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[2620:137:e000::1:20]) by mx.google.com with ESMTP id b4-20020a170902d88400b00198f9ca1352si147762plz.101.2023.02.03.23.05.49; Fri, 03 Feb 2023 23:06:02 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=RCTJHj7y; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233356AbjBDHEd (ORCPT + 99 others); Sat, 4 Feb 2023 02:04:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233325AbjBDHEY (ORCPT ); Sat, 4 Feb 2023 02:04:24 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03E3D279B8; Fri, 3 Feb 2023 23:03:58 -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 9149960AF2; Sat, 4 Feb 2023 07:03:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B6C1C433D2; Sat, 4 Feb 2023 07:03:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675494237; bh=NZL7k5T/gq/CBdcI/CQC/x9NElRVpSMRhseuithZiTk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RCTJHj7yMizzNr+tIrRd44waisd2ftI36vyVF6zEwPQETa/I2Z383YVAotw9uSYU2 pXrC2GcWAYJxE61oYIkjaKnMrNgCfPdEABqMJie+I33E4k45/XOq90cnXdbwfGW5Q6 XpFWFJjyTmD+aonb4cRWwqpcDmYVvoW+ycivFjpXtMzsouEu0xIUjlanLTdsmjiwr7 F/13FHM6UZDPWvKlGKkczxDYL3cGVy4n7m5ZJ5N2lM26yiNkyn+zkPdPRALMa9y7Ym qoIrXxQwu0IGGKyVG1N444E+Y2PB0S9Y8CesKJH87XBm2QdcHkTOcoQvatU+oEhId0 ibIokDA9vw/Dw== 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, mark.rutland@arm.com, ben@decadent.org.uk, bjorn@kernel.org, miguel.ojeda.sandonis@gmail.com Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= Subject: [PATCH -next V16 6/7] riscv: entry: Consolidate ret_from_kernel_thread into ret_from_fork Date: Sat, 4 Feb 2023 02:02:12 -0500 Message-Id: <20230204070213.753369-7-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20230204070213.753369-1-guoren@kernel.org> References: <20230204070213.753369-1-guoren@kernel.org> MIME-Version: 1.0 X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1756883176550266469?= X-GMAIL-MSGID: =?utf-8?q?1756883176550266469?= 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 makes entry.S more clean. Signed-off-by: Jisheng Zhang Reviewed-by: Björn Töpel 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 bc322f92ba34..5ccef259498d 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -132,7 +132,6 @@ SYM_CODE_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) @@ -334,20 +333,15 @@ SYM_CODE_END(handle_kernel_stack_overflow) SYM_CODE_START(ret_from_fork) call schedule_tail - move a0, sp /* pt_regs */ - la ra, ret_from_exception - tail syscall_exit_to_user_mode -SYM_CODE_END(ret_from_fork) - -SYM_CODE_START(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 -SYM_CODE_END(ret_from_kernel_thread) +SYM_CODE_END(ret_from_fork) /* * Integer register context switch diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index 8955f2432c2d..46806d5d10fa 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -34,7 +34,6 @@ EXPORT_SYMBOL(__stack_chk_guard); #endif extern asmlinkage void ret_from_fork(void); -extern asmlinkage void ret_from_kernel_thread(void); void arch_cpu_idle(void) { @@ -174,7 +173,6 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) /* Supervisor/Machine, irqs on: */ childregs->status = SR_PP | SR_PIE; - p->thread.ra = (unsigned long)ret_from_kernel_thread; p->thread.s[0] = (unsigned long)args->fn; p->thread.s[1] = (unsigned long)args->fn_arg; } else { @@ -184,8 +182,9 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) if (clone_flags & CLONE_SETTLS) childregs->tp = tls; childregs->a0 = 0; /* Return value of fork() */ - p->thread.ra = (unsigned long)ret_from_fork; + p->thread.s[0] = 0; } + p->thread.ra = (unsigned long)ret_from_fork; p->thread.sp = (unsigned long)childregs; /* kernel sp */ return 0; }