From patchwork Fri Jun 16 09:06:56 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 13282361 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00924EB64D7 for ; Fri, 16 Jun 2023 09:09:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343975AbjFPJJQ (ORCPT ); Fri, 16 Jun 2023 05:09:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57992 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245052AbjFPJIz (ORCPT ); Fri, 16 Jun 2023 05:08:55 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 499AE423E; Fri, 16 Jun 2023 02:07:13 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id CAC5461844; Fri, 16 Jun 2023 09:07:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 161B3C433C0; Fri, 16 Jun 2023 09:07:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686906432; bh=SssK4C+MROZYzi+b4Qyu0IIYF+H8yC2OIjf9lSsuvAQ=; h=From:To:Cc:Subject:Date:From; b=Fzi//9ZxgLWQfoZfdtXHI64hId/FbDLxPXsJA0sig9i/8y+vTgILgL3B0gbK78OgQ pWOqcI8a3q2uq8HLkgEfQ5zCkQGXAk3VO3Yy3K3/E6WFGUtTB+LZlkl2Gdy8x2q544 0BIm/723DnL+o3tMD/pJX6xIBGKG8qP1xinjGVCtWoaU6ikf9qqLsx9J4aqYECkrE9 d/ay8T+HcYRMl9UHHkPDM9hD8fsPNos8NNmLtD1Xo5YtAY2ed8TDRXod1Aj29JnmR/ mBA0S/t6/zjEWn1Rba8+mxH2EDydli+aEWC9MgbUzd/5QvtF6/mCmbvALM99j5ypBe tnh/wyjYUlFEQ== From: Arnd Bergmann To: James Smart , Dick Kennedy , "James E.J. Bottomley" , "Martin K. Petersen" Cc: Arnd Bergmann , Nathan Chancellor , Nick Desaulniers , Tom Rix , Justin Tee , Kees Cook , "Gustavo A. R. Silva" , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH] scsi: lpfc: fix lpfc_name struct packing Date: Fri, 16 Jun 2023 11:06:56 +0200 Message-Id: <20230616090705.2623408-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Arnd Bergmann clang points out that the lpfc_name structure has an 8-byte alignement requirement on most architectures, but is embedded in a number of other structures that are forced to be only 1-byte aligned: drivers/scsi/lpfc/lpfc_hw.h:1516:30: error: field pe within 'struct lpfc_fdmi_reg_port_list' is less aligned than 'struct lpfc_fdmi_port_entry' and is usually due to 'struct lpfc_fdmi_reg_port_list' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] struct lpfc_fdmi_port_entry pe; drivers/scsi/lpfc/lpfc_hw.h:850:19: error: field portName within 'struct _ADISC' is less aligned than 'struct lpfc_name' and is usually due to 'struct _ADISC' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] drivers/scsi/lpfc/lpfc_hw.h:851:19: error: field nodeName within 'struct _ADISC' is less aligned than 'struct lpfc_name' and is usually due to 'struct _ADISC' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] drivers/scsi/lpfc/lpfc_hw.h:922:19: error: field portName within 'struct _RNID' is less aligned than 'struct lpfc_name' and is usually due to 'struct _RNID' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] drivers/scsi/lpfc/lpfc_hw.h:923:19: error: field nodeName within 'struct _RNID' is less aligned than 'struct lpfc_name' and is usually due to 'struct _RNID' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] From the git history, I can see that all the __packed annotations were done specifically to avoid introducing implicit padding around the lpfc_name instances, though this was probably the wrong approach. To improve this, only annotate the one uint64_t field inside of lpfc_name as packed, with an explicit 4-byte alignment, as is the default already on the 32-bit x86 ABI but not on most others. With this, the other __packed annotations can be removed again, as this avoids the incorrect padding. Two other structures change their layout as a result of this change: - struct _LOGO never gained a __packed annotation even though it has the same alignment problem as the others but is not used anywhere in the driver today. - struct serv_param similarly has this issue, and it is used, my guess is that this is only an internal structure rather than part of a binary interface, so the padding has no negative effect here. Signed-off-by: Arnd Bergmann Reviewed-by: Justin Tee --- drivers/scsi/lpfc/lpfc_hw.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_hw.h b/drivers/scsi/lpfc/lpfc_hw.h index 663755842e4a4..aaea3e31944d0 100644 --- a/drivers/scsi/lpfc/lpfc_hw.h +++ b/drivers/scsi/lpfc/lpfc_hw.h @@ -365,7 +365,7 @@ struct lpfc_name { uint8_t IEEE[6]; /* FC IEEE address */ } s; uint8_t wwn[8]; - uint64_t name; + uint64_t name __packed __aligned(4); } u; }; @@ -850,7 +850,7 @@ typedef struct _ADISC { /* Structure is in Big Endian format */ struct lpfc_name portName; struct lpfc_name nodeName; uint32_t DID; -} __packed ADISC; +} ADISC; typedef struct _FARP { /* Structure is in Big Endian format */ uint32_t Mflags:8; @@ -880,7 +880,7 @@ typedef struct _FAN { /* Structure is in Big Endian format */ uint32_t Fdid; struct lpfc_name FportName; struct lpfc_name FnodeName; -} __packed FAN; +} FAN; typedef struct _SCR { /* Structure is in Big Endian format */ uint8_t resvd1; @@ -924,7 +924,7 @@ typedef struct _RNID { /* Structure is in Big Endian format */ union { RNID_TOP_DISC topologyDisc; /* topology disc (0xdf) */ } un; -} __packed RNID; +} RNID; struct RLS { /* Structure is in Big Endian format */ uint32_t rls; @@ -1514,7 +1514,7 @@ struct lpfc_fdmi_hba_ident { struct lpfc_fdmi_reg_port_list { __be32 EntryCnt; struct lpfc_fdmi_port_entry pe; -} __packed; +}; /* * Register HBA(RHBA)