Daniel Cashman [Thu, 14 Jan 2016 23:20:06 +0000 (15:20 -0800)]
x86: mm: support ARCH_MMAP_RND_BITS
x86: arch_mmap_rnd() uses hard-coded values, 8 for 32-bit and 28 for
64-bit, to generate the random offset for the mmap base address. This
value represents a compromise between increased ASLR effectiveness and
avoiding address-space fragmentation. Replace it with a Kconfig option,
which is sensibly bounded, so that platform developers may choose where
to place this compromise. Keep default values as new minimums.
Daniel Cashman [Thu, 14 Jan 2016 23:20:01 +0000 (15:20 -0800)]
arm64: mm: support ARCH_MMAP_RND_BITS
arm64: arch_mmap_rnd() uses STACK_RND_MASK to generate the random offset
for the mmap base address. This value represents a compromise between
increased ASLR effectiveness and avoiding address-space fragmentation.
Replace it with a Kconfig option, which is sensibly bounded, so that
platform developers may choose where to place this compromise. Keep
default values as new minimums.
Daniel Cashman [Thu, 14 Jan 2016 23:19:57 +0000 (15:19 -0800)]
arm: mm: support ARCH_MMAP_RND_BITS
arm: arch_mmap_rnd() uses a hard-code value of 8 to generate the random
offset for the mmap base address. This value represents a compromise
between increased ASLR effectiveness and avoiding address-space
fragmentation. Replace it with a Kconfig option, which is sensibly
bounded, so that platform developers may choose where to place this
compromise. Keep 8 as the minimum acceptable value.
Daniel Cashman [Thu, 14 Jan 2016 23:19:53 +0000 (15:19 -0800)]
mm: mmap: add new /proc tunable for mmap_base ASLR
Address Space Layout Randomization (ASLR) provides a barrier to
exploitation of user-space processes in the presence of security
vulnerabilities by making it more difficult to find desired code/data
which could help an attack. This is done by adding a random offset to
the location of regions in the process address space, with a greater
range of potential offset values corresponding to better protection/a
larger search-space for brute force, but also to greater potential for
fragmentation.
The offset added to the mmap_base address, which provides the basis for
the majority of the mappings for a process, is set once on process exec
in arch_pick_mmap_layout() and is done via hard-coded per-arch values,
which reflect, hopefully, the best compromise for all systems. The
trade-off between increased entropy in the offset value generation and
the corresponding increased variability in address space fragmentation
is not absolute, however, and some platforms may tolerate higher amounts
of entropy. This patch introduces both new Kconfig values and a sysctl
interface which may be used to change the amount of entropy used for
offset generation on a system.
The direct motivation for this change was in response to the
libstagefright vulnerabilities that affected Android, specifically to
information provided by Google's project zero at:
The attack presented therein, by Google's project zero, specifically
targeted the limited randomness used to generate the offset added to the
mmap_base address in order to craft a brute-force-based attack.
Concretely, the attack was against the mediaserver process, which was
limited to respawning every 5 seconds, on an arm device. The hard-coded
8 bits used resulted in an average expected success rate of defeating
the mmap ASLR after just over 10 minutes (128 tries at 5 seconds a
piece). With this patch, and an accompanying increase in the entropy
value to 16 bits, the same attack would take an average expected time of
over 45 hours (32768 tries), which makes it both less feasible and more
likely to be noticed.
The introduced Kconfig and sysctl options are limited by per-arch
minimum and maximum values, the minimum of which was chosen to match the
current hard-coded value and the maximum of which was chosen so as to
give the greatest flexibility without generating an invalid mmap_base
address, generally a 3-4 bits less than the number of bits in the
user-space accessible virtual address space.
When decided whether or not to change the default value, a system
developer should consider that mmap_base address could be placed
anywhere up to 2^(value) bits away from the non-randomized location,
which would introduce variable-sized areas above and below the mmap_base
address such that the maximum vm_area_struct size may be reduced,
preventing very large allocations.
This patch (of 4):
ASLR only uses as few as 8 bits to generate the random offset for the
mmap base address on 32 bit architectures. This value was chosen to
prevent a poorly chosen value from dividing the address space in such a
way as to prevent large allocations. This may not be an issue on all
platforms. Allow the specification of a minimum number of bits so that
platforms desiring greater ASLR protection may determine where to place
the trade-off.
mm/mmap.c: remove incorrect MAP_FIXED flag comparison from mmap_region
The following flag comparison in mmap_region makes no sense:
if (!(vm_flags & MAP_FIXED))
return -ENOMEM;
The condition is always false and thus the above "return -ENOMEM" is
never executed. The vm_flags must not be compared with MAP_FIXED flag.
The vm_flags may only be compared with VM_* flags. MAP_FIXED has the
same value as VM_MAYREAD.
Hitting the rlimit is a slow path and find_vma_intersection should
realize that there is no overlapping VMA for !MAP_FIXED case pretty
quickly.
Michal Hocko [Thu, 14 Jan 2016 23:19:47 +0000 (15:19 -0800)]
mm, vmscan: consider isolated pages in zone_reclaimable_pages
zone_reclaimable_pages counts how many pages are reclaimable in the
given zone. This currently includes all pages on file lrus and anon
lrus if there is an available swap storage. We do not consider
NR_ISOLATED_{ANON,FILE} counters though which is not correct because
these counters reflect temporarily isolated pages which are still
reclaimable because they either get back to their LRU or get freed
either by the page reclaim or page migration.
The number of these pages might be sufficiently high to confuse users of
zone_reclaimable_pages (e.g. mbind can migrate large ranges of memory
at once).
Vladimir Davydov [Thu, 14 Jan 2016 23:19:41 +0000 (15:19 -0800)]
memcg: do not allow to disable tcp accounting after limit is set
There are two bits defined for cg_proto->flags - MEMCG_SOCK_ACTIVATED
and MEMCG_SOCK_ACTIVE - both are set in tcp_update_limit, but the former
is never cleared while the latter can be cleared by unsetting the limit.
This allows to disable tcp socket accounting for new sockets after it
was enabled by writing -1 to memory.kmem.tcp.limit_in_bytes while still
guaranteeing that memcg_socket_limit_enabled static key will be
decremented on memcg destruction.
This functionality looks dubious, because it is not clear what a use
case would be. By enabling tcp accounting a user accepts the price. If
they then find the performance degradation unacceptable, they can always
restart their workload with tcp accounting disabled. It does not seem
there is any need to flip it while the workload is running.
Besides, it contradicts to how kmem accounting API works: writing
whatever to memory.kmem.limit_in_bytes enables kmem accounting for the
cgroup in question, after which it cannot be disabled. Therefore one
might expect that writing -1 to memory.kmem.tcp.limit_in_bytes just
enables socket accounting w/o limiting it, which might be useful by
itself, but it isn't true.
Since this API peculiarity is not documented anywhere, I propose to drop
it. This will allow to simplify the code by dropping cg_proto->flags.
Vladimir Davydov [Thu, 14 Jan 2016 23:19:38 +0000 (15:19 -0800)]
vmscan: do not force-scan file lru if its absolute size is small
We assume there is enough inactive page cache if the size of inactive
file lru is greater than the size of active file lru, in which case we
force-scan file lru ignoring anonymous pages. While this logic works
fine when there are plenty of page cache pages, it fails if the size of
file lru is small (several MB): in this case (lru_size >> prio) will be
0 for normal scan priorities, as a result, if inactive file lru happens
to be larger than active file lru, anonymous pages of a cgroup will
never get evicted unless the system experiences severe memory pressure,
even if there are gigabytes of unused anonymous memory there, which is
unfair in respect to other cgroups, whose workloads might be page cache
oriented.
This patch attempts to fix this by elaborating the "enough inactive page
cache" check: it makes it not only check that inactive lru size > active
lru size, but also that we will scan something from the cgroup at the
current scan priority. If these conditions do not hold, we proceed to
SCAN_FRACT as usual.
Jerome Marchand [Thu, 14 Jan 2016 23:19:29 +0000 (15:19 -0800)]
mm, procfs: breakdown RSS for anon, shmem and file in /proc/pid/status
There are several shortcomings with the accounting of shared memory
(SysV shm, shared anonymous mapping, mapping of a tmpfs file). The
values in /proc/<pid>/status and <...>/statm don't allow to distinguish
between shmem memory and a shared mapping to a regular file, even though
theirs implication on memory usage are quite different: during reclaim,
file mapping can be dropped or written back on disk, while shmem needs a
place in swap.
Also, to distinguish the memory occupied by anonymous and file mappings,
one has to read the /proc/pid/statm file, which has a field for the file
mappings (again, including shmem) and total memory occupied by these
mappings (i.e. equivalent to VmRSS in the <...>/status file. Getting
the value for anonymous mappings only is thus not exactly user-friendly
(the statm file is intended to be rather efficiently machine-readable).
To address both of these shortcomings, this patch adds a breakdown of
VmRSS in /proc/<pid>/status via new fields RssAnon, RssFile and
RssShmem, making use of the previous preparatory patch. These fields
tell the user the memory occupied by private anonymous pages, mapped
regular files and shmem, respectively. Other existing fields in /status
and /statm files are left without change. The /statm file can be
extended in the future, if there's a need for that.
Example (part of) /proc/pid/status output including the new Rss* fields:
Jerome Marchand [Thu, 14 Jan 2016 23:19:26 +0000 (15:19 -0800)]
mm, shmem: add internal shmem resident memory accounting
Currently looking at /proc/<pid>/status or statm, there is no way to
distinguish shmem pages from pages mapped to a regular file (shmem pages
are mapped to /dev/zero), even though their implication in actual memory
use is quite different.
The internal accounting currently counts shmem pages together with
regular files. As a preparation to extend the userspace interfaces,
this patch adds MM_SHMEMPAGES counter to mm_rss_stat to account for
shmem pages separately from MM_FILEPAGES. The next patch will expose it
to userspace - this patch doesn't change the exported values yet, by
adding up MM_SHMEMPAGES to MM_FILEPAGES at places where MM_FILEPAGES was
used before. The only user-visible change after this patch is the OOM
killer message that separates the reported "shmem-rss" from "file-rss".
Vlastimil Babka [Thu, 14 Jan 2016 23:19:23 +0000 (15:19 -0800)]
mm, proc: reduce cost of /proc/pid/smaps for unpopulated shmem mappings
Following the previous patch, further reduction of /proc/pid/smaps cost
is possible for private writable shmem mappings with unpopulated areas
where the page walk invokes the .pte_hole function. We can use radix
tree iterator for each such area instead of calling find_get_entry() in
a loop. This is possible at the extra maintenance cost of introducing
another shmem function shmem_partial_swap_usage().
To demonstrate the diference, I have measured this on a process that
creates a private writable 2GB mapping of a partially swapped out
/dev/shm/file (which cannot employ the optimizations from the prvious
patch) and doesn't populate it at all. I time how long does it take to
cat /proc/pid/smaps of this process 100 times.
Before this patch:
real 0m3.831s
user 0m0.180s
sys 0m3.212s
After this patch:
real 0m1.176s
user 0m0.180s
sys 0m0.684s
The time is similar to the case where a radix tree iterator is employed
on the whole mapping.
Vlastimil Babka [Thu, 14 Jan 2016 23:19:20 +0000 (15:19 -0800)]
mm, proc: reduce cost of /proc/pid/smaps for shmem mappings
The previous patch has improved swap accounting for shmem mapping, which
however made /proc/pid/smaps more expensive for shmem mappings, as we
consult the radix tree for each pte_none entry, so the overal complexity
is O(n*log(n)).
We can reduce this significantly for mappings that cannot contain COWed
pages, because then we can either use the statistics tha shmem object
itself tracks (if the mapping contains the whole object, or the swap
usage of the whole object is zero), or use the radix tree iterator,
which is much more effective than repeated find_get_entry() calls.
This patch therefore introduces a function shmem_swap_usage(vma) and
makes /proc/pid/smaps use it when possible. Only for writable private
mappings of shmem objects (i.e. tmpfs files) with the shmem object
itself (partially) swapped outwe have to resort to the find_get_entry()
approach.
Hopefully such mappings are relatively uncommon.
To demonstrate the diference, I have measured this on a process that
creates a 2GB mapping and dirties single pages with a stride of 2MB, and
time how long does it take to cat /proc/pid/smaps of this process 100
times.
Private writable mapping of a /dev/shm/file (the most complex case):
real 0m3.831s
user 0m0.180s
sys 0m3.212s
Shared mapping of an almost full mapping of a partially swapped /dev/shm/file
(which needs to employ the radix tree iterator).
real 0m1.351s
user 0m0.096s
sys 0m0.768s
Same, but with /dev/shm/file not swapped (so no radix tree walk needed)
real 0m0.935s
user 0m0.128s
sys 0m0.344s
Private anonymous mapping:
real 0m0.949s
user 0m0.116s
sys 0m0.348s
The cost is now much closer to the private anonymous mapping case, unless
the shmem mapping is private and writable.
Vlastimil Babka [Thu, 14 Jan 2016 23:19:17 +0000 (15:19 -0800)]
mm, proc: account for shmem swap in /proc/pid/smaps
Currently, /proc/pid/smaps will always show "Swap: 0 kB" for
shmem-backed mappings, even if the mapped portion does contain pages
that were swapped out. This is because unlike private anonymous
mappings, shmem does not change pte to swap entry, but pte_none when
swapping the page out. In the smaps page walk, such page thus looks
like it was never faulted in.
This patch changes smaps_pte_entry() to determine the swap status for
such pte_none entries for shmem mappings, similarly to how
mincore_page() does it. Swapped out shmem pages are thus accounted for.
For private mappings of tmpfs files that COWed some of the pages, swaped
out status of the original shmem pages is naturally ignored. If some of
the private copies was also swapped out, they are accounted via their
page table swap entries, so the resulting reported swap usage is then a
sum of both swapped out private copies, and swapped out shmem pages that
were not COWed. No double accounting can thus happen.
The accounting is arguably still not as precise as for private anonymous
mappings, since now we will count also pages that the process in
question never accessed, but another process populated them and then let
them become swapped out. I believe it is still less confusing and
subtle than not showing any swap usage by shmem mappings at all.
Swapped out counter might of interest of users who would like to prevent
from future swapins during performance critical operation and pre-fault
them at their convenience. Especially for larger swapped out regions
the cost of swapin is much higher than a fresh page allocation. So a
differentiation between pte_none vs. swapped out is important for those
usecases.
One downside of this patch is that it makes /proc/pid/smaps more
expensive for shmem mappings, as we consult the radix tree for each
pte_none entry, so the overal complexity is O(n*log(n)). I have
measured this on a process that creates a 2GB mapping and dirties single
pages with a stride of 2MB, and time how long does it take to cat
/proc/pid/smaps of this process 100 times.
Private anonymous mapping:
real 0m0.949s
user 0m0.116s
sys 0m0.348s
Mapping of a /dev/shm/file:
real 0m3.831s
user 0m0.180s
sys 0m3.212s
The difference is rather substantial, so the next patch will reduce the
cost for shared or read-only mappings.
In a less controlled experiment, I've gathered pids of processes on my
desktop that have either '/dev/shm/*' or 'SYSV*' in smaps. This
included the Chrome browser and some KDE processes. Again, I've run cat
/proc/pid/smaps on each 100 times.
Before this patch:
real 0m9.050s
user 0m0.518s
sys 0m8.066s
After this patch:
real 0m9.221s
user 0m0.541s
sys 0m8.187s
This suggests low impact on average systems.
Note that this patch doesn't attempt to adjust the SwapPss field for
shmem mappings, which would need extra work to determine who else could
have the pages mapped. Thus the value stays zero except for COWed
swapped out pages in a shmem mapping, which are accounted as usual.
Vlastimil Babka [Thu, 14 Jan 2016 23:19:14 +0000 (15:19 -0800)]
mm, documentation: clarify /proc/pid/status VmSwap limitations for shmem
This series is based on Jerome Marchand's [1] so let me quote the first
paragraph from there:
There are several shortcomings with the accounting of shared memory
(sysV shm, shared anonymous mapping, mapping to a tmpfs file). The
values in /proc/<pid>/status and statm don't allow to distinguish
between shmem memory and a shared mapping to a regular file, even though
their implications on memory usage are quite different: at reclaim, file
mapping can be dropped or written back on disk while shmem needs a place
in swap. As for shmem pages that are swapped-out or in swap cache, they
aren't accounted at all.
The original motivation for myself is that a customer found (IMHO
rightfully) confusing that e.g. top output for process swap usage is
unreliable with respect to swapped out shmem pages, which are not
accounted for.
The fundamental difference between private anonymous and shmem pages is
that the latter has PTE's converted to pte_none, and not swapents. As
such, they are not accounted to the number of swapents visible e.g. in
/proc/pid/status VmSwap row. It might be theoretically possible to use
swapents when swapping out shmem (without extra cost, as one has to
change all mappers anyway), and on swap in only convert the swapent for
the faulting process, leaving swapents in other processes until they
also fault (so again no extra cost). But I don't know how many
assumptions this would break, and it would be too disruptive change for
a relatively small benefit.
Instead, my approach is to document the limitation of VmSwap, and
provide means to determine the swap usage for shmem areas for those who
are interested and willing to pay the price, using /proc/pid/smaps.
Because outside of ipcs, I don't think it's possible to currently to
determine the usage at all. The previous patchset [1] did introduce new
shmem-specific fields into smaps output, and functions to determine the
values. I take a simpler approach, noting that smaps output already has
a "Swap: X kB" line, where currently X == 0 always for shmem areas. I
think we can just consider this a bug and provide the proper value by
consulting the radix tree, as e.g. mincore_page() does. In the patch
changelog I explain why this is also not perfect (and cannot be without
swapents), but still arguably much better than showing a 0.
The last two patches are adapted from Jerome's patchset and provide a
VmRSS breakdown to RssAnon, RssFile and RssShm in /proc/pid/status.
Hugh noted that this is a welcome addition, and I agree that it might
help e.g. debugging process memory usage at albeit non-zero, but still
rather low cost of extra per-mm counter and some page flag checks.
[1] http://lwn.net/Articles/611966/
This patch (of 6):
The documentation for /proc/pid/status does not mention that the value
of VmSwap counts only swapped out anonymous private pages, and not
swapped out pages of the underlying shmem objects (for shmem mappings).
This is not obvious, so document this limitation.
Michal Hocko [Thu, 14 Jan 2016 23:19:05 +0000 (15:19 -0800)]
mm/page_alloc.c: do not loop over ALLOC_NO_WATERMARKS without triggering reclaim
__alloc_pages_slowpath is looping over ALLOC_NO_WATERMARKS requests if
__GFP_NOFAIL is requested. This is fragile because we are basically
relying on somebody else to make the reclaim (be it the direct reclaim
or OOM killer) for us. The caller might be holding resources (e.g.
locks) which block other other reclaimers from making any progress for
example. Remove the retry loop and rely on __alloc_pages_slowpath to
invoke all allowed reclaim steps and retry logic.
We have to be careful about __GFP_NOFAIL allocations from the
PF_MEMALLOC context even though this is a very bad idea to begin with
because no progress can be gurateed at all. We shouldn't break the
__GFP_NOFAIL semantic here though. It could be argued that this is
essentially GFP_NOWAIT context which we do not support but PF_MEMALLOC
is much harder to check for existing users because they might happen
deep down the code path performed much later after setting the flag so
we cannot really rule out there is no kernel path triggering this
combination.
Michal Hocko [Thu, 14 Jan 2016 23:19:03 +0000 (15:19 -0800)]
mm/page_alloc.c: get rid of __alloc_pages_high_priority()
__alloc_pages_high_priority doesn't do anything special other than it
calls get_page_from_freelist and loops around GFP_NOFAIL allocation
until it succeeds. It would be better if the first part was done in
__alloc_pages_slowpath where we modify the zonelist because this would
be easier to read and understand. Opencoding the function into its only
caller allows to simplify it a bit as well.
This patch doesn't introduce any functional changes.
Since commit a0b8cab3b9b2 ("mm: remove lru parameter from
__pagevec_lru_add and remove parts of pagevec API") there's no
user of this function anymore, so remove it.
Yaowei Bai [Thu, 14 Jan 2016 23:18:54 +0000 (15:18 -0800)]
mm/memblock.c: memblock_is_memory()/reserved() can be boolean
Make memblock_is_memory() and memblock_is_reserved return bool to
improve readability due to these particular functions only using either
one or zero as their return value.
yalin wang [Thu, 14 Jan 2016 23:18:48 +0000 (15:18 -0800)]
mm: change mm_vmscan_lru_shrink_inactive() proto types
Move node_id zone_idx shrink flags into trace function, so thay we don't
need caculate these args if the trace is disabled, and will make this
function have less arguments.
Joonsoo Kim [Thu, 14 Jan 2016 23:18:45 +0000 (15:18 -0800)]
mm/cma: always check which page caused allocation failure
Now, we have tracepoint in test_pages_isolated() to notify pfn which
cannot be isolated. But, in alloc_contig_range(), some error path
doesn't call test_pages_isolated() so it's still hard to know exact pfn
that causes allocation failure.
This patch change this situation by calling test_pages_isolated() in
almost error path. In allocation failure case, some overhead is added
by this change, but, allocation failure is really rare event so it would
not matter.
In fatal signal pending case, we don't call test_pages_isolated()
because this failure is intentional one.
There was a bogus outer_start problem due to unchecked buddy order and
this patch also fix it. Before this patch, it didn't matter, because
end result is same thing. But, after this patch, tracepoint will report
failed pfn so it should be accurate.
Joonsoo Kim [Thu, 14 Jan 2016 23:18:42 +0000 (15:18 -0800)]
mm/page_isolation.c: add new tracepoint, test_pages_isolated
cma allocation should be guranteeded to succeed. But sometimes it can
fail in the current implementation. To track down the problem, we need
to know which page is problematic and this new tracepoint will report
it.
Joonsoo Kim [Thu, 14 Jan 2016 23:18:39 +0000 (15:18 -0800)]
mm/page_isolation.c: return last tested pfn rather than failure indicator
This is preparation step to report test failed pfn in new tracepoint to
analyze cma allocation failure problem. There is no functional change
in this patch.
Nathan Zimmer [Thu, 14 Jan 2016 23:18:36 +0000 (15:18 -0800)]
mm/mempolicy.c: convert the shared_policy lock to a rwlock
When running the SPECint_rate gcc on some very large boxes it was
noticed that the system was spending lots of time in
mpol_shared_policy_lookup(). The gamess benchmark can also show it and
is what I mostly used to chase down the issue since the setup for that I
found to be easier.
To be clear the binaries were on tmpfs because of disk I/O requirements.
We then used text replication to avoid icache misses and having all the
copies banging on the memory where the instruction code resides. This
results in us hitting a bottleneck in mpol_shared_policy_lookup() since
lookup is serialised by the shared_policy lock.
I have only reproduced this on very large (3k+ cores) boxes. The
problem starts showing up at just a few hundred ranks getting worse
until it threatens to livelock once it gets large enough. For example
on the gamess benchmark at 128 ranks this area consumes only ~1% of
time, at 512 ranks it consumes nearly 13%, and at 2k ranks it is over
90%.
To alleviate the contention in this area I converted the spinlock to an
rwlock. This allows a large number of lookups to happen simultaneously.
The results were quite good reducing this consumtion at max ranks to
around 2%.
Vladimir Davydov [Thu, 14 Jan 2016 23:18:21 +0000 (15:18 -0800)]
kmemcg: account certain kmem allocations to memcg
Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg. For the list, see below:
- threadinfo
- task_struct
- task_delay_info
- pid
- cred
- mm_struct
- vm_area_struct and vm_region (nommu)
- anon_vma and anon_vma_chain
- signal_struct
- sighand_struct
- fs_struct
- files_struct
- fdtable and fdtable->full_fds_bits
- dentry and external_name
- inode for all filesystems. This is the most tedious part, because
most filesystems overwrite the alloc_inode method.
The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds. Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).
Vladimir Davydov [Thu, 14 Jan 2016 23:18:18 +0000 (15:18 -0800)]
vmalloc: allow to account vmalloc to memcg
Make vmalloc family functions allocate vmalloc area pages with
alloc_kmem_pages so that if __GFP_ACCOUNT is set they will be accounted
to memcg. This is needed, at least, to account alloc_fdmem allocations.
Vladimir Davydov [Thu, 14 Jan 2016 23:18:15 +0000 (15:18 -0800)]
slab: add SLAB_ACCOUNT flag
Currently, if we want to account all objects of a particular kmem cache,
we have to pass __GFP_ACCOUNT to each kmem_cache_alloc call, which is
inconvenient. This patch introduces SLAB_ACCOUNT flag which if passed
to kmem_cache_create will force accounting for every allocation from
this cache even if __GFP_ACCOUNT is not passed.
This patch does not make any of the existing caches use this flag - it
will be done later in the series.
Note, a cache with SLAB_ACCOUNT cannot be merged with a cache w/o
SLAB_ACCOUNT, because merged caches share the same kmem_cache struct and
hence cannot have different sets of SLAB_* flags. Thus using this flag
will probably reduce the number of merged slabs even if kmem accounting
is not used (only compiled in).
Vladimir Davydov [Thu, 14 Jan 2016 23:18:12 +0000 (15:18 -0800)]
memcg: only account kmem allocations marked as __GFP_ACCOUNT
Black-list kmem accounting policy (aka __GFP_NOACCOUNT) turned out to be
fragile and difficult to maintain, because there seem to be many more
allocations that should not be accounted than those that should be.
Besides, false accounting an allocation might result in much worse
consequences than not accounting at all, namely increased memory
consumption due to pinned dead kmem caches.
So this patch switches kmem accounting to the white-policy: now only
those kmem allocations that are marked as __GFP_ACCOUNT are accounted to
memcg. Currently, no kmem allocations are marked like this. The
following patches will mark several kmem allocations that are known to
be easily triggered from userspace and therefore should be accounted to
memcg.
Vladimir Davydov [Thu, 14 Jan 2016 23:18:08 +0000 (15:18 -0800)]
Revert "gfp: add __GFP_NOACCOUNT"
This reverts commit 8f4fc071b192 ("gfp: add __GFP_NOACCOUNT").
Black-list kmem accounting policy (aka __GFP_NOACCOUNT) turned out to be
fragile and difficult to maintain, because there seem to be many more
allocations that should not be accounted than those that should be.
Besides, false accounting an allocation might result in much worse
consequences than not accounting at all, namely increased memory
consumption due to pinned dead kmem caches.
So it was decided to switch to the white-list policy. This patch
reverts bits introducing the black-list policy. The white-list policy
will be introduced later in the series.
Vladimir Davydov [Thu, 14 Jan 2016 23:18:05 +0000 (15:18 -0800)]
Revert "kernfs: do not account ino_ida allocations to memcg"
Currently, all kmem allocations (namely every kmem_cache_alloc, kmalloc,
alloc_kmem_pages call) are accounted to memory cgroup automatically.
Callers have to explicitly opt out if they don't want/need accounting
for some reason. Such a design decision leads to several problems:
- kmalloc users are highly sensitive to failures, many of them
implicitly rely on the fact that kmalloc never fails, while memcg
makes failures quite plausible.
- A lot of objects are shared among different containers by design.
Accounting such objects to one of containers is just unfair.
Moreover, it might lead to pinning a dead memcg along with its kmem
caches, which aren't tiny, which might result in noticeable increase
in memory consumption for no apparent reason in the long run.
- There are tons of short-lived objects. Accounting them to memcg will
only result in slight noise and won't change the overall picture, but
we still have to pay accounting overhead.
Therefore this patchset switches to the white list policy. Now kmalloc
users have to explicitly opt in by passing __GFP_ACCOUNT flag.
Currently, the list of accounted objects is quite limited and only
includes those allocations that (1) are known to be easily triggered
from userspace and (2) can fail gracefully (for the full list see patch
no. 6) and it still misses many object types. However, accounting only
those objects should be a satisfactory approximation of the behavior we
used to have for most sane workloads.
Black-list kmem accounting policy (aka __GFP_NOACCOUNT) turned out to be
fragile and difficult to maintain, because there seem to be many more
allocations that should not be accounted than those that should be.
Besides, false accounting an allocation might result in much worse
consequences than not accounting at all, namely increased memory
consumption due to pinned dead kmem caches.
So it was decided to switch to the white-list policy. This patch reverts
bits introducing the black-list policy. The white-list policy will be
introduced later in the series.
Joseph Qi [Thu, 14 Jan 2016 23:17:44 +0000 (15:17 -0800)]
ocfs2: access orphan dinode before delete entry in ocfs2_orphan_del
In ocfs2_orphan_del, currently it finds and deletes entry first, and
then access orphan dir dinode. This will have a problem once
ocfs2_journal_access_di fails. In this case, entry will be removed from
orphan dir, but in deed the inode hasn't been deleted successfully. In
other words, the file is missing but not actually deleted. So we should
access orphan dinode first like unlink and rename.
xuejiufei [Thu, 14 Jan 2016 23:17:41 +0000 (15:17 -0800)]
ocfs2/dlm: do not insert a new mle when another process is already migrating
When two processes are migrating the same lockres,
dlm_add_migration_mle() return -EEXIST, but insert a new mle in hash
list. dlm_migrate_lockres() will detach the old mle and free the new
one which is already in hash list, that will destroy the list.
xuejiufei [Thu, 14 Jan 2016 23:17:38 +0000 (15:17 -0800)]
ocfs2/dlm: ignore cleaning the migration mle that is inuse
We have found that migration source will trigger a BUG that the refcount
of mle is already zero before put when the target is down during
migration. The situation is as follows:
dlm_migrate_lockres
dlm_add_migration_mle
dlm_mark_lockres_migrating
dlm_get_mle_inuse
<<<<<< Now the refcount of the mle is 2.
dlm_send_one_lockres and wait for the target to become the
new master.
<<<<<< o2hb detect the target down and clean the migration
mle. Now the refcount is 1.
dlm_migrate_lockres woken, and put the mle twice when found the target
goes down which trigger the BUG with the following message:
jiangyiwen [Thu, 14 Jan 2016 23:17:33 +0000 (15:17 -0800)]
ocfs2: fix slot overwritten if storage link down during mount
The following case will lead to slot overwritten.
N1 N2
mount ocfs2 volume, find and
allocate slot 0, then set
osb->slot_num to 0, begin to
write slot info to disk
mount ocfs2 volume, wait for super lock
write block fail because of
storage link down, unlock
super lock
got super lock and also allocate slot 0
then unlock super lock
mount fail and then dismount,
since osb->slot_num is 0, try to
put invalid slot to disk. And it
will succeed if storage link
restores.
N2 slot info is now overwritten
Once another node say N3 mount, it will find and allocate slot 0 again,
which will lead to mount hung because journal has already been locked by
N2. so when write slot info failed, invalidate slot in advance to avoid
overwrite slot.
Xue jiufei [Thu, 14 Jan 2016 23:17:29 +0000 (15:17 -0800)]
ocfs2/dlm: return appropriate value when dlm_grab() returns NULL
dlm_grab() may return NULL when the node is doing unmount. When doing
code review, we found that some dlm handlers may return error to caller
when dlm_grab() returns NULL and make caller BUG or other problems.
Here is an example:
Node 1 Node 2
receives migration message
from node 3, and send
migrate request to others
start unmounting
receives migrate request
from node 1 and call
dlm_migrate_request_handler()
unmount thread unregisters
domain handlers and removes
dlm_context from dlm_domains
dlm_migrate_request_handlers()
returns -EINVAL to node 1
Exit migration neither clearing the
migration state nor sending
assert master message to node 3 which
cause node 3 hung.
jiangyiwen [Thu, 14 Jan 2016 23:17:23 +0000 (15:17 -0800)]
ocfs2/dlm: wait until DLM_LOCK_RES_SETREF_INPROG is cleared in dlm_deref_lockres_worker
Commit f3f854648de6 ("ocfs2_dlm: Ensure correct ordering of set/clear
refmap bit on lockres") still exists a race which can't ensure the
ordering is exactly correct.
Node1 Node2 Node3
umount, migrate
lockres to Node2
migrate finished,
send migrate request
to Node3
received migrate request,
create a migration_mle,
respond to Node2.
set DLM_LOCK_RES_SETREF_INPROG
and send assert master to
Node3
delete migration_mle in
assert_master_handler,
Node3 umount without response
dlm_thread purge
this lockres, send drop
deref message to Node2
found the flag of
DLM_LOCK_RES_SETREF_INPROG
is set, dispatch
dlm_deref_lockres_worker to
clear refmap, but in function of
dlm_deref_lockres_worker,
only if node in refmap it wait
DLM_LOCK_RES_SETREF_INPROG
to be cleared. So worker is
done successfully
purge lockres, send
assert master response
to Node1, and finish umount
set Node3 in refmap, and it
won't be cleared forever, thus
lead to umount hung
so wait until DLM_LOCK_RES_SETREF_INPROG is cleared in
dlm_deref_lockres_worker.
Xue jiufei [Thu, 14 Jan 2016 23:17:18 +0000 (15:17 -0800)]
ocfs2/dlm: fix a race between purge and migration
We found a race between purge and migration when doing code review.
Node A put lockres to purgelist before receiving the migrate message
from node B which is the master. Node A call dlm_mig_lockres_handler to
handle this message.
dlm_mig_lockres_handler
dlm_lookup_lockres
>>>>>> race window, dlm_run_purge_list may run and send
deref message to master, waiting the response
spin_lock(&res->spinlock);
res->state |= DLM_LOCK_RES_MIGRATING;
spin_unlock(&res->spinlock);
dlm_mig_lockres_handler returns
>>>>>> dlm_thread receives the response from master for the deref
message and triggers the BUG because the lockres has the state
DLM_LOCK_RES_MIGRATING with the following message:
Stabilize heartbeat depends on the timing order to mount ocfs2 from
cluster nodes and how fast the tcp connections are established. So
increase unsteady interations to leave more time for it.
John Haxby [Thu, 14 Jan 2016 23:17:12 +0000 (15:17 -0800)]
ocfs2: return non-zero st_blocks for inline data
Some versions of tar assume that files with st_blocks == 0 do not
contain any data and will skip reading them entirely. See also commit 9206c561554c ("ext4: return non-zero st_blocks for inline data").
Arnd Bergmann [Thu, 14 Jan 2016 23:17:05 +0000 (15:17 -0800)]
logfs: fix logfs build errors and dependencies
Fix build errors that happen when CONFIG_LOGFS=y and CONFIG_MTD=m:
fs/built-in.o: In function `logfs_mount':
super.c:(.text+0x92a6f): undefined reference to `logfs_get_sb_mtd'
fs/built-in.o: In function `logfs_get_sb_bdev':
(.text+0x93530): undefined reference to `logfs_get_sb_mtd'
This patch avoids the error by changing the dependencies of logfs in a
way that we can no longer configure logfs as built-in when the MTD core
is a loadable module, while leaving the dependency to require at least
one of MTD or BLOCK to be enabled.
modpost: don't add a trailing wildcard for OF module aliases
Commit ac551828993e ("modpost: i2c aliases need no trailing wildcard")
removed the wildcard at the end of the I2C module aliases because I2C
devices have no IDs so the aliases are just arbitrary device names.
This is also true for OF modaliases since a compatible string is used to
define a specific IP hardware block. So the modalias should match a
specific compatible string and not attempt to match a compatible string
whose name matches the beginning of another one.
For example, the following driver module:
$ modinfo cros_ec_keyb | grep alias
alias: platform:cros-ec-keyb
alias: of:N*T*Cgoogle,cros-ec-keyb*
will be tried to be loaded for an alias of:N*T*Cgoogle,cros-ec-keyb-v2
but there could be a different driver that supports the device for that
compatible string so it's better to remove the trailing wildcard for OF.
Also, remove the word "always" from the add_wildcard() function comment
since that was carried from the time where a wildcard was always added
at the end of the module alias for all the devices.
Jeff Layton [Thu, 14 Jan 2016 23:16:59 +0000 (15:16 -0800)]
fsnotify: destroy marks with call_srcu instead of dedicated thread
At the time that this code was originally written, call_srcu didn't
exist, so this thread was required to ensure that we waited for that
SRCU grace period to settle before finally freeing the object.
It does exist now however and we can much more efficiently use call_srcu
to handle this. That also allows us to potentially use srcu_barrier to
ensure that they are all of the callbacks have run before proceeding.
In order to conserve space, we union the rcu_head with the g_list.
This will be necessary for nfsd which will allocate marks from a
dedicated slabcache. We have to be able to ensure that all of the
objects are destroyed before destroying the cache. That's fairly
Laura Abbott [Thu, 14 Jan 2016 23:16:50 +0000 (15:16 -0800)]
dma-debug: switch check from _text to _stext
In include/asm-generic/sections.h:
/*
* Usage guidelines:
* _text, _data: architecture specific, don't use them in
* arch-independent code
* [_stext, _etext]: contains .text.* sections, may also contain
* .rodata.*
* and/or .init.* sections
_text is not guaranteed across architectures. Architectures such as ARM
may reuse parts which are not actually text and erroneously trigger a bug.
Switch to using _stext which is guaranteed to contain text sections.
Came out of https://lkml.kernel.org/g/<567B1176.4000106@redhat.com>
Al Viro [Thu, 14 Jan 2016 22:52:59 +0000 (17:52 -0500)]
Make sure that highmem pages are not added to symlink page cache
inode_nohighmem() is sufficient to make sure that page_get_link()
won't try to allocate a highmem page. Moreover, it is sufficient
to make sure that page_symlink/__page_symlink won't do the same
thing. However, any filesystem that manually preseeds the symlink's
page cache upon symlink(2) needs to make sure that the page it
inserts there won't be a highmem one.
Fortunately, only nfs and shmem have run afoul of that...
Jeff Layton [Tue, 17 Nov 2015 11:52:23 +0000 (06:52 -0500)]
nfsd: add new io class tracepoint
Add some new tracepoints in the nfsd read/write codepaths. The idea
is that this will give us the ability to measure how long each phase of
a read or write operation takes.
Currently, NUMA node distance matrix is initialized only
when a machine descriptor (MD) exists. However, sun4u
machines (e.g. Sun Blade 2500) do not have an MD and thus
distance values were left uninitialized. The initialization
is now moved such that it happens on both sun4u and sun4v.
Markus Elfring [Thu, 14 Jan 2016 14:46:28 +0000 (15:46 +0100)]
fsl/fman: Delete one function call "put_device" in dtsec_config()
The Coccinelle semantic patch script "deref_null.cocci" pointed a problem
out in the implementation of the function "dtsec_config".
A null pointer was assigned to the data structure member "tbiphy" of the
variable "dtsec" if a matching device was not found.
A call of the function "put_device" was unnecessary then because
a previous call of the function "get_device" was not triggered.
Thus remove the function call "put_device" after the printing of the
desired error message.
Linus Torvalds [Thu, 14 Jan 2016 19:57:22 +0000 (11:57 -0800)]
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Misc changes:
- fix lguest bug
- fix /proc/meminfo output on certain configs
- fix pvclock bug
- fix reboot on certain iMacs by adding new reboot quirk
- fix bootup crash
- fix FPU boot line option parsing
- add more x86 self-tests
- small cleanups, documentation improvements, etc"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu/amd: Remove an unneeded condition in srat_detect_node()
x86/vdso/pvclock: Protect STABLE check with the seqcount
x86/mm: Improve switch_mm() barrier comments
selftests/x86: Test __kernel_sigreturn and __kernel_rt_sigreturn
x86/reboot/quirks: Add iMac10,1 to pci_reboot_dmi_table[]
lguest: Map switcher text R/O
x86/boot: Hide local labels in verify_cpu()
x86/fpu: Disable AVX when eagerfpu is off
x86/fpu: Disable MPX when eagerfpu is off
x86/fpu: Disable XGETBV1 when no XSAVE
x86/fpu: Fix early FPU command-line parsing
x86/mm: Use PAGE_ALIGNED instead of IS_ALIGNED
selftests/x86: Disable the ldt_gdt_64 test for now
x86/mm/pat: Make split_page_count() check for empty levels to fix /proc/meminfo output
x86/boot: Double BOOT_HEAP_SIZE to 64KB
x86/mm: Add barriers and document switch_mm()-vs-flush synchronization
Linus Torvalds [Thu, 14 Jan 2016 19:39:09 +0000 (11:39 -0800)]
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
"Tooling fixes, the biggest patch is one that decouples the kernel's
list.h from tooling list.h"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
perf tools: Fallback to srcdir/Documentation/tips.txt
perf ui/tui: Print helpline message as is
perf tools: Set and pass DOCDIR to builtin-report.c
perf tools: Add file_only config option to strlist
perf tools: Add more usage tips
perf record: Add --buildid-all option
tools subcmd: Add missing NORETURN define for parse-options.h
tools: Fix formatting of the "make -C tools" help message
tools: Make list.h self-sufficient
perf tools: Fix mmap2 event allocation in synthesize code
perf stat: Fix recort_usage typo
perf test: Reset err after using it hold errcode in hist testcases
perf test: Fix false TEST_OK result for 'perf test hist'
tools build: Add BPF feature check to test-all
perf bpf: Fix build breakage due to libbpf
tools: Move Makefile.arch from perf/config to tools/scripts
perf tools: Fix PowerPC native building
perf tools: Fix phony build target for build-test
perf tools: Add -lutil in python lib list for broken python-config
perf tools: Add missing sources to perf's MANIFEST
...
Linus Torvalds [Thu, 14 Jan 2016 19:25:37 +0000 (11:25 -0800)]
Merge branch 'i2c/for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
"Quite some driver updates:
- piix4 can now handle multiplexed adapters
- brcmstb, xlr, eg20t, designware drivers support more SoCs
- emev2 gained i2c slave support
- img-scb and rcar got bigger refactoring to remove issues
- lots of common driver updates
i2c core changes:
- new quirk flag when an adapter does not support clock stretching,
so clients can be configured to avoid that if possible
- added a helper function to retrieve timing parameters from firmware
(with rcar being the first user)
- "multi-master" DT binding added so drivers can adapt to this
setting (like disabling PM to keep arbitration working)
- RuntimePM for the logical adapter device is now always enabled by
the core to ensure propagation from childs to the parent (the HW
device)
- new macro builtin_i2c_driver to reduce boilerplate"
* 'i2c/for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (70 commits)
i2c: create builtin_i2c_driver to avoid registration boilerplate
i2c: imx: fix i2c resource leak with dma transfer
dt-bindings: i2c: eeprom: add another EEPROM device
dt-bindings: move I2C eeprom descriptions to the proper file
i2c: designware: Do not require clock when SSCN and FFCN are provided
DT: i2c: trivial-devices: Add Epson RX8010 and MPL3115
i2c: s3c2410: remove superfluous runtime PM calls
i2c: always enable RuntimePM for the adapter device
i2c: designware: retry transfer on transient failure
i2c: ibm_iic: rename i2c_timings struct due to clash with generic version
i2c: designware: Add support for AMD Seattle I2C
i2c: imx: Remove unneeded comments
i2c: st: use to_platform_device()
i2c: designware: use to_pci_dev()
i2c: brcmstb: Adding support for CM and DSL SoCs
i2c: mediatek: fix i2c multi transfer issue in high speed mode
i2c: imx: improve code readability
i2c: imx: Improve message log when DMA is not used
i2c: imx: add runtime pm support to improve the performance
i2c: imx: init bus recovery info before adding i2c adapter
...
Linus Torvalds [Thu, 14 Jan 2016 18:53:15 +0000 (10:53 -0800)]
Merge tag 'mfd-for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd
Pull MFD updates from Lee Jones:
"New Device Support:
- Add support for s2mps15; sec-core
- Add support for Lewisburg; lpc_ich
- Add support for cs47l24 and wm1831; arizona
New Functionality:
- Allow user to select syscon register width; syscon
* tag 'mfd-for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (58 commits)
mfd: davinci_voicecodec: Remove pointless 'out of memory' error message
mfd: da9052-irq: Fix trivial 'space before comma' error
mfd: da9052-i2c: Fix tabbing/whitespace issue
mfd: da903x: Fix white space and split string issues
mfd: cs5535-mfd: Add missing line spacing and make local array static
mfd: cros_ec_spi: Repair comparison ordering issue
mfd: cros_ec_i2c: Fix trivial 'tabs before spaces' whitespace issue.
mfd: asic3: Fix a plethora of Checkpatch errors and warnings
mfd: as3711: Repair OOM and 'line over 80 chars' formatting warnings
mfd: arizona-i2c: Add blank line formatting after declaration
mfd: arizona-core: msleep() is unreliable for anything <20ms use usleep_range() instead
mfd: adp5520: Some trivial 'no space before tab' fixes
mfd: ab8500-sysctrl: Fix Constify, printk => pr_info and formatting issues
mfd: ab8500-gpadc: Squash a whole bunch of Checkpatch warnings and one error
mfd: ab8500-debugfs: Clean-up non-conforming commenting and print formatting
mfd: ab8500-core: Fix many warnings reported by Checkpatch
mfd: ab2100-otp: Remove pointless 'out of memory' error message
mfd: ab3100-core.c: Fix multiple warnings reported by Checkpatch
mfd: aat2870-core: Remove unnecessary 'out of memory' message
mfd: 88pm860x-core: Fix commenting and declaration spacing
...
Linus Torvalds [Thu, 14 Jan 2016 18:45:11 +0000 (10:45 -0800)]
Merge tag 'for-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply
Pull power supply and reset updates from Sebastian Reichel:
"I have mostly fixes in the power-supply tree for the 4.5 kernel. I
should mention, that the top-most commit has not been in next, but
it's a fix changing only a single register offset.
Summary:
- uncouple CONFIG_POWER_RESET from CONFIG_POWER_SUPPLY
- misc fixes"
* tag 'for-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply:
power: bq27xxx_battery: Fix bq27541 AveragePower register address
power: test_power: correctly handle empty writes
power: generic-adc-battery: use to_delayed_work
power: isp1704_charger: Fix isp1704_write() definition
power: bq27xxx: fix register numbers of bq27500
power: bq27xxx: fix reading for bq27000 and bq27010
power: Fix unmet dependency on POWER_SUPPLY by POWER_RESET by uncoupling them
power: bq27xxx_battery: Reorganize I2C into a module
power: bq27xxx: don't fill system log by missing battery
power: max8903_charger: set IRQF_ONESHOT if no primary handler is specified
power/reset: at91-reset: add missing of_node_put
power: ds2782_battery: constify ds278x_battery_ops structure
power: bq2415x_charger: Delete unnecessary checks before the function call "of_node_put"
Linus Torvalds [Thu, 14 Jan 2016 18:40:16 +0000 (10:40 -0800)]
Merge tag 'hsi-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-hsi
Pull HSI updates from Sebastian Reichel:
"Misc fixes"
* tag 'hsi-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-hsi:
HSI: omap_ssi_port: fix handling of_get_named_gpio result
HSI: omap_ssi: fix handling ida_simple_get result
HSI: Remove struct hsi_client private fields from kernel-doc
* tag 'backlight-for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
backlight: pwm_bl: Free PWM requested by legacy API on error path
backlight: adp8860: Fix another uninitialized variable use
backlight: gpio-backlight: Use default-on on GPIO request
backlight: pwm_bl: Fix broken PWM backlight for non-dt platforms
backlight: tps65217_bl: Add MODULE_DEVICE_TABLE
backlight: pwm_bl: Avoid backlight flicker when probed from DT
backlight: adp88x0: Fix uninitialized variable use
Dmitry V. Levin [Sat, 26 Dec 2015 23:13:27 +0000 (02:13 +0300)]
sparc64: fix incorrect sign extension in sys_sparc64_personality
The value returned by sys_personality has type "long int".
It is saved to a variable of type "int", which is not a problem
yet because the type of task_struct->pesonality is "unsigned int".
The problem is the sign extension from "int" to "long int"
that happens on return from sys_sparc64_personality.
For example, a userspace call personality((unsigned) -EINVAL) will
result to any subsequent personality call, including absolutely
harmless read-only personality(0xffffffff) call, failing with
errno set to EINVAL.
Lee Jones [Wed, 28 Oct 2015 14:11:23 +0000 (14:11 +0000)]
mfd: asic3: Fix a plethora of Checkpatch errors and warnings
ERROR: Macros with complex values should be enclosed in parentheses
+#define INIT_CDEX(_name, _rate) \
+ [ASIC3_CLOCK_##_name] = { \
+ .cdex = CLOCK_CDEX_##_name, \
+ .rate = _rate, \
+ }
WARNING: line over 80 characters
+ ASIC3_GPIO_INT_STATUS);
WARNING: void function return statements are not generally useful
+ return;
+}
WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
+ msleep(1);
WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
+ msleep(1);
WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
+ msleep(1);
WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
+ msleep(1);
WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
+ msleep(1);
WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
+ msleep(1);
WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
+ msleep(1);
WARNING: line over 80 characters
+ asic->tmio_cnf = ioremap((ASIC3_SD_CONFIG_BASE >> asic->bus_shift) +
WARNING: Prefer [subsystem eg: netdev]_err([subsystem]dev, ... then dev_err(dev, ... then p
r_err(... to printk(KERN_ERR ...
+ printk(KERN_ERR "kzalloc failed\n");
WARNING: Possible unnecessary 'out of memory' message
+ if (asic == NULL) {
+ printk(KERN_ERR "kzalloc failed\n");
WARNING: Missing a blank line after declarations
+ int retval = 0;
+ retval = platform_driver_probe(&asic3_device_driver, asic3_probe);
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