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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2DCAC433F5 for ; Tue, 9 Nov 2021 16:49:43 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id A95F1610CF for ; Tue, 9 Nov 2021 16:49:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org A95F1610CF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org 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=EeIi59wuLcOaIFU7dkC0NTWvTcDnjjm17+aY3ftQUjY=; b=TXOJbuttrU0vI9 LpS9cqiSyS1avbQDXq29ttNHGwhlJ3Ewqf4lKyoaQ9Bo0H1VXNkoN4tGD0Fur2Fali+i2oySrfz6z Z0e++0WV/2qg4/WSMYQTbSoDR/V4z2rdWcUSEMGatOIWisYdiOddmkb8Gb4w853DqYbLJDh5r+JdG ZVdur4R34RAiw4UKqK0gPE5VuA6N3oCbOJc8K0VOsiBLvFAaPUb4OFSrbPQqlJAaJ9IqV0McpSIoE 3X1J4NOvQ+8GnNjbYz0Ej7mw3TV7K+Yqpj+SdnTGVXD93bD2IK3ntuhN1Edf7V40pWmYFPFYLcqOI zI7Ke8gmKItMRfsM3Lrg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mkUIA-002k4z-83; Tue, 09 Nov 2021 16:48:15 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mkUGK-002jAc-IX for linux-arm-kernel@lists.infradead.org; Tue, 09 Nov 2021 16:46:22 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 77B5361208; Tue, 9 Nov 2021 16:46:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636476380; bh=y4wX9s7+HTFSjvSFbSz19j1vGuRP1pTMfkmfOmSDxk0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K2HMR0HhOmDIjnKehI2zVcTXPq9wGyta0DEKpQg2jTiHG7jhmALFUsLkzG08xldsA wlo+v7aGh7S5m0+NIUatxOL3oigNXbkSK9UbDbZ0fC29FYujAGOWXta3q2Ln87m5sK TjgZnVTKb+MRpDVnhqAz7xrCKyE9ty+/9J7WEFLfiHEShFXsXGqo0ho41zIj4lvdZ5 LBbtzM8HnhgCk7aT6cLYhT8rSy+batd5g11u/dmBVx8Vk9Q+4u/m6EDttdcoVXFVFY bi4K/tcPEx/2fxY2rtuSB6IrUiRocgtULA7Wjw/+ZdWm0vAzBYcE9QfGVyxcbEetFM r0n//gdXyinoA== From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Ard Biesheuvel , Peter Zijlstra , Josh Poimboeuf , Jason Baron , Steven Rostedt , Mark Rutland , Kees Cook Subject: [RFC PATCH 5/7] static_call: use non-function types to refer to the trampolines Date: Tue, 9 Nov 2021 17:45:47 +0100 Message-Id: <20211109164549.1724710-6-ardb@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211109164549.1724710-1-ardb@kernel.org> References: <20211109164549.1724710-1-ardb@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3650; h=from:subject; bh=y4wX9s7+HTFSjvSFbSz19j1vGuRP1pTMfkmfOmSDxk0=; b=owEB7QES/pANAwAKAcNPIjmS2Y8kAcsmYgBhiqW4kuuGzSKDlkzz0Prr9jyqVx4AQlIlqxGFdRli /7KncCGJAbMEAAEKAB0WIQT72WJ8QGnJQhU3VynDTyI5ktmPJAUCYYqluAAKCRDDTyI5ktmPJE3UC/ 4p0HTDMxRSJjJf/8PM0gRDp1+LIR1qeOeEhRxErabIqKkFs93BL+JUNgdDqFVDedZnHVP06Gw7zFZl gH4Kb9cn5wVIkLg+3UnZf1hHAu9r0cDk+jZHWlqY1Z4jVIYWBY6eKqZ5icgGd45gWeMSubeBJ7zcex RZCgqSdFvzhmRBnB9X5s+Rkv9EMuDtwQGYUPdHlh+ezQu9fQTo0H31kdlesKhqeXM8cY+fr9rYcPPx CGdv/TXZQJjoQyoB6Ldua6xst+ruUyuQT20FPD5v8s9536+0r148lSCGXlFQPGgpjd87c1TTf0Y+L3 +01rsbJAGslVw6m89pEQ6HsIgyUY5M89x77pYZLoi6UwrFK5L+VIqQLkUaI7QuD9+fRp3AfCMlTGro jjhjuHPikYB7skd5HoKLkjJAbpu9y9KWX/La123QpTghAuZ1eL1F9cT9e1W7rmX6t0hQQ6ukzQqus5 gMy0TLikfsxKQ9Lo8XvdyZStVt6eGnpmE+J0dMTJDh3H4= X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211109_084620_720382_16DB28D4 X-CRM114-Status: GOOD ( 13.63 ) 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 In order to prevent CFI enabled code from grabbing a jump table entry that jumps to the trampoline, rather than the trampoline itself, use an incomplete non-function type for the trampoline, and cast it to the right type only when invoking it. Acked-by: Peter Zijlstra Signed-off-by: Ard Biesheuvel --- include/linux/static_call.h | 2 +- include/linux/static_call_types.h | 6 +++--- tools/include/linux/static_call_types.h | 6 +++--- 3 files changed, 7 insertions(+), 7 deletions(-) diff --git a/include/linux/static_call.h b/include/linux/static_call.h index 391f737496eb..6b261fe96ba3 100644 --- a/include/linux/static_call.h +++ b/include/linux/static_call.h @@ -144,7 +144,7 @@ extern void arch_static_call_transform(void *site, void *tramp, void *func, bool #define static_call_update(name, func) \ ({ \ - typeof(&STATIC_CALL_TRAMP(name)) __F = (func); \ + typeof(STATIC_CALL_QUERY(name)()) __F = (func); \ __static_call_update(&STATIC_CALL_KEY(name), \ STATIC_CALL_TRAMP_ADDR(name), __F); \ }) diff --git a/include/linux/static_call_types.h b/include/linux/static_call_types.h index 2fce9aa8a995..eae11c5b015d 100644 --- a/include/linux/static_call_types.h +++ b/include/linux/static_call_types.h @@ -47,7 +47,7 @@ struct static_call_site { extern __weak struct static_call_key STATIC_CALL_KEY(name); \ extern __weak struct static_call_key *STATIC_CALL_GETKEY(name)(void);\ extern __weak typeof(func) *STATIC_CALL_QUERY(name)(void); \ - extern typeof(func) STATIC_CALL_TRAMP(name) + extern struct static_call_tramp STATIC_CALL_TRAMP(name) #define __static_call_query(name) \ ((typeof(STATIC_CALL_QUERY(name)()))READ_ONCE(STATIC_CALL_KEY(name).func)) @@ -66,7 +66,7 @@ struct static_call_site { #define static_call(name) \ ({ \ __STATIC_CALL_ADDRESSABLE(name); \ - (&STATIC_CALL_TRAMP(name)); \ + ((typeof(STATIC_CALL_QUERY(name)()))&STATIC_CALL_TRAMP(name)); \ }) #ifdef CONFIG_HAVE_STATIC_CALL_INLINE @@ -107,7 +107,7 @@ struct static_call_key { }; #define static_call(name) \ - ((typeof(STATIC_CALL_TRAMP(name))*)(STATIC_CALL_KEY(name).func)) + ((typeof(STATIC_CALL_QUERY(name)()))(STATIC_CALL_KEY(name).func)) #endif /* CONFIG_HAVE_STATIC_CALL */ diff --git a/tools/include/linux/static_call_types.h b/tools/include/linux/static_call_types.h index 2fce9aa8a995..eae11c5b015d 100644 --- a/tools/include/linux/static_call_types.h +++ b/tools/include/linux/static_call_types.h @@ -47,7 +47,7 @@ struct static_call_site { extern __weak struct static_call_key STATIC_CALL_KEY(name); \ extern __weak struct static_call_key *STATIC_CALL_GETKEY(name)(void);\ extern __weak typeof(func) *STATIC_CALL_QUERY(name)(void); \ - extern typeof(func) STATIC_CALL_TRAMP(name) + extern struct static_call_tramp STATIC_CALL_TRAMP(name) #define __static_call_query(name) \ ((typeof(STATIC_CALL_QUERY(name)()))READ_ONCE(STATIC_CALL_KEY(name).func)) @@ -66,7 +66,7 @@ struct static_call_site { #define static_call(name) \ ({ \ __STATIC_CALL_ADDRESSABLE(name); \ - (&STATIC_CALL_TRAMP(name)); \ + ((typeof(STATIC_CALL_QUERY(name)()))&STATIC_CALL_TRAMP(name)); \ }) #ifdef CONFIG_HAVE_STATIC_CALL_INLINE @@ -107,7 +107,7 @@ struct static_call_key { }; #define static_call(name) \ - ((typeof(STATIC_CALL_TRAMP(name))*)(STATIC_CALL_KEY(name).func)) + ((typeof(STATIC_CALL_QUERY(name)()))(STATIC_CALL_KEY(name).func)) #endif /* CONFIG_HAVE_STATIC_CALL */ -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel