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2015-05-11Btrfs: fix race when reusing stale extent buffers that leads to BUG_ONFilipe Manana
There's a race between releasing extent buffers that are flagged as stale and recycling them that makes us it the following BUG_ON at btrfs_release_extent_buffer_page: BUG_ON(extent_buffer_under_io(eb)) The BUG_ON is triggered because the extent buffer has the flag EXTENT_BUFFER_DIRTY set as a consequence of having been reused and made dirty by another concurrent task. Here follows a sequence of steps that leads to the BUG_ON. CPU 0 CPU 1 CPU 2 path->nodes[0] == eb X X->refs == 2 (1 for the tree, 1 for the path) btrfs_header_generation(X) == current trans id flag EXTENT_BUFFER_DIRTY set on X btrfs_release_path(path) unlocks X reads eb X X->refs incremented to 3 locks eb X btrfs_del_items(X) X becomes empty clean_tree_block(X) clear EXTENT_BUFFER_DIRTY from X btrfs_del_leaf(X) unlocks X extent_buffer_get(X) X->refs incremented to 4 btrfs_free_tree_block(X) X's range is not pinned X's range added to free space cache free_extent_buffer_stale(X) lock X->refs_lock set EXTENT_BUFFER_STALE on X release_extent_buffer(X) X->refs decremented to 3 unlocks X->refs_lock btrfs_release_path() unlocks X free_extent_buffer(X) X->refs becomes 2 __btrfs_cow_block(Y) btrfs_alloc_tree_block() btrfs_reserve_extent() find_free_extent() gets offset == X->start btrfs_init_new_buffer(X->start) btrfs_find_create_tree_block(X->start) alloc_extent_buffer(X->start) find_extent_buffer(X->start) finds eb X in radix tree free_extent_buffer(X) lock X->refs_lock test X->refs == 2 test bit EXTENT_BUFFER_STALE is set test !extent_buffer_under_io(eb) increments X->refs to 3 mark_extent_buffer_accessed(X) check_buffer_tree_ref(X) --> does nothing, X->refs >= 2 and EXTENT_BUFFER_TREE_REF is set in X clear EXTENT_BUFFER_STALE from X locks X btrfs_mark_buffer_dirty() set_extent_buffer_dirty(X) check_buffer_tree_ref(X) --> does nothing, X->refs >= 2 and EXTENT_BUFFER_TREE_REF is set sets EXTENT_BUFFER_DIRTY on X test and clear EXTENT_BUFFER_TREE_REF decrements X->refs to 2 release_extent_buffer(X) decrements X->refs to 1 unlock X->refs_lock unlock X free_extent_buffer(X) lock X->refs_lock release_extent_buffer(X) decrements X->refs to 0 btrfs_release_extent_buffer_page(X) BUG_ON(extent_buffer_under_io(X)) --> EXTENT_BUFFER_DIRTY set on X Fix this by making find_extent buffer wait for any ongoing task currently executing free_extent_buffer()/free_extent_buffer_stale() if the extent buffer has the stale flag set. A more clean alternative would be to always increment the extent buffer's reference count while holding its refs_lock spinlock but find_extent_buffer is a performance critical area and that would cause lock contention whenever multiple tasks search for the same extent buffer concurrently. A build server running a SLES 12 kernel (3.12 kernel + over 450 upstream btrfs patches backported from newer kernels) was hitting this often: [1212302.461948] kernel BUG at ../fs/btrfs/extent_io.c:4507! (...) [1212302.470219] CPU: 1 PID: 19259 Comm: bs_sched Not tainted 3.12.36-38-default #1 [1212302.540792] Hardware name: Supermicro PDSM4/PDSM4, BIOS 6.00 04/17/2006 [1212302.540792] task: ffff8800e07e0100 ti: ffff8800d6412000 task.ti: ffff8800d6412000 [1212302.540792] RIP: 0010:[<ffffffffa0507081>] [<ffffffffa0507081>] btrfs_release_extent_buffer_page.constprop.51+0x101/0x110 [btrfs] (...) [1212302.630008] Call Trace: [1212302.630008] [<ffffffffa05070cd>] release_extent_buffer+0x3d/0xa0 [btrfs] [1212302.630008] [<ffffffffa04c2d9d>] btrfs_release_path+0x1d/0xa0 [btrfs] [1212302.630008] [<ffffffffa04c5c7e>] read_block_for_search.isra.33+0x13e/0x3a0 [btrfs] [1212302.630008] [<ffffffffa04c8094>] btrfs_search_slot+0x3f4/0xa80 [btrfs] [1212302.630008] [<ffffffffa04cf5d8>] lookup_inline_extent_backref+0xf8/0x630 [btrfs] [1212302.630008] [<ffffffffa04d13dd>] __btrfs_free_extent+0x11d/0xc40 [btrfs] [1212302.630008] [<ffffffffa04d64a4>] __btrfs_run_delayed_refs+0x394/0x11d0 [btrfs] [1212302.630008] [<ffffffffa04db379>] btrfs_run_delayed_refs.part.66+0x69/0x280 [btrfs] [1212302.630008] [<ffffffffa04ed2ad>] __btrfs_end_transaction+0x2ad/0x3d0 [btrfs] [1212302.630008] [<ffffffffa04f7505>] btrfs_evict_inode+0x4a5/0x500 [btrfs] [1212302.630008] [<ffffffff811b9e28>] evict+0xa8/0x190 [1212302.630008] [<ffffffff811b0330>] do_unlinkat+0x1a0/0x2b0 I was also able to reproduce this on a 3.19 kernel, corresponding to Chris' integration branch from about a month ago, running the following stress test on a qemu/kvm guest (with 4 virtual cpus and 16Gb of ram): while true; do mkfs.btrfs -l 4096 -f -b `expr 20 \* 1024 \* 1024 \* 1024` /dev/sdd mount /dev/sdd /mnt snapshot_cmd="btrfs subvolume snapshot -r /mnt" snapshot_cmd="$snapshot_cmd /mnt/snap_\`date +'%H_%M_%S_%N'\`" fsstress -d /mnt -n 25000 -p 8 -x "$snapshot_cmd" -X 100 umount /mnt done Which usually triggers the BUG_ON within less than 24 hours: [49558.618097] ------------[ cut here ]------------ [49558.619732] kernel BUG at fs/btrfs/extent_io.c:4551! (...) [49558.620031] CPU: 3 PID: 23908 Comm: fsstress Tainted: G W 3.19.0-btrfs-next-7+ #3 [49558.620031] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [49558.620031] task: ffff8800319fc0d0 ti: ffff880220da8000 task.ti: ffff880220da8000 [49558.620031] RIP: 0010:[<ffffffffa0476b1a>] [<ffffffffa0476b1a>] btrfs_release_extent_buffer_page+0x20/0xe9 [btrfs] (...) [49558.620031] Call Trace: [49558.620031] [<ffffffffa0476c73>] release_extent_buffer+0x90/0xd3 [btrfs] [49558.620031] [<ffffffff8142b10c>] ? _raw_spin_lock+0x3b/0x43 [49558.620031] [<ffffffffa0477052>] ? free_extent_buffer+0x37/0x94 [btrfs] [49558.620031] [<ffffffffa04770ab>] free_extent_buffer+0x90/0x94 [btrfs] [49558.620031] [<ffffffffa04396d5>] btrfs_release_path+0x4a/0x69 [btrfs] [49558.620031] [<ffffffffa0444907>] __btrfs_free_extent+0x778/0x80c [btrfs] [49558.620031] [<ffffffffa044a485>] __btrfs_run_delayed_refs+0xad2/0xc62 [btrfs] [49558.728054] [<ffffffff811420d5>] ? kmemleak_alloc_recursive.constprop.52+0x16/0x18 [49558.728054] [<ffffffffa044c1e8>] btrfs_run_delayed_refs+0x6d/0x1ba [btrfs] [49558.728054] [<ffffffffa045917f>] ? join_transaction.isra.9+0xb9/0x36b [btrfs] [49558.728054] [<ffffffffa045a75c>] btrfs_commit_transaction+0x4c/0x981 [btrfs] [49558.728054] [<ffffffffa0434f86>] btrfs_sync_fs+0xd5/0x10d [btrfs] [49558.728054] [<ffffffff81155923>] ? iterate_supers+0x60/0xc4 [49558.728054] [<ffffffff8117966a>] ? do_sync_work+0x91/0x91 [49558.728054] [<ffffffff8117968a>] sync_fs_one_sb+0x20/0x22 [49558.728054] [<ffffffff81155939>] iterate_supers+0x76/0xc4 [49558.728054] [<ffffffff811798e8>] sys_sync+0x55/0x83 [49558.728054] [<ffffffff8142bbd2>] system_call_fastpath+0x12/0x17 Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2015-05-11Btrfs: fix race between block group creation and their cache writeoutFilipe Manana
So creating a block group has 2 distinct phases: Phase 1 - creates the btrfs_block_group_cache item and adds it to the rbtree fs_info->block_group_cache_tree and to the corresponding list space_info->block_groups[]; Phase 2 - adds the block group item to the extent tree and corresponding items to the chunk tree. The first phase adds the block_group_cache_item to a list of pending block groups in the transaction handle, and phase 2 happens when btrfs_end_transaction() is called against the transaction handle. It happens that once phase 1 completes, other concurrent tasks that use their own transaction handle, but points to the same running transaction (struct btrfs_trans_handle->transaction), can use this block group for space allocations and therefore mark it dirty. Dirty block groups are tracked in a list belonging to the currently running transaction (struct btrfs_transaction) and not in the transaction handle (btrfs_trans_handle). This is a problem because once a task calls btrfs_commit_transaction(), it calls btrfs_start_dirty_block_groups() which will see all dirty block groups and attempt to start their writeout, including those that are still attached to the transaction handle of some concurrent task that hasn't called btrfs_end_transaction() yet - which means those block groups haven't gone through phase 2 yet and therefore when write_one_cache_group() is called, it won't find the block group items in the extent tree and abort the current transaction with -ENOENT, turning the fs into readonly mode and require a remount. Fix this by ignoring -ENOENT when looking for block group items in the extent tree when we attempt to start the writeout of the block group caches outside the critical section of the transaction commit. We will try again later during the critical section and if there we still don't find the block group item in the extent tree, we then abort the current transaction. This issue happened twice, once while running fstests btrfs/067 and once for btrfs/078, which produced the following trace: [ 3278.703014] WARNING: CPU: 7 PID: 18499 at fs/btrfs/super.c:260 __btrfs_abort_transaction+0x52/0x114 [btrfs]() [ 3278.707329] BTRFS: Transaction aborted (error -2) (...) [ 3278.731555] Call Trace: [ 3278.732396] [<ffffffff8142fa46>] dump_stack+0x4f/0x7b [ 3278.733860] [<ffffffff8108b6a2>] ? console_unlock+0x361/0x3ad [ 3278.735312] [<ffffffff81045ea5>] warn_slowpath_common+0xa1/0xbb [ 3278.736874] [<ffffffffa03ada6d>] ? __btrfs_abort_transaction+0x52/0x114 [btrfs] [ 3278.738302] [<ffffffff81045f05>] warn_slowpath_fmt+0x46/0x48 [ 3278.739520] [<ffffffffa03ada6d>] __btrfs_abort_transaction+0x52/0x114 [btrfs] [ 3278.741222] [<ffffffffa03b9e56>] write_one_cache_group+0xae/0xbf [btrfs] [ 3278.742797] [<ffffffffa03c487b>] btrfs_start_dirty_block_groups+0x170/0x2b2 [btrfs] [ 3278.744492] [<ffffffffa03d309c>] btrfs_commit_transaction+0x130/0x9c9 [btrfs] [ 3278.746084] [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf [ 3278.747249] [<ffffffffa03e5660>] btrfs_sync_file+0x313/0x387 [btrfs] [ 3278.748744] [<ffffffff8117acad>] vfs_fsync_range+0x95/0xa4 [ 3278.749958] [<ffffffff81435b54>] ? ret_from_sys_call+0x1d/0x58 [ 3278.751218] [<ffffffff8117acd8>] vfs_fsync+0x1c/0x1e [ 3278.754197] [<ffffffff8117ae54>] do_fsync+0x34/0x4e [ 3278.755192] [<ffffffff8117b07c>] SyS_fsync+0x10/0x14 [ 3278.756236] [<ffffffff81435b32>] system_call_fastpath+0x12/0x17 [ 3278.757366] ---[ end trace 9a4d4df4969709aa ]--- Fixes: 1bbc621ef284 ("Btrfs: allow block group cache writeout outside critical section in commit") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-05-11Btrfs: fix panic when starting bg cache writeout after IO errorFilipe Manana
When waiting for the writeback of block group cache we returned immediately if there was an error during writeback without waiting for the ordered extent to complete. This left a short time window where if some other task attempts to start the writeout for the same block group cache it can attempt to add a new ordered extent, starting at the same offset (0) before the previous one is removed from the ordered tree, causing an ordered tree panic (calls BUG()). This normally doesn't happen in other write paths, such as buffered writes or direct IO writes for regular files, since before marking page ranges dirty we lock the ranges and wait for any ordered extents within the range to complete first. Fix this by making btrfs_wait_ordered_range() not return immediately if it gets an error from the writeback, waiting for all ordered extents to complete first. This issue happened often when running the fstest btrfs/088 and it's easy to trigger it by running in a loop until the panic happens: for ((i = 1; i <= 10000; i++)) do ./check btrfs/088 ; done [17156.862573] BTRFS critical (device sdc): panic in ordered_data_tree_panic:70: Inconsistency in ordered tree at offset 0 (errno=-17 Object already exists) [17156.864052] ------------[ cut here ]------------ [17156.864052] kernel BUG at fs/btrfs/ordered-data.c:70! (...) [17156.864052] Call Trace: [17156.864052] [<ffffffffa03876e3>] btrfs_add_ordered_extent+0x12/0x14 [btrfs] [17156.864052] [<ffffffffa03787e2>] run_delalloc_nocow+0x5bf/0x747 [btrfs] [17156.864052] [<ffffffffa03789ff>] run_delalloc_range+0x95/0x353 [btrfs] [17156.864052] [<ffffffffa038b7fe>] writepage_delalloc.isra.16+0xb9/0x13f [btrfs] [17156.864052] [<ffffffffa038d75b>] __extent_writepage+0x129/0x1f7 [btrfs] [17156.864052] [<ffffffffa038da5a>] extent_write_cache_pages.isra.15.constprop.28+0x231/0x2f4 [btrfs] [17156.864052] [<ffffffff810ad2af>] ? __module_text_address+0x12/0x59 [17156.864052] [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf [17156.864052] [<ffffffffa038df76>] extent_writepages+0x4b/0x5c [btrfs] [17156.864052] [<ffffffff81144431>] ? kmem_cache_free+0x9b/0xce [17156.864052] [<ffffffffa0376a46>] ? btrfs_submit_direct+0x3fc/0x3fc [btrfs] [17156.864052] [<ffffffffa0389cd6>] ? free_extent_state+0x8c/0xc1 [btrfs] [17156.864052] [<ffffffffa0374871>] btrfs_writepages+0x28/0x2a [btrfs] [17156.864052] [<ffffffff8110c4c8>] do_writepages+0x23/0x2c [17156.864052] [<ffffffff81102f36>] __filemap_fdatawrite_range+0x5a/0x61 [17156.864052] [<ffffffff81102f6e>] filemap_fdatawrite_range+0x13/0x15 [17156.864052] [<ffffffffa0383ef7>] btrfs_fdatawrite_range+0x21/0x48 [btrfs] [17156.864052] [<ffffffffa03ab89e>] __btrfs_write_out_cache.isra.14+0x2d9/0x3a7 [btrfs] [17156.864052] [<ffffffffa03ac1ab>] ? btrfs_write_out_cache+0x41/0xdc [btrfs] [17156.864052] [<ffffffffa03ac1fd>] btrfs_write_out_cache+0x93/0xdc [btrfs] [17156.864052] [<ffffffffa0363847>] ? btrfs_start_dirty_block_groups+0x13a/0x2b2 [btrfs] [17156.864052] [<ffffffffa03638e6>] btrfs_start_dirty_block_groups+0x1d9/0x2b2 [btrfs] [17156.864052] [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf [17156.864052] [<ffffffffa037209e>] btrfs_commit_transaction+0x130/0x9c9 [btrfs] [17156.864052] [<ffffffffa034c748>] btrfs_sync_fs+0xe1/0x12d [btrfs] Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-05-11Btrfs: fix crash after inode cache writeback failureFilipe Manana
If the writeback of an inode cache failed we were unnecessarilly attempting to release again the delalloc metadata that we previously reserved. However attempting to do this a second time triggers an assertion at drop_outstanding_extent() because we have no more outstanding extents for our inode cache's inode. If we were able to start writeback of the cache the reserved metadata space is released at btrfs_finished_ordered_io(), even if an error happens during writeback. So make sure we don't repeat the metadata space release if writeback started for our inode cache. This issue was trivial to reproduce by running the fstest btrfs/088 with "-o inode_cache", which triggered the assertion leading to a BUG() call and requiring a reboot in order to run the remaining fstests. Trace produced by btrfs/088: [255289.385904] BTRFS: assertion failed: BTRFS_I(inode)->outstanding_extents >= num_extents, file: fs/btrfs/extent-tree.c, line: 5276 [255289.388094] ------------[ cut here ]------------ [255289.389184] kernel BUG at fs/btrfs/ctree.h:4057! [255289.390125] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC (...) [255289.392068] Call Trace: [255289.392068] [<ffffffffa035e774>] drop_outstanding_extent+0x3d/0x6d [btrfs] [255289.392068] [<ffffffffa0364988>] btrfs_delalloc_release_metadata+0x54/0xe3 [btrfs] [255289.392068] [<ffffffffa03b4174>] btrfs_write_out_ino_cache+0x95/0xad [btrfs] [255289.392068] [<ffffffffa036f5c4>] btrfs_save_ino_cache+0x275/0x2dc [btrfs] [255289.392068] [<ffffffffa03e2d83>] commit_fs_roots.isra.12+0xaa/0x137 [btrfs] [255289.392068] [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf [255289.392068] [<ffffffffa037841f>] ? btrfs_commit_transaction+0x4b1/0x9c9 [btrfs] [255289.392068] [<ffffffff814351a4>] ? _raw_spin_unlock+0x32/0x46 [255289.392068] [<ffffffffa037842e>] btrfs_commit_transaction+0x4c0/0x9c9 [btrfs] (...) Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-05-11phy: core: Fix error checking in (devm_)phy_optional_getAxel Lin
Don't pass valid pointer to PTR_ERR, use PTR_ERR(phy) only when IS_ERR(phy) is true. Signed-off-by: Axel Lin <axel.lin@ingics.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2015-05-11Merge branch 'x86/asm' into x86/apic, to resolve a conflictIngo Molnar
Conflicts: arch/x86/kernel/apic/io_apic.c arch/x86/kernel/apic/vector.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11iommu/vt-d: Fix passthrough mode with translation-disabled devicesDavid Woodhouse
When we use 'intel_iommu=igfx_off' to disable translation for the graphics, and when we discover that the BIOS has misconfigured the DMAR setup for I/OAT, we use a special DUMMY_DEVICE_DOMAIN_INFO value in dev->archdata.iommu to indicate that translation is disabled. With passthrough mode, we were attempting to dereference that as a normal pointer to a struct device_domain_info when setting up an identity mapping for the affected device. This fixes the problem by making device_to_iommu() explicitly check for the special value and indicate that no IOMMU was found to handle the devices in question. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Cc: stable@vger.kernel.org (which means you can pick up 18436afdc now too)
2015-05-11drm/i915: Avoid GPU hang when coming out of s3 or s4Peter Antoine
This patch fixes a timing issue that causes a GPU hang when the system comes out of power saving. During pm_resume, We are submitting batchbuffers before enabling Interrupts this is causing us to miss the context switch interrupt, and in consequence intel_execlists_handle_ctx_events is not triggered. This patch is based on a patch from Deepak S <deepak.s@intel.com> from another platform. The patch fixes an issue introduced by: commit e7778be1eab918274f79603d7c17b3ec8be77386 drm/i915: Fix startup failure in LRC mode after recent init changes The above patch added a call to init_context() to fix an issue introduced by a previous patch. But, it then opened up a small timing window for the batches being added by the init_context (basically setting up the context) to complete before the interrupts have been turned on, thus hanging the GPU. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89600 Cc: stable@vger.kernel.org # 4.0+ Signed-off-by: Peter Antoine <peter.antoine@intel.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> [Jani: fixed typo in subject, massaged the comments a bit] Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2015-05-11ARM: dove: Add clock-names to CuBox Si5351 clk generatorSebastian Hesselbarth
Si5351 clock generator on CuBox uses XTAL as clock reference, name the clock phandle accordingly. Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
2015-05-11mac80211: move WEP tailroom size checkJanusz Dziedzic
Remove checking tailroom when adding IV as it uses only headroom, and move the check to the ICV generation that actually needs the tailroom. In other case I hit such warning and datapath don't work, when testing: - IBSS + WEP - ath9k with hw crypt enabled - IPv6 data (ping6) WARNING: CPU: 3 PID: 13301 at net/mac80211/wep.c:102 ieee80211_wep_add_iv+0x129/0x190 [mac80211]() [...] Call Trace: [<ffffffff817bf491>] dump_stack+0x45/0x57 [<ffffffff8107746a>] warn_slowpath_common+0x8a/0xc0 [<ffffffff8107755a>] warn_slowpath_null+0x1a/0x20 [<ffffffffc09ae109>] ieee80211_wep_add_iv+0x129/0x190 [mac80211] [<ffffffffc09ae7ab>] ieee80211_crypto_wep_encrypt+0x6b/0xd0 [mac80211] [<ffffffffc09d3fb1>] invoke_tx_handlers+0xc51/0xf30 [mac80211] [...] Cc: stable@vger.kernel.org Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-05-11ALSA: hda - Add headset mic quirk for Dell Inspiron 5548David Henningsson
This enables the headset microphone on Dell Inspiron 5548, or at least some variants of it. Cc: stable@vger.kernel.org BugLink: https://bugs.launchpad.net/bugs/1452175 Signed-off-by: David Henningsson <david.henningsson@canonical.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-05-11namei: store seq numbers in nd->stack[]Al Viro
we'll need them for unlazy_walk() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11new helper: __legitimize_mnt()Al Viro
same as legitimize_mnt(), except that it does *not* drop and regain rcu_read_lock; return values are 0 => grabbed a reference, we are fine 1 => failed, just go away -1 => failed, go away and mntput(bastard) when outside of rcu_read_lock Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11namei: make may_follow_link() safe in RCU modeAl Viro
We *can't* call that audit garbage in RCU mode - it's doing a weird mix of allocations (GFP_NOFS, immediately followed by GFP_KERNEL) and I'm not touching that... thing again. So if this security sclero^Whardening feature gets triggered when we are in RCU mode, tough - we'll fail with -ECHILD and have everything restarted in non-RCU mode. Only to hit the same test and fail, this time with EACCES and with (oh, rapture) an audit spew produced. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11namei: make put_link() RCU-safeAl Viro
very simple - just make path_put() conditional on !RCU. Note that right now it doesn't get called in RCU mode - we leave it before getting anything into stack. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11new helper: free_page_put_link()Al Viro
similar to kfree_put_link() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11switch ->put_link() from dentry to inodeAl Viro
only one instance looks at that argument at all; that sole exception wants inode rather than dentry. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11security: make inode_follow_link RCU-walk awareNeilBrown
inode_follow_link now takes an inode and rcu flag as well as the dentry. inode is used in preference to d_backing_inode(dentry), particularly in RCU-walk mode. selinux_inode_follow_link() gets dentry_has_perm() and inode_has_perm() open-coded into it so that it can call avc_has_perm_flags() in way that is safe if LOOKUP_RCU is set. Calling avc_has_perm_flags() with rcu_read_lock() held means that when avc_has_perm_noaudit calls avc_compute_av(), the attempt to rcu_read_unlock() before calling security_compute_av() will not actually drop the RCU read-lock. However as security_compute_av() is completely in a read_lock()ed region, it should be safe with the RCU read-lock held. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11security/selinux: pass 'flags' arg to avc_audit() and avc_has_perm_flags()NeilBrown
This allows MAY_NOT_BLOCK to be passed, in RCU-walk mode, through the new avc_has_perm_flags() to avc_audit() and thence the slow_avc_audit. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11namei: pick_link() callers already have inodeAl Viro
no need to refetch (and once we move unlazy out of there, recheck ->d_seq). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11VFS: Handle lower layer dentry/inode in pathwalkDavid Howells
Make use of d_backing_inode() in pathwalk to gain access to an inode or dentry that's on a lower layer. Signed-off-by: David Howells <dhowells@redhat.com>
2015-05-11namei: store inode in nd->stack[]Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11namei: don't mangle nd->seq in lookup_fast()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11namei: explicitly pass seq number to unlazy_walk() when dentry != NULLAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11link_path_walk: use explicit returns for failure exitsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11namei: lift terminate_walk() all the way upAl Viro
Lift it from link_path_walk(), trailing_symlink(), lookup_last(), mountpoint_last(), complete_walk() and do_last(). A _lot_ of those suckers merge. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11namei: lift link_path_walk() call out of trailing_symlink()Al Viro
Make trailing_symlink() return the pathname to traverse or ERR_PTR(-E...). A subtle point is that for "magic" symlinks it returns "" now - that leads to link_path_walk("", nd), which is immediately returning 0 and we are back to the treatment of the last component, at whereever the damn thing has left us. Reduces the stack footprint - link_path_walk() called on more shallow stack now. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11namei: path_init() calling conventions changeAl Viro
* lift link_path_walk() into callers; moving it down into path_init() had been a mistake. Stack footprint, among other things... * do _not_ call path_cleanup() after path_init() failure; on all failure exits out of it we have nothing for path_cleanup() to do * have path_init() return pathname or ERR_PTR(-E...) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11namei: get rid of nameidata->baseAl Viro
we can do fdput() under rcu_read_lock() just fine; all we need to take care of is fetching nd->inode value first. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11perf/x86/intel/uncore: Add Broadwell-U uncore IMC PMU supportStephane Eranian
This patch enables the uncore Memory Controller (IMC) PMU support for Intel Broadwell-U (Model 61) mobile processors. The IMC PMU enables measuring memory bandwidth. To use with perf: $ perf stat -a -I 1000 -e uncore_imc/data_reads/,uncore_imc/data_writes/ sleep 10 Tested-by: Sonny Rao <sonnyrao@chromium.org> Signed-off-by: Stephane Eranian <eranian@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kan.liang@intel.com Cc: peterz@infradead.org Link: http://lkml.kernel.org/r/20150423065642.GA4890@thinkpad Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11Merge branch 'perf/urgent' into perf/core, to resolve conflictsIngo Molnar
Conflicts: tools/perf/builtin-kmem.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11x86/mm/pageattr: Remove an unused variable in slow_virt_to_phys()Dexuan Cui
The patch doesn't change any logic. Signed-off-by: Dexuan Cui <decui@microsoft.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1429776428-4475-1-git-send-email-decui@microsoft.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11perf/x86/rapl: Enable Broadwell-U RAPL supportStephane Eranian
This patch enables RAPL counters (energy consumption counters) support for Intel Broadwell-U processors (Model 61): To use: $ perf stat -a -I 1000 -e power/energy-cores/,power/energy-pkg/,power/energy-ram/ sleep 10 Signed-off-by: Stephane Eranian <eranian@google.com> Cc: <stable@vger.kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: jacob.jun.pan@linux.intel.com Cc: kan.liang@intel.com Cc: peterz@infradead.org Cc: sonnyrao@chromium.org Link: http://lkml.kernel.org/r/20150423070709.GA4970@thinkpad Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11x86/mm: Add ioremap_uc() helper to map memory uncacheable (not UC-)Luis R. Rodriguez
ioremap_nocache() currently uses UC- by default. Our goal is to eventually make UC the default. Linux maps UC- to PCD=1, PWT=0 page attributes on non-PAT systems. Linux maps UC to PCD=1, PWT=1 page attributes on non-PAT systems. On non-PAT and PAT systems a WC MTRR has different effects on pages with either of these attributes. In order to help with a smooth transition its best to enable use of UC (PCD,1, PWT=1) on a region as that ensures a WC MTRR will have no effect on a region, this however requires us to have an way to declare a region as UC and we currently do not have a way to do this. WC MTRR on non-PAT system with PCD=1, PWT=0 (UC-) yields WC. WC MTRR on non-PAT system with PCD=1, PWT=1 (UC) yields UC. WC MTRR on PAT system with PCD=1, PWT=0 (UC-) yields WC. WC MTRR on PAT system with PCD=1, PWT=1 (UC) yields UC. A flip of the default ioremap_nocache() behaviour from UC- to UC can therefore regress a memory region from effective memory type WC to UC if MTRRs are used. Use of MTRRs should be phased out and in the best case only arch_phys_wc_add() use will remain, even if this happens arch_phys_wc_add() will have an effect on non-PAT systems and changes to default ioremap_nocache() behaviour could regress drivers. Now, ideally we'd use ioremap_nocache() on the regions in which we'd need uncachable memory types and avoid any MTRRs on those regions. There are however some restrictions on MTRRs use, such as the requirement of having the base and size of variable sized MTRRs to be powers of two, which could mean having to use a WC MTRR over a large area which includes a region in which write-combining effects are undesirable. Add ioremap_uc() to help with the both phasing out of MTRR use and also provide a way to blacklist small WC undesirable regions in devices with mixed regions which are size-implicated to use large WC MTRRs. Use of ioremap_uc() helps phase out MTRR use by avoiding regressions with an eventual flip of default behaviour or ioremap_nocache() from UC- to UC. Drivers working with WC MTRRs can use the below table to review and consider the use of ioremap*() and similar helpers to ensure appropriate behaviour long term even if default ioremap_nocache() behaviour changes from UC- to UC. Although ioremap_uc() is being added we leave set_memory_uc() to use UC- as only initial memory type setup is required to be able to accommodate existing device drivers and phase out MTRR use. It should also be clarified that set_memory_uc() cannot be used with IO memory, even though its use will not return any errors, it really has no effect. ---------------------------------------------------------------------- MTRR Non-PAT PAT Linux ioremap value Effective memory type ---------------------------------------------------------------------- Non-PAT | PAT PAT |PCD ||PWT ||| WC 000 WB _PAGE_CACHE_MODE_WB WC | WC WC 001 WC _PAGE_CACHE_MODE_WC WC* | WC WC 010 UC- _PAGE_CACHE_MODE_UC_MINUS WC* | WC WC 011 UC _PAGE_CACHE_MODE_UC UC | UC ---------------------------------------------------------------------- Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Antonino Daplas <adaplas@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dave Airlie <airlied@redhat.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Travis <travis@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Suresh Siddha <sbsiddha@gmail.com> Cc: Thierry Reding <treding@nvidia.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Ville Syrjälä <syrjala@sci.fi> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-fbdev@vger.kernel.org Link: http://lkml.kernel.org/r/1430343851-967-2-git-send-email-mcgrof@do-not-panic.com Link: http://lkml.kernel.org/r/1431332153-18566-9-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11x86/mm/mtrr: Remove incorrect address check in __mtrr_type_lookup()Toshi Kani
__mtrr_type_lookup() checks MTRR fixed ranges when mtrr_state.have_fixed is set and start is less than 0x100000. However, the 'else if (start < 0x1000000)' in the code checks with an incorrect address as it has an extra-zero in the address. The code still runs correctly as this check is meaningless, though. This patch replaces the incorrect address check with 'else' with no condition. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Elliott@hp.com Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dave.hansen@intel.com Cc: linux-mm <linux-mm@kvack.org> Cc: pebolle@tiscali.nl Link: http://lkml.kernel.org/r/1427234921-19737-4-git-send-email-toshi.kani@hp.com Link: http://lkml.kernel.org/r/1431332153-18566-8-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11x86/mm: Add kerneldoc comments for pcommit_sfence()Ross Zwisler
Add kerneldoc comments for pcommit_sfence() describing the purpose of the PCOMMIT instruction and demonstrating its usage with an example. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H Peter Anvin <h.peter.anvin@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Link: http://lkml.kernel.org/r/1430261196-2401-1-git-send-email-ross.zwisler@linux.intel.com Link: http://lkml.kernel.org/r/1431332153-18566-7-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11x86/mm: Do not flush last cacheline twice in clflush_cache_range()Ross Zwisler
The current algorithm used in clflush_cache_range() can cause the last cache line of the buffer to be flushed twice. Fix that algorithm so that each cache line will only be flushed once. Reported-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Link: http://lkml.kernel.org/r/1430259192-18802-1-git-send-email-ross.zwisler@linux.intel.com Link: http://lkml.kernel.org/r/1431332153-18566-5-git-send-email-bp@alien8.de [ Changed it to 'void *' to simplify the type conversions. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11x86/cpu/microcode: Zap changelogBorislav Petkov
It is useless at best and git history has it all detailed anyway. Update copyright while at it. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431332153-18566-3-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11x86/alternatives: Switch AMD F15h and later to the P6 NOPsBorislav Petkov
Software optimization guides for both F15h and F16h cite those NOPs as the optimal ones. A microbenchmark confirms that actually even older families are better with the single-insn NOPs so switch to them for the alternatives. Cycles count below includes the loop overhead of the measurement but that overhead is the same with all runs. F10h, revE: ----------- Running NOP tests, 1000 NOPs x 1000000 repetitions K8: 90 288.212282 cycles 66 90 288.220840 cycles 66 66 90 288.219447 cycles 66 66 66 90 288.223204 cycles 66 66 90 66 90 571.393424 cycles 66 66 90 66 66 90 571.374919 cycles 66 66 66 90 66 66 90 572.249281 cycles 66 66 66 90 66 66 66 90 571.388651 cycles P6: 90 288.214193 cycles 66 90 288.225550 cycles 0f 1f 00 288.224441 cycles 0f 1f 40 00 288.225030 cycles 0f 1f 44 00 00 288.233558 cycles 66 0f 1f 44 00 00 324.792342 cycles 0f 1f 80 00 00 00 00 325.657462 cycles 0f 1f 84 00 00 00 00 00 430.246643 cycles F14h: ---- Running NOP tests, 1000 NOPs x 1000000 repetitions K8: 90 510.404890 cycles 66 90 510.432117 cycles 66 66 90 510.561858 cycles 66 66 66 90 510.541865 cycles 66 66 90 66 90 1014.192782 cycles 66 66 90 66 66 90 1014.226546 cycles 66 66 66 90 66 66 90 1014.334299 cycles 66 66 66 90 66 66 66 90 1014.381205 cycles P6: 90 510.436710 cycles 66 90 510.448229 cycles 0f 1f 00 510.545100 cycles 0f 1f 40 00 510.502792 cycles 0f 1f 44 00 00 510.589517 cycles 66 0f 1f 44 00 00 510.611462 cycles 0f 1f 80 00 00 00 00 511.166794 cycles 0f 1f 84 00 00 00 00 00 511.651641 cycles F15h: ----- Running NOP tests, 1000 NOPs x 1000000 repetitions K8: 90 243.128396 cycles 66 90 243.129883 cycles 66 66 90 243.131631 cycles 66 66 66 90 242.499324 cycles 66 66 90 66 90 481.829083 cycles 66 66 90 66 66 90 481.884413 cycles 66 66 66 90 66 66 90 481.851446 cycles 66 66 66 90 66 66 66 90 481.409220 cycles P6: 90 243.127026 cycles 66 90 243.130711 cycles 0f 1f 00 243.122747 cycles 0f 1f 40 00 242.497617 cycles 0f 1f 44 00 00 245.354461 cycles 66 0f 1f 44 00 00 361.930417 cycles 0f 1f 80 00 00 00 00 362.844944 cycles 0f 1f 84 00 00 00 00 00 480.514948 cycles F16h: ----- Running NOP tests, 1000 NOPs x 1000000 repetitions K8: 90 507.793298 cycles 66 90 507.789636 cycles 66 66 90 507.826490 cycles 66 66 66 90 507.859075 cycles 66 66 90 66 90 1008.663129 cycles 66 66 90 66 66 90 1008.696259 cycles 66 66 66 90 66 66 90 1008.692517 cycles 66 66 66 90 66 66 66 90 1008.755399 cycles P6: 90 507.795232 cycles 66 90 507.794761 cycles 0f 1f 00 507.834901 cycles 0f 1f 40 00 507.822629 cycles 0f 1f 44 00 00 507.838493 cycles 66 0f 1f 44 00 00 507.908597 cycles 0f 1f 80 00 00 00 00 507.946417 cycles 0f 1f 84 00 00 00 00 00 507.954960 cycles Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431332153-18566-2-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11x86/vdso: Fix 'make bzImage' on older distrosOleg Nesterov
Change HOST_EXTRACFLAGS to include arch/x86/include/uapi along with include/uapi. This looks more consistent, and this fixes "make bzImage" on my old distro which doesn't have asm/bitsperlong.h in /usr/include/. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: <stable@vger.kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 6f121e548f83 ("x86, vdso: Reimplement vdso.so preparation in build-time C") Link: http://lkml.kernel.org/r/1431332153-18566-6-git-send-email-bp@alien8.de Link: http://lkml.kernel.org/r/20150507165835.GB18652@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11Merge tag 'ras_for_4.2' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras into x86/ras Pull RAS updates from Borislav Petkov: - RAS: Add support for deferred errors on AMD (Aravind Gopalakrishnan) This is an important RAS feature which adds hardware support for poisoned data. That means roughly that the hardware marks data which it has detected as corrupted but wasn't able to correct, as poisoned data and raises an APIC interrupt to signal that in the form of a deferred error. It is the OS's responsibility then to take proper recovery action and thus prolonge system lifetime as far as possible. - Misc cleanups ontop. (Borislav Petkov)" Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11locking/pvqspinlock: Rename QUEUED_SPINLOCK to QUEUED_SPINLOCKSIngo Molnar
Valentin Rothberg reported that we use CONFIG_QUEUED_SPINLOCKS in arch/x86/kernel/paravirt_patch_32.c, while the symbol is called CONFIG_QUEUED_SPINLOCK. (Note the extra 'S') But the typo was natural: the proper English term for such a generic object would be 'queued spinlocks' - so rename this and related symbols accordingly to the plural form. Reported-by: Valentin Rothberg <valentinrothberg@gmail.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <Waiman.Long@hp.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11locking/pvqspinlock: Replace xchg() by the more descriptive set_mb()Waiman Long
The xchg() function was used in pv_wait_node() to set a certain value and provide a memory barrier which is what the set_mb() function is for. This patch replaces the xchg() call by set_mb(). Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Waiman Long <Waiman.Long@hp.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11ARC: inline cache flush toggle helpersVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-05-11ARC: With earlycon in use, retire EARLY_PRINTKVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-05-11x86/asm/entry: Fix remaining use of SYSCALL_VECTORIngo Molnar
Commit: 51bb92843edc ("x86/asm/entry: Remove SYSCALL_VECTOR") Converted most uses of SYSCALL_VECTOR to IA32_SYSCALL_VECTOR, but forgot about lguest. Cc: Brian Gerst <brgerst@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431185813-15413-4-git-send-email-brgerst@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-10namei: split off filename_lookupat() with LOOKUP_PARENTAl Viro
new functions: filename_parentat() and path_parentat() resp. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10namei: may_follow_link() - lift terminate_walk() on failures into callerAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10namei: take increment of nd->depth into pick_link()Al Viro
Makes the situation much more regular - we avoid a strange state when the element just after the top of stack is used to store struct path of symlink, but isn't counted in nd->depth. This is much more regular, so the normal failure exits, etc., work fine. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10namei: kill nd->linkAl Viro
Just store it in nd->stack[nd->depth].link right in pick_link(). Now that we make sure of stack expansion in pick_link(), we can do so... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>