mm: postpone the disabling of kmemleak early logging

Commit 8910ae89 ("kmemleak: change some global variables to int"),
in addition to the atomic -> int conversion, moved the disabling of
kmemleak_early_log to the beginning of the kmemleak_init() function,
before the full kmemleak tracing is actually enabled.  In this small
window, kmem_cache_create() is called by kmemleak which triggers
additional memory allocation that are not traced.  This patch restores
the original logic with kmemleak_early_log disabling when kmemleak is
fully functional.

Fixes: 8910ae89 (kmemleak: change some global variables to int)
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Li Zefan <lizefan@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/kmemleak.c

@@ -1775,10 +1775,9 @@ void __init kmemleak_init(void)
 	int i;
 	unsigned long flags;
 
-	kmemleak_early_log = 0;
-
 #ifdef CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF
 	if (!kmemleak_skip_disable) {
+		kmemleak_early_log = 0;
 		kmemleak_disable();
 		return;
 	}
@@ -1796,6 +1795,7 @@ void __init kmemleak_init(void)
 
 	/* the kernel is still in UP mode, so disabling the IRQs is enough */
 	local_irq_save(flags);
+	kmemleak_early_log = 0;
 	if (kmemleak_error) {
 		local_irq_restore(flags);
 		return;