Geert, my crosstool don't produce warning below. I guess this has to do
something with compiler version.
- Geert noticed following warning during compilation.
drivers/block/amiflop.c:1344: warning: ‘rq’ may be used uninitialized in
this function
drivers/block/ataflop.c:1402: warning: ‘rq’ may be used uninitialized in
this function
- Initialize rq to NULL to fix the warning. If we can't find a suitable request
to dispatch, this function should return NULL instead of a possibly garbage
pointer.
- Cross compile tested only. Don't have hardware to test it.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
o Currently we try to dispatch more READS and less WRITES (75%, 25%) in one
dispatch round. ummy pointed out that there is a bug in max_nr_writes
calculation. This patch fixes it.
Reported-by: ummy y <yummylln@yahoo.com.cn>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Using:
- CONFIG_LOCKUP_DETECTOR=y
- CONFIG_PREEMPT=y
- CONFIG_LOCKDEP=y
- CONFIG_PROVE_LOCKING=y
- CONFIG_PROVE_RCU=y
found a missing rcu lock during boot on a 512 MiB x86_64 ubuntu vm:
===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
kernel/pid.c:419 invoked rcu_dereference_check() without protection!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 0
1 lock held by ureadahead/1355:
#0: (tasklist_lock){.+.+..}, at: [<ffffffff8115bc09>] sys_ioprio_set+0x7f/0x29e
stack backtrace:
Pid: 1355, comm: ureadahead Not tainted 2.6.37-dbg-DEV #1
Call Trace:
[<ffffffff8109c10c>] lockdep_rcu_dereference+0xaa/0xb3
[<ffffffff81088cbf>] find_task_by_pid_ns+0x44/0x5d
[<ffffffff81088cfa>] find_task_by_vpid+0x22/0x24
[<ffffffff8115bc3e>] sys_ioprio_set+0xb4/0x29e
[<ffffffff8147cf21>] ? trace_hardirqs_off_thunk+0x3a/0x3c
[<ffffffff8105c409>] sysenter_dispatch+0x7/0x2c
[<ffffffff8147cee2>] ? trace_hardirqs_on_thunk+0x3a/0x3f
The fix is to:
a) grab rcu lock in sys_ioprio_{set,get}() and
b) avoid grabbing tasklist_lock.
Discussion in: http://marc.info/?l=linux-kernel&m=128951324702889
Signed-off-by: Greg Thelen <gthelen@google.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Modified by Jens to remove the now redundant inner rcu lock and
unlock since they are now protected by the outer lock.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Remove anticipatory block I/O scheduler info from Documentation/
since the code has been deleted.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Reported-by: "Robert P. J. Day" <rpjday@crashcourse.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
REQ_HARDBARRIER is dead now, so remove the leftovers. What's left
at this point is:
- various checks inside the block layer.
- sanity checks in bio based drivers.
- now unused bio_empty_barrier helper.
- Xen blockfront use of BLKIF_OP_WRITE_BARRIER - it's dead for a while,
but Xen really needs to sort out it's barrier situaton.
- setting of ordered tags in uas - dead code copied from old scsi
drivers.
- scsi different retry for barriers - it's dead and should have been
removed when flushes were converted to FS requests.
- blktrace handling of barriers - removed. Someone who knows blktrace
better should add support for REQ_FLUSH and REQ_FUA, though.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Commit 4221a9918e "Add RCU check for
find_task_by_vpid()" introduced rcu_lockdep_assert to find_task_by_pid_ns=
Assertion failed in sys_ioprio_get. The patch is fixing assertion
failure in ioprio_set as well.
kernel/pid.c:419 invoked rcu_dereference_check() without protection!
stack backtrace:
Pid: 4254, comm: iotop Not tainted
Call Trace:
[<ffffffff810656f2>] lockdep_rcu_dereference+0xaa/0xb2
[<ffffffff81053c67>] find_task_by_pid_ns+0x4f/0x68
[<ffffffff81053c9d>] find_task_by_vpid+0x1d/0x1f
[<ffffffff811104e2>] sys_ioprio_get+0x50/0x2da
[<ffffffff81002182>] system_call_fastpath+0x16/0x1b
V2: rcu critical section expanded according to comment by Paul E. McKenney
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
With 2.6.37-rc1, I observe sys_ioprio_set not taking the RCU lock [1]
across access to the task credentials.
Inspecting the code in fs/ioprio.c, the tasklist_lock is held for read
across the __task_cred call, which is presumably sufficient to prevent
the task credentials becoming stale.
===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
kernel/pid.c:419 invoked rcu_dereference_check() without protection!
other info that might help us debug this:
rcu_scheduler_active = 1, debug_locks = 1
1 lock held by start-stop-daem/2246:
#0: (tasklist_lock){.?.?..}, at: [<ffffffff811a2dfa>]
sys_ioprio_set+0x8a/0x400
stack backtrace:
Pid: 2246, comm: start-stop-daem Not tainted 2.6.37-rc1-330cd+ #2
Call Trace:
[<ffffffff8109f5f4>] lockdep_rcu_dereference+0xa4/0xc0
[<ffffffff81085651>] find_task_by_pid_ns+0x81/0x90
[<ffffffff8108567d>] find_task_by_vpid+0x1d/0x20
[<ffffffff811a3160>] sys_ioprio_set+0x3f0/0x400
[<ffffffff816efa79>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[<ffffffff81003482>] system_call_fastpath+0x16/0x1b
Take the RCU lock for read across acquiring the pointer to the task
credentials and dereferencing it.
Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
Fixed up by Jens to fix missing rcu_read_unlock() on mismatches.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Structure hd_geometry is copied to userland with 4 padding bytes
between cylinders and start fields uninitialized on 64-bit platforms.
It leads to leaking of contents of kernel stack memory.
Currently there is no memset() in real implementations of getgeo()
in drivers/block/, so it makes sense to have memset() in blkdev_ioctl().
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Convert direct reads of an inode's i_size to using i_size_read().
i_size_{read,write} use a seqcount to protect reads from accessing
incomple writes. Concurrent i_size_write()s require mutual exclussion
to protect the seqcount that is used by i_size_{read,write}. But
i_size_read() callers do not need to use additional locking.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: NeilBrown <neilb@suse.de>
Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
If the iovec is being set up in a way that causes uaddr + PAGE_SIZE
to overflow, we could end up attempting to map a huge number of
pages. Check for this invalid input type.
Reported-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Ensure that we pass down properly validated iov segments before
calling into the mapping or copy functions.
Reported-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Commit 27ae60f8f7 ("ipw2x00: replace "ieee80211" with "libipw" where
appropriate") changed DRV_NAME to be "libipw", but didn't properly fix
up the places where it was used to specify the name for the /proc/net/
directory.
For backwards compatibility reasons, that directory name remained
"ieee80211", but due to the DRV_NAME change, the error case printouts
and the cleanup functions now used "libipw" instead. Which made it all
fail badly.
For example, on module unload as reported by Randy:
WARNING: at fs/proc/generic.c:816 remove_proc_entry+0x156/0x35e()
name 'libipw'
because it's trying to unregister a /proc directory that obviously
doesn't even exist.
Clean it all up to use DRV_PROCNAME for the actual /proc directory name.
Reported-and-tested-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Pavel Roskin <proski@gnu.org>
Cc: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: PPC: BookE: Load the lower half of MSR
KVM: PPC: BookE: fix sleep with interrupts disabled
KVM: PPC: e500: Call kvm_vcpu_uninit() before kvmppc_e500_tlb_uninit().
PPC: KVM: Book E doesn't have __end_interrupts.
KVM: x86: Issue smp_call_function_many with preemption disabled
KVM: x86: fix information leak to userland
KVM: PPC: fix information leak to userland
KVM: MMU: fix rmap_remove on non present sptes
KVM: Write protect memory after slot swap
Commit 488211844e ("floppy: switch to one queue per drive instead of
sharing a queue") introduced a use-after-free. We do "put_disk()" on
the disk device _before_ we then clean up the queue associated with that
disk.
Move the put_disk() down to avoid dereferencing a free'd data structure.
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Reported-and-tested-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit d9ca07a05c ("watchdog: Avoid kernel crash when disabling
watchdog") introduces a section mismatch.
Now that we reference no_watchdog from non-__init code it can no longer
be __initdata.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (41 commits)
inet_diag: Make sure we actually run the same bytecode we audited.
netlink: Make nlmsg_find_attr take a const nlmsghdr*.
fib: fib_result_assign() should not change fib refcounts
netfilter: ip6_tables: fix information leak to userspace
cls_cgroup: Fix crash on module unload
memory corruption in X.25 facilities parsing
net dst: fix percpu_counter list corruption and poison overwritten
rds: Remove kfreed tcp conn from list
rds: Lost locking in loop connection freeing
de2104x: fix panic on load
atl1 : fix panic on load
netxen: remove unused firmware exports
caif: Remove noisy printout when disconnecting caif socket
caif: SPI-driver bugfix - incorrect padding.
caif: Bugfix for socket priority, bindtodev and dbg channel.
smsc911x: Set Ethernet EEPROM size to supported device's size
ipv4: netfilter: ip_tables: fix information leak to userland
ipv4: netfilter: arp_tables: fix information leak to userland
cxgb4vf: remove call to stop TX queues at load time.
cxgb4: remove call to stop TX queues at load time.
...
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
firewire: ohci: fix race when reading count in AR descriptor
firewire: ohci: avoid reallocation of AR buffers
firewire: ohci: fix race in AR split packet handling
firewire: ohci: fix buffer overflow in AR split packet handling
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
cifs: make cifs_set_oplock_level() take a cifsInodeInfo pointer
cifs: dereferencing first then checking
cifs: trivial comment fix: tlink_tree is now a rbtree
[CIFS] Cleanup unused variable build warning
cifs: convert tlink_tree to a rbtree
cifs: store pointer to master tlink in superblock (try #2)
cifs: trivial doc fix: note setlease implemented
CIFS: Add cifs_set_oplock_level
FS: cifs, remove unneeded NULL tests
posix-cpu-timers.c correctly assumes that the dying process does
posix_cpu_timers_exit_group() and removes all !CPUCLOCK_PERTHREAD
timers from signal->cpu_timers list.
But, it also assumes that timer->it.cpu.task is always the group
leader, and thus the dead ->task means the dead thread group.
This is obviously not true after de_thread() changes the leader.
After that almost every posix_cpu_timer_ method has problems.
It is not simple to fix this bug correctly. First of all, I think
that timer->it.cpu should use struct pid instead of task_struct.
Also, the locking should be reworked completely. In particular,
tasklist_lock should not be used at all. This all needs a lot of
nontrivial and hard-to-test changes.
Change __exit_signal() to do posix_cpu_timers_exit_group() when
the old leader dies during exec. This is not the fix, just the
temporary hack to hide the problem for 2.6.37 and stable. IOW,
this is obviously wrong but this is what we currently have anyway:
cpu timers do not work after mt exec.
In theory this change adds another race. The exiting leader can
detach the timers which were attached to the new leader. However,
the window between de_thread() and release_task() is small, we
can pretend that sys_timer_create() was called before de_thread().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All the callers already have a pointer to struct cifsInodeInfo. Use it.
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
adapter->id is deprecated and not set by any adapter driver, so this
was certainly not what the author wanted to use. adapter->nr maybe,
but as dev_err() already includes this value, as well as the client's
address, there's no point repeating them. Better print a simple error
message in plain English words.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
arch/tile: mark "hardwall" device as non-seekable
asm-generic/stat.h: support 64-bit file time_t for stat()
arch/tile: don't allow user code to set the PL via ptrace or signal return
arch/tile: correct double syscall restart for nested signals
arch/tile: avoid __must_check warning on one strict_strtol check
arch/tile: bomb raw_local_irq_ to arch_local_irq_
arch/tile: complete migration to new kmap_atomic scheme
Add MODULE_LICENSE() that matches file comments so that kernel
is not tainted.
leds_net5501: module license 'unspecified' taints kernel.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was preventing the guest from setting any bits in the
hardware MSR which aren't forced on, such as MSR[SPE].
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
It is not legal to call mutex_lock() with interrupts disabled.
This will assert with debug checks enabled.
If there's a real need to disable interrupts here, it could be done
after the mutex is acquired -- but I don't see why it's needed at all.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Reviewed-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
The VCPU uninit calls some TLB functions, and the TLB uninit function
frees the memory used by them.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Fix an unresolved symbol with CONFIG_KVM_GUEST plus CONFIG_RELOCATABLE on
Book E.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
smp_call_function_many is specified to be called only with preemption
disabled. Fulfill this requirement.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Structures kvm_vcpu_events, kvm_debugregs, kvm_pit_state2 and
kvm_clock_data are copied to userland with some padding and reserved
fields unitialized. It leads to leaking of contents of kernel stack
memory. We have to initialize them to zero.
In patch v1 Jan Kiszka suggested to fill reserved fields with zeros
instead of memset'ting the whole struct. It makes sense as these
fields are explicitly marked as padding. No more fields need zeroing.
KVM-Stable-Tag.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Structure kvm_ppc_pvinfo is copied to userland with flags and
pad fields unitialized. It leads to leaking of contents of
kernel stack memory.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
drop_spte should not attempt to rmap_remove a non present shadow pte.
This fixes a BUG_ON seen on kvm-autotest.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Reported-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
I have observed the following bug trigger:
1. userspace calls GET_DIRTY_LOG
2. kvm_mmu_slot_remove_write_access is called and makes a page ro
3. page fault happens and makes the page writeable
fault is logged in the bitmap appropriately
4. kvm_vm_ioctl_get_dirty_log swaps slot pointers
a lot of time passes
5. guest writes into the page
6. userspace calls GET_DIRTY_LOG
At point (5), bitmap is clean and page is writeable,
thus, guest modification of memory is not logged
and GET_DIRTY_LOG returns an empty bitmap.
The rule is that all pages are either dirty in the current bitmap,
or write-protected, which is violated here.
It seems that just moving kvm_mmu_slot_remove_write_access down
to after the slot pointer swap should fix this bug.
KVM-Stable-Tag.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
We can optimize kernel/relay.c::relay_alloc_page_array() slightly by
using vzalloc. The patch makes these changes:
- use vzalloc instead of vmalloc+memset.
- remove redundant local variable 'array'.
- declare local 'pa_size' as const.
Cuts down nicely on both source and object-code size.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
m68k, m68knommu: Do not include linux/hardirq.h in asm/irqflags.h
m68knommu: add back in declaration of do_IRQ
This patch is based on Dan's original patch. His original description is
below:
Smatch complained about a couple checking for NULL after dereferencing
bugs. I'm not super familiar with the code so I did the conservative
thing and move the dereferences after the checks.
The dereferences in cifs_lock() and cifs_fsync() were added in
ba00ba64cf "cifs: make various routines use the cifsFileInfo->tcon
pointer". The dereference in find_writable_file() was added in
6508d904e6 "cifs: have find_readable/writable_file filter by fsuid".
The comments there say it's possible to trigger the NULL dereference
under stress.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Noticed while reviewing (late) the rbtree conversion patchset (which has been merged
already).
Cc: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We were using nlmsg_find_attr() to look up the bytecode by attribute when
auditing, but then just using the first attribute when actually running
bytecode. So, if we received a message with two attribute elements, where only
the second had type INET_DIAG_REQ_BYTECODE, we would validate and run different
bytecode strings.
Fix this by consistently using nlmsg_find_attr everywhere.
Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Signed-off-by: Thomas Graf <tgraf@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This will let us use it on a nlmsghdr stored inside a netlink_callback.
Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit ebc0ffae5 (RCU conversion of fib_lookup()),
fib_result_assign() should not change fib refcounts anymore.
Thanks to Michael who did the bisection and bug report.
Reported-by: Michael Ellerman <michael@ellerman.id.au>
Tested-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Somewhere along the lines net_cls_subsys_id became a macro when
cls_cgroup is built as a module. Not only did it make cls_cgroup
completely useless, it also causes it to crash on module unload.
This patch fixes this by removing that macro.
Thanks to Eric Dumazet for diagnosing this problem.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
