x86: fix backwards merge of GDS/SRSO bit

[platform/kernel/linux-starfive.git] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6806a48..6966881 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6599,7 +6599,21 @@ static void __build_all_zonelists(void *data)
        int nid;
        int __maybe_unused cpu;
        pg_data_t *self = data;
+       unsigned long flags;
 
+       /*
+        * Explicitly disable this CPU's interrupts before taking seqlock
+        * to prevent any IRQ handler from calling into the page allocator
+        * (e.g. GFP_ATOMIC) that could hit zonelist_iter_begin and livelock.
+        */
+       local_irq_save(flags);
+       /*
+        * Explicitly disable this CPU's synchronous printk() before taking
+        * seqlock to prevent any printk() from trying to hold port->lock, for
+        * tty_insert_flip_string_and_push_buffer() on other CPU might be
+        * calling kmalloc(GFP_ATOMIC | __GFP_NOWARN) with port->lock held.
+        */
+       printk_deferred_enter();
        write_seqlock(&zonelist_update_seq);
 
 #ifdef CONFIG_NUMA
@@ -6638,6 +6652,8 @@ static void __build_all_zonelists(void *data)
        }
 
        write_sequnlock(&zonelist_update_seq);
+       printk_deferred_exit();
+       local_irq_restore(flags);
 }
 
 static noinline void __init