mm: percpu: use kmemleak_ignore_phys() instead of kmemleak_free()

Kmemleak recently added a rbtree to store the objects allocted with
physical address.  Those objects can't be freed with kmemleak_free().

According to the comments, percpu allocations are tracked by kmemleak
separately.  Kmemleak_free() was used to avoid the unnecessary
tracking.  If kmemleak_free() fails, those objects would be scanned by
kmemleak, which is unnecessary but shouldn't lead to other effects.

Use kmemleak_ignore_phys() instead of kmemleak_free() for those
objects.

Link: https://lkml.kernel.org/r/20220705113158.127600-1-patrick.wang.shcn@gmail.com
Fixes: 0c24e061 ("mm: kmemleak: add rbtree and store physical address for objects allocated with PA")
Signed-off-by: Patrick Wang <patrick.wang.shcn@gmail.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/percpu.c

@@ -3104,7 +3104,7 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
 			goto out_free_areas;
 		}
 		/* kmemleak tracks the percpu allocations separately */
-		kmemleak_free(ptr);
+		kmemleak_ignore_phys(__pa(ptr));
 		areas[group] = ptr;
 
 		base = min(ptr, base);
@@ -3304,7 +3304,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size, pcpu_fc_cpu_to_node_fn_t
 				goto enomem;
 			}
 			/* kmemleak tracks the percpu allocations separately */
-			kmemleak_free(ptr);
+			kmemleak_ignore_phys(__pa(ptr));
 			pages[j++] = virt_to_page(ptr);
 		}
 	}
@@ -3417,7 +3417,7 @@ void __init setup_per_cpu_areas(void)
 	if (!ai || !fc)
 		panic("Failed to allocate memory for percpu areas.");
 	/* kmemleak tracks the percpu allocations separately */
-	kmemleak_free(fc);
+	kmemleak_ignore_phys(__pa(fc));
 
 	ai->dyn_size = unit_size;
 	ai->unit_size = unit_size;