From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E0DC3C433F5 for ; Wed, 27 Apr 2022 17:45:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=RrB9B0Onr4EgX1UE8zJ1qJcsOsejiAy/gBuO9OlBP8s=; b=s2+LI4gEQVZn1v Tdq6Tq7xS9O92vLfPxCTyNckki/VVijWNE+irVYX92puwPR26O5HyEABflxGooMtL3iruw3JKm7FL Y223Mi7L5aI09oZPic+cS9QqMqLeotOhshT2Twz/tWiEkFmZrkLoslB3QHvw+a4yKHLCBWrk53BCB IShFyOVCZiZ4dZb66DOP60hQjMqIIEl8Jnd36bJxqw1CIAmwf0huoqGt0+FQ/Hwz/S3e1j0AiO+Qq 3QX619xTy933ZlciRR4qPZ15QEvHARzyU2/Ei3u5UbaKF2oKq39XJ7Sk3dSHZyZd624Xiw+87uQro Uip6Ls99oF/KNrJYLQEg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1njliT-002l9g-AH; Wed, 27 Apr 2022 17:44:41 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1njlW2-002gX4-LT for linux-arm-kernel@lists.infradead.org; Wed, 27 Apr 2022 17:31:52 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3145DED1; Wed, 27 Apr 2022 10:31:50 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id F0BBE3F73B; Wed, 27 Apr 2022 10:31:48 -0700 (PDT) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Cc: akpm@linux-foundation.org, alex.popov@linux.com, catalin.marinas@arm.com, keescook@chromium.org, linux-kernel@vger.kernel.org, luto@kernel.org, mark.rutland@arm.com, will@kernel.org Subject: [PATCH v2 08/13] lkdtm/stackleak: avoid spurious failure Date: Wed, 27 Apr 2022 18:31:23 +0100 Message-Id: <20220427173128.2603085-9-mark.rutland@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220427173128.2603085-1-mark.rutland@arm.com> References: <20220427173128.2603085-1-mark.rutland@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220427_103150_782187_5F98117D X-CRM114-Status: GOOD ( 13.21 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The lkdtm_STACKLEAK_ERASING() test scans for a contiguous block of poison values between the low stack bound and the stack pointer, and fails if it does not find a sufficiently large block. This can happen legitimately if the scan the low stack bound, which could occur if functions called prior to lkdtm_STACKLEAK_ERASING() used a large amount of stack. If this were to occur, it means that the erased portion of the stack is smaller than the size used by the scan, but does not cause a functional problem In practice this is unlikely to happen, but as this is legitimate and would not result in a functional problem, the test should not fail in this case. Remove the spurious failure case. Signed-off-by: Mark Rutland Cc: Alexander Popov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Kees Cook --- drivers/misc/lkdtm/stackleak.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/misc/lkdtm/stackleak.c b/drivers/misc/lkdtm/stackleak.c index 00db21ff115e4..707d530d509b7 100644 --- a/drivers/misc/lkdtm/stackleak.c +++ b/drivers/misc/lkdtm/stackleak.c @@ -53,13 +53,6 @@ void lkdtm_STACKLEAK_ERASING(void) found = 0; } - if (found <= check_depth) { - pr_err("FAIL: the erased part is not found (checked %lu bytes)\n", - i * sizeof(unsigned long)); - test_failed = true; - goto end; - } - pr_info("the erased part begins after %lu not poisoned bytes\n", (i - found) * sizeof(unsigned long)); -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel