Received-SPF: pass (google.com: domain of linux-kernel+bounces-99263-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
From: Pasha Tatashin <pasha.tatashin@soleen.com>
To: linux-kernel@vger.kernel.org,
	linux-mm@kvack.org,
	akpm@linux-foundation.org,
	x86@kernel.org,
	bp@alien8.de,
	brauner@kernel.org,
	bristot@redhat.com,
	bsegall@google.com,
	dave.hansen@linux.intel.com,
	dianders@chromium.org,
	dietmar.eggemann@arm.com,
	eric.devolder@oracle.com,
	hca@linux.ibm.com,
	hch@infradead.org,
	hpa@zytor.com,
	jacob.jun.pan@linux.intel.com,
	jgg@ziepe.ca,
	jpoimboe@kernel.org,
	jroedel@suse.de,
	juri.lelli@redhat.com,
	kent.overstreet@linux.dev,
	kinseyho@google.com,
	kirill.shutemov@linux.intel.com,
	lstoakes@gmail.com,
	luto@kernel.org,
	mgorman@suse.de,
	mic@digikod.net,
	michael.christie@oracle.com,
	mingo@redhat.com,
	mjguzik@gmail.com,
	mst@redhat.com,
	npiggin@gmail.com,
	peterz@infradead.org,
	pmladek@suse.com,
	rick.p.edgecombe@intel.com,
	rostedt@goodmis.org,
	surenb@google.com,
	tglx@linutronix.de,
	urezki@gmail.com,
	vincent.guittot@linaro.org,
	vschneid@redhat.com,
	pasha.tatashin@soleen.com
Subject: [RFC 05/14] fork: check charging success before zeroing stack
Date: Mon, 11 Mar 2024 16:46:29 +0000
Message-ID: <20240311164638.2015063-6-pasha.tatashin@soleen.com>
In-Reply-To: <20240311164638.2015063-1-pasha.tatashin@soleen.com>
References: <20240311164638.2015063-1-pasha.tatashin@soleen.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

No need to do zero cahced stack if memcg charge fails, so move the
charging attempt before the memset operation.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
---
 kernel/fork.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/fork.c b/kernel/fork.c
index a35f4008afa0..6a2f2c85e09f 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -271,6 +271,11 @@ static int alloc_thread_stack_node(struct task_struct *tsk, int node)
 		if (!vm_area)
 			continue;
 
+		if (memcg_charge_kernel_stack(vm_area)) {
+			vfree(vm_area->addr);
+			return -ENOMEM;
+		}
+
 		/* Reset stack metadata. */
 		kasan_unpoison_range(vm_area->addr, THREAD_SIZE);
 
@@ -279,11 +284,6 @@ static int alloc_thread_stack_node(struct task_struct *tsk, int node)
 		/* Clear stale pointers from reused stack. */
 		memset(stack, 0, THREAD_SIZE);
 
-		if (memcg_charge_kernel_stack(vm_area)) {
-			vfree(vm_area->addr);
-			return -ENOMEM;
-		}
-
 		tsk->stack_vm_area = vm_area;
 		tsk->stack = stack;
 		return 0;
-- 
2.44.0.278.ge034bb2e1d-goog