From: Eric Sandeen <sandeen@redhat.com>
Date: Tue, 29 Jul 2008 16:50:11 -0500
Subject: [fs] ecryptfs: unaligned access helpers
Message-id: 488F9093.8040801@redhat.com
O-Subject: [RHEL5.3 PATCH 4/5] ecryptfs: unaligned access helpers
Bugzilla: 457143
RH-Acked-by: Jarod Wilson <jwilson@redhat.com>
RH-Acked-by: Jeff Moyer <jmoyer@redhat.com>

Addresses [Bug 457143] RHEL5.3: misc ecryptfs fixes from 2.6.27

Combination of 2 upstream commits (listed below) and ecryptfs'
own unaligned access macros, since the upstream macros don't
exist in the RHEL5 tree.

From: Harvey Harrison <harvey.harrison@gmail.com>
Date: Thu, 24 Jul 2008 04:30:06 +0000 (-0700)
Subject: ecryptfs: crypto.c use unaligned byteorder helpers
X-Git-Tag: v2.6.27-rc1~646
X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=29335c6a41568d4708d4ec3b9187f9b6d302e5ea

ecryptfs: crypto.c use unaligned byteorder helpers

Fixes the following sparse warnings:
fs/ecryptfs/crypto.c:1036:8: warning: cast to restricted __be32
fs/ecryptfs/crypto.c:1038:8: warning: cast to restricted __be32
fs/ecryptfs/crypto.c:1077:10: warning: cast to restricted __be32
fs/ecryptfs/crypto.c:1103:6: warning: incorrect type in assignment (different base types)
fs/ecryptfs/crypto.c:1105:6: warning: incorrect type in assignment (different base types)
fs/ecryptfs/crypto.c:1124:8: warning: incorrect type in assignment (different base types)
fs/ecryptfs/crypto.c:1241:21: warning: incorrect type in assignment (different base types)
fs/ecryptfs/crypto.c:1244:30: warning: incorrect type in assignment (different base types)
fs/ecryptfs/crypto.c:1414:23: warning: cast to restricted __be32
fs/ecryptfs/crypto.c:1417:32: warning: cast to restricted __be16

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index d017cb9..3d1df79 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -33,6 +33,7 @@
 #include <linux/crypto.h>
 #include <linux/file.h>
 #include <linux/scatterlist.h>
+#include <asm/unaligned.h>
 #include "ecryptfs_kernel.h"
 
 static int
@@ -977,10 +978,8 @@ static int contains_ecryptfs_marker(char *data)
 {
 	u32 m_1, m_2;
 
-	memcpy(&m_1, data, 4);
-	m_1 = be32_to_cpu(m_1);
-	memcpy(&m_2, (data + 4), 4);
-	m_2 = be32_to_cpu(m_2);
+	m_1 = get_unaligned_be32(data);
+	m_2 = get_unaligned_be32(data + 4);
 	if ((m_1 ^ MAGIC_ECRYPTFS_MARKER) == m_2)
 		return 1;
 	ecryptfs_printk(KERN_DEBUG, "m_1 = [0x%.8x]; m_2 = [0x%.8x]; "
@@ -1018,8 +1017,7 @@ static int ecryptfs_process_flags(struct ecryptfs_crypt_stat *crypt_stat,
 	int i;
 	u32 flags;
 
-	memcpy(&flags, page_virt, 4);
-	flags = be32_to_cpu(flags);
+	flags = get_unaligned_be32(page_virt);
 	for (i = 0; i < ((sizeof(ecryptfs_flag_map)
 			  / sizeof(struct ecryptfs_flag_map_elem))); i++)
 		if (flags & ecryptfs_flag_map[i].file_flag) {
@@ -1045,11 +1043,9 @@ static void write_ecryptfs_marker(char *page_virt, size_t *written)
 
 	get_random_bytes(&m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2));
 	m_2 = (m_1 ^ MAGIC_ECRYPTFS_MARKER);
-	m_1 = cpu_to_be32(m_1);
-	memcpy(page_virt, &m_1, (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2));
-	m_2 = cpu_to_be32(m_2);
-	memcpy(page_virt + (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2), &m_2,
-	       (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2));
+	put_unaligned_be32(m_1, page_virt);
+	page_virt += (MAGIC_ECRYPTFS_MARKER_SIZE_BYTES / 2);
+	put_unaligned_be32(m_2, page_virt);
 	(*written) = MAGIC_ECRYPTFS_MARKER_SIZE_BYTES;
 }
 
@@ -1066,8 +1062,7 @@ write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat,
 			flags |= ecryptfs_flag_map[i].file_flag;
 	/* Version is in top 8 bits of the 32-bit flag vector */
 	flags |= ((((u8)crypt_stat->file_version) << 24) & 0xFF000000);
-	flags = cpu_to_be32(flags);
-	memcpy(page_virt, &flags, 4);
+	put_unaligned_be32(flags, page_virt);
 	(*written) = 4;
 }
 
@@ -1183,11 +1178,9 @@ ecryptfs_write_header_metadata(char *virt,
 	num_header_extents_at_front =
 		(u16)(crypt_stat->num_header_bytes_at_front
 		      / crypt_stat->extent_size);
-	header_extent_size = cpu_to_be32(header_extent_size);
-	memcpy(virt, &header_extent_size, 4);
+	put_unaligned_be32(header_extent_size, virt);
 	virt += 4;
-	num_header_extents_at_front = cpu_to_be16(num_header_extents_at_front);
-	memcpy(virt, &num_header_extents_at_front, 2);
+	put_unaligned_be16(num_header_extents_at_front, virt);
 	(*written) = 6;
 }
 
@@ -1355,15 +1348,13 @@ static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat,
 	u32 header_extent_size;
 	u16 num_header_extents_at_front;
 
-	memcpy(&header_extent_size, virt, sizeof(u32));
-	header_extent_size = be32_to_cpu(header_extent_size);
-	virt += sizeof(u32);
-	memcpy(&num_header_extents_at_front, virt, sizeof(u16));
-	num_header_extents_at_front = be16_to_cpu(num_header_extents_at_front);
+	header_extent_size = get_unaligned_be32(virt);
+	virt += sizeof(__be32);
+	num_header_extents_at_front = get_unaligned_be16(virt);
 	crypt_stat->num_header_bytes_at_front =
 		(((size_t)num_header_extents_at_front
 		  * (size_t)header_extent_size));
-	(*bytes_read) = (sizeof(u32) + sizeof(u16));
+	(*bytes_read) = (sizeof(__be32) + sizeof(__be16));
 	if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE)
 	    && (crypt_stat->num_header_bytes_at_front
 		< ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) {
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index ac234f4..ba641c0 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -532,6 +532,14 @@ ecryptfs_set_dentry_lower_mnt(struct dentry *dentry, struct vfsmount *lower_mnt)
         __ecryptfs_printk(type "%s: " fmt, __func__, ## arg);
 void __ecryptfs_printk(const char *fmt, ...);
 
+#define get_unaligned_be16(p)		be16_to_cpu(get_unaligned((__be16 *)(p)))
+#define get_unaligned_be32(p)		be32_to_cpu(get_unaligned((__be32 *)(p)))
+#define get_unaligned_be64(p)		be64_to_cpu(get_unaligned((__be64 *)(p)))
+
+#define put_unaligned_be16(p, i)	put_unaligned(cpu_to_be16(p), (__be16 *)(i))
+#define put_unaligned_be32(p, i)	put_unaligned(cpu_to_be32(p), (__be32 *)(i))
+#define put_unaligned_be64(p, i)	put_unaligned(cpu_to_be64(p), (__be64 *)(i))
+
 extern const struct file_operations ecryptfs_main_fops;
 extern const struct file_operations ecryptfs_dir_fops;
 extern struct inode_operations ecryptfs_main_iops;
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index c7215ad..1fb52cd 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -31,6 +31,7 @@
 #include <linux/mount.h>
 #include <linux/crypto.h>
 #include <linux/fs_stack.h>
+#include <asm/unaligned.h>
 #include "ecryptfs_kernel.h"
 
 static struct dentry *lock_parent(struct dentry *dentry)
@@ -364,8 +365,7 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
 		else
 			file_size = i_size_read(lower_dentry->d_inode);
 	} else {
-		memcpy(&file_size, page_virt, sizeof(file_size));
-		file_size = be64_to_cpu(file_size);
+		file_size = get_unaligned_be64(page_virt);
 	}
 	i_size_write(dentry->d_inode, (loff_t)file_size);
 	kmem_cache_free(ecryptfs_header_cache_2, page_virt);
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 5ea7f24..fe6b55e 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -32,6 +32,7 @@
 #include <linux/file.h>
 #include <linux/crypto.h>
 #include <linux/scatterlist.h>
+#include <asm/unaligned.h>
 #include "ecryptfs_kernel.h"
 
 /**
@@ -372,7 +373,6 @@ out:
  */
 static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode)
 {
-	u64 file_size;
 	char *file_size_virt;
 	int rc;
 
@@ -381,9 +381,7 @@ static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode)
 		rc = -ENOMEM;
 		goto out;
 	}
-	file_size = (u64)i_size_read(ecryptfs_inode);
-	file_size = cpu_to_be64(file_size);
-	memcpy(file_size_virt, &file_size, sizeof(u64));
+	put_unaligned_be64(i_size_read(ecryptfs_inode), file_size_virt);
 	rc = ecryptfs_write_lower(ecryptfs_inode, file_size_virt, 0,
 				  sizeof(u64));
 	kfree(file_size_virt);
@@ -403,7 +401,6 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode)
 	struct dentry *lower_dentry =
 		ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry;
 	struct inode *lower_inode = lower_dentry->d_inode;
-	u64 file_size;
 	int rc;
 
 	if (!lower_inode->i_op->getxattr || !lower_inode->i_op->setxattr) {
@@ -424,9 +421,7 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode)
 					   xattr_virt, PAGE_CACHE_SIZE);
 	if (size < 0)
 		size = 8;
-	file_size = (u64)i_size_read(ecryptfs_inode);
-	file_size = cpu_to_be64(file_size);
-	memcpy(xattr_virt, &file_size, sizeof(u64));
+	put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt);
 	rc = lower_inode->i_op->setxattr(lower_dentry, ECRYPTFS_XATTR_NAME,
 					 xattr_virt, size, 0);
 	mutex_unlock(&lower_inode->i_mutex);