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From: Roman Gushchin <guro@fb.com>
To: <netdev@vger.kernel.org>
Cc: Tejun Heo <tj@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	<linux-kernel@vger.kernel.org>, <kernel-team@fb.com>,
	Roman Gushchin <guro@fb.com>
Subject: [PATCH v3 net-next 2/5] device_cgroup: prepare code for bpf-based device controller
Date: Sun, 5 Nov 2017 08:15:31 -0500	[thread overview]
Message-ID: <20171105131534.25040-3-guro@fb.com> (raw)
In-Reply-To: <20171105131534.25040-1-guro@fb.com>

This is non-functional change to prepare the device cgroup code
for adding eBPF-based controller for cgroups v2.

The patch performs the following changes:
1) __devcgroup_inode_permission() and devcgroup_inode_mknod()
   are moving to the device-cgroup.h and converting into static inline.
2) __devcgroup_check_permission() is exported.
3) devcgroup_check_permission() wrapper is introduced to be used
   by both existing and new bpf-based implementations.

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
---
 include/linux/device_cgroup.h | 61 ++++++++++++++++++++++++++++++++++++++++---
 security/device_cgroup.c      | 47 ++-------------------------------
 2 files changed, 59 insertions(+), 49 deletions(-)

diff --git a/include/linux/device_cgroup.h b/include/linux/device_cgroup.h
index cdbc344a92e4..2d93d7ecd479 100644
--- a/include/linux/device_cgroup.h
+++ b/include/linux/device_cgroup.h
@@ -1,17 +1,70 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/fs.h>
 
+#define DEVCG_ACC_MKNOD 1
+#define DEVCG_ACC_READ  2
+#define DEVCG_ACC_WRITE 4
+#define DEVCG_ACC_MASK (DEVCG_ACC_MKNOD | DEVCG_ACC_READ | DEVCG_ACC_WRITE)
+
+#define DEVCG_DEV_BLOCK 1
+#define DEVCG_DEV_CHAR  2
+#define DEVCG_DEV_ALL   4  /* this represents all devices */
+
+#ifdef CONFIG_CGROUP_DEVICE
+extern int __devcgroup_check_permission(short type, u32 major, u32 minor,
+					short access);
+#else
+static inline int __devcgroup_check_permission(short type, u32 major, u32 minor,
+					       short access)
+{ return 0; }
+#endif
+
 #ifdef CONFIG_CGROUP_DEVICE
-extern int __devcgroup_inode_permission(struct inode *inode, int mask);
-extern int devcgroup_inode_mknod(int mode, dev_t dev);
+static inline int devcgroup_check_permission(short type, u32 major, u32 minor,
+					     short access)
+{
+	return __devcgroup_check_permission(type, major, minor, access);
+}
+
 static inline int devcgroup_inode_permission(struct inode *inode, int mask)
 {
+	short type, access = 0;
+
 	if (likely(!inode->i_rdev))
 		return 0;
-	if (!S_ISBLK(inode->i_mode) && !S_ISCHR(inode->i_mode))
+
+	if (S_ISBLK(inode->i_mode))
+		type = DEVCG_DEV_BLOCK;
+	else if (S_ISCHR(inode->i_mode))
+		type = DEVCG_DEV_CHAR;
+	else
 		return 0;
-	return __devcgroup_inode_permission(inode, mask);
+
+	if (mask & MAY_WRITE)
+		access |= DEVCG_ACC_WRITE;
+	if (mask & MAY_READ)
+		access |= DEVCG_ACC_READ;
+
+	return devcgroup_check_permission(type, imajor(inode), iminor(inode),
+					  access);
 }
+
+static inline int devcgroup_inode_mknod(int mode, dev_t dev)
+{
+	short type;
+
+	if (!S_ISBLK(mode) && !S_ISCHR(mode))
+		return 0;
+
+	if (S_ISBLK(mode))
+		type = DEVCG_DEV_BLOCK;
+	else
+		type = DEVCG_DEV_CHAR;
+
+	return devcgroup_check_permission(type, MAJOR(dev), MINOR(dev),
+					  DEVCG_ACC_MKNOD);
+}
+
 #else
 static inline int devcgroup_inode_permission(struct inode *inode, int mask)
 { return 0; }
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 968c21557ba7..c65b39bafdfe 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -15,15 +15,6 @@
 #include <linux/rcupdate.h>
 #include <linux/mutex.h>
 
-#define DEVCG_ACC_MKNOD 1
-#define DEVCG_ACC_READ  2
-#define DEVCG_ACC_WRITE 4
-#define DEVCG_ACC_MASK (DEVCG_ACC_MKNOD | DEVCG_ACC_READ | DEVCG_ACC_WRITE)
-
-#define DEVCG_DEV_BLOCK 1
-#define DEVCG_DEV_CHAR  2
-#define DEVCG_DEV_ALL   4  /* this represents all devices */
-
 static DEFINE_MUTEX(devcgroup_mutex);
 
 enum devcg_behavior {
@@ -810,8 +801,8 @@ struct cgroup_subsys devices_cgrp_subsys = {
  *
  * returns 0 on success, -EPERM case the operation is not permitted
  */
-static int __devcgroup_check_permission(short type, u32 major, u32 minor,
-				        short access)
+int __devcgroup_check_permission(short type, u32 major, u32 minor,
+				 short access)
 {
 	struct dev_cgroup *dev_cgroup;
 	bool rc;
@@ -833,37 +824,3 @@ static int __devcgroup_check_permission(short type, u32 major, u32 minor,
 
 	return 0;
 }
-
-int __devcgroup_inode_permission(struct inode *inode, int mask)
-{
-	short type, access = 0;
-
-	if (S_ISBLK(inode->i_mode))
-		type = DEVCG_DEV_BLOCK;
-	if (S_ISCHR(inode->i_mode))
-		type = DEVCG_DEV_CHAR;
-	if (mask & MAY_WRITE)
-		access |= DEVCG_ACC_WRITE;
-	if (mask & MAY_READ)
-		access |= DEVCG_ACC_READ;
-
-	return __devcgroup_check_permission(type, imajor(inode), iminor(inode),
-			access);
-}
-
-int devcgroup_inode_mknod(int mode, dev_t dev)
-{
-	short type;
-
-	if (!S_ISBLK(mode) && !S_ISCHR(mode))
-		return 0;
-
-	if (S_ISBLK(mode))
-		type = DEVCG_DEV_BLOCK;
-	else
-		type = DEVCG_DEV_CHAR;
-
-	return __devcgroup_check_permission(type, MAJOR(dev), MINOR(dev),
-			DEVCG_ACC_MKNOD);
-
-}
-- 
2.13.6

  parent reply	other threads:[~2017-11-05 13:18 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-02 17:15 [PATCH v3 net-next 0/5] eBPF-based device cgroup controller Roman Gushchin
2017-11-02 17:15 ` [PATCH v3 net-next 1/5] device_cgroup: add DEVCG_ prefix to ACC_* and DEV_* constants Roman Gushchin
2017-11-02 17:54   ` Joe Perches
2017-11-02 20:06     ` Roman Gushchin
2017-11-02 17:15 ` [PATCH v3 net-next 2/5] device_cgroup: prepare code for bpf-based device controller Roman Gushchin
2017-11-02 17:15 ` [PATCH v3 net-next 3/5] bpf, cgroup: implement eBPF-based device controller for cgroup v2 Roman Gushchin
2017-11-02 17:15 ` [PATCH v3 net-next 4/5] bpf: move cgroup_helpers from samples/bpf/ to tools/testing/selftesting/bpf/ Roman Gushchin
2017-11-02 17:15 ` [PATCH v3 net-next 5/5] selftests/bpf: add a test for device cgroup controller Roman Gushchin
2017-11-04 13:40 ` [PATCH v3 net-next 0/5] eBPF-based " David Miller
2017-11-05 13:15   ` Roman Gushchin
2017-11-05 13:15     ` [PATCH v3 net-next 1/5] device_cgroup: add DEVCG_ prefix to ACC_* and DEV_* constants Roman Gushchin
2017-11-05 13:15     ` Roman Gushchin [this message]
2017-11-05 13:15     ` [PATCH v3 net-next 3/5] bpf, cgroup: implement eBPF-based device controller for cgroup v2 Roman Gushchin
2017-11-05 13:15     ` [PATCH v3 net-next 4/5] bpf: move cgroup_helpers from samples/bpf/ to tools/testing/selftesting/bpf/ Roman Gushchin
2017-11-05 13:15     ` [PATCH v3 net-next 5/5] selftests/bpf: add a test for device cgroup controller Roman Gushchin
2017-11-05 14:27     ` [PATCH v3 net-next 0/5] eBPF-based " David Miller

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