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2021-09-24mm: fix uninitialized use in overcommit_policy_handlerChen Jun1-2/+2
We get an unexpected value of /proc/sys/vm/overcommit_memory after running the following program: int main() { int fd = open("/proc/sys/vm/overcommit_memory", O_RDWR); write(fd, "1", 1); write(fd, "2", 1); close(fd); } write(fd, "2", 1) will pass *ppos = 1 to proc_dointvec_minmax. proc_dointvec_minmax will return 0 without setting new_policy. t.data = &new_policy; ret = proc_dointvec_minmax(&t, write, buffer, lenp, ppos) -->do_proc_dointvec -->__do_proc_dointvec if (write) { if (proc_first_pos_non_zero_ignore(ppos, table)) goto out; sysctl_overcommit_memory = new_policy; so sysctl_overcommit_memory will be set to an uninitialized value. Check whether new_policy has been changed by proc_dointvec_minmax. Link: https://lkml.kernel.org/r/20210923020524.13289-1-chenjun102@huawei.com Fixes: 56f3547bfa4d ("mm: adjust vm_committed_as_batch according to vm overcommit policy") Signed-off-by: Chen Jun <chenjun102@huawei.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Rui Xiang <rui.xiang@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-02mm: don't allow oversized kvmalloc() callsLinus Torvalds1-0/+4
'kvmalloc()' is a convenience function for people who want to do a kmalloc() but fall back on vmalloc() if there aren't enough physically contiguous pages, or if the allocation is larger than what kmalloc() supports. However, let's make sure it doesn't get _too_ easy to do crazy things with it. In particular, don't allow big allocations that could be due to integer overflow or underflow. So make sure the allocation size fits in an 'int', to protect against trivial integer conversion issues. Acked-by: Willy Tarreau <w@1wt.eu> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-09mm: Add kvrealloc()Dave Chinner1-0/+15
During log recovery of an XFS filesystem with 64kB directory buffers, rebuilding a buffer split across two log records results in a memory allocation warning from krealloc like this: xfs filesystem being mounted at /mnt/scratch supports timestamps until 2038 (0x7fffffff) XFS (dm-0): Unmounting Filesystem XFS (dm-0): Mounting V5 Filesystem XFS (dm-0): Starting recovery (logdev: internal) ------------[ cut here ]------------ WARNING: CPU: 5 PID: 3435170 at mm/page_alloc.c:3539 get_page_from_freelist+0xdee/0xe40 ..... RIP: 0010:get_page_from_freelist+0xdee/0xe40 Call Trace: ? complete+0x3f/0x50 __alloc_pages+0x16f/0x300 alloc_pages+0x87/0x110 kmalloc_order+0x2c/0x90 kmalloc_order_trace+0x1d/0x90 __kmalloc_track_caller+0x215/0x270 ? xlog_recover_add_to_cont_trans+0x63/0x1f0 krealloc+0x54/0xb0 xlog_recover_add_to_cont_trans+0x63/0x1f0 xlog_recovery_process_trans+0xc1/0xd0 xlog_recover_process_ophdr+0x86/0x130 xlog_recover_process_data+0x9f/0x160 xlog_recover_process+0xa2/0x120 xlog_do_recovery_pass+0x40b/0x7d0 ? __irq_work_queue_local+0x4f/0x60 ? irq_work_queue+0x3a/0x50 xlog_do_log_recovery+0x70/0x150 xlog_do_recover+0x38/0x1d0 xlog_recover+0xd8/0x170 xfs_log_mount+0x181/0x300 xfs_mountfs+0x4a1/0x9b0 xfs_fs_fill_super+0x3c0/0x7b0 get_tree_bdev+0x171/0x270 ? suffix_kstrtoint.constprop.0+0xf0/0xf0 xfs_fs_get_tree+0x15/0x20 vfs_get_tree+0x24/0xc0 path_mount+0x2f5/0xaf0 __x64_sys_mount+0x108/0x140 do_syscall_64+0x3a/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xae Essentially, we are taking a multi-order allocation from kmem_alloc() (which has an open coded no fail, no warn loop) and then reallocating it out to 64kB using krealloc(__GFP_NOFAIL) and that is then triggering the above warning. This is a regression caused by converting this code from an open coded no fail/no warn reallocation loop to using __GFP_NOFAIL. What we actually need here is kvrealloc(), so that if contiguous page allocation fails we fall back to vmalloc() and we don't get nasty warnings happening in XFS. Fixes: 771915c4f688 ("xfs: remove kmem_realloc()") Signed-off-by: Dave Chinner <dchinner@redhat.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-07-12mm: Make copy_huge_page() always availableMatthew Wilcox (Oracle)1-0/+10
Rewrite copy_huge_page() and move it into mm/util.c so it's always available. Fixes an exposure of uninitialised memory on configurations with HUGETLB and UFFD enabled and MIGRATION disabled. Fixes: 8cc5fcbb5be8 ("mm, hugetlb: fix racy resv_huge_pages underflow on UFFDIO_COPY") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-04Merge branch 'core-rcu-2021.07.04' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull RCU updates from Paul McKenney: - Bitmap parsing support for "all" as an alias for all bits - Documentation updates - Miscellaneous fixes, including some that overlap into mm and lockdep - kvfree_rcu() updates - mem_dump_obj() updates, with acks from one of the slab-allocator maintainers - RCU NOCB CPU updates, including limited deoffloading - SRCU updates - Tasks-RCU updates - Torture-test updates * 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (78 commits) tasks-rcu: Make show_rcu_tasks_gp_kthreads() be static inline rcu-tasks: Make ksoftirqd provide RCU Tasks quiescent states rcu: Add missing __releases() annotation rcu: Remove obsolete rcu_read_unlock() deadlock commentary rcu: Improve comments describing RCU read-side critical sections rcu: Create an unrcu_pointer() to remove __rcu from a pointer srcu: Early test SRCU polling start rcu: Fix various typos in comments rcu/nocb: Unify timers rcu/nocb: Prepare for fine-grained deferred wakeup rcu/nocb: Only cancel nocb timer if not polling rcu/nocb: Delete bypass_timer upon nocb_gp wakeup rcu/nocb: Cancel nocb_timer upon nocb_gp wakeup rcu/nocb: Allow de-offloading rdp leader rcu/nocb: Directly call __wake_nocb_gp() from bypass timer rcu: Don't penalize priority boosting when there is nothing to boost rcu: Point to documentation of ordering guarantees rcu: Make rcu_gp_cleanup() be noinline for tracing rcu: Restrict RCU_STRICT_GRACE_PERIOD to at most four CPUs rcu: Make show_rcu_gp_kthreads() dump rcu_node structures blocking GP ...
2021-06-30mm: introduce page_offline_(begin|end|freeze|thaw) to synchronize setting ↵David Hildenbrand1-0/+40
PageOffline() A driver might set a page logically offline -- PageOffline() -- and turn the page inaccessible in the hypervisor; after that, access to page content can be fatal. One example is virtio-mem; while unplugged memory -- marked as PageOffline() can currently be read in the hypervisor, this will no longer be the case in the future; for example, when having a virtio-mem device backed by huge pages in the hypervisor. Some special PFN walkers -- i.e., /proc/kcore -- read content of random pages after checking PageOffline(); however, these PFN walkers can race with drivers that set PageOffline(). Let's introduce page_offline_(begin|end|freeze|thaw) for synchronizing. page_offline_freeze()/page_offline_thaw() allows for a subsystem to synchronize with such drivers, achieving that a page cannot be set PageOffline() while frozen. page_offline_begin()/page_offline_end() is used by drivers that care about such races when setting a page PageOffline(). For simplicity, use a rwsem for now; neither drivers nor users are performance sensitive. Link: https://lkml.kernel.org/r/20210526093041.8800-5-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Aili Yao <yaoaili@kingsoft.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jiri Bohac <jbohac@suse.cz> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Roman Gushchin <guro@fb.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Steven Price <steven.price@arm.com> Cc: Wei Liu <wei.liu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-10mm/slub: Add Support for free path information of an objectManinder Singh1-1/+1
This commit adds enables a stack dump for the last free of an object: slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 0 size 64 allocated at meminfo_proc_show+0x40/0x4fc [ 20.192078] meminfo_proc_show+0x40/0x4fc [ 20.192263] seq_read_iter+0x18c/0x4c4 [ 20.192430] proc_reg_read_iter+0x84/0xac [ 20.192617] generic_file_splice_read+0xe8/0x17c [ 20.192816] splice_direct_to_actor+0xb8/0x290 [ 20.193008] do_splice_direct+0xa0/0xe0 [ 20.193185] do_sendfile+0x2d0/0x438 [ 20.193345] sys_sendfile64+0x12c/0x140 [ 20.193523] ret_fast_syscall+0x0/0x58 [ 20.193695] 0xbeeacde4 [ 20.193822] Free path: [ 20.193935] meminfo_proc_show+0x5c/0x4fc [ 20.194115] seq_read_iter+0x18c/0x4c4 [ 20.194285] proc_reg_read_iter+0x84/0xac [ 20.194475] generic_file_splice_read+0xe8/0x17c [ 20.194685] splice_direct_to_actor+0xb8/0x290 [ 20.194870] do_splice_direct+0xa0/0xe0 [ 20.195014] do_sendfile+0x2d0/0x438 [ 20.195174] sys_sendfile64+0x12c/0x140 [ 20.195336] ret_fast_syscall+0x0/0x58 [ 20.195491] 0xbeeacde4 Acked-by: Vlastimil Babka <vbabka@suse.cz> Co-developed-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-05-05mm/util.c: fix typoBhaskar Chowdhury1-1/+1
s/condtion/condition/ Link: https://lkml.kernel.org/r/20210317033439.3429411-1-unixbhaskar@gmail.com Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-05mm/util.c: reduce mem_dump_obj() object sizeJoe Perches1-10/+14
Simplify the code by using a temporary and reduce the object size by using a single call to pr_cont(). Reverse a test and unindent a block too. $ size mm/util.o* (defconfig x86-64) text data bss dec hex filename 7419 372 40 7831 1e97 mm/util.o.new 7477 372 40 7889 1ed1 mm/util.o.old Link: https://lkml.kernel.org/r/a6e105886338f68afd35f7a13d73bcf06b0cc732.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm: move page_mapping_file to pagemap.hMatthew Wilcox (Oracle)1-10/+0
page_mapping_file() is only used by some architectures, and then it is usually only used in one place. Make it a static inline function so other architectures don't have to carry this dead code. Link: https://lkml.kernel.org/r/20210317123011.350118-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Huang Ying <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-08rcutorture: Add crude tests for mem_dump_obj()Paul E. McKenney1-0/+1
This commit adds a few crude tests for mem_dump_obj() to rcutorture runs. Just to prevent bitrot, you understand! Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-03-08mm: Don't build mm_dump_obj() on CONFIG_PRINTK=n kernelsPaul E. McKenney1-0/+2
The mem_dump_obj() functionality adds a few hundred bytes, which is a small price to pay. Except on kernels built with CONFIG_PRINTK=n, in which mem_dump_obj() messages will be suppressed. This commit therefore makes mem_dump_obj() be a static inline empty function on kernels built with CONFIG_PRINTK=n and excludes all of its support functions as well. This avoids kernel bloat on systems that cannot use mem_dump_obj(). Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <linux-mm@kvack.org> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-22mm: Make mem_dump_obj() handle vmalloc() memoryPaul E. McKenney1-6/+8
This commit adds vmalloc() support to mem_dump_obj(). Note that the vmalloc_dump_obj() function combines the checking and dumping, in contrast with the split between kmem_valid_obj() and kmem_dump_obj(). The reason for the difference is that the checking in the vmalloc() case involves acquiring a global lock, and redundant acquisitions of global locks should be avoided, even on not-so-fast paths. Note that this change causes on-stack variables to be reported as vmalloc() storage from kernel_clone() or similar, depending on the degree of inlining that your compiler does. This is likely more helpful than the earlier "non-paged (local) memory". Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <linux-mm@kvack.org> Reported-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-22mm: Make mem_dump_obj() handle NULL and zero-sized pointersPaul E. McKenney1-1/+6
This commit makes mem_dump_obj() call out NULL and zero-sized pointers specially instead of classifying them as non-paged memory. Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <linux-mm@kvack.org> Reported-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-22mm: Add mem_dump_obj() to print source of memory blockPaul E. McKenney1-0/+24
There are kernel facilities such as per-CPU reference counts that give error messages in generic handlers or callbacks, whose messages are unenlightening. In the case of per-CPU reference-count underflow, this is not a problem when creating a new use of this facility because in that case the bug is almost certainly in the code implementing that new use. However, trouble arises when deploying across many systems, which might exercise corner cases that were not seen during development and testing. Here, it would be really nice to get some kind of hint as to which of several uses the underflow was caused by. This commit therefore exposes a mem_dump_obj() function that takes a pointer to memory (which must still be allocated if it has been dynamically allocated) and prints available information on where that memory came from. This pointer can reference the middle of the block as well as the beginning of the block, as needed by things like RCU callback functions and timer handlers that might not know where the beginning of the memory block is. These functions and handlers can use mem_dump_obj() to print out better hints as to where the problem might lie. The information printed can depend on kernel configuration. For example, the allocation return address can be printed only for slab and slub, and even then only when the necessary debug has been enabled. For slab, build with CONFIG_DEBUG_SLAB=y, and either use sizes with ample space to the next power of two or use the SLAB_STORE_USER when creating the kmem_cache structure. For slub, build with CONFIG_SLUB_DEBUG=y and boot with slub_debug=U, or pass SLAB_STORE_USER to kmem_cache_create() if more focused use is desired. Also for slub, use CONFIG_STACKTRACE to enable printing of the allocation-time stack trace. Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <linux-mm@kvack.org> Reported-by: Andrii Nakryiko <andrii@kernel.org> [ paulmck: Convert to printing and change names per Joonsoo Kim. ] [ paulmck: Move slab definition per Stephen Rothwell and kbuild test robot. ] [ paulmck: Handle CONFIG_MMU=n case where vmalloc() is kmalloc(). ] [ paulmck: Apply Vlastimil Babka feedback on slab.c kmem_provenance(). ] [ paulmck: Extract more info from !SLUB_DEBUG per Joonsoo Kim. ] [ paulmck: Explicitly check for small pointers per Naresh Kamboju. ] Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-11-19mm: introduce vma_set_file function v5Christian König1-0/+12
Add the new vma_set_file() function to allow changing vma->vm_file with the necessary refcount dance. v2: add more users of this. v3: add missing EXPORT_SYMBOL, rebase on mmap cleanup, add comments why we drop the reference on two occasions. v4: make it clear that changing an anonymous vma is illegal. v5: move vma_set_file to mm/util.c Signed-off-by: Christian König <christian.koenig@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v2) Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Link: https://patchwork.freedesktop.org/patch/399360/
2020-10-16mm/util.c: update the kerneldoc for kstrdup_const()Bartosz Golaszewski1-1/+2
Memory allocated with kstrdup_const() must not be passed to regular krealloc() as it is not aware of the possibility of the chunk residing in .rodata. Since there are no potential users of krealloc_const() at the moment, let's just update the doc to make it explicit. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200817173927.23389-1-brgl@bgdev.pl Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-04arm64: mte: Tags-aware aware memcmp_pages() implementationCatalin Marinas1-1/+1
When the Memory Tagging Extension is enabled, two pages are identical only if both their data and tags are identical. Make the generic memcmp_pages() a __weak function and add an arm64-specific implementation which returns non-zero if any of the two pages contain valid MTE tags (PG_mte_tagged set). There isn't much benefit in comparing the tags of two pages since these are normally used for heap allocations and likely to differ anyway. Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org>
2020-08-07mm: remove unnecessary wrapper function do_mmap_pgoff()Peter Collingbourne1-2/+2
The current split between do_mmap() and do_mmap_pgoff() was introduced in commit 1fcfd8db7f82 ("mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff()") to support MPX. The wrapper function do_mmap_pgoff() always passed 0 as the value of the vm_flags argument to do_mmap(). However, MPX support has subsequently been removed from the kernel and there were no more direct callers of do_mmap(); all calls were going via do_mmap_pgoff(). Simplify the code by removing do_mmap_pgoff() and changing all callers to directly call do_mmap(), which now no longer takes a vm_flags argument. Signed-off-by: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Link: http://lkml.kernel.org/r/20200727194109.1371462-1-pcc@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm: adjust vm_committed_as_batch according to vm overcommit policyFeng Tang1-0/+41
When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and lift it to 64X for OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Also add a sysctl handler to adjust it when the policy is reconfigured. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. We tested with test platforms in 0day (server, desktop and laptop), and 80%+ platforms shows improvements with that test. And whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. And if the lift is 16X, 1/3 of the platforms will show improvements, though it should help the mmap/unmap usage generally, as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit from : a larger batch. E.g. large in memory databases which do large mmaps : during startups from multiple threads. [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/ Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Kees Cook <keescook@chromium.org> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: kernel test robot <rong.a.chen@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1589611660-89854-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1592725000-73486-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-5-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm/util.c: make vm_memory_committed() more accurateFeng Tang1-1/+6
percpu_counter_sum_positive() will provide more accurate info. As with percpu_counter_read_positive(), in worst case the deviation could be 'batch * nr_cpus', which is totalram_pages/256 for now, and will be more when the batch gets enlarged. Its time cost is about 800 nanoseconds on a 2C/4T platform and 2~3 microseconds on a 2S/36C/72T Skylake server in normal case, and in worst case where vm_committed_as's spinlock is under severe contention, it costs 30~40 microseconds for the 2S/36C/72T Skylake sever, which should be fine for its only two users: /proc/meminfo and HyperV balloon driver's status trace per second. Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> # for /proc/meminfo Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: kernel test robot <rong.a.chen@intel.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1592725000-73486-3-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-3-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mmap locking API: convert mmap_sem commentsMichel Lespinasse1-1/+1
Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mmap locking API: add mmap_assert_locked() and mmap_assert_write_locked()Michel Lespinasse1-1/+1
Add new APIs to assert that mmap_sem is held. Using this instead of rwsem_is_locked and lockdep_assert_held[_write] makes the assertions more tolerant of future changes to the lock type. Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-10-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mmap locking API: use coccinelle to convert mmap_sem rwsem call sitesMichel Lespinasse1-4/+4
This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm: add kvfree_sensitive() for freeing sensitive data objectsWaiman Long1-0/+18
For kvmalloc'ed data object that contains sensitive information like cryptographic keys, we need to make sure that the buffer is always cleared before freeing it. Using memset() alone for buffer clearing may not provide certainty as the compiler may compile it away. To be sure, the special memzero_explicit() has to be used. This patch introduces a new kvfree_sensitive() for freeing those sensitive data objects allocated by kvmalloc(). The relevant places where kvfree_sensitive() can be used are modified to use it. Fixes: 4f0882491a14 ("KEYS: Avoid false positive ENOMEM error on key read") Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Joe Perches <joe@perches.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Rientjes <rientjes@google.com> Cc: Uladzislau Rezki <urezki@gmail.com> Link: http://lkml.kernel.org/r/20200407200318.11711-1-longman@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04mm/util.c: remove the VM_WARN_ONCE for vm_committed_as underflow checkFeng Tang1-4/+0
This check was added by commit 82f71ae4a2b8 ("mm: catch memory commitment underflow") in 2014 to have a safety check for issues which have been fixed. And there has been few report caught by it, as described in its commit log: : This shouldn't happen any more - the previous two patches fixed : the committed_as underflow issues. But it was really found by Qian Cai when he used the LTP memory stress suite to test a RFC patchset, which tries to improve scalability of per-cpu counter 'vm_committed_as', by chosing a bigger 'batch' number for loose overcommit policies (OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS), while keeping current number for OVERCOMMIT_NEVER. With that patchset, when system firstly uses a loose policy, the 'vm_committed_as' count could be a big negative value, as its big 'batch' number allows a big deviation, then when the policy is changed to OVERCOMMIT_NEVER, the 'batch' will be decreased to a much smaller value, thus hits this WARN check. To mitigate this, one proposed solution is to queue work on all online CPUs to do a local sync for 'vm_committed_as' when changing policy to OVERCOMMIT_NEVER, plus some global syncing to garante the case won't be hit. But this solution is costy and slow, given this check hasn't shown real trouble or benefit, simply drop it from one hot path of MM. And perf stats does show some tiny saving for removing it. Reported-by: Qian Cai <cai@lca.pw> Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Qian Cai <cai@lca.pw> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Kees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20200603094804.GB89848@shbuild999.sh.intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds1-6/+4
Pull networking updates from David Miller: 1) Allow setting bluetooth L2CAP modes via socket option, from Luiz Augusto von Dentz. 2) Add GSO partial support to igc, from Sasha Neftin. 3) Several cleanups and improvements to r8169 from Heiner Kallweit. 4) Add IF_OPER_TESTING link state and use it when ethtool triggers a device self-test. From Andrew Lunn. 5) Start moving away from custom driver versions, use the globally defined kernel version instead, from Leon Romanovsky. 6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin. 7) Allow hard IRQ deferral during NAPI, from Eric Dumazet. 8) Add sriov and vf support to hinic, from Luo bin. 9) Support Media Redundancy Protocol (MRP) in the bridging code, from Horatiu Vultur. 10) Support netmap in the nft_nat code, from Pablo Neira Ayuso. 11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina Dubroca. Also add ipv6 support for espintcp. 12) Lots of ReST conversions of the networking documentation, from Mauro Carvalho Chehab. 13) Support configuration of ethtool rxnfc flows in bcmgenet driver, from Doug Berger. 14) Allow to dump cgroup id and filter by it in inet_diag code, from Dmitry Yakunin. 15) Add infrastructure to export netlink attribute policies to userspace, from Johannes Berg. 16) Several optimizations to sch_fq scheduler, from Eric Dumazet. 17) Fallback to the default qdisc if qdisc init fails because otherwise a packet scheduler init failure will make a device inoperative. From Jesper Dangaard Brouer. 18) Several RISCV bpf jit optimizations, from Luke Nelson. 19) Correct the return type of the ->ndo_start_xmit() method in several drivers, it's netdev_tx_t but many drivers were using 'int'. From Yunjian Wang. 20) Add an ethtool interface for PHY master/slave config, from Oleksij Rempel. 21) Add BPF iterators, from Yonghang Song. 22) Add cable test infrastructure, including ethool interfaces, from Andrew Lunn. Marvell PHY driver is the first to support this facility. 23) Remove zero-length arrays all over, from Gustavo A. R. Silva. 24) Calculate and maintain an explicit frame size in XDP, from Jesper Dangaard Brouer. 25) Add CAP_BPF, from Alexei Starovoitov. 26) Support terse dumps in the packet scheduler, from Vlad Buslov. 27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei. 28) Add devm_register_netdev(), from Bartosz Golaszewski. 29) Minimize qdisc resets, from Cong Wang. 30) Get rid of kernel_getsockopt and kernel_setsockopt in order to eliminate set_fs/get_fs calls. From Christoph Hellwig. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits) selftests: net: ip_defrag: ignore EPERM net_failover: fixed rollback in net_failover_open() Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv" Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv" vmxnet3: allow rx flow hash ops only when rss is enabled hinic: add set_channels ethtool_ops support selftests/bpf: Add a default $(CXX) value tools/bpf: Don't use $(COMPILE.c) bpf, selftests: Use bpf_probe_read_kernel s390/bpf: Use bcr 0,%0 as tail call nop filler s390/bpf: Maintain 8-byte stack alignment selftests/bpf: Fix verifier test selftests/bpf: Fix sample_cnt shared between two threads bpf, selftests: Adapt cls_redirect to call csum_level helper bpf: Add csum_level helper for fixing up csum levels bpf: Fix up bpf_skb_adjust_room helper's skb csum setting sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf() crypto/chtls: IPv6 support for inline TLS Crypto/chcr: Fixes a coccinile check error Crypto/chcr: Fixes compilations warnings ...
2020-06-02mm: remove __vmalloc_node_flags_callerChristoph Hellwig1-1/+1
Just use __vmalloc_node instead which gets and extra argument. To be able to to use __vmalloc_node in all caller make it available outside of vmalloc and implement it in nommu.c. [akpm@linux-foundation.org: fix nommu build] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Gao Xiang <xiang@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Kelley <mikelley@microsoft.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Wei Liu <wei.liu@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: http://lkml.kernel.org/r/20200414131348.444715-25-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-27sysctl: pass kernel pointers to ->proc_handlerChristoph Hellwig1-6/+4
Instead of having all the sysctl handlers deal with user pointers, which is rather hairy in terms of the BPF interaction, copy the input to and from userspace in common code. This also means that the strings are always NUL-terminated by the common code, making the API a little bit safer. As most handler just pass through the data to one of the common handlers a lot of the changes are mechnical. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-12-01mm/mmap.c: rb_parent is not necessary in __vma_link_list()Wei Yang1-6/+2
Now we use rb_parent to get next, while this is not necessary. When prev is NULL, this means vma should be the first element in the list. Then next should be current first one (mm->mmap), no matter whether we have parent or not. After removing it, the code shows the beauty of symmetry. Link: http://lkml.kernel.org/r/20190813032656.16625-1-richardw.yang@linux.intel.com Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-01mm/mmap.c: extract __vma_unlink_list() as counterpart for __vma_link_list()Wei Yang1-0/+14
Just make the code a little easier to read. Link: http://lkml.kernel.org/r/20191006012636.31521-3-richardw.yang@linux.intel.com Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24arm64, mm: make randomization selected by generic topdown mmap layoutAlexandre Ghiti1-2/+9
This commits selects ARCH_HAS_ELF_RANDOMIZE when an arch uses the generic topdown mmap layout functions so that this security feature is on by default. Note that this commit also removes the possibility for arm64 to have elf randomization and no MMU: without MMU, the security added by randomization is worth nothing. Link: http://lkml.kernel.org/r/20190730055113.23635-6-alex@ghiti.fr Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: James Hogan <jhogan@kernel.org> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24arm64, mm: move generic mmap layout functions to mmAlexandre Ghiti1-1/+77
arm64 handles top-down mmap layout in a way that can be easily reused by other architectures, so make it available in mm. It then introduces a new config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT that can be set by other architectures to benefit from those functions. Note that this new config depends on MMU being enabled, if selected without MMU support, a warning will be thrown. Link: http://lkml.kernel.org/r/20190730055113.23635-5-alex@ghiti.fr Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Suggested-by: Christoph Hellwig <hch@infradead.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: James Hogan <jhogan@kernel.org> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm, fs: move randomize_stack_top from fs to mmAlexandre Ghiti1-0/+22
Patch series "Provide generic top-down mmap layout functions", v6. This series introduces generic functions to make top-down mmap layout easily accessible to architectures, in particular riscv which was the initial goal of this series. The generic implementation was taken from arm64 and used successively by arm, mips and finally riscv. Note that in addition the series fixes 2 issues: - stack randomization was taken into account even if not necessary. - [1] fixed an issue with mmap base which did not take into account randomization but did not report it to arm and mips, so by moving arm64 into a generic library, this problem is now fixed for both architectures. This work is an effort to factorize architecture functions to avoid code duplication and oversights as in [1]. [1]: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1429066.html This patch (of 14): This preparatory commit moves this function so that further introduction of generic topdown mmap layout is contained only in mm/util.c. Link: http://lkml.kernel.org/r/20190730055113.23635-2-alex@ghiti.fr Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: James Hogan <jhogan@kernel.org> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: move memcmp_pages() and pages_identical()Song Liu1-0/+13
Patch series "THP aware uprobe", v13. This patchset makes uprobe aware of THPs. Currently, when uprobe is attached to text on THP, the page is split by FOLL_SPLIT. As a result, uprobe eliminates the performance benefit of THP. This set makes uprobe THP-aware. Instead of FOLL_SPLIT, we introduces FOLL_SPLIT_PMD, which only split PMD for uprobe. After all uprobes within the THP are removed, the PTE-mapped pages are regrouped as huge PMD. This set (plus a few THP patches) is also available at https://github.com/liu-song-6/linux/tree/uprobe-thp This patch (of 6): Move memcmp_pages() to mm/util.c and pages_identical() to mm.h, so that we can use them in other files. Link: http://lkml.kernel.org/r/20190815164525.1848545-2-songliubraving@fb.com Signed-off-by: Song Liu <songliubraving@fb.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox <matthew.wilcox@oracle.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24mm: introduce compound_nr()Matthew Wilcox (Oracle)1-1/+1
Replace 1 << compound_order(page) with compound_nr(page). Minor improvements in readability. Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-16mm: add account_locked_vm utility functionDaniel Jordan1-0/+75
locked_vm accounting is done roughly the same way in five places, so unify them in a helper. Include the helper's caller in the debug print to distinguish between callsites. Error codes stay the same, so user-visible behavior does too. The one exception is that the -EPERM case in tce_account_locked_vm is removed because Alexey has never seen it triggered. [daniel.m.jordan@oracle.com: v3] Link: http://lkml.kernel.org/r/20190529205019.20927-1-daniel.m.jordan@oracle.com [sfr@canb.auug.org.au: fix mm/util.c] Link: http://lkml.kernel.org/r/20190524175045.26897-1-daniel.m.jordan@oracle.com Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Alex Williamson <alex.williamson@redhat.com> Cc: Alan Tull <atull@kernel.org> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christoph Lameter <cl@linux.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Moritz Fischer <mdf@kernel.org> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Steve Sistare <steven.sistare@oracle.com> Cc: Wu Hao <hao.wu@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-12mm: consolidate the get_user_pages* implementationsChristoph Hellwig1-47/+0
Always build mm/gup.c so that we don't have to provide separate nommu stubs. Also merge the get_user_pages_fast and __get_user_pages_fast stubs when HAVE_FAST_GUP into the main implementations, which will never call the fast path if HAVE_FAST_GUP is not set. This also ensures the new put_user_pages* helpers are available for nommu, as those are currently missing, which would create a problem as soon as we actually grew users for it. Link: http://lkml.kernel.org/r/20190625143715.1689-13-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-01prctl_set_mm: downgrade mmap_sem to read lockMichal Koutný1-2/+2
The commit a3b609ef9f8b ("proc read mm's {arg,env}_{start,end} with mmap semaphore taken.") added synchronization of reading argument/environment boundaries under mmap_sem. Later commit 88aa7cc688d4 ("mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct") avoided the coarse use of mmap_sem in similar situations. But there still remained two places that (mis)use mmap_sem. get_cmdline should also use arg_lock instead of mmap_sem when it reads the boundaries. The second place that should use arg_lock is in prctl_set_mm. By protecting the boundaries fields with the arg_lock, we can downgrade mmap_sem to reader lock (analogous to what we already do in prctl_set_mm_map). [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/20190502125203.24014-3-mkoutny@suse.com Fixes: 88aa7cc688d4 ("mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct") Signed-off-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Co-developed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-21treewide: Add SPDX license identifier for missed filesThomas Gleixner1-0/+1
Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14mm: fix false-positive OVERCOMMIT_GUESS failuresJohannes Weiner1-46/+5
With the default overcommit==guess we occasionally run into mmap rejections despite plenty of memory that would get dropped under pressure but just isn't accounted reclaimable. One example of this is dying cgroups pinned by some page cache. A previous case was auxiliary path name memory associated with dentries; we have since annotated those allocations to avoid overcommit failures (see d79f7aa496fc ("mm: treat indirectly reclaimable memory as free in overcommit logic")). But trying to classify all allocated memory reliably as reclaimable and unreclaimable is a bit of a fool's errand. There could be a myriad of dependencies that constantly change with kernel versions. It becomes even more questionable of an effort when considering how this estimate of available memory is used: it's not compared to the system-wide allocated virtual memory in any way. It's not even compared to the allocating process's address space. It's compared to the single allocation request at hand! So we have an elaborate left-hand side of the equation that tries to assess the exact breathing room the system has available down to a page - and then compare it to an isolated allocation request with no additional context. We could fail an allocation of N bytes, but for two allocations of N/2 bytes we'd do this elaborate dance twice in a row and then still let N bytes of virtual memory through. This doesn't make a whole lot of sense. Let's take a step back and look at the actual goal of the heuristic. From the documentation: Heuristic overcommit handling. Obvious overcommits of address space are refused. Used for a typical system. It ensures a seriously wild allocation fails while allowing overcommit to reduce swap usage. root is allowed to allocate slightly more memory in this mode. This is the default. If all we want to do is catch clearly bogus allocation requests irrespective of the general virtual memory situation, the physical memory counter-part doesn't need to be that complicated, either. When in GUESS mode, catch wild allocations by comparing their request size to total amount of ram and swap in the system. Link: http://lkml.kernel.org/r/20190412191418.26333-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14mm/gup: change GUP fast to use flags rather than a write 'bool'Ira Weiny1-4/+4
To facilitate additional options to get_user_pages_fast() change the singular write parameter to be gup_flags. This patch does not change any functionality. New functionality will follow in subsequent patches. Some of the get_user_pages_fast() call sites were unchanged because they already passed FOLL_WRITE or 0 for the write parameter. NOTE: It was suggested to change the ordering of the get_user_pages_fast() arguments to ensure that callers were converted. This breaks the current GUP call site convention of having the returned pages be the final parameter. So the suggestion was rejected. Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Mike Marshall <hubcap@omnibond.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-05mm/util.c: fix strndup_user() commentAndrew Morton1-1/+1
The kerneldoc misdescribes strndup_user()'s return value. Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Timur Tabi <timur@freescale.com> Cc: Mihai Caraman <mihai.caraman@freescale.com> Cc: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-05docs/core-api/mm: fix return value descriptions in mm/Mike Rapoport1-11/+26
Many kernel-doc comments in mm/ have the return value descriptions either misformatted or omitted at all which makes kernel-doc script unhappy: $ make V=1 htmldocs ... ./mm/util.c:36: info: Scanning doc for kstrdup ./mm/util.c:41: warning: No description found for return value of 'kstrdup' ./mm/util.c:57: info: Scanning doc for kstrdup_const ./mm/util.c:66: warning: No description found for return value of 'kstrdup_const' ./mm/util.c:75: info: Scanning doc for kstrndup ./mm/util.c:83: warning: No description found for return value of 'kstrndup' ... Fixing the formatting and adding the missing return value descriptions eliminates ~100 such warnings. Link: http://lkml.kernel.org/r/1549549644-4903-4-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-21mm: don't let userspace spam allocations warningsDaniel Vetter1-1/+1
memdump_user usually gets fed unchecked userspace input. Blasting a full backtrace into dmesg every time is a bit excessive - I'm not sure on the kernel rule in general, but at least in drm we're trying not to let unpriviledge userspace spam the logs freely. Definitely not entire warning backtraces. It also means more filtering for our CI, because our testsuite exercises these corner cases and so hits these a lot. Link: http://lkml.kernel.org/r/20190220204058.11676-1-daniel.vetter@ffwll.ch Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Roman Gushchin <guro@fb.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Stancek <jstancek@redhat.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Bartosz Golaszewski <brgl@bgdev.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-08mm: page_mapped: don't assume compound page is huge or THPJan Stancek1-1/+1
LTP proc01 testcase has been observed to rarely trigger crashes on arm64: page_mapped+0x78/0xb4 stable_page_flags+0x27c/0x338 kpageflags_read+0xfc/0x164 proc_reg_read+0x7c/0xb8 __vfs_read+0x58/0x178 vfs_read+0x90/0x14c SyS_read+0x60/0xc0 The issue is that page_mapped() assumes that if compound page is not huge, then it must be THP. But if this is 'normal' compound page (COMPOUND_PAGE_DTOR), then following loop can keep running (for HPAGE_PMD_NR iterations) until it tries to read from memory that isn't mapped and triggers a panic: for (i = 0; i < hpage_nr_pages(page); i++) { if (atomic_read(&page[i]._mapcount) >= 0) return true; } I could replicate this on x86 (v4.20-rc4-98-g60b548237fed) only with a custom kernel module [1] which: - allocates compound page (PAGEC) of order 1 - allocates 2 normal pages (COPY), which are initialized to 0xff (to satisfy _mapcount >= 0) - 2 PAGEC page structs are copied to address of first COPY page - second page of COPY is marked as not present - call to page_mapped(COPY) now triggers fault on access to 2nd COPY page at offset 0x30 (_mapcount) [1] https://github.com/jstancek/reproducers/blob/master/kernel/page_mapped_crash/repro.c Fix the loop to iterate for "1 << compound_order" pages. Kirrill said "IIRC, sound subsystem can producuce custom mapped compound pages". Link: http://lkml.kernel.org/r/c440d69879e34209feba21e12d236d06bc0a25db.1543577156.git.jstancek@redhat.com Fixes: e1534ae95004 ("mm: differentiate page_mapped() from page_mapcount() for compound pages") Signed-off-by: Jan Stancek <jstancek@redhat.com> Debugged-by: Laszlo Ersek <lersek@redhat.com> Suggested-by: "Kirill A. Shutemov" <kirill@shutemov.name> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28mm: convert totalram_pages and totalhigh_pages variables to atomicArun KS1-1/+1
totalram_pages and totalhigh_pages are made static inline function. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes better to remove the lock and convert variables to atomic, with preventing poteintial store-to-read tearing as a bonus. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Suggested-by: Michal Hocko <mhocko@suse.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-26kvfree(): fix misleading commentAndrey Ryabinin1-1/+1
vfree() might sleep if called not in interrupt context. So does kvfree() too. Fix misleading kvfree()'s comment about allowed context. Link: http://lkml.kernel.org/r/20180914130512.10394-1-aryabinin@virtuozzo.com Fixes: 04b8e946075d ("mm/util.c: improve kvfree() kerneldoc") Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-26mm: rename and change semantics of nr_indirectly_reclaimable_bytesVlastimil Babka1-2/+1
The vmstat counter NR_INDIRECTLY_RECLAIMABLE_BYTES was introduced by commit eb59254608bc ("mm: introduce NR_INDIRECTLY_RECLAIMABLE_BYTES") with the goal of accounting objects that can be reclaimed, but cannot be allocated via a SLAB_RECLAIM_ACCOUNT cache. This is now possible via kmalloc() with __GFP_RECLAIMABLE flag, and the dcache external names user is converted. The counter is however still useful for accounting direct page allocations (i.e. not slab) with a shrinker, such as the ION page pool. So keep it, and: - change granularity to pages to be more like other counters; sub-page allocations should be able to use kmalloc - rename the counter to NR_KERNEL_MISC_RECLAIMABLE - expose the counter again in vmstat as "nr_kernel_misc_reclaimable"; we can again remove the check for not printing "hidden" counters Link: http://lkml.kernel.org/r/20180731090649.16028-5-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Vijayanand Jitta <vjitta@codeaurora.org> Cc: Laura Abbott <labbott@redhat.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-16mm: move is_kernel_rodata() to asm-generic/sections.hBartosz Golaszewski1-7/+0
Export this routine so that we can use it later in devm_kstrdup_const() and devm_kfree(). Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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