From nobody Fri Sep 5 20:16:47 2025 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 DDA9DC32772 for ; Tue, 23 Aug 2022 11:59:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359126AbiHWL7j (ORCPT ); Tue, 23 Aug 2022 07:59:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359315AbiHWL4g (ORCPT ); Tue, 23 Aug 2022 07:56:36 -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 51AAB857E4; Tue, 23 Aug 2022 02:34:08 -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 17632612D6; Tue, 23 Aug 2022 09:34:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 069DFC433D6; Tue, 23 Aug 2022 09:34:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661247247; bh=UlzcKidXqLG4HmGSEd5gPKAWOKksFX8ym+DBmzhofjk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zt+M1/kKLzuGgz2VlKJf1CiEKPDWN5HwKUm/nMAtvU9P0k6CKmGEO5rdM2qunj3ag ZlfpbVKLsOXEouj5+rSiFp9oS2tlfF7U9/GIzzNTVlGokCrO3S3B0kv54Vqx3ibrm7 yj+A76RJhFJh8l58WE9sw1c0S7HAqr0SNpK2wvY0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Al Viro , Dinh Nguyen Subject: [PATCH 5.4 334/389] nios2: add force_successful_syscall_return() Date: Tue, 23 Aug 2022 10:26:52 +0200 Message-Id: <20220823080129.465760193@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080115.331990024@linuxfoundation.org> References: <20220823080115.331990024@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Al Viro commit fd0c153daad135d0ec1a53c5dbe6936a724d6ae1 upstream. If we use the ancient SysV syscall ABI, we'd better have tell the kernel how to claim that a negative return value is a success. Use ->orig_r2 for that - it's inaccessible via ptrace, so it's a fair game for changes and it's normally[*] non-negative on return from syscall. Set to -1; syscall is not going to be restart-worthy by definition, so we won't interfere with that use either. [*] the only exception is rt_sigreturn(), where we skip the entire messing with r1/r2 anyway. Fixes: 82ed08dd1b0e ("nios2: Exception handling") Signed-off-by: Al Viro Signed-off-by: Dinh Nguyen Signed-off-by: Greg Kroah-Hartman --- arch/nios2/include/asm/ptrace.h | 2 ++ arch/nios2/kernel/entry.S | 6 ++++++ 2 files changed, 8 insertions(+) --- a/arch/nios2/include/asm/ptrace.h +++ b/arch/nios2/include/asm/ptrace.h @@ -74,6 +74,8 @@ extern void show_regs(struct pt_regs *); ((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE)\ - 1) =20 +#define force_successful_syscall_return() (current_pt_regs()->orig_r2 =3D = -1) + int do_syscall_trace_enter(void); void do_syscall_trace_exit(void); #endif /* __ASSEMBLY__ */ --- a/arch/nios2/kernel/entry.S +++ b/arch/nios2/kernel/entry.S @@ -213,6 +213,9 @@ local_restart: translate_rc_and_ret: movi r1, 0 bge r2, zero, 3f + ldw r1, PT_ORIG_R2(sp) + addi r1, r1, 1 + beq r1, zero, 3f sub r2, zero, r2 movi r1, 1 3: @@ -276,6 +279,9 @@ traced_system_call: translate_rc_and_ret2: movi r1, 0 bge r2, zero, 4f + ldw r1, PT_ORIG_R2(sp) + addi r1, r1, 1 + beq r1, zero, 4f sub r2, zero, r2 movi r1, 1 4: