linux/mm
Kirill A. Shutemov aff5e59840 mm: fix regression in remap_file_pages() emulation
[ Upstream commit 48f7df3294 ]

Grazvydas Ignotas has reported a regression in remap_file_pages()
emulation.

Testcase:
	#define _GNU_SOURCE
	#include <assert.h>
	#include <stdlib.h>
	#include <stdio.h>
	#include <sys/mman.h>

	#define SIZE    (4096 * 3)

	int main(int argc, char **argv)
	{
		unsigned long *p;
		long i;

		p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE,
				MAP_SHARED | MAP_ANONYMOUS, -1, 0);
		if (p == MAP_FAILED) {
			perror("mmap");
			return -1;
		}

		for (i = 0; i < SIZE / 4096; i++)
			p[i * 4096 / sizeof(*p)] = i;

		if (remap_file_pages(p, 4096, 0, 1, 0)) {
			perror("remap_file_pages");
			return -1;
		}

		if (remap_file_pages(p, 4096 * 2, 0, 1, 0)) {
			perror("remap_file_pages");
			return -1;
		}

		assert(p[0] == 1);

		munmap(p, SIZE);

		return 0;
	}

The second remap_file_pages() fails with -EINVAL.

The reason is that remap_file_pages() emulation assumes that the target
vma covers whole area we want to over map.  That assumption is broken by
first remap_file_pages() call: it split the area into two vma.

The solution is to check next adjacent vmas, if they map the same file
with the same flags.

Fixes: c8d78c1823 ("mm: replace remap_file_pages() syscall with emulation")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Grazvydas Ignotas <notasas@gmail.com>
Tested-by: Grazvydas Ignotas <notasas@gmail.com>
Cc: <stable@vger.kernel.org>	[4.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
History 2016-03-04 10:25:45 -05:00
..
kasan mm/mempool.c: kasan: poison mempool elements 2015-04-15 16:35:20 -07:00
backing-dev.c block: discard bdi_unregister() in favour of bdi_destroy() 2015-05-28 10:12:42 -06:00
balloon_compaction.c virtio_balloon: fix race between migration and ballooning 2016-02-03 15:31:09 -05:00
bootmem.c mem-hotplug: reset node managed pages when hot-adding a new pgdat 2014-11-13 16:17:06 -08:00
cleancache.c cleancache: remove limit on the number of cleancache enabled filesystems 2015-04-14 16:49:03 -07:00
cma.c mm: cma: add trace events for CMA allocations and freeings 2015-04-15 16:35:19 -07:00
cma.h mm: cma: allocation trigger 2015-04-14 16:49:00 -07:00
cma_debug.c mm/cma_debug.c: remove blank lines before DEFINE_SIMPLE_ATTRIBUTE() 2015-04-15 16:35:20 -07:00
compaction.c mm/compaction.c: fix "suitable_migration_target() unused" warning 2015-04-15 16:35:20 -07:00
debug-pagealloc.c mm/debug-pagealloc: make debug-pagealloc boottime configurable 2014-12-13 12:42:48 -08:00
debug.c mm: account pmd page tables to the process 2015-02-11 17:06:04 -08:00
dmapool.c mm/dmapool.c: fixed a brace coding style issue 2014-10-09 22:26:00 -04:00
early_ioremap.c mm: create generic early_ioremap() support 2014-04-07 16:36:15 -07:00
fadvise.c vfs: remove get_xip_mem 2015-02-16 17:56:03 -08:00
failslab.c switch debugfs to umode_t 2012-01-03 22:54:56 -05:00
filemap.c mm: make sendfile(2) killable 2015-11-09 14:33:34 -08:00
frontswap.c mm/frontswap.c: fix the condition in BUG_ON 2014-12-10 17:41:08 -08:00
gup.c mm: use READ_ONCE() for non-scalar types 2015-04-15 16:35:18 -07:00
highmem.c mm/highmem: make kmap cache coloring aware 2014-08-06 18:01:22 -07:00
huge_memory.c thp: use is_zero_pfn() only after pte_present() check 2015-11-09 14:33:39 -08:00
hugetlb.c mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a fault 2015-10-22 14:43:15 -07:00
hugetlb_cgroup.c mm: page_counter: pull "-1" handling out of page_counter_memparse() 2015-02-11 17:06:02 -08:00
hwpoison-inject.c mm/hwpoison-inject: check PageLRU of hpage 2015-05-05 17:10:11 -07:00
init-mm.c atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
internal.h mm: remove rest of ACCESS_ONCE() usages 2015-04-15 16:35:18 -07:00
interval_tree.c mm: replace vma->sharead.linear with vma->shared 2015-02-10 14:30:31 -08:00
Kconfig mm: cma: debugfs interface 2015-04-14 16:49:00 -07:00
Kconfig.debug mm/debug_pagealloc: remove obsolete Kconfig options 2015-01-08 15:10:52 -08:00
kmemcheck.c mm/slab_common: move kmem_cache definition to internal header 2014-10-09 22:25:50 -04:00
kmemleak-test.c mm/kmemleak-test.c: use pr_fmt for logging 2014-06-06 16:08:18 -07:00
kmemleak.c mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc() 2015-07-21 10:10:03 -07:00
ksm.c mm: remove rest of ACCESS_ONCE() usages 2015-04-15 16:35:18 -07:00
list_lru.c memcg: reparent list_lrus and free kmemcg_id on css offline 2015-02-12 18:54:10 -08:00
maccess.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
madvise.c vfs: remove get_xip_mem 2015-02-16 17:56:03 -08:00
Makefile mm: move memtest under mm 2015-04-14 16:49:06 -07:00
memblock.c mm/memblock.c: add debug output for memblock_add() 2015-04-15 16:35:19 -07:00
memcontrol.c memcg: only free spare array when readers are done 2016-02-03 16:23:17 -05:00
memory-failure.c mm: soft-offline: check return value in second __get_any_page() call 2016-02-03 16:23:17 -05:00
memory.c mm: avoid setting up anonymous pages into file mapping 2015-08-03 09:29:19 -07:00
memory_hotplug.c mm/memory_hotplug.c: set zone->wait_table to null after freeing it 2015-06-10 16:43:43 -07:00
mempolicy.c mm, thp: respect MPOL_PREFERRED policy with non-local node 2015-07-21 10:10:04 -07:00
mempool.c mm/mempool.c: kasan: poison mempool elements 2015-04-15 16:35:20 -07:00
memtest.c memtest: use phys_addr_t for physical addresses 2015-04-14 16:49:06 -07:00
migrate.c mm: migrate: hugetlb: putback destination hugepage to active list 2015-10-22 14:43:15 -07:00
mincore.c mincore: apply page table walker on do_mincore() 2015-02-11 17:06:06 -08:00
mlock.c mm: fix mlock accouting 2016-02-15 15:45:19 -05:00
mm_init.c mm/mm_init.c: mark mminit_loglevel __meminitdata 2015-02-12 18:54:11 -08:00
mmap.c mm: fix regression in remap_file_pages() emulation 2016-03-04 10:25:45 -05:00
mmu_context.c sched/mm: call finish_arch_post_lock_switch in idle_task_exit and use_mm 2014-02-21 08:50:17 +01:00
mmu_notifier.c mmu_notifier: add the callback for mmu_notifier_invalidate_range() 2014-11-13 13:46:09 +11:00
mmzone.c mm: microoptimize zonelist operations 2015-02-11 17:06:02 -08:00
mprotect.c mm: numa: preserve PTE write permissions across a NUMA hinting fault 2015-03-25 16:20:31 -07:00
mremap.c mm/mremap.c: clean up goto just return ERR_PTR 2015-04-15 16:35:18 -07:00
msync.c mm: remove rest usage of VM_NONLINEAR and pte_file() 2015-02-10 14:30:31 -08:00
nobootmem.c mem-hotplug: reset node managed pages when hot-adding a new pgdat 2014-11-13 16:17:06 -08:00
nommu.c nommu: use __vfs_read() 2015-04-11 22:27:56 -04:00
oom_kill.c mm/oom_kill.c: fix typo in comment 2015-04-15 16:35:16 -07:00
page-writeback.c writeback: use |1 instead of +1 to protect against div by zero 2015-04-23 10:36:33 -06:00
page_alloc.c mm: make page pfmemalloc check more robust 2015-09-29 19:26:06 +02:00
page_counter.c mm: page_counter: pull "-1" handling out of page_counter_memparse() 2015-02-11 17:06:02 -08:00
page_ext.c mm/page_owner: keep track of page owners 2014-12-13 12:42:48 -08:00
page_io.c direct_IO: remove rw from a_ops->direct_IO() 2015-04-11 22:29:45 -04:00
page_isolation.c CMA: page_isolation: check buddy before accessing it 2015-05-14 17:55:51 -07:00
page_owner.c mm/page_owner.c: remove unnecessary stack_trace field 2015-02-11 17:06:07 -08:00
pagewalk.c mm/pagewalk.c: prevent positive return value of walk_page_test() from being passed to callers 2015-03-25 16:20:30 -07:00
percpu-km.c percpu: implmeent pcpu_nr_empty_pop_pages and chunk->nr_populated 2014-09-02 14:46:05 -04:00
percpu-vm.c percpu: move region iterations out of pcpu_[de]populate_chunk() 2014-09-02 14:46:02 -04:00
percpu.c mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc() 2015-07-21 10:10:03 -07:00
pgtable-generic.c mm: convert p[te|md]_mknonnuma and remaining page table manipulations 2015-02-12 18:54:08 -08:00
process_vm_access.c process_vm_access: switch to {compat_,}import_iovec() 2015-04-11 22:27:12 -04:00
quicklist.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
readahead.c fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info 2015-01-20 14:03:04 -07:00
rmap.c mm: remove rest of ACCESS_ONCE() usages 2015-04-15 16:35:18 -07:00
shmem.c mm: shmem_zero_setup skip security check and lockdep conflict with XFS 2015-06-17 20:40:19 -10:00
slab.c mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1) 2015-10-22 14:43:27 -07:00
slab.h slub: make dead caches discard free slabs immediately 2015-02-12 18:54:10 -08:00
slab_common.c mm: slub: add kernel address sanitizer support for slub allocator 2015-02-13 21:21:41 -08:00
slob.c slob: make slob_alloc_node() static and remove EXPORT_SYMBOL() 2015-04-14 16:48:59 -07:00
slub.c mm: make page pfmemalloc check more robust 2015-09-29 19:26:06 +02:00
sparse-vmemmap.c mm/sparse: use memblock apis for early memory allocations 2014-01-21 16:19:47 -08:00
sparse.c mm: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:35:54 -07:00
swap.c mm: don't call __page_cache_release for hugetlb 2015-04-15 16:35:19 -07:00
swap_cgroup.c mm: page_cgroup: rename file to mm/swap_cgroup.c 2014-12-10 17:41:09 -08:00
swap_state.c mm: remove rest of ACCESS_ONCE() usages 2015-04-15 16:35:18 -07:00
swapfile.c mm: remove rest of ACCESS_ONCE() usages 2015-04-15 16:35:18 -07:00
truncate.c mm: rename deactivate_page to deactivate_file_page 2015-04-15 16:35:17 -07:00
util.c mm: uninline and cleanup page-mapping related helpers 2015-04-15 16:35:19 -07:00
vmacache.c mm,vmacache: count number of system-wide flushes 2014-12-13 12:42:48 -08:00
vmalloc.c mm/vmalloc: get rid of dirty bitmap inside vmap_block structure 2015-04-15 16:35:18 -07:00
vmpressure.c mm/vmpressure.c: fix race in vmpressure_work_fn() 2014-12-02 17:32:07 -08:00
vmscan.c vmscan: fix increasing nr_isolated incurred by putback unevictable pages 2015-09-29 19:26:12 +02:00
vmstat.c vmstat: Reduce time interval to stat update on idle cpu 2015-02-11 17:06:07 -08:00
workingset.c list_lru: add helpers to isolate items 2015-02-12 18:54:10 -08:00
zbud.c mm/zpool: add name argument to create zpool 2015-02-12 18:54:12 -08:00
zpool.c mm/zpool: add name argument to create zpool 2015-02-12 18:54:12 -08:00
zsmalloc.c zsmalloc: fix migrate_zspage-zs_free race condition 2016-02-03 16:23:21 -05:00
zswap.c mm/zpool: add name argument to create zpool 2015-02-12 18:54:12 -08:00