linux/include, branch v3.4.80

sched/rt: Avoid updating RT entry timeout twice within one tick period

2014-02-13T19:51:19Z

commit 57d2aa00dcec67afa52478730f2b524521af14fb upstream. The issue below was found in 2.6.34-rt rather than mainline rt kernel, but the issue still exists upstream as well. So please let me describe how it was noticed on 2.6.34-rt: On this version, each softirq has its own thread, it means there is at least one RT FIFO task per cpu. The priority of these tasks is set to 49 by default. If user launches an RT FIFO task with priority lower than 49 of softirq RT tasks, it's possible there are two RT FIFO tasks enqueued one cpu runqueue at one moment. By current strategy of balancing RT tasks, when it comes to RT tasks, we really need to put them off to a CPU that they can run on as soon as possible. Even if it means a bit of cache line flushing, we want RT tasks to be run with the least latency. When the user RT FIFO task which just launched before is running, the sched timer tick of the current cpu happens. In this tick period, the timeout value of the user RT task will be updated once. Subsequently, we try to wake up one softirq RT task on its local cpu. As the priority of current user RT task is lower than the softirq RT task, the current task will be preempted by the higher priority softirq RT task. Before preemption, we check to see if current can readily move to a different cpu. If so, we will reschedule to allow the RT push logic to try to move current somewhere else. Whenever the woken softirq RT task runs, it first tries to migrate the user FIFO RT task over to a cpu that is running a task of lesser priority. If migration is done, it will send a reschedule request to the found cpu by IPI interrupt. Once the target cpu responds the IPI interrupt, it will pick the migrated user RT task to preempt its current task. When the user RT task is running on the new cpu, the sched timer tick of the cpu fires. So it will tick the user RT task again. This also means the RT task timeout value will be updated again. As the migration may be done in one tick period, it means the user RT task timeout value will be updated twice within one tick. If we set a limit on the amount of cpu time for the user RT task by setrlimit(RLIMIT_RTTIME), the SIGXCPU signal should be posted upon reaching the soft limit. But exactly when the SIGXCPU signal should be sent depends on the RT task timeout value. In fact the timeout mechanism of sending the SIGXCPU signal assumes the RT task timeout is increased once every tick. However, currently the timeout value may be added twice per tick. So it results in the SIGXCPU signal being sent earlier than expected. To solve this issue, we prevent the timeout value from increasing twice within one tick time by remembering the jiffies value of last updating the timeout. As long as the RT task's jiffies is different with the global jiffies value, we allow its timeout to be updated. Signed-off-by: Ying Xue Signed-off-by: Fan Du Reviewed-by: Yong Zhang Acked-by: Steven Rostedt Cc: Link: http://lkml.kernel.org/r/1342508623-2887-1-git-send-email-ying.xue@windriver.com Signed-off-by: Ingo Molnar [ lizf: backported to 3.4: adjust context ] Signed-off-by: Li Zefan Signed-off-by: Greg Kroah-Hartman

ore: Fix wrong math in allocation of per device BIO

2014-02-13T19:51:11Z

commit aad560b7f63b495f48a7232fd086c5913a676e6f upstream. At IO preparation we calculate the max pages at each device and allocate a BIO per device of that size. The calculation was wrong on some unaligned corner cases offset/length combination and would make prepare return with -ENOMEM. This would be bad for pnfs-objects that would in that case IO through MDS. And fatal for exofs were it would fail writes with EIO. Fix it by doing the proper math, that will work in all cases. (I ran a test with all possible offset/length combinations this time round). Also when reading we do not need to allocate for the parity units since we jump over them. Also lower the max_io_length to take into account the parity pages so not to allocate BIOs bigger than PAGE_SIZE Signed-off-by: Boaz Harrosh Signed-off-by: Greg Kroah-Hartman

audit: correct a type mismatch in audit_syscall_exit()

2014-02-13T19:51:08Z

commit 06bdadd7634551cfe8ce071fe44d0311b3033d9e upstream. audit_syscall_exit() saves a result of regs_return_value() in intermediate "int" variable and passes it to __audit_syscall_exit(), which expects its second argument as a "long" value. This will result in truncating the value returned by a system call and making a wrong audit record. I don't know why gcc compiler doesn't complain about this, but anyway it causes a problem at runtime on arm64 (and probably most 64-bit archs). Signed-off-by: AKASHI Takahiro Cc: Al Viro Cc: Eric Paris Signed-off-by: Andrew Morton Signed-off-by: Eric Paris Signed-off-by: Greg Kroah-Hartman

mm: hugetlbfs: fix hugetlbfs optimization

2014-02-06T19:05:46Z

commit 27c73ae759774e63313c1fbfeb17ba076cea64c5 upstream. Commit 7cb2ef56e6a8 ("mm: fix aio performance regression for database caused by THP") can cause dereference of a dangling pointer if split_huge_page runs during PageHuge() if there are updates to the tail_page->private field. Also it is repeating compound_head twice for hugetlbfs and it is running compound_head+compound_trans_head for THP when a single one is needed in both cases. The new code within the PageSlab() check doesn't need to verify that the THP page size is never bigger than the smallest hugetlbfs page size, to avoid memory corruption. A longstanding theoretical race condition was found while fixing the above (see the change right after the skip_unlock label, that is relevant for the compound_lock path too). By re-establishing the _mapcount tail refcounting for all compound pages, this also fixes the below problem: echo 0 >/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages BUG: Bad page state in process bash pfn:59a01 page:ffffea000139b038 count:0 mapcount:10 mapping: (null) index:0x0 page flags: 0x1c00000000008000(tail) Modules linked in: CPU: 6 PID: 2018 Comm: bash Not tainted 3.12.0+ #25 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x55/0x76 bad_page+0xd5/0x130 free_pages_prepare+0x213/0x280 __free_pages+0x36/0x80 update_and_free_page+0xc1/0xd0 free_pool_huge_page+0xc2/0xe0 set_max_huge_pages.part.58+0x14c/0x220 nr_hugepages_store_common.isra.60+0xd0/0xf0 nr_hugepages_store+0x13/0x20 kobj_attr_store+0xf/0x20 sysfs_write_file+0x189/0x1e0 vfs_write+0xc5/0x1f0 SyS_write+0x55/0xb0 system_call_fastpath+0x16/0x1b Signed-off-by: Khalid Aziz Signed-off-by: Andrea Arcangeli Tested-by: Khalid Aziz Cc: Pravin Shelar Cc: Greg Kroah-Hartman Cc: Ben Hutchings Cc: Christoph Lameter Cc: Johannes Weiner Cc: Mel Gorman Cc: Rik van Riel Cc: Andi Kleen Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Guillaume Morin Signed-off-by: Greg Kroah-Hartman

vlan: Fix header ops passthru when doing TX VLAN offload.

2014-01-15T23:27:11Z

[ Upstream commit 2205369a314e12fcec4781cc73ac9c08fc2b47de ] When the vlan code detects that the real device can do TX VLAN offloads in hardware, it tries to arrange for the real device's header_ops to be invoked directly. But it does so illegally, by simply hooking the real device's header_ops up to the VLAN device. This doesn't work because we will end up invoking a set of header_ops routines which expect a device type which matches the real device, but will see a VLAN device instead. Fix this by providing a pass-thru set of header_ops which will arrange to pass the proper real device instead. To facilitate this add a dev_rebuild_header(). There are implementations which provide a ->cache and ->create but not a ->rebuild (f.e. PLIP). So we need a helper function just like dev_hard_header() to avoid crashes. Use this helper in the one existing place where the header_ops->rebuild was being invoked, the neighbour code. With lots of help from Florian Westphal. Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: unix: allow set_peek_off to fail

2014-01-15T23:27:11Z

[ Upstream commit 12663bfc97c8b3fdb292428105dd92d563164050 ] unix_dgram_recvmsg() will hold the readlock of the socket until recv is complete. In the same time, we may try to setsockopt(SO_PEEK_OFF) which will hang until unix_dgram_recvmsg() will complete (which can take a while) without allowing us to break out of it, triggering a hung task spew. Instead, allow set_peek_off to fail, this way userspace will not hang. Signed-off-by: Sasha Levin Acked-by: Pavel Emelyanov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

drm/radeon: 0x9649 is SUMO2 not SUMO

2014-01-08T17:42:11Z

commit d00adcc8ae9e22eca9d8af5f66c59ad9a74c90ec upstream. Fixes rendering corruption due to incorrect gfx configuration. bug: https://bugs.freedesktop.org/show_bug.cgi?id=63599 Signed-off-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman

ALSA: memalloc.h - fix wrong truncation of dma_addr_t

2013-12-20T15:34:19Z

commit 932e9dec380c67ec15ac3eb073bb55797d8b4801 upstream. When running a 32bit kernel the hda_intel driver is still reporting a 64bit dma_mask if the HW supports it. From sound/pci/hda/hda_intel.c: /* allow 64bit DMA address if supported by H/W */ if ((gcap & ICH6_GCAP_64OK) && !pci_set_dma_mask(pci, DMA_BIT_MASK(64))) pci_set_consistent_dma_mask(pci, DMA_BIT_MASK(64)); else { pci_set_dma_mask(pci, DMA_BIT_MASK(32)); pci_set_consistent_dma_mask(pci, DMA_BIT_MASK(32)); } which means when there is a call to dma_alloc_coherent from snd_malloc_dev_pages a machine address bigger than 32bit can be returned. This can be true in particular if running the 32bit kernel as a pv dom0 under the Xen Hypervisor or PAE on bare metal. The problem is that when calling setup_bdle to program the BLE the dma_addr_t returned from the dma_alloc_coherent is wrongly truncated from snd_sgbuf_get_addr if running a 32bit kernel: static inline dma_addr_t snd_sgbuf_get_addr(struct snd_dma_buffer *dmab, size_t offset) { struct snd_sg_buf *sgbuf = dmab->private_data; dma_addr_t addr = sgbuf->table[offset >> PAGE_SHIFT].addr; addr &= PAGE_MASK; return addr + offset % PAGE_SIZE; } where PAGE_MASK in a 32bit kernel is zeroing the upper 32bit af addr. Without this patch the HW will fetch the 32bit truncated address, which is not the one obtained from dma_alloc_coherent and will result to a non working audio but can corrupt host memory at a random location. The current patch apply to v3.13-rc3-74-g6c843f5 Signed-off-by: Stefano Panella Reviewed-by: Frediano Ziglio Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman

crypto: scatterwalk - Use sg_chain_ptr on chain entries

2013-12-12T06:34:12Z

commit 389a5390583a18e45bc4abd4439291abec5e7a63 upstream. Now that scatterwalk_sg_chain sets the chain pointer bit the sg_page call in scatterwalk_sg_next hits a BUG_ON when CONFIG_DEBUG_SG is enabled. Use sg_chain_ptr instead of sg_page on a chain entry. Signed-off-by: Tom Lendacky Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: scatterwalk - Set the chain pointer indication bit

2013-12-12T06:34:10Z

commit 41da8b5adba77e22584f8b45f9641504fa885308 upstream. The scatterwalk_crypto_chain function invokes the scatterwalk_sg_chain function to chain two scatterlists, but the chain pointer indication bit is not set. When the resulting scatterlist is used, for example, by sg_nents to count the number of scatterlist entries, a segfault occurs because sg_nents does not follow the chain pointer to the chained scatterlist. Update scatterwalk_sg_chain to set the chain pointer indication bit as is done by the sg_chain function. Signed-off-by: Tom Lendacky Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman