From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from www62.your-server.de (www62.your-server.de [213.133.104.62]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5A7BB144D13 for ; Thu, 13 Jun 2024 11:53:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.133.104.62 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718279606; cv=none; b=ZCY+kuW+4YkoNp65ObAZx283l+g8CUtDlCJRqB1BZd+V12E5zHcy4hGE3W46/2TP0V7bGP/nqzP6DHiDWjdiuFupiBdkxJmzfE42+Mx8wITtwRJV6jHHdf/4dDmHDt/AFIAPUp0zRvm/LIo/kFlDJ5w9r+56F2phITk8gbw0d8M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718279606; c=relaxed/simple; bh=lsx4ZQR9c13NLDr5rFo5a4uYKtnINLXrbRGOVrupKes=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=pEDqyHduPY9+mMbLPBUVHBP5TwWuJhP7MyNskAboKd6wKHBksUNagCgJHHdZ0jqUf+FX9CHD76k5Or13ICd1AiIe6EPmkQFi/lpHArfvZ/2uXxtaYAzsrlutmQjuB8uSo4FARwBmi9WB8dReQdegVbv+f4QhvuBjolm414mjVVI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=iogearbox.net; spf=pass smtp.mailfrom=iogearbox.net; dkim=pass (2048-bit key) header.d=iogearbox.net header.i=@iogearbox.net header.b=g7/atvju; arc=none smtp.client-ip=213.133.104.62 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=iogearbox.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iogearbox.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=iogearbox.net header.i=@iogearbox.net header.b="g7/atvju" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=iogearbox.net; s=default2302; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID; bh=s+RvXUzCEtpLNZclqRnGtbwf2eq7+spSVb/AWgrahz4=; b=g7/atvjuvvyUWz3fs56wgCXa8V hb8c9HUnfKoNCsgBbUpqnokaAIM6cFsX6xfdg4J/4AFb4h4NnenBZKLqymgVxaJVlvGSuXTdmdCQ5 L6nxq9TLGHMpauo9NbxLYt1Z3dHNrWOUTQbKTatZ3jlKm49m1/EWMRydwr3FO/0tyyj5RU4pifaWW T6eOCT8BWFYyEtE/JQqx2qkMHs8ookBvJZ8gBMTtsp8j5pTbx0MY4a8Kl13Y0VgEKDyQQQsxGhqjd Kb+3H3IXNqvC6dVC9oTfWYLh7vPuBm8S4ioXxonQCWRnI9VN5iVcBYMTMovJO1VaNEcA/XxKW6zUp QCSHFiPw==; Received: from 34.249.197.178.dynamic.cust.swisscom.net ([178.197.249.34] helo=localhost) by www62.your-server.de with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sHj17-000G9k-DH; Thu, 13 Jun 2024 13:53:21 +0200 From: Daniel Borkmann To: bpf@vger.kernel.org Cc: alexei.starovoitov@gmail.com, jjlopezjaimez@google.com, andrii.nakryiko@gmail.com, eddyz87@gmail.com, john.fastabend@gmail.com, Daniel Borkmann Subject: [PATCH bpf v2 2/3] bpf: Reduce stack consumption in check_stack_write_fixed_off Date: Thu, 13 Jun 2024 13:53:09 +0200 Message-Id: <20240613115310.25383-2-daniel@iogearbox.net> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20240613115310.25383-1-daniel@iogearbox.net> References: <20240613115310.25383-1-daniel@iogearbox.net> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.103.10/27305/Thu Jun 13 10:33:25 2024) The fake_reg moved into env->fake_reg given it consumes a lot of stack space (120 bytes). Migrate the fake_reg in check_stack_write_fixed_off() as well now that we have it. Signed-off-by: Daniel Borkmann --- kernel/bpf/verifier.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index f455548ba46c..e5a0ba3bc38d 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4549,11 +4549,12 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env, state->stack[spi].spilled_ptr.id = 0; } else if (!reg && !(off % BPF_REG_SIZE) && is_bpf_st_mem(insn) && env->bpf_capable) { - struct bpf_reg_state fake_reg = {}; + struct bpf_reg_state *tmp_reg = &env->fake_reg[0]; - __mark_reg_known(&fake_reg, insn->imm); - fake_reg.type = SCALAR_VALUE; - save_register_state(env, state, spi, &fake_reg, size); + memset(tmp_reg, 0, sizeof(*tmp_reg)); + __mark_reg_known(tmp_reg, insn->imm); + tmp_reg->type = SCALAR_VALUE; + save_register_state(env, state, spi, tmp_reg, size); } else if (reg && is_spillable_regtype(reg->type)) { /* register containing pointer is being spilled into stack */ if (size != BPF_REG_SIZE) { -- 2.43.0