The newly added support for the pcc mailbox fails to build
in some configurations:
drivers/i2c/busses/i2c-xgene-slimpro.c: In function 'xgene_slimpro_i2c_probe':
drivers/i2c/busses/i2c-xgene-slimpro.c:516:25: error: implicit declaration of function 'memremap'; did you mean 'memcmp'? [-Werror=implicit-function-declaration]
drivers/i2c/busses/i2c-xgene-slimpro.c:518:13: error: 'MEMREMAP_WB' undeclared (first use in this function)
drivers/i2c/busses/i2c-xgene-slimpro.c:518:13: note: each undeclared identifier is reported only once for each function it appears in
This includes the missing header file.
Fixes: df5da47fe7 ("i2c: xgene-slimpro: Add ACPI support by using PCC mailbox")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Hoan Tran <hotran@apm.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Lenovo Legion Y720-15IKBN is yet another Lenovo model that does not
have an hw rfkill switch, resulting in wifi always reported as hard
blocked.
Add the model to the list of models without rfkill switch.
Signed-off-by: Olle Liljenzin <olle@liljenzin.se>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Lenovo Legion Y520-15IKBN is yet another Lenovo model that does not
have an hw rfkill switch, resulting in wifi always reported as hard
blocked.
Add the model to the list of models without rfkill switch.
Signed-off-by: Olle Liljenzin <olle@liljenzin.se>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Pull x86 fixes from Thomas Gleixner:
"Two fixlets for x86:
- Handle WARN_ONs proper with the new UD based WARN implementation
- Disable 1G mappings when 2M mappings are disabled by kmemleak or
debug_pagealloc. Otherwise 1G mappings might still be used,
confusing the debug mechanisms"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Disable 1GB direct mappings when disabling 2MB mappings
x86/debug: Handle early WARN_ONs proper
Pull timer fixes from Thomas Gleixner:
"Three fixlets for timers:
- Two hot-fixes for the alarmtimer based posix timers, which prevent
a nasty DOS by self rescheduling timers. The proper cleanup of that
mess is queued for 4.13
- Make a function static"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick/broadcast: Make tick_broadcast_setup_oneshot() static
alarmtimer: Rate limit periodic intervals
alarmtimer: Prevent overflow of relative timers
Pull scheduler fixes from Thomas Gleixner:
"Two small fixes for the schedulre core:
- Use the proper switch_mm() variant in idle_task_exit() because that
code is not called with interrupts disabled.
- Fix a confusing typo in a printk"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Idle_task_exit() shouldn't use switch_mm_irqs_off()
sched/fair: Fix typo in printk message
Pull perf fixes from Thomas Gleixner:
"Three fixes for the perf user space side:
- Fix the probing of precise_ip level, which got broken recently for
x86.
- Unbreak the ARCH=x86_64 build
- Report module before trying to unwind into the module code, which
avoids broken stack frames displayed"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf unwind: Report module before querying isactivation in dwfl unwind
perf tools: Fix build with ARCH=x86_64
perf evsel: Fix probing of precise_ip level for default cycles event
Pull irq fix from Thomas Gleixner:
"Add a missing resource release to an error path"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Release resources in __setup_irq() error path
Pull objtool fix from Thomas Gleixner:
"A single fix which adds fortify_panic to the list of no return
functions"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Add fortify_panic as __noreturn function
After commit 6d3c8c0dd8 ("net: dsa: Remove master_netdev and
use dst->cpu_dp->netdev") and a29342e739 ("net: dsa: Associate
slave network device with CPU port") we would be seeing NULL pointer
dereferences when accessing dst->cpu_dp->netdev too early. In the legacy
code, we actually know early in advance the master network device, so
pass it down to the relevant functions.
Fixes: 6d3c8c0dd8 ("net: dsa: Remove master_netdev and use dst->cpu_dp->netdev")
Fixes: a29342e739 ("net: dsa: Associate slave network device with CPU port")
Reported-by: Jason Cobham <jcobham@questertangent.com>
Tested-by: Jason Cobham <jcobham@questertangent.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Missing crypto deps for some platforms.
Default to n for new module.
config: m68k-amcore_defconfig (attached as .config)
compiler: m68k-linux-gcc (GCC) 4.9.0
make.cross ARCH=m68k
All errors (new ones prefixed by >>):
net/built-in.o: In function `tls_set_sw_offload':
>> (.text+0x732f8): undefined reference to `crypto_alloc_aead'
net/built-in.o: In function `tls_set_sw_offload':
>> (.text+0x7333c): undefined reference to `crypto_aead_setkey'
net/built-in.o: In function `tls_set_sw_offload':
>> (.text+0x73354): undefined reference to `crypto_aead_setauthsize'
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Wei Wang says:
====================
remove dst garbage collector logic
The current mechanism of dst release is a bit complicated. It is because
the users of dst get divided into 2 situations:
1. Most users take the reference count when using a dst and release the
reference count when done.
2. Exceptional users like IPv4/IPv6/decnet/xfrm routing code do not take
reference count when referencing to a dst due to some histotic reasons.
Due to those exceptional use cases in 2, reference count being 0 is not an
adequate evidence to indicate that no user is using this dst. So users in 1
can't free the dst simply based on reference count being 0 because users in
2 might still hold reference to it.
Instead, a dst garbage list is needed to hold the dst entries that already
get removed by the users in 2 but are still held by users in 1. And a periodic
garbage collector task is run to check all the dst entries in the list to see
if the users in 1 have released the reference to those dst entries.
If so, the dst is now ready to be freed.
This logic introduces unnecessary complications in the dst code which makes it
hard to understand and to debug.
In order to get rid of the whole dst garbage collector (gc) and make the dst
code more unified and simplified, we can make the users in 2 also take reference
count on the dst and release it properly when done.
This way, dst can be safely freed once the refcount drops to 0 and no gc
thread is needed anymore.
This patch series' target is to completely get rid of dst gc logic and free
dst based on reference count only.
Patch 1-3 are preparation patches to do some cleanup/improvement on the existing
code to make later work easier.
Patch 4-21 are real implementations.
In these patches, a temporary flag DST_NOGC is used to help transition
those exceptional users one by one. Once every component is transitioned,
this temporary flag is removed.
By the end of this patch series, all dst are refcounted when being used
and released when done. And dst will be freed when its refcount drops to 0.
No dst gc task is running anymore.
Note: This patch series depends on the decnet fix that was sent right before:
"decnet: always not take dst->__refcnt when inserting dst into hash table"
v2:
add curly braces in udp_v4/6_early_demux() in patch 02
add EXPORT_SYMBOL() for dst_dev_put() in patch 05
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is meant to add a debug warning on the situation where dst is
being held during its destroy phase. This could potentially cause double
free issue on the dst.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As some dst flags are removed, reorder the dst flags to fill in the
blanks.
Note: these flags are not exposed into user space. So it is safe to
reorder.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
DST_NOCACHE flag check has been removed from dst_release() and
dst_hold_safe() in a previous patch because all the dst are now ref
counted properly and can be released based on refcnt only.
Looking at the rest of the DST_NOCACHE use, all of them can now be
removed or replaced with other checks.
So this patch gets rid of all the DST_NOCACHE usage and remove this flag
completely.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that all the components have been changed to release dst based on
refcnt only and not depend on dst gc anymore, we can remove the
temporary flag DST_NOGC.
Note that we also need to remove the DST_NOCACHE check in dst_release()
and dst_hold_safe() because now all the dst are released based on refcnt
and behaves as DST_NOCACHE.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes all dst gc related code and all the dst free
functions
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
struct dn_route is inserted into dn_rt_hash_table but no dst->__refcnt
is taken.
This patch makes sure the dn_rt_hash_table's reference to the dst is ref
counted.
As the dst is always ref counted properly, we can safely mark
DST_NOGC flag so dst_release() will release dst based on refcnt only.
And dst gc is no longer needed and all dst_free() or its related
function calls should be replaced with dst_release() or
dst_release_immediate(). And dst_dev_put() is called when removing dst
from the hash table to release the reference on dst->dev before we lose
pointer to it.
Also, correct the logic in dn_dst_check_expire() and dn_dst_gc() to
check dst->__refcnt to be > 1 to indicate it is referenced by other
users.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
During the creation of xfrm_dst bundle, always take ref count when
allocating the dst. This way, xfrm_bundle_create() will form a linked
list of dst with dst->child pointing to a ref counted dst child. And
the returned dst pointer is also ref counted. This makes the link from
the flow cache to this dst now ref counted properly.
As the dst is always ref counted properly, we can safely mark
DST_NOGC flag so dst_release() will release dst based on refcnt only.
And dst gc is no longer needed and all dst_free() and its related
function calls should be replaced with dst_release() or
dst_release_immediate().
The special handling logic for dst->child in dst_destroy() can be
replaced with a simple dst_release_immediate() call on the child to
release the whole list linked by dst->child pointer.
Previously used DST_NOHASH flag is not needed anymore as well. The
reason that DST_NOHASH is used in the existing code is mainly to prevent
the dst inserted in the fib tree to be wrongly destroyed during the
deletion of the xfrm_dst bundle. So in the existing code, DST_NOHASH
flag is marked in all the dst children except the one which is in the
fib tree.
However, with this patch series to remove dst gc logic and release dst
only based on ref count, it is safe to release all the children from a
xfrm_dst bundle as long as the dst children are all ref counted
properly which is already the case in the existing code.
So, this patch removes the use of DST_NOHASH flag.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
icmp6 dst route is currently ref counted during creation and will be
freed by user during its call of dst_release(). So no need of a garbage
collector for it.
Remove all icmp6 dst garbage collector related code.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With the previous preparation patches, we are ready to get rid of the
dst gc operation in ipv6 code and release dst based on refcnt only.
So this patch adds DST_NOGC flag for all IPv6 dst and remove the calls
to dst_free() and its related functions.
At this point, all dst created in ipv6 code do not use the dst gc
anymore and will be destroyed at the point when refcnt drops to 0.
Also, as icmp6 dst route is refcounted during creation and will be freed
by user during its call of dst_release(), there is no need to add this
dst to the icmp6 gc list as well.
Instead, we need to add it into uncached list so that when a
NETDEV_DOWN/NETDEV_UNREGISRER event comes, we can properly go through
these icmp6 dst as well and release the net device properly.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar as ipv4, ipv6 path also needs to call dst_hold_safe() when
necessary to avoid double free issue on the dst.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As the intend of this patch series is to completely remove dst gc,
we need to call dst_dev_put() to release the reference to dst->dev
when removing routes from fib because we won't keep the gc list anymore
and will lose the dst pointer right after removing the routes.
Without the gc list, there is no way to find all the dst's that have
dst->dev pointing to the going-down dev.
Hence, we are doing dst_dev_put() immediately before we lose the last
reference of the dst from the routing code. The next dst_check() will
trigger a route re-lookup to find another route (if there is any).
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In IPv6 routing code, struct rt6_info is created for each static route
and RTF_CACHE route and inserted into fib6 tree. In both cases, dst
ref count is not taken.
As explained in the previous patch, this leads to the need of the dst
garbage collector.
This patch holds ref count of dst before inserting the route into fib6
tree and properly releases the dst when deleting it from the fib6 tree
as a preparation in order to fully get rid of dst gc later.
Also, correct fib6_age() logic to check dst->__refcnt to be 1 to indicate
no user is referencing the dst.
And remove dst_hold() in vrf_rt6_create() as ip6_dst_alloc() already puts
dst->__refcnt to 1.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With the previous preparation patches, we are ready to get rid of the
dst gc operation in ipv4 code and release dst based on refcnt only.
So this patch adds DST_NOGC flag for all IPv4 dst and remove the calls
to dst_free().
At this point, all dst created in ipv4 code do not use the dst gc
anymore and will be destroyed at the point when refcnt drops to 0.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch checks all the calls to
dst_hold()/skb_dst_force()/dst_clone()/dst_use() to see if
dst_hold_safe() is needed to avoid double free issue if dst
gc is removed and dst_release() directly destroys dst when
dst->__refcnt drops to 0.
In tx path, TCP hold sk->sk_rx_dst ref count and also hold sock_lock().
UDP and other similar protocols always hold refcount for
skb->_skb_refdst. So both paths seem to be safe.
In rx path, as it is lockless and skb_dst_set_noref() is likely to be
used, dst_hold_safe() should always be used when trying to hold dst.
In the routing code, if dst is held during an rcu protected session, it
is necessary to call dst_hold_safe() as the current dst might be in its
rcu grace period.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As the intend of this patch series is to completely remove dst gc,
we need to call dst_dev_put() to release the reference to dst->dev
when removing routes from fib because we won't keep the gc list anymore
and will lose the dst pointer right after removing the routes.
Without the gc list, there is no way to find all the dst's that have
dst->dev pointing to the going-down dev.
Hence, we are doing dst_dev_put() immediately before we lose the last
reference of the dst from the routing code. The next dst_check() will
trigger a route re-lookup to find another route (if there is any).
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In IPv4 routing code, fib_nh and fib_nh_exception can hold pointers
to struct rtable but they never increment dst->__refcnt.
This leads to the need of the dst garbage collector because when user
is done with this dst and calls dst_release(), it can only decrement
dst->__refcnt and can not free the dst even it sees dst->__refcnt
drops from 1 to 0 (unless DST_NOCACHE flag is set) because the routing
code might still hold reference to it.
And when the routing code tries to delete a route, it has to put the
dst to the gc_list if dst->__refcnt is not yet 0 and have a gc thread
running periodically to check on dst->__refcnt and finally to free dst
when refcnt becomes 0.
This patch increments dst->__refcnt when
fib_nh/fib_nh_exception holds reference to this dst and properly release
the dst when fib_nh/fib_nh_exception has been updated with a new dst.
This patch is a preparation in order to fully get rid of dst gc later.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This function should be called when removing routes from fib tree after
the dst gc is no longer in use.
We first mark DST_OBSOLETE_DEAD on this dst to make sure next
dst_ops->check() fails and returns NULL.
Secondly, as we no longer keep the gc_list, we need to properly
release dst->dev right at the moment when the dst is removed from
the fib/fib6 tree.
It does the following:
1. change dst->input and output pointers to dst_discard/dst_dscard_out to
discard all packets
2. replace dst->dev with loopback interface
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current mechanism of freeing dst is a bit complicated. dst has its
ref count and when user grabs the reference to the dst, the ref count is
properly taken in most cases except in IPv4/IPv6/decnet/xfrm routing
code due to some historic reasons.
If the reference to dst is always taken properly, we should be able to
simplify the logic in dst_release() to destroy dst when dst->__refcnt
drops from 1 to 0. And this should be the only condition to determine
if we can call dst_destroy().
And as dst is always ref counted, there is no need for a dst garbage
list to hold the dst entries that already get removed by the routing
code but are still held by other users. And the task to periodically
check the list to free dst if ref count become 0 is also not needed
anymore.
This patch introduces a temporary flag DST_NOGC(no garbage collector).
If it is set in the dst, dst_release() will call dst_destroy() when
dst->__refcnt drops to 0. dst_hold_safe() will also check for this flag
and do atomic_inc_not_zero() similar as DST_NOCACHE to avoid double free
issue.
This temporary flag is mainly used so that we can make the transition
component by component without breaking other parts.
This flag will be removed after all components are properly transitioned.
This patch also introduces a new function dst_release_immediate() which
destroys dst without waiting on the rcu when refcnt drops to 0. It will
be used in later patches.
Follow-up patches will correct all the places to properly take ref count
on dst and mark DST_NOGC. dst_release() or dst_release_immediate() will
be used to release the dst instead of dst_free() and its related
functions.
And final clean-up patch will remove the DST_NOGC flag.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Existing ipv4/6_blackhole_route() code generates a blackhole route
with dst->dev pointing to the passed in dst->dev.
It is not necessary to hold reference to the passed in dst->dev
because the packets going through this route are dropped anyway.
A loopback interface is good enough so that we don't need to worry about
releasing this dst->dev when this dev is going down.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In udp_v4/6_early_demux() code, we try to hold dst->__refcnt for
dst with DST_NOCACHE flag. This is because later in udp_sk_rx_dst_set()
function, we will try to cache this dst in sk for connected case.
However, a better way to achieve this is to not try to hold dst in
early_demux(), but in udp_sk_rx_dst_set(), call dst_hold_safe(). This
approach is also more consistant with how tcp is handling it. And it
will make later changes simpler.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In ipv6 tx path, rcu_read_lock() is taken so that dst won't get freed
during the execution of ip6_fragment(). Hence, no need to hold dst in
it.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull LED fixes from Jacek Anaszewski:
"Two LED fixes:
- fix signal source assignment for leds-bcm6328
- revert patch that intended to fix LED behavior on suspend but it
had a side effect preventing suspend at all due to uevent being
sent on trigger removal"
* tag 'led_fixes_for_4.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
Revert "leds: handle suspend/resume in heartbeat trigger"
leds: bcm6328: fix signal source assignment for leds 4 to 7
Pull USB fixes from Greg KH:
"Here are some small gadget and xhci USB fixes for 4.12-rc6.
Nothing major, but one of the gadget patches does fix a reported oops,
and the xhci ones resolve reported problems. All have been in
linux-next with no reported issues"
* tag 'usb-4.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
USB: gadgetfs, dummy-hcd, net2280: fix locking for callbacks
usb: xhci: ASMedia ASM1042A chipset need shorts TX quirk
usb: xhci: Fix USB 3.1 supported protocol parsing
USB: gadget: fix GPF in gadgetfs
usb: gadget: composite: make sure to reactivate function on unbind
Pull staging and IIO fixes from Greg KH:
"Here are some small staging and IIO driver fixes for 4.12-rc6.
Nothing huge, just a few small driver fixes for reported issues. All
have been in linux-next with no reported issues"
* tag 'staging-4.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
Staging: rtl8723bs: fix an error code in isFileReadable()
iio: buffer-dmaengine: Add missing header buffer_impl.h
iio: buffer-dma: Add missing header buffer_impl.h
iio: adc: meson-saradc: fix potential crash in meson_sar_adc_clear_fifo
iio: adc: mxs-lradc: Fix return value check in mxs_lradc_adc_probe()
iio: imu: inv_mpu6050: add accel lpf setting for chip >= MPU6500
staging: iio: ad7152: Fix deadlock in ad7152_write_raw_samp_freq()
Select CONFIG_IMX7D_ADC so that the i.MX7 ADC driver can be
built by default.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Pull ceph fixes from Ilya Dryomov:
"A fix for an old ceph ->fh_to_* bug from Luis and two timestamp fixups
from Zheng, prompted by the ongoing y2038 work"
* tag 'ceph-for-4.12-rc6' of git://github.com/ceph/ceph-client:
ceph: unify inode i_ctime update
ceph: use current_kernel_time() to get request time stamp
ceph: check i_nlink while converting a file handle to dentry
* original hysteresis loop got broken by typo back in 2002; now
it never switches out of OPTTIME state. Fixed.
* critical levels for switching from OPTTIME to OPTSPACE and back
ought to be calculated once, at mount time.
* we should use mul_u64_u32_div() for those calculations, now that
->s_dsize is 64bit.
* to quote Kirk McKusick (in 1995 FreeBSD commit message):
The threshold for switching from time-space and space-time is too small
when minfree is 5%...so make it stay at space in this case.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Thomas Gleixner wrote:
> The CRIU support added a 'feature' which allows a user space task to send
> arbitrary (kernel) signals to itself. The changelog says:
>
> The kernel prevents sending of siginfo with positive si_code, because
> these codes are reserved for kernel. I think we can allow a task to
> send such a siginfo to itself. This operation should not be dangerous.
>
> Quite contrary to that claim, it turns out that it is outright dangerous
> for signals with info->si_code == SI_TIMER. The following code sequence in
> a user space task allows to crash the kernel:
>
> id = timer_create(CLOCK_XXX, ..... signo = SIGX);
> timer_set(id, ....);
> info->si_signo = SIGX;
> info->si_code = SI_TIMER:
> info->_sifields._timer._tid = id;
> info->_sifields._timer._sys_private = 2;
> rt_[tg]sigqueueinfo(..., SIGX, info);
> sigemptyset(&sigset);
> sigaddset(&sigset, SIGX);
> rt_sigtimedwait(sigset, info);
>
> For timers based on CLOCK_PROCESS_CPUTIME_ID, CLOCK_THREAD_CPUTIME_ID this
> results in a kernel crash because sigwait() dequeues the signal and the
> dequeue code observes:
>
> info->si_code == SI_TIMER && info->_sifields._timer._sys_private != 0
>
> which triggers the following callchain:
>
> do_schedule_next_timer() -> posix_cpu_timer_schedule() -> arm_timer()
>
> arm_timer() executes a list_add() on the timer, which is already armed via
> the timer_set() syscall. That's a double list add which corrupts the posix
> cpu timer list. As a consequence the kernel crashes on the next operation
> touching the posix cpu timer list.
>
> Posix clocks which are internally implemented based on hrtimers are not
> affected by this because hrtimer_start() can handle already armed timers
> nicely, but it's a reliable way to trigger the WARN_ON() in
> hrtimer_forward(), which complains about calling that function on an
> already armed timer.
This problem has existed since the posix timer code was merged into
2.5.63. A few releases earlier in 2.5.60 ptrace gained the ability to
inject not just a signal (which linux has supported since 1.0) but the
full siginfo of a signal.
The core problem is that the code will reschedule in response to
signals getting dequeued not just for signals the timers sent but
for other signals that happen to a si_code of SI_TIMER.
Avoid this confusion by testing to see if the queued signal was
preallocated as all timer signals are preallocated, and so far
only the timer code preallocates signals.
Move the check for if a timer needs to be rescheduled up into
collect_signal where the preallocation check must be performed,
and pass the result back to dequeue_signal where the code reschedules
timers. This makes it clear why the code cares about preallocated
timers.
Cc: stable@vger.kernel.org
Reported-by: Thomas Gleixner <tglx@linutronix.de>
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Reference: 66dd34ad31 ("signal: allow to send any siginfo to itself")
Reference: 1669ce53e2ff ("Add PTRACE_GETSIGINFO and PTRACE_SETSIGINFO")
Fixes: db8b50ba75f2 ("[PATCH] POSIX clocks & timers")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The cm-fx6 module has an on-board AW-NH387 WiFi/BT module which is
based on Marvell's SD8787 chip and is connected to the usdhc1
controller.
Unfortunately, the chip gets unresponsive if the Bluetooth AMP
(Alternate Mac/Phy) function gets probed but the loaded firmware
doesn't support it. For instance, this is the case for the most
recent firmware in linux-firmware (Version 14.66.35.p52).
Thus, just add the required nodes but leave the usdhc1 node disabled
explicitly. Users who disabled the Bluetooth (AMP) support of their
OS can then conveniently enable WiFi (or even plain Bluetooth) support
with a simple device tree overlay/bootloader configuration.
Signed-off-by: Christopher Spinrath <christopher.spinrath@rwth-aachen.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Currently the help text for the MXS_DMA option is incomplete as it does
not mention MX6SX, MX6ULL and MX7D, for example.
Instead of extending this list everytime a new SoC comes out, let's
keep the text more generic.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
The Actions Semi S500 is a quad-core ARM Cortex-A9 SoC.
The LeMaker Guitar is an SODIMM-format module with that SoC.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Buffer object specific resources like pages, domains, sg list
need not be protected with struct_mutex. They can be protected
with a buffer object level lock. This simplifies locking and
makes it easier to avoid potential recursive locking scenarios
for SVM involving mmap_sem and struct_mutex. This also removes
unnecessary serialization when creating buffer objects, and also
between buffer object creation and GPU command submission.
Signed-off-by: Sushmita Susheelendra <ssusheel@codeaurora.org>
[robclark: squash in handling new locking for shrinker]
Signed-off-by: Rob Clark <robdclark@gmail.com>
Pull xfs fix from Darrick Wong:
"One more bugfix for you for 4.12-rc6 to fix something that came up in
an earlier rc:
- Fix some bogus ASSERT failures on CONFIG_SMP=n and CONFIG_XFS_DEBUG=y"
* tag 'xfs-4.12-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: fix spurious spin_is_locked() assert failures on non-smp kernels
