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| author | Jason A. Donenfeld <Jason@zx2c4.com> | 2016-12-16 06:56:39 +0100 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2016-12-16 06:56:39 +0100 |
| commit | 6033cf88a7971e27ba95233cd82f36be55dfc769 (patch) | |
| tree | c30a75a88076b403a8cfc44ec299ef2a884d728d | |
| parent | 13aa2b4d464c6c606c31b378ea76c23e73f23b2d (diff) | |
hashtables: use counter and int to ensure forward progress
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
| -rw-r--r-- | src/compat.h | 8 | ||||
| -rw-r--r-- | src/hashtables.c | 11 |
2 files changed, 2 insertions, 17 deletions
diff --git a/src/compat.h b/src/compat.h index 5efb4e4..eb4f31b 100644 --- a/src/compat.h +++ b/src/compat.h @@ -25,14 +25,6 @@ #define net_dbg_ratelimited(fmt, ...) do { if (0) no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0) #endif -#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 5, 0) -#include <linux/security.h> -#ifdef GRSECURITY_VERSION -#include <linux/random.h> -#endif -#define get_random_long() (((u64)get_random_int() << 32) | get_random_int()) -#endif - #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0) #define RCU_LOCKDEP_WARN(cond, message) rcu_lockdep_assert(!(cond), message) #endif diff --git a/src/hashtables.c b/src/hashtables.c index 45c9737..534ad55 100644 --- a/src/hashtables.c +++ b/src/hashtables.c @@ -65,16 +65,10 @@ void index_hashtable_init(struct index_hashtable *table) spin_lock_init(&table->lock); } -#if BITS_PER_LONG == 64 -#define get_random_u64() get_random_long() -#else -#define get_random_u64() (((u64)get_random_int() << 32) | get_random_int()) -#endif - __le32 index_hashtable_insert(struct index_hashtable *table, struct index_hashtable_entry *entry) { struct index_hashtable_entry *existing_entry; - u64 rand; + u32 counter = get_random_int(); spin_lock(&table->lock); hlist_del_init_rcu(&entry->index_hash); @@ -84,8 +78,7 @@ __le32 index_hashtable_insert(struct index_hashtable *table, struct index_hashta search_unused_slot: /* First we try to find an unused slot, randomly, while unlocked. */ - rand = get_random_u64(); - entry->index = (__force __le32)siphash_1u64(rand, table->key); + entry->index = (__force __le32)siphash_2u32(get_random_int(), counter++, table->key); hlist_for_each_entry_rcu(existing_entry, index_bucket(table, entry->index), index_hash) { if (existing_entry->index == entry->index) goto search_unused_slot; /* If it's already in use, we continue searching. */ |