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Message-ID: <20250702084717.21360-1-lorenzo.stoakes@oracle.com>
Date: Wed, 2 Jul 2025 09:47:17 +0100
From: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: "Liam R . Howlett" <Liam.Howlett@...cle.com>,
Vlastimil Babka <vbabka@...e.cz>, Jann Horn <jannh@...gle.com>,
Pedro Falcato <pfalcato@...e.de>, linux-mm@...ck.org,
linux-kselftest@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] tools/testing/selftests: add mremap() unfaulted/faulted test cases
Assert that mremap() behaviour is as expected when moving around unfaulted
VMAs immediately adjacent to faulted ones, as well as moving around faulted
VMAs and placing them back immediately adjacent to the VMA from which they
were moved.
This also introduces a shared helper for the syscall version of mremap() so
we don't encounter any issues with libc filtering parameters.
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
---
tools/testing/selftests/mm/merge.c | 599 ++++++++++++++++++++++++++-
tools/testing/selftests/mm/vm_util.c | 8 +
tools/testing/selftests/mm/vm_util.h | 3 +
3 files changed, 608 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/mm/merge.c b/tools/testing/selftests/mm/merge.c
index 150dd5baed2b..cc4253f47f10 100644
--- a/tools/testing/selftests/mm/merge.c
+++ b/tools/testing/selftests/mm/merge.c
@@ -13,6 +13,7 @@
#include <sys/wait.h>
#include <linux/perf_event.h>
#include "vm_util.h"
+#include <linux/mman.h>
FIXTURE(merge)
{
@@ -25,7 +26,7 @@ FIXTURE_SETUP(merge)
{
self->page_size = psize();
/* Carve out PROT_NONE region to map over. */
- self->carveout = mmap(NULL, 12 * self->page_size, PROT_NONE,
+ self->carveout = mmap(NULL, 30 * self->page_size, PROT_NONE,
MAP_ANON | MAP_PRIVATE, -1, 0);
ASSERT_NE(self->carveout, MAP_FAILED);
/* Setup PROCMAP_QUERY interface. */
@@ -34,7 +35,7 @@ FIXTURE_SETUP(merge)
FIXTURE_TEARDOWN(merge)
{
- ASSERT_EQ(munmap(self->carveout, 12 * self->page_size), 0);
+ ASSERT_EQ(munmap(self->carveout, 30 * self->page_size), 0);
ASSERT_EQ(close_procmap(&self->procmap), 0);
/*
* Clear unconditionally, as some tests set this. It is no issue if this
@@ -576,4 +577,598 @@ TEST_F(merge, ksm_merge)
ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 2 * page_size);
}
+TEST_F(merge, mremap_unfaulted_to_faulted)
+{
+ unsigned int page_size = self->page_size;
+ char *carveout = self->carveout;
+ struct procmap_fd *procmap = &self->procmap;
+ char *ptr, *ptr2;
+
+ /*
+ * Map two distinct areas:
+ *
+ * |-----------| |-----------|
+ * | unfaulted | | unfaulted |
+ * |-----------| |-----------|
+ * ptr ptr2
+ */
+ ptr = mmap(&carveout[page_size], 5 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr, MAP_FAILED);
+ ptr2 = mmap(&carveout[7 * page_size], 5 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ /* Offset ptr2 further away. */
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, ptr2 + page_size * 1000);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ /*
+ * Fault in ptr:
+ * \
+ * |-----------| / |-----------|
+ * | faulted | \ | unfaulted |
+ * |-----------| / |-----------|
+ * ptr \ ptr2
+ */
+ ptr[0] = 'x';
+
+ /*
+ * Now move ptr2 adjacent to ptr:
+ *
+ * |-----------|-----------|
+ * | faulted | unfaulted |
+ * |-----------|-----------|
+ * ptr ptr2
+ *
+ * It should merge:
+ *
+ * |----------------------|
+ * | faulted |
+ * |----------------------|
+ * ptr
+ */
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &ptr[5 * page_size]);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ ASSERT_TRUE(find_vma_procmap(procmap, ptr));
+ ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr);
+ ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 10 * page_size);
+}
+
+TEST_F(merge, mremap_unfaulted_behind_faulted)
+{
+ unsigned int page_size = self->page_size;
+ char *carveout = self->carveout;
+ struct procmap_fd *procmap = &self->procmap;
+ char *ptr, *ptr2;
+
+ /*
+ * Map two distinct areas:
+ *
+ * |-----------| |-----------|
+ * | unfaulted | | unfaulted |
+ * |-----------| |-----------|
+ * ptr ptr2
+ */
+ ptr = mmap(&carveout[6 * page_size], 5 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr, MAP_FAILED);
+ ptr2 = mmap(&carveout[14 * page_size], 5 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ /* Offset ptr2 further away. */
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, ptr2 + page_size * 1000);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ /*
+ * Fault in ptr:
+ * \
+ * |-----------| / |-----------|
+ * | faulted | \ | unfaulted |
+ * |-----------| / |-----------|
+ * ptr \ ptr2
+ */
+ ptr[0] = 'x';
+
+ /*
+ * Now move ptr2 adjacent, but behind, ptr:
+ *
+ * |-----------|-----------|
+ * | unfaulted | faulted |
+ * |-----------|-----------|
+ * ptr2 ptr
+ *
+ * It should merge:
+ *
+ * |----------------------|
+ * | faulted |
+ * |----------------------|
+ * ptr2
+ */
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &carveout[page_size]);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ ASSERT_TRUE(find_vma_procmap(procmap, ptr2));
+ ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr2);
+ ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr2 + 10 * page_size);
+}
+
+TEST_F(merge, mremap_unfaulted_between_faulted)
+{
+ unsigned int page_size = self->page_size;
+ char *carveout = self->carveout;
+ struct procmap_fd *procmap = &self->procmap;
+ char *ptr, *ptr2, *ptr3;
+
+ /*
+ * Map three distinct areas:
+ *
+ * |-----------| |-----------| |-----------|
+ * | unfaulted | | unfaulted | | unfaulted |
+ * |-----------| |-----------| |-----------|
+ * ptr ptr2 ptr3
+ */
+ ptr = mmap(&carveout[page_size], 5 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr, MAP_FAILED);
+ ptr2 = mmap(&carveout[7 * page_size], 5 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr2, MAP_FAILED);
+ ptr3 = mmap(&carveout[14 * page_size], 5 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr3, MAP_FAILED);
+
+ /* Offset ptr3 further away. */
+ ptr3 = sys_mremap(ptr3, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, ptr3 + page_size * 2000);
+ ASSERT_NE(ptr3, MAP_FAILED);
+
+ /* Offset ptr2 further away. */
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, ptr2 + page_size * 1000);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ /*
+ * Fault in ptr, ptr3:
+ * \ \
+ * |-----------| / |-----------| / |-----------|
+ * | faulted | \ | unfaulted | \ | faulted |
+ * |-----------| / |-----------| / |-----------|
+ * ptr \ ptr2 \ ptr3
+ */
+ ptr[0] = 'x';
+ ptr3[0] = 'x';
+
+ /*
+ * Move ptr3 back into place, leaving a place for ptr2:
+ * \
+ * |-----------| |-----------| / |-----------|
+ * | faulted | | faulted | \ | unfaulted |
+ * |-----------| |-----------| / |-----------|
+ * ptr ptr3 \ ptr2
+ */
+ ptr3 = sys_mremap(ptr3, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &ptr[10 * page_size]);
+ ASSERT_NE(ptr3, MAP_FAILED);
+
+ /*
+ * Finally, move ptr2 into place:
+ *
+ * |-----------|-----------|-----------|
+ * | faulted | unfaulted | faulted |
+ * |-----------|-----------|-----------|
+ * ptr ptr2 ptr3
+ *
+ * It should merge, but only ptr, ptr2:
+ *
+ * |-----------------------|-----------|
+ * | faulted | unfaulted |
+ * |-----------------------|-----------|
+ */
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &ptr[5 * page_size]);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ ASSERT_TRUE(find_vma_procmap(procmap, ptr));
+ ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr);
+ ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 10 * page_size);
+
+ ASSERT_TRUE(find_vma_procmap(procmap, ptr3));
+ ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr3);
+ ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr3 + 5 * page_size);
+}
+
+TEST_F(merge, mremap_unfaulted_between_faulted_unfaulted)
+{
+ unsigned int page_size = self->page_size;
+ char *carveout = self->carveout;
+ struct procmap_fd *procmap = &self->procmap;
+ char *ptr, *ptr2, *ptr3;
+
+ /*
+ * Map three distinct areas:
+ *
+ * |-----------| |-----------| |-----------|
+ * | unfaulted | | unfaulted | | unfaulted |
+ * |-----------| |-----------| |-----------|
+ * ptr ptr2 ptr3
+ */
+ ptr = mmap(&carveout[page_size], 5 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr, MAP_FAILED);
+ ptr2 = mmap(&carveout[7 * page_size], 5 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr2, MAP_FAILED);
+ ptr3 = mmap(&carveout[14 * page_size], 5 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr3, MAP_FAILED);
+
+ /* Offset ptr3 further away. */
+ ptr3 = sys_mremap(ptr3, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, ptr3 + page_size * 2000);
+ ASSERT_NE(ptr3, MAP_FAILED);
+
+
+ /* Offset ptr2 further away. */
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, ptr2 + page_size * 1000);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ /*
+ * Fault in ptr:
+ * \ \
+ * |-----------| / |-----------| / |-----------|
+ * | faulted | \ | unfaulted | \ | unfaulted |
+ * |-----------| / |-----------| / |-----------|
+ * ptr \ ptr2 \ ptr3
+ */
+ ptr[0] = 'x';
+
+ /*
+ * Move ptr3 back into place, leaving a place for ptr2:
+ * \
+ * |-----------| |-----------| / |-----------|
+ * | faulted | | unfaulted | \ | unfaulted |
+ * |-----------| |-----------| / |-----------|
+ * ptr ptr3 \ ptr2
+ */
+ ptr3 = sys_mremap(ptr3, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &ptr[10 * page_size]);
+ ASSERT_NE(ptr3, MAP_FAILED);
+
+ /*
+ * Finally, move ptr2 into place:
+ *
+ * |-----------|-----------|-----------|
+ * | faulted | unfaulted | unfaulted |
+ * |-----------|-----------|-----------|
+ * ptr ptr2 ptr3
+ *
+ * It should merge:
+ *
+ * |-----------------------------------|
+ * | faulted |
+ * |-----------------------------------|
+ */
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &ptr[5 * page_size]);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ ASSERT_TRUE(find_vma_procmap(procmap, ptr));
+ ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr);
+ ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 15 * page_size);
+}
+
+TEST_F(merge, mremap_unfaulted_between_correctly_placed_faulted)
+{
+ unsigned int page_size = self->page_size;
+ char *carveout = self->carveout;
+ struct procmap_fd *procmap = &self->procmap;
+ char *ptr, *ptr2;
+
+ /*
+ * Map one larger area:
+ *
+ * |-----------------------------------|
+ * | unfaulted |
+ * |-----------------------------------|
+ */
+ ptr = mmap(&carveout[page_size], 15 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr, MAP_FAILED);
+
+ /*
+ * Fault in ptr:
+ *
+ * |-----------------------------------|
+ * | faulted |
+ * |-----------------------------------|
+ */
+ ptr[0] = 'x';
+
+ /*
+ * Unmap middle:
+ *
+ * |-----------| |-----------|
+ * | faulted | | faulted |
+ * |-----------| |-----------|
+ *
+ * Now the faulted areas are compatible with each other (anon_vma the
+ * same, vma->vm_pgoff equal to virtual page offset).
+ */
+ ASSERT_EQ(munmap(&ptr[5 * page_size], 5 * page_size), 0);
+
+ /*
+ * Map a new area, ptr2:
+ * \
+ * |-----------| |-----------| / |-----------|
+ * | faulted | | faulted | \ | unfaulted |
+ * |-----------| |-----------| / |-----------|
+ * ptr \ ptr2
+ */
+ ptr2 = mmap(&carveout[20 * page_size], 5 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ /*
+ * Finally, move ptr2 into place:
+ *
+ * |-----------|-----------|-----------|
+ * | faulted | unfaulted | faulted |
+ * |-----------|-----------|-----------|
+ * ptr ptr2 ptr3
+ *
+ * It should merge:
+ *
+ * |-----------------------------------|
+ * | faulted |
+ * |-----------------------------------|
+ */
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &ptr[5 * page_size]);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ ASSERT_TRUE(find_vma_procmap(procmap, ptr));
+ ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr);
+ ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 15 * page_size);
+}
+
+TEST_F(merge, mremap_correct_placed_faulted)
+{
+ unsigned int page_size = self->page_size;
+ char *carveout = self->carveout;
+ struct procmap_fd *procmap = &self->procmap;
+ char *ptr, *ptr2, *ptr3;
+
+ /*
+ * Map one larger area:
+ *
+ * |-----------------------------------|
+ * | unfaulted |
+ * |-----------------------------------|
+ */
+ ptr = mmap(&carveout[page_size], 15 * page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr, MAP_FAILED);
+
+ /*
+ * Fault in ptr:
+ *
+ * |-----------------------------------|
+ * | faulted |
+ * |-----------------------------------|
+ */
+ ptr[0] = 'x';
+
+ /*
+ * Offset the final and middle 5 pages further away:
+ * \ \
+ * |-----------| / |-----------| / |-----------|
+ * | faulted | \ | faulted | \ | faulted |
+ * |-----------| / |-----------| / |-----------|
+ * ptr \ ptr2 \ ptr3
+ */
+ ptr3 = &ptr[10 * page_size];
+ ptr3 = sys_mremap(ptr3, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, ptr3 + page_size * 2000);
+ ASSERT_NE(ptr3, MAP_FAILED);
+ ptr2 = &ptr[5 * page_size];
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, ptr2 + page_size * 1000);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ /*
+ * Move ptr2 into its correct place:
+ * \
+ * |-----------|-----------| / |-----------|
+ * | faulted | faulted | \ | faulted |
+ * |-----------|-----------| / |-----------|
+ * ptr ptr2 \ ptr3
+ *
+ * It should merge:
+ * \
+ * |-----------------------| / |-----------|
+ * | faulted | \ | faulted |
+ * |-----------------------| / |-----------|
+ * ptr \ ptr3
+ */
+
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &ptr[5 * page_size]);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ ASSERT_TRUE(find_vma_procmap(procmap, ptr));
+ ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr);
+ ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 10 * page_size);
+
+ /*
+ * Now move ptr out of place:
+ * \ \
+ * |-----------| / |-----------| / |-----------|
+ * | faulted | \ | faulted | \ | faulted |
+ * |-----------| / |-----------| / |-----------|
+ * ptr2 \ ptr \ ptr3
+ */
+ ptr = sys_mremap(ptr, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, ptr + page_size * 1000);
+ ASSERT_NE(ptr, MAP_FAILED);
+
+ /*
+ * Now move ptr back into place:
+ * \
+ * |-----------|-----------| / |-----------|
+ * | faulted | faulted | \ | faulted |
+ * |-----------|-----------| / |-----------|
+ * ptr ptr2 \ ptr3
+ *
+ * It should merge:
+ * \
+ * |-----------------------| / |-----------|
+ * | faulted | \ | faulted |
+ * |-----------------------| / |-----------|
+ * ptr \ ptr3
+ */
+ ptr = sys_mremap(ptr, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &carveout[page_size]);
+ ASSERT_NE(ptr, MAP_FAILED);
+
+ ASSERT_TRUE(find_vma_procmap(procmap, ptr));
+ ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr);
+ ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 10 * page_size);
+
+ /*
+ * Now move ptr out of place again:
+ * \ \
+ * |-----------| / |-----------| / |-----------|
+ * | faulted | \ | faulted | \ | faulted |
+ * |-----------| / |-----------| / |-----------|
+ * ptr2 \ ptr \ ptr3
+ */
+ ptr = sys_mremap(ptr, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, ptr + page_size * 1000);
+ ASSERT_NE(ptr, MAP_FAILED);
+
+ /*
+ * Now move ptr3 back into place:
+ * \
+ * |-----------|-----------| / |-----------|
+ * | faulted | faulted | \ | faulted |
+ * |-----------|-----------| / |-----------|
+ * ptr2 ptr3 \ ptr
+ *
+ * It should merge:
+ * \
+ * |-----------------------| / |-----------|
+ * | faulted | \ | faulted |
+ * |-----------------------| / |-----------|
+ * ptr2 \ ptr
+ */
+ ptr3 = sys_mremap(ptr3, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &ptr2[5 * page_size]);
+ ASSERT_NE(ptr3, MAP_FAILED);
+
+ ASSERT_TRUE(find_vma_procmap(procmap, ptr2));
+ ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr2);
+ ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr2 + 10 * page_size);
+
+ /*
+ * Now move ptr back into place:
+ *
+ * |-----------|-----------------------|
+ * | faulted | faulted |
+ * |-----------|-----------------------|
+ * ptr ptr2
+ *
+ * It should merge:
+ *
+ * |-----------------------------------|
+ * | faulted |
+ * |-----------------------------------|
+ * ptr
+ */
+ ptr = sys_mremap(ptr, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &carveout[page_size]);
+ ASSERT_NE(ptr, MAP_FAILED);
+
+ ASSERT_TRUE(find_vma_procmap(procmap, ptr));
+ ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr);
+ ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 15 * page_size);
+
+ /*
+ * Now move ptr2 out of the way:
+ * \
+ * |-----------| |-----------| / |-----------|
+ * | faulted | | faulted | \ | faulted |
+ * |-----------| |-----------| / |-----------|
+ * ptr ptr3 \ ptr2
+ */
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, ptr2 + page_size * 1000);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ /*
+ * Now move it back:
+ *
+ * |-----------|-----------|-----------|
+ * | faulted | faulted | faulted |
+ * |-----------|-----------|-----------|
+ * ptr ptr2 ptr3
+ *
+ * It should merge:
+ *
+ * |-----------------------------------|
+ * | faulted |
+ * |-----------------------------------|
+ * ptr
+ */
+ ptr2 = sys_mremap(ptr2, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &ptr[5 * page_size]);
+ ASSERT_NE(ptr2, MAP_FAILED);
+
+ ASSERT_TRUE(find_vma_procmap(procmap, ptr));
+ ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr);
+ ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 15 * page_size);
+
+ /*
+ * Move ptr3 out of place:
+ * \
+ * |-----------------------| / |-----------|
+ * | faulted | \ | faulted |
+ * |-----------------------| / |-----------|
+ * ptr \ ptr3
+ */
+ ptr3 = sys_mremap(ptr3, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, ptr3 + page_size * 1000);
+ ASSERT_NE(ptr3, MAP_FAILED);
+
+ /*
+ * Now move it back:
+ *
+ * |-----------|-----------|-----------|
+ * | faulted | faulted | faulted |
+ * |-----------|-----------|-----------|
+ * ptr ptr2 ptr3
+ *
+ * It should merge:
+ *
+ * |-----------------------------------|
+ * | faulted |
+ * |-----------------------------------|
+ * ptr
+ */
+ ptr3 = sys_mremap(ptr3, 5 * page_size, 5 * page_size,
+ MREMAP_MAYMOVE | MREMAP_FIXED, &ptr[10 * page_size]);
+ ASSERT_NE(ptr3, MAP_FAILED);
+
+ ASSERT_TRUE(find_vma_procmap(procmap, ptr));
+ ASSERT_EQ(procmap->query.vma_start, (unsigned long)ptr);
+ ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr + 15 * page_size);
+}
+
TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
index 5492e3f784df..1d434772fa54 100644
--- a/tools/testing/selftests/mm/vm_util.c
+++ b/tools/testing/selftests/mm/vm_util.c
@@ -524,3 +524,11 @@ int read_sysfs(const char *file_path, unsigned long *val)
return 0;
}
+
+void *sys_mremap(void *old_address, unsigned long old_size,
+ unsigned long new_size, int flags, void *new_address)
+{
+ return (void *)syscall(__NR_mremap, (unsigned long)old_address,
+ old_size, new_size, flags,
+ (unsigned long)new_address);
+}
diff --git a/tools/testing/selftests/mm/vm_util.h b/tools/testing/selftests/mm/vm_util.h
index b8136d12a0f8..797c24215b17 100644
--- a/tools/testing/selftests/mm/vm_util.h
+++ b/tools/testing/selftests/mm/vm_util.h
@@ -117,6 +117,9 @@ static inline void log_test_result(int result)
ksft_test_result_report(result, "%s\n", test_name);
}
+void *sys_mremap(void *old_address, unsigned long old_size,
+ unsigned long new_size, int flags, void *new_address);
+
/*
* On ppc64 this will only work with radix 2M hugepage size
*/
--
2.50.0
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