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Dave Chinner reported a problem pointing a finger at commit 1c30844d2dfe
("mm: reclaim small amounts of memory when an external fragmentation
event occurs").
The report is extensive:
https://lore.kernel.org/linux-mm/20190807091858.2857-1-david@fromorbit.com/
and it's worth recording the most relevant parts (colorful language and
typos included).
When running a simple, steady state 4kB file creation test to
simulate extracting tarballs larger than memory full of small
files into the filesystem, I noticed that once memory fills up
the cache balance goes to hell.
The workload is creating one dirty cached inode for every dirty
page, both of which should require a single IO each to clean and
reclaim, and creation of inodes is throttled by the rate at which
dirty writeback runs at (via balance dirty pages). Hence the ingest
rate of new cached inodes and page cache pages is identical and
steady. As a result, memory reclaim should quickly find a steady
balance between page cache and inode caches.
The moment memory fills, the page cache is reclaimed at a much
faster rate than the inode cache, and evidence suggests that
the inode cache shrinker is not being called when large batches
of pages are being reclaimed. In roughly the same time period
that it takes to fill memory with 50% pages and 50% slab caches,
memory reclaim reduces the page cache down to just dirty pages
and slab caches fill the entirety of memory.
The LRU is largely full of dirty pages, and we're getting spikes
of random writeback from memory reclaim so it's all going to shit.
Behaviour never recovers, the page cache remains pinned at just
dirty pages, and nothing I could tune would make any difference.
vfs_cache_pressure makes no difference - I would set it so high
it should trim the entire inode caches in a single pass, yet it
didn't do anything. It was clear from tracing and live telemetry
that the shrinkers were pretty much not running except when
there was absolutely no memory free at all, and then they did
the minimum necessary to free memory to make progress.
So I went looking at the code, trying to find places where pages
got reclaimed and the shrinkers weren't called. There's only one
- kswapd doing boosted reclaim as per commit 1c30844d2dfe ("mm:
reclaim small amounts of memory when an external fragmentation
event occurs").
The watermark boosting introduced by the commit is triggered in response
to an allocation "fragmentation event". The boosting was not intended
to target THP specifically and triggers even if THP is disabled.
However, with Dave's perfectly reasonable workload, fragmentation events
can be very common given the ratio of slab to page cache allocations so
boosting remains active for long periods of time.
As high-order allocations might use compaction and compaction cannot
move slab pages the decision was made in the commit to special-case
kswapd when watermarks are boosted -- kswapd avoids reclaiming slab as
reclaiming slab does not directly help compaction.
As Dave notes, this decision means that slab can be artificially
protected for long periods of time and messes up the balance with slab
and page caches.
Removing the special casing can still indirectly help avoid
fragmentation by avoiding fragmentation-causing events due to slab
allocation as pages from a slab pageblock will have some slab objects
freed. Furthermore, with the special casing, reclaim behaviour is
unpredictable as kswapd sometimes examines slab and sometimes does not
in a manner that is tricky to tune or analyse.
This patch removes the special casing. The downside is that this is not
a universal performance win. Some benchmarks that depend on the
residency of data when rereading metadata may see a regression when slab
reclaim is restored to its original behaviour. Similarly, some
benchmarks that only read-once or write-once may perform better when
page reclaim is too aggressive. The primary upside is that slab
shrinker is less surprising (arguably more sane but that's a matter of
opinion), behaves consistently regardless of the fragmentation state of
the system and properly obeys VM sysctls.
A fsmark benchmark configuration was constructed similar to what Dave
reported and is codified by the mmtest configuration
config-io-fsmark-small-file-stream. It was evaluated on a 1-socket
machine to avoid dealing with NUMA-related issues and the timing of
reclaim. The storage was an SSD Samsung Evo and a fresh trimmed XFS
filesystem was used for the test data.
This is not an exact replication of Dave's setup. The configuration
scales its parameters depending on the memory size of the SUT to behave
similarly across machines. The parameters mean the first sample
reported by fs_mark is using 50% of RAM which will barely be throttled
and look like a big outlier. Dave used fake NUMA to have multiple
kswapd instances which I didn't replicate. Finally, the number of
iterations differ from Dave's test as the target disk was not large
enough. While not identical, it should be representative.
fsmark
5.3.0-rc3 5.3.0-rc3
vanilla shrinker-v1r1
Min 1-files/sec 4444.80 ( 0.00%) 4765.60 ( 7.22%)
1st-qrtle 1-files/sec 5005.10 ( 0.00%) 5091.70 ( 1.73%)
2nd-qrtle 1-files/sec 4917.80 ( 0.00%) 4855.60 ( -1.26%)
3rd-qrtle 1-files/sec 4667.40 ( 0.00%) 4831.20 ( 3.51%)
Max-1 1-files/sec 11421.50 ( 0.00%) 9999.30 ( -12.45%)
Max-5 1-files/sec 11421.50 ( 0.00%) 9999.30 ( -12.45%)
Max-10 1-files/sec 11421.50 ( 0.00%) 9999.30 ( -12.45%)
Max-90 1-files/sec 4649.60 ( 0.00%) 4780.70 ( 2.82%)
Max-95 1-files/sec 4491.00 ( 0.00%) 4768.20 ( 6.17%)
Max-99 1-files/sec 4491.00 ( 0.00%) 4768.20 ( 6.17%)
Max 1-files/sec 11421.50 ( 0.00%) 9999.30 ( -12.45%)
Hmean 1-files/sec 5004.75 ( 0.00%) 5075.96 ( 1.42%)
Stddev 1-files/sec 1778.70 ( 0.00%) 1369.66 ( 23.00%)
CoeffVar 1-files/sec 33.70 ( 0.00%) 26.05 ( 22.71%)
BHmean-99 1-files/sec 5053.72 ( 0.00%) 5101.52 ( 0.95%)
BHmean-95 1-files/sec 5053.72 ( 0.00%) 5101.52 ( 0.95%)
BHmean-90 1-files/sec 5107.05 ( 0.00%) 5131.41 ( 0.48%)
BHmean-75 1-files/sec 5208.45 ( 0.00%) 5206.68 ( -0.03%)
BHmean-50 1-files/sec 5405.53 ( 0.00%) 5381.62 ( -0.44%)
BHmean-25 1-files/sec 6179.75 ( 0.00%) 6095.14 ( -1.37%)
5.3.0-rc3 5.3.0-rc3
vanillashrinker-v1r1
Duration User 501.82 497.29
Duration System 4401.44 4424.08
Duration Elapsed 8124.76 8358.05
This is showing a slight skew for the max result representing a large
outlier for the 1st, 2nd and 3rd quartile are similar indicating that
the bulk of the results show little difference. Note that an earlier
version of the fsmark configuration showed a regression but that
included more samples taken while memory was still filling.
Note that the elapsed time is higher. Part of this is that the
configuration included time to delete all the test files when the test
completes -- the test automation handles the possibility of testing
fsmark with multiple thread counts. Without the patch, many of these
objects would be memory resident which is part of what the patch is
addressing.
There are other important observations that justify the patch.
1. With the vanilla kernel, the number of dirty pages in the system is
very low for much of the test. With this patch, dirty pages is
generally kept at 10% which matches vm.dirty_background_ratio which
is normal expected historical behaviour.
2. With the vanilla kernel, the ratio of Slab/Pagecache is close to
0.95 for much of the test i.e. Slab is being left alone and
dominating memory consumption. With the patch applied, the ratio
varies between 0.35 and 0.45 with the bulk of the measured ratios
roughly half way between those values. This is a different balance to
what Dave reported but it was at least consistent.
3. Slabs are scanned throughout the entire test with the patch applied.
The vanille kernel has periods with no scan activity and then
relatively massive spikes.
4. Without the patch, kswapd scan rates are very variable. With the
patch, the scan rates remain quite steady.
4. Overall vmstats are closer to normal expectations
5.3.0-rc3 5.3.0-rc3
vanilla shrinker-v1r1
Ops Direct pages scanned 99388.00 328410.00
Ops Kswapd pages scanned 45382917.00 33451026.00
Ops Kswapd pages reclaimed 30869570.00 25239655.00
Ops Direct pages reclaimed 74131.00 5830.00
Ops Kswapd efficiency % 68.02 75.45
Ops Kswapd velocity 5585.75 4002.25
Ops Page reclaim immediate 1179721.00 430927.00
Ops Slabs scanned 62367361.00 73581394.00
Ops Direct inode steals 2103.00 1002.00
Ops Kswapd inode steals 570180.00 5183206.00
o Vanilla kernel is hitting direct reclaim more frequently,
not very much in absolute terms but the fact the patch
reduces it is interesting
o "Page reclaim immediate" in the vanilla kernel indicates
dirty pages are being encountered at the tail of the LRU.
This is generally bad and means in this case that the LRU
is not long enough for dirty pages to be cleaned by the
background flush in time. This is much reduced by the
patch.
o With the patch, kswapd is reclaiming 10 times more slab
pages than with the vanilla kernel. This is indicative
of the watermark boosting over-protecting slab
A more complete set of tests were run that were part of the basis for
introducing boosting and while there are some differences, they are well
within tolerances.
Bottom line, the special casing kswapd to avoid slab behaviour is
unpredictable and can lead to abnormal results for normal workloads.
This patch restores the expected behaviour that slab and page cache is
balanced consistently for a workload with a steady allocation ratio of
slab/pagecache pages. It also means that if there are workloads that
favour the preservation of slab over pagecache that it can be tuned via
vm.vfs_cache_pressure where as the vanilla kernel effectively ignores
the parameter when boosting is active.
Link: http://lkml.kernel.org/r/20190808182946.GM2739@techsingularity.net
Fixes: 1c30844d2dfe ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org> [5.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This reverts commit 2f0799a0ffc033b ("mm, thp: restore node-local
hugepage allocations").
commit 2f0799a0ffc033b was rightfully applied to avoid the risk of a
severe regression that was reported by the kernel test robot at the end
of the merge window. Now we understood the regression was a false
positive and was caused by a significant increase in fairness during a
swap trashing benchmark. So it's safe to re-apply the fix and continue
improving the code from there. The benchmark that reported the
regression is very useful, but it provides a meaningful result only when
there is no significant alteration in fairness during the workload. The
removal of __GFP_THISNODE increased fairness.
__GFP_THISNODE cannot be used in the generic page faults path for new
memory allocations under the MPOL_DEFAULT mempolicy, or the allocation
behavior significantly deviates from what the MPOL_DEFAULT semantics are
supposed to be for THP and 4k allocations alike.
Setting THP defrag to "always" or using MADV_HUGEPAGE (with THP defrag
set to "madvise") has never meant to provide an implicit MPOL_BIND on
the "current" node the task is running on, causing swap storms and
providing a much more aggressive behavior than even zone_reclaim_node =
3.
Any workload who could have benefited from __GFP_THISNODE has now to
enable zone_reclaim_mode=1||2||3. __GFP_THISNODE implicitly provided
the zone_reclaim_mode behavior, but it only did so if THP was enabled:
if THP was disabled, there would have been no chance to get any 4k page
from the current node if the current node was full of pagecache, which
further shows how this __GFP_THISNODE was misplaced in MADV_HUGEPAGE.
MADV_HUGEPAGE has never been intended to provide any zone_reclaim_mode
semantics, in fact the two are orthogonal, zone_reclaim_mode = 1|2|3
must work exactly the same with MADV_HUGEPAGE set or not.
The performance characteristic of memory depends on the hardware
details. The numbers below are obtained on Naples/EPYC architecture and
the N/A projection extends them to show what we should aim for in the
future as a good THP NUMA locality default. The benchmark used
exercises random memory seeks (note: the cost of the page faults is not
part of the measurement).
D0 THP | D0 4k | D1 THP | D1 4k | D2 THP | D2 4k | D3 THP | D3 4k | ...
0% | +43% | +45% | +106% | +131% | +224% | N/A | N/A
D0 means distance zero (i.e. local memory), D1 means distance one (i.e.
intra socket memory), D2 means distance two (i.e. inter socket memory),
etc...
For the guest physical memory allocated by qemu and for guest mode
kernel the performance characteristic of RAM is more complex and an
ideal default could be:
D0 THP | D1 THP | D0 4k | D2 THP | D1 4k | D3 THP | D2 4k | D3 4k | ...
0% | +58% | +101% | N/A | +222% | N/A | N/A | N/A
NOTE: the N/A are projections and haven't been measured yet, the
measurement in this case is done on a 1950x with only two NUMA nodes.
The THP case here means THP was used both in the host and in the guest.
After applying this commit the THP NUMA locality order that we'll get
out of MADV_HUGEPAGE is this:
D0 THP | D1 THP | D2 THP | D3 THP | ... | D0 4k | D1 4k | D2 4k | D3 4k | ...
Before this commit it was:
D0 THP | D0 4k | D1 4k | D2 4k | D3 4k | ...
Even if we ignore the breakage of large workloads that can't fit in a
single node that the __GFP_THISNODE implicit "current node" mbind
caused, the THP NUMA locality order provided by __GFP_THISNODE was still
not the one we shall aim for in the long term (i.e. the first one at
the top).
After this commit is applied, we can introduce a new allocator multi
order API and to replace those two alloc_pages_vmas calls in the page
fault path, with a single multi order call:
unsigned int order = (1 << HPAGE_PMD_ORDER) | (1 << 0);
page = alloc_pages_multi_order(..., &order);
if (!page)
goto out;
if (!(order & (1 << 0))) {
VM_WARN_ON(order != 1 << HPAGE_PMD_ORDER);
/* THP fault */
} else {
VM_WARN_ON(order != 1 << 0);
/* 4k fallback */
}
The page allocator logic has to be altered so that when it fails on any
zone with order 9, it has to try again with a order 0 before falling
back to the next zone in the zonelist.
After that we need to do more measurements and evaluate if adding an
opt-in feature for guest mode is worth it, to swap "DN 4k | DN+1 THP"
with "DN+1 THP | DN 4k" at every NUMA distance crossing.
Link: http://lkml.kernel.org/r/20190503223146.2312-3-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Patch series "reapply: relax __GFP_THISNODE for MADV_HUGEPAGE mappings".
The fixes for what was originally reported as "pathological THP
behavior" we rightfully reverted to be sure not to introduced
regressions at end of a merge window after a severe regression report
from the kernel bot. We can safely re-apply them now that we had time
to analyze the problem.
The mm process worked fine, because the good fixes were eventually
committed upstream without excessive delay.
The regression reported by the kernel bot however forced us to revert
the good fixes to be sure not to introduce regressions and to give us
the time to analyze the issue further. The silver lining is that this
extra time allowed to think more at this issue and also plan for a
future direction to improve things further in terms of THP NUMA
locality.
This patch (of 2):
This reverts commit 356ff8a9a78fb35d ("Revert "mm, thp: consolidate THP
gfp handling into alloc_hugepage_direct_gfpmask"). So it reapplies
89c83fb539f954 ("mm, thp: consolidate THP gfp handling into
alloc_hugepage_direct_gfpmask").
Consolidation of the THP allocation flags at the same place was meant to
be a clean up to easier handle otherwise scattered code which is
imposing a maintenance burden. There were no real problems observed
with the gfp mask consolidation but the reversion was rushed through
without a larger consensus regardless.
This patch brings the consolidation back because this should make the
long term maintainability easier as well as it should allow future
changes to be less error prone.
[mhocko@kernel.org: changelog additions]
Link: http://lkml.kernel.org/r/20190503223146.2312-2-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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A compiler throws a warning on an arm64 system since commit 9849a5697d3d
("arch, mm: convert all architectures to use 5level-fixup.h"),
mm/kasan/init.c: In function 'kasan_free_p4d':
mm/kasan/init.c:344:9: warning: variable 'p4d' set but not used [-Wunused-but-set-variable]
p4d_t *p4d;
^~~
because p4d_none() in "5level-fixup.h" is compiled away while it is a
static inline function in "pgtable-nopud.h".
However, if converted p4d_none() to a static inline there, powerpc would
be unhappy as it reads those in assembler language in
"arch/powerpc/include/asm/book3s/64/pgtable.h", so it needs to skip
assembly include for the static inline C function.
While at it, converted a few similar functions to be consistent with the
ones in "pgtable-nopud.h".
Link: http://lkml.kernel.org/r/20190806232917.881-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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If you use lseek or similar (e.g. pread) to access a location in a
seq_file file that is within a record, rather than at a record boundary,
then the first read will return the remainder of the record, and the
second read will return the whole of that same record (instead of the
next record). When seeking to a record boundary, the next record is
correctly returned.
This bug was introduced by a recent patch (identified below). Before
that patch, seq_read() would increment m->index when the last of the
buffer was returned (m->count == 0). After that patch, we rely on
->next to increment m->index after filling the buffer - but there was
one place where that didn't happen.
Link: https://lkml.kernel.org/lkml/877e7xl029.fsf@notabene.neil.brown.name/
Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface")
Signed-off-by: NeilBrown <neilb@suse.com>
Reported-by: Sergei Turchanov <turchanov@farpost.com>
Tested-by: Sergei Turchanov <turchanov@farpost.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Markus Elfring <Markus.Elfring@web.de>
Cc: <stable@vger.kernel.org> [4.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Memcg counters for shadow nodes are broken because the memcg pointer is
obtained in a wrong way. The following approach is used:
virt_to_page(xa_node)->mem_cgroup
Since commit 4d96ba353075 ("mm: memcg/slab: stop setting
page->mem_cgroup pointer for slab pages") page->mem_cgroup pointer isn't
set for slab pages, so memcg_from_slab_page() should be used instead.
Also I doubt that it ever worked correctly: virt_to_head_page() should
be used instead of virt_to_page(). Otherwise objects residing on tail
pages are not accounted, because only the head page contains a valid
mem_cgroup pointer. That was a case since the introduction of these
counters by the commit 68d48e6a2df5 ("mm: workingset: add vmstat counter
for shadow nodes").
Link: http://lkml.kernel.org/r/20190801233532.138743-1-guro@fb.com
Fixes: 4d96ba353075 ("mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages")
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Currently, when checking to see if accessing n bytes starting at address
"ptr" will cause a wraparound in the memory addresses, the check in
check_bogus_address() adds an extra byte, which is incorrect, as the
range of addresses that will be accessed is [ptr, ptr + (n - 1)].
This can lead to incorrectly detecting a wraparound in the memory
address, when trying to read 4 KB from memory that is mapped to the the
last possible page in the virtual address space, when in fact, accessing
that range of memory would not cause a wraparound to occur.
Use the memory range that will actually be accessed when considering if
accessing a certain amount of bytes will cause the memory address to
wrap around.
Link: http://lkml.kernel.org/r/1564509253-23287-1-git-send-email-isaacm@codeaurora.org
Fixes: f5509cc18daa ("mm: Hardened usercopy")
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Co-developed-by: Prasad Sodagudi <psodagud@codeaurora.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Trilok Soni <tsoni@codeaurora.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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If an error occurs during kmemleak_init() (e.g. kmem cache cannot be
created), kmemleak is disabled but kmemleak_early_log remains enabled.
Subsequently, when the .init.text section is freed, the log_early()
function no longer exists. To avoid a page fault in such scenario,
ensure that kmemleak_disable() also disables early logging.
Link: http://lkml.kernel.org/r/20190731152302.42073-1-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Recent changes to the vmalloc code by commit 68ad4a330433
("mm/vmalloc.c: keep track of free blocks for vmap allocation") can
cause spurious percpu allocation failures. These, in turn, can result
in panic()s in the slub code. One such possible panic was reported by
Dave Hansen in following link https://lkml.org/lkml/2019/6/19/939.
Another related panic observed is,
RIP: 0033:0x7f46f7441b9b
Call Trace:
dump_stack+0x61/0x80
pcpu_alloc.cold.30+0x22/0x4f
mem_cgroup_css_alloc+0x110/0x650
cgroup_apply_control_enable+0x133/0x330
cgroup_mkdir+0x41b/0x500
kernfs_iop_mkdir+0x5a/0x90
vfs_mkdir+0x102/0x1b0
do_mkdirat+0x7d/0xf0
do_syscall_64+0x5b/0x180
entry_SYSCALL_64_after_hwframe+0x44/0xa9
VMALLOC memory manager divides the entire VMALLOC space (VMALLOC_START
to VMALLOC_END) into multiple VM areas (struct vm_areas), and it mainly
uses two lists (vmap_area_list & free_vmap_area_list) to track the used
and free VM areas in VMALLOC space. And pcpu_get_vm_areas(offsets[],
sizes[], nr_vms, align) function is used for allocating congruent VM
areas for percpu memory allocator. In order to not conflict with
VMALLOC users, pcpu_get_vm_areas allocates VM areas near the end of the
VMALLOC space. So the search for free vm_area for the given requirement
starts near VMALLOC_END and moves upwards towards VMALLOC_START.
Prior to commit 68ad4a330433, the search for free vm_area in
pcpu_get_vm_areas() involves following two main steps.
Step 1:
Find a aligned "base" adress near VMALLOC_END.
va = free vm area near VMALLOC_END
Step 2:
Loop through number of requested vm_areas and check,
Step 2.1:
if (base < VMALLOC_START)
1. fail with error
Step 2.2:
// end is offsets[area] + sizes[area]
if (base + end > va->vm_end)
1. Move the base downwards and repeat Step 2
Step 2.3:
if (base + start < va->vm_start)
1. Move to previous free vm_area node, find aligned
base address and repeat Step 2
But Commit 68ad4a330433 removed Step 2.2 and modified Step 2.3 as below:
Step 2.3:
if (base + start < va->vm_start || base + end > va->vm_end)
1. Move to previous free vm_area node, find aligned
base address and repeat Step 2
Above change is the root cause of spurious percpu memory allocation
failures. For example, consider a case where a relatively large vm_area
(~ 30 TB) was ignored in free vm_area search because it did not pass the
base + end < vm->vm_end boundary check. Ignoring such large free
vm_area's would lead to not finding free vm_area within boundary of
VMALLOC_start to VMALLOC_END which in turn leads to allocation failures.
So modify the search algorithm to include Step 2.2.
Link: http://lkml.kernel.org/r/20190729232139.91131-1-sathyanarayanan.kuppuswamy@linux.intel.com
Fixes: 68ad4a330433 ("mm/vmalloc.c: keep track of free blocks for vmap allocation")
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reported-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: sathyanarayanan kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This patch is sent to report an use after free in mem_cgroup_iter()
after merging commit be2657752e9e ("mm: memcg: fix use after free in
mem_cgroup_iter()").
I work with android kernel tree (4.9 & 4.14), and commit be2657752e9e
("mm: memcg: fix use after free in mem_cgroup_iter()") has been merged
to the trees. However, I can still observe use after free issues
addressed in the commit be2657752e9e. (on low-end devices, a few times
this month)
backtrace:
css_tryget <- crash here
mem_cgroup_iter
shrink_node
shrink_zones
do_try_to_free_pages
try_to_free_pages
__perform_reclaim
__alloc_pages_direct_reclaim
__alloc_pages_slowpath
__alloc_pages_nodemask
To debug, I poisoned mem_cgroup before freeing it:
static void __mem_cgroup_free(struct mem_cgroup *memcg)
for_each_node(node)
free_mem_cgroup_per_node_info(memcg, node);
free_percpu(memcg->stat);
+ /* poison memcg before freeing it */
+ memset(memcg, 0x78, sizeof(struct mem_cgroup));
kfree(memcg);
}
The coredump shows the position=0xdbbc2a00 is freed.
(gdb) p/x ((struct mem_cgroup_per_node *)0xe5009e00)->iter[8]
$13 = {position = 0xdbbc2a00, generation = 0x2efd}
0xdbbc2a00: 0xdbbc2e00 0x00000000 0xdbbc2800 0x00000100
0xdbbc2a10: 0x00000200 0x78787878 0x00026218 0x00000000
0xdbbc2a20: 0xdcad6000 0x00000001 0x78787800 0x00000000
0xdbbc2a30: 0x78780000 0x00000000 0x0068fb84 0x78787878
0xdbbc2a40: 0x78787878 0x78787878 0x78787878 0xe3fa5cc0
0xdbbc2a50: 0x78787878 0x78787878 0x00000000 0x00000000
0xdbbc2a60: 0x00000000 0x00000000 0x00000000 0x00000000
0xdbbc2a70: 0x00000000 0x00000000 0x00000000 0x00000000
0xdbbc2a80: 0x00000000 0x00000000 0x00000000 0x00000000
0xdbbc2a90: 0x00000001 0x00000000 0x00000000 0x00100000
0xdbbc2aa0: 0x00000001 0xdbbc2ac8 0x00000000 0x00000000
0xdbbc2ab0: 0x00000000 0x00000000 0x00000000 0x00000000
0xdbbc2ac0: 0x00000000 0x00000000 0xe5b02618 0x00001000
0xdbbc2ad0: 0x00000000 0x78787878 0x78787878 0x78787878
0xdbbc2ae0: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2af0: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b00: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b10: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b20: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b30: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b40: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b50: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b60: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b70: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2b80: 0x78787878 0x78787878 0x00000000 0x78787878
0xdbbc2b90: 0x78787878 0x78787878 0x78787878 0x78787878
0xdbbc2ba0: 0x78787878 0x78787878 0x78787878 0x78787878
In the reclaim path, try_to_free_pages() does not setup
sc.target_mem_cgroup and sc is passed to do_try_to_free_pages(), ...,
shrink_node().
In mem_cgroup_iter(), root is set to root_mem_cgroup because
sc->target_mem_cgroup is NULL. It is possible to assign a memcg to
root_mem_cgroup.nodeinfo.iter in mem_cgroup_iter().
try_to_free_pages
struct scan_control sc = {...}, target_mem_cgroup is 0x0;
do_try_to_free_pages
shrink_zones
shrink_node
mem_cgroup *root = sc->target_mem_cgroup;
memcg = mem_cgroup_iter(root, NULL, &reclaim);
mem_cgroup_iter()
if (!root)
root = root_mem_cgroup;
...
css = css_next_descendant_pre(css, &root->css);
memcg = mem_cgroup_from_css(css);
cmpxchg(&iter->position, pos, memcg);
My device uses memcg non-hierarchical mode. When we release a memcg:
invalidate_reclaim_iterators() reaches only dead_memcg and its parents.
If non-hierarchical mode is used, invalidate_reclaim_iterators() never
reaches root_mem_cgroup.
static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg)
{
struct mem_cgroup *memcg = dead_memcg;
for (; memcg; memcg = parent_mem_cgroup(memcg)
...
}
So the use after free scenario looks like:
CPU1 CPU2
try_to_free_pages
do_try_to_free_pages
shrink_zones
shrink_node
mem_cgroup_iter()
if (!root)
root = root_mem_cgroup;
...
css = css_next_descendant_pre(css, &root->css);
memcg = mem_cgroup_from_css(css);
cmpxchg(&iter->position, pos, memcg);
invalidate_reclaim_iterators(memcg);
...
__mem_cgroup_free()
kfree(memcg);
try_to_free_pages
do_try_to_free_pages
shrink_zones
shrink_node
mem_cgroup_iter()
if (!root)
root = root_mem_cgroup;
...
mz = mem_cgroup_nodeinfo(root, reclaim->pgdat->node_id);
iter = &mz->iter[reclaim->priority];
pos = READ_ONCE(iter->position);
css_tryget(&pos->css) <- use after free
To avoid this, we should also invalidate root_mem_cgroup.nodeinfo.iter
in invalidate_reclaim_iterators().
[cai@lca.pw: fix -Wparentheses compilation warning]
Link: http://lkml.kernel.org/r/1564580753-17531-1-git-send-email-cai@lca.pw
Link: http://lkml.kernel.org/r/20190730015729.4406-1-miles.chen@mediatek.com
Fixes: 5ac8fb31ad2e ("mm: memcontrol: convert reclaim iterator to simple css refcounting")
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The constraint from the zpool use of z3fold_destroy_pool() is there are
no outstanding handles to memory (so no active allocations), but it is
possible for there to be outstanding work on either of the two wqs in
the pool.
Calling z3fold_deregister_migration() before the workqueues are drained
means that there can be allocated pages referencing a freed inode,
causing any thread in compaction to be able to trip over the bad pointer
in PageMovable().
Link: http://lkml.kernel.org/r/20190726224810.79660-2-henryburns@google.com
Fixes: 1f862989b04a ("mm/z3fold.c: support page migration")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Jonathan Adams <jwadams@google.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The constraint from the zpool use of z3fold_destroy_pool() is there are
no outstanding handles to memory (so no active allocations), but it is
possible for there to be outstanding work on either of the two wqs in
the pool.
If there is work queued on pool->compact_workqueue when it is called,
z3fold_destroy_pool() will do:
z3fold_destroy_pool()
destroy_workqueue(pool->release_wq)
destroy_workqueue(pool->compact_wq)
drain_workqueue(pool->compact_wq)
do_compact_page(zhdr)
kref_put(&zhdr->refcount)
__release_z3fold_page(zhdr, ...)
queue_work_on(pool->release_wq, &pool->work) *BOOM*
So compact_wq needs to be destroyed before release_wq.
Link: http://lkml.kernel.org/r/20190726224810.79660-1-henryburns@google.com
Fixes: 5d03a6613957 ("mm/z3fold.c: use kref to prevent page free/compact race")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Jonathan Adams <jwadams@google.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
When running syzkaller internally, we ran into the below bug on 4.9.x
kernel:
kernel BUG at mm/huge_memory.c:2124!
invalid opcode: 0000 [#1] SMP KASAN
CPU: 0 PID: 1518 Comm: syz-executor107 Not tainted 4.9.168+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.5.1 01/01/2011
task: ffff880067b34900 task.stack: ffff880068998000
RIP: split_huge_page_to_list+0x8fb/0x1030 mm/huge_memory.c:2124
Call Trace:
split_huge_page include/linux/huge_mm.h:100 [inline]
queue_pages_pte_range+0x7e1/0x1480 mm/mempolicy.c:538
walk_pmd_range mm/pagewalk.c:50 [inline]
walk_pud_range mm/pagewalk.c:90 [inline]
walk_pgd_range mm/pagewalk.c:116 [inline]
__walk_page_range+0x44a/0xdb0 mm/pagewalk.c:208
walk_page_range+0x154/0x370 mm/pagewalk.c:285
queue_pages_range+0x115/0x150 mm/mempolicy.c:694
do_mbind mm/mempolicy.c:1241 [inline]
SYSC_mbind+0x3c3/0x1030 mm/mempolicy.c:1370
SyS_mbind+0x46/0x60 mm/mempolicy.c:1352
do_syscall_64+0x1d2/0x600 arch/x86/entry/common.c:282
entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: c7 80 1c 02 00 e8 26 0a 76 01 <0f> 0b 48 c7 c7 40 46 45 84 e8 4c
RIP [<ffffffff81895d6b>] split_huge_page_to_list+0x8fb/0x1030 mm/huge_memory.c:2124
RSP <ffff88006899f980>
with the below test:
uint64_t r[1] = {0xffffffffffffffff};
int main(void)
{
syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
intptr_t res = 0;
res = syscall(__NR_socket, 0x11, 3, 0x300);
if (res != -1)
r[0] = res;
*(uint32_t*)0x20000040 = 0x10000;
*(uint32_t*)0x20000044 = 1;
*(uint32_t*)0x20000048 = 0xc520;
*(uint32_t*)0x2000004c = 1;
syscall(__NR_setsockopt, r[0], 0x107, 0xd, 0x20000040, 0x10);
syscall(__NR_mmap, 0x20fed000, 0x10000, 0, 0x8811, r[0], 0);
*(uint64_t*)0x20000340 = 2;
syscall(__NR_mbind, 0x20ff9000, 0x4000, 0x4002, 0x20000340, 0x45d4, 3);
return 0;
}
Actually the test does:
mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000
socket(AF_PACKET, SOCK_RAW, 768) = 3
setsockopt(3, SOL_PACKET, PACKET_TX_RING, {block_size=65536, block_nr=1, frame_size=50464, frame_nr=1}, 16) = 0
mmap(0x20fed000, 65536, PROT_NONE, MAP_SHARED|MAP_FIXED|MAP_POPULATE|MAP_DENYWRITE, 3, 0) = 0x20fed000
mbind(..., MPOL_MF_STRICT|MPOL_MF_MOVE) = 0
The setsockopt() would allocate compound pages (16 pages in this test)
for packet tx ring, then the mmap() would call packet_mmap() to map the
pages into the user address space specified by the mmap() call.
When calling mbind(), it would scan the vma to queue the pages for
migration to the new node. It would split any huge page since 4.9
doesn't support THP migration, however, the packet tx ring compound
pages are not THP and even not movable. So, the above bug is triggered.
However, the later kernel is not hit by this issue due to commit
d44d363f6578 ("mm: don't assume anonymous pages have SwapBacked flag"),
which just removes the PageSwapBacked check for a different reason.
But, there is a deeper issue. According to the semantic of mbind(), it
should return -EIO if MPOL_MF_MOVE or MPOL_MF_MOVE_ALL was specified and
MPOL_MF_STRICT was also specified, but the kernel was unable to move all
existing pages in the range. The tx ring of the packet socket is
definitely not movable, however, mbind() returns success for this case.
Although the most socket file associates with non-movable pages, but XDP
may have movable pages from gup. So, it sounds not fine to just check
the underlying file type of vma in vma_migratable().
Change migrate_page_add() to check if the page is movable or not, if it
is unmovable, just return -EIO. But do not abort pte walk immediately,
since there may be pages off LRU temporarily. We should migrate other
pages if MPOL_MF_MOVE* is specified. Set has_unmovable flag if some
paged could not be not moved, then return -EIO for mbind() eventually.
With this change the above test would return -EIO as expected.
[yang.shi@linux.alibaba.com: fix review comments from Vlastimil]
Link: http://lkml.kernel.org/r/1563556862-54056-3-git-send-email-yang.shi@linux.alibaba.com
Link: http://lkml.kernel.org/r/1561162809-59140-3-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
When both MPOL_MF_MOVE* and MPOL_MF_STRICT was specified, mbind() should
try best to migrate misplaced pages, if some of the pages could not be
migrated, then return -EIO.
There are three different sub-cases:
1. vma is not migratable
2. vma is migratable, but there are unmovable pages
3. vma is migratable, pages are movable, but migrate_pages() fails
If #1 happens, kernel would just abort immediately, then return -EIO,
after a7f40cfe3b7a ("mm: mempolicy: make mbind() return -EIO when
MPOL_MF_STRICT is specified").
If #3 happens, kernel would set policy and migrate pages with
best-effort, but won't rollback the migrated pages and reset the policy
back.
Before that commit, they behaves in the same way. It'd better to keep
their behavior consistent. But, rolling back the migrated pages and
resetting the policy back sounds not feasible, so just make #1 behave as
same as #3.
Userspace will know that not everything was successfully migrated (via
-EIO), and can take whatever steps it deems necessary - attempt
rollback, determine which exact page(s) are violating the policy, etc.
Make queue_pages_range() return 1 to indicate there are unmovable pages
or vma is not migratable.
The #2 is not handled correctly in the current kernel, the following
patch will fix it.
[yang.shi@linux.alibaba.com: fix review comments from Vlastimil]
Link: http://lkml.kernel.org/r/1563556862-54056-2-git-send-email-yang.shi@linux.alibaba.com
Link: http://lkml.kernel.org/r/1561162809-59140-2-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
When migrating an anonymous private page to a ZONE_DEVICE private page,
the source page->mapping and page->index fields are copied to the
destination ZONE_DEVICE struct page and the page_mapcount() is
increased. This is so rmap_walk() can be used to unmap and migrate the
page back to system memory.
However, try_to_unmap_one() computes the subpage pointer from a swap pte
which computes an invalid page pointer and a kernel panic results such
as:
BUG: unable to handle page fault for address: ffffea1fffffffc8
Currently, only single pages can be migrated to device private memory so
no subpage computation is needed and it can be set to "page".
[rcampbell@nvidia.com: add comment]
Link: http://lkml.kernel.org/r/20190724232700.23327-4-rcampbell@nvidia.com
Link: http://lkml.kernel.org/r/20190719192955.30462-4-rcampbell@nvidia.com
Fixes: a5430dda8a3a1c ("mm/migrate: support un-addressable ZONE_DEVICE page in migration")
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
When a ZONE_DEVICE private page is freed, the page->mapping field can be
set. If this page is reused as an anonymous page, the previous value
can prevent the page from being inserted into the CPU's anon rmap table.
For example, when migrating a pte_none() page to device memory:
migrate_vma(ops, vma, start, end, src, dst, private)
migrate_vma_collect()
src[] = MIGRATE_PFN_MIGRATE
migrate_vma_prepare()
/* no page to lock or isolate so OK */
migrate_vma_unmap()
/* no page to unmap so OK */
ops->alloc_and_copy()
/* driver allocates ZONE_DEVICE page for dst[] */
migrate_vma_pages()
migrate_vma_insert_page()
page_add_new_anon_rmap()
__page_set_anon_rmap()
/* This check sees the page's stale mapping field */
if (PageAnon(page))
return
/* page->mapping is not updated */
The result is that the migration appears to succeed but a subsequent CPU
fault will be unable to migrate the page back to system memory or worse.
Clear the page->mapping field when freeing the ZONE_DEVICE page so stale
pointer data doesn't affect future page use.
Link: http://lkml.kernel.org/r/20190719192955.30462-3-rcampbell@nvidia.com
Fixes: b7a523109fb5c9d2d6dd ("mm: don't clear ->mapping in hmm_devmem_free")
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jan Kara <jack@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Patch series "mm/hmm: fixes for device private page migration", v3.
Testing the latest linux git tree turned up a few bugs with page
migration to and from ZONE_DEVICE private and anonymous pages.
Hopefully it clarifies how ZONE_DEVICE private struct page uses the same
mapping and index fields from the source anonymous page mapping.
This patch (of 3):
Struct page for ZONE_DEVICE private pages uses the page->mapping and and
page->index fields while the source anonymous pages are migrated to
device private memory. This is so rmap_walk() can find the page when
migrating the ZONE_DEVICE private page back to system memory.
ZONE_DEVICE pmem backed fsdax pages also use the page->mapping and
page->index fields when files are mapped into a process address space.
Add comments to struct page and remove the unused "_zd_pad_1" field to
make this more clear.
Link: http://lkml.kernel.org/r/20190724232700.23327-2-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Commit c78719203fc6 ("KEYS: trusted: allow trusted.ko to initialize w/o a
TPM") allows the trusted module to be loaded even if a TPM is not found, to
avoid module dependency problems.
However, trusted module initialization can still fail if the TPM is
inactive or deactivated. tpm_get_random() returns an error.
This patch removes the call to tpm_get_random() and instead extends the PCR
specified by the user with zeros. The security of this alternative is
equivalent to the previous one, as either option prevents with a PCR update
unsealing and misuse of sealed data by a user space process.
Even if a PCR is extended with zeros, instead of random data, it is still
computationally infeasible to find a value as input for a new PCR extend
operation, to obtain again the PCR value that would allow unsealing.
Cc: stable@vger.kernel.org
Fixes: 240730437deb ("KEYS: trusted: explicitly use tpm_chip structure...")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
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This patch changes the driver/user shared (mmapped) CQ notification
flags field from unsigned 64-bits size to unsigned 32-bits size. This
enables building siw on 32-bit architectures.
This patch changes the siw-abi, but as siw was only just merged in
this merge window cycle, there are no released kernels with the prior
abi. We are making no attempt to be binary compatible with siw user
space libraries prior to the merge of siw into the upstream kernel,
only moving forward with upstream kernels and upstream rdma-core
provided siw libraries are we guaranteeing compatibility.
Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
Link: https://lore.kernel.org/r/20190809151816.13018-1-bmt@zurich.ibm.com
Signed-off-by: Doug Ledford <dledford@redhat.com>
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We need to set the error codes on these paths. Currently the only
possible error code is -EMSGSIZE so that's what the patch uses.
Fixes: 83c2c1fcbd08 ("RDMA/nldev: Allow get counter mode through RDMA netlink")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Link: https://lore.kernel.org/r/20190809101311.GA17867@mwanda
Signed-off-by: Doug Ledford <dledford@redhat.com>
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|
The error handling code doesn't free siw_cpu_info.tx_valid_cpus[0]. The
first iteration through the loop is a no-op so this is sort of an off
by one bug. Also Bernard pointed out that we can remove the NULL
assignment and simplify the code a bit.
Fixes: bdcf26bf9b3a ("rdma/siw: network and RDMA core interface")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Bernard Metzler <bmt@zurich.ibm.com>
Reviewed-by: Bernard Metzler <bmt@zurich.ibm.com>
Link: https://lore.kernel.org/r/20190809140904.GB3552@mwanda
Signed-off-by: Doug Ledford <dledford@redhat.com>
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|
Call to uverbs_close_fd() releases file pointer to 'ev_file' and
mlx5_ib_dev is going to be inaccessible. Cache pointer prior cleaning
resources to solve the KASAN warning below.
BUG: KASAN: use-after-free in devx_async_event_close+0x391/0x480 [mlx5_ib]
Read of size 8 at addr ffff888301e3cec0 by task devx_direct_tes/4631
CPU: 1 PID: 4631 Comm: devx_direct_tes Tainted: G OE 5.3.0-rc1-for-upstream-dbg-2019-07-26_01-19-56-93 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu2 04/01/2014
Call Trace:
dump_stack+0x9a/0xeb
print_address_description+0x1e2/0x400
? devx_async_event_close+0x391/0x480 [mlx5_ib]
__kasan_report+0x15c/0x1df
? devx_async_event_close+0x391/0x480 [mlx5_ib]
kasan_report+0xe/0x20
devx_async_event_close+0x391/0x480 [mlx5_ib]
__fput+0x26a/0x7b0
task_work_run+0x10d/0x180
exit_to_usermode_loop+0x137/0x160
do_syscall_64+0x3c7/0x490
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f5df907d664
Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f
80 00 00 00 00 8b 05 6a cd 20 00 48 63 ff 85 c0 75 13 b8
03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 44 f3 c3 66 90
48 83 ec 18 48 89 7c 24 08 e8
RSP: 002b:00007ffd353cb958 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 000056017a88c348 RCX: 00007f5df907d664
RDX: 00007f5df969d400 RSI: 00007f5de8f1ec90 RDI: 0000000000000006
RBP: 00007f5df9681dc0 R08: 00007f5de8736410 R09: 000056017a9d2dd0
R10: 000000000000000b R11: 0000000000000246 R12: 00007f5de899d7d0
R13: 00007f5df96c4248 R14: 00007f5de8f1ecb0 R15: 000056017ae41308
Allocated by task 4631:
save_stack+0x19/0x80
kasan_kmalloc.constprop.3+0xa0/0xd0
alloc_uobj+0x71/0x230 [ib_uverbs]
alloc_begin_fd_uobject+0x2e/0xc0 [ib_uverbs]
rdma_alloc_begin_uobject+0x96/0x140 [ib_uverbs]
ib_uverbs_run_method+0xdf0/0x1940 [ib_uverbs]
ib_uverbs_cmd_verbs+0x57e/0xdb0 [ib_uverbs]
ib_uverbs_ioctl+0x177/0x260 [ib_uverbs]
do_vfs_ioctl+0x18f/0x1010
ksys_ioctl+0x70/0x80
__x64_sys_ioctl+0x6f/0xb0
do_syscall_64+0x95/0x490
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 4631:
save_stack+0x19/0x80
__kasan_slab_free+0x11d/0x160
slab_free_freelist_hook+0x67/0x1a0
kfree+0xb9/0x2a0
uverbs_close_fd+0x118/0x1c0 [ib_uverbs]
devx_async_event_close+0x28a/0x480 [mlx5_ib]
__fput+0x26a/0x7b0
task_work_run+0x10d/0x180
exit_to_usermode_loop+0x137/0x160
do_syscall_64+0x3c7/0x490
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff888301e3cda8
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 280 bytes inside of 512-byte region
[ffff888301e3cda8, ffff888301e3cfa8)
The buggy address belongs to the page:
page:ffffea000c078e00 refcount:1 mapcount:0
mapping:ffff888352811300 index:0x0 compound_mapcount: 0
flags: 0x2fffff80010200(slab|head)
raw: 002fffff80010200 ffffea000d152608 ffffea000c077808 ffff888352811300
raw: 0000000000000000 0000000000250025 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888301e3cd80: fc fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb
ffff888301e3ce00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888301e3ce80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888301e3cf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888301e3cf80: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc
Disabling lock debugging due to kernel taint
Cc: <stable@vger.kernel.org> # 5.2
Fixes: 759738537142 ("IB/mlx5: Enable subscription for device events over DEVX")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Link: https://lore.kernel.org/r/20190808081538.28772-1-leon@kernel.org
Signed-off-by: Doug Ledford <dledford@redhat.com>
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|
|
|
A compilation -Wimplicit-fallthrough warning was enabled by commit
a035d552a93b ("Makefile: Globally enable fall-through warning")
Even though clang 10.0.0 does not currently support this warning without
a patch, clang currently does not support a value for this option.
Link: https://bugs.llvm.org/show_bug.cgi?id=39382
The gcc default for this warning is 3 so removing the =3 has no effect
for gcc and enables the warning for patched versions of clang.
Also remove the =3 from an existing use in a parisc Makefile:
arch/parisc/math-emu/Makefile
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-and-tested-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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|
All the way back to introducing dma_common_mmap we've defaulted to mark
the pages as uncached. But this is wrong for DMA coherent devices.
Later on DMA_ATTR_WRITE_COMBINE also got incorrect treatment as that
flag is only treated special on the alloc side for non-coherent devices.
Introduce a new dma_pgprot helper that deals with the check for coherent
devices so that only the remapping cases ever reach arch_dma_mmap_pgprot
and we thus ensure no aliasing of page attributes happens, which makes
the powerpc version of arch_dma_mmap_pgprot obsolete and simplifies the
remaining ones.
Note that this means arch_dma_mmap_pgprot is a bit misnamed now, but
we'll phase it out soon.
Fixes: 64ccc9c033c6 ("common: dma-mapping: add support for generic dma_mmap_* calls")
Reported-by: Shawn Anastasio <shawn@anastas.io>
Reported-by: Gavin Li <git@thegavinli.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> # arm64
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The dma required_mask needs to reflect the actual addressing capabilities
needed to handle the whole system RAM. When truncated down to the bus
addressing capabilities dma_addressing_limited() will incorrectly signal
no limitations for devices which are restricted by the bus_dma_mask.
Fixes: b4ebe6063204 (dma-direct: implement complete bus_dma_mask handling)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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The new DMA_ATTR_NO_KERNEL_MAPPING needs to actually assign
a dma_addr to work. Also skip it if the architecture needs
forced decryption handling, as that needs a kernel virtual
address.
Fixes: d98849aff879 (dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
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Mark switch cases where we are expecting to fall through.
Fix the following warnings (Building: arm-ep93xx_defconfig arm):
arch/arm/mach-ep93xx/crunch.c: In function 'crunch_do':
arch/arm/mach-ep93xx/crunch.c:46:3: warning: this statement may
fall through [-Wimplicit-fallthrough=]
memset(crunch_state, 0, sizeof(*crunch_state));
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/arm/mach-ep93xx/crunch.c:53:2: note: here
case THREAD_NOTIFY_EXIT:
^~~~
Notice that, in this particular case, the code comment is
modified in accordance with what GCC is expecting to find.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
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Mark switch cases where we are expecting to fall through.
Fix the following warnings (Building: rpc_defconfig arm):
drivers/scsi/arm/fas216.c: In function ‘fas216_disconnect_intr’:
drivers/scsi/arm/fas216.c:913:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (fas216_get_last_msg(info, info->scsi.msgin_fifo) == ABORT) {
^
drivers/scsi/arm/fas216.c:919:2: note: here
default: /* huh? */
^~~~~~~
drivers/scsi/arm/fas216.c: In function ‘fas216_kick’:
drivers/scsi/arm/fas216.c:1959:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
fas216_allocate_tag(info, SCpnt);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/arm/fas216.c:1960:2: note: here
case TYPE_OTHER:
^~~~
drivers/scsi/arm/fas216.c: In function ‘fas216_busservice_intr’:
drivers/scsi/arm/fas216.c:1413:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
fas216_stoptransfer(info);
^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/arm/fas216.c:1414:2: note: here
case STATE(STAT_STATUS, PHASE_SELSTEPS):/* Sel w/ steps -> Status */
^~~~
drivers/scsi/arm/fas216.c:1424:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
fas216_stoptransfer(info);
^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/arm/fas216.c:1425:2: note: here
case STATE(STAT_MESGIN, PHASE_COMMAND): /* Command -> Message In */
^~~~
drivers/scsi/arm/fas216.c: In function ‘fas216_funcdone_intr’:
drivers/scsi/arm/fas216.c:1573:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if ((stat & STAT_BUSMASK) == STAT_MESGIN) {
^
drivers/scsi/arm/fas216.c:1579:2: note: here
default:
^~~~~~~
drivers/scsi/arm/fas216.c: In function ‘fas216_handlesync’:
drivers/scsi/arm/fas216.c:605:20: warning: this statement may fall through [-Wimplicit-fallthrough=]
info->scsi.phase = PHASE_MSGOUT_EXPECT;
~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
drivers/scsi/arm/fas216.c:607:2: note: here
case async:
^~~~
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
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Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings (Building: db1xxx_defconfig mips):
drivers/pcmcia/db1xxx_ss.c:257:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/pcmcia/db1xxx_ss.c:269:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
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Mark switch cases where we are expecting to fall through.
This patch fixes the following warning (Building: omap1_defconfig arm):
drivers/watchdog/wdt285.c:170:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/watchdog/ar7_wdt.c:237:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/video/fbdev/omap/omapfb_main.c:449:23: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/video/fbdev/omap/omapfb_main.c:1549:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/video/fbdev/omap/omapfb_main.c:1547:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/video/fbdev/omap/omapfb_main.c:1545:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/video/fbdev/omap/omapfb_main.c:1543:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/video/fbdev/omap/omapfb_main.c:1540:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/video/fbdev/omap/omapfb_main.c:1538:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
drivers/video/fbdev/omap/omapfb_main.c:1535:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
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Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings (Building: sparc64):
drivers/watchdog/riowd.c: In function ‘riowd_ioctl’:
drivers/watchdog/riowd.c:136:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
riowd_writereg(p, riowd_timeout, WDTO_INDEX);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/watchdog/riowd.c:139:2: note: here
case WDIOC_GETTIMEOUT:
^~~~
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
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Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings (Building: s390):
drivers/s390/net/ctcm_fsms.c: In function ‘ctcmpc_chx_attnbusy’:
drivers/s390/net/ctcm_fsms.c:1703:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (grp->changed_side == 1) {
^
drivers/s390/net/ctcm_fsms.c:1707:2: note: here
case MPCG_STATE_XID0IOWAIX:
^~~~
drivers/s390/net/ctcm_mpc.c: In function ‘ctc_mpc_alloc_channel’:
drivers/s390/net/ctcm_mpc.c:358:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (callback)
^
drivers/s390/net/ctcm_mpc.c:360:2: note: here
case MPCG_STATE_XID0IOWAIT:
^~~~
drivers/s390/net/ctcm_mpc.c: In function ‘mpc_action_timeout’:
drivers/s390/net/ctcm_mpc.c:1469:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if ((fsm_getstate(rch->fsm) == CH_XID0_PENDING) &&
^
drivers/s390/net/ctcm_mpc.c:1472:2: note: here
default:
^~~~~~~
drivers/s390/net/ctcm_mpc.c: In function ‘mpc_send_qllc_discontact’:
drivers/s390/net/ctcm_mpc.c:2087:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (grp->estconnfunc) {
^
drivers/s390/net/ctcm_mpc.c:2092:2: note: here
case MPCG_STATE_FLOWC:
^~~~
drivers/s390/net/qeth_l2_main.c: In function ‘qeth_l2_process_inbound_buffer’:
drivers/s390/net/qeth_l2_main.c:328:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (IS_OSN(card)) {
^
drivers/s390/net/qeth_l2_main.c:337:3: note: here
default:
^~~~~~~
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
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|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warning (Building: arm):
drivers/crypto/ux500/cryp/cryp.c: In function ‘cryp_save_device_context’:
drivers/crypto/ux500/cryp/cryp.c:316:16: warning: this statement may fall through [-Wimplicit-fallthrough=]
ctx->key_4_r = readl_relaxed(&src_reg->key_4_r);
drivers/crypto/ux500/cryp/cryp.c:318:2: note: here
case CRYP_KEY_SIZE_192:
^~~~
drivers/crypto/ux500/cryp/cryp.c:320:16: warning: this statement may fall through [-Wimplicit-fallthrough=]
ctx->key_3_r = readl_relaxed(&src_reg->key_3_r);
drivers/crypto/ux500/cryp/cryp.c:322:2: note: here
case CRYP_KEY_SIZE_128:
^~~~
drivers/crypto/ux500/cryp/cryp.c:324:16: warning: this statement may fall through [-Wimplicit-fallthrough=]
ctx->key_2_r = readl_relaxed(&src_reg->key_2_r);
drivers/crypto/ux500/cryp/cryp.c:326:2: note: here
default:
^~~~~~~
In file included from ./include/linux/io.h:13:0,
from drivers/crypto/ux500/cryp/cryp_p.h:14,
from drivers/crypto/ux500/cryp/cryp.c:15:
drivers/crypto/ux500/cryp/cryp.c: In function ‘cryp_restore_device_context’:
./arch/arm/include/asm/io.h:92:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
#define __raw_writel __raw_writel
^
./arch/arm/include/asm/io.h:299:29: note: in expansion of macro ‘__raw_writel’
#define writel_relaxed(v,c) __raw_writel((__force u32) cpu_to_le32(v),c)
^~~~~~~~~~~~
drivers/crypto/ux500/cryp/cryp.c:363:3: note: in expansion of macro ‘writel_relaxed’
writel_relaxed(ctx->key_4_r, ®->key_4_r);
^~~~~~~~~~~~~~
drivers/crypto/ux500/cryp/cryp.c:365:2: note: here
case CRYP_KEY_SIZE_192:
^~~~
In file included from ./include/linux/io.h:13:0,
from drivers/crypto/ux500/cryp/cryp_p.h:14,
from drivers/crypto/ux500/cryp/cryp.c:15:
./arch/arm/include/asm/io.h:92:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
#define __raw_writel __raw_writel
^
./arch/arm/include/asm/io.h:299:29: note: in expansion of macro ‘__raw_writel’
#define writel_relaxed(v,c) __raw_writel((__force u32) cpu_to_le32(v),c)
^~~~~~~~~~~~
drivers/crypto/ux500/cryp/cryp.c:367:3: note: in expansion of macro ‘writel_relaxed’
writel_relaxed(ctx->key_3_r, ®->key_3_r);
^~~~~~~~~~~~~~
drivers/crypto/ux500/cryp/cryp.c:369:2: note: here
case CRYP_KEY_SIZE_128:
^~~~
In file included from ./include/linux/io.h:13:0,
from drivers/crypto/ux500/cryp/cryp_p.h:14,
from drivers/crypto/ux500/cryp/cryp.c:15:
./arch/arm/include/asm/io.h:92:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
#define __raw_writel __raw_writel
^
./arch/arm/include/asm/io.h:299:29: note: in expansion of macro ‘__raw_writel’
#define writel_relaxed(v,c) __raw_writel((__force u32) cpu_to_le32(v),c)
^~~~~~~~~~~~
drivers/crypto/ux500/cryp/cryp.c:371:3: note: in expansion of macro ‘writel_relaxed’
writel_relaxed(ctx->key_2_r, ®->key_2_r);
^~~~~~~~~~~~~~
drivers/crypto/ux500/cryp/cryp.c:373:2: note: here
default:
^~~~~~~
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warning (Building: arm):
drivers/watchdog/wdt977.c: In function ‘wdt977_ioctl’:
LD [M] drivers/media/platform/vicodec/vicodec.o
drivers/watchdog/wdt977.c:400:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
wdt977_keepalive();
^~~~~~~~~~~~~~~~~~
drivers/watchdog/wdt977.c:403:2: note: here
case WDIOC_GETTIMEOUT:
^~~~
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warning (Building: i386):
drivers/watchdog/scx200_wdt.c: In function ‘scx200_wdt_ioctl’:
drivers/watchdog/scx200_wdt.c:188:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
scx200_wdt_ping();
^~~~~~~~~~~~~~~~~
drivers/watchdog/scx200_wdt.c:189:2: note: here
case WDIOC_GETTIMEOUT:
^~~~
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings:
drivers/watchdog/ar7_wdt.c: warning: this statement may fall
through [-Wimplicit-fallthrough=]: => 237:3
drivers/watchdog/pcwd.c: warning: this statement may fall
through [-Wimplicit-fallthrough=]: => 653:3
drivers/watchdog/sb_wdog.c: warning: this statement may fall
through [-Wimplicit-fallthrough=]: => 204:3
drivers/watchdog/wdt.c: warning: this statement may fall
through [-Wimplicit-fallthrough=]: => 391:3
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warning:
arch/arm/kernel/signal.c: In function 'do_signal':
arch/arm/kernel/signal.c:598:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
restart -= 2;
~~~~~~~~^~~~
arch/arm/kernel/signal.c:599:3: note: here
case -ERESTARTNOHAND:
^~~~
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings:
drivers/mfd/omap-usb-host.c: In function 'usbhs_runtime_resume':
drivers/mfd/omap-usb-host.c:303:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (!IS_ERR(omap->hsic480m_clk[i])) {
^
drivers/mfd/omap-usb-host.c:313:3: note: here
case OMAP_EHCI_PORT_MODE_TLL:
^~~~
drivers/mfd/omap-usb-host.c: In function 'usbhs_runtime_suspend':
drivers/mfd/omap-usb-host.c:345:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (!IS_ERR(omap->hsic480m_clk[i]))
^
drivers/mfd/omap-usb-host.c:349:3: note: here
case OMAP_EHCI_PORT_MODE_TLL:
^~~~
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings:
drivers/mfd/db8500-prcmu.c: In function 'dsiclk_rate':
drivers/mfd/db8500-prcmu.c:1592:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
div *= 2;
~~~~^~~~
drivers/mfd/db8500-prcmu.c:1593:2: note: here
case PRCM_DSI_PLLOUT_SEL_PHI_2:
^~~~
drivers/mfd/db8500-prcmu.c:1594:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
div *= 2;
~~~~^~~~
drivers/mfd/db8500-prcmu.c:1595:2: note: here
case PRCM_DSI_PLLOUT_SEL_PHI:
^~~~
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings:
arch/arm/plat-omap/dma.c: In function 'omap_set_dma_src_burst_mode':
arch/arm/plat-omap/dma.c:384:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (dma_omap2plus()) {
^
arch/arm/plat-omap/dma.c:393:2: note: here
case OMAP_DMA_DATA_BURST_16:
^~~~
arch/arm/plat-omap/dma.c:394:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (dma_omap2plus()) {
^
arch/arm/plat-omap/dma.c:402:2: note: here
default:
^~~~~~~
arch/arm/plat-omap/dma.c: In function 'omap_set_dma_dest_burst_mode':
arch/arm/plat-omap/dma.c:473:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (dma_omap2plus()) {
^
arch/arm/plat-omap/dma.c:481:2: note: here
default:
^~~~~~~
Notice that, in this particular case, the code comment is
modified in accordance with what GCC is expecting to find.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings:
arch/arm/mm/alignment.c: In function 'thumb2arm':
arch/arm/mm/alignment.c:688:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if ((tinstr & (3 << 9)) == 0x0400) {
^
arch/arm/mm/alignment.c:700:2: note: here
default:
^~~~~~~
arch/arm/mm/alignment.c: In function 'do_alignment_t32_to_handler':
arch/arm/mm/alignment.c:753:15: warning: this statement may fall through [-Wimplicit-fallthrough=]
poffset->un = (tinst2 & 0xff) << 2;
~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
arch/arm/mm/alignment.c:754:2: note: here
case 0xe940:
^~~~
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warning:
arch/arm/mach-tegra/reset.c: In function 'tegra_cpu_reset_handler_enable':
arch/arm/mach-tegra/reset.c:72:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
tegra_cpu_reset_handler_set(reset_address);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/arm/mach-tegra/reset.c:74:2: note: here
case 0:
^~~~
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Mark switch cases where we are expecting to fall through.
This patch fixes the following warnings:
arch/arm/kernel/hw_breakpoint.c: In function 'hw_breakpoint_arch_parse':
arch/arm/kernel/hw_breakpoint.c:609:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
^
arch/arm/kernel/hw_breakpoint.c:611:2: note: here
case 3:
^~~~
arch/arm/kernel/hw_breakpoint.c:613:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
^
arch/arm/kernel/hw_breakpoint.c:615:2: note: here
default:
^~~~~~~
arch/arm/kernel/hw_breakpoint.c: In function 'arch_build_bp_info':
arch/arm/kernel/hw_breakpoint.c:544:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if ((hw->ctrl.type != ARM_BREAKPOINT_EXECUTE)
^
arch/arm/kernel/hw_breakpoint.c:547:2: note: here
default:
^~~~~~~
In file included from include/linux/kernel.h:11,
from include/linux/list.h:9,
from include/linux/preempt.h:11,
from include/linux/hardirq.h:5,
from arch/arm/kernel/hw_breakpoint.c:16:
arch/arm/kernel/hw_breakpoint.c: In function 'hw_breakpoint_pending':
include/linux/compiler.h:78:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
# define unlikely(x) __builtin_expect(!!(x), 0)
^~~~~~~~~~~~~~~~~~~~~~~~~~
include/asm-generic/bug.h:136:2: note: in expansion of macro 'unlikely'
unlikely(__ret_warn_on); \
^~~~~~~~
arch/arm/kernel/hw_breakpoint.c:863:3: note: in expansion of macro 'WARN'
WARN(1, "Asynchronous watchpoint exception taken. Debugging results may be unreliable\n");
^~~~
arch/arm/kernel/hw_breakpoint.c:864:2: note: here
case ARM_ENTRY_SYNC_WATCHPOINT:
^~~~
arch/arm/kernel/hw_breakpoint.c: In function 'core_has_os_save_restore':
arch/arm/kernel/hw_breakpoint.c:910:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (oslsr & ARM_OSLSR_OSLM0)
^
arch/arm/kernel/hw_breakpoint.c:912:2: note: here
default:
^~~~~~~
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
|
|
Currently, attempts to shutdown and re-enable a device-dax instance
trigger:
Missing reference count teardown definition
WARNING: CPU: 37 PID: 1608 at mm/memremap.c:211 devm_memremap_pages+0x234/0x850
[..]
RIP: 0010:devm_memremap_pages+0x234/0x850
[..]
Call Trace:
dev_dax_probe+0x66/0x190 [device_dax]
really_probe+0xef/0x390
driver_probe_device+0xb4/0x100
device_driver_attach+0x4f/0x60
Given that the setup path initializes pgmap->ref, arrange for it to be
also torn down so devm_memremap_pages() is ready to be called again and
not be mistaken for the 3rd-party per-cpu-ref case.
Fixes: 24917f6b1041 ("memremap: provide an optional internal refcount in struct dev_pagemap")
Reported-by: Fan Du <fan.du@intel.com>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/156530042781.2068700.8733813683117819799.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
|
|
Objtool reports:
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool: .altinstr_replacement+0x36: redundant UACCESS disable
__copy_from_user() already does both STAC and CLAC, so the
user_access_end() in its error path adds an extra unnecessary CLAC.
Fixes: 0b2c8f8b6b0c ("i915: fix missing user_access_end() in page fault exception case")
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://github.com/ClangBuiltLinux/linux/issues/617
Link: https://lkml.kernel.org/r/51a4155c5bc2ca847a9cbe85c1c11918bb193141.1564086017.git.jpoimboe@redhat.com
|
|
Since commit ff9b45c55b26 ("kbuild: modpost: read modules.order instead
of $(MODVERDIR)/*.mod"), a module is no longer built in the following
pattern:
[Makefile]
subdir-y := some-module
[some-module/Makefile]
obj-m := some-module.o
You cannot write Makefile this way in upstream because modules.order is
not correctly generated. subdir-y is used to descend to a sub-directory
that builds tools, device trees, etc.
For external modules, the modules order does not matter. So, the
Makefile above was known to work.
I believe the Makefile should be re-written as follows:
[Makefile]
obj-m := some-module/
[some-module/Makefile]
obj-m := some-module.o
However, people will have no idea if their Makefile suddenly stops
working. In fact, I received questions from multiple people.
Show a warning for a while if obj-m is specified in a Makefile visited
by subdir-y or subdir-m.
I touched the %/ rule to avoid false-positive warnings for the single
target.
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Tom Stonecypher <thomas.edwardx.stonecypher@intel.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
|
|
The modules.order files in directories visited by the chain of obj-y
or obj-m are merged to the upper-level ones, and become parts of the
top-level modules.order. On the other hand, there is no need to
generate modules.order in directories visited by subdir-y or subdir-m
since they would become orphan anyway.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
|
|
The current implementation of need-builtin is false-positive,
for example, in the following Makefile:
obj-m := foo/
obj-y := foo/bar/
..., where foo/built-in.a is not required.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
|
|
I removed the single target %.ko in commit ff9b45c55b26 ("kbuild:
modpost: read modules.order instead of $(MODVERDIR)/*.mod") because
the modpost stage does not work reliably. For instance, the module
dependency, modversion, etc. do not work if we lack symbol information
from the other modules.
Yet, some people still want to build only one module in their interest,
and it may be still useful if it is used within those limitations.
Fixes: ff9b45c55b26 ("kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod")
Reported-by: Don Brace <don.brace@microsemi.com>
Reported-by: Arend Van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
|
Mel Gorman
Andrea Arcangeli
Qian Cai
NeilBrown
Roman Gushchin
Isaac J. Manjarres
Catalin Marinas
Kuppuswamy Sathyanarayanan
Miles Chen
Henry Burns
Yang Shi
Ralph Campbell
Roberto Sassu
Bernard Metzler
Dan Carpenter
Yishai Hadas
Linus Torvalds
Joe Perches
Christoph Hellwig
Lucas Stach
Gustavo A. R. Silva
Dan Williams
Josh Poimboeuf
Masahiro Yamada