From patchwork Mon Nov 8 03:08:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: gaosong X-Patchwork-Id: 12607583 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03BBDC433F5 for ; Mon, 8 Nov 2021 03:33:51 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8AEF6610F7 for ; Mon, 8 Nov 2021 03:33:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 8AEF6610F7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from [::1] (port=51816 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mjvPp-0006d8-IC for qemu-devel@archiver.kernel.org; Sun, 07 Nov 2021 22:33:49 -0500 Received: from eggs.gnu.org ([209.51.188.92]:41316) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mjv8D-0006hy-O3 for qemu-devel@nongnu.org; Sun, 07 Nov 2021 22:15:37 -0500 Received: from mail.loongson.cn ([114.242.206.163]:56804 helo=loongson.cn) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mjv8B-0005c5-JK for qemu-devel@nongnu.org; Sun, 07 Nov 2021 22:15:37 -0500 Received: from kvm-dev1.localdomain (unknown [10.2.5.134]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9CxGdGflIhh9g8BAA--.2390S29; Mon, 08 Nov 2021 11:09:09 +0800 (CST) From: Song Gao To: qemu-devel@nongnu.org Subject: [RESEND PATCH v9 27/28] linux-user: Add safe syscall handling for loongarch64 hosts Date: Mon, 8 Nov 2021 11:08:14 +0800 Message-Id: <1636340895-5255-28-git-send-email-gaosong@loongson.cn> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1636340895-5255-1-git-send-email-gaosong@loongson.cn> References: <1636340895-5255-1-git-send-email-gaosong@loongson.cn> X-CM-TRANSID: AQAAf9CxGdGflIhh9g8BAA--.2390S29 X-Coremail-Antispam: 1UD129KBjvJXoWxWr13CrWUGFWfCr4fAr48tFb_yoWruw1rp3 WfCw15Kr48GFn7Cr9rXw4jgFyfZr4rJryYkFWSvrZYyrsrJr9Yqr1qga4vyF13CrnrKFWj vF40y3y5CF4UWaUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnUUvcSsGvfC2KfnxnUUI43ZEXa7xR_UUUUUUUUU== X-CM-SenderInfo: 5jdr20tqj6z05rqj20fqof0/ Received-SPF: pass client-ip=114.242.206.163; envelope-from=gaosong@loongson.cn; helo=loongson.cn X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: WANG Xuerui , Xiaojuan Yang Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: WANG Xuerui Signed-off-by: WANG Xuerui Reviewed-by: Richard Henderson Message-Id: <20210925173032.2434906-29-git@xen0n.name> Signed-off-by: Song Gao Signed-off-by: Xiaojuan Yang --- linux-user/host/loongarch64/hostdep.h | 32 +++++++++++ linux-user/host/loongarch64/safe-syscall.inc.S | 78 ++++++++++++++++++++++++++ 2 files changed, 110 insertions(+) create mode 100644 linux-user/host/loongarch64/hostdep.h create mode 100644 linux-user/host/loongarch64/safe-syscall.inc.S diff --git a/linux-user/host/loongarch64/hostdep.h b/linux-user/host/loongarch64/hostdep.h new file mode 100644 index 0000000..e67ecad --- /dev/null +++ b/linux-user/host/loongarch64/hostdep.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Things which are dependent on the host architecture + */ + +#ifndef LOONGARCH64_HOSTDEP_H +#define LOONGARCH64_HOSTDEP_H + +/* We have a safe-syscall.inc.S */ +#define HAVE_SAFE_SYSCALL + +#ifndef __ASSEMBLER__ + +/* These are defined by the safe-syscall.inc.S file */ +extern char safe_syscall_start[]; +extern char safe_syscall_end[]; + +/* Adjust the signal context to rewind out of safe-syscall if we're in it */ +static inline void rewind_if_in_safe_syscall(void *puc) +{ + ucontext_t *uc = puc; + unsigned long long *pcreg = &uc->uc_mcontext.__pc; + + if (*pcreg > (uintptr_t)safe_syscall_start + && *pcreg < (uintptr_t)safe_syscall_end) { + *pcreg = (uintptr_t)safe_syscall_start; + } +} + +#endif /* __ASSEMBLER__ */ + +#endif diff --git a/linux-user/host/loongarch64/safe-syscall.inc.S b/linux-user/host/loongarch64/safe-syscall.inc.S new file mode 100644 index 0000000..6220dde --- /dev/null +++ b/linux-user/host/loongarch64/safe-syscall.inc.S @@ -0,0 +1,78 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * safe-syscall.inc.S : host-specific assembly fragment + * to handle signals occurring at the same time as system calls. + * This is intended to be included by linux-user/safe-syscall.S + * + * Ported to LoongArch by WANG Xuerui + * + * Based on safe-syscall.inc.S code for every other architecture, + * originally written by Richard Henderson + * Copyright (C) 2018 Linaro, Inc. + */ + + .global safe_syscall_base + .global safe_syscall_start + .global safe_syscall_end + .type safe_syscall_base, @function + .type safe_syscall_start, @function + .type safe_syscall_end, @function + + /* + * This is the entry point for making a system call. The calling + * convention here is that of a C varargs function with the + * first argument an 'int *' to the signal_pending flag, the + * second one the system call number (as a 'long'), and all further + * arguments being syscall arguments (also 'long'). + * We return a long which is the syscall's return value, which + * may be negative-errno on failure. Conversion to the + * -1-and-errno-set convention is done by the calling wrapper. + */ +safe_syscall_base: + .cfi_startproc + /* + * The syscall calling convention is nearly the same as C: + * we enter with a0 == *signal_pending + * a1 == syscall number + * a2 ... a7 == syscall arguments + * and return the result in a0 + * and the syscall instruction needs + * a7 == syscall number + * a0 ... a5 == syscall arguments + * and returns the result in a0 + * Shuffle everything around appropriately. + */ + move $t0, $a0 /* signal_pending pointer */ + move $t1, $a1 /* syscall number */ + move $a0, $a2 /* syscall arguments */ + move $a1, $a3 + move $a2, $a4 + move $a3, $a5 + move $a4, $a6 + move $a5, $a7 + move $a7, $t1 + + /* + * This next sequence of code works in conjunction with the + * rewind_if_safe_syscall_function(). If a signal is taken + * and the interrupted PC is anywhere between 'safe_syscall_start' + * and 'safe_syscall_end' then we rewind it to 'safe_syscall_start'. + * The code sequence must therefore be able to cope with this, and + * the syscall instruction must be the final one in the sequence. + */ +safe_syscall_start: + /* If signal_pending is non-zero, don't do the call */ + ld.w $t1, $t0, 0 + bnez $t1, 0f + syscall 0 +safe_syscall_end: + /* code path for having successfully executed the syscall */ + jr $ra + +0: + /* code path when we didn't execute the syscall */ + li.w $a0, -TARGET_ERESTARTSYS + jr $ra + .cfi_endproc + + .size safe_syscall_base, .-safe_syscall_base