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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3654C433EF for ; Tue, 15 Mar 2022 09:52:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346722AbiCOJxg (ORCPT ); Tue, 15 Mar 2022 05:53:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239448AbiCOJxd (ORCPT ); Tue, 15 Mar 2022 05:53:33 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F40614F45B for ; Tue, 15 Mar 2022 02:52:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 36E5860FCA for ; Tue, 15 Mar 2022 09:52:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4EDC3C340E8; Tue, 15 Mar 2022 09:52:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1647337940; bh=xZp/eXMO91tMhDZjdCKkuGDe3fBZ3awXTZ/mm/is1j4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VcFk4SbvSawrtUW7/iWlGCUce6DYvW+PJdRjjAR9KXhybVPU2CZPbPLrRoS6KiLGb 1pru22SndePlGTlrxRA0dgMqoPqHH13CGnLUC/Elc9xG8kSj8a2lIyHi7WLCF8eMvw 58QrTH65o/Laag+EV2QLbhK1QPleKX8DASy1YYnw4nP2JHRbfLpBAG4iX4sNV5DFS6 9DcnqU9JnjPrCB3M1u+kcaFWVF0VHRXfuwAeaDckAPnLUE4EB7C7sI8HMCk4Qh7Ceb 8e279bhuwIMdbdnk5oU9w1kQKyU7c8eU7GXz81ScZTFTEYEjADaE3gHUAHbUFBqxpN gRMNrOZLaT10g== From: Masami Hiramatsu To: Steven Rostedt Cc: kbuild-all@lists.01.org, linux-kernel@vger.kernel.org, Masami Hiramatsu , Nick Desaulniers Subject: [PATCH] ARM: kprobes: Make __kretprobe_trampoline as a pure asm function Date: Tue, 15 Mar 2022 18:52:16 +0900 Message-Id: <164733793626.1008610.12121025094280924953.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220315182558.1a056d8b3975932f6589b60f@kernel.org> References: <20220315182558.1a056d8b3975932f6589b60f@kernel.org> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make __kretprobe_trampoline() as a pure asm function same as the x86 code does. Anyway, it is safe to define the symbol in the asm code instead of accessing a C symbol from the inline asm. Without this fix, building arm kernel with GCC-11 may cause below error. /tmp/ccIWiggX.s: Assembler messages: >> /tmp/ccIWiggX.s:22: Error: invalid literal constant: pool needs to be closer This fixes the error reported by 0day build bot. Reported-by: kernel test robot Fixes: 7e9bf33b8124 ("ARM: kprobes: Make a frame pointer on __kretprobe_trampoline") Signed-off-by: Masami Hiramatsu --- arch/arm/probes/kprobes/core.c | 57 +++++++++++++++++++++------------------- 1 file changed, 30 insertions(+), 27 deletions(-) diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index 4848404ba51b..51f1438456ae 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -373,43 +373,46 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, * should be enough for stacktrace from the return handler with or * without pt_regs. */ -void __naked __kprobes __kretprobe_trampoline(void) -{ - __asm__ __volatile__ ( +asm( + ".text\n" + ".global __kretprobe_trampoline\n" + ".type __kretprobe_trampoline, %function\n" + "__kretprobe_trampoline:\n" #ifdef CONFIG_FRAME_POINTER - "ldr lr, =__kretprobe_trampoline \n\t" + "ldr lr, =__kretprobe_trampoline \n\t" /* __kretprobe_trampoline makes a framepointer on pt_regs. */ #ifdef CONFIG_CC_IS_CLANG - "stmdb sp, {sp, lr, pc} \n\t" - "sub sp, sp, #12 \n\t" - /* In clang case, pt_regs->ip = lr. */ - "stmdb sp!, {r0 - r11, lr} \n\t" - /* fp points regs->r11 (fp) */ - "add fp, sp, #44 \n\t" + "stmdb sp, {sp, lr, pc} \n\t" + "sub sp, sp, #12 \n\t" + /* In clang case, pt_regs->ip = lr. */ + "stmdb sp!, {r0 - r11, lr} \n\t" + /* fp points regs->r11 (fp) */ + "add fp, sp, #44 \n\t" #else /* !CONFIG_CC_IS_CLANG */ - /* In gcc case, pt_regs->ip = fp. */ - "stmdb sp, {fp, sp, lr, pc} \n\t" - "sub sp, sp, #16 \n\t" - "stmdb sp!, {r0 - r11} \n\t" - /* fp points regs->r15 (pc) */ - "add fp, sp, #60 \n\t" + /* In gcc case, pt_regs->ip = fp. */ + "stmdb sp, {fp, sp, lr, pc} \n\t" + "sub sp, sp, #16 \n\t" + "stmdb sp!, {r0 - r11} \n\t" + /* fp points regs->r15 (pc) */ + "add fp, sp, #60 \n\t" #endif /* CONFIG_CC_IS_CLANG */ #else /* !CONFIG_FRAME_POINTER */ - "sub sp, sp, #16 \n\t" - "stmdb sp!, {r0 - r11} \n\t" + "sub sp, sp, #16 \n\t" + "stmdb sp!, {r0 - r11} \n\t" #endif /* CONFIG_FRAME_POINTER */ - "mov r0, sp \n\t" - "bl trampoline_handler \n\t" - "mov lr, r0 \n\t" - "ldmia sp!, {r0 - r11} \n\t" - "add sp, sp, #16 \n\t" + "mov r0, sp \n\t" + "bl trampoline_handler \n\t" + "mov lr, r0 \n\t" + "ldmia sp!, {r0 - r11} \n\t" + "add sp, sp, #16 \n\t" #ifdef CONFIG_THUMB2_KERNEL - "bx lr \n\t" + "bx lr \n\t" #else - "mov pc, lr \n\t" + "mov pc, lr \n\t" #endif - : : : "memory"); -} + ".size __kretprobe_trampoline, .-__kretprobe_trampoline\n" +); +NOKPROBE_SYMBOL(__kretprobe_trampoline); /* Called from __kretprobe_trampoline */ static __used __kprobes void *trampoline_handler(struct pt_regs *regs)