From nobody Fri Sep 19 03:43:36 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 1CA7CC433FE for ; Wed, 30 Nov 2022 03:45:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233365AbiK3DpG (ORCPT ); Tue, 29 Nov 2022 22:45:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232933AbiK3DoS (ORCPT ); Tue, 29 Nov 2022 22:44:18 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 501CA95BB; Tue, 29 Nov 2022 19:43:48 -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 sin.source.kernel.org (Postfix) with ESMTPS id EBAA2CE0B8A; Wed, 30 Nov 2022 03:43:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0AEB9C433D6; Wed, 30 Nov 2022 03:43:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669779825; bh=lnoKu28Fc9fEyibwcuIO3LwBsdtybFxiOBpzcEMK9/I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C87B5dL2USumUlkcea4T+WHtUwUPBI7DadEe/HbMQYsoYp1OvMXectEjCfyMye5Hv b1nbWU0HOC9asmo32ux7z6+0tY2ETmsljMeGC0w2CgN9pJRwOtNQ3u8PDCCkJCJHy6 P0t4acjHlJFCmDQ5FGzECFV1WSuCsCNoo055gBxosGLMO6M7WEBwNWIzRhCU9x0xWk rIMheOnadphxptAm8icMZoVCXK/wYZ9pyXDXK7cmcihBZZaE/TXAI8NgbcQq2KzhBq CL8zfjOaBn8R+iVDWIRevX0avPkXdRwlYfuKJE3lYpIt0WKldxdnbGNZi7IqBZwa7q WOquzcKvYllvQ== 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 Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: [PATCH -next V9 13/14] riscv: consolidate ret_from_kernel_thread into ret_from_fork Date: Tue, 29 Nov 2022 22:40:58 -0500 Message-Id: <20221130034059.826599-14-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20221130034059.826599-1-guoren@kernel.org> References: <20221130034059.826599-1-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 b1babad5f829..d4c061f7fbfa 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 */ ENTRY(ret_from_exception) REG_L s0, PT_STATUS(sp) @@ -326,20 +325,15 @@ 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