From patchwork Tue Nov 23 17:37:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Henderson X-Patchwork-Id: 519328 Delivered-To: patch@linaro.org Received: by 2002:ac0:c605:0:0:0:0:0 with SMTP id p5csp8980126imj; Tue, 23 Nov 2021 09:43:37 -0800 (PST) X-Google-Smtp-Source: ABdhPJwjXdRX66DC4uUcpn9y+WGdFdYoF0pfID/uQVQin1Fvmwg6EN6ioBWmEQKg/umiX3G62bo5 X-Received: by 2002:a1f:9158:: with SMTP id t85mr13558385vkd.8.1637689417134; Tue, 23 Nov 2021 09:43:37 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1637689417; cv=none; d=google.com; s=arc-20160816; b=TlnlIvT6T7Xmibi0/lcBmYBM5mKe84pMRNk8K5HmHZ3MypbNYwelK3l3a+OhmtZSE7 TgLjuMkjH7RYkbUVSOq3arFCrjhxbGSwiA5PsbfSqs61u2dmDgxgKEZAoSCbsMMjrYi9 eIx+gJc+umbn0Nc3pTv0MmpNpanamt7WQOSQZa/UHjgAuCzgSM0kn/e4/Q4/kX9j0Op5 l2jxEbgDHFIx9XZJRtgDEriPzGO0yQ3lcy4XWpRAaYUJ+yGCDqQyz/GA1DVzqPaQGuJi GsTTicZs0XJmB8Tczb/5bDePAf2NZznmbCWWK5L2rUMDHEPKCOf4I9kFpcMaeLpJgM1y 8bVQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:cc:list-subscribe:list-help:list-post:list-archive :list-unsubscribe:list-id:precedence:content-transfer-encoding :mime-version:references:in-reply-to:message-id:date:subject:to:from :dkim-signature; bh=N7ifV7lHO8lRE2Wpho0vLQOIlb6dvWhebWkO0CZFmhw=; b=oBl7QB4d8tTlz5xO6/SZC2qZCE78Y6SvHoF1XdMsVv1P+3foJxAwqmLvpnYGLcxtHL GoZ0voroeNS+FcwS3cqcWbWWVZqSzP3Hnh0KMtLVU6A7kXF2BbW4ioRlREsOyETrFgVf gi5xEEyd/mCnwRT8Ku3iLG4drNesMM46LRsslgWaaJeCJFaYi1Wq7vPxzEA5wm8XopxG l2wpD3ix997FEvE8nsMvEYne5IILkpnjbEcEIYTlgfkw0rGQJbB8nxX4Ohr8QvDCVQl8 RDb33AU+xPocmIcjsH4yzHz+T6TbKCxFeHNnXHHoSJ7/HJitVxTMPtovsPkMt8T09tjk aO9Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@linaro.org header.s=google header.b=OlXCwYDh; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org"; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from lists.gnu.org (lists.gnu.org. [209.51.188.17]) by mx.google.com with ESMTPS id y10si38240482vko.92.2021.11.23.09.43.37 for (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 23 Nov 2021 09:43:37 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; Authentication-Results: mx.google.com; dkim=fail header.i=@linaro.org header.s=google header.b=OlXCwYDh; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org"; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from localhost ([::1]:45554 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mpZpQ-0006mo-H4 for patch@linaro.org; Tue, 23 Nov 2021 12:43:36 -0500 Received: from eggs.gnu.org ([209.51.188.92]:52234) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mpZkC-00042W-FN for qemu-devel@nongnu.org; Tue, 23 Nov 2021 12:38:12 -0500 Received: from [2a00:1450:4864:20::331] (port=33729 helo=mail-wm1-x331.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1mpZkA-0004zp-RM for qemu-devel@nongnu.org; Tue, 23 Nov 2021 12:38:12 -0500 Received: by mail-wm1-x331.google.com with SMTP id r9-20020a7bc089000000b00332f4abf43fso2439600wmh.0 for ; Tue, 23 Nov 2021 09:38:10 -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=N7ifV7lHO8lRE2Wpho0vLQOIlb6dvWhebWkO0CZFmhw=; b=OlXCwYDhzfokR1zsTCPF+AICPDesNr1MJNBDIYnUqFS7iiwhrfMgDXiyQbk7bYrpE0 Qi4HxbciewP96tgbAPM6PE17226wPbfZML8tR09TBeI6hC7JuB6tnSNz3S/MQlbqRNnw 31bApKF7fRLy1T1UNfS+EsOrwft88NisEXU0lKKyakU2xKUaDr3RWdm5+QEKhNN1Wka/ 8hr30bDDANekcM4F3WJYvPiNgvDUgZvWX7sj5ntUmjFcu3VRnOHjXt0LAb1sjatJnA8a Iiii5VvfdPCvsDJaJ5l6wcOdmlW+2neyRsGtOkxl8/txxv/+SqSapxymwbsHAsKkIfcu FHog== 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=N7ifV7lHO8lRE2Wpho0vLQOIlb6dvWhebWkO0CZFmhw=; b=sGl7cbfRe5pYcNIcuXAb8+c8IHmYkEbA8rx8H6pIqdWRcZtKJJc5nzhHMDhR2pEgvC BQq4AxPydVn7nQikkOgyEv5CeKt3b5wFX5ewsl+uONYsxCp/hC5HDprjpvKHIf3Mo53D ce5Cg31VNj4NLbR41GtTsKHKNpfV98dICWSfQBNoSFS1iMSW2Zy2tQhrJl6emjQWJhXQ whSIYr/FPxwGEyWsdrVJb7GCJ6fDSuqbUYMu4ioA10UwwJHSC7bhBOzVQhdmry9aLb3D 9QQQlww9R3876XSBD+C2BXl6rso9uD7GQzWL6YgPw9mv2xgwqMR2xYPr3tCqIJNZocOZ nqAQ== X-Gm-Message-State: AOAM532gBLyqTK63ogTVOPBZTOgK1hI6daiLhFGzFDy6ay8fG7huv6R6 em5CkZtnDEFMEd5licbPk0SXDkyE+MlmZ7UDncw= X-Received: by 2002:a05:600c:6016:: with SMTP id az22mr5385546wmb.11.1637689089443; Tue, 23 Nov 2021 09:38:09 -0800 (PST) Received: from cloudburst.home (149.164.14.37.dynamic.jazztel.es. [37.14.164.149]) by smtp.gmail.com with ESMTPSA id n13sm13054883wrt.44.2021.11.23.09.38.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Nov 2021 09:38:08 -0800 (PST) From: Richard Henderson To: qemu-devel@nongnu.org Subject: [PATCH v6 04/16] linux-user/host/mips: Add safe-syscall.inc.S Date: Tue, 23 Nov 2021 18:37:47 +0100 Message-Id: <20211123173759.1383510-5-richard.henderson@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211123173759.1383510-1-richard.henderson@linaro.org> References: <20211123173759.1383510-1-richard.henderson@linaro.org> MIME-Version: 1.0 X-Host-Lookup-Failed: Reverse DNS lookup failed for 2a00:1450:4864:20::331 (failed) Received-SPF: pass client-ip=2a00:1450:4864:20::331; envelope-from=richard.henderson@linaro.org; helo=mail-wm1-x331.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+patch=linaro.org@nongnu.org Sender: "Qemu-devel" Signed-off-by: Richard Henderson Reviewed-by: Warner Losh --- linux-user/host/mips/hostdep.h | 3 + linux-user/host/mips/safe-syscall.inc.S | 123 ++++++++++++++++++++++++ 2 files changed, 126 insertions(+) create mode 100644 linux-user/host/mips/safe-syscall.inc.S diff --git a/linux-user/host/mips/hostdep.h b/linux-user/host/mips/hostdep.h index ba111d75c3..d9e90a096b 100644 --- a/linux-user/host/mips/hostdep.h +++ b/linux-user/host/mips/hostdep.h @@ -12,4 +12,7 @@ #ifndef MIPS_HOSTDEP_H #define MIPS_HOSTDEP_H +/* We have a safe-syscall.inc.S */ +#define HAVE_SAFE_SYSCALL + #endif diff --git a/linux-user/host/mips/safe-syscall.inc.S b/linux-user/host/mips/safe-syscall.inc.S new file mode 100644 index 0000000000..c6dd726001 --- /dev/null +++ b/linux-user/host/mips/safe-syscall.inc.S @@ -0,0 +1,123 @@ +/* + * 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 reorder + + .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'). + */ + +LEAF(safe_syscall_base) + .cfi_startproc +#if _MIPS_SIM == _ABIO32 + /* + * The syscall calling convention is nearly the same as C: + * we enter with a0 == &signal_pending + * a1 == syscall number + * a2, 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 */ + move v0, a1 /* syscall number */ + move a0, a2 /* syscall arguments */ + move a1, a3 + lw a2, 16(sp) + lw a3, 20(sp) + lw t4, 24(sp) + lw t5, 28(sp) + lw t6, 32(sp) + lw t7, 40(sp) + sw t4, 16(sp) + sw t5, 20(sp) + sw t6, 24(sp) + sw t7, 28(sp) +#else + /* + * 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 + * v0 == syscall number + * a0 ... a5 == syscall arguments + * and returns the result in v0 + * Shuffle everything around appropriately. + */ + move t0, a0 /* signal_pending pointer */ + move v0, a1 /* syscall number */ + move a0, a2 /* syscall arguments */ + move a1, a3 + move a2, a4 + move a3, a5 + move a4, a6 + move a5, a7 +#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, 2f + syscall +safe_syscall_end: + + /* code path for having successfully executed the syscall */ + bnez a3, 1f + jr ra + + /* code path when we didn't execute the syscall */ +2: li v0, TARGET_ERESTARTSYS + + /* code path setting errno */ + /* + * We didn't setup GP on entry, optimistic of the syscall success. + * We must do so now to load the address of the helper, as required + * by the ABI, into t9. + * + * Note that SETUP_GPX and SETUP_GPX64 are themselves conditional, + * so we can simply let the one that's not empty succeed. + */ +1: USE_ALT_CP(t0) + SETUP_GPX(t1) + SETUP_GPX64(t0, t1) + PTR_LA t9, safe_syscall_set_errno_tail + jr t9 + + .cfi_endproc +END(safe_syscall_base)