[PATCH] mm/slab: Initialise random_kmalloc_seed after initcalls

[Huacai Chen <chenhuacai@loongson.cn>]

Hibernation assumes the memory layout after resume be the same as that
before sleep, but CONFIG_RANDOM_KMALLOC_CACHES breaks this assumption.
At least on LoongArch and ARM64 we observed failures of resuming from
hibernation (on LoongArch non-boot CPUs fail to bringup, on ARM64 some
devices are unusable).

software_resume_initcall(), the function which resume the target kernel
is a initcall function. So, move the random_kmalloc_seed initialisation
after all initcalls.

Cc: stable@vger.kernel.org
Fixes: 3c6152940584290668 ("Randomized slab caches for kmalloc()")
Reported-by: Yuli Wang <wangyuli@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---
 init/main.c      | 3 +++
 mm/slab_common.c | 3 ---
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/init/main.c b/init/main.c
index 2a1757826397..1362957bdbe4 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1458,6 +1458,9 @@ static int __ref kernel_init(void *unused)
 	/* need to finish all async __init code before freeing the memory */
 	async_synchronize_full();
 
+#ifdef CONFIG_RANDOM_KMALLOC_CACHES
+	random_kmalloc_seed = get_random_u64();
+#endif
 	system_state = SYSTEM_FREEING_INITMEM;
 	kprobe_free_init_mem();
 	ftrace_free_init_mem();
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 4030907b6b7d..23e324aee218 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -971,9 +971,6 @@ void __init create_kmalloc_caches(void)
 		for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
 			new_kmalloc_cache(i, type);
 	}
-#ifdef CONFIG_RANDOM_KMALLOC_CACHES
-	random_kmalloc_seed = get_random_u64();
-#endif
 
 	/* Kmalloc array is now usable */
 	slab_state = UP;
-- 
2.47.1