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[2001:4830:134:3::11]) by mx.google.com with ESMTPS id 62si201801uay.237.2017.03.07.08.11.54 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 07 Mar 2017 08:11:55 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) client-ip=2001:4830:134:3::11; Authentication-Results: mx.google.com; dkim=fail header.i=@linaro.org; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 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]:51446 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1clHiK-0003ua-LT for patch@linaro.org; Tue, 07 Mar 2017 11:11:52 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48938) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1clHVQ-0000ul-7J for qemu-devel@nongnu.org; Tue, 07 Mar 2017 10:58:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1clHVO-0008C0-FI for qemu-devel@nongnu.org; Tue, 07 Mar 2017 10:58:32 -0500 Received: from mail-wm0-x231.google.com ([2a00:1450:400c:c09::231]:36669) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1clHVO-0008BW-97 for qemu-devel@nongnu.org; Tue, 07 Mar 2017 10:58:30 -0500 Received: by mail-wm0-x231.google.com with SMTP id n11so93408762wma.1 for ; Tue, 07 Mar 2017 07:58:30 -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=W/wNiN9WSZB11jGiT6wPwXMv1eWyZX+lqA1Jrn60mUY=; b=NYERDa+3S3/HUJEsamXKPSP6YjlgRQcwAJ2Ea+qqHYQbx5knZllBfFyHkA3GPdp6gR tR6aBX1DxvGbmbIJR9ofTxljCL4UAmFo5655Tp1h9lhygzWDnvwfoK9Z/SHvNXTSRfX5 ghYHfmkJVlaEPAGmNxiCcLmoGVBdpBgulmeEc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=W/wNiN9WSZB11jGiT6wPwXMv1eWyZX+lqA1Jrn60mUY=; b=NmGlfdyyuR1dbfMjyc4lSr2Lj0MOGMrKCicQg0X0r/K9qnCZr9zQiu0mI43WcTOzgl kMJeSAmiHgBmAuh0CMt3Yowmd1pMzm/qEboE1ia/hHwchOSsgEs4HFuDOpm6FrqwQ6oP T1fDQI830/7nIBTakmhkvvmGhVI7v/9vXH5QIQk7iYCAqyBaRPf3T2YejUpL0wJ7Moqd ewl3DqqhEQHAyTcxg7pvPCSD0DPXNRmjKOd9L5wDbNhhrscPlmHzAwwvVVFpLMdb9qFk FrFOtWyQp/NgEy2oLk89a883DbZTGz/RHOLampiOQqVPKPWPZ76XlwrxKERVwPaoA+0D 5hfA== X-Gm-Message-State: AMke39nNP3ZFX3o+SmN2I8kDgFClTHo1+dK/5qkcQUOLvImvtEX0Pp4u+R2pAiBKePPKDxw0 X-Received: by 10.28.62.144 with SMTP id l138mr1495440wma.50.1488902308993; Tue, 07 Mar 2017 07:58:28 -0800 (PST) Received: from zen.linaro.local ([81.128.185.34]) by smtp.gmail.com with ESMTPSA id b17sm1039351wma.33.2017.03.07.07.58.26 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 07 Mar 2017 07:58:26 -0800 (PST) Received: from zen.linaroharston (localhost [127.0.0.1]) by zen.linaro.local (Postfix) with ESMTP id EEEA63E302A; Tue, 7 Mar 2017 15:50:54 +0000 (GMT) From: =?utf-8?q?Alex_Benn=C3=A9e?= To: peter.maydell@linaro.org, rth@twiddle.net, pbonzini@redhat.com Date: Tue, 7 Mar 2017 15:50:50 +0000 Message-Id: <20170307155054.5833-8-alex.bennee@linaro.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170307155054.5833-1-alex.bennee@linaro.org> References: <20170307155054.5833-1-alex.bennee@linaro.org> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a00:1450:400c:c09::231 Subject: [Qemu-devel] [PATCH v3 07/11] translate-all: exit cpu_restore_state early if translating X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mttcg@listserver.greensocs.com, nikunj@linux.vnet.ibm.com, Peter Crosthwaite , a.rigo@virtualopensystems.com, qemu-devel@nongnu.org, cota@braap.org, bobby.prani@gmail.com, =?utf-8?q?Alex_Benn=C3=A9e?= , fred.konrad@greensocs.com Errors-To: qemu-devel-bounces+patch=linaro.org@nongnu.org Sender: "Qemu-devel" The translation code uses cpu_ld*_code which can trigger a tlb_fill which if it fails will erroneously attempts a fault resolution. This never works during translation as the TB being generated hasn't been added yet. The target should have checked retaddr before calling cpu_restore_state but for those that have yet to be fixed we do it here to avoid a recursive tb_lock() under MTTCG's new locking regime. Signed-off-by: Alex Bennée --- v3 - check retaddr instead - reword commit/comments to be clearer --- translate-all.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) -- 2.11.0 Reviewed-by: Richard Henderson diff --git a/translate-all.c b/translate-all.c index d42d003e67..34480aebba 100644 --- a/translate-all.c +++ b/translate-all.c @@ -333,6 +333,19 @@ bool cpu_restore_state(CPUState *cpu, uintptr_t retaddr) TranslationBlock *tb; bool r = false; + /* A retaddr of zero is invalid so we really shouldn't have ended + * up here. The target code has likely forgotten to check retaddr + * != 0 before attempting to restore state. We return early to + * avoid blowing up on a recursive tb_lock(). The target must have + * previously survived a failed cpu_restore_state because + * tb_find_pc(0) would have failed anyway. It still should be + * fixed though. + */ + + if (!retaddr) { + return r; + } + tb_lock(); tb = tb_find_pc(retaddr); if (tb) {