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commit 4b20db3de8dab005b07c74161cb041db8c5ff3a7 upstream.
This function is intended to simplify locking around refcounting for
objects that can be looked up from a lookup structure, and which are
removed from that lookup structure in the object destructor.
Operations on such objects require at least a read lock around
lookup + kref_get, and a write lock around kref_put + remove from lookup
structure. Furthermore, RCU implementations become extremely tricky.
With a lookup followed by a kref_get_unless_zero *with return value check*
locking in the kref_put path can be deferred to the actual removal from
the lookup structure and RCU lookups become trivial.
v2: Formatting fixes.
v3: Invert the return value.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 386afc91144b36b42117b0092893f15bc8798a80 upstream.
In UP and non-preempt respectively, the spinlocks and preemption
disable/enable points are stubbed out entirely, because there is no
regular code that can ever hit the kind of concurrency they are meant to
protect against.
However, while there is no regular code that can cause scheduling, we
_do_ end up having some exceptional (literally!) code that can do so,
and that we need to make sure does not ever get moved into the critical
region by the compiler.
In particular, get_user() and put_user() is generally implemented as
inline asm statements (even if the inline asm may then make a call
instruction to call out-of-line), and can obviously cause a page fault
and IO as a result. If that inline asm has been scheduled into the
middle of a preemption-safe (or spinlock-protected) code region, we
obviously lose.
Now, admittedly this is *very* unlikely to actually ever happen, and
we've not seen examples of actual bugs related to this. But partly
exactly because it's so hard to trigger and the resulting bug is so
subtle, we should be extra careful to get this right.
So make sure that even when preemption is disabled, and we don't have to
generate any actual *code* to explicitly tell the system that we are in
a preemption-disabled region, we need to at least tell the compiler not
to move things around the critical region.
This patch grew out of the same discussion that caused commits
79e5f05edcbf ("ARC: Add implicit compiler barrier to raw_local_irq*
functions") and 3e2e0d2c222b ("tile: comment assumption about
__insn_mtspr for <asm/irqflags.h>") to come about.
Note for stable: use discretion when/if applying this. As mentioned,
this bug may never have actually bitten anybody, and gcc may never have
done the required code motion for it to possibly ever trigger in
practice.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit a32450e127fc6e5ca6d958ceb3cfea4d30a00846 upstream.
The Slimtype DVD A DS8A8SH drive locks up when max sector is smaller than
65535, and the blow backtrace is observed on locking up:
INFO: task flush-8:32:1130 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
flush-8:32 D ffffffff8180cf60 0 1130 2 0x00000000
ffff880273aef618 0000000000000046 0000000000000005 ffff880273aee000
ffff880273aee000 ffff880273aeffd8 ffff880273aee010 ffff880273aee000
ffff880273aeffd8 ffff880273aee000 ffff88026e842ea0 ffff880274a10000
Call Trace:
[<ffffffff8168fc2d>] schedule+0x5d/0x70
[<ffffffff8168fccc>] io_schedule+0x8c/0xd0
[<ffffffff81324461>] get_request+0x731/0x7d0
[<ffffffff8133dc60>] ? cfq_allow_merge+0x50/0x90
[<ffffffff81083aa0>] ? wake_up_bit+0x40/0x40
[<ffffffff81320443>] ? bio_attempt_back_merge+0x33/0x110
[<ffffffff813248ea>] blk_queue_bio+0x23a/0x3f0
[<ffffffff81322176>] generic_make_request+0xc6/0x120
[<ffffffff81322308>] submit_bio+0x138/0x160
[<ffffffff811d7596>] ? bio_alloc_bioset+0x96/0x120
[<ffffffff811d1f61>] submit_bh+0x1f1/0x220
[<ffffffff811d48b8>] __block_write_full_page+0x228/0x340
[<ffffffff811d3650>] ? attach_nobh_buffers+0xc0/0xc0
[<ffffffff811d8960>] ? I_BDEV+0x10/0x10
[<ffffffff811d8960>] ? I_BDEV+0x10/0x10
[<ffffffff811d4ab6>] block_write_full_page_endio+0xe6/0x100
[<ffffffff811d4ae5>] block_write_full_page+0x15/0x20
[<ffffffff811d9268>] blkdev_writepage+0x18/0x20
[<ffffffff81142527>] __writepage+0x17/0x40
[<ffffffff811438ba>] write_cache_pages+0x34a/0x4a0
[<ffffffff81142510>] ? set_page_dirty+0x70/0x70
[<ffffffff81143a61>] generic_writepages+0x51/0x80
[<ffffffff81143ab0>] do_writepages+0x20/0x50
[<ffffffff811c9ed6>] __writeback_single_inode+0xa6/0x2b0
[<ffffffff811ca861>] writeback_sb_inodes+0x311/0x4d0
[<ffffffff811caaa6>] __writeback_inodes_wb+0x86/0xd0
[<ffffffff811cad43>] wb_writeback+0x1a3/0x330
[<ffffffff816916cf>] ? _raw_spin_lock_irqsave+0x3f/0x50
[<ffffffff811b8362>] ? get_nr_inodes+0x52/0x70
[<ffffffff811cb0ac>] wb_do_writeback+0x1dc/0x260
[<ffffffff8168dd34>] ? schedule_timeout+0x204/0x240
[<ffffffff811cb232>] bdi_writeback_thread+0x102/0x2b0
[<ffffffff811cb130>] ? wb_do_writeback+0x260/0x260
[<ffffffff81083550>] kthread+0xc0/0xd0
[<ffffffff81083490>] ? kthread_worker_fn+0x1b0/0x1b0
[<ffffffff8169a3ec>] ret_from_fork+0x7c/0xb0
[<ffffffff81083490>] ? kthread_worker_fn+0x1b0/0x1b0
The above trace was triggered by
"dd if=/dev/zero of=/dev/sr0 bs=2048 count=32768"
It was previously working by accident, since another bug introduced
by 4dce8ba94c7 (libata: Use 'bool' return value for ata_id_XXX) caused
all drives to use maxsect=65535.
Signed-off-by: Shan Hai <shan.hai@windriver.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit d8668fcb0b257d9fdcfbe5c172a99b8d85e1cd82 upstream.
The function returns type of ATAPI drives so it should return integer value.
The commit 4dce8ba94c7 (libata: Use 'bool' return value for ata_id_XXX) since
v2.6.39 changed the type of return value from int to bool, the change would
cause all of the ATAPI class drives to be treated as TYPE_TAPE and the
max_sectors of the drives to be set to 65535 because of the commit
f8d8e5799b7(libata: increase 128 KB / cmd limit for ATAPI tape drives), for the
function would return true for all ATAPI class drives and the TYPE_TAPE is
defined as 0x01.
Signed-off-by: Shan Hai <shan.hai@windriver.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit ae5fc98728c8bbbd6d7cab0b9781671fc4419c1b ]
Follow the common pattern and define *_DIAG_MAX like:
[...]
__XXX_DIAG_MAX,
};
Because everyone is used to do:
struct nlattr *attrs[XXX_DIAG_MAX+1];
nla_parse([...], XXX_DIAG_MAX, [...]
Reported-by: Thomas Graf <tgraf@suug.ch>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commits 73214f5d9f33b79918b1f7babddd5c8af28dd23d
and f1e79e208076ffe7bad97158275f1c572c04f5c7, the latter
adds an assertion to genetlink to prevent this from happening
again in the future. ]
The original name is too long.
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit d740269867021faf4ce38a449353d2b986c34a67 upstream.
To avoid an explosion of request_module calls on a chain of abusive
scripts, fail maximum recursion with -ELOOP instead of -ENOEXEC. As soon
as maximum recursion depth is hit, the error will fail all the way back
up the chain, aborting immediately.
This also has the side-effect of stopping the user's shell from attempting
to reexecute the top-level file as a shell script. As seen in the
dash source:
if (cmd != path_bshell && errno == ENOEXEC) {
*argv-- = cmd;
*argv = cmd = path_bshell;
goto repeat;
}
The above logic was designed for running scripts automatically that lacked
the "#!" header, not to re-try failed recursion. On a legitimate -ENOEXEC,
things continue to behave as the shell expects.
Additionally, when tracking recursion, the binfmt handlers should not be
involved. The recursion being tracked is the depth of calls through
search_binary_handler(), so that function should be exclusively responsible
for tracking the depth.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: halfdog <me@halfdog.net>
Cc: P J P <ppandit@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 16fad69cfe4adbbfa813de516757b87bcae36d93 ]
Chrome OS team reported a crash on a Pixel ChromeBook in TCP stack :
https://code.google.com/p/chromium/issues/detail?id=182056
commit a21d45726acac (tcp: avoid order-1 allocations on wifi and tx
path) did a poor choice adding an 'avail_size' field to skb, while
what we really needed was a 'reserved_tailroom' one.
It would have avoided commit 22b4a4f22da (tcp: fix retransmit of
partially acked frames) and this commit.
Crash occurs because skb_split() is not aware of the 'avail_size'
management (and should not be aware)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Mukesh Agrawal <quiche@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 6c4d3bc99b3341067775efd4d9d13cc8e655fd7c upstream.
Commit 1d9d8639c063 ("perf,x86: fix kernel crash with PEBS/BTS after
suspend/resume") introduces a link failure since
perf_restore_debug_store() is only defined for CONFIG_CPU_SUP_INTEL:
arch/x86/power/built-in.o: In function `restore_processor_state':
(.text+0x45c): undefined reference to `perf_restore_debug_store'
Fix it by defining the dummy function appropriately.
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1d9d8639c063caf6efc2447f5f26aa637f844ff6 upstream.
This patch fixes a kernel crash when using precise sampling (PEBS)
after a suspend/resume. Turns out the CPU notifier code is not invoked
on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly
by the kernel and keeps it power-on/resume value of 0 causing any PEBS
measurement to crash when running on CPU0.
The workaround is to add a hook in the actual resume code to restore
the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0,
the DS_AREA will be restored twice but this is harmless.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 9f244e9cfd70c7c0f82d3c92ce772ab2a92d9f64 upstream.
[Issue]
When pstore is in panic and emergency-restart paths, it may be blocked
in those paths because it simply takes spin_lock.
This is an example scenario which pstore may hang up in a panic path:
- cpuA grabs psinfo->buf_lock
- cpuB panics and calls smp_send_stop
- smp_send_stop sends IRQ to cpuA
- after 1 second, cpuB gives up on cpuA and sends an NMI instead
- cpuA is now in an NMI handler while still holding buf_lock
- cpuB is deadlocked
This case may happen if a firmware has a bug and
cpuA is stuck talking with it more than one second.
Also, this is a similar scenario in an emergency-restart path:
- cpuA grabs psinfo->buf_lock and stucks in a firmware
- cpuB kicks emergency-restart via either sysrq-b or hangcheck timer.
And then, cpuB is deadlocked by taking psinfo->buf_lock again.
[Solution]
This patch avoids the deadlocking issues in both panic and emergency_restart
paths by introducing a function, is_non_blocking_path(), to check if a cpu
can be blocked in current path.
With this patch, pstore is not blocked even if another cpu has
taken a spin_lock, in those paths by changing from spin_lock_irqsave
to spin_trylock_irqsave.
In addition, according to a comment of emergency_restart() in kernel/sys.c,
spin_lock shouldn't be taken in an emergency_restart path to avoid
deadlock. This patch fits the comment below.
<snip>
/**
* emergency_restart - reboot the system
*
* Without shutting down any hardware or taking any locks
* reboot the system. This is called when we know we are in
* trouble so this is our best effort to reboot. This is
* safe to call in interrupt context.
*/
void emergency_restart(void)
<snip>
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: CAI Qian <caiqian@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 4f4ffc3a5398ef9bdbb32db04756d7d34e356fcf upstream.
automount-support is broken on the parisc architecture, because the existing
#if list does not include a check for defined(__hppa__). The HPPA (parisc)
architecture is similiar to other 64bit Linux targets where we have to define
autofs_wqt_t (which is passed back and forth to user space) as int type which
has a size of 32bit across 32 and 64bit kernels.
During the discussion on the mailing list, H. Peter Anvin suggested to invert
the #if list since only specific platforms (specifically those who do not have
a 32bit userspace, like IA64 and Alpha) should have autofs_wqt_t as unsigned
long type.
This suggestion is probably the best way to go, since Arm64 (and maybe others?)
seems to have a non-working automounter. So in the long run even for other new
upcoming architectures this inverted check seem to be the best solution, since
it will not require them to change this #if again (unless they are 64bit only).
Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Ian Kent <raven@themaw.net>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
CC: James Bottomley <James.Bottomley@HansenPartnership.com>
CC: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c3ad83d9efdfe6a86efd44945a781f00c879b7b4 upstream.
Otherwise, ext4 file systems with the quota featured enable will get a
very confusing "No such process" error message if the quota code is
built as a module and the quota_v2 module has not been loaded.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit da8c87241c26aac81a64c7e4d21d438a33018f4e ]
There are two places to call vlan_set_encap_proto():
vlan_untag() and __pop_vlan_tci().
vlan_untag() assumes skb->data points after mac addr, otherwise
the following code
vhdr = (struct vlan_hdr *) skb->data;
vlan_tci = ntohs(vhdr->h_vlan_TCI);
__vlan_hwaccel_put_tag(skb, vlan_tci);
skb_pull_rcsum(skb, VLAN_HLEN);
won't be correct. But __pop_vlan_tci() assumes points _before_
mac addr.
In vlan_set_encap_proto(), it looks for some magic L2 value
after mac addr:
rawp = skb->data;
if (*(unsigned short *) rawp == 0xFFFF)
...
Therefore __pop_vlan_tci() is obviously wrong.
A quick fix is avoiding using skb->data in vlan_set_encap_proto(),
use 'vhdr+1' is always correct in both cases.
Signed-off-by: Cong Wang <amwang@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jesse Gross <jesse@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e93a9a868792ad71cdd09d75e5a02d8067473c4e upstream.
I've still got lockdep warnings even after Alan's patch, and it seems that
yet more band aids are required to paper over similar paths for
unbind_con_driver() and unregister_con_driver(). After this hack, lockdep
warnings are finally gone.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 50e244cc793d511b86adea24972f3a7264cae114 upstream.
Adjust the console layer to allow a take over call where the caller
already holds the locks. Make the fb layer lock in order.
This is partly a band aid, the fb layer is terminally confused about the
locking rules it uses for its notifiers it seems.
[akpm@linux-foundation.org: remove stray non-ascii char, tidy comment]
[akpm@linux-foundation.org: export do_take_over_console()]
[airlied: cleanup another non-ascii char]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Jiri Kosina <jkosina@suse.cz>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 2a2483072393b27f4336ab068a1f48ca19ff1c1e upstream.
When we switch from 256->512 byte font rendering mode, it means the
current contents of the screen is being reinterpreted. The bit that holds
the high bit of the 9-bit font, may have been previously set, and thus
the new font misrenders.
The problem case we see is grub2 writes spaces with the bit set, so it
ends up with data like 0x820, which gets reinterpreted into 0x120 char
which the font translates into G with a circumflex. This flashes up on
screen at boot and is quite ugly.
A current side effect of this patch though is that any rendering on the
screen changes color to a slightly darker color, but at least the screen
no longer corrupts.
v2: as suggested by hpa, always clear the attribute space, whether we
are are going to or from 512 chars.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b531f81b0d70ffbe8d70500512483227cc532608 upstream.
Commit 99fc86450c439039d2ef88d06b222fd51a779176 "ALSA: usb-mixer:
parse descriptors with structs" introduced a set of useful parsers
for descriptors. Unfortunately the parses for the Processing Unit
Descriptor came with a very subtle bug...
Functions uac_processing_unit_iProcessing() and
uac_processing_unit_specific() were indexing the baSourceID array
forgetting the fields before the iProcessing and process-specific
descriptors.
The problem was observed with Sound Blaster Extigy mixer,
where nNrModes in Up/Down-mix Processing Unit Descriptor
was accessed at offset 10 of the descriptor (value 0)
instead of offset 15 (value 7). In result the resulting
control had interesting limit values:
Simple mixer control 'Channel Routing Mode Select',0
Capabilities: volume volume-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - -1
Mono: -1 [100%]
Fixed by starting from the bmControls, which was calculated
correctly, instead of baSourceID.
Now the mentioned control is fine:
Simple mixer control 'Channel Routing Mode Select',0
Capabilities: volume volume-joined penum
Playback channels: Mono
Capture channels: Mono
Limits: 0 - 6
Mono: 0 [0%]
Signed-off-by: Pawel Moll <mail@pawelmoll.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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schedule
commit 21a92735f660eaecf69a6f2e777f18463760ec32 upstream.
With an RCU based mmu_notifier implementation, any callout to
mmu_notifier_invalidate_range_{start,end}() or
mmu_notifier_invalidate_page() would not be allowed to call schedule()
as that could potentially allow a modification to the mmu_notifier
structure while it is currently being used.
Since srcu allocs 4 machine words per instance per cpu, we may end up
with memory exhaustion if we use srcu per mm. So all mms share a global
srcu. Note that during large mmu_notifier activity exit & unregister
paths might hang for longer periods, but it is tolerable for current
mmu_notifier clients.
Signed-off-by: Sagi Grimberg <sagig@mellanox.co.il>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Haggai Eran <haggaie@mellanox.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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call_console_drivers
This patch corrects a buffer overflow in kernels from 3.0 to 3.4 when calling
log_prefix() function from call_console_drivers().
This bug existed in previous releases but has been revealed with commit
162a7e7500f9664636e649ba59defe541b7c2c60 (2.6.39 => 3.0) that made changes
about how to allocate memory for early printk buffer (use of memblock_alloc).
It disappears with commit 7ff9554bb578ba02166071d2d487b7fc7d860d62 (3.4 => 3.5)
that does a refactoring of printk buffer management.
In log_prefix(), the access to "p[0]", "p[1]", "p[2]" or
"simple_strtoul(&p[1], &endp, 10)" may cause a buffer overflow as this
function is called from call_console_drivers by passing "&LOG_BUF(cur_index)"
where the index must be masked to do not exceed the buffer's boundary.
The trick is to prepare in call_console_drivers() a buffer with the necessary
data (PRI field of syslog message) to be safely evaluated in log_prefix().
This patch can be applied to stable kernel branches 3.0.y, 3.2.y and 3.4.y.
Without this patch, one can freeze a server running this loop from shell :
$ export DUMMY=`cat /dev/urandom | tr -dc '12345AZERTYUIOPQSDFGHJKLMWXCVBNazertyuiopqsdfghjklmwxcvbn' | head -c255`
$ while true do ; echo $DUMMY > /dev/kmsg ; done
The "server freeze" depends on where memblock_alloc does allocate printk buffer :
if the buffer overflow is inside another kernel allocation the problem may not
be revealed, else the server may hangs up.
Signed-off-by: Alexandre SIMON <Alexandre.Simon@univ-lorraine.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 83e68189745ad931c2afd45d8ee3303929233e7f upstream.
Originally 'efi_enabled' indicated whether a kernel was booted from
EFI firmware. Over time its semantics have changed, and it now
indicates whether or not we are booted on an EFI machine with
bit-native firmware, e.g. 64-bit kernel with 64-bit firmware.
The immediate motivation for this patch is the bug report at,
https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557
which details how running a platform driver on an EFI machine that is
designed to run under BIOS can cause the machine to become
bricked. Also, the following report,
https://bugzilla.kernel.org/show_bug.cgi?id=47121
details how running said driver can also cause Machine Check
Exceptions. Drivers need a new means of detecting whether they're
running on an EFI machine, as sadly the expression,
if (!efi_enabled)
hasn't been a sufficient condition for quite some time.
Users actually want to query 'efi_enabled' for different reasons -
what they really want access to is the list of available EFI
facilities.
For instance, the x86 reboot code needs to know whether it can invoke
the ResetSystem() function provided by the EFI runtime services, while
the ACPI OSL code wants to know whether the EFI config tables were
mapped successfully. There are also checks in some of the platform
driver code to simply see if they're running on an EFI machine (which
would make it a bad idea to do BIOS-y things).
This patch is a prereq for the samsung-laptop fix patch.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Peter Jones <pjones@redhat.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Steve Langasek <steve.langasek@canonical.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 54a3ac0c9e5b7213daa358ce74d154352657353a upstream.
Usb3.0 device defines function remote wakeup which is only for interface
recipient rather than device recipient. This is different with usb2.0 device's
remote wakeup feature which is defined for device recipient. According usb3.0
spec 9.4.5, the function remote wakeup can be modified by the SetFeature()
requests using the FUNCTION_SUSPEND feature selector. This patch is to use
correct way to disable usb3.0 device's function remote wakeup after suspend
error and resuming.
This should be backported to kernels as old as 3.4, that contain the
commit 623bef9e03a60adc623b09673297ca7a1cdfb367 "USB/xhci: Enable remote
wakeup for USB3 devices."
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 910ffdb18a6408e14febbb6e4b6840fd2c928c82 upstream.
Cleanup and preparation for the next change.
signal_wake_up(resume => true) is overused. None of ptrace/jctl callers
actually want to wakeup a TASK_WAKEKILL task, but they can't specify the
necessary mask.
Turn signal_wake_up() into signal_wake_up_state(state), reintroduce
signal_wake_up() as a trivial helper, and add ptrace_signal_wake_up()
which adds __TASK_TRACED.
This way ptrace_signal_wake_up() can work "inside" ptrace_request()
even if the tracee doesn't have the TASK_WAKEKILL bit set.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This would reset a connection with any OSD that had an outstanding
request that was taking more than N seconds. The idea was that if the
OSD was buggy, the client could compensate by resending the request.
In reality, this only served to hide server bugs, and we haven't
actually seen such a bug in quite a while. Moreover, the userspace
client code never did this.
More importantly, often the request is taking a long time because the
OSD is trying to recover, or overloaded, and killing the connection
and retrying would only make the situation worse by giving the OSD
more work to do.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
(cherry picked from commit 83aff95eb9d60aff5497e9f44a2ae906b86d8e88)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 812089e01b9f65f90fc8fc670d8cce72a0e01fbb upstream.
Otherwise it fails like this on cards like the Transcend 16GB SDHC card:
mmc0: new SDHC card at address b368
mmcblk0: mmc0:b368 SDC 15.0 GiB
mmcblk0: error -110 sending status command, retrying
mmcblk0: error -84 transferring data, sector 0, nr 8, cmd response 0x900, card status 0xb0
Tested on my Lenovo x200 laptop.
[bhelgaas: changelog]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Chris Ball <cjb@laptop.org>
CC: Manoj Iyer <manoj.iyer@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 0c24604b68fc7810d429d6c3657b6f148270e528 ]
Implement the RFC 5691 mitigation against Blind
Reset attack using SYN bit.
Section 4.2 of RFC 5961 advises to send a Challenge ACK and drop
incoming packet, instead of resetting the session.
Add a new SNMP counter to count number of challenge acks sent
in response to SYN packets.
(netstat -s | grep TCPSYNChallenge)
Remove obsolete TCPAbortOnSyn, since we no longer abort a TCP session
because of a SYN flag.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kiran Kumar Kella <kkiran@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 282f23c6ee343126156dd41218b22ece96d747e3 ]
Implement the RFC 5691 mitigation against Blind
Reset attack using RST bit.
Idea is to validate incoming RST sequence,
to match RCV.NXT value, instead of previouly accepted
window : (RCV.NXT <= SEG.SEQ < RCV.NXT+RCV.WND)
If sequence is in window but not an exact match, send
a "challenge ACK", so that the other part can resend an
RST with the appropriate sequence.
Add a new sysctl, tcp_challenge_ack_limit, to limit
number of challenge ACK sent per second.
Add a new SNMP counter to count number of challenge acks sent.
(netstat -s | grep TCPChallengeACK)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kiran Kumar Kella <kkiran@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit dd67d32dbc5de299d70cc9e10c6c1e29ffa56b92 upstream.
A task is considered frozen enough between freezer_do_not_count() and
freezer_count() and freezers use freezer_should_skip() to test this
condition. This supposedly works because freezer_count() always calls
try_to_freezer() after clearing %PF_FREEZER_SKIP.
However, there currently is nothing which guarantees that
freezer_count() sees %true freezing() after clearing %PF_FREEZER_SKIP
when freezing is in progress, and vice-versa. A task can escape the
freezing condition in effect by freezer_count() seeing !freezing() and
freezer_should_skip() seeing %PF_FREEZER_SKIP.
This patch adds smp_mb()'s to freezer_count() and
freezer_should_skip() such that either %true freezing() is visible to
freezer_count() or !PF_FREEZER_SKIP is visible to
freezer_should_skip().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ad4b3fb7ff9940bcdb1e4cd62bd189d10fa636ba upstream.
Unfortunately with !CONFIG_PAGEFLAGS_EXTENDED, (!PageHead) is false, and
(PageHead) is true, for tail pages. If this is indeed the intended
behavior, which I doubt because it breaks cache cleaning on some ARM
systems, then the nomenclature is highly problematic.
This patch makes sure PageHead is only true for head pages and PageTail
is only true for tail pages, and neither is true for non-compound pages.
[ This buglet seems ancient - seems to have been introduced back in Apr
2008 in commit 6a1e7f777f61: "pageflags: convert to the use of new
macros". And the reason nobody noticed is because the PageHead()
tests are almost all about just sanity-checking, and only used on
pages that are actual page heads. The fact that the old code returned
true for tail pages too was thus not really noticeable. - Linus ]
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Will Deacon <Will.Deacon@arm.com>
Cc: Steve Capper <Steve.Capper@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b66c5984017533316fd1951770302649baf1aa33 upstream.
If a series of scripts are executed, each triggering module loading via
unprintable bytes in the script header, kernel stack contents can leak
into the command line.
Normally execution of binfmt_script and binfmt_misc happens recursively.
However, when modules are enabled, and unprintable bytes exist in the
bprm->buf, execution will restart after attempting to load matching
binfmt modules. Unfortunately, the logic in binfmt_script and
binfmt_misc does not expect to get restarted. They leave bprm->interp
pointing to their local stack. This means on restart bprm->interp is
left pointing into unused stack memory which can then be copied into the
userspace argv areas.
After additional study, it seems that both recursion and restart remains
the desirable way to handle exec with scripts, misc, and modules. As
such, we need to protect the changes to interp.
This changes the logic to require allocation for any changes to the
bprm->interp. To avoid adding a new kmalloc to every exec, the default
value is left as-is. Only when passing through binfmt_script or
binfmt_misc does an allocation take place.
For a proof of concept, see DoTest.sh from:
http://www.halfdog.net/Security/2012/LinuxKernelBinfmtScriptStackDataDisclosure/
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: halfdog <me@halfdog.net>
Cc: P J P <ppandit@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 18a2f371f5edf41810f6469cb9be39931ef9deb9 upstream.
This fixes a regression in 3.7-rc, which has since gone into stable.
Commit 00442ad04a5e ("mempolicy: fix a memory corruption by refcount
imbalance in alloc_pages_vma()") changed get_vma_policy() to raise the
refcount on a shmem shared mempolicy; whereas shmem_alloc_page() went
on expecting alloc_page_vma() to drop the refcount it had acquired.
This deserves a rework: but for now fix the leak in shmem_alloc_page().
Hugh: shmem_swapin() did not need a fix, but surely it's clearer to use
the same refcounting there as in shmem_alloc_page(), delete its onstack
mempolicy, and the strange mpol_cond_copy() and __mpol_cond_copy() -
those were invented to let swapin_readahead() make an unknown number of
calls to alloc_pages_vma() with one mempolicy; but since 00442ad04a5e,
alloc_pages_vma() has kept refcount in balance, so now no problem.
Reported-and-tested-by: Tommi Rantala <tt.rantala@gmail.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 261030215d970c62f799e6e508e3c68fc7ec2aa9 upstream.
For some reason the declaration of ceph_con_get() and
ceph_con_put() did not get deleted in this commit:
d59315ca libceph: drop ceph_con_get/put helpers and nref member
Clean that up.
Signed-off-by: Alex Elder <elder@inktank.com>
Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit d63b77f4c552cc3a20506871046ab0fcbc332609)
If we encounter an invalid (e.g., zeroed) mapping, return an error
and avoid a divide by zero.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit 4a8616920860920abaa51193146fe36b38ef09aa)
Rename flags with CON_FLAG prefix, move the definitions into the c file,
and (better) document their meaning.
Signed-off-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit 8dacc7da69a491c515851e68de6036f21b5663ce)
Use a simple set of 6 enumerated values for the socket states (CON_STATE_*)
and use those instead of the state bits. All of the con->state checks are
now under the protection of the con mutex, so this is safe. It also
simplifies many of the state checks because we can check for anything other
than the expected state instead of various bits for races we can think of.
This appears to hold up well to stress testing both with and without socket
failure injection on the server side.
Signed-off-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit a2a3258417eb6a1799cf893350771428875a8287)
Add an atomic variable 'stopping' as flag in struct ceph_messenger,
set this flag to 1 in function ceph_destroy_client(), and add the condition code
in function ceph_data_ready() to test the flag value, if true(1), just return.
Signed-off-by: Guanjun He <gjhe@suse.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit d50b409fb8698571d8209e5adfe122e287e31290)
Initialize the type field for messages in a msgpool. The caller was doing
this for osd ops, but not for the reply messages.
Reported-by: Alex Elder <elder@inktank.com>
Signed-off-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit b7a9e5dd40f17a48a72f249b8bbc989b63bae5fd)
The peer name may change on each open attempt, even when the connection is
reused.
Signed-off-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit e27947c767f5bed15048f4e4dad3e2eb69133697)
There is no state explicitly defined when a ceph connection is fully
operational. So define one.
It's set when the connection sequence completes successfully, and is
cleared when the connection gets closed.
Be a little more careful when examining the old state when a socket
disconnect event is reported.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit d59315ca8c0de00df9b363f94a2641a30961ca1c)
These are no longer used. Every ceph_connection instance is embedded in
another structure, and refcounts manipulated via the get/put ops.
Signed-off-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit 8921d114f5574c6da2cdd00749d185633ecf88f3)
ceph_con_revoke_message() is passed both a message and a ceph
connection. A ceph_msg allocated for incoming messages on a
connection always has a pointer to that connection, so there's no
need to provide the connection when revoking such a message.
Note that the existing logic does not preclude the message supplied
being a null/bogus message pointer. The only user of this interface
is the OSD client, and the only value an osd client passes is a
request's r_reply field. That is always non-null (except briefly in
an error path in ceph_osdc_alloc_request(), and that drops the
only reference so the request won't ever have a reply to revoke).
So we can safely assume the passed-in message is non-null, but add a
BUG_ON() to make it very obvious we are imposing this restriction.
Rename the function ceph_msg_revoke_incoming() to reflect that it is
really an operation on an incoming message.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit 6740a845b2543cc46e1902ba21bac743fbadd0dc)
ceph_con_revoke() is passed both a message and a ceph connection.
Now that any message associated with a connection holds a pointer
to that connection, there's no need to provide the connection when
revoking a message.
This has the added benefit of precluding the possibility of the
providing the wrong connection pointer. If the message's connection
pointer is null, it is not being tracked by any connection, so
revoking it is a no-op. This is supported as a convenience for
upper layers, so they can revoke a message that is not actually
"in flight."
Rename the function ceph_msg_revoke() to reflect that it is really
an operation on a message, not a connection.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit 38941f8031bf042dba3ced6394ba3a3b16c244ea)
When a ceph message is queued for sending it is placed on a list of
pending messages (ceph_connection->out_queue). When they are
actually sent over the wire, they are moved from that list to
another (ceph_connection->out_sent). When acknowledgement for the
message is received, it is removed from the sent messages list.
During that entire time the message is "in the possession" of a
single ceph connection. Keep track of that connection in the
message. This will be used in the next patch (and is a helpful
bit of information for debugging anyway).
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit 1bfd89f4e6e1adc6a782d94aa5d4c53be1e404d7)
Move the initialization of a ceph connection's private pointer,
operations vector pointer, and peer name information into
ceph_con_init(). Rearrange the arguments so the connection pointer
is first. Hide the byte-swapping of the peer entity number inside
ceph_con_init()
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit 67130934fb579fdf0f2f6d745960264378b57dc8)
A monitor client has a pointer to a ceph connection structure in it.
This is the only one of the three ceph client types that do it this
way; the OSD and MDS clients embed the connection into their main
structures. There is always exactly one ceph connection for a
monitor client, so there is no need to allocate it separate from the
monitor client structure.
So switch the ceph_mon_client structure to embed its
ceph_connection structure.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit ce2c8903e76e690846a00a0284e4bd9ee954d680)
Start explicitly keeping track of the state of a ceph connection's
socket, separate from the state of the connection itself. Create
placeholder functions to encapsulate the state transitions.
--------
| NEW* | transient initial state
--------
| con_sock_state_init()
v
----------
| CLOSED | initialized, but no socket (and no
---------- TCP connection)
^ \
| \ con_sock_state_connecting()
| ----------------------
| \
+ con_sock_state_closed() \
|\ \
| \ \
| ----------- \
| | CLOSING | socket event; \
| ----------- await close \
| ^ |
| | |
| + con_sock_state_closing() |
| / \ |
| / --------------- |
| / \ v
| / --------------
| / -----------------| CONNECTING | socket created, TCP
| | / -------------- connect initiated
| | | con_sock_state_connected()
| | v
-------------
| CONNECTED | TCP connection established
-------------
Make the socket state an atomic variable, reinforcing that it's a
distinct transtion with no possible "intermediate/both" states.
This is almost certainly overkill at this point, though the
transitions into CONNECTED and CLOSING state do get called via
socket callback (the rest of the transitions occur with the
connection mutex held). We can back out the atomicity later.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil<sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit 928443cd9644e7cfd46f687dbeffda2d1a357ff9)
A ceph_connection holds a mixture of connection state (as in "state
machine" state) and connection flags in a single "state" field. To
make the distinction more clear, define a new "flags" field and use
it rather than the "state" field to hold Boolean flag values.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil<sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit 15d9882c336db2db73ccf9871ae2398e452f694c)
A ceph client has a pointer to a ceph messenger structure in it.
There is always exactly one ceph messenger for a ceph client, so
there is no need to allocate it separate from the ceph client
structure.
Switch the ceph_client structure to embed its ceph_messenger
structure.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit 6384bb8b8e88a9c6bf2ae0d9517c2c0199177c34)
No code sets a bad_proto method in its ceph connection operations
vector, so just get rid of it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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(cherry picked from commit e5e372da9a469dfe3ece40277090a7056c566838)
The ceph connection state "DEAD" is never set and is therefore not
needed. Eliminate it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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