From: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>,
David Hildenbrand <david@redhat.com>,
"Liam R . Howlett" <Liam.Howlett@oracle.com>,
Vlastimil Babka <vbabka@suse.cz>, Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Michal Hocko <mhocko@suse.com>,
Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Jann Horn <jannh@google.com>, Pedro Falcato <pfalcato@suse.de>,
Zi Yan <ziy@nvidia.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
Nico Pache <npache@redhat.com>,
Ryan Roberts <ryan.roberts@arm.com>, Dev Jain <dev.jain@arm.com>,
Barry Song <baohua@kernel.org>, Lance Yang <lance.yang@linux.dev>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-doc@vger.kernel.org, linux-mm@kvack.org,
linux-trace-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org, Andrei Vagin <avagin@gmail.com>
Subject: [PATCH v4 7/9] tools/testing/vma: add VMA sticky userland tests
Date: Tue, 18 Nov 2025 10:17:49 +0000 [thread overview]
Message-ID: <5e2c7244485867befd052f8afc8188be6a4be670.1763460113.git.lorenzo.stoakes@oracle.com> (raw)
In-Reply-To: <cover.1763460113.git.lorenzo.stoakes@oracle.com>
Modify existing merge new/existing userland VMA tests to assert that
sticky VMA flags behave as expected.
We do so by generating every possible permutation of VMAs being
manipulated being sticky/not sticky and asserting that VMA flags with this
property retain are retained upon merge.
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
tools/testing/vma/vma.c | 89 ++++++++++++++++++++++++++++++++++++-----
1 file changed, 79 insertions(+), 10 deletions(-)
diff --git a/tools/testing/vma/vma.c b/tools/testing/vma/vma.c
index fd37ce3b2628..be79ab2ea44b 100644
--- a/tools/testing/vma/vma.c
+++ b/tools/testing/vma/vma.c
@@ -48,6 +48,8 @@ static struct anon_vma dummy_anon_vma;
#define ASSERT_EQ(_val1, _val2) ASSERT_TRUE((_val1) == (_val2))
#define ASSERT_NE(_val1, _val2) ASSERT_TRUE((_val1) != (_val2))
+#define IS_SET(_val, _flags) ((_val & _flags) == _flags)
+
static struct task_struct __current;
struct task_struct *get_current(void)
@@ -442,7 +444,7 @@ static bool test_simple_shrink(void)
return true;
}
-static bool test_merge_new(void)
+static bool __test_merge_new(bool is_sticky, bool a_is_sticky, bool b_is_sticky, bool c_is_sticky)
{
vm_flags_t vm_flags = VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE;
struct mm_struct mm = {};
@@ -470,23 +472,32 @@ static bool test_merge_new(void)
struct vm_area_struct *vma, *vma_a, *vma_b, *vma_c, *vma_d;
bool merged;
+ if (is_sticky)
+ vm_flags |= VM_STICKY;
+
/*
* 0123456789abc
* AA B CC
*/
vma_a = alloc_and_link_vma(&mm, 0, 0x2000, 0, vm_flags);
ASSERT_NE(vma_a, NULL);
+ if (a_is_sticky)
+ vm_flags_set(vma_a, VM_STICKY);
/* We give each VMA a single avc so we can test anon_vma duplication. */
INIT_LIST_HEAD(&vma_a->anon_vma_chain);
list_add(&dummy_anon_vma_chain_a.same_vma, &vma_a->anon_vma_chain);
vma_b = alloc_and_link_vma(&mm, 0x3000, 0x4000, 3, vm_flags);
ASSERT_NE(vma_b, NULL);
+ if (b_is_sticky)
+ vm_flags_set(vma_b, VM_STICKY);
INIT_LIST_HEAD(&vma_b->anon_vma_chain);
list_add(&dummy_anon_vma_chain_b.same_vma, &vma_b->anon_vma_chain);
vma_c = alloc_and_link_vma(&mm, 0xb000, 0xc000, 0xb, vm_flags);
ASSERT_NE(vma_c, NULL);
+ if (c_is_sticky)
+ vm_flags_set(vma_c, VM_STICKY);
INIT_LIST_HEAD(&vma_c->anon_vma_chain);
list_add(&dummy_anon_vma_chain_c.same_vma, &vma_c->anon_vma_chain);
@@ -521,6 +532,8 @@ static bool test_merge_new(void)
ASSERT_EQ(vma->anon_vma, &dummy_anon_vma);
ASSERT_TRUE(vma_write_started(vma));
ASSERT_EQ(mm.map_count, 3);
+ if (is_sticky || a_is_sticky || b_is_sticky)
+ ASSERT_TRUE(IS_SET(vma->vm_flags, VM_STICKY));
/*
* Merge to PREVIOUS VMA.
@@ -538,6 +551,8 @@ static bool test_merge_new(void)
ASSERT_EQ(vma->anon_vma, &dummy_anon_vma);
ASSERT_TRUE(vma_write_started(vma));
ASSERT_EQ(mm.map_count, 3);
+ if (is_sticky || a_is_sticky)
+ ASSERT_TRUE(IS_SET(vma->vm_flags, VM_STICKY));
/*
* Merge to NEXT VMA.
@@ -557,6 +572,8 @@ static bool test_merge_new(void)
ASSERT_EQ(vma->anon_vma, &dummy_anon_vma);
ASSERT_TRUE(vma_write_started(vma));
ASSERT_EQ(mm.map_count, 3);
+ if (is_sticky) /* D uses is_sticky. */
+ ASSERT_TRUE(IS_SET(vma->vm_flags, VM_STICKY));
/*
* Merge BOTH sides.
@@ -575,6 +592,8 @@ static bool test_merge_new(void)
ASSERT_EQ(vma->anon_vma, &dummy_anon_vma);
ASSERT_TRUE(vma_write_started(vma));
ASSERT_EQ(mm.map_count, 2);
+ if (is_sticky || a_is_sticky)
+ ASSERT_TRUE(IS_SET(vma->vm_flags, VM_STICKY));
/*
* Merge to NEXT VMA.
@@ -593,6 +612,8 @@ static bool test_merge_new(void)
ASSERT_EQ(vma->anon_vma, &dummy_anon_vma);
ASSERT_TRUE(vma_write_started(vma));
ASSERT_EQ(mm.map_count, 2);
+ if (is_sticky || c_is_sticky)
+ ASSERT_TRUE(IS_SET(vma->vm_flags, VM_STICKY));
/*
* Merge BOTH sides.
@@ -610,6 +631,8 @@ static bool test_merge_new(void)
ASSERT_EQ(vma->anon_vma, &dummy_anon_vma);
ASSERT_TRUE(vma_write_started(vma));
ASSERT_EQ(mm.map_count, 1);
+ if (is_sticky || a_is_sticky || c_is_sticky)
+ ASSERT_TRUE(IS_SET(vma->vm_flags, VM_STICKY));
/*
* Final state.
@@ -638,6 +661,20 @@ static bool test_merge_new(void)
return true;
}
+static bool test_merge_new(void)
+{
+ int i, j, k, l;
+
+ /* Generate every possible permutation of sticky flags. */
+ for (i = 0; i < 2; i++)
+ for (j = 0; j < 2; j++)
+ for (k = 0; k < 2; k++)
+ for (l = 0; l < 2; l++)
+ ASSERT_TRUE(__test_merge_new(i, j, k, l));
+
+ return true;
+}
+
static bool test_vma_merge_special_flags(void)
{
vm_flags_t vm_flags = VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE;
@@ -974,9 +1011,11 @@ static bool test_vma_merge_new_with_close(void)
return true;
}
-static bool test_merge_existing(void)
+static bool __test_merge_existing(bool prev_is_sticky, bool middle_is_sticky, bool next_is_sticky)
{
vm_flags_t vm_flags = VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE;
+ vm_flags_t prev_flags = vm_flags;
+ vm_flags_t next_flags = vm_flags;
struct mm_struct mm = {};
VMA_ITERATOR(vmi, &mm, 0);
struct vm_area_struct *vma, *vma_prev, *vma_next;
@@ -989,6 +1028,13 @@ static bool test_merge_existing(void)
};
struct anon_vma_chain avc = {};
+ if (prev_is_sticky)
+ prev_flags |= VM_STICKY;
+ if (middle_is_sticky)
+ vm_flags |= VM_STICKY;
+ if (next_is_sticky)
+ next_flags |= VM_STICKY;
+
/*
* Merge right case - partial span.
*
@@ -1001,7 +1047,7 @@ static bool test_merge_existing(void)
*/
vma = alloc_and_link_vma(&mm, 0x2000, 0x6000, 2, vm_flags);
vma->vm_ops = &vm_ops; /* This should have no impact. */
- vma_next = alloc_and_link_vma(&mm, 0x6000, 0x9000, 6, vm_flags);
+ vma_next = alloc_and_link_vma(&mm, 0x6000, 0x9000, 6, next_flags);
vma_next->vm_ops = &vm_ops; /* This should have no impact. */
vmg_set_range_anon_vma(&vmg, 0x3000, 0x6000, 3, vm_flags, &dummy_anon_vma);
vmg.middle = vma;
@@ -1019,6 +1065,8 @@ static bool test_merge_existing(void)
ASSERT_TRUE(vma_write_started(vma));
ASSERT_TRUE(vma_write_started(vma_next));
ASSERT_EQ(mm.map_count, 2);
+ if (middle_is_sticky || next_is_sticky)
+ ASSERT_TRUE(IS_SET(vma_next->vm_flags, VM_STICKY));
/* Clear down and reset. */
ASSERT_EQ(cleanup_mm(&mm, &vmi), 2);
@@ -1034,7 +1082,7 @@ static bool test_merge_existing(void)
* NNNNNNN
*/
vma = alloc_and_link_vma(&mm, 0x2000, 0x6000, 2, vm_flags);
- vma_next = alloc_and_link_vma(&mm, 0x6000, 0x9000, 6, vm_flags);
+ vma_next = alloc_and_link_vma(&mm, 0x6000, 0x9000, 6, next_flags);
vma_next->vm_ops = &vm_ops; /* This should have no impact. */
vmg_set_range_anon_vma(&vmg, 0x2000, 0x6000, 2, vm_flags, &dummy_anon_vma);
vmg.middle = vma;
@@ -1047,6 +1095,8 @@ static bool test_merge_existing(void)
ASSERT_EQ(vma_next->anon_vma, &dummy_anon_vma);
ASSERT_TRUE(vma_write_started(vma_next));
ASSERT_EQ(mm.map_count, 1);
+ if (middle_is_sticky || next_is_sticky)
+ ASSERT_TRUE(IS_SET(vma_next->vm_flags, VM_STICKY));
/* Clear down and reset. We should have deleted vma. */
ASSERT_EQ(cleanup_mm(&mm, &vmi), 1);
@@ -1061,7 +1111,7 @@ static bool test_merge_existing(void)
* 0123456789
* PPPPPPV
*/
- vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, vm_flags);
+ vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, prev_flags);
vma_prev->vm_ops = &vm_ops; /* This should have no impact. */
vma = alloc_and_link_vma(&mm, 0x3000, 0x7000, 3, vm_flags);
vma->vm_ops = &vm_ops; /* This should have no impact. */
@@ -1081,6 +1131,8 @@ static bool test_merge_existing(void)
ASSERT_TRUE(vma_write_started(vma_prev));
ASSERT_TRUE(vma_write_started(vma));
ASSERT_EQ(mm.map_count, 2);
+ if (prev_is_sticky || middle_is_sticky)
+ ASSERT_TRUE(IS_SET(vma_prev->vm_flags, VM_STICKY));
/* Clear down and reset. */
ASSERT_EQ(cleanup_mm(&mm, &vmi), 2);
@@ -1095,7 +1147,7 @@ static bool test_merge_existing(void)
* 0123456789
* PPPPPPP
*/
- vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, vm_flags);
+ vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, prev_flags);
vma_prev->vm_ops = &vm_ops; /* This should have no impact. */
vma = alloc_and_link_vma(&mm, 0x3000, 0x7000, 3, vm_flags);
vmg_set_range_anon_vma(&vmg, 0x3000, 0x7000, 3, vm_flags, &dummy_anon_vma);
@@ -1110,6 +1162,8 @@ static bool test_merge_existing(void)
ASSERT_EQ(vma_prev->anon_vma, &dummy_anon_vma);
ASSERT_TRUE(vma_write_started(vma_prev));
ASSERT_EQ(mm.map_count, 1);
+ if (prev_is_sticky || middle_is_sticky)
+ ASSERT_TRUE(IS_SET(vma_prev->vm_flags, VM_STICKY));
/* Clear down and reset. We should have deleted vma. */
ASSERT_EQ(cleanup_mm(&mm, &vmi), 1);
@@ -1124,10 +1178,10 @@ static bool test_merge_existing(void)
* 0123456789
* PPPPPPPPPP
*/
- vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, vm_flags);
+ vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, prev_flags);
vma_prev->vm_ops = &vm_ops; /* This should have no impact. */
vma = alloc_and_link_vma(&mm, 0x3000, 0x7000, 3, vm_flags);
- vma_next = alloc_and_link_vma(&mm, 0x7000, 0x9000, 7, vm_flags);
+ vma_next = alloc_and_link_vma(&mm, 0x7000, 0x9000, 7, next_flags);
vmg_set_range_anon_vma(&vmg, 0x3000, 0x7000, 3, vm_flags, &dummy_anon_vma);
vmg.prev = vma_prev;
vmg.middle = vma;
@@ -1140,6 +1194,8 @@ static bool test_merge_existing(void)
ASSERT_EQ(vma_prev->anon_vma, &dummy_anon_vma);
ASSERT_TRUE(vma_write_started(vma_prev));
ASSERT_EQ(mm.map_count, 1);
+ if (prev_is_sticky || middle_is_sticky || next_is_sticky)
+ ASSERT_TRUE(IS_SET(vma_prev->vm_flags, VM_STICKY));
/* Clear down and reset. We should have deleted prev and next. */
ASSERT_EQ(cleanup_mm(&mm, &vmi), 1);
@@ -1159,9 +1215,9 @@ static bool test_merge_existing(void)
* PPPVVVVVNNN
*/
- vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, vm_flags);
+ vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, prev_flags);
vma = alloc_and_link_vma(&mm, 0x3000, 0x8000, 3, vm_flags);
- vma_next = alloc_and_link_vma(&mm, 0x8000, 0xa000, 8, vm_flags);
+ vma_next = alloc_and_link_vma(&mm, 0x8000, 0xa000, 8, next_flags);
vmg_set_range(&vmg, 0x4000, 0x5000, 4, vm_flags);
vmg.prev = vma;
@@ -1204,6 +1260,19 @@ static bool test_merge_existing(void)
return true;
}
+static bool test_merge_existing(void)
+{
+ int i, j, k;
+
+ /* Generate every possible permutation of sticky flags. */
+ for (i = 0; i < 2; i++)
+ for (j = 0; j < 2; j++)
+ for (k = 0; k < 2; k++)
+ ASSERT_TRUE(__test_merge_existing(i, j, k));
+
+ return true;
+}
+
static bool test_anon_vma_non_mergeable(void)
{
vm_flags_t vm_flags = VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE;
--
2.51.2
next prev parent reply other threads:[~2025-11-18 10:19 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-18 10:17 [PATCH v4 0/9] introduce VM_MAYBE_GUARD and make it sticky Lorenzo Stoakes
2025-11-18 10:17 ` [PATCH v4 1/9] mm: introduce VM_MAYBE_GUARD and make visible in /proc/$pid/smaps Lorenzo Stoakes
2025-11-20 5:48 ` Lance Yang
2025-11-18 10:17 ` [PATCH v4 2/9] mm: add atomic VMA flags and set VM_MAYBE_GUARD as such Lorenzo Stoakes
2025-11-19 9:06 ` David Hildenbrand (Red Hat)
2025-11-20 6:11 ` Lance Yang
2025-11-18 10:17 ` [PATCH v4 3/9] mm: update vma_modify_flags() to handle residual flags, document Lorenzo Stoakes
2025-11-19 16:27 ` Vlastimil Babka
2025-11-19 16:36 ` Pedro Falcato
2025-11-18 10:17 ` [PATCH v4 4/9] mm: implement sticky VMA flags Lorenzo Stoakes
2025-11-21 16:09 ` David Hildenbrand (Red Hat)
2025-11-18 10:17 ` [PATCH v4 5/9] mm: introduce copy-on-fork VMAs and make VM_MAYBE_GUARD one Lorenzo Stoakes
2025-11-19 9:17 ` David Hildenbrand (Red Hat)
2025-11-18 10:17 ` [PATCH v4 6/9] mm: set the VM_MAYBE_GUARD flag on guard region install Lorenzo Stoakes
2025-11-19 9:16 ` David Hildenbrand (Red Hat)
2025-11-19 9:27 ` Lorenzo Stoakes
2025-11-18 10:17 ` Lorenzo Stoakes [this message]
2025-11-18 10:17 ` [PATCH v4 8/9] tools/testing/selftests/mm: add MADV_COLLAPSE test case Lorenzo Stoakes
2025-11-18 10:17 ` [PATCH v4 9/9] tools/testing/selftests/mm: add smaps visibility guard region test Lorenzo Stoakes
2025-11-18 17:33 ` [PATCH v4 0/9] introduce VM_MAYBE_GUARD and make it sticky Andrew Morton
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