From patchwork Mon Mar 18 16:19:55 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?K=C3=A9vin_Le_Gouguec?= X-Patchwork-Id: 87322 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id B3C57385840C for ; Mon, 18 Mar 2024 16:21:06 +0000 (GMT) X-Original-To: gdb-patches@sourceware.org Delivered-To: gdb-patches@sourceware.org Received: from mail-lf1-x135.google.com (mail-lf1-x135.google.com [IPv6:2a00:1450:4864:20::135]) by sourceware.org (Postfix) with ESMTPS id 2ED573858CD1 for ; Mon, 18 Mar 2024 16:20:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 2ED573858CD1 Authentication-Results: sourceware.org; dmarc=pass (p=quarantine dis=none) header.from=adacore.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=adacore.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 2ED573858CD1 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2a00:1450:4864:20::135 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1710778842; cv=none; b=NnCMId14D3X3Ita7Y+jIUa7F+HY/t7CJBNfeeIs819aN2NhLcj39ITzrAI5/IyMoYWCn4UkaVOErCtyDdDAtuXBceJM8JlInSlOwpw+vgWLknwYSTNBqrkFLOVGMYmF9bA86qxNKHKQg6f8fC6YgDEqgEU6pMIFiwuDGRDCWnwY= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1710778842; c=relaxed/simple; bh=mYljHkQHETzRYfksCJ9Cg9ICqGsW0oEiSa5c08Tuh08=; h=DKIM-Signature:From:To:Subject:Date:Message-Id:MIME-Version; b=wHiB8XmNCa8wqPld6hih1f71CNaSdY/E/f4djT5ZwKq/gO51MjWgYt1+uCjLsdMPDaLqz5Ksf1Ylg+0/bbEVfn7LdeaQn8YvTgCHSTXJ/S67jciGHTaxHyb5uHNEB5aO4f545rCSaDlphoJ61Vg/xeh/yfAIJOLCznrd20MfTd4= ARC-Authentication-Results: i=1; server2.sourceware.org Received: by mail-lf1-x135.google.com with SMTP id 2adb3069b0e04-5131316693cso5585795e87.0 for ; Mon, 18 Mar 2024 09:20:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=adacore.com; s=google; t=1710778837; x=1711383637; darn=sourceware.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=JMdjPcsaII+rLKIeJN5L9HtHY/upyaUZ2l6iETS7hsQ=; b=NGSjL3GYFFk//YP6grCgCrR4PvOS2A4KtzEhBdyp5faGbdMV7LNhkxLkw5RrS6gknM vMLcEsYIQEJ3XS+NPvALGVFFOuAUqL5ZL795+k6qlydZILp3C5kRP8FQKtRI4x+1Ydyv 2j4eejI2G/Vh7eO6jHrg91XqIU7EUSkYu8pnlCNW1GpmAqt0+YKfnjn4AUztO3XRUl7z mSEgiSCRAt9exqHPeWimA9YXBSj4zYZyBRxsWPeDE4egnl2aGU98MX79HblmhYfHvsHw fqGL97DH82LjeHvRPqCLUeGpynSkjdI5eRR92XR1Wu+v+g9eulEpdUAxnbRr3oV/js4h Xl2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710778837; x=1711383637; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=JMdjPcsaII+rLKIeJN5L9HtHY/upyaUZ2l6iETS7hsQ=; b=igQLF2dWtR3pE/PdvEsUokA7CelC6cfFeDEf9CUEHR5IkRoj71At1t368HSfBTNXE1 Gy4Jo+sYAs6cR64m10VscQMz3j0pIKGVcybOKwJWwh+kvdFSssT+cnDpNKTxA5gdkpR2 11Q5F3Ep9eWAR1kr7TagBIQFpno+AavoxfVb3demyczrjeECihy41kWLi0OXlUcD5FKE Qz01aUN7nMnMJzzNr9RR3S+6FC/5/5SRKtowman/74dIphOkc0lJPlu6eAIfLuMteF5Y 4XFz5GTKUJmpqLLRnCgG7rxsNBKV7LCbhM4pPLMDqqTl4k3dyF6H0shiBPrVwJ9V8SQF 60UA== X-Gm-Message-State: AOJu0YwYXwUFv2Mispiy80bFxSEGn+pEdLexnKz91gb94tziBuAe9qDp V+x7LMviTAS2+2h/aBlGPxmEosOh04HoXUUGjupGsoIXOK2Qi5QVUfKIfTykIXdORfbNoPPem0d IRA== X-Google-Smtp-Source: AGHT+IHl76utlkbuJpu5D7csEgtZmg5f+fzCm22snGXrVwqg5bdIdxtENaId+a1pKEgqpZ06okqqQA== X-Received: by 2002:ac2:5b11:0:b0:513:d0d7:a298 with SMTP id v17-20020ac25b11000000b00513d0d7a298mr9069920lfn.55.1710778837081; Mon, 18 Mar 2024 09:20:37 -0700 (PDT) Received: from localhost.localdomain ([2.57.72.67]) by smtp.gmail.com with ESMTPSA id p10-20020a05600c1d8a00b004145cecb7bcsm1298214wms.45.2024.03.18.09.20.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Mar 2024 09:20:36 -0700 (PDT) From: =?utf-8?q?K=C3=A9vin_Le_Gouguec?= To: gdb-patches@sourceware.org Cc: =?utf-8?q?K=C3=A9vin_Le_Gouguec?= Subject: [PATCH] Refrain from asking debug stubs to read invalid memory Date: Mon, 18 Mar 2024 17:19:55 +0100 Message-Id: <20240318161955.668163-1-legouguec@adacore.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Spam-Status: No, score=-11.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gdb-patches-bounces+patchwork=sourceware.org@sourceware.org Some stubs take exception to this. For example we observe RTEMS's libdebugger freezing when asked to examine address zero on aarch64/xilinx_zynqmp_lp64_qemu. As of 2024-02-02 "gdb, types: Resolve pointer types dynamically" (f18fc7e56fb) this happens as early as 'target remote'. Ordinarily we would be greeted with… _User_extensions_Thread_switch (executing=0x0, heir=) at […]/cpukit/include/rtems/score/userextimpl.h:382 … but now, as language_defn::read_var_value calls resolve_dynamic_type with a "dummy" address and value, resolve_dynamic_type_internal receives a similarly "dummy" addr_stack, and attempts to read memory address zero: guard against that. --- gdb/gdbtypes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c index 599a696839e..917c997ad8c 100644 --- a/gdb/gdbtypes.c +++ b/gdb/gdbtypes.c @@ -2805,7 +2805,7 @@ resolve_dynamic_type_internal (struct type *type, if (addr_stack->valaddr.data () != NULL) pinfo.addr = extract_typed_address (addr_stack->valaddr.data (), type); - else + else if (addr_stack->addr != 0) pinfo.addr = read_memory_typed_address (addr_stack->addr, type); pinfo.next = addr_stack;