnDeVKVmRzKW968mVmcaLKKbzTzJ5nPS3lWnmo+ 5qTbVhzA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1shAG3-0000000DUYc-0jEK; Thu, 22 Aug 2024 16:01:55 +0000 Received: from nyc.source.kernel.org ([147.75.193.91]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sh9z4-0000000DNzX-43if; Thu, 22 Aug 2024 15:44:24 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 8685FA40531; Thu, 22 Aug 2024 15:44:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDAD5C32782; Thu, 22 Aug 2024 15:44:14 +0000 (UTC) Date: Thu, 22 Aug 2024 16:44:12 +0100 From: Catalin Marinas To: Mark Brown Cc: Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy , Kees Cook , "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Florian Weimer , Christian Brauner , Thiago Jung Bauermann , Ross Burton , Yury Khrustalev , Wilco Dijkstra , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH v11 18/39] arm64/traps: Handle GCS exceptions Message-ID: References: <20240822-arm64-gcs-v11-0-41b81947ecb5@kernel.org> <20240822-arm64-gcs-v11-18-41b81947ecb5@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240822-arm64-gcs-v11-18-41b81947ecb5@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240822_084423_092389_ECC991B7 X-CRM114-Status: GOOD ( 13.62 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Aug 22, 2024 at 02:15:21AM +0100, Mark Brown wrote: > +static void noinstr el0_gcs(struct pt_regs *regs, unsigned long esr) > +{ > + enter_from_user_mode(regs); > + local_daif_restore(DAIF_PROCCTX); > + do_el0_gcs(regs, esr); > + exit_to_user_mode(regs); > +} > + > static void noinstr el0_inv(struct pt_regs *regs, unsigned long esr) > { > enter_from_user_mode(regs); > @@ -766,6 +786,9 @@ asmlinkage void noinstr el0t_64_sync_handler(struct pt_regs *regs) > case ESR_ELx_EC_MOPS: > el0_mops(regs, esr); > break; > + case ESR_ELx_EC_GCS: > + el0_gcs(regs, esr); > + break; > case ESR_ELx_EC_BREAKPT_LOW: > case ESR_ELx_EC_SOFTSTP_LOW: > case ESR_ELx_EC_WATCHPT_LOW: > diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c > index 9e22683aa921..d410dcc12ed8 100644 > --- a/arch/arm64/kernel/traps.c > +++ b/arch/arm64/kernel/traps.c > @@ -500,6 +500,16 @@ void do_el1_bti(struct pt_regs *regs, unsigned long esr) > die("Oops - BTI", regs, esr); > } > > +void do_el0_gcs(struct pt_regs *regs, unsigned long esr) > +{ > + force_signal_inject(SIGSEGV, SEGV_CPERR, regs->pc, 0); > +} Just double checking: a GCSPOPM (for example, it can be a RET) from a non-GCS page would generate a classic permission fault with ISS2.GCS set rather than a GCS exception. That's my reading from the Arm ARM pseudocode, the text isn't clear to me. -- Catalin