From nobody Wed Nov 27 07:44:53 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=linaro.org ARC-Seal: i=1; a=rsa-sha256; t=1700493191; cv=none; d=zohomail.com; s=zohoarc; b=LS/h+nURqww/3MOErkch61fjkr1qWqRM43IE7CtlhahL3yF45H86grB1UcFKhA5xVcKZjmLbhfo46YURY+j4Sm7f8AqSCagvt8wqfR2m8ybvA8dko0LY/6JiLHzWSP/xPTY1DYzWvgbL0jC4IB8r8d7ruFrKeWOqfYSlCssdXKM= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1700493191; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=/Am29rNstmoBjPWHdKzUHbk8KZyMNjdmqHD061pd8s4=; b=XwR6my6AXZYo59vApfo++CQoUA2pOa+87Y5HNOfh9hfFiuSZfjnw2bc1Pm+mdLrmzB+oHfWn48uUArhhvi5JqPn1NQhDjyVSlDSebo4O6iY/vVq0YLOhUTjyJVgssyKlHdrbKyzY2pGeu8Vit3CQUcAGOm7hd4+/oKBzrkoZ690= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 170049319158995.82993544299268; Mon, 20 Nov 2023 07:13:11 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r55tl-0006T4-E4; Mon, 20 Nov 2023 10:09:17 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r55tQ-0005sf-W3 for qemu-devel@nongnu.org; Mon, 20 Nov 2023 10:08:59 -0500 Received: from mail-wm1-x32a.google.com ([2a00:1450:4864:20::32a]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1r55tC-0001EZ-RB for qemu-devel@nongnu.org; Mon, 20 Nov 2023 10:08:52 -0500 Received: by mail-wm1-x32a.google.com with SMTP id 5b1f17b1804b1-4083ac51d8aso16963245e9.2 for ; Mon, 20 Nov 2023 07:08:41 -0800 (PST) Received: from draig.lan ([85.9.250.243]) by smtp.gmail.com with ESMTPSA id y4-20020a5d4ac4000000b003316c8ad545sm10450206wrs.76.2023.11.20.07.08.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Nov 2023 07:08:38 -0800 (PST) Received: from draig.lan (localhost [IPv6:::1]) by draig.lan (Postfix) with ESMTP id A0DC365775; Mon, 20 Nov 2023 15:08:34 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1700492921; x=1701097721; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=/Am29rNstmoBjPWHdKzUHbk8KZyMNjdmqHD061pd8s4=; b=xvpDD/VqOy5u8dMnxMvewAW6XKwA+xGG16bTSKvRO/u9Inu1Wy1HZphlrm/XPAhHRO IXwtUQclud/8Uas5SIx084VffpX8bCiFlGdLnWsJEFtbgQeGhxAhtPjiQAVSDiAejTEf 6gnhgjXOwDsiOYB0oKlltEurluvovnv0DnGb3yTaLpjJM0CPv+9HIwavoXuN3Ab63t/4 BVT1yqcglWEI9mlxo6yqnrq66hNnsO3t1ITvxI/3uJ7I9KWy63oLy1YYHAwnfiN13wHz LChe92hArzydqrA1w2YYe2aieOI74/Rih9jNPOAUmONZVOhcLrPK0ohUfYv+E5wjPg7e VwFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700492921; x=1701097721; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/Am29rNstmoBjPWHdKzUHbk8KZyMNjdmqHD061pd8s4=; b=sJnz7m5yM9hah0qmm5uif5O8DGEEQBJXXJJGgQSwmVfn35VcNVlVRBPXJKoVEKx/JG UsYxq4GYmMONnByE6aa4UoL7K+4md9Osp8W7J3V6GQsm1w5MRCoDmmUFvaf0BB0hm4kN QoQfakd0NZU965PLCwL0HrsxgSe6pWxQ9/mpxOtSdJsOecGMVGqo9UnjhBnV4UFiz1Ru keGMgtriRmlTxka/xqGxsWhwGi+vT2TQ+vBqBkuqrsJyNBQMu9Q3ldFqyp74aU/7zo+2 ym+aIBgwkApGJFMu1eIPkJGpmsRtSxYoMdnyoqEbmzw0xLppxrZ+fPIo1xn+y0eICY6m PcKQ== X-Gm-Message-State: AOJu0YwEz0ADR8azdqaaSbCuDy5IMjTie9YJ8qcdEi4tAHDsH3G6fyKD HFxXcnhwC7XECH/TBzwdo1R9Kw== X-Google-Smtp-Source: AGHT+IGXKd2U+WEIncOd5SP1kVcLtYZr5FJl/EL76EFXdswtHcZ2pP6rvl7lvX1ZkKAGW+XfP2QXqA== X-Received: by 2002:a7b:c342:0:b0:40a:4a7d:606b with SMTP id l2-20020a7bc342000000b0040a4a7d606bmr6547024wmj.40.1700492920613; Mon, 20 Nov 2023 07:08:40 -0800 (PST) From: =?UTF-8?q?Alex=20Benn=C3=A9e?= To: qemu-devel@nongnu.org Cc: Wainer dos Santos Moschetta , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= , Mahmoud Mandour , Peter Maydell , David Hildenbrand , =?UTF-8?q?Alex=20Benn=C3=A9e?= , qemu-s390x@nongnu.org, Beraldo Leal , qemu-arm@nongnu.org, devel@lists.libvirt.org, qemu-ppc@nongnu.org, Daniel Henrique Barboza , Paolo Bonzini , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Alexandre Iooss , Marek Vasut , Thomas Huth , Chris Wulff , Ilya Leoshkevich , Richard Henderson , Nicholas Piggin Subject: [PATCH v2 07/14] docs/emulation: expand warning about semihosting Date: Mon, 20 Nov 2023 15:08:26 +0000 Message-Id: <20231120150833.2552739-8-alex.bennee@linaro.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231120150833.2552739-1-alex.bennee@linaro.org> References: <20231120150833.2552739-1-alex.bennee@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2a00:1450:4864:20::32a; envelope-from=alex.bennee@linaro.org; helo=mail-wm1-x32a.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @linaro.org) X-ZM-MESSAGEID: 1700493192284100001 A surprising feature of calls like SYS_READC is this can cause QEMU to indefinitely block as there is no handling for EOF. Clarifies: https://gitlab.com/qemu-project/qemu/-/issues/1963 Signed-off-by: Alex Benn=C3=A9e Reviewed-by: Richard Henderson --- docs/about/emulation.rst | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/docs/about/emulation.rst b/docs/about/emulation.rst index 0ad0b86f0d..a2eefe3f3f 100644 --- a/docs/about/emulation.rst +++ b/docs/about/emulation.rst @@ -129,8 +129,9 @@ causing most hypervisors to trap and fault on them. .. warning:: Semihosting inherently bypasses any isolation there may be between the guest and the host. As a result a program using semihosting can - happily trash your host system. You should only ever run trusted - code with semihosting enabled. + happily trash your host system. Some semihosting calls (e.g. + ``SYS_READC``) can block execution indefinitely. You should only + ever run trusted code with semihosting enabled. =20 Redirection ~~~~~~~~~~~ --=20 2.39.2