From: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>, Jann Horn <jannh@google.com>,
"Liam R . Howlett" <Liam.Howlett@oracle.com>,
Suren Baghdasaryan <surenb@google.com>,
Matthew Wilcox <willy@infradead.org>,
David Hildenbrand <david@redhat.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [RFC PATCH 5/7] tools/testing/selftests: add mremap() cases that merge normally
Date: Fri, 21 Mar 2025 21:54:34 +0000 [thread overview]
Message-ID: <641ba4f558ab671f67267343ae6411a4ea9bec26.1742478846.git.lorenzo.stoakes@oracle.com> (raw)
In-Reply-To: <cover.1742478846.git.lorenzo.stoakes@oracle.com>
Use a direct system call version of mremap() as, when we move to using
MREMAP_[MUST_]RELOCATE_ANON, the glibc wrapper will disallow this.
Also import linux/mman.h (which will amount to the local tools cache of
mman.h) to enusre these header values are available when later added.
Then, add tests asserting all the mremap() merge cases that function
correctly without MREMAP_[MUST_]RELOCATE_ANON.
This constitutes moving around unfaulted VMAs and moving around faulted
VMAs back into position immediately adjacent to VMAs also faulted in with
that moved VMA.
By doing so we provide a baseline set of expectations on mremap()
operations and VMA merge which we can expand upon for
MREMAP_[MUST_]RELOCATE_ANON cases in a subsequent commit.
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
tools/testing/selftests/mm/merge.c | 608 ++++++++++++++++++++++++++++-
1 file changed, 606 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/mm/merge.c b/tools/testing/selftests/mm/merge.c
index 9cc61bdbfba8..7c4f3f93c30d 100644
--- a/tools/testing/selftests/mm/merge.c
+++ b/tools/testing/selftests/mm/merge.c
@@ -8,6 +8,16 @@
#include <sys/mman.h>
#include <sys/wait.h>
#include "vm_util.h"
+#include <linux/mman.h>
+#include <sys/syscall.h>
+
+static 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);
+}
FIXTURE(merge)
{
@@ -20,7 +30,7 @@ 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. */
@@ -29,7 +39,7 @@ 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);
}
@@ -451,4 +461,598 @@ TEST_F(merge, forked_source_vma)
ASSERT_EQ(procmap->query.vma_end, (unsigned long)ptr2 + 5 * 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
--
2.48.1
next prev parent reply other threads:[~2025-03-21 21:55 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-21 21:54 [RFC PATCH 0/7] mm/mremap: introduce more mergeable mremap via MREMAP_RELOCATE_ANON Lorenzo Stoakes
2025-03-21 21:54 ` [RFC PATCH 1/7] " Lorenzo Stoakes
2025-03-22 0:14 ` Jann Horn
2025-03-22 5:33 ` David Hildenbrand
2025-03-22 6:17 ` David Hildenbrand
2025-03-22 7:21 ` Lorenzo Stoakes
2025-03-23 12:53 ` David Hildenbrand
2025-03-31 14:19 ` Lorenzo Stoakes
2025-03-22 7:17 ` Lorenzo Stoakes
2025-03-23 12:49 ` David Hildenbrand
2025-03-31 14:50 ` Lorenzo Stoakes
2025-04-01 19:33 ` David Hildenbrand
2025-04-21 13:12 ` Lorenzo Stoakes
2025-03-22 7:07 ` Lorenzo Stoakes
2025-03-21 21:54 ` [RFC PATCH 2/7] mm/mremap: add MREMAP_MUST_RELOCATE_ANON Lorenzo Stoakes
2025-03-21 21:54 ` [RFC PATCH 3/7] mm/mremap: add MREMAP[_MUST]_RELOCATE_ANON support for THP folios Lorenzo Stoakes
2025-03-21 21:54 ` [RFC PATCH 4/7] tools UAPI: Update copy of linux/mman.h from the kernel sources Lorenzo Stoakes
2025-03-21 21:54 ` Lorenzo Stoakes [this message]
2025-03-21 21:54 ` [RFC PATCH 6/7] tools/testing/selftests: add MREMAP_RELOCATE_ANON merge test cases Lorenzo Stoakes
2025-03-21 21:54 ` [RFC PATCH 7/7] tools/testing/selftests: expand mremap() tests for MREMAP_RELOCATE_ANON Lorenzo Stoakes
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