From nobody Thu Sep 18 09:55:21 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 22F72C4708E for ; Thu, 8 Dec 2022 03:00:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229950AbiLHDAF (ORCPT ); Wed, 7 Dec 2022 22:00:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46876 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229948AbiLHC7b (ORCPT ); Wed, 7 Dec 2022 21:59:31 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AA9C4B9A0; Wed, 7 Dec 2022 18:59:31 -0800 (PST) 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 0188D61D42; Thu, 8 Dec 2022 02:59:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C953EC433B5; Thu, 8 Dec 2022 02:59:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1670468370; bh=rRgx4hNzhe0jjK9q+Rvjiqoqgz/4yVh97abPr6C0y4s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jfGYxeCZcHz+CEeLuNUPorKvKFANyfkrnUHsztgFIv+ODD3Ic3uLcl6rcuaB/K5pl pdeOeA8EAoTSnzrBOhse/OKdfcLhKvgbGM8hX9IC4IfNATSrJL7thnOenc4F23JmhD mFFUIyU8rP4sdn3YVgY9xJuLUWuEGLvsphUG7tuWSEtScxF0JcOESJi7twqFf0l05B vUHQ+miEFAwt5k66tDYivwmeBqZsVXwbtPU7V1tP+XL7huFkidYCTenmaE5NrWcNNN mKARQcbG8eIjS5fBnxLG2qVRp6Jmne3cbrxQXvZaIffseEohDrPMzkcgMlM6BXro3a 1RvPCxFrhh4lg== From: guoren@kernel.org To: arnd@arndb.de, guoren@kernel.org, palmer@rivosinc.com, tglx@linutronix.de, peterz@infradead.org, luto@kernel.org, conor.dooley@microchip.com, heiko@sntech.de, jszhang@kernel.org, lazyparser@gmail.com, falcon@tinylab.org, chenhuacai@kernel.org, apatel@ventanamicro.com, atishp@atishpatra.org, palmer@dabbelt.com, paul.walmsley@sifive.com, mark.rutland@arm.com, zouyipeng@huawei.com, bigeasy@linutronix.de, David.Laight@aculab.com, chenzhongjin@huawei.com, greentime.hu@sifive.com, andy.chiu@sifive.com, ben@decadent.org.uk, bjorn@kernel.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: [PATCH -next V10 06/10] riscv: entry: Consolidate ret_from_kernel_thread into ret_from_fork Date: Wed, 7 Dec 2022 21:58:12 -0500 Message-Id: <20221208025816.138712-7-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20221208025816.138712-1-guoren@kernel.org> References: <20221208025816.138712-1-guoren@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" From: Jisheng Zhang 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 achieved by testing fn is NULL or not, I.E s0 is 0 or not. Many architectures have done the same thing, it make entry.S more clean. Signed-off-by: Jisheng Zhang Reviewed-by: Guo Ren Tested-by: Guo Ren Signed-off-by: Guo Ren --- arch/riscv/kernel/entry.S | 12 +++--------- arch/riscv/kernel/process.c | 5 ++--- 2 files changed, 5 insertions(+), 12 deletions(-) diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 69097dfffdc9..e4a9140a5b99 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -132,7 +132,6 @@ END(handle_exception) * caller list: * - handle_exception * - ret_from_fork - * - ret_from_kernel_thread */ SYM_CODE_START_NOALIGN(ret_from_exception) REG_L s0, PT_STATUS(sp) @@ -323,20 +322,15 @@ 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 =20 /* diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index b0c63e8e867e..5108c76a14dd 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 2.36.1