Commit 4c2e9a67 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Andrew Morton
Browse files

lib/stackdepot: rename hash table constants and variables 

Give more meaningful names to hash table-related constants and variables:

1. Rename STACK_HASH_SCALE to STACK_HASH_TABLE_SCALE to point out that it
   is related to scaling the hash table.

2. Rename STACK_HASH_ORDER_MIN/MAX to STACK_BUCKET_NUMBER_ORDER_MIN/MAX
   to point out that it is related to the number of hash table buckets.

3. Rename stack_hash_order to stack_bucket_number_order for the same
   reason as #2.

No functional changes.

Link: https://lkml.kernel.org/r/f166dd6f3cb2378aea78600714393dd568c33ee9.1676063693.git.andreyknvl@google.com


Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: default avatarAlexander Potapenko <glider@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 0d249ac0

lib/stackdepot.c

+21 −21
Original line number Diff line number Diff line
@@ -76,17 +76,17 @@ static bool __stack_depot_early_init_requested __initdata = IS_ENABLED(CONFIG_ST 
static bool __stack_depot_early_init_passed __initdata;



/* Use one hash table bucket per 16 KB of memory. */

#define STACK_HASH_SCALE	14

#define STACK_HASH_TABLE_SCALE 14

/* Limit the number of buckets between 4K and 1M. */

#define STACK_HASH_ORDER_MIN	12

#define STACK_HASH_ORDER_MAX	20

#define STACK_BUCKET_NUMBER_ORDER_MIN 12

#define STACK_BUCKET_NUMBER_ORDER_MAX 20

/* Initial seed for jhash2. */

#define STACK_HASH_SEED 0x9747b28c



/* Hash table of pointers to stored stack traces. */

static struct stack_record **stack_table;

/* Fixed order of the number of table buckets. Used when KASAN is enabled. */

static unsigned int stack_hash_order;

static unsigned int stack_bucket_number_order;

/* Hash mask for indexing the table. */

static unsigned int stack_hash_mask;
@@ -137,28 +137,28 @@ int __init stack_depot_early_init(void) 
	 * in fuzzing scenarios, which leads to a large number of different

	 * stack traces being stored in stack depot.

	 */

	if (kasan_enabled() && !stack_hash_order)

		stack_hash_order = STACK_HASH_ORDER_MAX;

	if (kasan_enabled() && !stack_bucket_number_order)

		stack_bucket_number_order = STACK_BUCKET_NUMBER_ORDER_MAX;



	if (!__stack_depot_early_init_requested || stack_depot_disabled)

		return 0;



	/*

	 * If stack_hash_order is not set, leave entries as 0 to rely on the

	 * automatic calculations performed by alloc_large_system_hash.

	 * If stack_bucket_number_order is not set, leave entries as 0 to rely

	 * on the automatic calculations performed by alloc_large_system_hash.

	 */

	if (stack_hash_order)

		entries = 1UL << stack_hash_order;

	if (stack_bucket_number_order)

		entries = 1UL << stack_bucket_number_order;

	pr_info("allocating hash table via alloc_large_system_hash\n");

	stack_table = alloc_large_system_hash("stackdepot",

						sizeof(struct stack_record *),

						entries,

						STACK_HASH_SCALE,

						STACK_HASH_TABLE_SCALE,

						HASH_EARLY | HASH_ZERO,

						NULL,

						&stack_hash_mask,

						1UL << STACK_HASH_ORDER_MIN,

						1UL << STACK_HASH_ORDER_MAX);

						1UL << STACK_BUCKET_NUMBER_ORDER_MIN,

						1UL << STACK_BUCKET_NUMBER_ORDER_MAX);

	if (!stack_table) {

		pr_err("hash table allocation failed, disabling\n");

		stack_depot_disabled = true;
@@ -181,13 +181,13 @@ int stack_depot_init(void) 
		goto out_unlock;



	/*

	 * Similarly to stack_depot_early_init, use stack_hash_order

	 * Similarly to stack_depot_early_init, use stack_bucket_number_order

	 * if assigned, and rely on automatic scaling otherwise.

	 */

	if (stack_hash_order) {

		entries = 1UL << stack_hash_order;

	if (stack_bucket_number_order) {

		entries = 1UL << stack_bucket_number_order;

	} else {

		int scale = STACK_HASH_SCALE;

		int scale = STACK_HASH_TABLE_SCALE;



		entries = nr_free_buffer_pages();

		entries = roundup_pow_of_two(entries);
@@ -198,10 +198,10 @@ int stack_depot_init(void) 
			entries <<= (PAGE_SHIFT - scale);

	}



	if (entries < 1UL << STACK_HASH_ORDER_MIN)

		entries = 1UL << STACK_HASH_ORDER_MIN;

	if (entries > 1UL << STACK_HASH_ORDER_MAX)

		entries = 1UL << STACK_HASH_ORDER_MAX;

	if (entries < 1UL << STACK_BUCKET_NUMBER_ORDER_MIN)

		entries = 1UL << STACK_BUCKET_NUMBER_ORDER_MIN;

	if (entries > 1UL << STACK_BUCKET_NUMBER_ORDER_MAX)

		entries = 1UL << STACK_BUCKET_NUMBER_ORDER_MAX;



	pr_info("allocating hash table of %lu entries via kvcalloc\n", entries);

	stack_table = kvcalloc(entries, sizeof(struct stack_record *), GFP_KERNEL);