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-rw-r--r--tools/testing/selftests/mm/merge.c682
1 files changed, 679 insertions, 3 deletions
diff --git a/tools/testing/selftests/mm/merge.c b/tools/testing/selftests/mm/merge.c
index bbae66fc5038..cc4253f47f10 100644
--- a/tools/testing/selftests/mm/merge.c
+++ b/tools/testing/selftests/mm/merge.c
@@ -2,15 +2,18 @@
#define _GNU_SOURCE
#include "../kselftest_harness.h"
+#include <linux/prctl.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
+#include <sys/prctl.h>
#include <sys/syscall.h>
#include <sys/wait.h>
#include <linux/perf_event.h>
#include "vm_util.h"
+#include <linux/mman.h>
FIXTURE(merge)
{
@@ -23,7 +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. */
@@ -32,8 +35,13 @@ 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
+ * fails (KSM may be disabled for instance).
+ */
+ prctl(PR_SET_MEMORY_MERGE, 0, 0, 0, 0);
}
TEST_F(merge, mprotect_unfaulted_left)
@@ -470,7 +478,9 @@ TEST_F(merge, handle_uprobe_upon_merged_vma)
ASSERT_GE(fd, 0);
ASSERT_EQ(ftruncate(fd, page_size), 0);
- ASSERT_EQ(read_sysfs("/sys/bus/event_source/devices/uprobe/type", &type), 0);
+ if (read_sysfs("/sys/bus/event_source/devices/uprobe/type", &type) != 0) {
+ SKIP(goto out, "Failed to read uprobe sysfs file, skipping");
+ }
memset(&attr, 0, attr_sz);
attr.size = attr_sz;
@@ -491,8 +501,674 @@ TEST_F(merge, handle_uprobe_upon_merged_vma)
ASSERT_NE(mremap(ptr2, page_size, page_size,
MREMAP_MAYMOVE | MREMAP_FIXED, ptr1), MAP_FAILED);
+out:
close(fd);
remove(probe_file);
}
+TEST_F(merge, ksm_merge)
+{
+ unsigned int page_size = self->page_size;
+ char *carveout = self->carveout;
+ struct procmap_fd *procmap = &self->procmap;
+ char *ptr, *ptr2;
+ int err;
+
+ /*
+ * Map two R/W immediately adjacent to one another, they should
+ * trivially merge:
+ *
+ * |-----------|-----------|
+ * | R/W | R/W |
+ * |-----------|-----------|
+ * ptr ptr2
+ */
+
+ ptr = mmap(&carveout[page_size], page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr, MAP_FAILED);
+ ptr2 = mmap(&carveout[2 * page_size], page_size,
+ PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ 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 + 2 * page_size);
+
+ /* Unmap the second half of this merged VMA. */
+ ASSERT_EQ(munmap(ptr2, page_size), 0);
+
+ /* OK, now enable global KSM merge. We clear this on test teardown. */
+ err = prctl(PR_SET_MEMORY_MERGE, 1, 0, 0, 0);
+ if (err == -1) {
+ int errnum = errno;
+
+ /* Only non-failure case... */
+ ASSERT_EQ(errnum, EINVAL);
+ /* ...but indicates we should skip. */
+ SKIP(return, "KSM memory merging not supported, skipping.");
+ }
+
+ /*
+ * Now map a VMA adjacent to the existing that was just made
+ * VM_MERGEABLE, this should merge as well.
+ */
+ ptr2 = mmap(&carveout[2 * page_size], page_size,
+ PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ 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 + 2 * page_size);
+
+ /* Now this VMA altogether. */
+ ASSERT_EQ(munmap(ptr, 2 * page_size), 0);
+
+ /* Try the same operation as before, asserting this also merges fine. */
+ ptr = mmap(&carveout[page_size], page_size, PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ ASSERT_NE(ptr, MAP_FAILED);
+ ptr2 = mmap(&carveout[2 * page_size], page_size,
+ PROT_READ | PROT_WRITE,
+ MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0);
+ 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 + 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