Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

4 files changed, 102 insertions, 106 deletions

diff --git a/Documentation/ABI/testing/sysfs-block-rssd b/Documentation/ABI/testing/sysfs-block-rssd
index 679ce3543122..beef30c046b0 100644
--- a/Documentation/ABI/testing/sysfs-block-rssd
+++ b/Documentation/ABI/testing/sysfs-block-rssd
@@ -1,26 +1,5 @@
-What:           /sys/block/rssd*/registers
-Date:           March 2012
-KernelVersion:  3.3
-Contact:        Asai Thambi S P <asamymuthupa@micron.com>
-Description:    This is a read-only file. Dumps below driver information and
-                hardware registers.
-                    - S ACTive
-                    - Command Issue
-                    - Completed
-                    - PORT IRQ STAT
-                    - HOST IRQ STAT
-                    - Allocated
-                    - Commands in Q
-
 What:           /sys/block/rssd*/status
 Date:           April 2012
 KernelVersion:  3.4
 Contact:        Asai Thambi S P <asamymuthupa@micron.com>
 Description:    This is a read-only file. Indicates the status of the device.
-
-What:           /sys/block/rssd*/flags
-Date:           May 2012
-KernelVersion:  3.5
-Contact:        Asai Thambi S P <asamymuthupa@micron.com>
-Description:    This is a read-only file. Dumps the flags in port and driver
-                data structure
diff --git a/Documentation/device-mapper/verity.txt b/Documentation/device-mapper/verity.txt
index 32e48797a14f..9884681535ee 100644
--- a/Documentation/device-mapper/verity.txt
+++ b/Documentation/device-mapper/verity.txt
@@ -7,39 +7,39 @@ This target is read-only.
 
 Construction Parameters
 =======================
-    <version> <dev> <hash_dev> <hash_start>
+    <version> <dev> <hash_dev>
     <data_block_size> <hash_block_size>
     <num_data_blocks> <hash_start_block>
     <algorithm> <digest> <salt>
 
 <version>
-    This is the version number of the on-disk format.
+    This is the type of the on-disk hash format.
 
     0 is the original format used in the Chromium OS.
-	The salt is appended when hashing, digests are stored continuously and
-	the rest of the block is padded with zeros.
+      The salt is appended when hashing, digests are stored continuously and
+      the rest of the block is padded with zeros.
 
     1 is the current format that should be used for new devices.
-	The salt is prepended when hashing and each digest is
-	padded with zeros to the power of two.
+      The salt is prepended when hashing and each digest is
+      padded with zeros to the power of two.
 
 <dev>
-    This is the device containing the data the integrity of which needs to be
+    This is the device containing data, the integrity of which needs to be
     checked.  It may be specified as a path, like /dev/sdaX, or a device number,
     <major>:<minor>.
 
 <hash_dev>
-    This is the device that that supplies the hash tree data.  It may be
+    This is the device that supplies the hash tree data.  It may be
     specified similarly to the device path and may be the same device.  If the
-    same device is used, the hash_start should be outside of the dm-verity
-    configured device size.
+    same device is used, the hash_start should be outside the configured
+    dm-verity device.
 
 <data_block_size>
-    The block size on a data device.  Each block corresponds to one digest on
-    the hash device.
+    The block size on a data device in bytes.
+    Each block corresponds to one digest on the hash device.
 
 <hash_block_size>
-    The size of a hash block.
+    The size of a hash block in bytes.
 
 <num_data_blocks>
     The number of data blocks on the data device.  Additional blocks are
@@ -65,7 +65,7 @@ Construction Parameters
 Theory of operation
 ===================
 
-dm-verity is meant to be setup as part of a verified boot path.  This
+dm-verity is meant to be set up as part of a verified boot path.  This
 may be anything ranging from a boot using tboot or trustedgrub to just
 booting from a known-good device (like a USB drive or CD).
 
@@ -73,20 +73,20 @@ When a dm-verity device is configured, it is expected that the caller
 has been authenticated in some way (cryptographic signatures, etc).
 After instantiation, all hashes will be verified on-demand during
 disk access.  If they cannot be verified up to the root node of the
-tree, the root hash, then the I/O will fail.  This should identify
+tree, the root hash, then the I/O will fail.  This should detect
 tampering with any data on the device and the hash data.
 
 Cryptographic hashes are used to assert the integrity of the device on a
-per-block basis.  This allows for a lightweight hash computation on first read
-into the page cache.  Block hashes are stored linearly-aligned to the nearest
-block the size of a page.
+per-block basis. This allows for a lightweight hash computation on first read
+into the page cache. Block hashes are stored linearly, aligned to the nearest
+block size.
 
 Hash Tree
 ---------
 
 Each node in the tree is a cryptographic hash.  If it is a leaf node, the hash
-is of some block data on disk.  If it is an intermediary node, then the hash is
-of a number of child nodes.
+of some data block on disk is calculated. If it is an intermediary node,
+the hash of a number of child nodes is calculated.
 
 Each entry in the tree is a collection of neighboring nodes that fit in one
 block.  The number is determined based on block_size and the size of the
@@ -110,63 +110,23 @@ alg = sha256, num_blocks = 32768, block_size = 4096
 On-disk format
 ==============
 
-Below is the recommended on-disk format. The verity kernel code does not
-read the on-disk header. It only reads the hash blocks which directly
-follow the header. It is expected that a user-space tool will verify the
-integrity of the verity_header and then call dmsetup with the correct
-parameters. Alternatively, the header can be omitted and the dmsetup
-parameters can be passed via the kernel command-line in a rooted chain
-of trust where the command-line is verified.
+The verity kernel code does not read the verity metadata on-disk header.
+It only reads the hash blocks which directly follow the header.
+It is expected that a user-space tool will verify the integrity of the
+verity header.
 
-The on-disk format is especially useful in cases where the hash blocks
-are on a separate partition. The magic number allows easy identification
-of the partition contents. Alternatively, the hash blocks can be stored
-in the same partition as the data to be verified. In such a configuration
-the filesystem on the partition would be sized a little smaller than
-the full-partition, leaving room for the hash blocks.
-
-struct superblock {
-	uint8_t signature[8]
-		"verity\0\0";
-
-	uint8_t version;
-		1 - current format
-
-	uint8_t data_block_bits;
-		log2(data block size)
-
-	uint8_t hash_block_bits;
-		log2(hash block size)
-
-	uint8_t pad1[1];
-		zero padding
-
-	uint16_t salt_size;
-		big-endian salt size
-
-	uint8_t pad2[2];
-		zero padding
-
-	uint32_t data_blocks_hi;
-		big-endian high 32 bits of the 64-bit number of data blocks
-
-	uint32_t data_blocks_lo;
-		big-endian low 32 bits of the 64-bit number of data blocks
-
-	uint8_t algorithm[16];
-		cryptographic algorithm
-
-	uint8_t salt[384];
-		salt (the salt size is specified above)
-
-	uint8_t pad3[88];
-		zero padding to 512-byte boundary
-}
+Alternatively, the header can be omitted and the dmsetup parameters can
+be passed via the kernel command-line in a rooted chain of trust where
+the command-line is verified.
 
 Directly following the header (and with sector number padded to the next hash
 block boundary) are the hash blocks which are stored a depth at a time
 (starting from the root), sorted in order of increasing index.
 
+The full specification of kernel parameters and on-disk metadata format
+is available at the cryptsetup project's wiki page
+  http://code.google.com/p/cryptsetup/wiki/DMVerity
+
 Status
 ======
 V (for Valid) is returned if every check performed so far was valid.
@@ -174,21 +134,22 @@ If any check failed, C (for Corruption) is returned.
 
 Example
 =======
-
-Setup a device:
-  dmsetup create vroot --table \
-    "0 2097152 "\
-    "verity 1 /dev/sda1 /dev/sda2 4096 4096 2097152 1 "\
+Set up a device:
+  # dmsetup create vroot --readonly --table \
+    "0 2097152 verity 1 /dev/sda1 /dev/sda2 4096 4096 262144 1 sha256 "\
     "4392712ba01368efdf14b05c76f9e4df0d53664630b5d48632ed17a137f39076 "\
     "1234000000000000000000000000000000000000000000000000000000000000"
 
 A command line tool veritysetup is available to compute or verify
-the hash tree or activate the kernel driver.  This is available from
-the LVM2 upstream repository and may be supplied as a package called
-device-mapper-verity-tools:
-    git://sources.redhat.com/git/lvm2
-    http://sourceware.org/git/?p=lvm2.git
-    http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/verity?cvsroot=lvm2
-
-veritysetup -a vroot /dev/sda1 /dev/sda2 \
-	4392712ba01368efdf14b05c76f9e4df0d53664630b5d48632ed17a137f39076
+the hash tree or activate the kernel device. This is available from
+the cryptsetup upstream repository http://code.google.com/p/cryptsetup/
+(as a libcryptsetup extension).
+
+Create hash on the device:
+  # veritysetup format /dev/sda1 /dev/sda2
+  ...
+  Root hash: 4392712ba01368efdf14b05c76f9e4df0d53664630b5d48632ed17a137f39076
+
+Activate the device:
+  # veritysetup create vroot /dev/sda1 /dev/sda2 \
+    4392712ba01368efdf14b05c76f9e4df0d53664630b5d48632ed17a137f39076
diff --git a/Documentation/prctl/no_new_privs.txt b/Documentation/prctl/no_new_privs.txt
new file mode 100644
index 000000000000..cb705ec69abe
--- /dev/null
+++ b/Documentation/prctl/no_new_privs.txt
@@ -0,0 +1,50 @@
+The execve system call can grant a newly-started program privileges that
+its parent did not have.  The most obvious examples are setuid/setgid
+programs and file capabilities.  To prevent the parent program from
+gaining these privileges as well, the kernel and user code must be
+careful to prevent the parent from doing anything that could subvert the
+child.  For example:
+
+ - The dynamic loader handles LD_* environment variables differently if
+   a program is setuid.
+
+ - chroot is disallowed to unprivileged processes, since it would allow
+   /etc/passwd to be replaced from the point of view of a process that
+   inherited chroot.
+
+ - The exec code has special handling for ptrace.
+
+These are all ad-hoc fixes.  The no_new_privs bit (since Linux 3.5) is a
+new, generic mechanism to make it safe for a process to modify its
+execution environment in a manner that persists across execve.  Any task
+can set no_new_privs.  Once the bit is set, it is inherited across fork,
+clone, and execve and cannot be unset.  With no_new_privs set, execve
+promises not to grant the privilege to do anything that could not have
+been done without the execve call.  For example, the setuid and setgid
+bits will no longer change the uid or gid; file capabilities will not
+add to the permitted set, and LSMs will not relax constraints after
+execve.
+
+Note that no_new_privs does not prevent privilege changes that do not
+involve execve.  An appropriately privileged task can still call
+setuid(2) and receive SCM_RIGHTS datagrams.
+
+There are two main use cases for no_new_privs so far:
+
+ - Filters installed for the seccomp mode 2 sandbox persist across
+   execve and can change the behavior of newly-executed programs.
+   Unprivileged users are therefore only allowed to install such filters
+   if no_new_privs is set.
+
+ - By itself, no_new_privs can be used to reduce the attack surface
+   available to an unprivileged user.  If everything running with a
+   given uid has no_new_privs set, then that uid will be unable to
+   escalate its privileges by directly attacking setuid, setgid, and
+   fcap-using binaries; it will need to compromise something without the
+   no_new_privs bit set first.
+
+In the future, other potentially dangerous kernel features could become
+available to unprivileged tasks if no_new_privs is set.  In principle,
+several options to unshare(2) and clone(2) would be safe when
+no_new_privs is set, and no_new_privs + chroot is considerable less
+dangerous than chroot by itself.
diff --git a/Documentation/stable_kernel_rules.txt b/Documentation/stable_kernel_rules.txt
index f0ab5cf28fca..4a7b54bd37e8 100644
--- a/Documentation/stable_kernel_rules.txt
+++ b/Documentation/stable_kernel_rules.txt
@@ -12,6 +12,12 @@ Rules on what kind of patches are accepted, and which ones are not, into the
    marked CONFIG_BROKEN), an oops, a hang, data corruption, a real
    security issue, or some "oh, that's not good" issue.  In short, something
    critical.
+ - Serious issues as reported by a user of a distribution kernel may also
+   be considered if they fix a notable performance or interactivity issue.
+   As these fixes are not as obvious and have a higher risk of a subtle
+   regression they should only be submitted by a distribution kernel
+   maintainer and include an addendum linking to a bugzilla entry if it
+   exists and additional information on the user-visible impact.
  - New device IDs and quirks are also accepted.
  - No "theoretical race condition" issues, unless an explanation of how the
    race can be exploited is also provided.