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* xen, mm: Set IORESOURCE_SYSTEM_RAM to System RAMToshi Kani2016-01-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Set IORESOURCE_SYSTEM_RAM in struct resource.flags of "System RAM" entries. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: David Vrabel <david.vrabel@citrix.com> # xen Cc: Andrew Banman <abanman@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: linux-arch@vger.kernel.org Cc: linux-mm <linux-mm@kvack.org> Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1453841853-11383-9-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'stable/for-linus-4.5' of ↵Linus Torvalds2016-01-291-2/+2
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm Pull cleancache cleanups from Konrad Rzeszutek Wilk: "Simple cleanups" * 'stable/for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm: include/linux/cleancache.h: Clean up code cleancache: constify cleancache_ops structure
| * cleancache: constify cleancache_ops structureJulia Lawall2016-01-271-2/+2
| | | | | | | | | | | | | | | | | | The cleancache_ops structure is never modified, so declare it as const. Done with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | vmstat: Remove BUG_ON from vmstat_updateChristoph Lameter2016-01-241-11/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we detect that there is nothing to do just set the flag and do not check if it was already set before. Races really do not matter. If the flag is set by any code then the shepherd will start dealing with the situation and reenable the vmstat workers when necessary again. Since commit 0eb77e988032 ("vmstat: make vmstat_updater deferrable again and shut down on idle") quiet_vmstat might update cpu_stat_off and mark a particular cpu to be handled by vmstat_shepherd. This might trigger a VM_BUG_ON in vmstat_update because the work item might have been sleeping during the idle period and see the cpu_stat_off updated after the wake up. The VM_BUG_ON is therefore misleading and no more appropriate. Moreover it doesn't really suite any protection from real bugs because vmstat_shepherd will simply reschedule the vmstat_work anytime it sees a particular cpu set or vmstat_update would do the same from the worker context directly. Even when the two would race the result wouldn't be incorrect as the counters update is fully idempotent. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-linus' of ↵Linus Torvalds2016-01-233-19/+18
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull final vfs updates from Al Viro: - The ->i_mutex wrappers (with small prereq in lustre) - a fix for too early freeing of symlink bodies on shmem (they need to be RCU-delayed) (-stable fodder) - followup to dedupe stuff merged this cycle * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: abort dedupe loop if fatal signals are pending make sure that freeing shmem fast symlinks is RCU-delayed wrappers for ->i_mutex access lustre: remove unused declaration
| * | make sure that freeing shmem fast symlinks is RCU-delayedAl Viro2016-01-221-5/+4
| | | | | | | | | | | | | | | Cc: stable@vger.kernel.org # v4.2+ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | wrappers for ->i_mutex accessAl Viro2016-01-223-14/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | tree wide: use kvfree() than conditional kfree()/vfree()Tetsuo Handa2016-01-221-11/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are many locations that do if (memory_was_allocated_by_vmalloc) vfree(ptr); else kfree(ptr); but kvfree() can handle both kmalloc()ed memory and vmalloc()ed memory using is_vmalloc_addr(). Unless callers have special reasons, we can replace this branch with kvfree(). Please check and reply if you found problems. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Jan Kara <jack@suse.com> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Reviewed-by: Andreas Dilger <andreas.dilger@intel.com> Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net> Acked-by: David Rientjes <rientjes@google.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: Boris Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | dax: add support for fsync/syncRoss Zwisler2016-01-221-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To properly handle fsync/msync in an efficient way DAX needs to track dirty pages so it is able to flush them durably to media on demand. The tracking of dirty pages is done via the radix tree in struct address_space. This radix tree is already used by the page writeback infrastructure for tracking dirty pages associated with an open file, and it already has support for exceptional (non struct page*) entries. We build upon these features to add exceptional entries to the radix tree for DAX dirty PMD or PTE pages at fault time. [dan.j.williams@intel.com: fix dax_pmd_dbg build warning] Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Dave Chinner <david@fromorbit.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.com> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm: add find_get_entries_tag()Ross Zwisler2016-01-221-0/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add find_get_entries_tag() to the family of functions that include find_get_entries(), find_get_pages() and find_get_pages_tag(). This is needed for DAX dirty page handling because we need a list of both page offsets and radix tree entries ('indices' and 'entries' in this function) that are marked with the PAGECACHE_TAG_TOWRITE tag. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Dave Chinner <david@fromorbit.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | dax: support dirty DAX entries in radix treeRoss Zwisler2016-01-224-39/+60
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for tracking dirty DAX entries in the struct address_space radix tree. This tree is already used for dirty page writeback, and it already supports the use of exceptional (non struct page*) entries. In order to properly track dirty DAX pages we will insert new exceptional entries into the radix tree that represent dirty DAX PTE or PMD pages. These exceptional entries will also contain the writeback addresses for the PTE or PMD faults that we can use at fsync/msync time. There are currently two types of exceptional entries (shmem and shadow) that can be placed into the radix tree, and this adds a third. We rely on the fact that only one type of exceptional entry can be found in a given radix tree based on its usage. This happens for free with DAX vs shmem but we explicitly prevent shadow entries from being added to radix trees for DAX mappings. The only shadow entries that would be generated for DAX radix trees would be to track zero page mappings that were created for holes. These pages would receive minimal benefit from having shadow entries, and the choice to have only one type of exceptional entry in a given radix tree makes the logic simpler both in clear_exceptional_entry() and in the rest of DAX. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Dave Chinner <david@fromorbit.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.com> Cc: Jeff Layton <jlayton@poochiereds.net> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: fix kernel crash in khugepaged threadyalin wang2016-01-211-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This crash is caused by NULL pointer deference, in page_to_pfn() marco, when page == NULL : Unable to handle kernel NULL pointer dereference at virtual address 00000000 Internal error: Oops: 94000006 [#1] SMP Modules linked in: CPU: 1 PID: 26 Comm: khugepaged Tainted: G W 4.3.0-rc6-next-20151022ajb-00001-g32f3386-dirty #3 PC is at khugepaged+0x378/0x1af8 LR is at khugepaged+0x418/0x1af8 Process khugepaged (pid: 26, stack limit = 0xffffffc079638020) Call trace: khugepaged+0x378/0x1af8 kthread+0xdc/0xf4 ret_from_fork+0xc/0x40 Code: 35001700 f0002c60 aa0703e3 f9009fa0 (f94000e0) ---[ end trace 637503d8e28ae69e ]--- Kernel panic - not syncing: Fatal exception CPU2: stopping CPU: 2 PID: 0 Comm: swapper/2 Tainted: G D W 4.3.0-rc6-next-20151022ajb-00001-g32f3386-dirty #3 Hardware name: linux,dummy-virt (DT) [akpm@linux-foundation.org: fix fat-fingered merge resolution] Signed-off-by: yalin wang <yalin.wang2010@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: fix mlock accoutingKirill A. Shutemov2016-01-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tetsuo Handa reported underflow of NR_MLOCK on munlock. Testcase: #include <stdio.h> #include <stdlib.h> #include <sys/mman.h> #define BASE ((void *)0x400000000000) #define SIZE (1UL << 21) int main(int argc, char *argv[]) { void *addr; system("grep Mlocked /proc/meminfo"); addr = mmap(BASE, SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_LOCKED | MAP_FIXED, -1, 0); if (addr == MAP_FAILED) printf("mmap() failed\n"), exit(1); munmap(addr, SIZE); system("grep Mlocked /proc/meminfo"); return 0; } It happens on munlock_vma_page() due to unfortunate choice of nr_pages data type: __mod_zone_page_state(zone, NR_MLOCK, -nr_pages); For unsigned int nr_pages, implicitly casted to long in __mod_zone_page_state(), it becomes something around UINT_MAX. munlock_vma_page() usually called for THP as small pages go though pagevec. Let's make nr_pages signed int. Similar fixes in 6cdb18ad98a4 ("mm/vmstat: fix overflow in mod_zone_page_state()") used `long' type, but `int' here is OK for a count of the number of sub-pages in a huge page. Fixes: ff6a6da60b89 ("mm: accelerate munlock() treatment of THP pages") Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Michel Lespinasse <walken@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> [4.4+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | thp: change pmd_trans_huge_lock() interface to return ptlKirill A. Shutemov2016-01-213-13/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After THP refcounting rework we have only two possible return values from pmd_trans_huge_lock(): success and failure. Return-by-pointer for ptl doesn't make much sense in this case. Let's convert pmd_trans_huge_lock() to return ptl on success and NULL on failure. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Minchan Kim <minchan@kernel.org> 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>
* | mm: memcontrol: add "sock" to cgroup2 memory.statJohannes Weiner2016-01-201-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | Provide statistics on how much of a cgroup's memory footprint is made up of socket buffers from network connections owned by the group. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: basic memory statistics in cgroup2 memory controllerJohannes Weiner2016-01-201-0/+68
| | | | | | | | | | | | | | | | | | | | | | | | Provide a cgroup2 memory.stat that provides statistics on LRU memory and fault event counters. More consumers and breakdowns will follow. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: do not uncharge old page in page cache replacementJohannes Weiner2016-01-201-11/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Changing page->mem_cgroup of a live page is tricky and fragile. In particular, the memcg writeback code relies on that mapping being stable and users of mem_cgroup_replace_page() not overlapping with dirtyable inodes. Page cache replacement doesn't have to do that, though. Instead of being clever and transferring the charge from the old page to the new, force-charge the new page and leave the old page alone. A temporary overcharge won't matter in practice, and the old page is going to be freed shortly after this anyway. And this is not performance critical. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: free swap cache aggressively if memcg swap is fullVladimir Davydov2016-01-204-3/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Swap cache pages are freed aggressively if swap is nearly full (>50% currently), because otherwise we are likely to stop scanning anonymous when we near the swap limit even if there is plenty of freeable swap cache pages. We should follow the same trend in case of memory cgroup, which has its own swap limit. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: vmscan: do not scan anon pages if memcg swap limit is hitVladimir Davydov2016-01-202-1/+14
| | | | | | | | | | | | | | | | | | | | | | We don't scan anonymous memory if we ran out of swap, neither should we do it in case memcg swap limit is hit, because swap out is impossible anyway. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: replace mem_cgroup_lruvec_online with mem_cgroup_onlineVladimir Davydov2016-01-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | mem_cgroup_lruvec_online() takes lruvec, but it only needs memcg. Since get_scan_count(), which is the only user of this function, now possesses pointer to memcg, let's pass memcg directly to mem_cgroup_online() instead of picking it out of lruvec and rename the function accordingly. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: vmscan: pass memcg to get_scan_count()Vladimir Davydov2016-01-201-12/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | memcg will come in handy in get_scan_count(). It can already be used for getting swappiness immediately in get_scan_count() instead of passing it around. The following patches will add more memcg-related values, which will be used there. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: charge swap to cgroup2Vladimir Davydov2016-01-204-10/+121
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patchset introduces swap accounting to cgroup2. This patch (of 7): In the legacy hierarchy we charge memsw, which is dubious, because: - memsw.limit must be >= memory.limit, so it is impossible to limit swap usage less than memory usage. Taking into account the fact that the primary limiting mechanism in the unified hierarchy is memory.high while memory.limit is either left unset or set to a very large value, moving memsw.limit knob to the unified hierarchy would effectively make it impossible to limit swap usage according to the user preference. - memsw.usage != memory.usage + swap.usage, because a page occupying both swap entry and a swap cache page is charged only once to memsw counter. As a result, it is possible to effectively eat up to memory.limit of memory pages *and* memsw.limit of swap entries, which looks unexpected. That said, we should provide a different swap limiting mechanism for cgroup2. This patch adds mem_cgroup->swap counter, which charges the actual number of swap entries used by a cgroup. It is only charged in the unified hierarchy, while the legacy hierarchy memsw logic is left intact. The swap usage can be monitored using new memory.swap.current file and limited using memory.swap.max. Note, to charge swap resource properly in the unified hierarchy, we have to make swap_entry_free uncharge swap only when ->usage reaches zero, not just ->count, i.e. when all references to a swap entry, including the one taken by swap cache, are gone. This is necessary, because otherwise swap-in could result in uncharging swap even if the page is still in swap cache and hence still occupies a swap entry. At the same time, this shouldn't break memsw counter logic, where a page is never charged twice for using both memory and swap, because in case of legacy hierarchy we uncharge swap on commit (see mem_cgroup_commit_charge). Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: clean up alloc, online, offline, free functionsJohannes Weiner2016-01-201-173/+84
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The creation and teardown of struct mem_cgroup is fairly messy and that has attracted mistakes and subtle bugs before. The main cause for this is that there is no clear model about what needs to happen when, and that attracts more chaos. So create one: 1. mem_cgroup_alloc() should allocate struct mem_cgroup and its auxiliary members and initialize work items, locks etc. so that the object it returns is fully initialized and in a neutral state. 2. mem_cgroup_css_alloc() will use mem_cgroup_alloc() to obtain a new memcg object and configure it and the system according to the role of the new memory-controlled cgroup in the hierarchy. 3. mem_cgroup_css_online() is no longer needed to synchronize with iterators, but it verifies css->id which isn't available earlier. 4. mem_cgroup_css_offline() implements stuff that needs to happen upon the user-visible destruction of a cgroup, which includes stopping all user interfacing as well as releasing certain structures when continued memory consumption would be unexpected at that point. 5. mem_cgroup_css_free() prepares the system and the memcg object for the object's disappearance, neutralizes its state, and then gives it back to mem_cgroup_free(). 6. mem_cgroup_free() releases struct mem_cgroup and auxiliary memory. [arnd@arndb.de: fix SLOB build regression] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: flatten struct cg_protoJohannes Weiner2016-01-201-18/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There are no more external users of struct cg_proto, flatten the structure into struct mem_cgroup. Since using those struct members doesn't stand out as much anymore, add cgroup2 static branches to make it clearer which code is legacy. Suggested-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: rein in the CONFIG space madnessJohannes Weiner2016-01-202-51/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | What CONFIG_INET and CONFIG_LEGACY_KMEM guard inside the memory controller code is insignificant, having these conditionals is not worth the complication and fragility that comes with them. [akpm@linux-foundation.org: rework mem_cgroup_css_free() statement ordering] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | net: drop tcp_memcontrol.cVladimir Davydov2016-01-201-8/+90
| | | | | | | | | | | | | | | | | | | | | | | | | | | | tcp_memcontrol.c only contains legacy memory.tcp.kmem.* file definitions and mem_cgroup->tcp_mem init/destroy stuff. This doesn't belong to network subsys. Let's move it to memcontrol.c. This also allows us to reuse generic code for handling legacy memcg files. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: "David S. Miller" <davem@davemloft.net> 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>
* | mm: memcontrol: introduce CONFIG_MEMCG_LEGACY_KMEMJohannes Weiner2016-01-202-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Let the user know that CONFIG_MEMCG_KMEM does not apply to the cgroup2 interface. This also makes legacy-only code sections stand out better. [arnd@arndb.de: mm: memcontrol: only manage socket pressure for CONFIG_INET] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: allow to disable kmem accounting for cgroup2Vladimir Davydov2016-01-201-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Kmem accounting might incur overhead that some users can't put up with. Besides, the implementation is still considered unstable. So let's provide a way to disable it for those users who aren't happy with it. To disable kmem accounting for cgroup2, pass cgroup.memory=nokmem at boot time. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: account "kmem" consumers in cgroup2 memory controllerJohannes Weiner2016-01-201-7/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The original cgroup memory controller has an extension to account slab memory (and other "kernel memory" consumers) in a separate "kmem" counter, once the user set an explicit limit on that "kmem" pool. However, this includes various consumers whose sizes are directly linked to userspace activity. Accounting them as an optional "kmem" extension is problematic for several reasons: 1. It leaves the main memory interface with incomplete semantics. A user who puts their workload into a cgroup and configures a memory limit does not expect us to leave holes in the containment as big as the dentry and inode cache, or the kernel stack pages. 2. If the limit set on this random historical subgroup of consumers is reached, subsequent allocations will fail even when the main memory pool available to the cgroup is not yet exhausted and/or has reclaimable memory in it. 3. Calling it 'kernel memory' is misleading. The dentry and inode caches are no more 'kernel' (or no less 'user') memory than the page cache itself. Treating these consumers as different classes is a historical implementation detail that should not leak to users. So, in addition to page cache, anonymous memory, and network socket memory, account the following memory consumers per default in the cgroup2 memory controller: - threadinfo - task_struct - task_delay_info - pid - cred - mm_struct - vm_area_struct and vm_region (nommu) - anon_vma and anon_vma_chain - signal_struct - sighand_struct - fs_struct - files_struct - fdtable and fdtable->full_fds_bits - dentry and external_name - inode for all filesystems. This should give us reasonable memory isolation for most common workloads out of the box. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: move kmem accounting code to CONFIG_MEMCGJohannes Weiner2016-01-205-47/+60
| | | | | | | | | | | | | | | | | | | | | | | | The cgroup2 memory controller will account important in-kernel memory consumers per default. Move all necessary components to CONFIG_MEMCG. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: separate kmem code from legacy tcp accounting codeJohannes Weiner2016-01-201-21/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cgroup2 memory controller will include important in-kernel memory consumers per default, including socket memory, but it will no longer carry the historic tcp control interface. Separate the kmem state init from the tcp control interface init in preparation for that. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: group kmem init and exit functions togetherJohannes Weiner2016-01-201-81/+76
| | | | | | | | | | | | | | | | | | | | | | | | Put all the related code to setup and teardown the kmem accounting state into the same location. No functional change intended. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: give the kmem states more descriptive namesJohannes Weiner2016-01-203-30/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On any given memcg, the kmem accounting feature has three separate states: not initialized, structures allocated, and actively accounting slab memory. These are represented through a combination of the kmem_acct_activated and kmem_acct_active flags, which is confusing. Convert to a kmem_state enum with the states NONE, ALLOCATED, and ONLINE. Then rename the functions to modify the state accordingly. This follows the nomenclature of css object states more closely. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: remove double kmem page_counter initJohannes Weiner2016-01-201-14/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | The kmem page_counter's limit is initialized to PAGE_COUNTER_MAX inside mem_cgroup_css_online(). There is no need to repeat this from memcg_propagate_kmem(). Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: drop unused @css argument in memcg_init_kmemJohannes Weiner2016-01-201-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This series adds accounting of the historical "kmem" memory consumers to the cgroup2 memory controller. These consumers include the dentry cache, the inode cache, kernel stack pages, and a few others that are pointed out in patch 7/8. The footprint of these consumers is directly tied to userspace activity in common workloads, and so they have to be part of the minimally viable configuration in order to present a complete feature to our users. The cgroup2 interface of the memory controller is far from complete, but this series, along with the socket memory accounting series, provides the final semantic changes for the existing memory knobs in the cgroup2 interface, which is scheduled for initial release in the next merge window. This patch (of 8): Remove unused css argument frmo memcg_init_kmem() Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc read mm's {arg,env}_{start,end} with mmap semaphore taken.Mateusz Guzik2016-01-201-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Only functions doing more than one read are modified. Consumeres happened to deal with possibly changing data, but it does not seem like a good thing to rely on. Signed-off-by: Mateusz Guzik <mguzik@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Jarod Wilson <jarod@redhat.com> Cc: Jan Stancek <jstancek@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anshuman Khandual <anshuman.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | UBSAN: run-time undefined behavior sanity checkerAndrey Ryabinin2016-01-201-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | UBSAN uses compile-time instrumentation to catch undefined behavior (UB). Compiler inserts code that perform certain kinds of checks before operations that could cause UB. If check fails (i.e. UB detected) __ubsan_handle_* function called to print error message. So the most of the work is done by compiler. This patch just implements ubsan handlers printing errors. GCC has this capability since 4.9.x [1] (see -fsanitize=undefined option and its suboptions). However GCC 5.x has more checkers implemented [2]. Article [3] has a bit more details about UBSAN in the GCC. [1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html [2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html [3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/ Issues which UBSAN has found thus far are: Found bugs: * out-of-bounds access - 97840cb67ff5 ("netfilter: nfnetlink: fix insufficient validation in nfnetlink_bind") undefined shifts: * d48458d4a768 ("jbd2: use a better hash function for the revoke table") * 10632008b9e1 ("clockevents: Prevent shift out of bounds") * 'x << -1' shift in ext4 - http://lkml.kernel.org/r/<5444EF21.8020501@samsung.com> * undefined rol32(0) - http://lkml.kernel.org/r/<1449198241-20654-1-git-send-email-sasha.levin@oracle.com> * undefined dirty_ratelimit calculation - http://lkml.kernel.org/r/<566594E2.3050306@odin.com> * undefined roundown_pow_of_two(0) - http://lkml.kernel.org/r/<1449156616-11474-1-git-send-email-sasha.levin@oracle.com> * [WONTFIX] undefined shift in __bpf_prog_run - http://lkml.kernel.org/r/<CACT4Y+ZxoR3UjLgcNdUm4fECLMx2VdtfrENMtRRCdgHB2n0bJA@mail.gmail.com> WONTFIX here because it should be fixed in bpf program, not in kernel. signed overflows: * 32a8df4e0b33f ("sched: Fix odd values in effective_load() calculations") * mul overflow in ntp - http://lkml.kernel.org/r/<1449175608-1146-1-git-send-email-sasha.levin@oracle.com> * incorrect conversion into rtc_time in rtc_time64_to_tm() - http://lkml.kernel.org/r/<1449187944-11730-1-git-send-email-sasha.levin@oracle.com> * unvalidated timespec in io_getevents() - http://lkml.kernel.org/r/<CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com> * [NOTABUG] signed overflow in ktime_add_safe() - http://lkml.kernel.org/r/<CACT4Y+aJ4muRnWxsUe1CMnA6P8nooO33kwG-c8YZg=0Xc8rJqw@mail.gmail.com> [akpm@linux-foundation.org: fix unused local warning] [akpm@linux-foundation.org: fix __int128 build woes] Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Marek <mmarek@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yury Gribov <y.gribov@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | ptrace: use fsuid, fsgid, effective creds for fs access checksJann Horn2016-01-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By checking the effective credentials instead of the real UID / permitted capabilities, ensure that the calling process actually intended to use its credentials. To ensure that all ptrace checks use the correct caller credentials (e.g. in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS flag), use two new flags and require one of them to be set. The problem was that when a privileged task had temporarily dropped its privileges, e.g. by calling setreuid(0, user_uid), with the intent to perform following syscalls with the credentials of a user, it still passed ptrace access checks that the user would not be able to pass. While an attacker should not be able to convince the privileged task to perform a ptrace() syscall, this is a problem because the ptrace access check is reused for things in procfs. In particular, the following somewhat interesting procfs entries only rely on ptrace access checks: /proc/$pid/stat - uses the check for determining whether pointers should be visible, useful for bypassing ASLR /proc/$pid/maps - also useful for bypassing ASLR /proc/$pid/cwd - useful for gaining access to restricted directories that contain files with lax permissions, e.g. in this scenario: lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar drwx------ root root /root drwxr-xr-x root root /root/foobar -rw-r--r-- root root /root/foobar/secret Therefore, on a system where a root-owned mode 6755 binary changes its effective credentials as described and then dumps a user-specified file, this could be used by an attacker to reveal the memory layout of root's processes or reveal the contents of files he is not allowed to access (through /proc/$pid/cwd). [akpm@linux-foundation.org: fix warning] Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | zsmalloc: fix migrate_zspage-zs_free race conditionJunil Lee2016-01-201-1/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | record_obj() in migrate_zspage() does not preserve handle's HANDLE_PIN_BIT, set by find_aloced_obj()->trypin_tag(), and implicitly (accidentally) un-pins the handle, while migrate_zspage() still performs an explicit unpin_tag() on the that handle. This additional explicit unpin_tag() introduces a race condition with zs_free(), which can pin that handle by this time, so the handle becomes un-pinned. Schematically, it goes like this: CPU0 CPU1 migrate_zspage find_alloced_obj trypin_tag set HANDLE_PIN_BIT zs_free() pin_tag() obj_malloc() -- new object, no tag record_obj() -- remove HANDLE_PIN_BIT set HANDLE_PIN_BIT unpin_tag() -- remove zs_free's HANDLE_PIN_BIT The race condition may result in a NULL pointer dereference: Unable to handle kernel NULL pointer dereference at virtual address 00000000 CPU: 0 PID: 19001 Comm: CookieMonsterCl Tainted: PC is at get_zspage_mapping+0x0/0x24 LR is at obj_free.isra.22+0x64/0x128 Call trace: get_zspage_mapping+0x0/0x24 zs_free+0x88/0x114 zram_free_page+0x64/0xcc zram_slot_free_notify+0x90/0x108 swap_entry_free+0x278/0x294 free_swap_and_cache+0x38/0x11c unmap_single_vma+0x480/0x5c8 unmap_vmas+0x44/0x60 exit_mmap+0x50/0x110 mmput+0x58/0xe0 do_exit+0x320/0x8dc do_group_exit+0x44/0xa8 get_signal+0x538/0x580 do_signal+0x98/0x4b8 do_notify_resume+0x14/0x5c This patch keeps the lock bit in migration path and update value atomically. Signed-off-by: Junil Lee <junil0814.lee@lge.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: <stable@vger.kernel.org> [4.1+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | thp: fix interrupt unsafe locking in split_huge_page()Kirill A. Shutemov2016-01-201-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | split_queue_lock can be taken from interrupt context in some cases, but I forgot to convert locking in split_huge_page() to interrupt-safe primitives. Let's fix this. lockdep output: ====================================================== [ INFO: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected ] 4.4.0+ #259 Tainted: G W ------------------------------------------------------ syz-executor/18183 [HC0[0]:SC0[2]:HE0:SE0] is trying to acquire: (split_queue_lock){+.+...}, at: free_transhuge_page+0x24/0x90 mm/huge_memory.c:3436 and this task is already holding: (slock-AF_INET){+.-...}, at: spin_lock_bh include/linux/spinlock.h:307 (slock-AF_INET){+.-...}, at: lock_sock_fast+0x45/0x120 net/core/sock.c:2462 which would create a new lock dependency: (slock-AF_INET){+.-...} -> (split_queue_lock){+.+...} but this new dependency connects a SOFTIRQ-irq-safe lock: (slock-AF_INET){+.-...} ... which became SOFTIRQ-irq-safe at: mark_irqflags kernel/locking/lockdep.c:2799 __lock_acquire+0xfd8/0x4700 kernel/locking/lockdep.c:3162 lock_acquire+0x1dc/0x430 kernel/locking/lockdep.c:3585 __raw_spin_lock include/linux/spinlock_api_smp.h:144 _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:302 udp_queue_rcv_skb+0x781/0x1550 net/ipv4/udp.c:1680 flush_stack+0x50/0x330 net/ipv6/udp.c:799 __udp4_lib_mcast_deliver+0x694/0x7f0 net/ipv4/udp.c:1798 __udp4_lib_rcv+0x17dc/0x23e0 net/ipv4/udp.c:1888 udp_rcv+0x21/0x30 net/ipv4/udp.c:2108 ip_local_deliver_finish+0x2b3/0xa50 net/ipv4/ip_input.c:216 NF_HOOK_THRESH include/linux/netfilter.h:226 NF_HOOK include/linux/netfilter.h:249 ip_local_deliver+0x1c4/0x2f0 net/ipv4/ip_input.c:257 dst_input include/net/dst.h:498 ip_rcv_finish+0x5ec/0x1730 net/ipv4/ip_input.c:365 NF_HOOK_THRESH include/linux/netfilter.h:226 NF_HOOK include/linux/netfilter.h:249 ip_rcv+0x963/0x1080 net/ipv4/ip_input.c:455 __netif_receive_skb_core+0x1620/0x2f80 net/core/dev.c:4154 __netif_receive_skb+0x2a/0x160 net/core/dev.c:4189 netif_receive_skb_internal+0x1b5/0x390 net/core/dev.c:4217 napi_skb_finish net/core/dev.c:4542 napi_gro_receive+0x2bd/0x3c0 net/core/dev.c:4572 e1000_clean_rx_irq+0x4e2/0x1100 drivers/net/ethernet/intel/e1000e/netdev.c:1038 e1000_clean+0xa08/0x24a0 drivers/net/ethernet/intel/e1000/e1000_main.c:3819 napi_poll net/core/dev.c:5074 net_rx_action+0x7eb/0xdf0 net/core/dev.c:5139 __do_softirq+0x26a/0x920 kernel/softirq.c:273 invoke_softirq kernel/softirq.c:350 irq_exit+0x18f/0x1d0 kernel/softirq.c:391 exiting_irq ./arch/x86/include/asm/apic.h:659 do_IRQ+0x86/0x1a0 arch/x86/kernel/irq.c:252 ret_from_intr+0x0/0x20 arch/x86/entry/entry_64.S:520 arch_safe_halt ./arch/x86/include/asm/paravirt.h:117 default_idle+0x52/0x2e0 arch/x86/kernel/process.c:304 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:295 default_idle_call+0x48/0xa0 kernel/sched/idle.c:92 cpuidle_idle_call kernel/sched/idle.c:156 cpu_idle_loop kernel/sched/idle.c:252 cpu_startup_entry+0x554/0x710 kernel/sched/idle.c:300 rest_init+0x192/0x1a0 init/main.c:412 start_kernel+0x678/0x69e init/main.c:683 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:195 x86_64_start_kernel+0x158/0x167 arch/x86/kernel/head64.c:184 to a SOFTIRQ-irq-unsafe lock: (split_queue_lock){+.+...} which became SOFTIRQ-irq-unsafe at: mark_irqflags kernel/locking/lockdep.c:2817 __lock_acquire+0x146e/0x4700 kernel/locking/lockdep.c:3162 lock_acquire+0x1dc/0x430 kernel/locking/lockdep.c:3585 __raw_spin_lock include/linux/spinlock_api_smp.h:144 _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:302 split_huge_page_to_list+0xcc0/0x1c50 mm/huge_memory.c:3399 split_huge_page include/linux/huge_mm.h:99 queue_pages_pte_range+0xa38/0xef0 mm/mempolicy.c:507 walk_pmd_range mm/pagewalk.c:50 walk_pud_range mm/pagewalk.c:90 walk_pgd_range mm/pagewalk.c:116 __walk_page_range+0x653/0xcd0 mm/pagewalk.c:204 walk_page_range+0xfe/0x2b0 mm/pagewalk.c:281 queue_pages_range+0xfb/0x130 mm/mempolicy.c:687 migrate_to_node mm/mempolicy.c:1004 do_migrate_pages+0x370/0x4e0 mm/mempolicy.c:1109 SYSC_migrate_pages mm/mempolicy.c:1453 SyS_migrate_pages+0x640/0x730 mm/mempolicy.c:1374 entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(split_queue_lock); local_irq_disable(); lock(slock-AF_INET); lock(split_queue_lock); <Interrupt> lock(slock-AF_INET); Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: avoid uninitialized variable in tracepointArnd Bergmann2016-01-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A newly added tracepoint in the hugepage code uses a variable in the error handling that is not initialized at that point: include/trace/events/huge_memory.h:81:230: error: 'isolated' may be used uninitialized in this function [-Werror=maybe-uninitialized] The result is relatively harmless, as the trace data will in rare cases contain incorrect data. This works around the problem by adding an explicit initialization. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 7d2eba0557c1 ("mm: add tracepoint for scanning pages") Reviewed-by: Ebru Akagunduz <ebru.akagunduz@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds2016-01-181-2/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull virtio barrier rework+fixes from Michael Tsirkin: "This adds a new kind of barrier, and reworks virtio and xen to use it. Plus some fixes here and there" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (44 commits) checkpatch: add virt barriers checkpatch: check for __smp outside barrier.h checkpatch.pl: add missing memory barriers virtio: make find_vqs() checkpatch.pl-friendly virtio_balloon: fix race between migration and ballooning virtio_balloon: fix race by fill and leak s390: more efficient smp barriers s390: use generic memory barriers xen/events: use virt_xxx barriers xen/io: use virt_xxx barriers xenbus: use virt_xxx barriers virtio_ring: use virt_store_mb sh: move xchg_cmpxchg to a header by itself sh: support 1 and 2 byte xchg virtio_ring: update weak barriers to use virt_xxx Revert "virtio_ring: Update weak barriers to use dma_wmb/rmb" asm-generic: implement virt_xxx memory barriers x86: define __smp_xxx xtensa: define __smp_xxx tile: define __smp_xxx ...
| * | virtio_balloon: fix race between migration and ballooningMinchan Kim2016-01-121-2/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In balloon_page_dequeue, pages_lock should cover the loop (ie, list_for_each_entry_safe). Otherwise, the cursor page could be isolated by compaction and then list_del by isolation could poison the page->lru.{prev,next} so the loop finally could access wrong address like this. This patch fixes the bug. general protection fault: 0000 [#1] SMP Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 2 PID: 82 Comm: vballoon Not tainted 4.4.0-rc5-mm1-access_bit+ #1906 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff8800a7ff0000 ti: ffff8800a7fec000 task.ti: ffff8800a7fec000 RIP: 0010:[<ffffffff8115e754>] [<ffffffff8115e754>] balloon_page_dequeue+0x54/0x130 RSP: 0018:ffff8800a7fefdc0 EFLAGS: 00010246 RAX: ffff88013fff9a70 RBX: ffffea000056fe00 RCX: 0000000000002b7d RDX: ffff88013fff9a70 RSI: ffffea000056fe00 RDI: ffff88013fff9a68 RBP: ffff8800a7fefde8 R08: ffffea000056fda0 R09: 0000000000000000 R10: ffff8800a7fefd90 R11: 0000000000000001 R12: dead0000000000e0 R13: ffffea000056fe20 R14: ffff880138809070 R15: ffff880138809060 FS: 0000000000000000(0000) GS:ffff88013fc40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007f229c10e000 CR3: 00000000b8b53000 CR4: 00000000000006a0 Stack: 0000000000000100 ffff880138809088 ffff880138809000 ffff880138809060 0000000000000046 ffff8800a7fefe28 ffffffff812c86d3 ffff880138809020 ffff880138809000 fffffffffff91900 0000000000000100 ffff880138809060 Call Trace: [<ffffffff812c86d3>] leak_balloon+0x93/0x1a0 [<ffffffff812c8bc7>] balloon+0x217/0x2a0 [<ffffffff8143739e>] ? __schedule+0x31e/0x8b0 [<ffffffff81078160>] ? abort_exclusive_wait+0xb0/0xb0 [<ffffffff812c89b0>] ? update_balloon_stats+0xf0/0xf0 [<ffffffff8105b6e9>] kthread+0xc9/0xe0 [<ffffffff8105b620>] ? kthread_park+0x60/0x60 [<ffffffff8143b4af>] ret_from_fork+0x3f/0x70 [<ffffffff8105b620>] ? kthread_park+0x60/0x60 Code: 8d 60 e0 0f 84 af 00 00 00 48 8b 43 20 a8 01 75 3b 48 89 d8 f0 0f ba 28 00 72 10 48 8b 03 f6 c4 08 75 2f 48 89 df e8 8c 83 f9 ff <49> 8b 44 24 20 4d 8d 6c 24 20 48 83 e8 20 4d 39 f5 74 7a 4c 89 RIP [<ffffffff8115e754>] balloon_page_dequeue+0x54/0x130 RSP <ffff8800a7fefdc0> ---[ end trace 43cf28060d708d5f ]--- Kernel panic - not syncing: Fatal exception Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Cc: <stable@vger.kernel.org> Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Rafael Aquini <aquini@redhat.com>
* | vm: fix incorrect unlock error path in madvise_free_huge_pmdLinus Torvalds2016-01-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Commit b8d3c4c3009d ("mm/huge_memory.c: don't split THP page when MADV_FREE syscall is called") introduced this new function, but got the error handling for when pmd_trans_huge_lock() fails wrong. In the failure case, the lock has not been taken, and we should not unlock on the way out. Cc: Minchan Kim <minchan@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memcg: only free spare array when readers are doneMartijn Coenen2016-01-151-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A spare array holding mem cgroup threshold events is kept around to make sure we can always safely deregister an event and have an array to store the new set of events in. In the scenario where we're going from 1 to 0 registered events, the pointer to the primary array containing 1 event is copied to the spare slot, and then the spare slot is freed because no events are left. However, it is freed before calling synchronize_rcu(), which means readers may still be accessing threshold->primary after it is freed. Fixed by only freeing after synchronize_rcu(). Signed-off-by: Martijn Coenen <maco@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: soft-offline: exit with failure for non anonymous thpNaoya Horiguchi2016-01-151-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently memory_failure() doesn't handle non anonymous thp case, because we can hardly expect the error handling to be successful, and it can just hit some corner case which results in BUG_ON or something severe like that. This is also the case for soft offline code, so let's make it in the same way. Orignal code has a MF_COUNT_INCREASED check before put_hwpoison_page(), but it's unnecessary because get_any_page() is already called when running on this code, which takes a refcount of the target page regardress of the flag. So this patch also removes it. [akpm@linux-foundation.org: fix build] Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: soft-offline: clean up soft_offline_page()Naoya Horiguchi2016-01-151-31/+47
| | | | | | | | | | | | | | | | | | | | | | soft_offline_page() has some deeply indented code, that's the sign of demand for cleanup. So let's do this. No functionality change. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: make swapoff more robust against soft dirtyHugh Dickins2016-01-151-14/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both s390 and powerpc have hit the issue of swapoff hanging, when CONFIG_HAVE_ARCH_SOFT_DIRTY and CONFIG_MEM_SOFT_DIRTY ifdefs were not quite as x86_64 had them. I think it would be much clearer if HAVE_ARCH_SOFT_DIRTY was just a Kconfig option set by architectures to determine whether the MEM_SOFT_DIRTY option should be offered, and the actual code depend upon CONFIG_MEM_SOFT_DIRTY alone. But won't embark on that change myself: instead make swapoff more robust, by using pte_swp_clear_soft_dirty() on each pte it encounters, without an explicit #ifdef CONFIG_MEM_SOFT_DIRTY. That being a no-op, whether the bit in question is defined as 0 or the asm-generic fallback is used, unless soft dirty is fully turned on. Why "maybe" in maybe_same_pte()? Rename it pte_same_as_swp(). Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: fix locking order in mm_take_all_locks()Kirill A. Shutemov2016-01-152-20/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dmitry Vyukov has reported[1] possible deadlock (triggered by his syzkaller fuzzer): Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&hugetlbfs_i_mmap_rwsem_key); lock(&mapping->i_mmap_rwsem); lock(&hugetlbfs_i_mmap_rwsem_key); lock(&mapping->i_mmap_rwsem); Both traces points to mm_take_all_locks() as a source of the problem. It doesn't take care about ordering or hugetlbfs_i_mmap_rwsem_key (aka mapping->i_mmap_rwsem for hugetlb mapping) vs. i_mmap_rwsem. huge_pmd_share() does memory allocation under hugetlbfs_i_mmap_rwsem_key and allocator can take i_mmap_rwsem if it hit reclaim. So we need to take i_mmap_rwsem from all hugetlb VMAs before taking i_mmap_rwsem from rest of VMAs. The patch also documents locking order for hugetlbfs_i_mmap_rwsem_key. [1] http://lkml.kernel.org/r/CACT4Y+Zu95tBs-0EvdiAKzUOsb4tczRRfCRTpLr4bg_OP9HuVg@mail.gmail.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: mempolicy: skip non-migratable VMAs when setting MPOL_MF_LAZYLiang Chen2016-01-151-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MPOL_MF_LAZY is not visible from userspace since a720094ded8c ("mm: mempolicy: Hide MPOL_NOOP and MPOL_MF_LAZY from userspace for now"), but it should still skip non-migratable VMAs such as VM_IO, VM_PFNMAP, and VM_HUGETLB VMAs, and avoid useless overhead of minor faults. Signed-off-by: Liang Chen <liangchen.linux@gmail.com> Signed-off-by: Gavin Guo <gavin.guo@canonical.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andi Kleen <andi@firstfloor.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-06 04:59:22 +0000