From patchwork Thu Feb 7 14:02:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Samuel Thibault X-Patchwork-Id: 157758 Delivered-To: patch@linaro.org Received: by 2002:ac9:7558:0:0:0:0:0 with SMTP id r24csp669950oct; Thu, 7 Feb 2019 06:06:54 -0800 (PST) X-Google-Smtp-Source: AHgI3IYp4WJc/PrPe1+TXglfDCILmXvrV0vC/0dsHhJbaw6G4ElpHaXhm1sa1/Wk2ZGTtn0TN4YO X-Received: by 2002:a1c:b189:: with SMTP id a131mr7904825wmf.38.1549548414762; Thu, 07 Feb 2019 06:06:54 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1549548414; cv=none; d=google.com; s=arc-20160816; b=bwoecTtw91w4b0cA7jRCVJco4gJcPrsz2anwzCQ8AJdl3+tKY27sB8C2PmCgnZKqoP mRjEXiFxAKcwiB91VjO5BRQQvwKEinYIQ6eg8jG+zWqD01gMNuiT2LD/26bxnoWj0QdG dv2nRpaGRGQV6S25awVbxDorVVXBtyElQCwgRs682acuXOpQnGLQqHBVJKidCanOqbzn i3g5HpwR5mLH7rq3BOrv1N/60zG+q4pVOZpYyqowhpTn4u9clNWahU/raBG3Wi26uEzj cjmwspzkYLPcHXLGLzJ4VYN1X+hqcbH+NHyTWxAK4BgRLhHVvfUaOzIMUmTo58Bl4oa5 0yhg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:cc:list-subscribe:list-help:list-post:list-archive :list-unsubscribe:list-id:precedence:subject :content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:to:from; bh=KcCeF72dxSP15VPU3Umy6P5HvUDSDyyWy9IScFQfC/4=; b=g4ogp2hSu9XRE7sjzyXZ6Zew097UkPaeq8Zy/dkGUgZful2qCBDhJl2pHO8wqfzP+P +OAdhRF6jUd2lqxLaXko9GKVGIu4rWvpOxFFk5/J3nsph6ry0M9LRIlyZaUzYSDZ8Xco 8FN3+/7B/1gFlzgPzW+Us4mE8+EnTujGrpG3/KB2xyI90bKnBXRF9y8q/1k4Iusma4yS l537ouWpTl0+/n/vlBcaxwA8Kp96wlqvQZZMPqWUK28OyclHDZLVP3S4ekxu3CIwrnkq jAPZUqKr1oOfb1/kxlW2uQEx1ccfc48R0dw7AUyKpKACIQi2nyqXe0xifbdqzYp7bOHV WtnQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org" Return-Path: Received: from lists.gnu.org (lists.gnu.org. [209.51.188.17]) by mx.google.com with ESMTPS id j74si14437941wmj.3.2019.02.07.06.06.54 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 07 Feb 2019 06:06:54 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; Authentication-Results: mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org" Received: from localhost ([127.0.0.1]:40607 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1grkKL-0003Gc-IO for patch@linaro.org; Thu, 07 Feb 2019 09:06:53 -0500 Received: from eggs.gnu.org ([209.51.188.92]:57237) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1grkHG-0001we-1X for qemu-devel@nongnu.org; Thu, 07 Feb 2019 09:03:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1grkHD-0000rF-Jd for qemu-devel@nongnu.org; Thu, 07 Feb 2019 09:03:41 -0500 Received: from hera.aquilenet.fr ([2a0c:e300::1]:49540) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1grkGy-0000lp-Gw for qemu-devel@nongnu.org; Thu, 07 Feb 2019 09:03:28 -0500 Received: from localhost (localhost [127.0.0.1]) by hera.aquilenet.fr (Postfix) with ESMTP id 25873C8A7; Thu, 7 Feb 2019 15:03:22 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at aquilenet.fr Received: from hera.aquilenet.fr ([127.0.0.1]) by localhost (hera.aquilenet.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xejfqT4Jvwgx; Thu, 7 Feb 2019 15:03:18 +0100 (CET) Received: from function (unknown [160.40.205.85]) by hera.aquilenet.fr (Postfix) with ESMTPSA id 62A81CC15; Thu, 7 Feb 2019 15:03:18 +0100 (CET) Received: from samy by function with local (Exim 4.92-RC4) (envelope-from ) id 1grkGq-0004D2-QH; Thu, 07 Feb 2019 15:03:16 +0100 From: Samuel Thibault To: qemu-devel@nongnu.org, peter.maydell@linaro.org Date: Thu, 7 Feb 2019 16:02:46 +0200 Message-Id: <20190207140316.16103-3-samuel.thibault@ens-lyon.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190207140316.16103-1-samuel.thibault@ens-lyon.org> References: <20190207140316.16103-1-samuel.thibault@ens-lyon.org> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2a0c:e300::1 Subject: [Qemu-devel] [PULLv4 02/32] slirp: Avoid marking naturally packed structs as QEMU_PACKED X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jan.kiszka@siemens.com, stefanha@redhat.com, Samuel Thibault Errors-To: qemu-devel-bounces+patch=linaro.org@nongnu.org Sender: "Qemu-devel" From: Peter Maydell Various ipv6 structs in the slirp headers are marked QEMU_PACKED, but they are actually naturally aligned and will have no padding in them. Instead of marking them with the 'packed' attribute, assert at compile time that they are the size we expect. This allows us to take the address of fields within the structs without risking undefined behaviour, and suppresses clang -Waddress-of-packed-member warnings. Signed-off-by: Peter Maydell Reviewed-by: Eric Blake Signed-off-by: Samuel Thibault --- slirp/ip6.h | 12 ++++++++++-- slirp/ip6_icmp.h | 20 +++++++++++++++----- 2 files changed, 25 insertions(+), 7 deletions(-) -- 2.20.1 diff --git a/slirp/ip6.h b/slirp/ip6.h index 14e9c78735..1e3e329ce6 100644 --- a/slirp/ip6.h +++ b/slirp/ip6.h @@ -133,7 +133,7 @@ struct ip6 { uint8_t ip_nh; /* next header */ uint8_t ip_hl; /* hop limit */ struct in6_addr ip_src, ip_dst; /* source and dest address */ -} QEMU_PACKED; +}; /* * IPv6 pseudo-header used by upper-layer protocols @@ -145,7 +145,15 @@ struct ip6_pseudohdr { uint16_t ih_zero_hi; /* zero */ uint8_t ih_zero_lo; /* zero */ uint8_t ih_nh; /* next header */ -} QEMU_PACKED; +}; +/* + * We don't want to mark these ip6 structs as packed as they are naturally + * correctly aligned; instead assert that there is no stray padding. + * If we marked the struct as packed then we would be unable to take + * the address of any of the fields in it. + */ +QEMU_BUILD_BUG_ON(sizeof(struct ip6) != 40); +QEMU_BUILD_BUG_ON(sizeof(struct ip6_pseudohdr) != 40); #endif diff --git a/slirp/ip6_icmp.h b/slirp/ip6_icmp.h index 32b0914055..2ad2b75e67 100644 --- a/slirp/ip6_icmp.h +++ b/slirp/ip6_icmp.h @@ -48,12 +48,16 @@ struct ndp_ra { /* Router Advertisement Message */ uint16_t lifetime; /* Router Lifetime */ uint32_t reach_time; /* Reachable Time */ uint32_t retrans_time; /* Retrans Timer */ -} QEMU_PACKED; +}; + +QEMU_BUILD_BUG_ON(sizeof(struct ndp_ra) != 12); struct ndp_ns { /* Neighbor Solicitation Message */ uint32_t reserved; struct in6_addr target; /* Target Address */ -} QEMU_PACKED; +}; + +QEMU_BUILD_BUG_ON(sizeof(struct ndp_ns) != 20); struct ndp_na { /* Neighbor Advertisement Message */ #if G_BYTE_ORDER == G_BIG_ENDIAN @@ -72,13 +76,17 @@ struct ndp_na { /* Neighbor Advertisement Message */ reserved_lo:24; #endif struct in6_addr target; /* Target Address */ -} QEMU_PACKED; +}; + +QEMU_BUILD_BUG_ON(sizeof(struct ndp_na) != 20); struct ndp_redirect { uint32_t reserved; struct in6_addr target; /* Target Address */ struct in6_addr dest; /* Destination Address */ -} QEMU_PACKED; +}; + +QEMU_BUILD_BUG_ON(sizeof(struct ndp_redirect) != 36); /* * Structure of an icmpv6 header. @@ -103,7 +111,9 @@ struct icmp6 { #define icmp6_nns icmp6_body.ndp_ns #define icmp6_nna icmp6_body.ndp_na #define icmp6_redirect icmp6_body.ndp_redirect -} QEMU_PACKED; +}; + +QEMU_BUILD_BUG_ON(sizeof(struct icmp6) != 40); #define ICMP6_MINLEN 4 #define ICMP6_ERROR_MINLEN 8 From patchwork Thu Feb 7 14:02:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Samuel Thibault X-Patchwork-Id: 157759 Delivered-To: patch@linaro.org Received: by 2002:ac9:7558:0:0:0:0:0 with SMTP id r24csp670281oct; Thu, 7 Feb 2019 06:07:10 -0800 (PST) X-Google-Smtp-Source: AHgI3IaWqAywWLwp+NZDJeG9sDcEpJcgjdgR0mAfmFQ8udbMxHmbt1VVdQapRg2FmF9M2Ez4Dkr3 X-Received: by 2002:adf:8b83:: with SMTP id o3mr12878261wra.81.1549548429964; Thu, 07 Feb 2019 06:07:09 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1549548429; cv=none; d=google.com; s=arc-20160816; b=GTRsGJbUjnfefDtaoLNfD4OBLwlovB+iqn4+8BFJ2dhbEjGdezK+QaXYpI+Puhotb/ gqPEP4Dsx6N+LD4Dtz6u1Q5a3XarW2mPviD4VSz04Mb/MRNlvKf0AR7bosV4z8g/3ZNU spCrxfBnC3yfmZh+3pouUvHBKG2morlgLUvARcW4hULIcw8f0PCPd/9aaeQGZScdmbWh p05e0ls0N2momcQBy1xWJfoYi6SKmBTMK4vGJ9ZgtuqUY9OyCvRq6J+qX1DgHX6qyXZI S9OjczA3fYDIgE4Z8ERY67um28E5YQH65mcxOfK7jGhF2LnbrqB6dTd5S7Urk5rz8X2m TJPg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:cc:list-subscribe:list-help:list-post:list-archive :list-unsubscribe:list-id:precedence:subject :content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:to:from; bh=c37Oo6eLvoOcn14oMVc6NjO4Og2IlcGPMnzcEwlvs00=; b=L2+rd/l7S9XVG19cVZ+EFQPs84d63OuDlN2y5CzEZeRFIMXz6aQI9je3gRBFGslZ71 0fJ8YjtmAxpF3B7nYlWysJpcLyJvUvUTo8Cmn6TRL2YDe5vIACQGN64e0+4C1GJzpmtq NT6Npe0jPlbPcSL8MpD/BuHK3meV2LhNFB9KxvGy7q+stn1Ruyc4xrNkRYlELUXVOzRK OAaRFRWuCmQdhh5YFAYCkWwKQHV4rgzNiHL+1rK8jI68JaMYMGO2uN1hgPF0d0iBi4ug hCL2GteU2QB+ntHtC4hUQiIoJJ6HUVbpcGmKWxRn5YNUOCQtaduHic9Bzb49nLIKFkGw Q1Hw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org" Return-Path: Received: from lists.gnu.org (lists.gnu.org. [209.51.188.17]) by mx.google.com with ESMTPS id v15si1035344wmc.165.2019.02.07.06.07.09 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 07 Feb 2019 06:07:09 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; Authentication-Results: mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org" Received: from localhost ([127.0.0.1]:40621 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1grkKa-0003Si-Sx for patch@linaro.org; Thu, 07 Feb 2019 09:07:08 -0500 Received: from eggs.gnu.org ([209.51.188.92]:57258) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1grkHJ-0001wr-V9 for qemu-devel@nongnu.org; Thu, 07 Feb 2019 09:03:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1grkHC-0000qa-7h for qemu-devel@nongnu.org; Thu, 07 Feb 2019 09:03:43 -0500 Received: from hera.aquilenet.fr ([185.233.100.1]:41586) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1grkGy-0000m0-Es for qemu-devel@nongnu.org; Thu, 07 Feb 2019 09:03:27 -0500 Received: from localhost (localhost [127.0.0.1]) by hera.aquilenet.fr (Postfix) with ESMTP id 825E9CC15; Thu, 7 Feb 2019 15:03:22 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at aquilenet.fr Received: from hera.aquilenet.fr ([127.0.0.1]) by localhost (hera.aquilenet.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 8tCbRXnn4VTf; Thu, 7 Feb 2019 15:03:19 +0100 (CET) Received: from function (unknown [160.40.205.85]) by hera.aquilenet.fr (Postfix) with ESMTPSA id 8AED0CD1C; Thu, 7 Feb 2019 15:03:18 +0100 (CET) Received: from samy by function with local (Exim 4.92-RC4) (envelope-from ) id 1grkGq-0004D4-Ro; Thu, 07 Feb 2019 15:03:16 +0100 From: Samuel Thibault To: qemu-devel@nongnu.org, peter.maydell@linaro.org Date: Thu, 7 Feb 2019 16:02:47 +0200 Message-Id: <20190207140316.16103-4-samuel.thibault@ens-lyon.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190207140316.16103-1-samuel.thibault@ens-lyon.org> References: <20190207140316.16103-1-samuel.thibault@ens-lyon.org> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 185.233.100.1 Subject: [Qemu-devel] [PULLv4 03/32] slirp: Don't mark struct ipq or struct ipasfrag as packed X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jan.kiszka@siemens.com, stefanha@redhat.com, Samuel Thibault Errors-To: qemu-devel-bounces+patch=linaro.org@nongnu.org Sender: "Qemu-devel" From: Peter Maydell There is no reason to mark the struct ipq and struct ipasfrag as packed: they are naturally aligned anyway, and are not representing any on-the-wire packet format. Indeed they vary in size depending on the size of pointers on the host system, because the 'struct qlink' members include 'void *' fields. Dropping the 'packed' annotation fixes clang -Waddress-of-packed-member warnings and probably lets the compiler generate better code too. The only thing we do care about in the layout of the struct is that the frag_link matches up with the ipf_link of the struct ipasfrag, as documented in the comment on that struct; assert at build time that this is the case. Signed-off-by: Peter Maydell Reviewed-by: Eric Blake Signed-off-by: Samuel Thibault --- slirp/ip.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) -- 2.20.1 diff --git a/slirp/ip.h b/slirp/ip.h index 243b6c8b24..20614f3b53 100644 --- a/slirp/ip.h +++ b/slirp/ip.h @@ -217,7 +217,7 @@ struct ipq { uint8_t ipq_p; /* protocol of this fragment */ uint16_t ipq_id; /* sequence id for reassembly */ struct in_addr ipq_src,ipq_dst; -} QEMU_PACKED; +}; /* * Ip header, when holding a fragment. @@ -227,7 +227,10 @@ struct ipq { struct ipasfrag { struct qlink ipf_link; struct ip ipf_ip; -} QEMU_PACKED; +}; + +QEMU_BUILD_BUG_ON(offsetof(struct ipq, frag_link) != + offsetof(struct ipasfrag, ipf_link)); #define ipf_off ipf_ip.ip_off #define ipf_tos ipf_ip.ip_tos