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authorLinus Torvalds <torvalds@linux-foundation.org>2024-06-27 03:51:39 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2024-06-27 03:51:39 +0300
commitafcd48134c58d6af45fb3fdb648f1260b20f2326 (patch)
treefe36b28e43f81c26e00355336e0bcbe7164790f5
parent24ca36a562d63f1bff04c3f11236f52969c67717 (diff)
parentab1ffc86cb5bec1c92387b9811d9036512f8f4eb (diff)
downloadlinux-afcd48134c58d6af45fb3fdb648f1260b20f2326.tar.xz
Merge tag 'mm-hotfixes-stable-2024-06-26-17-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton: "13 hotfixes, 7 are cc:stable. All are MM related apart from a MAINTAINERS update. There is no identifiable theme here - just singleton patches in various places" * tag 'mm-hotfixes-stable-2024-06-26-17-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/memory: don't require head page for do_set_pmd() mm/page_alloc: Separate THP PCP into movable and non-movable categories nfs: drop the incorrect assertion in nfs_swap_rw() mm/migrate: make migrate_pages_batch() stats consistent MAINTAINERS: TPM DEVICE DRIVER: update the W-tag selftests/mm:fix test_prctl_fork_exec return failure mm: convert page type macros to enum ocfs2: fix DIO failure due to insufficient transaction credits kasan: fix bad call to unpoison_slab_object mm: handle profiling for fake memory allocations during compaction mm/slab: fix 'variable obj_exts set but not used' warning /proc/pid/smaps: add mseal info for vma mm: fix incorrect vbq reference in purge_fragmented_block
-rw-r--r--Documentation/filesystems/proc.rst1
-rw-r--r--MAINTAINERS2
-rw-r--r--fs/nfs/direct.c2
-rw-r--r--fs/ocfs2/aops.c5
-rw-r--r--fs/ocfs2/journal.c17
-rw-r--r--fs/ocfs2/journal.h2
-rw-r--r--fs/ocfs2/ocfs2_trace.h2
-rw-r--r--fs/proc/task_mmu.c3
-rw-r--r--include/linux/mm.h5
-rw-r--r--include/linux/mmzone.h9
-rw-r--r--include/linux/page-flags.h21
-rw-r--r--mm/compaction.c11
-rw-r--r--mm/internal.h5
-rw-r--r--mm/kasan/common.c2
-rw-r--r--mm/memory.c3
-rw-r--r--mm/migrate.c5
-rw-r--r--mm/page_alloc.c9
-rw-r--r--mm/slub.c7
-rw-r--r--mm/vmalloc.c21
-rw-r--r--tools/testing/selftests/mm/ksm_functional_tests.c38
20 files changed, 117 insertions, 53 deletions
diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index 7c3a565ffbef..82d142de3461 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -571,6 +571,7 @@ encoded manner. The codes are the following:
um userfaultfd missing tracking
uw userfaultfd wr-protect tracking
ss shadow stack page
+ sl sealed
== =======================================
Note that there is no guarantee that every flag and associated mnemonic will
diff --git a/MAINTAINERS b/MAINTAINERS
index 2ca8f35dfe03..43353b705988 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22745,7 +22745,7 @@ M: Jarkko Sakkinen <jarkko@kernel.org>
R: Jason Gunthorpe <jgg@ziepe.ca>
L: linux-integrity@vger.kernel.org
S: Maintained
-W: https://gitlab.com/jarkkojs/linux-tpmdd-test
+W: https://codeberg.org/jarkko/linux-tpmdd-test
Q: https://patchwork.kernel.org/project/linux-integrity/list/
T: git git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git
F: Documentation/devicetree/bindings/tpm/
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index bb2f583eb28b..90079ca134dd 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -141,8 +141,6 @@ int nfs_swap_rw(struct kiocb *iocb, struct iov_iter *iter)
{
ssize_t ret;
- VM_BUG_ON(iov_iter_count(iter) != PAGE_SIZE);
-
if (iov_iter_rw(iter) == READ)
ret = nfs_file_direct_read(iocb, iter, true);
else
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index f0467d3b3c88..6be175a1ab3c 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -2366,6 +2366,11 @@ static int ocfs2_dio_end_io_write(struct inode *inode,
}
list_for_each_entry(ue, &dwc->dw_zero_list, ue_node) {
+ ret = ocfs2_assure_trans_credits(handle, credits);
+ if (ret < 0) {
+ mlog_errno(ret);
+ break;
+ }
ret = ocfs2_mark_extent_written(inode, &et, handle,
ue->ue_cpos, 1,
ue->ue_phys,
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index 86807086b2df..530fba34f6d3 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -446,6 +446,23 @@ bail:
}
/*
+ * Make sure handle has at least 'nblocks' credits available. If it does not
+ * have that many credits available, we will try to extend the handle to have
+ * enough credits. If that fails, we will restart transaction to have enough
+ * credits. Similar notes regarding data consistency and locking implications
+ * as for ocfs2_extend_trans() apply here.
+ */
+int ocfs2_assure_trans_credits(handle_t *handle, int nblocks)
+{
+ int old_nblks = jbd2_handle_buffer_credits(handle);
+
+ trace_ocfs2_assure_trans_credits(old_nblks);
+ if (old_nblks >= nblocks)
+ return 0;
+ return ocfs2_extend_trans(handle, nblocks - old_nblks);
+}
+
+/*
* If we have fewer than thresh credits, extend by OCFS2_MAX_TRANS_DATA.
* If that fails, restart the transaction & regain write access for the
* buffer head which is used for metadata modifications.
diff --git a/fs/ocfs2/journal.h b/fs/ocfs2/journal.h
index 41c9fe7e62f9..e3c3a35dc5e0 100644
--- a/fs/ocfs2/journal.h
+++ b/fs/ocfs2/journal.h
@@ -243,6 +243,8 @@ handle_t *ocfs2_start_trans(struct ocfs2_super *osb,
int ocfs2_commit_trans(struct ocfs2_super *osb,
handle_t *handle);
int ocfs2_extend_trans(handle_t *handle, int nblocks);
+int ocfs2_assure_trans_credits(handle_t *handle,
+ int nblocks);
int ocfs2_allocate_extend_trans(handle_t *handle,
int thresh);
diff --git a/fs/ocfs2/ocfs2_trace.h b/fs/ocfs2/ocfs2_trace.h
index 60e208b01c8d..0511c69c9fde 100644
--- a/fs/ocfs2/ocfs2_trace.h
+++ b/fs/ocfs2/ocfs2_trace.h
@@ -2577,6 +2577,8 @@ DEFINE_OCFS2_ULL_UINT_EVENT(ocfs2_commit_cache_end);
DEFINE_OCFS2_INT_INT_EVENT(ocfs2_extend_trans);
+DEFINE_OCFS2_INT_EVENT(ocfs2_assure_trans_credits);
+
DEFINE_OCFS2_INT_EVENT(ocfs2_extend_trans_restart);
DEFINE_OCFS2_INT_INT_EVENT(ocfs2_allocate_extend_trans);
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f8d35f993fe5..71e5039d940d 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -707,6 +707,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
#ifdef CONFIG_X86_USER_SHADOW_STACK
[ilog2(VM_SHADOW_STACK)] = "ss",
#endif
+#ifdef CONFIG_64BIT
+ [ilog2(VM_SEALED)] = "sl",
+#endif
};
size_t i;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9a5652c5fadd..eb7c96d24ac0 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -406,6 +406,11 @@ extern unsigned int kobjsize(const void *objp);
#define VM_ALLOW_ANY_UNCACHED VM_NONE
#endif
+#ifdef CONFIG_64BIT
+/* VM is sealed, in vm_flags */
+#define VM_SEALED _BITUL(63)
+#endif
+
/* Bits set in the VMA until the stack is in its final location */
#define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ | VM_STACK_EARLY)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 8f9c9590a42c..586a8f0104d7 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -654,13 +654,12 @@ enum zone_watermarks {
};
/*
- * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER. One additional list
- * for THP which will usually be GFP_MOVABLE. Even if it is another type,
- * it should not contribute to serious fragmentation causing THP allocation
- * failures.
+ * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER. Two additional lists
+ * are added for THP. One PCP list is used by GPF_MOVABLE, and the other PCP list
+ * is used by GFP_UNMOVABLE and GFP_RECLAIMABLE.
*/
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-#define NR_PCP_THP 1
+#define NR_PCP_THP 2
#else
#define NR_PCP_THP 0
#endif
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 104078afe0b1..b9e914e1face 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -944,15 +944,18 @@ PAGEFLAG_FALSE(HasHWPoisoned, has_hwpoisoned)
* mistaken for a page type value.
*/
-#define PAGE_TYPE_BASE 0xf0000000
-/* Reserve 0x0000007f to catch underflows of _mapcount */
-#define PAGE_MAPCOUNT_RESERVE -128
-#define PG_buddy 0x00000080
-#define PG_offline 0x00000100
-#define PG_table 0x00000200
-#define PG_guard 0x00000400
-#define PG_hugetlb 0x00000800
-#define PG_slab 0x00001000
+enum pagetype {
+ PG_buddy = 0x00000080,
+ PG_offline = 0x00000100,
+ PG_table = 0x00000200,
+ PG_guard = 0x00000400,
+ PG_hugetlb = 0x00000800,
+ PG_slab = 0x00001000,
+
+ PAGE_TYPE_BASE = 0xf0000000,
+ /* Reserve 0x0000007f to catch underflows of _mapcount */
+ PAGE_MAPCOUNT_RESERVE = -128,
+};
#define PageType(page, flag) \
((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
diff --git a/mm/compaction.c b/mm/compaction.c
index e731d45befc7..739b1bf3d637 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -79,6 +79,13 @@ static inline bool is_via_compact_memory(int order) { return false; }
#define COMPACTION_HPAGE_ORDER (PMD_SHIFT - PAGE_SHIFT)
#endif
+static struct page *mark_allocated_noprof(struct page *page, unsigned int order, gfp_t gfp_flags)
+{
+ post_alloc_hook(page, order, __GFP_MOVABLE);
+ return page;
+}
+#define mark_allocated(...) alloc_hooks(mark_allocated_noprof(__VA_ARGS__))
+
static void split_map_pages(struct list_head *freepages)
{
unsigned int i, order;
@@ -93,7 +100,7 @@ static void split_map_pages(struct list_head *freepages)
nr_pages = 1 << order;
- post_alloc_hook(page, order, __GFP_MOVABLE);
+ mark_allocated(page, order, __GFP_MOVABLE);
if (order)
split_page(page, order);
@@ -122,7 +129,7 @@ static unsigned long release_free_list(struct list_head *freepages)
* Convert free pages into post allocation pages, so
* that we can free them via __free_page.
*/
- post_alloc_hook(page, order, __GFP_MOVABLE);
+ mark_allocated(page, order, __GFP_MOVABLE);
__free_pages(page, order);
if (pfn > high_pfn)
high_pfn = pfn;
diff --git a/mm/internal.h b/mm/internal.h
index c72c306761a4..6902b7dd8509 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1435,11 +1435,6 @@ unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg,
int priority);
#ifdef CONFIG_64BIT
-/* VM is sealed, in vm_flags */
-#define VM_SEALED _BITUL(63)
-#endif
-
-#ifdef CONFIG_64BIT
static inline int can_do_mseal(unsigned long flags)
{
if (flags)
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index e7c9a4dc89f8..85e7c6b4575c 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -532,7 +532,7 @@ void __kasan_mempool_unpoison_object(void *ptr, size_t size, unsigned long ip)
return;
/* Unpoison the object and save alloc info for non-kmalloc() allocations. */
- unpoison_slab_object(slab->slab_cache, ptr, size, flags);
+ unpoison_slab_object(slab->slab_cache, ptr, flags, false);
/* Poison the redzone and save alloc info for kmalloc() allocations. */
if (is_kmalloc_cache(slab->slab_cache))
diff --git a/mm/memory.c b/mm/memory.c
index 25a77c4fe4a0..d10e616d7389 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4608,8 +4608,9 @@ vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
if (!thp_vma_suitable_order(vma, haddr, PMD_ORDER))
return ret;
- if (page != &folio->page || folio_order(folio) != HPAGE_PMD_ORDER)
+ if (folio_order(folio) != HPAGE_PMD_ORDER)
return ret;
+ page = &folio->page;
/*
* Just backoff if any subpage of a THP is corrupted otherwise
diff --git a/mm/migrate.c b/mm/migrate.c
index 2cc5a68f6843..20cb9f5f7446 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1659,6 +1659,10 @@ static int migrate_pages_batch(struct list_head *from,
* migrate_pages() may report success with (split but
* unmigrated) pages still on its fromlist; whereas it
* always reports success when its fromlist is empty.
+ * stats->nr_thp_failed should be increased too,
+ * otherwise stats inconsistency will happen when
+ * migrate_pages_batch is called via migrate_pages()
+ * with MIGRATE_SYNC and MIGRATE_ASYNC.
*
* Only check it without removing it from the list.
* Since the folio can be on deferred_split_scan()
@@ -1675,6 +1679,7 @@ static int migrate_pages_batch(struct list_head *from,
!list_empty(&folio->_deferred_list)) {
if (try_split_folio(folio, split_folios) == 0) {
nr_failed++;
+ stats->nr_thp_failed += is_thp;
stats->nr_thp_split += is_thp;
stats->nr_split++;
continue;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 7300aa9f14b0..9ecf99190ea2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -504,10 +504,15 @@ out:
static inline unsigned int order_to_pindex(int migratetype, int order)
{
+ bool __maybe_unused movable;
+
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
if (order > PAGE_ALLOC_COSTLY_ORDER) {
VM_BUG_ON(order != HPAGE_PMD_ORDER);
- return NR_LOWORDER_PCP_LISTS;
+
+ movable = migratetype == MIGRATE_MOVABLE;
+
+ return NR_LOWORDER_PCP_LISTS + movable;
}
#else
VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);
@@ -521,7 +526,7 @@ static inline int pindex_to_order(unsigned int pindex)
int order = pindex / MIGRATE_PCPTYPES;
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- if (pindex == NR_LOWORDER_PCP_LISTS)
+ if (pindex >= NR_LOWORDER_PCP_LISTS)
order = HPAGE_PMD_ORDER;
#else
VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER);
diff --git a/mm/slub.c b/mm/slub.c
index 1373ac365a46..4927edec6a8c 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3902,7 +3902,6 @@ bool slab_post_alloc_hook(struct kmem_cache *s, struct list_lru *lru,
unsigned int orig_size)
{
unsigned int zero_size = s->object_size;
- struct slabobj_ext *obj_exts;
bool kasan_init = init;
size_t i;
gfp_t init_flags = flags & gfp_allowed_mask;
@@ -3945,9 +3944,11 @@ bool slab_post_alloc_hook(struct kmem_cache *s, struct list_lru *lru,
kmemleak_alloc_recursive(p[i], s->object_size, 1,
s->flags, init_flags);
kmsan_slab_alloc(s, p[i], init_flags);
+#ifdef CONFIG_MEM_ALLOC_PROFILING
if (need_slab_obj_ext()) {
+ struct slabobj_ext *obj_exts;
+
obj_exts = prepare_slab_obj_exts_hook(s, flags, p[i]);
-#ifdef CONFIG_MEM_ALLOC_PROFILING
/*
* Currently obj_exts is used only for allocation profiling.
* If other users appear then mem_alloc_profiling_enabled()
@@ -3955,8 +3956,8 @@ bool slab_post_alloc_hook(struct kmem_cache *s, struct list_lru *lru,
*/
if (likely(obj_exts))
alloc_tag_add(&obj_exts->ref, current->alloc_tag, s->size);
-#endif
}
+#endif
}
return memcg_slab_post_alloc_hook(s, lru, flags, size, p);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 45e1506d58c3..d0cbdd7c1e5b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2498,6 +2498,7 @@ struct vmap_block {
struct list_head free_list;
struct rcu_head rcu_head;
struct list_head purge;
+ unsigned int cpu;
};
/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
@@ -2625,8 +2626,15 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
free_vmap_area(va);
return ERR_PTR(err);
}
-
- vbq = raw_cpu_ptr(&vmap_block_queue);
+ /*
+ * list_add_tail_rcu could happened in another core
+ * rather than vb->cpu due to task migration, which
+ * is safe as list_add_tail_rcu will ensure the list's
+ * integrity together with list_for_each_rcu from read
+ * side.
+ */
+ vb->cpu = raw_smp_processor_id();
+ vbq = per_cpu_ptr(&vmap_block_queue, vb->cpu);
spin_lock(&vbq->lock);
list_add_tail_rcu(&vb->free_list, &vbq->free);
spin_unlock(&vbq->lock);
@@ -2654,9 +2662,10 @@ static void free_vmap_block(struct vmap_block *vb)
}
static bool purge_fragmented_block(struct vmap_block *vb,
- struct vmap_block_queue *vbq, struct list_head *purge_list,
- bool force_purge)
+ struct list_head *purge_list, bool force_purge)
{
+ struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, vb->cpu);
+
if (vb->free + vb->dirty != VMAP_BBMAP_BITS ||
vb->dirty == VMAP_BBMAP_BITS)
return false;
@@ -2704,7 +2713,7 @@ static void purge_fragmented_blocks(int cpu)
continue;
spin_lock(&vb->lock);
- purge_fragmented_block(vb, vbq, &purge, true);
+ purge_fragmented_block(vb, &purge, true);
spin_unlock(&vb->lock);
}
rcu_read_unlock();
@@ -2841,7 +2850,7 @@ static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
* not purgeable, check whether there is dirty
* space to be flushed.
*/
- if (!purge_fragmented_block(vb, vbq, &purge_list, false) &&
+ if (!purge_fragmented_block(vb, &purge_list, false) &&
vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) {
unsigned long va_start = vb->va->va_start;
unsigned long s, e;
diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c
index 37de82da9be7..b61803e36d1c 100644
--- a/tools/testing/selftests/mm/ksm_functional_tests.c
+++ b/tools/testing/selftests/mm/ksm_functional_tests.c
@@ -656,12 +656,33 @@ unmap:
munmap(map, size);
}
+static void init_global_file_handles(void)
+{
+ mem_fd = open("/proc/self/mem", O_RDWR);
+ if (mem_fd < 0)
+ ksft_exit_fail_msg("opening /proc/self/mem failed\n");
+ ksm_fd = open("/sys/kernel/mm/ksm/run", O_RDWR);
+ if (ksm_fd < 0)
+ ksft_exit_skip("open(\"/sys/kernel/mm/ksm/run\") failed\n");
+ ksm_full_scans_fd = open("/sys/kernel/mm/ksm/full_scans", O_RDONLY);
+ if (ksm_full_scans_fd < 0)
+ ksft_exit_skip("open(\"/sys/kernel/mm/ksm/full_scans\") failed\n");
+ pagemap_fd = open("/proc/self/pagemap", O_RDONLY);
+ if (pagemap_fd < 0)
+ ksft_exit_skip("open(\"/proc/self/pagemap\") failed\n");
+ proc_self_ksm_stat_fd = open("/proc/self/ksm_stat", O_RDONLY);
+ proc_self_ksm_merging_pages_fd = open("/proc/self/ksm_merging_pages",
+ O_RDONLY);
+ ksm_use_zero_pages_fd = open("/sys/kernel/mm/ksm/use_zero_pages", O_RDWR);
+}
+
int main(int argc, char **argv)
{
unsigned int tests = 8;
int err;
if (argc > 1 && !strcmp(argv[1], FORK_EXEC_CHILD_PRG_NAME)) {
+ init_global_file_handles();
exit(test_child_ksm());
}
@@ -674,22 +695,7 @@ int main(int argc, char **argv)
pagesize = getpagesize();
- mem_fd = open("/proc/self/mem", O_RDWR);
- if (mem_fd < 0)
- ksft_exit_fail_msg("opening /proc/self/mem failed\n");
- ksm_fd = open("/sys/kernel/mm/ksm/run", O_RDWR);
- if (ksm_fd < 0)
- ksft_exit_skip("open(\"/sys/kernel/mm/ksm/run\") failed\n");
- ksm_full_scans_fd = open("/sys/kernel/mm/ksm/full_scans", O_RDONLY);
- if (ksm_full_scans_fd < 0)
- ksft_exit_skip("open(\"/sys/kernel/mm/ksm/full_scans\") failed\n");
- pagemap_fd = open("/proc/self/pagemap", O_RDONLY);
- if (pagemap_fd < 0)
- ksft_exit_skip("open(\"/proc/self/pagemap\") failed\n");
- proc_self_ksm_stat_fd = open("/proc/self/ksm_stat", O_RDONLY);
- proc_self_ksm_merging_pages_fd = open("/proc/self/ksm_merging_pages",
- O_RDONLY);
- ksm_use_zero_pages_fd = open("/sys/kernel/mm/ksm/use_zero_pages", O_RDWR);
+ init_global_file_handles();
test_unmerge();
test_unmerge_zero_pages();