sys_write() takes a local copy of f_pos and writes that back
into the struct file. It does this so that two concurrent write()
callers don't make a mess of f_pos, and of the file contents.
ecryptfs should be calling vfs_write(). That way we also get the fsnotify
notifications, which ecryptfs presently appears to have subverted.
Convert direct calls to f_op->write() into calls to vfs_write().
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide an option to provide a view of the encrypted files such that the
metadata is always in the header of the files, regardless of whether the
metadata is actually in the header or in the extended attribute. This mode of
operation is useful for applications like incremental backup utilities that do
not preserve the extended attributes when directly accessing the lower files.
With this option enabled, the files under the eCryptfs mount point will be
read-only.
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Generalize the metadata reading and writing mechanisms, with two targets for
now: metadata in file header and metadata in the user.ecryptfs xattr of the
lower file.
[akpm@osdl.org: printk warning fix]
[bunk@stusta.de: make some needlessly global code static]
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch set introduces the ability to store cryptographic metadata into an
lower file extended attribute rather than the lower file header region.
This patch set implements two new mount options:
ecryptfs_xattr_metadata
- When set, newly created files will have their cryptographic
metadata stored in the extended attribute region of the file rather
than the header.
When storing the data in the file header, there is a minimum of 8KB
reserved for the header information for each file, making each file at
least 12KB in size. This can take up a lot of extra disk space if the user
creates a lot of small files. By storing the data in the extended
attribute, each file will only occupy at least of 4KB of space.
As the eCryptfs metadata set becomes larger with new features such as
multi-key associations, most popular filesystems will not be able to store
all of the information in the xattr region in some cases due to space
constraints. However, the majority of users will only ever associate one
key per file, so most users will be okay with storing their data in the
xattr region.
This option should be used with caution. I want to emphasize that the
xattr must be maintained under all circumstances, or the file will be
rendered permanently unrecoverable. The last thing I want is for a user to
forget to set an xattr flag in a backup utility, only to later discover
that their backups are worthless.
ecryptfs_encrypted_view
- When set, this option causes eCryptfs to present applications a
view of encrypted files as if the cryptographic metadata were
stored in the file header, whether the metadata is actually stored
in the header or in the extended attributes.
No matter what eCryptfs winds up doing in the lower filesystem, I want
to preserve a baseline format compatibility for the encrypted files. As of
right now, the metadata may be in the file header or in an xattr. There is
no reason why the metadata could not be put in a separate file in future
versions.
Without the compatibility mode, backup utilities would have to know to
back up the metadata file along with the files. The semantics of eCryptfs
have always been that the lower files are self-contained units of encrypted
data, and the only additional information required to decrypt any given
eCryptfs file is the key. That is what has always been emphasized about
eCryptfs lower files, and that is what users expect. Providing the
encrypted view option will provide a way to userspace applications wherein
they can always get to the same old familiar eCryptfs encrypted files,
regardless of what eCryptfs winds up doing with the metadata behind the
scenes.
This patch:
Add extended attribute support to version bit vector, flags to indicate when
xattr or encrypted view modes are enabled, and support for the new mount
options.
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Public key support code. This reads and writes packets in the header that
contain public key encrypted file keys. It calls the messaging code in the
previous patch to send and receive encryption and decryption request
packets from the userspace daemon.
[akpm@osdl.org: cleab fix]
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the transport code for public key functionality in eCryptfs. It
manages encryption/decryption request queues with a transport mechanism.
Currently, netlink is the only implemented transport.
Each inode has a unique File Encryption Key (FEK). Under passphrase, a File
Encryption Key Encryption Key (FEKEK) is generated from a salt/passphrase
combo on mount. This FEKEK encrypts each FEK and writes it into the header of
each file using the packet format specified in RFC 2440. This is all
symmetric key encryption, so it can all be done via the kernel crypto API.
These new patches introduce public key encryption of the FEK. There is no
asymmetric key encryption support in the kernel crypto API, so eCryptfs pushes
the FEK encryption and decryption out to a userspace daemon. After
considering our requirements and determining the complexity of using various
transport mechanisms, we settled on netlink for this communication.
eCryptfs stores authentication tokens into the kernel keyring. These tokens
correlate with individual keys. For passphrase mode of operation, the
authentication token contains the symmetric FEKEK. For public key, the
authentication token contains a PKI type and an opaque data blob managed by
individual PKI modules in userspace.
Each user who opens a file under an eCryptfs partition mounted in public key
mode must be running a daemon. That daemon has the user's credentials and has
access to all of the keys to which the user should have access. The daemon,
when started, initializes the pluggable PKI modules available on the system
and registers itself with the eCryptfs kernel module. Userspace utilities
register public key authentication tokens into the user session keyring.
These authentication tokens correlate key signatures with PKI modules and PKI
blobs. The PKI blobs contain PKI-specific information necessary for the PKI
module to carry out asymmetric key encryption and decryption.
When the eCryptfs module parses the header of an existing file and finds a Tag
1 (Public Key) packet (see RFC 2440), it reads in the public key identifier
(signature). The asymmetrically encrypted FEK is in the Tag 1 packet;
eCryptfs puts together a decrypt request packet containing the signature and
the encrypted FEK, then it passes it to the daemon registered for the
current->euid via a netlink unicast to the PID of the daemon, which was
registered at the time the daemon was started by the user.
The daemon actually just makes calls to libecryptfs, which implements request
packet parsing and manages PKI modules. libecryptfs grabs the public key
authentication token for the given signature from the user session keyring.
This auth tok tells libecryptfs which PKI module should receive the request.
libecryptfs then makes a decrypt() call to the PKI module, and it passes along
the PKI block from the auth tok. The PKI uses the blob to figure out how it
should decrypt the data passed to it; it performs the decryption and passes
the decrypted data back to libecryptfs. libecryptfs then puts together a
reply packet with the decrypted FEK and passes that back to the eCryptfs
module.
The eCryptfs module manages these request callouts to userspace code via
message context structs. The module maintains an array of message context
structs and places the elements of the array on two lists: a free and an
allocated list. When eCryptfs wants to make a request, it moves a msg ctx
from the free list to the allocated list, sets its state to pending, and fires
off the message to the user's registered daemon.
When eCryptfs receives a netlink message (via the callback), it correlates the
msg ctx struct in the alloc list with the data in the message itself. The
msg->index contains the offset of the array of msg ctx structs. It verifies
that the registered daemon PID is the same as the PID of the process that sent
the message. It also validates a sequence number between the received packet
and the msg ctx. Then, it copies the contents of the message (the reply
packet) into the msg ctx struct, sets the state in the msg ctx to done, and
wakes up the process that was sleeping while waiting for the reply.
The sleeping process was whatever was performing the sys_open(). This process
originally called ecryptfs_send_message(); it is now in
ecryptfs_wait_for_response(). When it wakes up and sees that the msg ctx
state was set to done, it returns a pointer to the message contents (the reply
packet) and returns. If all went well, this packet contains the decrypted
FEK, which is then copied into the crypt_stat struct, and life continues as
normal.
The case for creation of a new file is very similar, only instead of a decrypt
request, eCryptfs sends out an encrypt request.
> - We have a great clod of key mangement code in-kernel. Why is that
> not suitable (or growable) for public key management?
eCryptfs uses Howells' keyring to store persistent key data and PKI state
information. It defers public key cryptographic transformations to userspace
code. The userspace data manipulation request really is orthogonal to key
management in and of itself. What eCryptfs basically needs is a secure way to
communicate with a particular daemon for a particular task doing a syscall,
based on the UID. Nothing running under another UID should be able to access
that channel of communication.
> - Is it appropriate that new infrastructure for public key
> management be private to a particular fs?
The messaging.c file contains a lot of code that, perhaps, could be extracted
into a separate kernel service. In essence, this would be a sort of
request/reply mechanism that would involve a userspace daemon. I am not aware
of anything that does quite what eCryptfs does, so I was not aware of any
existing tools to do just what we wanted.
> What happens if one of these daemons exits without sending a quit
> message?
There is a stale uid<->pid association in the hash table for that user. When
the user registers a new daemon, eCryptfs cleans up the old association and
generates a new one. See ecryptfs_process_helo().
> - _why_ does it use netlink?
Netlink provides the transport mechanism that would minimize the complexity of
the implementation, given that we can have multiple daemons (one per user). I
explored the possibility of using relayfs, but that would involve having to
introduce control channels and a protocol for creating and tearing down
channels for the daemons. We do not have to worry about any of that with
netlink.
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NFS_SUPER_MAGIC is already defined in include/linux/magic.h
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace existing svc_create_socket() API to allow callers to pass addresses
larger than a sockaddr_in.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for IPv6 addresses in the RPC server's UDP receive path.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Modify svc_tcp_accept to support connecting on IPv6 sockets.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The only reason svcsock.c looks at a sockaddr's port is to check whether the
remote peer is connecting from a privileged port. Refactor this check to hide
processing that is specific to address format.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CMSG_DATA comes in different sizes, depending on address family.
[akpm@linux-foundation.org: remove unneeded do/while (0)]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The rq_daddr field must support larger addresses.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Expand the rq_addr field to allow it to contain larger addresses.
Specifically, we replace a 'sockaddr_in' with a 'sockaddr_storage', then
everywhere the 'sockaddr_in' was referenced, we use instead an accessor
function (svc_addr_in) which safely casts the _storage to _in.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sockaddr_storage will allow us to store arbitrary socket addresses in the
svc_deferred_req struct.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are loads of places where the RPC server assumes that the rq_addr fields
contains an IPv4 address. Top among these are error and debugging messages
that display the server's IP address.
Let's refactor the address printing into a separate function that's smart
enough to figure out the difference between IPv4 and IPv6 addresses.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Clean-up: msg_name and msg_namelen are not used by sock_recvmsg, so don't
bother to set them in svc_recvfrom.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The remote peer's address won't change after the socket has been accepted. We
don't need to call ->getname on every incoming request.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rather than calling svc_sock_enqueue at the end of svc_setup_socket, we now
call it (via svc_sock_recieved) after calling svc_setup_socket at each call
site.
We do this because a subsequent patch will insert some code between the two
calls at one call site.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sometimes we need to create an RPC service but not register it with the local
portmapper. NFSv4 delegation callback, for example.
Change the svc_makesock() API to allow optionally creating temporary or
permanent sockets, optionally registering with the local portmapper, and make
it return the ephemeral port of the new socket.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently in the RPC server, registering with the local portmapper and
creating "permanent" sockets are tied together. Expand the internal APIs to
allow these two socket characteristics to be separately specified.
This will be externalized in the next patch.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use ARRAY_SIZE macro already defined in kernel.h
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I think the following patch should go into the kernel, until the ISDN/CAPI
guys create the real fix for this issue.
The issue is a concurrency issue with some internal CAPI data structure
which can crash the kernel.
On my FritzCard DSL with the AVM driver it crashes about once a day without
this workaround patch. With this workaround patch it's rock-stable (at
least on UP, but I don't see why this shouldn't work on SMP as well. But
maybe I'm missing something.)
This workaround is kind of a sledgehammer which inserts a global lock to
wrap around all the critical sections. Of course, this is a scalability
issue, if you have many ISDN/CAPI cards. But it prevents a crash. So I
vote for this fix to get merged, until people come up with a better
solution. Better have a stable kernel that's less scalable, than a
crashing and useless kernel.
This bug is in the kernel since 2.6.15 (at least).
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Kai Germaschewski <kai.germaschewski@gmx.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename the macro CONFIG_HISAX_HFC4S8S_PCIMEM to simply HISAX_HFC4S8S_PCIMEM so
that it no longer resembles a user-settable kernel config macro.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Based on advice from K. Keil, get rid of remaining traces of defunct test
emulator for HISAX.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Based on advice from K. Keil, rename the special debug option
CONFIG_SERIAL_NOPAUSE_IO to ELSA_SERIAL_NOPAUSE_IO so it no longer resembles a
user-selectable kernel config option.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rename some of the debugging macros for ISDN AVM so that they don't resemble
kernel config settings, as they're primarily for author debugging instead.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace misspelled CONFIG_HISAX_QUADRO with CONFIG_HISAX_SCT_QUADRO.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add proper prototypes in a header file for global code under
drivers/isdn/sc/.
Since the GNU C compiler is now able do tell us that caller and callee
disagreed about the number of arguments of setup_buffers(), this patch
also fixes this bug.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- add functions prototypes for some global functions to header files
- remove unneeded "extern"s from some function prototypes
You might note that this patch results in a new warning - that's due to the
fact that with a proper prototype gcc is able to discover a broken
work_struct conversion.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add correct prototypes in header files for global functions and variables.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a first cut at making the AT91 code use the generic GPIO calls.
Note that the original AT91 GPIO calls merged the "mux pin as GPIO" and "set
GPIO direction" functionality into one API call, contrary to what's specified
as a cross-platform portable model. So this involved a few non-inlinable
functions.
[akpm@osdl.org: cleanups]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This teaches OMAP how to implement the cross-platform GPIO interfaces.
[akpm@osdl.org: cleanups]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This defines a simple and minimalist programming interface for GPIO APIs:
- Documentation/gpio.txt ... describes things (read it)
- include/asm-arm/gpio.h ... defines the ARM hook, which just punts
to <asm/arch/gpio.h> for any implementation
- include/asm-generic/gpio.h ... implement "can sleep" variants as calling
the normal ones, for systems that don't handle i2c expanders.
The immediate need for such a cross-architecture API convention is to support
drivers that work the same on AT91 ARM and AVR32 AP7000 chips, which embed many
of the same controllers but have different CPUs. However, several other users
have been reported, including a driver for a hardware watchdog chip and some
handhelds.org multi-CPU button drivers.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eric Wollesen ported the Bluesmoke Memory Controller driver for the Intel
5000X/V/P (Blackford/Greencreek) chipset to the in kernel EDAC model.
This patch incorporates those required changes to the edac_mc.c and edac_mc.h
core files by added new Fully Buffered DIMM interface to the EDAC Core module.
Signed-off-by: eric wollesen <ericw@xmtp.net>
Signed-off-by: doug thompson <norsk5@xmission.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is an attempt of providing an interface for memory scrubbing control in
EDAC.
This patch modifies the EDAC Core to provide the Interface for memory
controller modules to implment.
The following things are still outstanding:
- K8 is the first implemenation,
The patch provide a method of configuring the K8 hardware memory scrubber
via the 'mcX' sysfs directory. There should be some fallback to a generic
scrubber implemented in software if the hardware does not support
scrubbing.
Or .. the scrubbing sysfs entry should not be visible at all.
- Only works with SDRAM, not cache,
The K8 can scrub cache and l2cache also - but I think this is not so
useful as the cache is busy all the time (one hopes).
One would also expect that cache scrubbing requires hardware support.
- Error Handling,
I would like that errors are returned to the user in "terms of file
system".
- Presentation,
I chose Bandwidth in Bytes/Second as a representation of the scrubbing
rate for the following reasons:
I like that the sysfs entries are sort-of textual, related to something
that makes sense instead of magical values that must be looked up.
"My People" wants "% main memory scrubbed per hour" others prefer "%
memory bandwidth used" as representation, "bandwith used" makes it easy to
calculate both versions in one-liner scripts.
If one later wants to scrub cache, the scaling becomes wierd for K8
changing from "blocks of 64 byte memory" to "blocks of 64 cache lines" to
"blocks of 64 bit". Using "bandwidth used" makes sense in all three cases,
(I.M.O. anyway ;-).
- Discovery,
There is no way to discover the possible settings and what they do
without reading the code and the documentation.
*I* do not know how to make that work in a practical way.
- Bugs(??),
other tools can set invalid values in the memory scrub control register,
those will read back as '-1', requiring the user to reset the scrub rate.
This is how *I* think it should be.
- Afflicting other areas of code,
I made changes to edac_mc.c and edac_mc.h which will show up globally -
this is not nice, it would be better that the memory scrubbing fuctionality
and interface could be entirely contained within the memory controller it
applies to.
Frithiof Jensen
edac_mc.c and its .h file is a CORE helper module for EDAC
driver modules. This provides the abstraction for device specific
drivers. It is fine to modify this CORE to provide help for
new features of the the drivers
doug thompson
Signed-off-by: Frithiof Jensen <frithiof.jensen@ericson.com>
Signed-off-by: doug thompson <norsk5@xmission.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fix/change returns the offset into the page for the ce/ue error, instead
of just 0. The e752x dram controller reads 34:6 of the linear address with
the error.
Signed-off-by: Mike Chan <mikechan@google.com>
Signed-off-by: doug thompson <norsk5@xmission.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The reading of the DRA registers should be a byte at a time (one register at a
time) instead of 4 bytes at a time (four registers). Reading a dword at a
time retrieves erroneous information from all but the first register. A
change was made to read in each register in a loop prior to using the data in
those registers.
Signed-off-by: Brian Pomerantz <bapper@mvista.com>
Signed-off-by: Dave Jiang <djiang@mvista.com>
Signed-off-by: Doug Thompson <norsk5@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Andi Kleen <ak@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The fatal vs. non-fatal mask for the sysbus FERR status is incorrect
according to the E7520 datasheet. This patch corrects the mask to correctly
handle fatal and non-fatal errors.
Signed-off-by: Brian Pomerantz <bapper@mvista.com>
Signed-off-by: Dave Jiang <djiang@mvista.com>
Signed-off-by: Doug Thompson <norsk5@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Andi Kleen <ak@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that I have changed all of the in-tree users remove the old version of
these functions. This should make it clear to any out of tree users that they
should be using kill_pgrp kill_pgrp_info or __kill_pgrp_info instead.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that I have changed all of the users remove the old version of these
functions. This should be a clear hint to any out of tree users that they
should use do_each_pid_task and while_each_pid_task for new code.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There isn't any real advantage to this change except that it allows the old
functions to be removed. Which is easier on maintenance and puts the code in
a more uniform style.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Of kernel subsystems that work with pids the tty layer is probably the largest
consumer. But it has the nice virtue that the assiation with a session only
lasts until the session leader exits. Which means that no reference counting
is required. So using struct pid winds up being a simple optimization to
avoid hash table lookups.
In the long term the use of pid_nr also ensures that when we have multiple pid
spaces mixed everything will work correctly.
Signed-off-by: Eric W. Biederman <eric@maxwell.lnxi.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Every call to is_orphaned_pgrp passed in process_group(current) which is racy
with respect to another thread changing our process group. It didn't bite us
because we were dealing with integers and the worse we would get would be a
stale answer.
In switching the checks to use struct pid to be a little more efficient and
prepare the way for pid namespaces this race became apparent.
So I simplified the calls to the more specialized is_current_pgrp_orphaned so
I didn't have to worry about making logic changes to avoid the race.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michael Halcrow