trace_parser_put() simply frees the allocated parser buffer. But it does not
reset the pointer that was freed. This means that if trace_parser_put() is
called on the same parser more than once, it will corrupt the allocation
system. Setting parser->buffer to NULL after free allows it to be called
more than once without any ill effect.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since reading the set_graph_functions uses seq functions, which sets the
file->private_data pointer to a seq_file descriptor. On writes the
ftrace_graph_data descriptor is set to file->private_data. But if the file
is opened for RDWR, the ftrace_graph_write() will incorrectly use the
file->private_data descriptor instead of
((struct seq_file *)file->private_data)->private pointer, and this can crash
the kernel.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When the set_graph_function or set_graph_notrace contains no records, a
banner is displayed of either "#### all functions enabled ####" or
"#### all functions disabled ####" respectively. To tell the seq operations
to do this, (void *)1 is passed as a return value. Instead of using a
hardcoded meaningless variable, define it as a macro.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This is a micro-optimization, but as it has to deal with a fast path of the
function tracer, these optimizations can be noticed.
The ftrace_lookup_ip() returns true if the given ip is found in the hash. If
it's not found or the hash is NULL, it returns false. But there's some cases
that a NULL hash is a true, and the ftrace_hash_empty() is tested before
calling ftrace_lookup_ip() in those cases. But as ftrace_lookup_ip() tests
that first, that adds a few extra unneeded instructions in those cases.
A new static "always_inlined" function is created that does not perform the
hash empty test. This most only be used by callers that do the check first
anyway, as an empty or NULL hash could cause a crash if a lookup is
performed on it.
Also add kernel doc for the ftrace_lookup_ip() main function.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Replace the couple of use cases that has small logic to produce the ftrace
function key id with a helper function. No need for duplicate code.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Use ftrace_hash instead of a static array of a fixed size. This is
useful when a graph filter pattern matches to a large number of
functions. Now hash lookup is done with preemption disabled to protect
from the hash being changed/freed.
Link: http://lkml.kernel.org/r/20170120024447.26097-3-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
It will be used when checking graph filter hashes later.
Link: http://lkml.kernel.org/r/20170120024447.26097-2-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
[ Moved ftrace_hash dec and functions outside of FUNCTION_GRAPH define ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The __ftrace_hash_move() is to allocates properly-sized hash and move
entries in the src ftrace_hash. It will be used to set function graph
filters which has nothing to do with the dyn_ftrace records.
Link: http://lkml.kernel.org/r/20170120024447.26097-1-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The unlikely/likely branch profiler now gets called even if the if statement
is a constant (always goes in one direction without a compare). Add a value
to denote this in the likely/unlikely tracer as well.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Now that constants are traced, it is useful to see the number of constants
that are traced in the likely/unlikely profiler in order to know if they
should be ignored or not.
The likely/unlikely will display a number after the "correct" number if a
"constant" count exists.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When running the likely/unlikely profiler, one of the results did not look
accurate. It noted that the unlikely() in link_path_walk() was 100%
incorrect. When I added a trace_printk() to see what was happening there, it
became 80% correct! Looking deeper into what whas happening, I found that
gcc split that if statement into two paths. One where the if statement
became a constant, the other path a variable. The other path had the if
statement always hit (making the unlikely there, always false), but since
the #define unlikely() has:
#define unlikely() (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
Where constants are ignored by the branch profiler, the "constant" path
made by the compiler was ignored, even though it was hit 80% of the time.
By just passing the constant value to the __branch_check__() function and
tracing it out of line (as always correct, as likely/unlikely isn't a factor
for constants), then we get back the accurate readings of branches that were
optimized by gcc causing part of the execution to become constant.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Previously, `create_trace_uprobe` found the *first* occurence
of the ':' character when parsing `PATH:OFFSET` for a uprobe.
However, if the path contains a ':' character, then the function
would parse the path incorrectly. Even worse, if the path does not
exist, the subsequent call to `kern_path()` would set `ret` to
`ENOENT`, leading to very cryptic errno values in user space.
The fix is to find the *last* occurence of ':'.
How to repro:: The write fails with "No such file or directory", suggesting
incorrectly that the `uprobe_events` file does not exist.
$ mkdir testing && cd testing
$ cp /bin/bash .
$ cp /bin/bash ./bash:with:colon
$ echo "p:uprobes/p__root_testing_bash_0x6 /root/testing/bash:0x6" > /sys/kernel/debug/tracing/uprobe_events # this works
$ echo "p:uprobes/p__root_testing_bash_with_colon_0x6 /root/testing/bash:with:colon:0x6" >> /sys/kernel/debug/tracing/uprobe_events # this doesn't
-bash: echo: write error: No such file or directory
With the patch:
$ echo "p:uprobes/p__root_testing_bash_0x6 /root/testing/bash:0x6" > /sys/kernel/debug/tracing/uprobe_events # this still works
$ echo "p:uprobes/p__root_testing_bash_with_colon_0x6 /root/testing/bash:with:colon:0x6" >> /sys/kernel/debug/tracing/uprobe_events # this works now too!
$ cat /sys/kernel/debug/tracing/uprobe_events
p:uprobes/p__root_testing_bash_0x6 /root/testing/bash:0x0000000000000006
p:uprobes/p__root_testing_bash_with_colon_0x6 /root/testing/bash:with:colon:0x0000000000000006
Link: http://lkml.kernel.org/r/20170113165834.4081016-1-kennyyu@fb.com
Signed-off-by: Kenny Yu <kennyyu@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull DAX updates from Dan Williams:
"The completion of Jan's DAX work for 4.10.
As I mentioned in the libnvdimm-for-4.10 pull request, these are some
final fixes for the DAX dirty-cacheline-tracking invalidation work
that was merged through the -mm, ext4, and xfs trees in -rc1. These
patches were prepared prior to the merge window, but we waited for
4.10-rc1 to have a stable merge base after all the prerequisites were
merged.
Quoting Jan on the overall changes in these patches:
"So I'd like all these 6 patches to go for rc2. The first three
patches fix invalidation of exceptional DAX entries (a bug which
is there for a long time) - without these patches data loss can
occur on power failure even though user called fsync(2). The other
three patches change locking of DAX faults so that ->iomap_begin()
is called in a more relaxed locking context and we are safe to
start a transaction there for ext4"
These have received a build success notification from the kbuild
robot, and pass the latest libnvdimm unit tests. There have not been
any -next releases since -rc1, so they have not appeared there"
* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
ext4: Simplify DAX fault path
dax: Call ->iomap_begin without entry lock during dax fault
dax: Finish fault completely when loading holes
dax: Avoid page invalidation races and unnecessary radix tree traversals
mm: Invalidate DAX radix tree entries only if appropriate
ext2: Return BH_New buffers for zeroed blocks
- A merge error on my part broke the DocBook build. I've requisitioned
one of tglx's frozen sharks for appropriate disciplinary action and
resolved to be more careful about testing the DocBook stuff as long as
it's still around.
- Fix an error in unaligned-memory-access.txt
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Merge tag 'docs-4.10-rc1-fix' of git://git.lwn.net/linux
Pull documentation fixes from Jonathan Corbet:
"Two small fixes:
- A merge error on my part broke the DocBook build. I've
requisitioned one of tglx's frozen sharks for appropriate
disciplinary action and resolved to be more careful about testing
the DocBook stuff as long as it's still around.
- Fix an error in unaligned-memory-access.txt"
* tag 'docs-4.10-rc1-fix' of git://git.lwn.net/linux:
Documentation/unaligned-memory-access.txt: fix incorrect comparison operator
docs: Fix build failure
Pull crypto fix from Herbert Xu:
"This fixes a boot failure on some platforms when crypto self test is
enabled along with the new acomp interface"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: testmgr - Use heap buffer for acomp test input
mm/filemap.c: In function 'clear_bit_unlock_is_negative_byte':
mm/filemap.c:933:9: error: too few arguments to function 'test_bit'
return test_bit(PG_waiters);
^~~~~~~~
Fixes: b91e1302ad ('mm: optimize PageWaiters bit use for unlock_page()')
Signed-off-by: Olof Johansson <olof@lixom.net>
Brown-paper-bag-by: Linus Torvalds <dummy@duh.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In commit 6290602709 ("mm: add PageWaiters indicating tasks are
waiting for a page bit") Nick Piggin made our page locking no longer
unconditionally touch the hashed page waitqueue, which not only helps
performance in general, but is particularly helpful on NUMA machines
where the hashed wait queues can bounce around a lot.
However, the "clear lock bit atomically and then test the waiters bit"
sequence turns out to be much more expensive than it needs to be,
because you get a nasty stall when trying to access the same word that
just got updated atomically.
On architectures where locking is done with LL/SC, this would be trivial
to fix with a new primitive that clears one bit and tests another
atomically, but that ends up not working on x86, where the only atomic
operations that return the result end up being cmpxchg and xadd. The
atomic bit operations return the old value of the same bit we changed,
not the value of an unrelated bit.
On x86, we could put the lock bit in the high bit of the byte, and use
"xadd" with that bit (where the overflow ends up not touching other
bits), and look at the other bits of the result. However, an even
simpler model is to just use a regular atomic "and" to clear the lock
bit, and then the sign bit in eflags will indicate the resulting state
of the unrelated bit #7.
So by moving the PageWaiters bit up to bit #7, we can atomically clear
the lock bit and test the waiters bit on x86 too. And architectures
with LL/SC (which is all the usual RISC suspects), the particular bit
doesn't matter, so they are fine with this approach too.
This avoids the extra access to the same atomic word, and thus avoids
the costly stall at page unlock time.
The only downside is that the interface ends up being a bit odd and
specialized: clear a bit in a byte, and test the sign bit. Nick doesn't
love the resulting name of the new primitive, but I'd rather make the
name be descriptive and very clear about the limitation imposed by
trying to work across all relevant architectures than make it be some
generic thing that doesn't make the odd semantics explicit.
So this introduces the new architecture primitive
clear_bit_unlock_is_negative_byte();
and adds the trivial implementation for x86. We have a generic
non-optimized fallback (that just does a "clear_bit()"+"test_bit(7)"
combination) which can be overridden by any architecture that can do
better. According to Nick, Power has the same hickup x86 has, for
example, but some other architectures may not even care.
All these optimizations mean that my page locking stress-test (which is
just executing a lot of small short-lived shell scripts: "make test" in
the git source tree) no longer makes our page locking look horribly bad.
Before all these optimizations, just the unlock_page() costs were just
over 3% of all CPU overhead on "make test". After this, it's down to
0.66%, so just a quarter of the cost it used to be.
(The difference on NUMA is bigger, but there this micro-optimization is
likely less noticeable, since the big issue on NUMA was not the accesses
to 'struct page', but the waitqueue accesses that were already removed
by Nick's earlier commit).
Acked-by: Nick Piggin <npiggin@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull crypto fix from Herbert Xu:
"This fixes a hash corruption bug in the marvell driver"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: marvell - Copy IVDIG before launching partial DMA ahash requests
Pull networking fixes from David Miller:
1) Various ipvlan fixes from Eric Dumazet and Mahesh Bandewar.
The most important is to not assume the packet is RX just because
the destination address matches that of the device. Such an
assumption causes problems when an interface is put into loopback
mode.
2) If we retry when creating a new tc entry (because we dropped the
RTNL mutex in order to load a module, for example) we end up with
-EAGAIN and then loop trying to replay the request. But we didn't
reset some state when looping back to the top like this, and if
another thread meanwhile inserted the same tc entry we were trying
to, we re-link it creating an enless loop in the tc chain. Fix from
Daniel Borkmann.
3) There are two different WRITE bits in the MDIO address register for
the stmmac chip, depending upon the chip variant. Due to a bug we
could set them both, fix from Hock Leong Kweh.
4) Fix mlx4 bug in XDP_TX handling, from Tariq Toukan.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
net: stmmac: fix incorrect bit set in gmac4 mdio addr register
r8169: add support for RTL8168 series add-on card.
net: xdp: remove unused bfp_warn_invalid_xdp_buffer()
openvswitch: upcall: Fix vlan handling.
ipv4: Namespaceify tcp_tw_reuse knob
net: korina: Fix NAPI versus resources freeing
net, sched: fix soft lockup in tc_classify
net/mlx4_en: Fix user prio field in XDP forward
tipc: don't send FIN message from connectionless socket
ipvlan: fix multicast processing
ipvlan: fix various issues in ipvlan_process_multicast()
In the actual implementation ether_addr_equal function tests for equality to 0
when returning. It seems in commit 0d74c4 it is somehow overlooked to change
this operator to reflect the actual function.
Signed-off-by: Cihangir Akturk <cakturk@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The 80211.tmpl DocBook file was removed in commit 819bf59376 ("docs-rst:
sphinxify 802.11 documentation"), but the 80211.xml target was re-added to
the Makefile by commit 7ddedebb03 ("ALSA: doc: ReSTize
writing-an-alsa-driver document"), leading to a failure when building the
documentation:
*** No rule to make target 'Documentation/DocBook/80211.xml', needed by
'Documentation/DocBook/80211.aux.xml'.
cc: stable@vger.kernel.org
Signed-off-by: John Brooks <john@fastquake.com>
Mea-culpa-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Fixing the gmac4 mdio write access to use MII_GMAC4_WRITE only instead of
OR together with MII_WRITE.
Signed-off-by: Kweh, Hock Leong <hock.leong.kweh@intel.com>
Acked-By: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This chip is the same as RTL8168, but its device id is 0x8161.
Signed-off-by: Chun-Hao Lin <hau@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit 73b62bd085 ("virtio-net:
remove the warning before XDP linearizing"), there's no users for
bpf_warn_invalid_xdp_buffer(), so remove it. This is a revert for
commit f23bc46c30.
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Networking stack accelerate vlan tag handling by
keeping topmost vlan header in skb. This works as
long as packet remains in OVS datapath. But during
OVS upcall vlan header is pushed on to the packet.
When such packet is sent back to OVS datapath, core
networking stack might not handle it correctly. Following
patch avoids this issue by accelerating the vlan tag
during flow key extract. This simplifies datapath by
bringing uniform packet processing for packets from
all code paths.
Fixes: 5108bbaddc ("openvswitch: add processing of L3 packets").
CC: Jarno Rajahalme <jarno@ovn.org>
CC: Jiri Benc <jbenc@redhat.com>
Signed-off-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Different namespaces might have different requirements to reuse
TIME-WAIT sockets for new connections. This might be required in
cases where different namespace applications are in place which
require TIME_WAIT socket connections to be reduced independently
of the host.
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Christopher Covington reported a crash on aarch64 on recent Fedora
kernels:
kernel BUG at ./include/linux/scatterlist.h:140!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 2 PID: 752 Comm: cryptomgr_test Not tainted 4.9.0-11815-ge93b1cc #162
Hardware name: linux,dummy-virt (DT)
task: ffff80007c650080 task.stack: ffff800008910000
PC is at sg_init_one+0xa0/0xb8
LR is at sg_init_one+0x24/0xb8
...
[<ffff000008398db8>] sg_init_one+0xa0/0xb8
[<ffff000008350a44>] test_acomp+0x10c/0x438
[<ffff000008350e20>] alg_test_comp+0xb0/0x118
[<ffff00000834f28c>] alg_test+0x17c/0x2f0
[<ffff00000834c6a4>] cryptomgr_test+0x44/0x50
[<ffff0000080dac70>] kthread+0xf8/0x128
[<ffff000008082ec0>] ret_from_fork+0x10/0x50
The test vectors used for input are part of the kernel image. These
inputs are passed as a buffer to sg_init_one which eventually blows up
with BUG_ON(!virt_addr_valid(buf)). On arm64, virt_addr_valid returns
false for the kernel image since virt_to_page will not return the
correct page. Fix this by copying the input vectors to heap buffer
before setting up the scatterlist.
Reported-by: Christopher Covington <cov@codeaurora.org>
Fixes: d7db7a882d ("crypto: acomp - update testmgr with support for acomp")
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now that dax_iomap_fault() calls ->iomap_begin() without entry lock, we
can use transaction starting in ext4_iomap_begin() and thus simplify
ext4_dax_fault(). It also provides us proper retries in case of ENOSPC.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Currently ->iomap_begin() handler is called with entry lock held. If the
filesystem held any locks between ->iomap_begin() and ->iomap_end()
(such as ext4 which will want to hold transaction open), this would cause
lock inversion with the iomap_apply() from standard IO path which first
calls ->iomap_begin() and only then calls ->actor() callback which grabs
entry locks for DAX (if it faults when copying from/to user provided
buffers).
Fix the problem by nesting grabbing of entry lock inside ->iomap_begin()
- ->iomap_end() pair.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The only case when we do not finish the page fault completely is when we
are loading hole pages into a radix tree. Avoid this special case and
finish the fault in that case as well inside the DAX fault handler. It
will allow us for easier iomap handling.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Currently dax_iomap_rw() takes care of invalidating page tables and
evicting hole pages from the radix tree when write(2) to the file
happens. This invalidation is only necessary when there is some block
allocation resulting from write(2). Furthermore in current place the
invalidation is racy wrt page fault instantiating a hole page just after
we have invalidated it.
So perform the page invalidation inside dax_iomap_actor() where we can
do it only when really necessary and after blocks have been allocated so
nobody will be instantiating new hole pages anymore.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Currently invalidate_inode_pages2_range() and invalidate_mapping_pages()
just delete all exceptional radix tree entries they find. For DAX this
is not desirable as we track cache dirtiness in these entries and when
they are evicted, we may not flush caches although it is necessary. This
can for example manifest when we write to the same block both via mmap
and via write(2) (to different offsets) and fsync(2) then does not
properly flush CPU caches when modification via write(2) was the last
one.
Create appropriate DAX functions to handle invalidation of DAX entries
for invalidate_inode_pages2_range() and invalidate_mapping_pages() and
wire them up into the corresponding mm functions.
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
So far we did not return BH_New buffers from ext2_get_blocks() when we
allocated and zeroed-out a block for DAX inode to avoid racy zeroing in
DAX code. This zeroing is gone these days so we can remove the
workaround.
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
If mce_device_init() fails then the mce device pointer is NULL and the
AMD mce code happily dereferences it.
Add a sanity check.
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The attempt to prevent overwriting an active state resulted in a
disaster which effectively disables all dynamically allocated hotplug
states.
Cleanup the mess.
Fixes: dc280d9362 ("cpu/hotplug: Prevent overwriting of callbacks")
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Reported-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit beb0babfb7 ("korina: disable napi on close and restart")
introduced calls to napi_disable() that were missing before,
unfortunately this leaves a small window during which NAPI has a chance
to run, yet we just freed resources since korina_free_ring() has been
called:
Fix this by disabling NAPI first then freeing resource, and make sure
that we also cancel the restart task before doing the resource freeing.
Fixes: beb0babfb7 ("korina: disable napi on close and restart")
Reported-by: Alexandros C. Couloumbis <alex@ozo.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Shahar reported a soft lockup in tc_classify(), where we run into an
endless loop when walking the classifier chain due to tp->next == tp
which is a state we should never run into. The issue only seems to
trigger under load in the tc control path.
What happens is that in tc_ctl_tfilter(), thread A allocates a new
tp, initializes it, sets tp_created to 1, and calls into tp->ops->change()
with it. In that classifier callback we had to unlock/lock the rtnl
mutex and returned with -EAGAIN. One reason why we need to drop there
is, for example, that we need to request an action module to be loaded.
This happens via tcf_exts_validate() -> tcf_action_init/_1() meaning
after we loaded and found the requested action, we need to redo the
whole request so we don't race against others. While we had to unlock
rtnl in that time, thread B's request was processed next on that CPU.
Thread B added a new tp instance successfully to the classifier chain.
When thread A returned grabbing the rtnl mutex again, propagating -EAGAIN
and destroying its tp instance which never got linked, we goto replay
and redo A's request.
This time when walking the classifier chain in tc_ctl_tfilter() for
checking for existing tp instances we had a priority match and found
the tp instance that was created and linked by thread B. Now calling
again into tp->ops->change() with that tp was successful and returned
without error.
tp_created was never cleared in the second round, thus kernel thinks
that we need to link it into the classifier chain (once again). tp and
*back point to the same object due to the match we had earlier on. Thus
for thread B's already public tp, we reset tp->next to tp itself and
link it into the chain, which eventually causes the mentioned endless
loop in tc_classify() once a packet hits the data path.
Fix is to clear tp_created at the beginning of each request, also when
we replay it. On the paths that can cause -EAGAIN we already destroy
the original tp instance we had and on replay we really need to start
from scratch. It seems that this issue was first introduced in commit
12186be7d2 ("net_cls: fix unconfigured struct tcf_proto keeps chaining
and avoid kernel panic when we use cls_cgroup").
Fixes: 12186be7d2 ("net_cls: fix unconfigured struct tcf_proto keeps chaining and avoid kernel panic when we use cls_cgroup")
Reported-by: Shahar Klein <shahark@mellanox.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Tested-by: Shahar Klein <shahark@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I am getting the following warning when I build kernel 4.9-git on my
PowerBook G4 with a 32-bit PPC processor:
AS arch/powerpc/kernel/misc_32.o
arch/powerpc/kernel/misc_32.S:299:7: warning: "CONFIG_FSL_BOOKE" is not defined [-Wundef]
This problem is evident after commit 989cea5c14 ("kbuild: prevent
lib-ksyms.o rebuilds"); however, this change in kbuild only exposes an
error that has been in the code since 2005 when this source file was
created. That was with commit 9994a33865 ("powerpc: Introduce
entry_{32,64}.S, misc_{32,64}.S, systbl.S").
The offending line does not make a lot of sense. This error does not
seem to cause any errors in the executable, thus I am not recommending
that it be applied to any stable versions.
Thanks to Nicholas Piggin for suggesting this solution.
Fixes: 9994a33865 ("powerpc: Introduce entry_{32,64}.S, misc_{32,64}.S, systbl.S")
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The timer type simplifications caused a new gcc warning:
drivers/base/power/domain.c: In function ‘genpd_runtime_suspend’:
drivers/base/power/domain.c:562:14: warning: ‘time_start’ may be used uninitialized in this function [-Wmaybe-uninitialized]
elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
despite the actual use of "time_start" not having changed in any way.
It appears that simply changing the type of ktime_t from a union to a
plain scalar type made gcc check the use.
The variable wasn't actually used uninitialized, but gcc apparently
failed to notice that the conditional around the use was exactly the
same as the conditional around the initialization of that variable.
Add an unnecessary initialization just to shut up the compiler.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull timer type cleanups from Thomas Gleixner:
"This series does a tree wide cleanup of types related to
timers/timekeeping.
- Get rid of cycles_t and use a plain u64. The type is not really
helpful and caused more confusion than clarity
- Get rid of the ktime union. The union has become useless as we use
the scalar nanoseconds storage unconditionally now. The 32bit
timespec alike storage got removed due to the Y2038 limitations
some time ago.
That leaves the odd union access around for no reason. Clean it up.
Both changes have been done with coccinelle and a small amount of
manual mopping up"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
ktime: Get rid of ktime_equal()
ktime: Cleanup ktime_set() usage
ktime: Get rid of the union
clocksource: Use a plain u64 instead of cycle_t
Pull SMP hotplug notifier removal from Thomas Gleixner:
"This is the final cleanup of the hotplug notifier infrastructure. The
series has been reintgrated in the last two days because there came a
new driver using the old infrastructure via the SCSI tree.
Summary:
- convert the last leftover drivers utilizing notifiers
- fixup for a completely broken hotplug user
- prevent setup of already used states
- removal of the notifiers
- treewide cleanup of hotplug state names
- consolidation of state space
There is a sphinx based documentation pending, but that needs review
from the documentation folks"
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/armada-xp: Consolidate hotplug state space
irqchip/gic: Consolidate hotplug state space
coresight/etm3/4x: Consolidate hotplug state space
cpu/hotplug: Cleanup state names
cpu/hotplug: Remove obsolete cpu hotplug register/unregister functions
staging/lustre/libcfs: Convert to hotplug state machine
scsi/bnx2i: Convert to hotplug state machine
scsi/bnx2fc: Convert to hotplug state machine
cpu/hotplug: Prevent overwriting of callbacks
x86/msr: Remove bogus cleanup from the error path
bus: arm-ccn: Prevent hotplug callback leak
perf/x86/intel/cstate: Prevent hotplug callback leak
ARM/imx/mmcd: Fix broken cpu hotplug handling
scsi: qedi: Convert to hotplug state machine
Pull turbostat updates from Len Brown.
* 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
tools/power turbostat: remove obsolete -M, -m, -C, -c options
tools/power turbostat: Make extensible via the --add parameter
tools/power turbostat: Denverton uses a 25 MHz crystal, not 19.2 MHz
tools/power turbostat: line up headers when -M is used
tools/power turbostat: fix SKX PKG_CSTATE_LIMIT decoding
tools/power turbostat: Support Knights Mill (KNM)
tools/power turbostat: Display HWP OOB status
tools/power turbostat: fix Denverton BCLK
tools/power turbostat: use intel-family.h model strings
tools/power/turbostat: Add Denverton RAPL support
tools/power/turbostat: Add Denverton support
tools/power/turbostat: split core MSR support into status + limit
tools/power turbostat: fix error case overflow read of slm_freq_table[]
tools/power turbostat: Allocate correct amount of fd and irq entries
tools/power turbostat: switch to tab delimited output
tools/power turbostat: Gracefully handle ACPI S3
tools/power turbostat: tidy up output on Joule counter overflow
Add a new page flag, PageWaiters, to indicate the page waitqueue has
tasks waiting. This can be tested rather than testing waitqueue_active
which requires another cacheline load.
This bit is always set when the page has tasks on page_waitqueue(page),
and is set and cleared under the waitqueue lock. It may be set when
there are no tasks on the waitqueue, which will cause a harmless extra
wakeup check that will clears the bit.
The generic bit-waitqueue infrastructure is no longer used for pages.
Instead, waitqueues are used directly with a custom key type. The
generic code was not flexible enough to have PageWaiters manipulation
under the waitqueue lock (which simplifies concurrency).
This improves the performance of page lock intensive microbenchmarks by
2-3%.
Putting two bits in the same word opens the opportunity to remove the
memory barrier between clearing the lock bit and testing the waiters
bit, after some work on the arch primitives (e.g., ensuring memory
operand widths match and cover both bits).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A page is not added to the swap cache without being swap backed,
so PageSwapBacked mappings can use PG_owner_priv_1 for PageSwapCache.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No point in going through loops and hoops instead of just comparing the
values.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
