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2017-02-10refcount_t: Introduce a special purpose refcount typePeter Zijlstra
Provide refcount_t, an atomic_t like primitive built just for refcounting. It provides saturation semantics such that overflow becomes impossible and thereby 'spurious' use-after-free is avoided. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-08printk: rename nmi.c and exported apiSergey Senozhatsky
A preparation patch for printk_safe work. No functional change. - rename nmi.c to print_safe.c - add `printk_safe' prefix to some (which used both by printk-safe and printk-nmi) of the exported functions. Link: http://lkml.kernel.org/r/20161227141611.940-3-sergey.senozhatsky@gmail.com Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jan Kara <jack@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Calvin Owens <calvinowens@fb.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
2017-02-06Merge 4.10-rc7 into char-misc-nextGreg Kroah-Hartman
We want the hv and other fixes in here as well to handle merge and testing issues. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-05debugobjects: Reduce contention on the global pool_lockWaiman Long
On a large SMP system with many CPUs, the global pool_lock may become a performance bottleneck as all the CPUs that need to allocate or free debug objects have to take the lock. That can sometimes cause soft lockups like: NMI watchdog: BUG: soft lockup - CPU#35 stuck for 22s! [rcuos/1:21] ... RIP: 0010:[<ffffffff817c216b>] [<ffffffff817c216b>] _raw_spin_unlock_irqrestore+0x3b/0x60 ... Call Trace: [<ffffffff813f40d1>] free_object+0x81/0xb0 [<ffffffff813f4f33>] debug_check_no_obj_freed+0x193/0x220 [<ffffffff81101a59>] ? trace_hardirqs_on_caller+0xf9/0x1c0 [<ffffffff81284996>] ? file_free_rcu+0x36/0x60 [<ffffffff81251712>] kmem_cache_free+0xd2/0x380 [<ffffffff81284960>] ? fput+0x90/0x90 [<ffffffff81284996>] file_free_rcu+0x36/0x60 [<ffffffff81124c23>] rcu_nocb_kthread+0x1b3/0x550 [<ffffffff81124b71>] ? rcu_nocb_kthread+0x101/0x550 [<ffffffff81124a70>] ? sync_exp_work_done.constprop.63+0x50/0x50 [<ffffffff810c59d1>] kthread+0x101/0x120 [<ffffffff81101a59>] ? trace_hardirqs_on_caller+0xf9/0x1c0 [<ffffffff817c2d32>] ret_from_fork+0x22/0x50 To reduce the amount of contention on the pool_lock, the actual kmem_cache_free() of the debug objects will be delayed if the pool_lock is busy. This will temporarily increase the amount of free objects available at the free pool when the system is busy. As a result, the number of kmem_cache allocation and freeing is reduced. To further reduce the lock operations free debug objects in batches of four. Signed-off-by: Waiman Long <longman@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: "Du Changbin" <changbin.du@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jan Stancek <jstancek@redhat.com> Link: http://lkml.kernel.org/r/1483647425-4135-4-git-send-email-longman@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-04debugobjects: Scale thresholds with # of CPUsWaiman Long
On a large SMP systems with hundreds of CPUs, the current thresholds for allocating and freeing debug objects (256 and 1024 respectively) may not work well. This can cause a lot of needless calls to kmem_aloc() and kmem_free() on those systems. To alleviate this thrashing problem, the object freeing threshold is now increased to "1024 + # of CPUs * 32". Whereas the object allocation threshold is increased to "256 + # of CPUs * 4". That should make the debug objects subsystem scale better with the number of CPUs available in the system. Signed-off-by: Waiman Long <longman@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: "Du Changbin" <changbin.du@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jan Stancek <jstancek@redhat.com> Link: http://lkml.kernel.org/r/1483647425-4135-3-git-send-email-longman@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-04debugobjects: Track number of kmem_cache_alloc/kmem_cache_free doneWaiman Long
New debugfs stat counters are added to track the numbers of kmem_cache_alloc() and kmem_cache_free() function calls to get a sense of how the internal debug objects cache management is performing. Signed-off-by: Waiman Long <longman@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: "Du Changbin" <changbin.du@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jan Stancek <jstancek@redhat.com> Link: http://lkml.kernel.org/r/1483647425-4135-2-git-send-email-longman@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-03lib: Introduce priority array area managerJiri Pirko
This introduces a infrastructure for management of linear priority areas. Priority order in an array matters, however order of items inside a priority group does not matter. As an initial implementation, L-sort algorithm is used. It is quite trivial. More advanced algorithm called P-sort will be introduced as a follow-up. The infrastructure is prepared for other algos. Alongside this, a testing module is introduced as well. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-02ext4: move halfmd4 into hash.c directlyJason A. Donenfeld
The "half md4" transform should not be used by any new code. And fortunately, it's only used now by ext4. Since ext4 supports several hashing methods, at some point it might be desirable to move to something like SipHash. As an intermediate step, remove half md4 from cryptohash.h and lib, and make it just a local function in ext4's hash.c. There's precedent for doing this; the other function ext can use for its hashes -- TEA -- is also implemented in the same place. Also, by being a local function, this might allow gcc to perform some additional optimizations. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-02-01Merge tag 'drm-misc-next-2017-01-30' of ↵Dave Airlie
git://anongit.freedesktop.org/git/drm-misc into drm-next Another round of -misc stuff: - Noralf debugfs cleanup cleanup (not yet everything, some more driver patches awaiting acks). - More doc work. - edid/infoframe fixes from Ville. - misc 1-patch fixes all over, as usual Noralf needs this for his tinydrm pull request. * tag 'drm-misc-next-2017-01-30' of git://anongit.freedesktop.org/git/drm-misc: (48 commits) drm/vc4: Remove vc4_debugfs_cleanup() dma/fence: Export enable-signaling tracepoint for emission by drivers drm/tilcdc: Remove tilcdc_debugfs_cleanup() drm/tegra: Remove tegra_debugfs_cleanup() drm/sti: Remove drm_debugfs_remove_files() calls drm/radeon: Remove drm_debugfs_remove_files() call drm/omap: Remove omap_debugfs_cleanup() drm/hdlcd: Remove hdlcd_debugfs_cleanup() drm/etnaviv: Remove etnaviv_debugfs_cleanup() drm/etnaviv: allow build with COMPILE_TEST drm/amd/amdgpu: Remove drm_debugfs_remove_files() call drm/prime: Clarify DMA-BUF/GEM Object lifetime drm/ttm: Make sure BOs being swapped out are cacheable drm/atomic: Remove drm_atomic_debugfs_cleanup() drm: drm_minor_register(): Clean up debugfs on failure drm: debugfs: Remove all files automatically on cleanup drm/fourcc: add vivante tiled layout format modifiers drm/edid: Set YQ bits in the AVI infoframe according to CEA-861-F drm/edid: Set AVI infoframe Q even when QS=0 drm/edid: Introduce drm_hdmi_avi_infoframe_quant_range() ...
2017-01-31Merge branch 'for-mingo' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU changes from Paul E. McKenney: - Dynticks updates, consolidating open-coded counter accesses into a well-defined API - SRCU updates: Simplify algorithm, add formal verification - Documentation updates - Miscellaneous fixes - Torture-test updates Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Two trivial overlapping changes conflicts in MPLS and mlx5. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-27radix tree: constify some pointersMatthew Wilcox
If we're just getting the value of a tag, or looking up an entry, we won't modify the radix tree, so we can declare these functions as taking a const pointer. Mostly for documentation purposes, though it might help code generation. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2017-01-27sbitmap: add helpers for dumping to a seq_fileOmar Sandoval
This is useful debugging information that will be used in the blk-mq debugfs directory. Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Changed 'weight' to 'busy'. Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27Merge branch 'master' of ↵Dave Airlie
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into drm-next Backmerge Linus master to get the connector locking revert. * 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux: (645 commits) sysctl: fix proc_doulongvec_ms_jiffies_minmax() Revert "drm/probe-helpers: Drop locking from poll_enable" MAINTAINERS: add Dan Streetman to zbud maintainers MAINTAINERS: add Dan Streetman to zswap maintainers mm: do not export ioremap_page_range symbol for external module mn10300: fix build error of missing fpu_save() romfs: use different way to generate fsid for BLOCK or MTD frv: add missing atomic64 operations mm, page_alloc: fix premature OOM when racing with cpuset mems update mm, page_alloc: move cpuset seqcount checking to slowpath mm, page_alloc: fix fast-path race with cpuset update or removal mm, page_alloc: fix check for NULL preferred_zone kernel/panic.c: add missing \n fbdev: color map copying bounds checking frv: add atomic64_add_unless() mm/mempolicy.c: do not put mempolicy before using its nodemask radix-tree: fix private list warnings Documentation/filesystems/proc.txt: add VmPin mm, memcg: do not retry precharge charges proc: add a schedule point in proc_pid_readdir() ...
2017-01-25test_firmware: add test custom fallback triggerLuis R. Rodriguez
We have no custom fallback mechanism test interface. Provide one. This tests both the custom fallback mechanism and cancelling the it. Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25test_firmware: use device attribute groupsLuis R. Rodriguez
This simplifies init and exit. Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25test_firmware: move misc_device downLuis R. Rodriguez
This will make further changes easier to review. Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-24mm: do not export ioremap_page_range symbol for external modulezhong jiang
Recently, I've found cases in which ioremap_page_range was used incorrectly, in external modules, leading to crashes. This can be partly attributed to the fact that ioremap_page_range is lower-level, with fewer protections, as compared to the other functions that an external module would typically call. Those include: ioremap_cache ioremap_nocache ioremap_prot ioremap_uc ioremap_wc ioremap_wt ...each of which wraps __ioremap_caller, which in turn provides a safer way to achieve the mapping. Therefore, stop EXPORT-ing ioremap_page_range. Link: http://lkml.kernel.org/r/1485173220-29010-1-git-send-email-zhongjiang@huawei.com Signed-off-by: zhong jiang <zhongjiang@huawei.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Suggested-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-24radix-tree: fix private list warningsMatthew Wilcox
The newly introduced warning in radix_tree_free_nodes() was testing the wrong variable; it should have been 'old' instead of 'node'. Fixes: ea07b862ac8e ("mm: workingset: fix use-after-free in shadow node shrinker") Link: http://lkml.kernel.org/r/20170118163746.GA32495@cmpxchg.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-24lib/dma-virt: Add dma_virt_opsBart Van Assche
Several RDMA drivers (hfi1, qib and rxe) expect that ib_sge.addr is a virtual address. Provide DMA mapping operations that are suitable for these drivers. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-01-24lib/dma-noop: Only build dma_noop_ops for s390 and m32rBart Van Assche
Reduce the kernel size by only building dma_noop_ops for those architectures that actually use it. This was suggested by Christoph Hellwig. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-01-24lib/dma-noop: Clarify a commentBart Van Assche
The next patch in this series will introduce another set of DMA operations that map 1:1 with memory. Clarify that dma-noop maps to physical addresses. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-01-24treewide: Constify most dma_map_ops structuresBart Van Assche
Most dma_map_ops structures are never modified. Constify these structures such that these can be write-protected. This patch has been generated as follows: git grep -l 'struct dma_map_ops' | xargs -d\\n sed -i \ -e 's/struct dma_map_ops/const struct dma_map_ops/g' \ -e 's/const struct dma_map_ops {/struct dma_map_ops {/g' \ -e 's/^const struct dma_map_ops;$/struct dma_map_ops;/' \ -e 's/const const struct dma_map_ops /const struct dma_map_ops /g'; sed -i -e 's/const \(struct dma_map_ops intel_dma_ops\)/\1/' \ $(git grep -l 'struct dma_map_ops intel_dma_ops'); sed -i -e 's/const \(struct dma_map_ops dma_iommu_ops\)/\1/' \ $(git grep -l 'struct dma_map_ops' | grep ^arch/powerpc); sed -i -e '/^struct vmd_dev {$/,/^};$/ s/const \(struct dma_map_ops[[:blank:]]dma_ops;\)/\1/' \ -e '/^static void vmd_setup_dma_ops/,/^}$/ s/const \(struct dma_map_ops \*dest\)/\1/' \ -e 's/const \(struct dma_map_ops \*dest = \&vmd->dma_ops\)/\1/' \ drivers/pci/host/*.c sed -i -e '/^void __init pci_iommu_alloc(void)$/,/^}$/ s/dma_ops->/intel_dma_ops./' arch/ia64/kernel/pci-dma.c sed -i -e 's/static const struct dma_map_ops sn_dma_ops/static struct dma_map_ops sn_dma_ops/' arch/ia64/sn/pci/pci_dma.c sed -i -e 's/(const struct dma_map_ops \*)//' drivers/misc/mic/bus/vop_bus.c Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Russell King <linux@armlinux.org.uk> Cc: x86@kernel.org Signed-off-by: Doug Ledford <dledford@redhat.com>
2017-01-23rcu: Enable RCU tracepoints by default to aid in debuggingMatt Fleming
While debugging a performance issue I needed to understand why RCU sofitrqs were firing so frequently. Unfortunately, the RCU callback tracepoints are hidden behind CONFIG_RCU_TRACE which defaults to off in the upstream kernel and is likely to also be disabled in enterprise distribution configs. Enable it by default for CONFIG_TREE_RCU. However, we must keep it disabled for tiny RCU, because it would otherwise pull in a large amount of code that would make tiny RCU less than tiny. I ran some file system metadata intensive workloads (git checkout, FS-Mark) on a variety of machines with this patch and saw no detectable change in performance. Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2017-01-23lib/prime_numbers: Suppress warn on kmalloc failureChris Wilson
The allocation for the bitmap may become very large, larger than MAX_ORDER, for large requests. We fail gracefully by falling back to trail-division, so disable the warning from kmalloc: 521.961092] WARNING: CPU: 0 PID: 30637 at mm/page_alloc.c:3548 __alloc_pages_slowpath+0x237/0x9a0 [ 521.961105] Modules linked in: i915(+) drm_kms_helper intel_gtt prime_numbers [last unloaded: drm_kms_helper] [ 521.961126] CPU: 0 PID: 30637 Comm: drv_selftest Tainted: G U W 4.10.0-rc3+ #321 [ 521.961137] Hardware name: / , BIOS PYBSWCEL.86A.0027.2015.0507.1758 05/07/2015 [ 521.961148] Call Trace: [ 521.961161] dump_stack+0x4d/0x6f [ 521.961172] __warn+0xc1/0xe0 [ 521.961181] warn_slowpath_null+0x18/0x20 [ 521.961189] __alloc_pages_slowpath+0x237/0x9a0 [ 521.961200] ? sg_init_table+0x1a/0x40 [ 521.961208] ? get_page_from_freelist+0x3fa/0x910 [ 521.961275] ? i915_gem_object_get_sg+0x272/0x2b0 [i915] [ 521.961285] __alloc_pages_nodemask+0x1ea/0x220 [ 521.961295] kmalloc_order+0x1c/0x50 [ 521.961304] __kmalloc+0x115/0x170 [ 521.961314] expand_to_next_prime+0x43/0x180 [prime_numbers] [ 521.961324] next_prime_number+0x47/0xc0 [prime_numbers] [ 521.961377] igt_vma_rotate+0x386/0x590 [i915] [ 521.961429] i915_subtests+0x37/0xc0 [i915] [ 521.961481] i915_vma_mock_selftests+0x3d/0x70 [i915] [ 521.961532] run_selftests+0x16e/0x1f0 [i915] [ 521.961541] ? 0xffffffffa02a4000 [ 521.961592] i915_mock_selftests+0x29/0x40 [i915] [ 521.961638] i915_init+0xa/0x5e [i915] [ 521.961646] ? 0xffffffffa02a4000 [ 521.961655] do_one_initcall+0x3e/0x160 [ 521.961664] ? __vunmap+0x7c/0xc0 [ 521.961672] ? vfree+0x29/0x70 [ 521.961680] ? kmem_cache_alloc+0xcf/0x120 [ 521.961690] do_init_module+0x55/0x1c4 [ 521.961699] load_module+0x1f3f/0x25b0 [ 521.961707] ? __symbol_put+0x40/0x40 [ 521.961716] ? kernel_read_file+0x100/0x190 [ 521.961725] SYSC_finit_module+0xbc/0xf0 [ 521.961734] SyS_finit_module+0x9/0x10 [ 521.961744] entry_SYSCALL_64_fastpath+0x17/0x98 [ 521.961752] RIP: 0033:0x7f111aca4119 [ 521.961760] RSP: 002b:00007ffd8be6cbe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 521.961773] RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f111aca4119 [ 521.961781] RDX: 0000000000000000 RSI: 000055dfc18bc8e0 RDI: 0000000000000006 [ 521.961789] RBP: 00007ffd8be6bbe0 R08: 0000000000000000 R09: 0000000000000000 [ 521.961796] R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000005 [ 521.961805] R13: 000055dfc18bd3a0 R14: 00007ffd8be6bbc0 R15: 0000000000000005 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/20170113235119.22528-1-chris@chris-wilson.co.uk
2017-01-20percpu_counter: percpu_counter_hotcpu_callback() cleanupEric Dumazet
In commit ebd8fef304f9 ("percpu_counter: make percpu_counters_lock irq-safe") we disabled irqs in percpu_counter_hotcpu_callback() We can grab every counter spinlock without having to disable irqs again. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-01-20timerqueue: Use rb_entry_safe() instead of open-coding itGeliang Tang
Signed-off-by: Geliang Tang <geliangtang@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/0d5cf199ac43792df0b6f7e2145545c30fa1dbbe.1482222135.git.geliangtang@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-18sbitmap: fix wakeup hang after sbq resizeOmar Sandoval
When we resize a struct sbitmap_queue, we update the wakeup batch size, but we don't update the wait count in the struct sbq_wait_states. If we resized down from a size which could use a bigger batch size, these counts could be too large and cause us to miss necessary wakeups. To fix this, update the wait counts when we resize (ensuring some careful memory ordering so that it's safe w.r.t. concurrent clears). This also fixes a theoretical issue where two threads could end up bumping the wait count up by the batch size, which could also potentially lead to hangs. Reported-by: Martin Raiber <martin@urbackup.org> Fixes: e3a2b3f931f5 ("blk-mq: allow changing of queue depth through sysfs") Fixes: 2971c35f3588 ("blk-mq: bitmap tag: fix race on blk_mq_bitmap_tags::wake_cnt") Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-18sbitmap: use smp_mb__after_atomic() in sbq_wake_up()Omar Sandoval
We always do an atomic clear_bit() right before we call sbq_wake_up(), so we can use smp_mb__after_atomic(). While we're here, comment the memory barriers in here a little more. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2017-01-17Merge branch 'stable/for-linus-4.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb Pull swiotlb fix from Konrad Rzeszutek Wilk: "A tiny fix to make sure that page-sized mappings are page-aligned (and not say straddle two pages). This is important for some drivers (such as NVME)" * 'stable/for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: swiotlb: ensure that page-sized mappings are page-aligned
2017-01-16Merge 4.10-rc4 into tty-nextGreg Kroah-Hartman
We want the serial/tty fixes in here as well to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-15swiotlb: ensure that page-sized mappings are page-alignedNikita Yushchenko
Some drivers do depend on page mappings to be page aligned. Swiotlb already enforces such alignment for mappings greater than page, extend that to page-sized mappings as well. Without this fix, nvme hits BUG() in nvme_setup_prps(), because that routine assumes page-aligned mappings. Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
2017-01-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs fixes from Al Viro. The most notable fix here is probably the fix for a splice regression ("fix a fencepost error in pipe_advance()") noticed by Alan Wylie. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix a fencepost error in pipe_advance() coredump: Ensure proper size of sparse core files aio: fix lock dep warning tmpfs: clear S_ISGID when setting posix ACLs
2017-01-14fix a fencepost error in pipe_advance()Al Viro
The logics in pipe_advance() used to release all buffers past the new position failed in cases when the number of buffers to release was equal to pipe->buffers. If that happened, none of them had been released, leaving pipe full. Worse, it was trivial to trigger and we end up with pipe full of uninitialized pages. IOW, it's an infoleak. Cc: stable@vger.kernel.org # v4.9 Reported-by: "Alan J. Wylie" <alan@wylie.me.uk> Tested-by: "Alan J. Wylie" <alan@wylie.me.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-01-14locking/ww_mutex: Begin kselftests for ww_mutexChris Wilson
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maarten Lankhorst <dev@mblankhorst.nl> Cc: Nicolai Hähnle <nhaehnle@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161201114711.28697-4-chris@chris-wilson.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-12Merge branch 'aarch64/for-next/debug-virtual' into aarch64/for-next/coreWill Deacon
Merge core DEBUG_VIRTUAL changes from Laura Abbott. Later arm and arm64 support depends on these. * aarch64/for-next/debug-virtual: drivers: firmware: psci: Use __pa_symbol for kernel symbol mm/usercopy: Switch to using lm_alias mm/kasan: Switch to using __pa_symbol and lm_alias kexec: Switch to __pa_symbol mm: Introduce lm_alias mm/cma: Cleanup highmem check lib/Kconfig.debug: Add ARCH_HAS_DEBUG_VIRTUAL
2017-01-12serial: do not accept sysrq characters via serial portFelix Fietkau
many embedded boards have a disconnected TTL level serial which can generate some garbage that can lead to spurious false sysrq detects. Signed-off-by: John Crispin <john@phrozen.org> Signed-off-by: Felix Fietkau <nbd@nbd.name> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Two AF_* families adding entries to the lockdep tables at the same time. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-11lib/Kconfig.debug: Add ARCH_HAS_DEBUG_VIRTUALLaura Abbott
DEBUG_VIRTUAL currently depends on DEBUG_KERNEL && X86. arm64 is getting the same support. Rather than add a list of architectures, switch this to ARCH_HAS_DEBUG_VIRTUAL and let architectures select it as appropriate. Acked-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-10lib/Kconfig.debug: fix frv build failureSudip Mukherjee
The build of frv allmodconfig was failing with the errors like: /tmp/cc0JSPc3.s: Assembler messages: /tmp/cc0JSPc3.s:1839: Error: symbol `.LSLT0' is already defined /tmp/cc0JSPc3.s:1842: Error: symbol `.LASLTP0' is already defined /tmp/cc0JSPc3.s:1969: Error: symbol `.LELTP0' is already defined /tmp/cc0JSPc3.s:1970: Error: symbol `.LELT0' is already defined Commit 866ced950bcd ("kbuild: Support split debug info v4") introduced splitting the debug info and keeping that in a separate file. Somehow, the frv-linux gcc did not like that and I am guessing that instead of splitting it started copying. The first report about this is at: https://lists.01.org/pipermail/kbuild-all/2015-July/010527.html. I will try and see if this can work with frv and if still fails I will open a bug report with gcc. But meanwhile this is the easiest option to solve build failure of frv. Fixes: 866ced950bcd ("kbuild: Support split debug info v4") Link: http://lkml.kernel.org/r/1482062348-5352-1-git-send-email-sudipm.mukherjee@gmail.com Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2017-01-09siphash: implement HalfSipHash1-3 for hash tablesJason A. Donenfeld
HalfSipHash, or hsiphash, is a shortened version of SipHash, which generates 32-bit outputs using a weaker 64-bit key. It has *much* lower security margins, and shouldn't be used for anything too sensitive, but it could be used as a hashtable key function replacement, if the output is never exposed, and if the security requirement is not too high. The goal is to make this something that performance-critical jhash users would be willing to use. On 64-bit machines, HalfSipHash1-3 is slower than SipHash1-3, so we alias SipHash1-3 to HalfSipHash1-3 on those systems. 64-bit x86_64: [ 0.509409] test_siphash: SipHash2-4 cycles: 4049181 [ 0.510650] test_siphash: SipHash1-3 cycles: 2512884 [ 0.512205] test_siphash: HalfSipHash1-3 cycles: 3429920 [ 0.512904] test_siphash: JenkinsHash cycles: 978267 So, we map hsiphash() -> SipHash1-3 32-bit x86: [ 0.509868] test_siphash: SipHash2-4 cycles: 14812892 [ 0.513601] test_siphash: SipHash1-3 cycles: 9510710 [ 0.515263] test_siphash: HalfSipHash1-3 cycles: 3856157 [ 0.515952] test_siphash: JenkinsHash cycles: 1148567 So, we map hsiphash() -> HalfSipHash1-3 hsiphash() is roughly 3 times slower than jhash(), but comes with a considerable security improvement. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-09siphash: add cryptographically secure PRFJason A. Donenfeld
SipHash is a 64-bit keyed hash function that is actually a cryptographically secure PRF, like HMAC. Except SipHash is super fast, and is meant to be used as a hashtable keyed lookup function, or as a general PRF for short input use cases, such as sequence numbers or RNG chaining. For the first usage: There are a variety of attacks known as "hashtable poisoning" in which an attacker forms some data such that the hash of that data will be the same, and then preceeds to fill up all entries of a hashbucket. This is a realistic and well-known denial-of-service vector. Currently hashtables use jhash, which is fast but not secure, and some kind of rotating key scheme (or none at all, which isn't good). SipHash is meant as a replacement for jhash in these cases. There are a modicum of places in the kernel that are vulnerable to hashtable poisoning attacks, either via userspace vectors or network vectors, and there's not a reliable mechanism inside the kernel at the moment to fix it. The first step toward fixing these issues is actually getting a secure primitive into the kernel for developers to use. Then we can, bit by bit, port things over to it as deemed appropriate. While SipHash is extremely fast for a cryptographically secure function, it is likely a bit slower than the insecure jhash, and so replacements will be evaluated on a case-by-case basis based on whether or not the difference in speed is negligible and whether or not the current jhash usage poses a real security risk. For the second usage: A few places in the kernel are using MD5 or SHA1 for creating secure sequence numbers, syn cookies, port numbers, or fast random numbers. SipHash is a faster and more fitting, and more secure replacement for MD5 in those situations. Replacing MD5 and SHA1 with SipHash for these uses is obvious and straight-forward, and so is submitted along with this patch series. There shouldn't be much of a debate over its efficacy. Dozens of languages are already using this internally for their hash tables and PRFs. Some of the BSDs already use this in their kernels. SipHash is a widely known high-speed solution to a widely known set of problems, and it's time we catch-up. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-09Merge tag 'drm-misc-next-2016-12-30' of ↵Dave Airlie
git://anongit.freedesktop.org/git/drm-misc into drm-next First -misc pull for 4.11: - drm_mm rework + lots of selftests (Chris Wilson) - new connector_list locking+iterators - plenty of kerneldoc updates - format handling rework from Ville - atomic helper changes from Maarten for better plane corner-case handling in drivers, plus the i915 legacy cursor patch that needs this - bridge cleanup from Laurent - plus plenty of small stuff all over - also contains a merge of the 4.10 docs tree so that we could apply the dma-buf kerneldoc patches It's a lot more than usual, but due to the merge window blackout it also covers about 4 weeks, so all in line again on a per-week basis. The more annoying part with no pull request for 4 weeks is managing cross-tree work. The -intel pull request I'll follow up with does conflict quite a bit with -misc here. Longer-term (if drm-misc keeps growing) a drm-next-queued to accept pull request for the next merge window during this time might be useful. I'd also like to backmerge -rc2+this into drm-intel next week, we have quite a pile of patches waiting for the stuff in here. * tag 'drm-misc-next-2016-12-30' of git://anongit.freedesktop.org/git/drm-misc: (126 commits) drm: Add kerneldoc markup for new @scan parameters in drm_mm drm/mm: Document locking rules drm: Use drm_mm_insert_node_in_range_generic() for everyone drm: Apply range restriction after color adjustment when allocation drm: Wrap drm_mm_node.hole_follows drm: Apply tight eviction scanning to color_adjust drm: Simplify drm_mm scan-list manipulation drm: Optimise power-of-two alignments in drm_mm_scan_add_block() drm: Compute tight evictions for drm_mm_scan drm: Fix application of color vs range restriction when scanning drm_mm drm: Unconditionally do the range check in drm_mm_scan_add_block() drm: Rename prev_node to hole in drm_mm_scan_add_block() drm: Fix O= out-of-tree builds for selftests drm: Extract struct drm_mm_scan from struct drm_mm drm: Add asserts to catch overflow in drm_mm_init() and drm_mm_init_scan() drm: Simplify drm_mm_clean() drm: Detect overflow in drm_mm_reserve_node() drm: Fix kerneldoc for drm_mm_scan_remove_block() drm: Promote drm_mm alignment to u64 drm: kselftest for drm_mm and restricted color eviction ...
2017-01-07mm: workingset: fix use-after-free in shadow node shrinkerJohannes Weiner
Several people report seeing warnings about inconsistent radix tree nodes followed by crashes in the workingset code, which all looked like use-after-free access from the shadow node shrinker. Dave Jones managed to reproduce the issue with a debug patch applied, which confirmed that the radix tree shrinking indeed frees shadow nodes while they are still linked to the shadow LRU: WARNING: CPU: 2 PID: 53 at lib/radix-tree.c:643 delete_node+0x1e4/0x200 CPU: 2 PID: 53 Comm: kswapd0 Not tainted 4.10.0-rc2-think+ #3 Call Trace: delete_node+0x1e4/0x200 __radix_tree_delete_node+0xd/0x10 shadow_lru_isolate+0xe6/0x220 __list_lru_walk_one.isra.4+0x9b/0x190 list_lru_walk_one+0x23/0x30 scan_shadow_nodes+0x2e/0x40 shrink_slab.part.44+0x23d/0x5d0 shrink_node+0x22c/0x330 kswapd+0x392/0x8f0 This is the WARN_ON_ONCE(!list_empty(&node->private_list)) placed in the inlined radix_tree_shrink(). The problem is with 14b468791fa9 ("mm: workingset: move shadow entry tracking to radix tree exceptional tracking"), which passes an update callback into the radix tree to link and unlink shadow leaf nodes when tree entries change, but forgot to pass the callback when reclaiming a shadow node. While the reclaimed shadow node itself is unlinked by the shrinker, its deletion from the tree can cause the left-most leaf node in the tree to be shrunk. If that happens to be a shadow node as well, we don't unlink it from the LRU as we should. Consider this tree, where the s are shadow entries: root->rnode | [0 n] | | [s ] [sssss] Now the shadow node shrinker reclaims the rightmost leaf node through the shadow node LRU: root->rnode | [0 ] | [s ] Because the parent of the deleted node is the first level below the root and has only one child in the left-most slot, the intermediate level is shrunk and the node containing the single shadow is put in its place: root->rnode | [s ] The shrinker again sees a single left-most slot in a first level node and thus decides to store the shadow in root->rnode directly and free the node - which is a leaf node on the shadow node LRU. root->rnode | s Without the update callback, the freed node remains on the shadow LRU, where it causes later shrinker runs to crash. Pass the node updater callback into __radix_tree_delete_node() in case the deletion causes the left-most branch in the tree to collapse too. Also add warnings when linked nodes are freed right away, rather than wait for the use-after-free when the list is scanned much later. Fixes: 14b468791fa9 ("mm: workingset: move shadow entry tracking to radix tree exceptional tracking") Reported-by: Dave Chinner <david@fromorbit.com> Reported-by: Hugh Dickins <hughd@google.com> Reported-by: Andrea Arcangeli <aarcange@redhat.com> Reported-and-tested-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Chris Leech <cleech@redhat.com> Cc: Lee Duncan <lduncan@suse.com> Cc: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <mawilcox@linuxonhyperv.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-06Merge branch 'stable/for-linus-4.10' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb Pull swiotlb fixes from Konrad Rzeszutek Wilk: "This has one fix to make i915 work when using Xen SWIOTLB, and a feature from Geert to aid in debugging of devices that can't do DMA outside the 32-bit address space. The feature from Geert is on top of v4.10 merge window commit (specifically you pulling my previous branch), as his changes were dependent on the Documentation/ movement patches. I figured it would just easier than me trying than to cherry-pick the Documentation patches to satisfy git. The patches have been soaking since 12/20, albeit I updated the last patch due to linux-next catching an compiler error and adding an Tested-and-Reported-by tag" * 'stable/for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: swiotlb: Export swiotlb_max_segment to users swiotlb: Add swiotlb=noforce debug option swiotlb: Convert swiotlb_force from int to enum x86, swiotlb: Simplify pci_swiotlb_detect_override()
2017-01-06swiotlb: Export swiotlb_max_segment to usersKonrad Rzeszutek Wilk
So they can figure out what is the optimal number of pages that can be contingously stitched together without fear of bounce buffer. We also expose an mechanism for sub-users of SWIOTLB API, such as Xen-SWIOTLB to set the max segment value. And lastly if swiotlb=force is set (which mandates we bounce buffer everything) we set max_segment so at least we can bounce buffer one 4K page instead of a giant 512KB one for which we may not have space. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reported-and-Tested-by: Juergen Gross <jgross@suse.com>
2016-12-27lib: Add a simple prime number generatorChris Wilson
Prime numbers are interesting for testing components that use multiplies and divides, such as testing DRM's struct drm_mm alignment computations. v2: Move to lib/, add selftest v3: Fix initial constants (exclude 0/1 from being primes) v4: More RCU markup to keep 0day/sparse happy v5: Fix RCU unwind on module exit, add to kselftests v6: Tidy computation of bitmap size v7: for_each_prime_number_from() v8: Compose small-primes using BIT() for easier verification v9: Move rcu dance entirely into callers. v10: Improve quote for Betrand's Postulate (aka Chebyshev's theorem) Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Lukas Wunner <lukas@wunner.de> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/20161222144514.3911-1-chris@chris-wilson.co.uk
2016-12-25Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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