@@ -73,6 +73,14 @@ static int next_slab_inited;
static size_t depot_offset;
static DEFINE_RAW_SPINLOCK(depot_lock);
+static size_t stack_hash_size = (1 << CONFIG_STACK_HASH_ORDER);
+static inline size_t stack_hash_mask(void)
+{
+ return stack_hash_size - 1;
+}
+
+#define STACK_HASH_SEED 0x9747b28c
+
static bool init_stack_slab(void **prealloc)
{
if (!*prealloc)
@@ -142,10 +150,6 @@ depot_alloc_stack(unsigned long *entries, int size, u32 hash, void **prealloc)
return stack;
}
-#define STACK_HASH_SIZE (1L << CONFIG_STACK_HASH_ORDER)
-#define STACK_HASH_MASK (STACK_HASH_SIZE - 1)
-#define STACK_HASH_SEED 0x9747b28c
-
static bool stack_depot_disable;
static struct stack_record **stack_table;
@@ -172,18 +176,28 @@ __ref int stack_depot_init(void)
mutex_lock(&stack_depot_init_mutex);
if (!stack_depot_disable && !stack_table) {
- size_t size = (STACK_HASH_SIZE * sizeof(struct stack_record *));
+ size_t size = (stack_hash_size * sizeof(struct stack_record *));
int i;
if (slab_is_available()) {
pr_info("Stack Depot allocating hash table with kvmalloc\n");
stack_table = kvmalloc(size, GFP_KERNEL);
+ } else if (totalram_pages() > 0) {
+ /* Reduce size because vmalloc may be unavailable */
+ size = min_t(size_t, size, PAGE_SIZE << (MAX_ORDER - 1));
+ stack_hash_size = size / sizeof(struct stack_record *);
+
+ pr_info("Stack Depot allocating hash table with __get_free_pages\n");
+ stack_table = (struct stack_record **)
+ __get_free_pages(GFP_KERNEL, get_order(size));
} else {
pr_info("Stack Depot allocating hash table with memblock_alloc\n");
stack_table = memblock_alloc(size, SMP_CACHE_BYTES);
}
+
if (stack_table) {
- for (i = 0; i < STACK_HASH_SIZE; i++)
+ pr_info("Stack Depot hash table size=%zu\n", stack_hash_size);
+ for (i = 0; i < stack_hash_size; i++)
stack_table[i] = NULL;
} else {
pr_err("Stack Depot hash table allocation failed, disabling\n");
@@ -363,7 +377,7 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries,
goto fast_exit;
hash = hash_stack(entries, nr_entries);
- bucket = &stack_table[hash & STACK_HASH_MASK];
+ bucket = &stack_table[hash & stack_hash_mask()];
/*
* Fast path: look the stack trace up without locking.
After commit 2dba5eb1c73b ("lib/stackdepot: allow optional init and stack_table allocation by kvmalloc()"), stack_depot_init() is called later if CONFIG_STACKDEPOT_ALWAYS_INIT=n to remove unnecessary memory usage. It allocates stack_table using memblock_alloc() or kvmalloc() depending on availability of slab allocator. But when stack_depot_init() is called while creating boot slab caches, both slab allocator and memblock is not available. So kernel crashes. Allocate stack_table from page allocator when both slab allocator and memblock is unavailable. Limit size of stack_table when using page allocator because vmalloc() is also unavailable in kmem_cache_init(). It must not be larger than (PAGE_SIZE << (MAX_ORDER - 1)). This patch was tested on both CONFIG_STACKDEPOT_ALWAYS_INIT=y and n. [ lkp@intel.com: Fix W=1 build warning ] Fixes: 2dba5eb1c73b ("lib/stackdepot: allow optional init and stack_table allocation by kvmalloc()") Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> --- lib/stackdepot.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-)