From nobody Sat Feb 7 20:38:40 2026 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 E4A93C32771 for ; Wed, 28 Sep 2022 16:30:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230063AbiI1QaO (ORCPT ); Wed, 28 Sep 2022 12:30:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39252 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229940AbiI1Q3o (ORCPT ); Wed, 28 Sep 2022 12:29:44 -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 73F6462F7 for ; Wed, 28 Sep 2022 09:29:42 -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 5D90261F30 for ; Wed, 28 Sep 2022 16:29:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4BDEC43141; Wed, 28 Sep 2022 16:29:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664382580; bh=ddcSdAqJtV7YjhFUF+/+mxLRCnz8byHozG9Vd7pQWN4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L0yMrfgpP/2Wki358yrQPk1PxJHQLaBxbk+n47BfB27WnVmsqgC3/CaeoNc+bLY+1 ZdfkPb6x80BIld7W2UThJT6FSnlg/loBoZt7bXM68ftsUzhGNHJWdnCOdXE1R5F9Ao zmhIP1O78RhuJ2UxlUV3J/viOaeh/sOkVyZ/XEQwt/4tqO9F0oCLttRrvGiAYpk/Ji iLRllCWwUZX/hmm7k2ig29XvO9RPwSv2OJ4MzpddQcI77zkSZbqlrxbQud/sNfZr/h 0v1WYIBbLG0+CJ3TKV2bS6wqbtkHb8i3nJXYhwxCUG2levbRMH0TIBCO+sr9/ObtYS go3GpoUmDwFnQ== From: Jisheng Zhang To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Nathan Chancellor , Nick Desaulniers , Guo Ren Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH v2 2/4] riscv: consolidate ret_from_kernel_thread into ret_from_fork Date: Thu, 29 Sep 2022 00:20:05 +0800 Message-Id: <20220928162007.3791-3-jszhang@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220928162007.3791-1-jszhang@kernel.org> References: <20220928162007.3791-1-jszhang@kernel.org> 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" The ret_from_kernel_thread() behaves similarly with ret_from_fork(), the only difference is whether call the fn(arg) or not, this can be acchieved by testing fn is NULL or not, I.E s0 is 0 or not. Signed-off-by: Jisheng Zhang --- arch/riscv/kernel/entry.S | 11 +++-------- arch/riscv/kernel/process.c | 5 ++--- 2 files changed, 5 insertions(+), 11 deletions(-) diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 2207cf44a3bc..a3e1ed2fa2ac 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -323,20 +323,15 @@ END(handle_kernel_stack_overflow) =20 ENTRY(ret_from_fork) call schedule_tail - move a0, sp /* pt_regs */ - la ra, ret_from_exception - tail syscall_exit_to_user_mode -ENDPROC(ret_from_fork) - -ENTRY(ret_from_kernel_thread) - call schedule_tail + beqz s0, 1f /* not from kernel thread */ /* Call fn(arg) */ move a0, s1 jalr s0 +1: move a0, sp /* pt_regs */ la ra, ret_from_exception tail syscall_exit_to_user_mode -ENDPROC(ret_from_kernel_thread) +ENDPROC(ret_from_fork) =20 #ifdef CONFIG_IRQ_STACKS ENTRY(call_on_stack) diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index ceb9ebab6558..67e7cd123ceb 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -34,7 +34,6 @@ EXPORT_SYMBOL(__stack_chk_guard); #endif =20 extern asmlinkage void ret_from_fork(void); -extern asmlinkage void ret_from_kernel_thread(void); =20 void arch_cpu_idle(void) { @@ -172,7 +171,6 @@ int copy_thread(struct task_struct *p, const struct ker= nel_clone_args *args) /* Supervisor/Machine, irqs on: */ childregs->status =3D SR_PP | SR_PIE; =20 - p->thread.ra =3D (unsigned long)ret_from_kernel_thread; p->thread.s[0] =3D (unsigned long)args->fn; p->thread.s[1] =3D (unsigned long)args->fn_arg; } else { @@ -182,8 +180,9 @@ int copy_thread(struct task_struct *p, const struct ker= nel_clone_args *args) if (clone_flags & CLONE_SETTLS) childregs->tp =3D tls; childregs->a0 =3D 0; /* Return value of fork() */ - p->thread.ra =3D (unsigned long)ret_from_fork; + p->thread.s[0] =3D 0; } + p->thread.ra =3D (unsigned long)ret_from_fork; p->thread.sp =3D (unsigned long)childregs; /* kernel sp */ return 0; } --=20 2.34.1