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 B3C94CD4851 for ; Thu, 14 May 2026 09:31:35 +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=283VyeDOYN6khzf+AS7zjUfNyo5I57uL41Xqvi4jTEM=; b=3ZhcuffXbqQfFBAOcXFfEBBlbD eG+wvbHsjgxQ6Q7v0gtu3r2dqRqsDLuMKFxgfGMHPJ4s4PO1hhgBr2b0EjLj8SpfdEjue7DTcpaVP OgdGQDHWL1OrgU9Fxb4/e6YgcFN6phBCKODZl2F+XhlpUVJiZjxscl2ojPA542tO/QKZWMgGnStVY MXyDM3MlUQ20puJtxQUTnFUSf3EdMRxEkKaE3a3hVc4FhzgMB1u58em1avNpEVh4ALvb/SPTl+gRi mzXbyGYhV/oL+jSWG0yARWRPoV89+dY0GnON2CAzq2eZwsq0PDuGH4SDYALKlmOofvfHjgcdenh+e JW9tu0Wg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wNSPg-000000054Y9-3Izk; Thu, 14 May 2026 09:31:28 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wNSPf-000000054Xb-09JH for linux-arm-kernel@lists.infradead.org; Thu, 14 May 2026 09:31:28 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 5A91844151; Thu, 14 May 2026 09:31:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 59CC8C2BCB3; Thu, 14 May 2026 09:31:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778751086; bh=Szhi4DCrVMTbowBda72sF3jcnYffCJVUI6kqx9OCt1c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Aj3J/mC3MBuxwesfKfl/BkZQvEqu+k+Bsu6C+HEOTcZNSnxk391cxb9lFWCjPMZrV Z4VZjipmw65C/6E3zUZuUSXA3OfYicv+YROnQOqMp0QGteYeZFmbhNcqcV3mVXpwRg N8zj8PGeFegC18eLapnUYsICSKwGubJn2nVpeV/ULp/ZQUbu4ZPYCzJ0guTsNfHEiv BQ//00RZyQT2n/YaTn0PoloinP/FIRXGSELbqDBoImyJBrEIL2LBJ2okD1fTskUbmG 55L8c3FO51RqxtEbbXrP2TCJ+UTdJa/IpZC0/rG/gzi8q9q4OPMTOmEBONNVbmu2oM 8r7qG5QsMAMuQ== Date: Thu, 14 May 2026 10:31:23 +0100 From: Sudeep Holla To: Jamie Nguyen Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Sudeep Holla Subject: Re: [PATCH] firmware: arm_ffa: honor descriptor size in PARTITION_INFO_GET_REGS Message-ID: <20260514-generous-undetectable-mastiff-cc43d3@sudeepholla> References: <20260513032800.68807-1-jamien@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260513032800.68807-1-jamien@nvidia.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260514_023127_110665_901D8640 X-CRM114-Status: GOOD ( 22.00 ) 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 Tue, May 12, 2026 at 08:28:00PM -0700, Jamie Nguyen wrote: > __ffa_partition_info_get_regs() walks the response with a hardcoded > 24-byte stride (regs += 3) even though the SPMC tells us the actual > per-descriptor size via PARTITION_INFO_SZ in x2[63:48]. The size is > read into buf_sz and then thrown away. > > That works while every SPMC returns the FF-A v1.1 layout, but it falls > apart against a v1.3 SPMC returning the 48-byte descriptor. The loop > strides over half a descriptor at a time and ends up parsing every > other entry from a slice of two adjacent ones. > > The FF-A spec (v1.2, section 18.5) says that the producer should > report the descriptor size, and the consumer is supposed to stride by > that size and ignore any trailing fields it doesn't understand. The > non-REGS path (__ffa_partition_info_get) does this already, and the > REGS path should match. > > Use buf_sz for the stride, and bail out with -EPROTO if the SPMC > reports something we can't safely walk. > > Fixes: 7bc0f589c81d ("firmware: arm_ffa: Fix big-endian support in __ffa_partition_info_regs_get()") > Signed-off-by: Jamie Nguyen > --- > drivers/firmware/arm_ffa/driver.c | 35 ++++++++++++++++++++++++++++--- > 1 file changed, 32 insertions(+), 3 deletions(-) > > diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c > index c72ee4756585..b712e8a03dab 100644 > --- a/drivers/firmware/arm_ffa/driver.c > +++ b/drivers/firmware/arm_ffa/driver.c > @@ -321,6 +321,22 @@ __ffa_partition_info_get(u32 uuid0, u32 uuid1, u32 uuid2, u32 uuid3, > #define PART_INFO_ID(x) ((u16)(FIELD_GET(PART_INFO_ID_MASK, (x)))) > #define PART_INFO_EXEC_CXT(x) ((u16)(FIELD_GET(PART_INFO_EXEC_CXT_MASK, (x)))) > #define PART_INFO_PROPERTIES(x) ((u32)(FIELD_GET(PART_INFO_PROPS_MASK, (x)))) > + > +/* > + * FF-A v1.2 section 13.9 Table 13.40: registers x3..x17 carry the partition > + * descriptors, i.e. 15 u64 of payload per FFA_PARTITION_INFO_GET_REGS call. > + */ > +#define FFA_PART_INFO_REGS_PAYLOAD_U64 15 > + > +/* > + * FF-A v1.1 partition information descriptor (FF-A v1.2 section 6.2.1 > + * Table 6.1): id (2) + exec_ctxt (2) + properties (4) + UUID (16) = 24 > + * bytes. This is the minimum size the SPMC must report; the kernel reads > + * exactly these fields and ignores any trailing ones per the forward- > + * compatibility rules in FF-A v1.2 section 18.5. > + */ I can't see any such details is the above mention version and section. Can you confirm you are looking at [1] ? -- Regards, Sudeep [1] https://developer.arm.com/documentation/den0077/j