- 09 Oct, 2014 9 commits
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Andrew Hunter authored
commit d78c9300 upstream. timeval_to_jiffies tried to round a timeval up to an integral number of jiffies, but the logic for doing so was incorrect: intervals corresponding to exactly N jiffies would become N+1. This manifested itself particularly repeatedly stopping/starting an itimer: setitimer(ITIMER_PROF, &val, NULL); setitimer(ITIMER_PROF, NULL, &val); would add a full tick to val, _even if it was exactly representable in terms of jiffies_ (say, the result of a previous rounding.) Doing this repeatedly would cause unbounded growth in val. So fix the math. Here's what was wrong with the conversion: we essentially computed (eliding seconds) jiffies = usec * (NSEC_PER_USEC/TICK_NSEC) by using scaling arithmetic, which took the best approximation of NSEC_PER_USEC/TICK_NSEC with denominator of 2^USEC_JIFFIE_SC = x/(2^USEC_JIFFIE_SC), and computed: jiffies = (usec * x) >> USEC_JIFFIE_SC and rounded this calculation up in the intermediate form (since we can't necessarily exactly represent TICK_NSEC in usec.) But the scaling arithmetic is a (very slight) *over*approximation of the true value; that is, instead of dividing by (1 usec/ 1 jiffie), we effectively divided by (1 usec/1 jiffie)-epsilon (rounding down). This would normally be fine, but we want to round timeouts up, and we did so by adding 2^USEC_JIFFIE_SC - 1 before the shift; this would be fine if our division was exact, but dividing this by the slightly smaller factor was equivalent to adding just _over_ 1 to the final result (instead of just _under_ 1, as desired.) In particular, with HZ=1000, we consistently computed that 10000 usec was 11 jiffies; the same was true for any exact multiple of TICK_NSEC. We could possibly still round in the intermediate form, adding something less than 2^USEC_JIFFIE_SC - 1, but easier still is to convert usec->nsec, round in nanoseconds, and then convert using time*spec*_to_jiffies. This adds one constant multiplication, and is not observably slower in microbenchmarks on recent x86 hardware. Tested: the following program: int main() { struct itimerval zero = {{0, 0}, {0, 0}}; /* Initially set to 10 ms. */ struct itimerval initial = zero; initial.it_interval.tv_usec = 10000; setitimer(ITIMER_PROF, &initial, NULL); /* Save and restore several times. */ for (size_t i = 0; i < 10; ++i) { struct itimerval prev; setitimer(ITIMER_PROF, &zero, &prev); /* on old kernels, this goes up by TICK_USEC every iteration */ printf("previous value: %ld %ld %ld %ld\n", prev.it_interval.tv_sec, prev.it_interval.tv_usec, prev.it_value.tv_sec, prev.it_value.tv_usec); setitimer(ITIMER_PROF, &prev, NULL); } return 0; } Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul Turner <pjt@google.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Reviewed-by:
Paul Turner <pjt@google.com> Reported-by:
Aaron Jacobs <jacobsa@google.com> Signed-off-by:
Andrew Hunter <ahh@google.com> [jstultz: Tweaked to apply to 3.17-rc] Signed-off-by:
John Stultz <john.stultz@linaro.org> [bwh: Backported to 3.16: adjust filename] Signed-off-by:
Ben Hutchings <ben@decadent.org.uk> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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NeilBrown authored
commit 8e0e99ba upstream. It has come to my attention (thanks Martin) that 'discard_zeroes_data' is only a hint. Some devices in some cases don't do what it says on the label. The use of DISCARD in RAID5 depends on reads from discarded regions being predictably zero. If a write to a previously discarded region performs a read-modify-write cycle it assumes that the parity block was consistent with the data blocks. If all were zero, this would be the case. If some are and some aren't this would not be the case. This could lead to data corruption after a device failure when data needs to be reconstructed from the parity. As we cannot trust 'discard_zeroes_data', ignore it by default and so disallow DISCARD on all raid4/5/6 arrays. As many devices are trustworthy, and as there are benefits to using DISCARD, add a module parameter to over-ride this caution and cause DISCARD to work if discard_zeroes_data is set. If a site want to enable DISCARD on some arrays but not on others they should select DISCARD support at the filesystem level, and set the raid456 module parameter. raid456.devices_handle_discard_safely=Y As this is a data-safety issue, I believe this patch is suitable for -stable. DISCARD support for RAID456 was added in 3.7 Cc: Shaohua Li <shli@kernel.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Heinz Mauelshagen <heinzm@redhat.com> Acked-by:
Martin K. Petersen <martin.petersen@oracle.com> Acked-by:
Mike Snitzer <snitzer@redhat.com> Fixes: 620125f2Signed-off-by:
NeilBrown <neilb@suse.de> [bwh: Backported to 3.10: adjust context] Signed-off-by:
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Hans Verkuil authored
commit 58d75f4b upstream. The recent conversion of saa7134 to vb2 unconvered a poll() bug that broke the teletext applications alevt and mtt. These applications expect that calling poll() without having called VIDIOC_STREAMON will cause poll() to return POLLERR. That did not happen in vb2. This patch fixes that behavior. It also fixes what should happen when poll() is called when STREAMON is called but no buffers have been queued. In that case poll() will also return POLLERR, but only for capture queues since output queues will always return POLLOUT anyway in that situation. This brings the vb2 behavior in line with the old videobuf behavior. Signed-off-by:
Hans Verkuil <hans.verkuil@cisco.com> Acked-by:
Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by:
Mauro Carvalho Chehab <mchehab@osg.samsung.com> Signed-off-by:
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Mel Gorman authored
commit abc40bd2 upstream. This patch reverts 1ba6e0b5 ("mm: numa: split_huge_page: transfer the NUMA type from the pmd to the pte"). If a huge page is being split due a protection change and the tail will be in a PROT_NONE vma then NUMA hinting PTEs are temporarily created in the protected VMA. VM_RW|VM_PROTNONE |-----------------| ^ split here In the specific case above, it should get fixed up by change_pte_range() but there is a window of opportunity for weirdness to happen. Similarly, if a huge page is shrunk and split during a protection update but before pmd_numa is cleared then a pte_numa can be left behind. Instead of adding complexity trying to deal with the case, this patch will not mark PTEs NUMA when splitting a huge page. NUMA hinting faults will not be triggered which is marginal in comparison to the complexity in dealing with the corner cases during THP split. Signed-off-by:
Mel Gorman <mgorman@suse.de> Acked-by:
Rik van Riel <riel@redhat.com> Acked-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Waiman Long authored
commit f8303c25 upstream. In __split_huge_page_map(), the check for page_mapcount(page) is invariant within the for loop. Because of the fact that the macro is implemented using atomic_read(), the redundant check cannot be optimized away by the compiler leading to unnecessary read to the page structure. This patch moves the invariant bug check out of the loop so that it will be done only once. On a 3.16-rc1 based kernel, the execution time of a microbenchmark that broke up 1000 transparent huge pages using munmap() had an execution time of 38,245us and 38,548us with and without the patch respectively. The performance gain is about 1%. Signed-off-by:
Waiman Long <Waiman.Long@hp.com> Acked-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
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Steven Rostedt (Red Hat) authored
commit 24607f11 upstream. Commit 651e22f2 "ring-buffer: Always reset iterator to reader page" fixed one bug but in the process caused another one. The reset is to update the header page, but that fix also changed the way the cached reads were updated. The cache reads are used to test if an iterator needs to be updated or not. A ring buffer iterator, when created, disables writes to the ring buffer but does not stop other readers or consuming reads from happening. Although all readers are synchronized via a lock, they are only synchronized when in the ring buffer functions. Those functions may be called by any number of readers. The iterator continues down when its not interrupted by a consuming reader. If a consuming read occurs, the iterator starts from the beginning of the buffer. The way the iterator sees that a consuming read has happened since its last read is by checking the reader "cache". The cache holds the last counts of the read and the reader page itself. Commit 651e22f2 changed what was saved by the cache_read when the rb_iter_reset() occurred, making the iterator never match the cache. Then if the iterator calls rb_iter_reset(), it will go into an infinite loop by checking if the cache doesn't match, doing the reset and retrying, just to see that the cache still doesn't match! Which should never happen as the reset is suppose to set the cache to the current value and there's locks that keep a consuming reader from having access to the data. Fixes: 651e22f2 "ring-buffer: Always reset iterator to reader page" Signed-off-by:
Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
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Josh Triplett authored
commit 62b4d204 upstream. commit 03b8c7b6 ("futex: Allow architectures to skip futex_atomic_cmpxchg_inatomic() test") added the HAVE_FUTEX_CMPXCHG symbol right below FUTEX. This placed it right in the middle of the options for the EXPERT menu. However, HAVE_FUTEX_CMPXCHG does not depend on EXPERT or FUTEX, so Kconfig stops placing items in the EXPERT menu, and displays the remaining several EXPERT items (starting with EPOLL) directly in the General Setup menu. Since both users of HAVE_FUTEX_CMPXCHG only select it "if FUTEX", make HAVE_FUTEX_CMPXCHG itself depend on FUTEX. With this change, the subsequent items display as part of the EXPERT menu again; the EMBEDDED menu now appears as the next top-level item in the General Setup menu, which makes General Setup much shorter and more usable. Signed-off-by:
Josh Triplett <josh@joshtriplett.org> Acked-by:
Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
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Peter Zijlstra authored
commit 6c72e350 upstream. Oleg noticed that a cleanup by Sylvain actually uncovered a bug; by calling perf_event_free_task() when failing sched_fork() we will not yet have done the memset() on ->perf_event_ctxp[] and will therefore try and 'free' the inherited contexts, which are still in use by the parent process. This is bad.. Suggested-by:
Oleg Nesterov <oleg@redhat.com> Reported-by:
Sylvain 'ythier' Hitier <sylvain.hitier@gmail.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Jan Kara authored
commit c03aa9f6 upstream. We did not implement any bound on number of indirect ICBs we follow when loading inode. Thus corrupted medium could cause kernel to go into an infinite loop, possibly causing a stack overflow. Fix the possible stack overflow by removing recursion from __udf_read_inode() and limit number of indirect ICBs we follow to avoid infinite loops. Signed-off-by:
Jan Kara <jack@suse.cz> Cc: Chuck Ebbert <cebbert.lkml@gmail.com> Signed-off-by:
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- 05 Oct, 2014 31 commits
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Greg Kroah-Hartman authored
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Oleg Nesterov authored
commit 4449a51a upstream. Aleksei hit the soft lockup during reading /proc/PID/smaps. David investigated the problem and suggested the right fix. while_each_thread() is racy and should die, this patch updates vm_is_stack(). Signed-off-by:
Aleksei Besogonov <alex.besogonov@gmail.com> Tested-by:
David Rientjes <rientjes@google.com> Signed-off-by:
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Oleg Nesterov authored
commit 4d4048be upstream. find_lock_task_mm() expects it is called under rcu or tasklist lock, but it seems that at least oom_unkillable_task()->task_in_mem_cgroup() and mem_cgroup_out_of_memory()->oom_badness() can call it lockless. Perhaps we could fix the callers, but this patch simply adds rcu lock into find_lock_task_mm(). This also allows to simplify a bit one of its callers, oom_kill_process(). Signed-off-by:
Michal Hocko <mhocko@suse.cz> Cc: "Tu, Xiaobing" <xiaobing.tu@intel.com> Acked-by:
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Oleg Nesterov authored
commit ad962441 upstream. At least out_of_memory() calls has_intersects_mems_allowed() without even rcu_read_lock(), this is obviously buggy. Add the necessary rcu_read_lock(). This means that we can not simply return from the loop, we need "bool ret" and "break". While at it, swap the names of task_struct's (the argument and the local). This cleans up the code a little bit and avoids the unnecessary initialization. Signed-off-by:
Sergey Dyasly <dserrg@gmail.com> Tested-by:
Sameer Nanda <snanda@chromium.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mandeep Singh Baines <msb@chromium.org> Cc: "Ma, Xindong" <xindong.ma@intel.com> Reviewed-by:
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Oleg Nesterov authored
commit 1da4db0c upstream. Change oom_kill.c to use for_each_thread() rather than the racy while_each_thread() which can loop forever if we race with exit. Note also that most users were buggy even if while_each_thread() was fine, the task can exit even _before_ rcu_read_lock(). Fortunately the new for_each_thread() only requires the stable task_struct, so this change fixes both problems. Signed-off-by:
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Oleg Nesterov authored
commit 0c740d0a upstream. while_each_thread() and next_thread() should die, almost every lockless usage is wrong. 1. Unless g == current, the lockless while_each_thread() is not safe. while_each_thread(g, t) can loop forever if g exits, next_thread() can't reach the unhashed thread in this case. Note that this can happen even if g is the group leader, it can exec. 2. Even if while_each_thread() itself was correct, people often use it wrongly. It was never safe to just take rcu_read_lock() and loop unless you verify that pid_alive(g) == T, even the first next_thread() can point to the already freed/reused memory. This patch adds signal_struct->thread_head and task->thread_node to create the normal rcu-safe list with the stable head. The new for_each_thread(g, t) helper is always safe under rcu_read_lock() as long as this task_struct can't go away. Note: of course it is ugly to have both task_struct->thread_node and the old task_struct->thread_group, we will kill it later, after we change the users of while_each_thread() to use for_each_thread(). Perhaps we can kill it even before we convert all users, we can reimplement next_thread(t) using the new thread_head/thread_node. But we can't do this right now because this will lead to subtle behavioural changes. For example, do/while_each_thread() always sees at least one task, while for_each_thread() can do nothing if the whole thread group has died. Or thread_group_empty(), currently its semantics is not clear unless thread_group_leader(p) and we need to audit the callers before we can change it. So this patch adds the new interface which has to coexist with the old one for some time, hopefully the next changes will be more or less straightforward and the old one will go away soon. Signed-off-by:
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Oleg Nesterov authored
commit 80628ca0 upstream. Cleanup and preparation for the next changes. Move the "if (clone_flags & CLONE_THREAD)" code down under "if (likely(p->pid))" and turn it into into the "else" branch. This makes the process/thread initialization more symmetrical and removes one check. Signed-off-by:
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Soren Brinkmann authored
commit 90de827b upstream. Signed-off-by:
Soren Brinkmann <soren.brinkmann@xilinx.com> Signed-off-by:
Michal Simek <michal.simek@xilinx.com> Signed-off-by:
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Jan Kara authored
commit 7ba3ec57 upstream. Commit 8e3dffc6 "Ext2: mark inode dirty after the function dquot_free_block_nodirty is called" unveiled a bug in __ext2_get_block() called from ext2_get_xip_mem(). That function called ext2_get_block() mistakenly asking it to map 0 blocks while 1 was intended. Before the above mentioned commit things worked out fine by luck but after that commit we started returning that we allocated 0 blocks while we in fact allocated 1 block and thus allocation was looping until all blocks in the filesystem were exhausted. Fix the problem by properly asking for one block and also add assertion in ext2_get_blocks() to catch similar problems. Reported-and-tested-by:
Andiry Xu <andiry.xu@gmail.com> Signed-off-by:
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Heikki Krogerus authored
commit d4089a33 upstream. Using dma_mapping_error() to make sure the mapping did not fail. Signed-off-by:
Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: "Petallo, MauriceX R" <mauricex.r.petallo@intel.com> Signed-off-by:
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Will Deacon authored
commit 1aa2b3b7 upstream. Running an OABI_COMPAT kernel on an SMP platform can lead to fun and games with page aging. If one CPU issues a swi instruction immediately before another CPU decides to mkold the page containing the swi instruction, then we will fault attempting to load the instruction during the vector_swi handler in order to retrieve its immediate field. Since this fault is not currently dealt with by our exception tables, this results in a panic: Unable to handle kernel paging request at virtual address 4020841c pgd = c490c000 [4020841c] *pgd=84451831, *pte=bf05859d, *ppte=00000000 Internal error: Oops: 17 [#1] PREEMPT SMP ARM Modules linked in: hid_sony(O) CPU: 1 Tainted: G W O (3.4.0-perf-gf496dca-01162-gcbcc62b #1) PC is at vector_swi+0x28/0x88 LR is at 0x40208420 This patch wraps all of the swi instruction loads with the USER macro and provides a shared exception table entry which simply rewinds the saved user PC and returns from the system call (without setting tbl, so there's no worries with tracing or syscall restarting). Returning to userspace will re-enter the page fault handler, from where we will probably send SIGSEGV to the current task. Reported-by:
Wang, Yalin <yalin.wang@sonymobile.com> Reviewed-by:
Nicolas Pitre <nico@linaro.org> Signed-off-by:
Will Deacon <will.deacon@arm.com> Signed-off-by:
Russell King <rmk+kernel@arm.linux.org.uk> Cc: Sheng Yong <shengyong1@huawei.com> Signed-off-by:
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Florian Westphal authored
commit 6547a221 upstream. When loose tracking is enabled (default), non-syn packets cause creation of new conntracks in established state with default timeout for established state (5 days). This causes the table to fill up with UNREPLIED when the 'new ack' packet happened to be the last-ack of a previous, already timed-out connection. Consider: A 192.168.x.52792 > 10.184.y.80: F, 426:426(0) ack 9237 win 255 B 10.184.y.80 > 192.168.x.52792: ., ack 427 win 123 <61 second pause> C 10.184.y.80 > 192.168.x.52792: F, 9237:9237(0) ack 427 win 123 D 192.168.x.52792 > 10.184.y.80: ., ack 9238 win 255 B moves conntrack to CLOSE_WAIT and will kill it after 60 second timeout, C is ignored (FIN set), but last packet (D) causes new ct with 5-days timeout. Use UNACK timeout (5 minutes) instead to get rid of these entries sooner when in ESTABLISHED state without having seen traffic in both directions. Signed-off-by:
Florian Westphal <fw@strlen.de> Acked-by:
Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by:
Pablo Neira Ayuso <pablo@netfilter.org> Cc: Florian Koch <florian.koch1981@gmail.com> Signed-off-by:
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Rafael J. Wysocki authored
commit 43e8317b upstream. Use the observation that, for platform-dependent sleep states (PM_SUSPEND_STANDBY, PM_SUSPEND_MEM), a given state is either always supported or always unsupported and store that information in pm_states[] instead of calling valid_state() every time we need to check it. Also do not use valid_state() for PM_SUSPEND_FREEZE, which is always valid, and move the pm_test_level validity check for PM_SUSPEND_FREEZE directly into enter_state(). Signed-off-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Brian Norris <computersforpeace@gmail.com> Signed-off-by:
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Rafael J. Wysocki authored
commit 27ddcc65 upstream. To allow sleep states corresponding to the "mem", "standby" and "freeze" lables to be different from the pm_states[] indexes of those strings, introduce struct pm_sleep_state, consisting of a string label and a state number, and turn pm_states[] into an array of objects of that type. This modification should not lead to any functional changes. Signed-off-by:
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Julian Anastasov authored
commit eb90b0c7 upstream. commit fc604767 ("ipvs: changes for local real server") from 2.6.37 introduced DNAT support to local real server but the IPv6 LOCAL_OUT handler ip_vs_local_reply6() is registered incorrectly as IPv4 hook causing any outgoing IPv4 traffic to be dropped depending on the IP header values. Chris tracked down the problem to CONFIG_IP_VS_IPV6=y Bug report: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1349768Reported-by:
Chris J Arges <chris.j.arges@canonical.com> Tested-by:
Julian Anastasov <ja@ssi.bg> Signed-off-by:
Simon Horman <horms@verge.net.au> Signed-off-by:
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Alex Gartrell authored
commit 76f084bc upstream. Previously, only the four high bits of the tclass were maintained in the ipv6 case. This matches the behavior of ipv4, though whether or not we should reflect ECN bits may be up for debate. Signed-off-by:
Alex Gartrell <agartrell@fb.com> Acked-by:
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Julian Anastasov authored
commit 2627b7e1 upstream. commit 8f4e0a18 ("IPVS netns exit causes crash in conntrack") added second ip_vs_conn_drop_conntrack call instead of just adding the needed check. As result, the first call still can cause crash on netns exit. Remove it. Signed-off-by:
Hans Schillstrom <hans@schillstrom.com> Signed-off-by:
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NeilBrown authored
commit b8cb6b4c upstream. If a devices is being recovered it is not InSync and is not Faulty. If a read error is experienced on that device, fix_read_error() will be called, but it ignores non-InSync devices. So it will neither fix the error nor fail the device. It is incorrect that fix_read_error() ignores non-InSync devices. It should only ignore Faulty devices. So fix it. This became a bug when we allowed reading from a device that was being recovered. It is suitable for any subsequent -stable kernel. Fixes: da8840a7Reported-by:
Alexander Lyakas <alex.bolshoy@gmail.com> Tested-by:
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Hans Verkuil authored
commit 6a03dc92 upstream. This was caused by an uninitialized setup.config field. Based on a suggestion from Devin Heitmueller. Signed-off-by:
Scott Robinson <scott.robinson55@gmail.com> Tested-by:
Mauro Carvalho Chehab <m.chehab@samsung.com> Signed-off-by:
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Anton Altaparmakov authored
commit f2d5a944 upstream. On 32-bit architectures, the legacy buffer_head functions are not always handling the sector number with the proper 64-bit types, and will thus fail on 4TB+ disks. Any code that uses __getblk() (and thus bread(), breadahead(), sb_bread(), sb_breadahead(), sb_getblk()), and calls it using a 64-bit block on a 32-bit arch (where "long" is 32-bit) causes an inifinite loop in __getblk_slow() with an infinite stream of errors logged to dmesg like this: __find_get_block_slow() failed. block=6740375944, b_blocknr=2445408648 b_state=0x00000020, b_size=512 device sda1 blocksize: 512 Note how in hex block is 0x191C1F988 and b_blocknr is 0x91C1F988 i.e. the top 32-bits are missing (in this case the 0x1 at the top). This is because grow_dev_page() is broken and has a 32-bit overflow due to shifting the page index value (a pgoff_t - which is just 32 bits on 32-bit architectures) left-shifted as the block number. But the top bits to get lost as the pgoff_t is not type cast to sector_t / 64-bit before the shift. This patch fixes this issue by type casting "index" to sector_t before doing the left shift. Note this is not a theoretical bug but has been seen in the field on a 4TiB hard drive with logical sector size 512 bytes. This patch has been verified to fix the infinite loop problem on 3.17-rc5 kernel using a 4TB disk image mounted using "-o loop". Without this patch doing a "find /nt" where /nt is an NTFS volume causes the inifinite loop 100% reproducibly whilst with the patch it works fine as expected. Signed-off-by:
Anton Altaparmakov <aia21@cantab.net> Signed-off-by:
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Jiri Olsa authored
commit 4921e320 upstream. The commit '2814eb05 perf kmem: Remove die() calls' disabled 'perf kmem' command for machines without numa support. It made the command fail if '/sys/devices/system/node' dir wasn't found. Skipping the numa based initialization in case the directory is not found and continue execution. Signed-off-by:
Jiri Olsa <jolsa@redhat.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1379003976-5839-5-git-send-email-jolsa@redhat.comSigned-off-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Cc: zhangzhiqiang <zhangzhiqiang.zhang@huawei.com> Signed-off-by:
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Cong Wang authored
commit 3577af70 upstream. We saw a kernel soft lockup in perf_remove_from_context(), it looks like the `perf` process, when exiting, could not go out of the retry loop. Meanwhile, the target process was forking a child. So either the target process should execute the smp function call to deactive the event (if it was running) or it should do a context switch which deactives the event. It seems we optimize out a context switch in perf_event_context_sched_out(), and what's more important, we still test an obsolete task pointer when retrying, so no one actually would deactive that event in this situation. Fix it directly by reloading the task pointer in perf_remove_from_context(). This should cure the above soft lockup. Signed-off-by:
Cong Wang <cwang@twopensource.com> Signed-off-by:
Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Richard Larocque authored
commit 474e941b upstream. Locks the k_itimer's it_lock member when handling the alarm timer's expiry callback. The regular posix timers defined in posix-timers.c have this lock held during timout processing because their callbacks are routed through posix_timer_fn(). The alarm timers follow a different path, so they ought to grab the lock somewhere else. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Signed-off-by:
Richard Larocque <rlarocque@google.com> Signed-off-by:
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Richard Larocque authored
commit 265b81d2 upstream. Avoids sending a signal to alarm timers created with sigev_notify set to SIGEV_NONE by checking for that special case in the timeout callback. The regular posix timers avoid sending signals to SIGEV_NONE timers by not scheduling any callbacks for them in the first place. Although it would be possible to do something similar for alarm timers, it's simpler to handle this as a special case in the timeout. Prior to this patch, the alarm timer would ignore the sigev_notify value and try to deliver signals to the process anyway. Even worse, the sanity check for the value of sigev_signo is skipped when SIGEV_NONE was specified, so the signal number could be bogus. If sigev_signo was an unitialized value (as it often would be if SIGEV_NONE is used), then it's hard to predict which signal will be sent. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Signed-off-by:
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John David Anglin authored
commit d26a7730 upstream. In spite of what the GCC manual says, the -mfast-indirect-calls has never been supported in the 64-bit parisc compiler. Indirect calls have always been done using function descriptors irrespective of the -mfast-indirect-calls option. Recently, it was noticed that a function descriptor was always requested when the -mfast-indirect-calls option was specified. This caused problems when the option was used in application code and doesn't make any sense because the whole point of the option is to avoid using a function descriptor for indirect calls. Fixing this broke 64-bit kernel builds. I will fix GCC but for now we need the attached change. This results in the same kernel code as before. Signed-off-by:
John David Anglin <dave.anglin@bell.net> Signed-off-by:
Helge Deller <deller@gmx.de> Signed-off-by:
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Anton Blanchard authored
commit 85101af1 upstream. ABIv2 kernels are failing to backtrace through the kernel. An example: 39.30% readseek2_proce [kernel.kallsyms] [k] find_get_entry | --- find_get_entry __GI___libc_read The problem is in valid_next_sp() where we check that the new stack pointer is at least STACK_FRAME_OVERHEAD below the previous one. ABIv1 has a minimum stack frame size of 112 bytes consisting of 48 bytes and 64 bytes of parameter save area. ABIv2 changes that to 32 bytes with no paramter save area. STACK_FRAME_OVERHEAD is in theory the minimum stack frame size, but we over 240 uses of it, some of which assume that it includes space for the parameter area. We need to work through all our stack defines and rationalise them but let's fix perf now by creating STACK_FRAME_MIN_SIZE and using in valid_next_sp(). This fixes the issue: 30.64% readseek2_proce [kernel.kallsyms] [k] find_get_entry | --- find_get_entry pagecache_get_page generic_file_read_iter new_sync_read vfs_read sys_read syscall_exit __GI___libc_read Reported-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by:
Anton Blanchard <anton@samba.org> Signed-off-by:
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Wanpeng Li authored
commit 03bd4e1f upstream. The following bug can be triggered by hot adding and removing a large number of xen domain0's vcpus repeatedly: BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 IP: [..] find_busiest_group PGD 5a9d5067 PUD 13067 PMD 0 Oops: 0000 [#3] SMP [...] Call Trace: load_balance ? _raw_spin_unlock_irqrestore idle_balance __schedule schedule schedule_timeout ? lock_timer_base schedule_timeout_uninterruptible msleep lock_device_hotplug_sysfs online_store dev_attr_store sysfs_write_file vfs_write SyS_write system_call_fastpath Last level cache shared mask is built during CPU up and the build_sched_domain() routine takes advantage of it to setup the sched domain CPU topology. However, llc_shared_mask is not released during CPU disable, which leads to an invalid sched domainCPU topology. This patch fix it by releasing the llc_shared_mask correctly during CPU disable. Yasuaki also reported that this can happen on real hardware: https://lkml.org/lkml/2014/7/22/1018 His case is here: == Here is an example on my system. My system has 4 sockets and each socket has 15 cores and HT is enabled. In this case, each core of sockes is numbered as follows: | CPU# Socket#0 | 0-14 , 60-74 Socket#1 | 15-29, 75-89 Socket#2 | 30-44, 90-104 Socket#3 | 45-59, 105-119 Then llc_shared_mask of CPU#30 has 0x3fff80000001fffc0000000. It means that last level cache of Socket#2 is shared with CPU#30-44 and 90-104. When hot-removing socket#2 and #3, each core of sockets is numbered as follows: | CPU# Socket#0 | 0-14 , 60-74 Socket#1 | 15-29, 75-89 But llc_shared_mask is not cleared. So llc_shared_mask of CPU#30 remains having 0x3fff80000001fffc0000000. After that, when hot-adding socket#2 and #3, each core of sockets is numbered as follows: | CPU# Socket#0 | 0-14 , 60-74 Socket#1 | 15-29, 75-89 Socket#2 | 30-59 Socket#3 | 90-119 Then llc_shared_mask of CPU#30 becomes 0x3fff8000fffffffc0000000. It means that last level cache of Socket#2 is shared with CPU#30-59 and 90-104. So the mask has the wrong value. Signed-off-by:
Wanpeng Li <wanpeng.li@linux.intel.com> Tested-by:
Linn Crosetto <linn@hp.com> Reviewed-by:
Borislav Petkov <bp@suse.de> Reviewed-by:
Toshi Kani <toshi.kani@hp.com> Reviewed-by:
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1411547885-48165-1-git-send-email-wanpeng.li@linux.intel.comSigned-off-by:
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Joseph Qi authored
commit 5760a97c upstream. There is a deadlock case which reported by Guozhonghua: https://oss.oracle.com/pipermail/ocfs2-devel/2014-September/010079.html This case is caused by &res->spinlock and &dlm->master_lock misordering in different threads. It was introduced by commit 8d400b81 ("ocfs2/dlm: Clean up refmap helpers"). Since lockres is new, it doesn't not require the &res->spinlock. So remove it. Fixes: 8d400b81 ("ocfs2/dlm: Clean up refmap helpers") Signed-off-by:
Joseph Qi <joseph.qi@huawei.com> Reviewed-by:
joyce.xue <xuejiufei@huawei.com> Reported-by:
Guozhonghua <guozhonghua@h3c.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by:
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Andreas Rohner authored
commit 56d7acc7 upstream. This bug leads to reproducible silent data loss, despite the use of msync(), sync() and a clean unmount of the file system. It is easily reproducible with the following script: ----------------[BEGIN SCRIPT]-------------------- mkfs.nilfs2 -f /dev/sdb mount /dev/sdb /mnt dd if=/dev/zero bs=1M count=30 of=/mnt/testfile umount /mnt mount /dev/sdb /mnt CHECKSUM_BEFORE="$(md5sum /mnt/testfile)" /root/mmaptest/mmaptest /mnt/testfile 30 10 5 sync CHECKSUM_AFTER="$(md5sum /mnt/testfile)" umount /mnt mount /dev/sdb /mnt CHECKSUM_AFTER_REMOUNT="$(md5sum /mnt/testfile)" umount /mnt echo "BEFORE MMAP:\t$CHECKSUM_BEFORE" echo "AFTER MMAP:\t$CHECKSUM_AFTER" echo "AFTER REMOUNT:\t$CHECKSUM_AFTER_REMOUNT" ----------------[END SCRIPT]-------------------- The mmaptest tool looks something like this (very simplified, with error checking removed): ----------------[BEGIN mmaptest]-------------------- data = mmap(NULL, file_size - file_offset, PROT_READ | PROT_WRITE, MAP_SHARED, fd, file_offset); for (i = 0; i < write_count; ++i) { memcpy(data + i * 4096, buf, sizeof(buf)); msync(data, file_size - file_offset, MS_SYNC)) } ----------------[END mmaptest]-------------------- The output of the script looks something like this: BEFORE MMAP: 281ed1d5ae50e8419f9b978aab16de83 /mnt/testfile AFTER MMAP: 6604a1c31f10780331a6850371b3a313 /mnt/testfile AFTER REMOUNT: 281ed1d5ae50e8419f9b978aab16de83 /mnt/testfile So it is clear, that the changes done using mmap() do not survive a remount. This can be reproduced a 100% of the time. The problem was introduced in commit 136e8770 ("nilfs2: fix issue of nilfs_set_page_dirty() for page at EOF boundary"). If the page was read with mpage_readpage() or mpage_readpages() for example, then it has no buffers attached to it. In that case page_has_buffers(page) in nilfs_set_page_dirty() will be false. Therefore nilfs_set_file_dirty() is never called and the pages are never collected and never written to disk. This patch fixes the problem by also calling nilfs_set_file_dirty() if the page has no buffers attached to it. [akpm@linux-foundation.org: s/PAGE_SHIFT/PAGE_CACHE_SHIFT/] Signed-off-by:
Andreas Rohner <andreas.rohner@gmx.net> Tested-by:
Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by:
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Andrey Vagin authored
commit 7e882481 upstream. Currently we handle only ENOSPC. In case of other errors the file_handle variable isn't filled properly and we will show a part of stack. Signed-off-by:
Andrey Vagin <avagin@openvz.org> Acked-by:
Cyrill Gorcunov <gorcunov@openvz.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Andrey Vagin authored
commit 1fc98d11 upstream. MAX_HANDLE_SZ is equal to 128, but currently the size of pad is only 64 bytes, so exportfs_encode_inode_fh can return an error. Signed-off-by:
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