From nobody Fri Dec 19 15:28:27 2025 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 89B5E126C07; Tue, 3 Sep 2024 23:24:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.177.32 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725405860; cv=none; b=V8VVwqO87YPeYnSsI9E42b/B4E+I0jxXZFZOF8b4r/2S2of6Voobw1kBEDm12eJWOPmmpAPFgy4sq5RgByaDdPRYH4zjpxuTRofK/y+ANAdbIuceyckcjDptNHRJmR+VmhwiDhmg8xMu/QSAZQLi0ImoYNs/QSWpOKHNaQSfdig= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725405860; c=relaxed/simple; bh=uxUP/pNkMUv55TyRlpx3+NMZ38gYu44VEuKodr0xvtU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PNq5k3d3mbhRs2T8HXXFHsHl0FL1PhffqPAi5RmuEeFYw1gTxonn9Et82QnFWsf8+VdXw3tO5I/8clVsQUFV4d+3LEpwOsB7ds1QFoXVfTGW2PYcBWse7Llxv584Qi7AxOQnZELnmhheRekLaJWo5xJksdNTskcDz6FJgGUGwak= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com; spf=pass smtp.mailfrom=oracle.com; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b=EejzamMD; arc=none smtp.client-ip=205.220.177.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="EejzamMD" Received: from pps.filterd (m0333520.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 483LBTND022739; Tue, 3 Sep 2024 23:23:51 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; s=corp-2023-11-20; bh=V K2/rT5IIEmxprXEAU2yy+HHJnHBBZfWU/+zXLoCJkA=; b=EejzamMDBK7bPK5bb 0qt0mQjn5qkF+bv+ii/+f+UA/hfcsO4FDUSATiJLfN5sAhb7njBr6XKEg26G43N/ Un0lt+S0CoRg1U2RIXQEp2EBtenc6w8MFGkXGalrrGGgX+F6rBhwPpmnzH1Z5DYr V8mNpL9sRagOGCX1auCuiIUgINwjowoouwBVLdEAAKjCXCelimkJHpMK/Z5SQDTQ TyJViwri2XDZLuPG2Fdm15FlIXv2tB/d/mu3VV4Gd2UIeLec5OK9m409R1dId+Nt iN6SRiC/qf/BhY5+gFW4u/jdhJJw6ekLNzFbxSu0DGBJSoD86IlNKtM/wexRBsJl r0XFQ== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 41dk84jug1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 03 Sep 2024 23:23:50 +0000 (GMT) Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 483KsE5R001736; Tue, 3 Sep 2024 23:23:49 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 41bsmfmnn0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 03 Sep 2024 23:23:49 +0000 Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 483NMkfQ040456; Tue, 3 Sep 2024 23:23:48 GMT Received: from localhost.us.oracle.com (dhcp-10-159-133-114.vpn.oracle.com [10.159.133.114]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 41bsmfmmwr-11; Tue, 03 Sep 2024 23:23:48 +0000 From: Anthony Yznaga To: akpm@linux-foundation.org, willy@infradead.org, markhemm@googlemail.com, viro@zeniv.linux.org.uk, david@redhat.com, khalid@kernel.org Cc: anthony.yznaga@oracle.com, andreyknvl@gmail.com, dave.hansen@intel.com, luto@kernel.org, brauner@kernel.org, arnd@arndb.de, ebiederm@xmission.com, catalin.marinas@arm.com, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mhiramat@kernel.org, rostedt@goodmis.org, vasily.averin@linux.dev, xhao@linux.alibaba.com, pcc@google.com, neilb@suse.de, maz@kernel.org Subject: [RFC PATCH v3 10/10] mshare: add MSHAREFS_CREATE_MAPPING Date: Tue, 3 Sep 2024 16:22:41 -0700 Message-ID: <20240903232241.43995-11-anthony.yznaga@oracle.com> X-Mailer: git-send-email 2.43.5 In-Reply-To: <20240903232241.43995-1-anthony.yznaga@oracle.com> References: <20240903232241.43995-1-anthony.yznaga@oracle.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-03_11,2024-09-03_01,2024-09-02_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxscore=0 mlxlogscore=792 suspectscore=0 phishscore=0 bulkscore=0 adultscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2407110000 definitions=main-2409030187 X-Proofpoint-GUID: o4IuCMD6qVU1RpEdvToueyKdV1ZsTS0a X-Proofpoint-ORIG-GUID: o4IuCMD6qVU1RpEdvToueyKdV1ZsTS0a Content-Type: text/plain; charset="utf-8" Add an ioctl for mapping objects within an mshare region. The arguments are the same as mmap() although only shared anonymous memory with some restrictions is supported initially. Signed-off-by: Anthony Yznaga --- include/uapi/linux/msharefs.h | 9 +++++ mm/mshare.c | 71 +++++++++++++++++++++++++++++++++++ 2 files changed, 80 insertions(+) diff --git a/include/uapi/linux/msharefs.h b/include/uapi/linux/msharefs.h index c7b509c7e093..fea0afdf000d 100644 --- a/include/uapi/linux/msharefs.h +++ b/include/uapi/linux/msharefs.h @@ -20,10 +20,19 @@ */ #define MSHAREFS_GET_SIZE _IOR('x', 0, struct mshare_info) #define MSHAREFS_SET_SIZE _IOW('x', 1, struct mshare_info) +#define MSHAREFS_CREATE_MAPPING _IOW('x', 2, struct mshare_create) =20 struct mshare_info { __u64 start; __u64 size; }; =20 +struct mshare_create { + __u64 addr; + __u64 size; + __u64 offset; + __u32 prot; + __u32 flags; + __u32 fd; +}; #endif diff --git a/mm/mshare.c b/mm/mshare.c index 8f47c8d6e6a4..7b89bf7f5ffc 100644 --- a/mm/mshare.c +++ b/mm/mshare.c @@ -16,6 +16,7 @@ =20 #include #include +#include #include #include #include @@ -154,12 +155,65 @@ msharefs_set_size(struct mm_struct *mm, struct mshare= _data *m_data, return 0; } =20 +static long +msharefs_create_mapping(struct mm_struct *mm, struct mshare_data *m_data, + struct mshare_create *mcreate) +{ + unsigned long mshare_start, mshare_end; + unsigned long mapped_addr; + unsigned long populate =3D 0; + unsigned long addr =3D mcreate->addr; + unsigned long size =3D mcreate->size; + unsigned int fd =3D mcreate->fd; + int prot =3D mcreate->prot; + int flags =3D mcreate->flags; + vm_flags_t vm_flags; + int err =3D -EINVAL; + + mshare_start =3D m_data->minfo.start; + mshare_end =3D mshare_start + m_data->minfo.size; + + if ((addr < mshare_start) || (addr >=3D mshare_end) || + (addr + size > mshare_end)) + goto out; + + /* + * XXX Keep things simple initially and only allow the mapping of + * anonymous shared memory at fixed addresses without unmapping. + */ + if ((flags & (MAP_SHARED | MAP_FIXED)) !=3D (MAP_SHARED | MAP_FIXED)) + goto out; + + if (fd !=3D -1) + goto out; + + flags |=3D MAP_FIXED_NOREPLACE; + vm_flags =3D VM_NOHUGEPAGE; + + if (mmap_write_lock_killable(mm)) { + err =3D -EINTR; + goto out; + } + + err =3D 0; + mapped_addr =3D __do_mmap(NULL, addr, size, prot, flags, vm_flags, + 0, &populate, NULL, mm); + + if (IS_ERR_VALUE(mapped_addr)) + err =3D (long)mapped_addr; + + mmap_write_unlock(mm); +out: + return err; +} + static long msharefs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct mshare_data *m_data =3D filp->private_data; struct mm_struct *mm =3D m_data->mm; struct mshare_info minfo; + struct mshare_create mcreate; =20 switch (cmd) { case MSHAREFS_GET_SIZE: @@ -188,6 +242,23 @@ msharefs_ioctl(struct file *filp, unsigned int cmd, un= signed long arg) =20 return msharefs_set_size(mm, m_data, &minfo); =20 + case MSHAREFS_CREATE_MAPPING: + if (copy_from_user(&mcreate, (struct mshare_create __user *)arg, + sizeof(mcreate))) + return -EFAULT; + + /* + * validate mshare region + */ + spin_lock(&m_data->m_lock); + if (m_data->minfo.start =3D=3D 0) { + spin_unlock(&m_data->m_lock); + return -EINVAL; + } + spin_unlock(&m_data->m_lock); + + return msharefs_create_mapping(mm, m_data, &mcreate); + default: return -ENOTTY; } --=20 2.43.5