Merge tag 'printk-for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/printk...

[sfrench/cifs-2.6.git] / lib / vsprintf.c

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index c414a8d9f1ea912a3fe2cba5e4d8abc9bbeb83bb..24f37bab8bc1f7a9ae5c533e6f155fa2aa30e83b 100644 (file)
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -750,37 +750,42 @@ static int __init debug_boot_weak_hash_enable(char *str)
 }
 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable);
 
-static DEFINE_STATIC_KEY_FALSE(filled_random_ptr_key);
+static bool filled_random_ptr_key __read_mostly;
+static siphash_key_t ptr_key __read_mostly;
+static void fill_ptr_key_workfn(struct work_struct *work);
+static DECLARE_DELAYED_WORK(fill_ptr_key_work, fill_ptr_key_workfn);
 
-static void enable_ptr_key_workfn(struct work_struct *work)
+static void fill_ptr_key_workfn(struct work_struct *work)
 {
-       static_branch_enable(&filled_random_ptr_key);
+       if (!rng_is_initialized()) {
+               queue_delayed_work(system_unbound_wq, &fill_ptr_key_work, HZ  * 2);
+               return;
+       }
+
+       get_random_bytes(&ptr_key, sizeof(ptr_key));
+
+       /* Pairs with smp_rmb() before reading ptr_key. */
+       smp_wmb();
+       WRITE_ONCE(filled_random_ptr_key, true);
+}
+
+static int __init vsprintf_init_hashval(void)
+{
+       fill_ptr_key_workfn(NULL);
+       return 0;
 }
+subsys_initcall(vsprintf_init_hashval)
 
 /* Maps a pointer to a 32 bit unique identifier. */
 static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
 {
-       static siphash_key_t ptr_key __read_mostly;
        unsigned long hashval;
 
-       if (!static_branch_likely(&filled_random_ptr_key)) {
-               static bool filled = false;
-               static DEFINE_SPINLOCK(filling);
-               static DECLARE_WORK(enable_ptr_key_work, enable_ptr_key_workfn);
-               unsigned long flags;
-
-               if (!system_unbound_wq || !rng_is_initialized() ||
-                   !spin_trylock_irqsave(&filling, flags))
-                       return -EAGAIN;
-
-               if (!filled) {
-                       get_random_bytes(&ptr_key, sizeof(ptr_key));
-                       queue_work(system_unbound_wq, &enable_ptr_key_work);
-                       filled = true;
-               }
-               spin_unlock_irqrestore(&filling, flags);
-       }
+       if (!READ_ONCE(filled_random_ptr_key))
+               return -EBUSY;
 
+       /* Pairs with smp_wmb() after writing ptr_key. */
+       smp_rmb();
 
 #ifdef CONFIG_64BIT
        hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
@@ -1189,7 +1194,7 @@ char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
 }
 
 static noinline_for_stack
-char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
+char *bitmap_string(char *buf, char *end, const unsigned long *bitmap,
                    struct printf_spec spec, const char *fmt)
 {
        const int CHUNKSZ = 32;
@@ -1233,7 +1238,7 @@ char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
 }
 
 static noinline_for_stack
-char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
+char *bitmap_list_string(char *buf, char *end, const unsigned long *bitmap,
                         struct printf_spec spec, const char *fmt)
 {
        int nr_bits = max_t(int, spec.field_width, 0);