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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 747C0C3DA7F for ; Wed, 31 Jul 2024 22:44:01 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sZI2O-0000vM-HF; Wed, 31 Jul 2024 18:43:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sZI2M-0000tT-5I for qemu-devel@nongnu.org; Wed, 31 Jul 2024 18:43:14 -0400 Received: from mail-pg1-x529.google.com ([2607:f8b0:4864:20::529]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sZI2K-0001se-HK for qemu-devel@nongnu.org; Wed, 31 Jul 2024 18:43:13 -0400 Received: by mail-pg1-x529.google.com with SMTP id 41be03b00d2f7-7a92098ec97so4259859a12.2 for ; Wed, 31 Jul 2024 15:43:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1722465791; x=1723070591; darn=nongnu.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=8D6L6mlJmw04kaqjni1MaM8sLHZt7aAWE1fCvEn+rN8=; b=Eec9nrvp+utPen/ZMeH+7DzwLyk70ByZE69yaUqB8MNq/72gTsw4tC22iaSWIpM/79 2QoWdpWT/4WdWtyWh/RTgDTLpACtfzp4SFqJ7dbqIr+W5EffeIHnIz6gcL0N9KeYYxag mJNO8pUFIvn50+76yUsAI9pt2oJye4RpqW1XyUBO4dQnvbF374WQkZYaOOOjMJNH5mys O+sc0RY2o98MC5BsHzkaqF686AFh5OASYG//AHAvaIzXZouUykf/K6ZrQY/37qOv2N/V lrykZ1iNflliMJZRAkkpK3Yq/OY/JSII7vvbEGU9780eU1qSo9IboF7+o2w5302w2d6q BwaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722465791; x=1723070591; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=8D6L6mlJmw04kaqjni1MaM8sLHZt7aAWE1fCvEn+rN8=; b=eKza0mL1lNffFPXOAfisA2XN89HxvC8hawyDfgn1MsfLedwMrzrO5WhOqKxRQDgk4+ pdnEoPxcAYlFgu6nupyvJJTp1m8JJxuUNmWrTv92NHU2Uzu6PTcyezV/AaHaZFCMrgUh pdrsnqbvJTBAY6OGjXlTzrm490Qcb/ndLQYtcTlyJGtM46SE5OCHnskPdO3tz/SPMkMK /KNrk5A+GkkiSbMWfpCPg+79TC089Z/te6Gt/oA3IH7uv7oU/376vEwe0qNh2+VQQQ/P SrtvO04j1afA7AJzm3VU1eNX8H5TNiJs1Vh5oCBzKlPePYnHVzdOcnRrFFwUSWlYz/jj Vo8g== X-Gm-Message-State: AOJu0YwqW1EbLNLtqdW8WzVXYGsLH4ZP8QWXUdcmr569eJVG2Uy2H5z5 a4QulU5SU5Sv7YB0UVu7nmXn9k44lSToQC8L0UBj5Yb5T0nIXpCA+76bfFpzDc4= X-Google-Smtp-Source: AGHT+IFsFCc3Tawaz8KPT6OOy87cnZDT8hUe96ps0A5t2M466lJE+2H7t546F0h/+DNslq+ZaKfp7A== X-Received: by 2002:a05:6a20:1582:b0:1c0:ef1c:b80 with SMTP id adf61e73a8af0-1c68d15ba68mr1057345637.52.1722465790543; Wed, 31 Jul 2024 15:43:10 -0700 (PDT) Received: from [192.168.1.113] ([203.56.128.103]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-70ead6e18a4sm10460802b3a.9.2024.07.31.15.43.08 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 31 Jul 2024 15:43:09 -0700 (PDT) Message-ID: <7c0af87c-466b-4dba-a132-b14c8d262fd4@linaro.org> Date: Thu, 1 Aug 2024 08:43:04 +1000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] bsd-user/x86_64/target_arch_thread.h: Align stack To: Ilya Leoshkevich , Warner Losh , Kyle Evans Cc: qemu-devel@nongnu.org References: <20240731144428.5882-1-iii@linux.ibm.com> Content-Language: en-US From: Richard Henderson In-Reply-To: <20240731144428.5882-1-iii@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2607:f8b0:4864:20::529; envelope-from=richard.henderson@linaro.org; helo=mail-pg1-x529.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 8/1/24 00:44, Ilya Leoshkevich wrote: > bsd-user qemu-x86_64 almost immediately dies with: > > qemu: 0x4002201a68: unhandled CPU exception 0xd - aborting > > on FreeBSD 14.1-RELEASE. This is an instruction that requires > alignment: > > (gdb) x/i 0x4002201a68 > 0x4002201a68: movaps %xmm0,-0x40(%rbp) > > and the argument is not aligned: > > (gdb) p/x env->regs[5] > $1 = 0x822443b58 > > A quick experiment shows that the userspace entry point expects > misaligned rsp: > > (gdb) starti > (gdb) p/x $rsp > $1 = 0x7fffffffeaa8 > > Emulate this behavior in bsd-user. > > Signed-off-by: Ilya Leoshkevich > --- > bsd-user/x86_64/target_arch_thread.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/bsd-user/x86_64/target_arch_thread.h b/bsd-user/x86_64/target_arch_thread.h > index 52c28906d6d..25233443c14 100644 > --- a/bsd-user/x86_64/target_arch_thread.h > +++ b/bsd-user/x86_64/target_arch_thread.h > @@ -31,7 +31,7 @@ static inline void target_thread_init(struct target_pt_regs *regs, > struct image_info *infop) > { > regs->rax = 0; > - regs->rsp = infop->start_stack; > + regs->rsp = (infop->start_stack & ~0xfUL) - 8; The formula in sys/amd64/amd64/exec_machdep.c, exec_setregs is ((stack - 8) & ~0xful) + 8 With that, Reviewed-by: Richard Henderson r~