From mboxrd@z Thu Jan 1 00:00:00 1970 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 59D4AC433F5 for ; Wed, 17 Nov 2021 16:06:20 +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 F366861B49 for ; Wed, 17 Nov 2021 16:06:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org F366861B49 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:39346 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mnNRz-0003Ae-5d for qemu-devel@archiver.kernel.org; Wed, 17 Nov 2021 11:06:19 -0500 Received: from eggs.gnu.org ([209.51.188.92]:50408) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mnNQD-000098-7V for qemu-devel@nongnu.org; Wed, 17 Nov 2021 11:04:29 -0500 Received: from [2a00:1450:4864:20::42d] (port=41875 helo=mail-wr1-x42d.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mnNQB-00032b-72 for qemu-devel@nongnu.org; Wed, 17 Nov 2021 11:04:28 -0500 Received: by mail-wr1-x42d.google.com with SMTP id a9so5652879wrr.8 for ; Wed, 17 Nov 2021 08:04:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=2fImwBgyiUxW2cyko0HSyaGAM3opUFv591S/8+t1daM=; b=wu+5e7ofA/OOBEA95ehmKjeTVCVHPJzJhXMi5p9R+MD5kZ6NbsXRL0n7vLDTfMVxD5 rxHpdrVk8RUqf/IWVeSgLivxoKSKOZ/mb7C5V2A48MQl3Ldyju8LZ/6yJ3XOnFEJlQe4 kYFcx1IENd6tzZpXIHx7Of+IYPwqUtHUhnV6RZfySSwExdUfGS9I/CDrvnxJPxRSBVfl A6oLiWcynqL0sh5xx+y8ABOPGPp1sOFxiJS4a2koSIesTYEyc1CvIkzk9OIWHXcy5mdD E5gRUH2tRKdmCtyrq5sEkBuH3TmuixKoXZdqCraE9FXa9XteB17Fobc5onAvsSEY4WGd 66AA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=2fImwBgyiUxW2cyko0HSyaGAM3opUFv591S/8+t1daM=; b=OQPuw4hYCDpYAhMQkO/t3UZyU8ruWHNnpx8Os1vEe4CisKUKN/p2bYlktVsvb5R7fa lTn2b/PBMwJal1vu2nKZ/nyf/Ou8QCeDiH3MDbjl5GHMsTSBamWMn9CfdBWrQz/7FDBv vzl1WKL4bubHCZvMPTNeT2iGqczsnIgGAF63C4I5ZEglQCt2ZJxvWL50MKekZD9jQDgZ ss0YhmB2nMj602j0/58FSuMckbhENKvaAeis7YkVpI8VcckYERpRo4iRov3ZrBYWZTm2 rtC9DiI4HuISLop+q2l5HCpe/yPIoYhWpqDPMoxEAWL6qFTrfntY1xTCPELfOhtuOuYg W5PQ== X-Gm-Message-State: AOAM533Zll5vQTjJpbiCpYyEpLYt2FEPX50v4GzNeEMazW2rXhqqcK4x t7R03hXFgpvoCR3j+BjuOIdNj7uvzHatzb5KrdE= X-Google-Smtp-Source: ABdhPJwyE1t3fNSXbOqI4ooQK5iw+2R9lC5z3ZeKl+qTi8PyR7W8fFCpPyauRf2Z0MaVla++tyve7w== X-Received: by 2002:a5d:64cc:: with SMTP id f12mr21231356wri.322.1637165065751; Wed, 17 Nov 2021 08:04:25 -0800 (PST) Received: from localhost.localdomain (101.red-176-80-44.dynamicip.rima-tde.net. [176.80.44.101]) by smtp.gmail.com with ESMTPSA id m2sm5826742wml.15.2021.11.17.08.04.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Nov 2021 08:04:25 -0800 (PST) From: Richard Henderson To: qemu-devel@nongnu.org Subject: [PATCH v5 05/17] common-user/host/mips: Add safe-syscall.inc.S Date: Wed, 17 Nov 2021 17:04:00 +0100 Message-Id: <20211117160412.71563-6-richard.henderson@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211117160412.71563-1-richard.henderson@linaro.org> References: <20211117160412.71563-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Host-Lookup-Failed: Reverse DNS lookup failed for 2a00:1450:4864:20::42d (failed) Received-SPF: pass client-ip=2a00:1450:4864:20::42d; envelope-from=richard.henderson@linaro.org; helo=mail-wr1-x42d.google.com X-Spam_score_int: -12 X-Spam_score: -1.3 X-Spam_bar: - X-Spam_report: (-1.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, PDS_HP_HELO_NORDNS=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no 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: laurent@vivier.eu, imp@bsdimp.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Signed-off-by: Richard Henderson --- common-user/host/mips/hostdep.h | 2 + common-user/host/mips/safe-syscall.inc.S | 135 +++++++++++++++++++++++ 2 files changed, 137 insertions(+) create mode 100644 common-user/host/mips/hostdep.h create mode 100644 common-user/host/mips/safe-syscall.inc.S diff --git a/common-user/host/mips/hostdep.h b/common-user/host/mips/hostdep.h new file mode 100644 index 0000000000..b18aca1deb --- /dev/null +++ b/common-user/host/mips/hostdep.h @@ -0,0 +1,2 @@ +/* We have a safe-syscall.inc.S */ +#define HAVE_SAFE_SYSCALL diff --git a/common-user/host/mips/safe-syscall.inc.S b/common-user/host/mips/safe-syscall.inc.S new file mode 100644 index 0000000000..1e2f5a079c --- /dev/null +++ b/common-user/host/mips/safe-syscall.inc.S @@ -0,0 +1,135 @@ +/* + * 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 + * + * Written by Richard Henderson + * Copyright (C) 2021 Linaro, Inc. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "sys/regdef.h" +#include "sys/asm.h" + + .text + .set nomips16 + .set noreorder + + .global safe_syscall_start + .global safe_syscall_end + .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'). + */ + +#if _MIPS_SIM == _ABIO32 +/* Do not allocate a stack frame and store into the parameter space. */ +#define FRAME 0 +#define ERRNOP 4 +#else +/* Allocate a stack frame and store into the first allocated slot. */ +#define FRAME 16 +#define ERRNOP 0 +#endif + +NESTED(safe_syscall_base, FRAME, ra) + .cfi_startproc +#if _MIPS_SIM == _ABIO32 + /* + * The syscall calling convention is nearly the same as C: + * we enter with a0 == &signal_pending + * a1 == &errno + * a2 == syscall number + * a3, stack == syscall arguments + * and return the result in a0 + * and the syscall instruction needs + * v0 == syscall number + * a0 ... a3, stack == syscall arguments + * and returns the result in v0 + * Shuffle everything around appropriately. + */ + move t0, a0 /* signal_pending pointer */ + sw a1, ERRNOP(sp) /* errno pointer */ + move v0, a2 /* syscall number */ + move a0, a3 /* syscall arguments */ + lw a1, 16(sp) + lw a2, 20(sp) + lw a3, 24(sp) + lw t4, 28(sp) + lw t5, 32(sp) + lw t6, 40(sp) + lw t7, 44(sp) + sw t4, 16(sp) + sw t5, 20(sp) + sw t6, 24(sp) + sw t7, 28(sp) +#else + PTR_ADDIU sp, sp, -FRAME + .cfi_adjust_cfa_offset FRAME + + /* + * The syscall calling convention is nearly the same as C: + * we enter with a0 == &signal_pending + * a1 == &errno + * a2 == syscall number + * a3 ... a7, stack == syscall arguments + * and return the result in a0 + * and the syscall instruction needs + * v0 == syscall number + * a0 ... a5 == syscall arguments + * and returns the result in v0 + * Shuffle everything around appropriately. + */ + move t0, a0 /* signal_pending pointer */ + PTR_S a1, ERRNOP(sp) /* save errno pointer */ + move v0, a2 /* syscall number */ + move a0, a3 /* syscall arguments */ + move a1, a4 + move a2, a5 + move a3, a6 + move a4, a7 + ld a5, 16(sp) +#endif + + /* + * 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 */ + lw t1, 0(t0) + bnez t1, 0f + nop + syscall +safe_syscall_end: + + /* code path for having successfully executed the syscall */ + bnez a3, 1f + nop + jr ra + PTR_ADDIU sp, sp, FRAME + + /* code path when we didn't execute the syscall */ +0: li v0, TARGET_ERESTARTSYS + + /* code path setting errno */ +1: PTR_L t0, ERRNOP(sp) + sw v0, 0(t0) /* store errno */ + li v0, -1 + jr ra + PTR_ADDIU sp, sp, FRAME + + .cfi_endproc +END(safe_syscall_base) -- 2.25.1