Commit graph

218426 commits

Author SHA1 Message Date
Joerg Roedel
3f6a9d1693 KVM: SVM: Sync efer back into nested vmcb
This patch fixes a bug in a nested hypervisor that heavily
switches between real-mode and long-mode. The problem is
fixed by syncing back efer into the guest vmcb on emulated
vmexit.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:50:03 +02:00
Xiao Guangrong
19ada5c4b6 KVM: MMU: remove valueless output message
After commit 53383eaad08d, the '*spte' has updated before call
rmap_remove()(in most case it's 'shadow_trap_nonpresent_pte'), so
remove this information from error message

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:50:02 +02:00
Avi Kivity
d359192fea KVM: VMX: Use host_gdt variable wherever we need the host gdt
Now that we have the host gdt conveniently stored in a variable, make use
of it instead of querying the cpu.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:50:01 +02:00
Avi Kivity
e071edd5ba KVM: x86 emulator: unify the two Group 3 variants
Use just one group table for byte (F6) and word (F7) opcodes.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:50:00 +02:00
Avi Kivity
dfe11481d8 KVM: x86 emulator: Allow LOCK prefix for NEG and NOT
Opcodes F6/2, F6/3, F7/2, F7/3.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:59 +02:00
Avi Kivity
4968ec4e26 KVM: x86 emulator: simplify Group 1 decoding
Move operand decoding to the opcode table, keep lock decoding in the group
table.  This allows us to get consolidate the four variants of Group 1 into one
group.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:58 +02:00
Avi Kivity
52811d7de5 KVM: x86 emulator: mix decode bits from opcode and group decode tables
Allow bits that are common to all members of a group to be specified in the
opcode table instead of the group table.  This allows some simplification
of the decode tables.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:58 +02:00
Avi Kivity
047a481809 KVM: x86 emulator: add Undefined decode flag
Add a decode flag to indicate the instruction is invalid.  Will come in useful
later, when we mix decode bits from the opcode and group table.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:57 +02:00
Avi Kivity
2ce495365f KVM: x86 emulator: Make group storage bits separate from operand bits
Currently group bits are stored in bits 0:7, where operand bits are stored.

Make group bits be 0:3, and move the existing bits 0:3 to 16:19, so we can
mix group and operand bits.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:55 +02:00
Avi Kivity
880a188378 KVM: x86 emulator: consolidate Jcc rel32 decoding
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:55 +02:00
Avi Kivity
be8eacddbd KVM: x86 emulator: consolidate CMOVcc decoding
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:53 +02:00
Avi Kivity
b6e6153885 KVM: x86 emulator: consolidate MOV reg, imm decoding
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:52 +02:00
Avi Kivity
b3ab3405fe KVM: x86 emulator: consolidate Jcc rel8 decoding
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:51 +02:00
Avi Kivity
3849186c38 KVM: x86 emulator: consolidate push/pop reg decoding
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:49 +02:00
Avi Kivity
749358a6b4 KVM: x86 emulator: consolidate inc/dec reg decoding
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:48 +02:00
Avi Kivity
83babbca46 KVM: x86 emulator: add macros for repetitive instructions
Some instructions are repetitive in the opcode space, add macros for
consolidating them.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:48 +02:00
Avi Kivity
91269b8f94 KVM: x86 emulator: fix handling for unemulated instructions
If an instruction is present in the decode tables but not in the execution
switch, it will be emulated as a NOP.  An example is IRET (0xcf).

Fix by adding default: labels to the execution switches.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-10-24 10:49:47 +02:00
Jiri Kosina
d8692ac012 HID: fix mismerge in hid-lg
Fix wrong merge in hid-lg -- report fixup functions now get
pointer to rdesc.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-10-23 22:59:33 +02:00
Jiri Kosina
f1275410a1 Merge branch 'waltop' into for-linus 2010-10-23 22:54:53 +02:00
Jack Morgenstein
d0d68b8693 IB/mlx4: Signal node desc changes to SM by using FW to generate trap 144
The Node Description cannot be changed via MADs (it is read-only).
Until now, it was changed in the driver via sysfs, and the new Node
Description was simply inserted by the driver into MAD responses
(replacing the description returned by FW).

System startup scripts use the sysfs interface to change the node
description at driver startup to show the hostname, etc. However, this
has a race condition: the SM could discover the original FW node
description rather than the system-specific description if it queried the
port before the startup scripts finish running.

For mlx4, we fix this with a new FW command (SET_NODE) that allows
passing the new node description to FW.  When this command is invoked,
FW sends a trap 144 to the SM.  When it gets this trap, the SM can
query the node to obtain the new node description -- thus eliminating
the effects of the race.

This patch simply calls SET_NODE command when a new node description
is entered via sysfs (thus causing trap 144 to be issued by the FW).
We ignore all failures of the SET_NODE command (including those caused
by using a device FW that predates the SET_NODE command), since in
that case things work just as before.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-10-23 13:53:09 -07:00
Jiri Kosina
8b66a16f25 Merge branch 'uc-logic' into for-linus
Conflicts:
	drivers/hid/hid-ids.h
	drivers/hid/hid-lg.c
	drivers/hid/usbhid/hid-quirks.c
2010-10-23 22:49:32 +02:00
Jiri Kosina
bbd128b5ac Merge branches '3m', 'egalax', 'logitech', 'magicmouse', 'ntrig' and 'roccat' into for-linus 2010-10-23 22:47:38 +02:00
matt mooney
7454159d3c IB: Replace EXTRA_CFLAGS with ccflags-y
Signed-off-by: matt mooney <mfm@muteddisk.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-10-23 13:45:03 -07:00
Jiri Kosina
c3d9d74336 Merge branches 'upstream' and 'upstream-fixes' into for-linus 2010-10-23 22:44:36 +02:00
Steve Wise
97cb7e40c6 RDMA/ucma: Allow tuning the max listen backlog
For iWARP connections, the connect request is carried in a TCP payload
on an already established TCP connection.  So if the ucma's backlog is
full, the connection request is transmitted and acked at the TCP level
by the time the connect request gets dropped in the ucma.  The end
result is the connection gets rejected by the iWARP provider.
Further, a 32 node 256NP OpenMPI job will generate > 128 connect
requests on some ranks.

This patch increases the default max backlog to 1024, and adds a
sysctl variable so the backlog can be adjusted at run time.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-10-23 13:41:40 -07:00
Eli Cohen
c3aa9b186b IPoIB: Set dev_id field of net_device
Use the net device's dev_id field to encode the port number of the pci
device.  This can be used to to associate a net device with the pci
device's port. The encoding is: dev_id = port - 1.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2010-10-23 13:35:48 -07:00
Trond Myklebust
3201f3dd73 NFSv4: Fix a regression in decode_getfattr
We don't want to have the mounted_on_fileid overwrite the true fileid. We
only return the former if the server didn't supply the true fileid.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:43:10 -04:00
Trond Myklebust
7ad0735300 NFSv4: Fix up decode_attr_filehandle() to handle the case of empty fh pointer
decode_attr_filehandle still needs to skip the XDR-encoded filehandle if
someone passes a null pointer argument.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:34:20 -04:00
Trond Myklebust
4a201d6e3f NFS: Ensure we check all allocation return values in new readdir code
Also some clean ups.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:38 -04:00
Bryan Schumaker
82f2e5472e NFS: Readdir plus in v4
By requsting more attributes during a readdir, we can mimic the readdir plus
operation that was in NFSv3.

To test, I ran the command `ls -lU --color=none` on directories with various
numbers of files.  Without readdir plus, I see this:

n files |    100    |   1,000   |  10,000   |  100,000  | 1,000,000
--------+-----------+-----------+-----------+-----------+----------
real    | 0m00.153s | 0m00.589s | 0m05.601s | 0m56.691s | 9m59.128s
user    | 0m00.007s | 0m00.007s | 0m00.077s | 0m00.703s | 0m06.800s
sys     | 0m00.010s | 0m00.070s | 0m00.633s | 0m06.423s | 1m10.005s
access  | 3         | 1         | 1         | 4         | 31
getattr | 2         | 1         | 1         | 1         | 1
lookup  | 104       | 1,003     | 10,003    | 100,003   | 1,000,003
readdir | 2         | 16        | 158       | 1,575     | 15,749
total   | 111       | 1,021     | 10,163    | 101,583   | 1,015,784

With readdir plus enabled, I see this:

n files |    100    |   1,000   |  10,000   |  100,000  | 1,000,000
--------+-----------+-----------+-----------+-----------+----------
real    | 0m00.115s | 0m00.206s | 0m01.079s | 0m12.521s | 2m07.528s
user    | 0m00.003s | 0m00.003s | 0m00.040s | 0m00.290s | 0m03.296s
sys     | 0m00.007s | 0m00.020s | 0m00.120s | 0m01.357s | 0m17.556s
access  | 3         | 1         | 1         | 1         | 7
getattr | 2         | 1         | 1         | 1         | 1
lookup  | 4         | 3         | 3         | 3         | 3
readdir | 6         | 62        | 630       | 6,300     | 62,993
total   | 15        | 67        | 635       | 6,305     | 63,004

Readdir plus disabled has about a 16x increase in the number of rpc calls and
is 4 - 5 times slower on large directories.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:37 -04:00
Bryan Schumaker
ae42c70a60 NFS: introduce generic decode_getattr function
Getattr should be able to decode errors and the readdir file handle.
decode_getfattr_attrs does the actual attribute decoding, while
decode_getfattr_generic will check the opcode before decoding.  This will
let other functions call decode_getfattr_attrs to decode their attributes.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:37 -04:00
Bryan Schumaker
9942438089 NFS: check xdr_decode for errors
Check if the decoded entry has the eof bit set when returning from xdr_decode
with an error.  If it does, we should set the eof bits in the array before
returning.  This should keep us from looping when we expect more data but the
server doesn't give us anything new.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:36 -04:00
Bryan Schumaker
3c8a1aeed8 NFS: nfs_readdir_filler catch all errors
Check for all errors, not a specific one.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:35 -04:00
Bryan Schumaker
56e4ebf877 NFS: readdir with vmapped pages
We can use vmapped pages to read more information from the network at once.
This will reduce the number of calls needed to complete a readdir.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
[trondmy: Added #include for linux/vmalloc.h> in fs/nfs/dir.c]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:35 -04:00
Bryan Schumaker
afa8ccc978 NFS: remove page size checking code
Remove the page size checking code for a readdir decode.  This is now done
by decode_dirent with xdr_streams.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:34 -04:00
Bryan Schumaker
babddc72a9 NFS: decode_dirent should use an xdr_stream
Convert nfs*xdr.c to use an xdr stream in decode_dirent.  This will prevent a
kernel oops that has been occuring when reading a vmapped page.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:33 -04:00
Trond Myklebust
ba8e452a4f SUNRPC: Add a helper function xdr_inline_peek
We sometimes need to be able to read ahead in an xdr_stream without
incrementing the current pointer position.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:32 -04:00
Bryan Schumaker
0715dc632a NFS: remove readdir plus limit
We will now use readdir plus even on directories that are very large.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:32 -04:00
Bryan Schumaker
d39ab9de3b NFS: re-add readdir plus
This patch adds readdir plus support to the cache array.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:31 -04:00
Trond Myklebust
baf57a09e9 NFS: Optimise the readdir searches
If we're going through the loop in nfs_readdir() more than once, we usually
do not want to restart searching from the beginning of the pages cache.

We only want to do that if the previous search failed...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:30 -04:00
Bryan Schumaker
d1bacf9eb2 NFS: add readdir cache array
This patch adds the readdir cache array and functions to retreive the array
stored on a cache page, clear the array by freeing allocated memory, add an
entry to the array, and search the array for a given cookie.

It then modifies readdir to make use of the new cache array.
With the new cache array method, we no longer need some of this code.

Finally, nfs_llseek_dir() will set file->f_pos to a value greater than 0 and
desc->dir_cookie to zero.  When we see this, readdir needs to find the file
at position file->f_pos from the start of the directory.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:30 -04:00
Randy Dunlap
8c7597f6ce nfs: include ratelimit.h, fix nfs4state build error
nfs4state.c uses interfaces from ratelimit.h.  It needs to include
that header file to fix build errors:

fs/nfs/nfs4state.c:1195: warning: type defaults to 'int' in declaration of 'DEFINE_RATELIMIT_STATE'
fs/nfs/nfs4state.c:1195: warning: parameter names (without types) in function declaration
fs/nfs/nfs4state.c:1195: error: invalid storage class for function 'DEFINE_RATELIMIT_STATE'
fs/nfs/nfs4state.c:1195: error: implicit declaration of function '__ratelimit'
fs/nfs/nfs4state.c:1195: error: '_rs' undeclared (first use in this function)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc:	Trond Myklebust <Trond.Myklebust@netapp.com>
Cc:	linux-nfs@vger.kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:29 -04:00
Trond Myklebust
168667c43b NFSv4: The state manager must ignore EKEYEXPIRED.
Otherwise, we cannot recover state correctly.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:28 -04:00
Trond Myklebust
898f635c42 NFSv4: Don't ignore the error return codes from nfs_intent_set_file
If nfs_intent_set_file() returns an error, we usually want to pass that
back up the stack.

Also ensure that nfs_open_revalidate() returns '1' on success.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-10-23 15:27:17 -04:00
Linus Torvalds
35da7a307c Merge branch 'for-2.6.37/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.37/core' of git://git.kernel.dk/linux-2.6-block:
  block: fix use-after-free bug in blk throttle code
2010-10-23 11:55:00 -07:00
Linus Torvalds
5f05647dd8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1699 commits)
  bnx2/bnx2x: Unsupported Ethtool operations should return -EINVAL.
  vlan: Calling vlan_hwaccel_do_receive() is always valid.
  tproxy: use the interface primary IP address as a default value for --on-ip
  tproxy: added IPv6 support to the socket match
  cxgb3: function namespace cleanup
  tproxy: added IPv6 support to the TPROXY target
  tproxy: added IPv6 socket lookup function to nf_tproxy_core
  be2net: Changes to use only priority codes allowed by f/w
  tproxy: allow non-local binds of IPv6 sockets if IP_TRANSPARENT is enabled
  tproxy: added tproxy sockopt interface in the IPV6 layer
  tproxy: added udp6_lib_lookup function
  tproxy: added const specifiers to udp lookup functions
  tproxy: split off ipv6 defragmentation to a separate module
  l2tp: small cleanup
  nf_nat: restrict ICMP translation for embedded header
  can: mcp251x: fix generation of error frames
  can: mcp251x: fix endless loop in interrupt handler if CANINTF_MERRF is set
  can-raw: add msg_flags to distinguish local traffic
  9p: client code cleanup
  rds: make local functions/variables static
  ...

Fix up conflicts in net/core/dev.c, drivers/net/pcmcia/smc91c92_cs.c and
drivers/net/wireless/ath/ath9k/debug.c as per David
2010-10-23 11:47:02 -07:00
Jens Axboe
7ad58c0286 block: fix use-after-free bug in blk throttle code
blk_throtl_exit() frees the throttle data hanging off the queue
in blk_cleanup_queue(), but blk_put_queue() will indirectly
dereference this data when calling blk_sync_queue() which in
turns calls throtl_shutdown_timer_wq().

Fix this by moving the freeing of the throttle data to when
the queue is truly being released, and post the call to
blk_sync_queue().

Reported-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-23 20:40:26 +02:00
Rafael J. Wysocki
a1b4bd694a ACPI / Battery: Return -ENODEV for unknown values in get_property()
The function acpi_battery_get_property() is called by the
power supply framework's function power_supply_show_property()
implementing the sysfs interface for power supply devices as the
ACPI battery driver's ->get_property() callback.  Thus it is supposed
to return error code if the value of the given property is unknown.
Unfortunately, however, it returns 0 in those cases and puts a
wrong (negative) value into the intval field of the
union power_supply_propval object provided by
power_supply_show_property().  In consequence, wrong negative
values are read by user space from the battery's sysfs files.

Fix this by making acpi_battery_get_property() return -ENODEV
for properties with unknown values (-ENODEV is returned, because
power_supply_uevent() returns with error for any other error code
returned by power_supply_show_property()).

Reported-and-tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-10-23 14:05:03 -04:00
Linus Torvalds
02f36038c5 Merge branches 'softirq-for-linus', 'x86-debug-for-linus', 'x86-numa-for-linus', 'x86-quirks-for-linus', 'x86-setup-for-linus', 'x86-uv-for-linus' and 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'softirq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  softirqs: Make wakeup_softirqd static

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, asm: Restore parentheses around one pushl_cfi argument
  x86, asm: Fix ancient-GAS workaround
  x86, asm: Fix CFI macro invocations to deal with shortcomings in gas

* 'x86-numa-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, numa: Assign CPUs to nodes in round-robin manner on fake NUMA

* 'x86-quirks-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: HPET force enable for CX700 / VIA Epia LT

* 'x86-setup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, setup: Use string copy operation to optimze copy in kernel compression

* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, UV: Use allocated buffer in tlb_uv.c:tunables_read()

* 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, vm86: Fix preemption bug for int1 debug and int3 breakpoint handlers.
2010-10-23 08:25:36 -07:00
Linus Torvalds
6c2754c28f Revert "tty: Add a new file /proc/tty/consoles"
This reverts commit f4a3e0bceb.  Jiri
Sladby points out that the tty structure we're using may already be
gone, and Al Viro doesn't hold back in complaining about the random
loading of 'filp->private_data' which doesn't have to be a pointer at
all, nor does checking the magic field for TTY_MAGIC prove anything.

Belated review by Al:

 "a) global variable depending on stdin of the last opener? Affecting
     output of read(2)? Really?

  b) iterator is broken; list should be locked in ->start(), unlocked in
     ->stop() and *NOT* unlocked/relocked in ->next()

  c) ->show() ought to do nothing in case of ->device == NULL, instead
     of skipping those in ->next()/->start()

  d) regardless of the merits of the bright idea about asterisk at that
     line in output *and* regardless of (a), the implementation is not
     only atrociously ugly, it's actually very likely to be a roothole.
     Verifying that Cthulhu knows what number happens to be address of a
     tty_struct by blindly dereferencing memory at that address...
     Ouch.

  Please revert that crap."

And Christoph pipes in and NAK's the approach of walking fd tables etc
too.  So it's pretty unanimous.

Noticed-by: Jri Slaby <jslaby@suse.cz>
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Werner Fink <werner@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-23 08:14:12 -07:00