MACs should, in general, be compared using crypto_memneq() to prevent
timing attacks.
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
The encrypted-keys module was using a single global HMAC transform,
which could be rekeyed by multiple threads concurrently operating on
different keys, causing incorrect HMAC values to be calculated. Fix
this by allocating a new HMAC transform whenever we need to calculate a
HMAC. Also simplify things a bit by allocating the shash_desc's using
SHASH_DESC_ON_STACK() for both the HMAC and unkeyed hashes.
The following script reproduces the bug:
keyctl new_session
keyctl add user master "abcdefghijklmnop" @s
for i in $(seq 2); do
(
set -e
for j in $(seq 1000); do
keyid=$(keyctl add encrypted desc$i "new user:master 25" @s)
datablob="$(keyctl pipe $keyid)"
keyctl unlink $keyid > /dev/null
keyid=$(keyctl add encrypted desc$i "load $datablob" @s)
keyctl unlink $keyid > /dev/null
done
) &
done
Output with bug:
[ 439.691094] encrypted_key: bad hmac (-22)
add_key: Invalid argument
add_key: Invalid argument
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
With the 'encrypted' key type it was possible for userspace to provide a
data blob ending with a master key description shorter than expected,
e.g. 'keyctl add encrypted desc "new x" @s'. When validating such a
master key description, validate_master_desc() could read beyond the end
of the buffer. Fix this by using strncmp() instead of memcmp(). [Also
clean up the code to deduplicate some logic.]
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Since v4.9, the crypto API cannot (normally) be used to encrypt/decrypt
stack buffers because the stack may be virtually mapped. Fix this for
the padding buffers in encrypted-keys by using ZERO_PAGE for the
encryption padding and by allocating a temporary heap buffer for the
decryption padding.
Tested with CONFIG_DEBUG_SG=y:
keyctl new_session
keyctl add user master "abcdefghijklmnop" @s
keyid=$(keyctl add encrypted desc "new user:master 25" @s)
datablob="$(keyctl pipe $keyid)"
keyctl unlink $keyid
keyid=$(keyctl add encrypted desc "load $datablob" @s)
datablob2="$(keyctl pipe $keyid)"
[ "$datablob" = "$datablob2" ] && echo "Success!"
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
In join_session_keyring(), if install_session_keyring_to_cred() were to
fail, we would leak the keyring reference, just like in the bug fixed by
commit 23567fd052 ("KEYS: Fix keyring ref leak in
join_session_keyring()"). Fortunately this cannot happen currently, but
we really should be more careful. Do this by adding and using a new
error label at which the keyring reference is dropped.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Omit an extra message for a memory allocation failure in this function.
This issue was detected by using the Coccinelle software.
Link: http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdf
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
We forgot to set the error code on this path so it could result in
returning NULL which leads to a NULL dereference.
Fixes: db6c43bd21 ("crypto: KEYS: convert public key and digsig asym to the akcipher api")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
With the new standardized functions, we can replace all ACCESS_ONCE()
calls across relevant security/keyrings/.
ACCESS_ONCE() does not work reliably on non-scalar types. For example
gcc 4.6 and 4.7 might remove the volatile tag for such accesses during
the SRA (scalar replacement of aggregates) step:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145
Update the new calls regardless of if it is a scalar type, this is
cleaner than having three alternatives.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
CONFIG_KEYS_COMPAT is defined in arch-specific Kconfigs and is missing for
several 64-bit architectures : mips, parisc, tile.
At the moment and for those architectures, calling in 32-bit userspace the
keyctl syscall would return an ENOSYS error.
This patch moves the CONFIG_KEYS_COMPAT option to security/keys/Kconfig, to
make sure the compatibility wrapper is registered by default for any 64-bit
architecture as long as it is configured with CONFIG_COMPAT.
[DH: Modified to remove arm64 compat enablement also as requested by Eric
Biggers]
Signed-off-by: Bilal Amarni <bilal.amarni@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
cc: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
A bunch of fixes for vmwgfx 4.12 regressions and older stuff. In the latter
case either trivial, cc'd stable or requiring backports for stable.
* 'vmwgfx-fixes-4.12' of git://people.freedesktop.org/~thomash/linux:
drm/vmwgfx: Bump driver minor and date
drm/vmwgfx: Remove unused legacy cursor functions
drm/vmwgfx: fix spelling mistake "exeeds" -> "exceeds"
drm/vmwgfx: Fix large topology crash
drm/vmwgfx: Make sure to update STDU when FB is updated
drm/vmwgfx: Make sure backup_handle is always valid
drm/vmwgfx: Handle vmalloc() failure in vmw_local_fifo_reserve()
drm/vmwgfx: Don't create proxy surface for cursor
drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()
drm/i915 fixes for v4.12-rc5
* tag 'drm-intel-fixes-2017-06-08' of git://anongit.freedesktop.org/git/drm-intel:
drm/i915: fix warning for unused variable
drm/i915: Fix 90/270 rotated coordinates for FBC
drm/i915: Restore has_fbc=1 for ILK-M
drm/i915: Workaround VLV/CHV DSI scanline counter hardware fail
drm/i915: Fix logical inversion for gen4 quirking
drm/i915: Guard against i915_ggtt_disable_guc() being invoked unconditionally
drm/i915: Always recompute watermarks when distrust_bios_wm is set, v2.
drm/i915: Prevent the system suspend complete optimization
drm/i915/psr: disable psr2 for resolution greater than 32X20
drm/i915: Hold a wakeref for probing the ring registers
drm/i915: Short-circuit i915_gem_wait_for_idle() if already idle
drm/i915: Disable decoupled MMIO
drm/i915/guc: Remove stale comment for q_fail
drm/i915: Serialize GTT/Aperture accesses on BXT
Driver Changes:
- kirin: Use correct dt port for the bridge (John)
- meson: Fix regression caused by adding HDMI support to allow board
configurations without HDMI (Neil)
Cc: John Stultz <john.stultz@linaro.org>
Cc: Neil Armstrong <narmstrong@baylibre.com>
* tag 'drm-misc-fixes-2017-06-07' of git://anongit.freedesktop.org/git/drm-misc:
drm/meson: Fix driver bind when only CVBS is available
drm: kirin: Fix drm_of_find_panel_or_bridge conversion
- Keep the external clock input to the PRE ungated and only use the internal
soft reset to keep the module in low power state, to avoid sporadic startup
failures.
- Ignore -ENODEV return values from drm_of_find_panel_or_bridge in the LDB
driver to fix probing for devices that still do not specify a panel in the
device tree.
- Fix the CSI input selection to the VDIC. According to experiments, the real
behaviour differs a bit from the documentation.
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Merge tag 'imx-drm-fixes-2017-06-08' of git://git.pengutronix.de/git/pza/linux into drm-fixes
imx-drm: PRE clock gating, panelless LDB, and VDIC CSI selection fixes
- Keep the external clock input to the PRE ungated and only use the internal
soft reset to keep the module in low power state, to avoid sporadic startup
failures.
- Ignore -ENODEV return values from drm_of_find_panel_or_bridge in the LDB
driver to fix probing for devices that still do not specify a panel in the
device tree.
- Fix the CSI input selection to the VDIC. According to experiments, the real
behaviour differs a bit from the documentation.
* tag 'imx-drm-fixes-2017-06-08' of git://git.pengutronix.de/git/pza/linux:
gpu: ipu-v3: Fix CSI selection for VDIC
drm/imx: imx-ldb: Accept drm_of_find_panel_or_bridge failure
gpu: ipu-v3: pre: only use internal clock gating
- Revert a recent commit that attempted to avoid spurious wakeups
from suspend-to-idle via ACPI SCI, but introduced regressions on
some systems (Rafael Wysocki).
We will get back to the problem it tried to address in the next
cycle.
- Fix a possible division by 0 during intel_pstate initialization
due to a missing check (Rafael Wysocki).
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Merge tag 'pm-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These revert one problematic commit related to system sleep and fix
one recent intel_pstate regression.
Specifics:
- Revert a recent commit that attempted to avoid spurious wakeups
from suspend-to-idle via ACPI SCI, but introduced regressions on
some systems (Rafael Wysocki).
We will get back to the problem it tried to address in the next
cycle.
- Fix a possible division by 0 during intel_pstate initialization
due to a missing check (Rafael Wysocki)"
* tag 'pm-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"
cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min()
The commit e7ee404757 ("perf symbols: Fix symbols searching for module
in buildid-cache") added the function to check kernel modules reside in
the build-id cache. This was because there's no way to identify a DSO
which is actually a kernel module. So it searched linkname of the file
and find ".ko" suffix.
But this does not work for compressed kernel modules and now such DSOs
hCcave correct symtab_type now. So no need to check it anymore. This
patch essentially reverts the commit.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-10-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The symsrc__init() overwrites dso->symtab_type as symsrc->type in
dso__load_sym(). But for compressed kernel modules in the build-id
cache, it should have original symtab type to be decompressed as needed.
This fixes perf annotate to show disassembly of the function properly.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-9-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If a kernel modules is compressed, it should be decompressed before
running objdump to parse binary data correctly. This fixes a failure of
object code reading test for me.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
On failure, it should free the 'name', so clean up the error path using
goto.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-7-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently perf decompresses kernel modules when loading the symbol table
but it missed to do it when reading raw data.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Convert open-coded decompress routine to use the function.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Move decompress_kmodule() to util/dso.c and split it into two functions
returning fd and (decompressed) file path. The existing user only wants
the fd version but the path version will be used soon.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The 'name' variable should be freed on the error path.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The commit 6ebd2547dd ("perf annotate: Fix a bug following symbolic
link of a build-id file") changed to use dirname to follow the symlink.
But it only considers new-style build-id cache names so old names fail
on readlink() and force to use system path which might not available.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Taeung Song <treeze.taeung@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-team@lge.com
Fixes: 6ebd2547dd ("perf annotate: Fix a bug following symbolic link of a build-id file")
Link: http://lkml.kernel.org/r/20170608073109.30699-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull printk fix from Petr Mladek:
"This reverts a fix added into 4.12-rc1. It caused the kernel log to be
printed on another console when two consoles of the same type were
defined, e.g. console=ttyS0 console=ttyS1.
This configuration was never supported by kernel itself, but it
started to make sense with systemd. In other words, the commit broke
userspace"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
Revert "printk: fix double printing with earlycon"
Pull crypto fixes from Herbert Xu:
"This fixes a couple of places in the crypto code that were doing
interruptible sleeps dangerously. They have been converted to use
non-interruptible sleeps.
This also fixes a bug in asymmetric_keys where it would trigger a
use-after-free if a request returned EBUSY due to a full device queue"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: gcm - wait for crypto op not signal safe
crypto: drbg - wait for crypto op not signal safe
crypto: asymmetric_keys - handle EBUSY due to backlog correctly
In blk-cgroup, operations on blkg objects are protected with the
request_queue lock. This is no more the lock that protects
I/O-scheduler operations in blk-mq. In fact, the latter are now
protected with a finer-grained per-scheduler-instance lock. As a
consequence, although blkg lookups are also rcu-protected, blk-mq I/O
schedulers may see inconsistent data when they access blkg and
blkg-related objects. BFQ does access these objects, and does incur
this problem, in the following case.
The blkg_lookup performed in bfq_get_queue, being protected (only)
through rcu, may happen to return the address of a copy of the
original blkg. If this is the case, then the blkg_get performed in
bfq_get_queue, to pin down the blkg, is useless: it does not prevent
blk-cgroup code from destroying both the original blkg and all objects
directly or indirectly referred by the copy of the blkg. BFQ accesses
these objects, which typically causes a crash for NULL-pointer
dereference of memory-protection violation.
Some additional protection mechanism should be added to blk-cgroup to
address this issue. In the meantime, this commit provides a quick
temporary fix for BFQ: cache (when safe) blkg data that might
disappear right after a blkg_lookup.
In particular, this commit exploits the following facts to achieve its
goal without introducing further locks. Destroy operations on a blkg
invoke, as a first step, hooks of the scheduler associated with the
blkg. And these hooks are executed with bfqd->lock held for BFQ. As a
consequence, for any blkg associated with the request queue an
instance of BFQ is attached to, we are guaranteed that such a blkg is
not destroyed, and that all the pointers it contains are consistent,
while that instance is holding its bfqd->lock. A blkg_lookup performed
with bfqd->lock held then returns a fully consistent blkg, which
remains consistent until this lock is held. In more detail, this holds
even if the returned blkg is a copy of the original one.
Finally, also the object describing a group inside BFQ needs to be
protected from destruction on the blkg_free of the original blkg
(which invokes bfq_pd_free). This commit adds private refcounting for
this object, to let it disappear only after no bfq_queue refers to it
any longer.
This commit also removes or updates some stale comments on locking
issues related to blk-cgroup operations.
Reported-by: Tomas Konir <tomas.konir@gmail.com>
Reported-by: Lee Tibbert <lee.tibbert@gmail.com>
Reported-by: Marco Piazza <mpiazza@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Tested-by: Tomas Konir <tomas.konir@gmail.com>
Tested-by: Lee Tibbert <lee.tibbert@gmail.com>
Tested-by: Marco Piazza <mpiazza@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Linu Cherian reported a WARN in cleanup_srcu_struct() when shutting
down a guest running iperf on a VFIO assigned device. This happens
because irqfd_wakeup() calls srcu_read_lock(&kvm->irq_srcu) in interrupt
context, while a worker thread does the same inside kvm_set_irq(). If the
interrupt happens while the worker thread is executing __srcu_read_lock(),
updates to the Classic SRCU ->lock_count[] field or the Tree SRCU
->srcu_lock_count[] field can be lost.
The docs say you are not supposed to call srcu_read_lock() and
srcu_read_unlock() from irq context, but KVM interrupt injection happens
from (host) interrupt context and it would be nice if SRCU supported the
use case. KVM is using SRCU here not really for the "sleepable" part,
but rather due to its IPI-free fast detection of grace periods. It is
therefore not desirable to switch back to RCU, which would effectively
revert commit 719d93cd5f ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING",
2014-01-16).
However, the docs are overly conservative. You can have an SRCU instance
only has users in irq context, and you can mix process and irq context
as long as process context users disable interrupts. In addition,
__srcu_read_unlock() actually uses this_cpu_dec() on both Tree SRCU and
Classic SRCU. For those two implementations, only srcu_read_lock()
is unsafe.
When Classic SRCU's __srcu_read_unlock() was changed to use this_cpu_dec(),
in commit 5a41344a3d ("srcu: Simplify __srcu_read_unlock() via
this_cpu_dec()", 2012-11-29), __srcu_read_lock() did two increments.
Therefore it kept __this_cpu_inc(), with preempt_disable/enable in
the caller. Tree SRCU however only does one increment, so on most
architectures it is more efficient for __srcu_read_lock() to use
this_cpu_inc(), and any performance differences appear to be down in
the noise.
Cc: stable@vger.kernel.org
Fixes: 719d93cd5f ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING")
Reported-by: Linu Cherian <linuc.decode@gmail.com>
Suggested-by: Linu Cherian <linuc.decode@gmail.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Linu Cherian reported a WARN in cleanup_srcu_struct() when shutting
down a guest running iperf on a VFIO assigned device. This happens
because irqfd_wakeup() calls srcu_read_lock(&kvm->irq_srcu) in interrupt
context, while a worker thread does the same inside kvm_set_irq(). If the
interrupt happens while the worker thread is executing __srcu_read_lock(),
updates to the Classic SRCU ->lock_count[] field or the Tree SRCU
->srcu_lock_count[] field can be lost.
The docs say you are not supposed to call srcu_read_lock() and
srcu_read_unlock() from irq context, but KVM interrupt injection happens
from (host) interrupt context and it would be nice if SRCU supported the
use case. KVM is using SRCU here not really for the "sleepable" part,
but rather due to its IPI-free fast detection of grace periods. It is
therefore not desirable to switch back to RCU, which would effectively
revert commit 719d93cd5f ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING",
2014-01-16).
However, the docs are overly conservative. You can have an SRCU instance
only has users in irq context, and you can mix process and irq context
as long as process context users disable interrupts. In addition,
__srcu_read_unlock() actually uses this_cpu_dec() on both Tree SRCU and
Classic SRCU. For those two implementations, only srcu_read_lock()
is unsafe.
When Classic SRCU's __srcu_read_unlock() was changed to use this_cpu_dec(),
in commit 5a41344a3d ("srcu: Simplify __srcu_read_unlock() via
this_cpu_dec()", 2012-11-29), __srcu_read_lock() did two increments.
Therefore it kept __this_cpu_inc(), with preempt_disable/enable in
the caller. Tree SRCU however only does one increment, so on most
architectures it is more efficient for __srcu_read_lock() to use
this_cpu_inc(), and any performance differences appear to be down in
the noise.
Unlike Classic and Tree SRCU, Tiny SRCU does increments and decrements on
a single variable. Therefore, as Peter Zijlstra pointed out, Tiny SRCU's
implementation already supports mixed-context use of srcu_read_lock()
and srcu_read_unlock(), at least as long as uses of srcu_read_lock()
and srcu_read_unlock() in each handler are nested and paired properly.
In other words, it is still illegal to (say) invoke srcu_read_lock()
in an interrupt handler and to invoke the matching srcu_read_unlock()
in a softirq handler. Therefore, the only change required for Tiny SRCU
is to its comments.
Fixes: 719d93cd5f ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING")
Reported-by: Linu Cherian <linuc.decode@gmail.com>
Suggested-by: Linu Cherian <linuc.decode@gmail.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Paolo Bonzini <pbonzini@redhat.com>
When generating bootable VM images certain systems (most notably
s390x) require devices with 4k blocksize. This patch implements
a new flag 'LO_FLAGS_BLOCKSIZE' which will set the physical
blocksize to that of the underlying device, and allow to change
the logical blocksize for up to the physical blocksize.
Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
- The newly created AIS capability enables the feature unconditionally
and ignores the cpu model
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Merge tag 'kvm-s390-master-4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
KVM: s390: Fix for master (4.12)
- The newly created AIS capability enables the feature unconditionally
and ignores the cpu model
Christoph writes:
"A few NVMe fixes for 4.12-rc, PCIe reset fixes and APST fixes, a
RDMA reconnect fix, two FC fixes and a general controller removal fix."
drivers/gpu/drm/i915/intel_engine_cs.c: In function ‘intel_engine_is_idle’:
drivers/gpu/drm/i915/intel_engine_cs.c:1103:27: error: unused variable ‘dev_priv’ [-Werror=unused-variable]
struct drm_i915_private *dev_priv = engine->i915;
^~~~~~~~
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
While installing SLES-12 (based on v4.4), I found that the installer
will stall for 60+ seconds during LVM disk scan. The root cause was
determined to be the removal of a bound device check in loop_flush()
by commit b5dd2f6047 ("block: loop: improve performance via blk-mq").
Restoring this check, examining ->lo_state as set by loop_set_fd()
eliminates the bad behavior.
Test method:
modprobe loop max_loop=64
dd if=/dev/zero of=disk bs=512 count=200K
for((i=0;i<4;i++))do losetup -f disk; done
mkfs.ext4 -F /dev/loop0
for((i=0;i<4;i++))do mkdir t$i; mount /dev/loop$i t$i;done
for f in `ls /dev/loop[0-9]*|sort`; do \
echo $f; dd if=$f of=/dev/null bs=512 count=1; \
done
Test output: stock patched
/dev/loop0 18.1217e-05 8.3842e-05
/dev/loop1 6.1114e-05 0.000147979
/dev/loop10 0.414701 0.000116564
/dev/loop11 0.7474 6.7942e-05
/dev/loop12 0.747986 8.9082e-05
/dev/loop13 0.746532 7.4799e-05
/dev/loop14 0.480041 9.3926e-05
/dev/loop15 1.26453 7.2522e-05
Note that from loop10 onward, the device is not mounted, yet the
stock kernel consumes several orders of magnitude more wall time
than it does for a mounted device.
(Thanks for Mike Galbraith <efault@gmx.de>, give a changelog review.)
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: James Wang <jnwang@suse.com>
Fixes: b5dd2f6047 ("block: loop: improve performance via blk-mq")
Signed-off-by: Jens Axboe <axboe@fb.com>
If "i" is the last element in the vcpu->arch.cpuid_entries[] array, it
potentially can be exploited the vulnerability. this will out-of-bounds
read and write. Luckily, the effect is small:
/* when no next entry is found, the current entry[i] is reselected */
for (j = i + 1; ; j = (j + 1) % nent) {
struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j];
if (ej->function == e->function) {
It reads ej->maxphyaddr, which is user controlled. However...
ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
After cpuid_entries there is
int maxphyaddr;
struct x86_emulate_ctxt emulate_ctxt; /* 16-byte aligned */
So we have:
- cpuid_entries at offset 1B50 (6992)
- maxphyaddr at offset 27D0 (6992 + 3200 = 10192)
- padding at 27D4...27DF
- emulate_ctxt at 27E0
And it writes in the padding. Pfew, writing the ops field of emulate_ctxt
would have been much worse.
This patch fixes it by modding the index to avoid the out-of-bounds
access. Worst case, i == j and ej->function == e->function,
the loop can bail out.
Reported-by: Moguofang <moguofang@huawei.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Guofang Mo <moguofang@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Changes include:
- Fix an issue with migrating GICv2 VMs on GICv3 systems.
- Squashed a bug for gicv3 when figuring out preemption levels.
- Fix a potential null pointer derefence in KVM happening under memory
pressure.
- Maintain RES1 bits in the SCTLR_EL2 to make sure KVM works on new
architecture revisions.
- Allow unaligned accesses at EL2/HYP
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Merge tag 'kvm-arm-for-v4.12-rc5-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/ARM Fixes for v4.12-rc5 - Take 2
Changes include:
- Fix an issue with migrating GICv2 VMs on GICv3 systems.
- Squashed a bug for gicv3 when figuring out preemption levels.
- Fix a potential null pointer derefence in KVM happening under memory
pressure.
- Maintain RES1 bits in the SCTLR_EL2 to make sure KVM works on new
architecture revisions.
- Allow unaligned accesses at EL2/HYP
The PPC_DT_CPU_FTRs is a bit misplaced in menuconfig, it shows up with
other general kernel options. It's really more at home in the "Platform
Support" section, so move it there.
Also enable it by default, for Book3s 64. It does mostly nothing unless
the device tree properties are found, and we will want it enabled
eventually in distro kernels, so turn it on to start getting more
testing.
Fixes: 5a61ef74f2 ("powerpc/64s: Support new device tree binding for discovering CPU features")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Supporting 512TB requires us to do a order 3 allocation for level 1 page
table (pgd). This results in page allocation failures with certain workloads.
For now limit 4k linux page size config to 64TB.
Fixes: f6eedbba7a ("powerpc/mm/hash: Increase VA range to 128TB")
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fix error path if we can't copy user structure on CXL_IOCTL_START_WORK
ioctl. We shouldn't unlock the context status mutex as it was not
locked (yet).
Fixes: 0712dc7e73 ("cxl: Fix issues when unmapping contexts")
Cc: stable@vger.kernel.org # v3.19+
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This reverts commit cf39bf58af.
The commit regression to users that define both console=ttyS1
and console=ttyS0 on the command line, see
https://lkml.kernel.org/r/20170509082915.GA13236@bistromath.localdomain
The kernel log messages always appeared only on one serial port. It is
even documented in Documentation/admin-guide/serial-console.rst:
"Note that you can only define one console per device type (serial,
video)."
The above mentioned commit changed the order in which the command line
parameters are searched. As a result, the kernel log messages go to
the last mentioned ttyS* instead of the first one.
We long thought that using two console=ttyS* on the command line
did not make sense. But then we realized that console= parameters
were handled also by systemd, see
http://0pointer.de/blog/projects/serial-console.html
"By default systemd will instantiate one serial-getty@.service on
the main kernel console, if it is not a virtual terminal."
where
"[4] If multiple kernel consoles are used simultaneously, the main
console is the one listed first in /sys/class/tty/console/active,
which is the last one listed on the kernel command line."
This puts the original report into another light. The system is running
in qemu. The first serial port is used to store the messages into a file.
The second one is used to login to the system via a socket. It depends
on systemd and the historic kernel behavior.
By other words, systemd causes that it makes sense to define both
console=ttyS1 console=ttyS0 on the command line. The kernel fix
caused regression related to userspace (systemd) and need to be
reverted.
In addition, it went out that the fix helped only partially.
The messages still were duplicated when the boot console was
removed early by late_initcall(printk_late_init). Then the entire
log was replayed when the same console was registered as a normal one.
Link: 20170606160339.GC7604@pathway.suse.cz
Cc: Aleksey Makarov <aleksey.makarov@linaro.org>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Robin Murphy <robin.murphy@arm.com>,
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "Nair, Jayachandran" <Jayachandran.Nair@cavium.com>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
During early boot, load_ucode_intel_ap() uses __load_ucode_intel()
to obtain a pointer to the relevant microcode patch (embedded in the
initrd), and stores this value in 'intel_ucode_patch' to speed up the
microcode patch application for subsequent CPUs.
On resuming from suspend-to-RAM, however, load_ucode_ap() calls
load_ucode_intel_ap() for each non-boot-CPU. By then the initramfs is
long gone so the pointer stored in 'intel_ucode_patch' no longer points to
a valid microcode patch.
Clear that pointer so that we effectively fall back to the CPU hotplug
notifier callbacks to update the microcode.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
[ Edit and massage commit message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 4.10..
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170607095819.9754-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
I will be traveling in the upcoming months and it'll be much easier for me
to access my kernel.org email rather than my work one. Change my email
address in the MAINTAINERS file from jeyu@redhat.com to jeyu@kernel.org.
Signed-off-by: Jessica Yu <jeyu@redhat.com>
Without this the build will fail for !CONFIG_ACPI builds on x86.
Fixes: 94116f81 ("ACPI: Switch to use generic guid_t in acpi_evaluate_dsm()")
Signed-off-by: Christoph Hellwig <hch@lst.de>
It's possible that get_random_{u32,u64} is used before the crng has
initialized, in which case, its output might not be cryptographically
secure. For this problem, directly, this patch set is introducing the
*_wait variety of functions, but even with that, there's a subtle issue:
what happens to our batched entropy that was generated before
initialization. Prior to this commit, it'd stick around, supplying bad
numbers. After this commit, we force the entropy to be re-extracted
after each phase of the crng has initialized.
In order to avoid a race condition with the position counter, we
introduce a simple rwlock for this invalidation. Since it's only during
this awkward transition period, after things are all set up, we stop
using it, so that it doesn't have an impact on performance.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org # v4.11+
