Merge branch 'for-6.1-hash-pointer-init' into for-linus
This commit is contained in:
commit
da743a92e5
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@ -750,37 +750,42 @@ static int __init debug_boot_weak_hash_enable(char *str)
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}
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}
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early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
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early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
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static DEFINE_STATIC_KEY_FALSE(filled_random_ptr_key);
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static bool filled_random_ptr_key __read_mostly;
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static siphash_key_t ptr_key __read_mostly;
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static void fill_ptr_key_workfn(struct work_struct *work);
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static DECLARE_DELAYED_WORK(fill_ptr_key_work, fill_ptr_key_workfn);
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static void enable_ptr_key_workfn(struct work_struct *work)
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static void fill_ptr_key_workfn(struct work_struct *work)
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{
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{
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static_branch_enable(&filled_random_ptr_key);
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if (!rng_is_initialized()) {
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queue_delayed_work(system_unbound_wq, &fill_ptr_key_work, HZ * 2);
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return;
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}
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get_random_bytes(&ptr_key, sizeof(ptr_key));
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/* Pairs with smp_rmb() before reading ptr_key. */
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smp_wmb();
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WRITE_ONCE(filled_random_ptr_key, true);
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}
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}
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static int __init vsprintf_init_hashval(void)
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{
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fill_ptr_key_workfn(NULL);
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return 0;
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}
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subsys_initcall(vsprintf_init_hashval)
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/* Maps a pointer to a 32 bit unique identifier. */
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/* Maps a pointer to a 32 bit unique identifier. */
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static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
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static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
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{
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{
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static siphash_key_t ptr_key __read_mostly;
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unsigned long hashval;
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unsigned long hashval;
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if (!static_branch_likely(&filled_random_ptr_key)) {
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if (!READ_ONCE(filled_random_ptr_key))
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static bool filled = false;
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return -EBUSY;
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static DEFINE_SPINLOCK(filling);
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static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
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unsigned long flags;
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if (!system_unbound_wq || !rng_is_initialized() ||
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!spin_trylock_irqsave(&filling, flags))
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return -EAGAIN;
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if (!filled) {
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get_random_bytes(&ptr_key, sizeof(ptr_key));
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queue_work(system_unbound_wq, &enable_ptr_key_work);
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filled = true;
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}
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spin_unlock_irqrestore(&filling, flags);
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}
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/* Pairs with smp_wmb() after writing ptr_key. */
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smp_rmb();
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#ifdef CONFIG_64BIT
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#ifdef CONFIG_64BIT
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hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
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hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
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