From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 69-171-232-180.mail-mxout.facebook.com (69-171-232-180.mail-mxout.facebook.com [69.171.232.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E0CA62D5436 for ; Wed, 13 May 2026 04:51:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=69.171.232.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778647882; cv=none; b=Z/4TFP3/y7cd+PJ2thGCgA5TS41JDoextssc3I9mclfYMDYdCQyWJX9ZFvrKh+u+4bhMvTmMryWScFmlDux5BHBd7VB22EmcZVdUxp+A54OCmKQQrPH9fZDNzLoVsp7ilsPLrC09YNrhDtd8ILFS0vISHQEjWVjbM/QgQIaHLhU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778647882; c=relaxed/simple; bh=2RDAlx1faX/H8e46f2YdTHFYeFjWcBfN4FejGE4UyZY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hMAxZEHRyhtOaFf/UiJeOrtFmdCPxBHXUNXwEsfRhqTwC/1TVwmQlGQv+SzD6MZVF47OQNrLJL8QE7W52FkWPX3nCfbwLa59dNiLbXEz7yH4IweaM4RHrJuGQeTtMzAbH3eypvjwH+EkRSgJ1I9QntAWY2+eT/ecqtuA0Oyz7as= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.dev; spf=fail smtp.mailfrom=linux.dev; arc=none smtp.client-ip=69.171.232.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=linux.dev Received: by devvm16039.vll0.facebook.com (Postfix, from userid 128203) id 9DA55B1981D4D; Tue, 12 May 2026 21:51:14 -0700 (PDT) From: Yonghong Song To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , "Jose E . Marchesi" , kernel-team@fb.com, Martin KaFai Lau Subject: [PATCH bpf-next v4 16/25] bpf: Disable private stack for x86_64 if stack arguments used Date: Tue, 12 May 2026 21:51:14 -0700 Message-ID: <20260513045114.2392291-1-yonghong.song@linux.dev> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260513044949.2382019-1-yonghong.song@linux.dev> References: <20260513044949.2382019-1-yonghong.song@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Other architectures like arm64, riscv, etc. have enough register and for them private stack can be used together with stack arguments. Signed-off-by: Yonghong Song --- kernel/bpf/verifier.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 47df3f40a71c..745e13cfb54d 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5163,7 +5163,10 @@ static int check_max_stack_depth_subprog(struct bp= f_verifier_env *env, int idx, } =20 subprog_depth =3D round_up_stack_depth(env, subprog[idx].stack_depth); - if (priv_stack_supported) { + if (IS_ENABLED(CONFIG_X86_64) && subprog[idx].stack_arg_cnt) { + /* x86-64 uses R9 for both private stack frame pointer and arg6. */ + subprog[idx].priv_stack_mode =3D NO_PRIV_STACK; + } else if (priv_stack_supported) { /* Request private stack support only if the subprog stack * depth is no less than BPF_PRIV_STACK_MIN_SIZE. This is to * avoid jit penalty if the stack usage is small. --=20 2.53.0-Meta