From nobody Sat Oct 11 12:06:57 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9377328AAFF; Tue, 10 Jun 2025 09:24:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749547457; cv=none; b=Nu45fNTgMlJKz8SWGM5YQDEorxmSDJe85Gp2RIBEmEE7bBS1jVijT+qY5OmyVXArccK1Kw/+ebV+IqlP78IL/tIFJz1MPu64NJUH3IR0aLnTuj+mNmG+pV7Y2267e70G6SXQsEa+Dg0eTfZVgo3Hp8vfIR6I/AvuJY1vwHNZLBE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749547457; c=relaxed/simple; bh=DXnxrZCKNCbvmNqckFGO7yqFhyxX1F28F7u/tRCZUCE=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=uYtLoizyRl29dfPaBdxDJAKjJ+qPRhiVAckaUWzACHcxhPzVvLfKz6zZrAReWxt2Sr9fhW6xSSYiWFZx9QCRMDguybbwSX06qBIwFpD45tUkuMk7NDkzRuFd26obSgBzNQAiQnCZ7ncqMWl7g5M4Ri3Q5djEoWnTs6D1Ej5G9nY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AEbp9dZb; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AEbp9dZb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84E2CC4CEED; Tue, 10 Jun 2025 09:24:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749547457; bh=DXnxrZCKNCbvmNqckFGO7yqFhyxX1F28F7u/tRCZUCE=; h=From:To:Cc:Subject:Date:From; b=AEbp9dZb8IWFBmoWA6giJjGXvzs6CbRsjZgQLpkdE8IPFTQVz0FrKmTcxgy8zJRWU RxVoLyzDomXui+aiFcLNAk8mF8CERJInhxrjUDzD+n48BOHc/R3K1C9nEzW4X4lUxU h6oHu/UGRrHM+IMhc76VEWsCWny3x78WIeu68Lmt5myp9BW7RV6TPhpYl/QUnFk2Pp XfvsRm3ZjFxC4766MQMfcA72mcl9Bqq0nk+VGuzIsdSSFzC0tZEndwf9jDagI5htMd Pzw4oiolaYx97vLFS5yRuS03pygMuTFWPjKiWOjde6SPW5xGwjYL050jT0ZqtnvWYE Kxl+zacuaxp/Q== From: Arnd Bergmann To: Kent Overstreet , Nathan Chancellor Cc: Arnd Bergmann , Nick Desaulniers , Bill Wendling , Justin Stitt , Thomas Bertschinger , linux-bcachefs@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH] bcachefs: ioctl: avoid stack overflow warning Date: Tue, 10 Jun 2025 11:24:04 +0200 Message-Id: <20250610092413.2640349-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Arnd Bergmann Multiple ioctl handlers individually use a lot of stack space, and clang ch= ooses to inline them into the bch2_fs_ioctl() function, blowing through the warni= ng limit: fs/bcachefs/chardev.c:655:6: error: stack frame size (1032) exceeds limit (= 1024) in 'bch2_fs_ioctl' [-Werror,-Wframe-larger-than] 655 | long bch2_fs_ioctl(struct bch_fs *c, unsigned cmd, void __user *arg) By marking the largest two of them as noinline_for_stack, no indidual code = path ends up using this much, which avoids the warning and reduces the possible total stack usage in the ioctl handler. Signed-off-by: Arnd Bergmann --- fs/bcachefs/chardev.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/bcachefs/chardev.c b/fs/bcachefs/chardev.c index 2d38466eddfd..fde3c2380e28 100644 --- a/fs/bcachefs/chardev.c +++ b/fs/bcachefs/chardev.c @@ -399,7 +399,7 @@ static long bch2_ioctl_data(struct bch_fs *c, return ret; } =20 -static long bch2_ioctl_fs_usage(struct bch_fs *c, +static noinline_for_stack long bch2_ioctl_fs_usage(struct bch_fs *c, struct bch_ioctl_fs_usage __user *user_arg) { struct bch_ioctl_fs_usage arg =3D {}; @@ -469,7 +469,7 @@ static long bch2_ioctl_query_accounting(struct bch_fs *= c, } =20 /* obsolete, didn't allow for new data types: */ -static long bch2_ioctl_dev_usage(struct bch_fs *c, +static noinline_for_stack long bch2_ioctl_dev_usage(struct bch_fs *c, struct bch_ioctl_dev_usage __user *user_arg) { struct bch_ioctl_dev_usage arg; --=20 2.39.5