From nobody Tue Feb 10 10:54:23 2026 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (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 E418B1F4282; Fri, 24 Jan 2025 23:56:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.165.32 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737762993; cv=none; b=j54ak7bEoh/FgEGZERrcIGazWUWHzxfSEgQd5Dfg1AVN7e6VAI419JF8VQcIqM0qkJYhilcQ06qKMXLWq3Sv/spFbZzIHJPjpfX6LfNuX0HgC0quG1RvZYK0SnfHpy6Axc8uo77lbl6v0gwXQvjsoUSUO4APoOHW4uoUffgyO2s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737762993; c=relaxed/simple; bh=bCi69afgKdy8QjDhA126o09f6hVRjp1J+V6hT56xlI8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KdGEDLnPp0c1CU/nz70GI1iauxKIg+sMVzVLpwFTvCe4GG8LlvGDfZzZJoVPULGC/QWnCAnu0MdW3riwQHZeXSDUoMtjN+6AEFWj4iRnPpJHuDwOWlFpKY0oNi2CEt4oYhXGkpCT6oinPz81ze1Ek8525CcJBLzwvT+N+x3eAyY= 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=a2Fn/my0; arc=none smtp.client-ip=205.220.165.32 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="a2Fn/my0" Received: from pps.filterd (m0246627.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 50OIi39S019133; Fri, 24 Jan 2025 23:56:00 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=corp-2023-11-20; bh=fcIGc V/98l8ZSjQDmXrF3affeH5gAuXvROyoFcfZEuw=; b=a2Fn/my0YFitA1HTu3rMs vVjepHWSc4mtb1D4lZwU2+HUiFmyAfRG+b2J9B7sTQIhkhHv+5so55NFpuw+9QB6 5IlnBjtBB1nScTizxp8+HvWpPPlV8Xk7iu5bC2OppEWguINRcXS8x0rTEEduQ8zY 6DphIs0lyq7VA2SY/CjUxmOmQR2yda66f9hy9vTq5C4r9eoCY48aAV/BQhk/YKEf gXDR570rmgzu1e/LVmfqRVSIMF9lquv00jDKnJAiVDdsXsi3N1RZMtOdsZjGiBDt gYZ8Dcz/6PLRmaL0lP7CNShlYBppS11nC8cJec/kCQ23yo/t+0IRNU8t1fN4NuzE w== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 4485qaw408-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 24 Jan 2025 23:56:00 +0000 (GMT) Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 50OMD09b036431; Fri, 24 Jan 2025 23:55:59 GMT Received: from pps.reinject (localhost [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 44917u4ama-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 24 Jan 2025 23:55:59 +0000 Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 50ONsxQE018051; Fri, 24 Jan 2025 23:55:58 GMT Received: from localhost.us.oracle.com (dhcp-10-65-130-174.vpn.oracle.com [10.65.130.174]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTP id 44917u49ww-17; Fri, 24 Jan 2025 23:55:58 +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, jthoughton@google.com, corbet@lwn.net, dave.hansen@intel.com, kirill@shutemov.name, luto@kernel.org, brauner@kernel.org, arnd@arndb.de, ebiederm@xmission.com, catalin.marinas@arm.com, mingo@redhat.com, peterz@infradead.org, liam.howlett@oracle.com, lorenzo.stoakes@oracle.com, vbabka@suse.cz, jannh@google.com, hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, tglx@linutronix.de, cgroups@vger.kernel.org, x86@kernel.org, linux-doc@vger.kernel.org, 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: [PATCH 16/20] mshare: add MSHAREFS_CREATE_MAPPING Date: Fri, 24 Jan 2025 15:54:50 -0800 Message-ID: <20250124235454.84587-17-anthony.yznaga@oracle.com> X-Mailer: git-send-email 2.43.5 In-Reply-To: <20250124235454.84587-1-anthony.yznaga@oracle.com> References: <20250124235454.84587-1-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:18.0.1057,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-01-24_10,2025-01-23_01,2024-11-22_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 phishscore=0 mlxscore=0 spamscore=0 mlxlogscore=999 bulkscore=0 malwarescore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2411120000 definitions=main-2501240162 X-Proofpoint-GUID: 5QNgZKQltQ9yn3rK-ZEnWzGSYsobWy1O X-Proofpoint-ORIG-GUID: 5QNgZKQltQ9yn3rK-ZEnWzGSYsobWy1O Content-Type: text/plain; charset="utf-8" Add an ioctl for mapping objects within an mshare region. The arguments are the same as mmap(). Only shared anonymous memory mapped with MAP_FIXED is supported initially. Signed-off-by: Anthony Yznaga --- include/uapi/linux/msharefs.h | 9 +++++ mm/mshare.c | 65 +++++++++++++++++++++++++++++++++++ 2 files changed, 74 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 9ada1544aeb1..d70f10210b46 100644 --- a/mm/mshare.c +++ b/mm/mshare.c @@ -194,12 +194,60 @@ msharefs_set_size(struct mm_struct *host_mm, struct m= share_data *m_data, return 0; } =20 +static long +msharefs_create_mapping(struct mm_struct *host_mm, struct mshare_data *m_d= ata, + 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; + + /* + * Only anonymous shared memory at fixed addresses is allowed for now. + */ + if ((flags & (MAP_SHARED | MAP_FIXED)) !=3D (MAP_SHARED | MAP_FIXED)) + goto out; + if (fd !=3D -1) + goto out; + + if (mmap_write_lock_killable(host_mm)) { + err =3D -EINTR; + goto out; + } + + err =3D 0; + mapped_addr =3D __do_mmap(NULL, addr, size, prot, flags, vm_flags, + 0, &populate, NULL, host_mm); + + if (IS_ERR_VALUE(mapped_addr)) + err =3D (long)mapped_addr; + + mmap_write_unlock(host_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 *host_mm =3D m_data->mm; struct mshare_info minfo; + struct mshare_create mcreate; =20 switch (cmd) { case MSHAREFS_GET_SIZE: @@ -228,6 +276,23 @@ msharefs_ioctl(struct file *filp, unsigned int cmd, un= signed long arg) =20 return msharefs_set_size(host_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.size =3D=3D 0) { + spin_unlock(&m_data->m_lock); + return -EINVAL; + } + spin_unlock(&m_data->m_lock); + + return msharefs_create_mapping(host_mm, m_data, &mcreate); + default: return -ENOTTY; } --=20 2.43.5