This may trigger the case fixed by commit 48c3b583bbdd ("mm/memblock:
fix overlapping allocation when doubling reserved array").
This is done by adding the 129th reserve region into memblock.memory. If
memblock_double_array() use this reserve region as new array, it fails.
Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
---
v3:
* rename MEM_ALLOC_SIZE to PHYS_MEM_SIZE
* add test description
---
tools/testing/memblock/tests/basic_api.c | 151 +++++++++++++++++++++++
tools/testing/memblock/tests/common.c | 4 +-
tools/testing/memblock/tests/common.h | 1 +
3 files changed, 154 insertions(+), 2 deletions(-)
diff --git a/tools/testing/memblock/tests/basic_api.c b/tools/testing/memblock/tests/basic_api.c
index bd3ebbf6b697..fdac82656d15 100644
--- a/tools/testing/memblock/tests/basic_api.c
+++ b/tools/testing/memblock/tests/basic_api.c
@@ -1088,6 +1088,156 @@ static int memblock_reserve_all_locations_check(void)
return 0;
}
+/*
+ * A test that trying to reserve the 129th memory block at all locations.
+ * Expect to trigger memblock_double_array() to double the
+ * memblock.memory.max, find a new valid memory as reserved.regions. And make
+ * sure it doesn't conflict with the range we want to reserve.
+ *
+ * For example, we have 128 regions in reserved and now want to reserve
+ * the skipped one. Since reserved is full, memblock_double_array() would find
+ * an available range in memory for the new array. We intended to put two
+ * ranges in memory with one is the exact range of the skipped one. Before
+ * commit 48c3b583bbdd ("mm/memblock: fix overlapping allocation when doubling
+ * reserved array"), the new array would sits in the skipped range which is a
+ * conflict. The expected new array should be allocated from memory.regions[0].
+ *
+ * 0 1
+ * memory +-------+ +-------+
+ * | 32K | | 32K |
+ * +-------+ ------+-------+-------+-------+
+ * |<-32K->|<-32K->|<-32K->|
+ *
+ * 0 skipped 127
+ * reserved +-------+ ......... +-------+
+ * | 32K | . 32K . ... | 32K |
+ * +-------+-------+-------+ +-------+
+ * |<-32K->|
+ * ^
+ * |
+ * |
+ * skipped one
+ */
+/* Keep the gap so these memory region will not be merged. */
+#define MEMORY_BASE_OFFSET(idx, offset) ((offset) + (MEM_SIZE * 2) * (idx))
+static int memblock_reserve_many_may_conflict_check(void)
+{
+ int i, skip;
+ void *orig_region;
+ struct region r = {
+ .base = SZ_16K,
+ .size = SZ_16K,
+ };
+ phys_addr_t new_reserved_regions_size;
+
+ /*
+ * 0 1 129
+ * +---+ +---+ +---+
+ * |32K| |32K| .. |32K|
+ * +---+ +---+ +---+
+ *
+ * Pre-allocate the range for 129 memory block + one range for double
+ * memblock.reserved.regions at idx 0.
+ */
+ dummy_physical_memory_init();
+ phys_addr_t memory_base = dummy_physical_memory_base();
+ phys_addr_t offset = PAGE_ALIGN(memory_base);
+
+ PREFIX_PUSH();
+
+ /* Reserve the 129th memory block for all possible positions*/
+ for (skip = 1; skip <= INIT_MEMBLOCK_REGIONS + 1; skip++) {
+ reset_memblock_regions();
+ memblock_allow_resize();
+
+ reset_memblock_attributes();
+ /* Add a valid memory region used by double_array(). */
+ memblock_add(MEMORY_BASE_OFFSET(0, offset), MEM_SIZE);
+ /*
+ * Add a memory region which will be reserved as 129th memory
+ * region. This is not expected to be used by double_array().
+ */
+ memblock_add(MEMORY_BASE_OFFSET(skip, offset), MEM_SIZE);
+
+ for (i = 1; i <= INIT_MEMBLOCK_REGIONS + 1; i++) {
+ if (i == skip)
+ continue;
+
+ /* Reserve some fakes memory region to fulfill the memblock. */
+ memblock_reserve(MEMORY_BASE_OFFSET(i, offset), MEM_SIZE);
+
+ if (i < skip) {
+ ASSERT_EQ(memblock.reserved.cnt, i);
+ ASSERT_EQ(memblock.reserved.total_size, i * MEM_SIZE);
+ } else {
+ ASSERT_EQ(memblock.reserved.cnt, i - 1);
+ ASSERT_EQ(memblock.reserved.total_size, (i - 1) * MEM_SIZE);
+ }
+ }
+
+ orig_region = memblock.reserved.regions;
+
+ /* This reserve the 129 memory_region, and makes it double array. */
+ memblock_reserve(MEMORY_BASE_OFFSET(skip, offset), MEM_SIZE);
+
+ /*
+ * This is the memory region size used by the doubled reserved.regions,
+ * and it has been reserved due to it has been used. The size is used to
+ * calculate the total_size that the memblock.reserved have now.
+ */
+ new_reserved_regions_size = PAGE_ALIGN((INIT_MEMBLOCK_REGIONS * 2) *
+ sizeof(struct memblock_region));
+ /*
+ * The double_array() will find a free memory region as the new
+ * reserved.regions, and the used memory region will be reserved, so
+ * there will be one more region exist in the reserved memblock. And the
+ * one more reserved region's size is new_reserved_regions_size.
+ */
+ ASSERT_EQ(memblock.reserved.cnt, INIT_MEMBLOCK_REGIONS + 2);
+ ASSERT_EQ(memblock.reserved.total_size, (INIT_MEMBLOCK_REGIONS + 1) * MEM_SIZE +
+ new_reserved_regions_size);
+ ASSERT_EQ(memblock.reserved.max, INIT_MEMBLOCK_REGIONS * 2);
+
+ /*
+ * The first reserved region is allocated for double array
+ * with the size of new_reserved_regions_size and the base to be
+ * MEMORY_BASE_OFFSET(0, offset) + SZ_32K - new_reserved_regions_size
+ */
+ ASSERT_EQ(memblock.reserved.regions[0].base + memblock.reserved.regions[0].size,
+ MEMORY_BASE_OFFSET(0, offset) + SZ_32K);
+ ASSERT_EQ(memblock.reserved.regions[0].size, new_reserved_regions_size);
+
+ /*
+ * Now memblock_double_array() works fine. Let's check after the
+ * double_array(), the memblock_reserve() still works as normal.
+ */
+ memblock_reserve(r.base, r.size);
+ ASSERT_EQ(memblock.reserved.regions[0].base, r.base);
+ ASSERT_EQ(memblock.reserved.regions[0].size, r.size);
+
+ ASSERT_EQ(memblock.reserved.cnt, INIT_MEMBLOCK_REGIONS + 3);
+ ASSERT_EQ(memblock.reserved.total_size, (INIT_MEMBLOCK_REGIONS + 1) * MEM_SIZE +
+ new_reserved_regions_size +
+ r.size);
+ ASSERT_EQ(memblock.reserved.max, INIT_MEMBLOCK_REGIONS * 2);
+
+ /*
+ * The current reserved.regions is occupying a range of memory that
+ * allocated from dummy_physical_memory_init(). After free the memory,
+ * we must not use it. So restore the origin memory region to make sure
+ * the tests can run as normal and not affected by the double array.
+ */
+ memblock.reserved.regions = orig_region;
+ memblock.reserved.cnt = INIT_MEMBLOCK_RESERVED_REGIONS;
+ }
+
+ dummy_physical_memory_cleanup();
+
+ test_pass_pop();
+
+ return 0;
+}
+
static int memblock_reserve_checks(void)
{
prefix_reset();
@@ -1104,6 +1254,7 @@ static int memblock_reserve_checks(void)
memblock_reserve_near_max_check();
memblock_reserve_many_check();
memblock_reserve_all_locations_check();
+ memblock_reserve_many_may_conflict_check();
prefix_pop();
diff --git a/tools/testing/memblock/tests/common.c b/tools/testing/memblock/tests/common.c
index c2c569f12178..3250c8e5124b 100644
--- a/tools/testing/memblock/tests/common.c
+++ b/tools/testing/memblock/tests/common.c
@@ -61,7 +61,7 @@ void reset_memblock_attributes(void)
static inline void fill_memblock(void)
{
- memset(memory_block.base, 1, MEM_SIZE);
+ memset(memory_block.base, 1, PHYS_MEM_SIZE);
}
void setup_memblock(void)
@@ -103,7 +103,7 @@ void setup_numa_memblock(const unsigned int node_fracs[])
void dummy_physical_memory_init(void)
{
- memory_block.base = malloc(MEM_SIZE);
+ memory_block.base = malloc(PHYS_MEM_SIZE);
assert(memory_block.base);
fill_memblock();
}
diff --git a/tools/testing/memblock/tests/common.h b/tools/testing/memblock/tests/common.h
index b5ec59aa62d7..2f26405562b0 100644
--- a/tools/testing/memblock/tests/common.h
+++ b/tools/testing/memblock/tests/common.h
@@ -12,6 +12,7 @@
#include <../selftests/kselftest.h>
#define MEM_SIZE SZ_32K
+#define PHYS_MEM_SIZE SZ_16M
#define NUMA_NODES 8
#define INIT_MEMBLOCK_REGIONS 128
--
2.34.1
