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Pull locking updates from Ingo Molnar:
"So we have a laundry list of locking subsystem changes:
- continuing barrier API and code improvements
- futex enhancements
- atomics API improvements
- pvqspinlock enhancements: in particular lock stealing and adaptive
spinning
- qspinlock micro-enhancements"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op
futex: Cleanup the goto confusion in requeue_pi()
futex: Remove pointless put_pi_state calls in requeue()
futex: Document pi_state refcounting in requeue code
futex: Rename free_pi_state() to put_pi_state()
futex: Drop refcount if requeue_pi() acquired the rtmutex
locking/barriers, arch: Remove ambiguous statement in the smp_store_mb() documentation
lcoking/barriers, arch: Use smp barriers in smp_store_release()
locking/cmpxchg, arch: Remove tas() definitions
locking/pvqspinlock: Queue node adaptive spinning
locking/pvqspinlock: Allow limited lock stealing
locking/pvqspinlock: Collect slowpath lock statistics
sched/core, locking: Document Program-Order guarantees
locking, sched: Introduce smp_cond_acquire() and use it
locking/pvqspinlock, x86: Optimize the PV unlock code path
locking/qspinlock: Avoid redundant read of next pointer
locking/qspinlock: Prefetch the next node cacheline
locking/qspinlock: Use _acquire/_release() versions of cmpxchg() & xchg()
atomics: Add test for atomic operations with _relaxed variants
This effectively promotes IORESOURCE_BUSY to IORESOURCE_EXCLUSIVE
semantics by default. If userspace really believes it is safe to access
the memory region it can also perform the extra step of disabling an
active driver. This protects device address ranges with read side
effects and otherwise directs userspace to use the driver.
Persistent memory presents a large "mistake surface" to /dev/mem as now
accidental writes can corrupt a filesystem.
In general if a device driver is busily using a memory region it already
informs other parts of the kernel to not touch it via
request_mem_region(). /dev/mem should honor the same safety restriction
by default. Debugging a device driver from userspace becomes more
difficult with this enabled. Any application using /dev/mem or mmap of
sysfs pci resources will now need to perform the extra step of either:
1/ Disabling the driver, for example:
echo <device id> > /dev/bus/<parent bus>/drivers/<driver name>/unbind
2/ Rebooting with "iomem=relaxed" on the command line
3/ Recompiling with CONFIG_IO_STRICT_DEVMEM=n
Traditional users of /dev/mem like dosemu are unaffected because the
first 1MB of memory is not subject to the IO_STRICT_DEVMEM restriction.
Legacy X configurations use /dev/mem to talk to graphics hardware, but
that functionality has since moved to kernel graphics drivers.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Let all the archs that implement devmem_is_allowed() opt-in to a common
definition of CONFIG_STRICT_DEVM in lib/Kconfig.debug.
Cc: Kees Cook <keescook@chromium.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
[heiko: drop 'default y' for s390]
Acked-by: Ingo Molnar <mingo@redhat.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
We might want to test for bugs like that found in commit f9692b2699bd
("firmware: fix possible use after free on name on asynchronous
request"), where the asynchronous request API had race conditions.
Let's add a simple file that will launch the async request, then wait
until it's complete and report the status. It's not a true async test
(we're using a mutex + wait_for_completion(), so we can't get more than
one going at the same time), but it does help make sure the basic API is
sane, and it can catch some class of bugs.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
We're essentially just doing an open-coded kstrndup(). The only
differences are with what happens after the first '\0' character, but
request_firmware() doesn't care about that.
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
request_firmware() failures currently won't get reported at all (the
error code is discarded). What's more, we get confusing messages, like:
# echo -n notafile > /sys/devices/virtual/misc/test_firmware/trigger_request
[ 8280.311856] test_firmware: loading 'notafile'
[ 8280.317042] test_firmware: load of 'notafile' failed: -2
[ 8280.322445] test_firmware: loaded: 0
# echo $?
0
Report the failures via write() errors, and don't say we "loaded"
anything.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
This allow to directly print block_device name.
Currently one should use bdevname() with temporal char buffer.
This is very ineffective because bloat stack usage for deep IO call-traces
Example:
%pg -> sda, sda1 or loop0p1
[AV: fixed a minor braino - position updates should not be dependent
upon having reached the of buffer]
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull RCU changes from Paul E. McKenney:
- Adding transitivity uniformly to rcu_node structure ->lock
acquisitions. (This is implemented by the first two commits
on top of v4.4-rc2 due to the pervasive nature of this change.)
- Documentation updates, including RCU requirements.
- Expedited grace-period changes.
- Miscellaneous fixes.
- Linked-list fixes, courtesy of KTSAN.
- Torture-test updates.
- Late-breaking fix to sysrq-generated crash.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A _lot_ of ->write() instances were open-coding it; some are
converted to memdup_user_nul(), a lot more remain...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
commit 5ac48378414d ("tracing: Use trace_seq_used() and seq_buf_used()
instead of len") changed the tracing code to use trace_seq_used() and
seq_buf_used() instead of using the seq_buf len directly to avoid
overflow issues, but missed a spot in seq_buf_to_user() that makes use
of s->len.
Cleaned up the code a bit as well per suggestion of Steve Rostedt.
Link: http://lkml.kernel.org/r/1447703848-2951-1-git-send-email-jsnitsel@redhat.com
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Remove the WARN() from the beN_to_cpu macro, which is used as a param to a
pr_debug() call. With a certain kernel config, this printk-in-printk
results in the no_printk() macro trying to recursively call the
no_printk() macro, and since macros can't recursively call themselves
a build error results.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Use genalloc to manage CPM/QE muram instead of rheap.
Signed-off-by: Zhao Qiang <qiang.zhao@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Add new algo for genalloc, it reserve a specific region of
memory
Signed-off-by: Zhao Qiang <qiang.zhao@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Bytes alignment is required to manage some special RAM,
so add gen_pool_first_fit_align to genalloc,
meanwhile add gen_pool_alloc_algo to pass algo in case user
layer using more than one algo, and pass data to
gen_pool_first_fit_align(modify gen_pool_alloc as a wrapper)
Signed-off-by: Zhao Qiang <qiang.zhao@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Fault-injection capability for MMC IO uses debugfs entries to configure
the attributes.
FAULT_INJECTION_DEBUG_FS must be enabled to use FAIL_MMC_REQUEST.
Replace FAULT_INJECTION with FAULT_INJECTION_DEBUG_FS.
Also remove 'select DEBUG_FS' since FAULT_INJECTION_DEBUG_FS depends on
it.
Signed-off-by: Adrien Schildknecht <adrien+dev@schischi.me>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The commit c6ff5268293ef98e48a99597e765ffc417e39fa5 ("rhashtable:
Fix walker list corruption") causes a suspicious RCU usage warning
because we no longer hold ht->mutex when we dereference ht->tbl.
However, this is a false positive because we now hold ht->lock
which also guarantees that ht->tbl won't disppear from under us.
This patch kills the warning by using rcu_dereference_protected.
Reported-by: kernel test robot <ying.huang@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add couple of test cases for interpreter but also JITs, f.e. to test that
when imm32 moves are being done, upper 32bits of the regs are being zero
extended.
Without JIT:
[...]
[ 1114.129301] test_bpf: #43 MOV REG64 jited:0 128 PASS
[ 1114.130626] test_bpf: #44 MOV REG32 jited:0 139 PASS
[ 1114.132055] test_bpf: #45 LD IMM64 jited:0 124 PASS
[...]
With JIT (generated code can as usual be nicely verified with the help of
bpf_jit_disasm tool):
[...]
[ 1062.726782] test_bpf: #43 MOV REG64 jited:1 6 PASS
[ 1062.726890] test_bpf: #44 MOV REG32 jited:1 6 PASS
[ 1062.726993] test_bpf: #45 LD IMM64 jited:1 6 PASS
[...]
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/geneve.c
Here we had an overlapping change, where in 'net' the extraneous stats
bump was being removed whilst in 'net-next' the final argument to
udp_tunnel6_xmit_skb() was being changed.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
1) Fix uninitialized variable warnings in nfnetlink_queue, a lot of
people reported this... From Arnd Bergmann.
2) Don't init mutex twice in i40e driver, from Jesse Brandeburg.
3) Fix spurious EBUSY in rhashtable, from Herbert Xu.
4) Missing DMA unmaps in mvpp2 driver, from Marcin Wojtas.
5) Fix race with work structure access in pppoe driver causing
corruptions, from Guillaume Nault.
6) Fix OOPS due to sh_eth_rx() not checking whether netdev_alloc_skb()
actually succeeded or not, from Sergei Shtylyov.
7) Don't lose flags when settifn IFA_F_OPTIMISTIC in ipv6 code, from
Bjørn Mork.
8) VXLAN_HD_RCO defined incorrectly, fix from Jiri Benc.
9) Fix clock source used for cookies in SCTP, from Marcelo Ricardo
Leitner.
10) aurora driver needs HAS_DMA dependency, from Geert Uytterhoeven.
11) ndo_fill_metadata_dst op of vxlan has to handle ipv6 tunneling
properly as well, from Jiri Benc.
12) Handle request sockets properly in xfrm layer, from Eric Dumazet.
13) Double stats update in ipv6 geneve transmit path, fix from Pravin B
Shelar.
14) sk->sk_policy[] needs RCU protection, and as a result
xfrm_policy_destroy() needs to free policies using an RCU grace
period, from Eric Dumazet.
15) SCTP needs to clone ipv6 tx options in order to avoid use after
free, from Eric Dumazet.
16) Missing kbuild export if ila.h, from Stephen Hemminger.
17) Missing mdiobus_alloc() return value checking in mdio-mux.c, from
Tobias Klauser.
18) Validate protocol value range in ->create() methods, from Hannes
Frederic Sowa.
19) Fix early socket demux races that result in illegal dst reuse, from
Eric Dumazet.
20) Validate socket address length in pptp code, from WANG Cong.
21) skb_reorder_vlan_header() uses incorrect offset and can corrupt
packets, from Vlad Yasevich.
22) Fix memory leaks in nl80211 registry code, from Ola Olsson.
23) Timeout loop count handing fixes in mISDN, xgbe, qlge, sfc, and
qlcnic. From Dan Carpenter.
24) msg.msg_iocb needs to be cleared in recvfrom() otherwise, for
example, AF_ALG will interpret it as an async call. From Tadeusz
Struk.
25) inetpeer_set_addr_v4 forgets to initialize the 'vif' field, from
Eric Dumazet.
26) rhashtable enforces the minimum table size not early enough,
breaking how we calculate the per-cpu lock allocations. From
Herbert Xu.
27) Fix FCC port lockup in 82xx driver, from Martin Roth.
28) FOU sockets need to be freed using RCU, from Hannes Frederic Sowa.
29) Fix out-of-bounds access in __skb_complete_tx_timestamp() and
sock_setsockopt() wrt. timestamp handling. From WANG Cong.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (117 commits)
net: check both type and procotol for tcp sockets
drivers: net: xgene: fix Tx flow control
tcp: restore fastopen with no data in SYN packet
af_unix: Revert 'lock_interruptible' in stream receive code
fou: clean up socket with kfree_rcu
82xx: FCC: Fixing a bug causing to FCC port lock-up
gianfar: Don't enable RX Filer if not supported
net: fix warnings in 'make htmldocs' by moving macro definition out of field declaration
rhashtable: Fix walker list corruption
rhashtable: Enforce minimum size on initial hash table
inet: tcp: fix inetpeer_set_addr_v4()
ipv6: automatically enable stable privacy mode if stable_secret set
net: fix uninitialized variable issue
bluetooth: Validate socket address length in sco_sock_bind().
net_sched: make qdisc_tree_decrease_qlen() work for non mq
ser_gigaset: remove unnecessary kfree() calls from release method
ser_gigaset: fix deallocation of platform device structure
ser_gigaset: turn nonsense checks into WARN_ON
ser_gigaset: fix up NULL checks
qlcnic: fix a timeout loop
...
Pull libnvdimm fixes from Dan Williams:
- Two bug fixes for misuse of PAGE_MASK in scatterlist and dma-debug.
These are tagged for -stable. The scatterlist impact is potentially
corrupted dma addresses on HIGHMEM enabled platforms.
- A minor locking fix for the NFIT hot-add implementation that is new
in 4.4-rc. This would only trigger in the case a hot-add raced
driver removal.
* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
dma-debug: Fix dma_debug_entry offset calculation
Revert "scatterlist: use sg_phys()"
nfit: acpi_nfit_notify(): Do not leave device locked
This converts the generic user string functions to use the batched user
access functions.
It makes a big difference on Skylake, which is the first x86
microarchitecture to implement SMAP. The STAC/CLAC instructions are not
very fast, and doing them for each access inside the loop that copies
strings from user space (which is what the pathname handling does for
every pathname the kernel uses, for example) is very inefficient.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dma-debug uses struct dma_debug_entry to keep track of dma coherent
memory allocation requests. The virtual address is converted into a pfn
and an offset. Previously, the offset was calculated using an incorrect
bit mask. As a result, we saw incorrect error messages from dma-debug
like the following:
"DMA-API: exceeded 7 overlapping mappings of cacheline 0x03e00000"
Cacheline 0x03e00000 does not exist on our platform.
Cc: <stable@vger.kernel.org>
Fixes: 0abdd7a81b7e ("dma-debug: introduce debug_dma_assert_idle()")
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The commit ba7c95ea3870fe7b847466d39a049ab6f156aa2c ("rhashtable:
Fix sleeping inside RCU critical section in walk_stop") introduced
a new spinlock for the walker list. However, it did not convert
all existing users of the list over to the new spin lock. Some
continued to use the old mutext for this purpose. This obviously
led to corruption of the list.
The fix is to use the spin lock everywhere where we touch the list.
This also allows us to do rcu_rad_lock before we take the lock in
rhashtable_walk_start. With the old mutex this would've deadlocked
but it's safe with the new spin lock.
Fixes: ba7c95ea3870 ("rhashtable: Fix sleeping inside RCU...")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
William Hua <william.hua@canonical.com> wrote:
>
> I wasn't aware there was an enforced minimum size. I simply set the
> nelem_hint in the rhastable_params struct to 1, expecting it to grow as
> needed. This caused a segfault afterwards when trying to insert an
> element.
OK we're doing the size computation before we enforce the limit
on min_size.
---8<---
We need to do the initial hash table size computation after we
have obtained the correct min_size/max_size parameters. Otherwise
we may end up with a hash table whose size is outside the allowed
envelope.
Fixes: a998f712f77e ("rhashtable: Round up/down min/max_size to...")
Reported-by: William Hua <william.hua@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is no good reason to keep them apart, and this makes using the API
a bit simpler.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
There is no good reason to start out disabled - drivers can control if
the poll instance can be scheduled by simply not scheduling it yet.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
The new name is irq_poll as iopoll is already taken. Better suggestions
welcome.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
The patch 9497df88ab5567daa001829051c5f87161a81ff0 ("rhashtable:
Fix reader/rehash race") added a pair of barriers. In fact the
wmb is superfluous because every subsequent write to the old or
new hash table uses rcu_assign_pointer, which itself carriers a
full barrier prior to the assignment.
Therefore we may remove the explicit wmb.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Workqueue stalls can happen from a variety of usage bugs such as
missing WQ_MEM_RECLAIM flag or concurrency managed work item
indefinitely staying RUNNING. These stalls can be extremely difficult
to hunt down because the usual warning mechanisms can't detect
workqueue stalls and the internal state is pretty opaque.
To alleviate the situation, this patch implements workqueue lockup
detector. It periodically monitors all worker_pools periodically and,
if any pool failed to make forward progress longer than the threshold
duration, triggers warning and dumps workqueue state as follows.
BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 31s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=17/256
pending: monkey_wrench_fn, e1000_watchdog, cache_reap, vmstat_shepherd, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, release_one_tty, cgroup_release_agent
workqueue events_power_efficient: flags=0x80
pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256
pending: check_lifetime, neigh_periodic_work
workqueue cgroup_pidlist_destroy: flags=0x0
pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1
pending: cgroup_pidlist_destroy_work_fn
...
The detection mechanism is controller through kernel parameter
workqueue.watchdog_thresh and can be updated at runtime through the
sysfs module parameter file.
v2: Decoupled from softlockup control knobs.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
asm/atomic.h doesn't really need asm/processor.h anymore. Everything
it uses has moved to other header files. So remove that include.
processor.h is a nasty header that includes lots of
other headers and makes it prone to include loops. Removing the
include here makes asm/atomic.h a "leaf" header that can
be safely included in most other headers.
The only fallout is in the lib/atomic tester which relied on
this implicit include. Give it an explicit include.
(the include is in ifdef because the user is also in ifdef)
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/1449018060-1742-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This reverts commit d3716f18a7d841565c930efde30737a3557eee69.
vmalloc cannot be used in BH disabled contexts, even
with GFP_ATOMIC. And we certainly want to support
rhashtable users inserting entries with software
interrupts disabled.
Signed-off-by: David S. Miller <davem@davemloft.net>
When an rhashtable user pounds rhashtable hard with back-to-back
insertions we may end up growing the table in GFP_ATOMIC context.
Unfortunately when the table reaches a certain size this often
fails because we don't have enough physically contiguous pages
to hold the new table.
Eric Dumazet suggested (and in fact wrote this patch) using
__vmalloc instead which can be used in GFP_ATOMIC context.
Reported-by: Phil Sutter <phil@nwl.cc>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Thomas and Phil observed that under stress rhashtable insertion
sometimes failed with EBUSY, even though this error should only
ever been seen when we're under attack and our hash chain length
has grown to an unacceptable level, even after a rehash.
It turns out that the logic for detecting whether there is an
existing rehash is faulty. In particular, when two threads both
try to grow the same table at the same time, one of them may see
the newly grown table and thus erroneously conclude that it had
been rehashed. This is what leads to the EBUSY error.
This patch fixes this by remembering the current last table we
used during insertion so that rhashtable_insert_rehash can detect
when another thread has also done a resize/rehash. When this is
detected we will give up our resize/rehash and simply retry the
insertion with the new table.
Reported-by: Thomas Graf <tgraf@suug.ch>
Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since CHANGEUPPER can now fail, add support for it in the newly
introduced netdev notifier error injection infrastructure.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This module allows to insert errors in some of netdevice's notifier
events. All network drivers use these notifiers to signal various events
and to check if they are allowed, e.g. PRECHANGEMTU and CHANGEMTU
afterwards. Until recently I had to run failure tests by injecting
a custom module, but now this infrastructure makes it trivial to test
these failure paths. Some of the recent bugs I fixed were found using
this module.
Here's an example:
$ cd /sys/kernel/debug/notifier-error-inject/netdev
$ echo -22 > actions/NETDEV_CHANGEMTU/error
$ ip link set eth0 mtu 1024
RTNETLINK answers: Invalid argument
CC: Akinobu Mita <akinobu.mita@gmail.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: netdev <netdev@vger.kernel.org>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The enable_kernel_*() functions leave the relevant MSR bits enabled
until we exit the kernel sometime later. Create disable versions
that wrap the kernel use of FP, Altivec VSX or SPE.
While we don't want to disable it normally for performance reasons
(MSR writes are slow), it will be used for a debug boot option that
does this and catches bad uses in other areas of the kernel.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fix the semantic of lc_seq_printf. Currently, it always returns 0 and
the return value is unused, therefore, convert the return type to void.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Code that does lockless emptiness testing of non-RCU lists is relying
on the list-addition code to write the list head's ->next pointer
atomically. This commit therefore adds WRITE_ONCE() to list-addition
pointer stores that could affect the head's ->next pointer.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This is rather a hack to expose the current issue with rhashtable to
under high pressure sometimes return -ENOMEM even though system memory
is not exhausted and a consecutive insert may succeed.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
A maximum table size of 64k entries is insufficient for the multiple
threads test even in default configuration (10 threads * 50000 objects =
500000 objects in total). Since we know how many objects will be
inserted, calculate the max size unless overridden by parameter.
Note that specifying the exact number of objects upon table init won't
suffice as that value is being rounded down to the next power of two -
anticipate this by rounding up to the next power of two in beforehand.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
After adding cond_resched() calls to threadfunc(), a surprisingly high
rate of insert failures occurred probably due to table resizes getting a
better chance to run in background. To not soften up the remaining
tests, retry inserts until they either succeed or fail permanently.
Also change the non-threaded test to retry insert operations, too.
Suggested-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
