From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A9113FE4 for ; Sun, 25 Sep 2022 18:03:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E46D1C43470; Sun, 25 Sep 2022 18:03:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664129008; bh=ddcSdAqJtV7YjhFUF+/+mxLRCnz8byHozG9Vd7pQWN4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uPZ1E8DHuHhbUNHTWVcyF1GXeoQlnguKEFepbG3Jmh09T90BgMk5TYQonZPfLZX2+ H7FBmofZplUYBplaKlmxuksgBdwSw6xIdIwdyDnAYXR3RQb7N2EsIKd28eUhbcfyPy v1BsPTOMJtw0cXFUvT4Xs33e/2UBYSBlP+Q64dsnhRX9XMmwY9qM4tz6bf/3Y7nUsH 1zRg6BFLnsnhzbTaKsR+BuwZ4sA7FeiOXKI3ylvqGnx9uFtNOQ18QKRKujsJn09uxu FXmlkZeDpdtOU5T993HA3V6nBQQNekA7QzBlXK2SNblZDtXi/UnXEFzRz6B94KqR3z p0Ph3iieWHktA== From: Jisheng Zhang To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Guo Ren , Nathan Chancellor , Nick Desaulniers Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH 2/4] riscv: consolidate ret_from_kernel_thread into ret_from_fork Date: Mon, 26 Sep 2022 01:53:54 +0800 Message-Id: <20220925175356.681-3-jszhang@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220925175356.681-1-jszhang@kernel.org> References: <20220925175356.681-1-jszhang@kernel.org> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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) 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) #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 extern asmlinkage void ret_from_fork(void); -extern asmlinkage void ret_from_kernel_thread(void); void arch_cpu_idle(void) { @@ -172,7 +171,6 @@ 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 { @@ -182,8 +180,9 @@ 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; } -- 2.34.1