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From:   Peng Zhang <zhangpeng.00@bytedance.com>
To:     Liam.Howlett@oracle.com, corbet@lwn.net, akpm@linux-foundation.org,
        willy@infradead.org, brauner@kernel.org, surenb@google.com,
        michael.christie@oracle.com, mjguzik@gmail.com,
        mathieu.desnoyers@efficios.com, npiggin@gmail.com,
        peterz@infradead.org, oliver.sang@intel.com, mst@redhat.com
Cc:     zhangpeng.00@bytedance.com, maple-tree@lists.infradead.org,
        linux-mm@kvack.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH v4 04/10] radix tree test suite: Align kmem_cache_alloc_bulk() with kernel behavior.
Date:   Mon,  9 Oct 2023 17:03:14 +0800
Message-Id: <20231009090320.64565-5-zhangpeng.00@bytedance.com>
In-Reply-To: <20231009090320.64565-1-zhangpeng.00@bytedance.com>
References: <20231009090320.64565-1-zhangpeng.00@bytedance.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

When kmem_cache_alloc_bulk() fails to allocate, leave the freed pointers
in the array. This enables a more accurate simulation of the kernel's
behavior and allows for testing potential double-free scenarios.

Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
---
 tools/testing/radix-tree/linux.c | 45 +++++++++++++++++++++++---------
 1 file changed, 33 insertions(+), 12 deletions(-)

diff --git a/tools/testing/radix-tree/linux.c b/tools/testing/radix-tree/linux.c
index 61fe2601cb3a..4eb442206d01 100644
--- a/tools/testing/radix-tree/linux.c
+++ b/tools/testing/radix-tree/linux.c
@@ -93,13 +93,9 @@ void *kmem_cache_alloc_lru(struct kmem_cache *cachep, struct list_lru *lru,
 	return p;
 }
 
-void kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
+void __kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
 {
 	assert(objp);
-	uatomic_dec(&nr_allocated);
-	uatomic_dec(&cachep->nr_allocated);
-	if (kmalloc_verbose)
-		printf("Freeing %p to slab\n", objp);
 	if (cachep->nr_objs > 10 || cachep->align) {
 		memset(objp, POISON_FREE, cachep->size);
 		free(objp);
@@ -111,6 +107,15 @@ void kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
 	}
 }
 
+void kmem_cache_free_locked(struct kmem_cache *cachep, void *objp)
+{
+	uatomic_dec(&nr_allocated);
+	uatomic_dec(&cachep->nr_allocated);
+	if (kmalloc_verbose)
+		printf("Freeing %p to slab\n", objp);
+	__kmem_cache_free_locked(cachep, objp);
+}
+
 void kmem_cache_free(struct kmem_cache *cachep, void *objp)
 {
 	pthread_mutex_lock(&cachep->lock);
@@ -141,18 +146,17 @@ int kmem_cache_alloc_bulk(struct kmem_cache *cachep, gfp_t gfp, size_t size,
 	if (kmalloc_verbose)
 		pr_debug("Bulk alloc %lu\n", size);
 
-	if (!(gfp & __GFP_DIRECT_RECLAIM)) {
-		if (cachep->non_kernel < size)
-			return 0;
-
-		cachep->non_kernel -= size;
-	}
-
 	pthread_mutex_lock(&cachep->lock);
 	if (cachep->nr_objs >= size) {
 		struct radix_tree_node *node;
 
 		for (i = 0; i < size; i++) {
+			if (!(gfp & __GFP_DIRECT_RECLAIM)) {
+				if (!cachep->non_kernel)
+					break;
+				cachep->non_kernel--;
+			}
+
 			node = cachep->objs;
 			cachep->nr_objs--;
 			cachep->objs = node->parent;
@@ -163,11 +167,19 @@ int kmem_cache_alloc_bulk(struct kmem_cache *cachep, gfp_t gfp, size_t size,
 	} else {
 		pthread_mutex_unlock(&cachep->lock);
 		for (i = 0; i < size; i++) {
+			if (!(gfp & __GFP_DIRECT_RECLAIM)) {
+				if (!cachep->non_kernel)
+					break;
+				cachep->non_kernel--;
+			}
+
 			if (cachep->align) {
 				posix_memalign(&p[i], cachep->align,
 					       cachep->size);
 			} else {
 				p[i] = malloc(cachep->size);
+				if (!p[i])
+					break;
 			}
 			if (cachep->ctor)
 				cachep->ctor(p[i]);
@@ -176,6 +188,15 @@ int kmem_cache_alloc_bulk(struct kmem_cache *cachep, gfp_t gfp, size_t size,
 		}
 	}
 
+	if (i < size) {
+		size = i;
+		pthread_mutex_lock(&cachep->lock);
+		for (i = 0; i < size; i++)
+			__kmem_cache_free_locked(cachep, p[i]);
+		pthread_mutex_unlock(&cachep->lock);
+		return 0;
+	}
+
 	for (i = 0; i < size; i++) {
 		uatomic_inc(&nr_allocated);
 		uatomic_inc(&cachep->nr_allocated);
-- 
2.20.1