From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id ULP6OFWf7F8ACwAAWB0awg (envelope-from ) for ; Wed, 30 Dec 2020 10:40:05 -0500 Received: by simark.ca (Postfix, from userid 112) id D6EAD1F0B7; Wed, 30 Dec 2020 10:40:05 -0500 (EST) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-1.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id ADC611E965 for ; Wed, 30 Dec 2020 10:40:00 -0500 (EST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 627C238618C9; Wed, 30 Dec 2020 15:40:00 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 627C238618C9 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1609342800; bh=lLEHJzAnurWWo3YSStBQRrJdceSIC6s2zt2N5CAEW6c=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=nKFfgSTm43PsAzUibq9CzIjh56LR39ATPcNQa029qoRnHMm1z9OfJXGWsyfpmx3zI IStM4H4TjM9wPVt/IoFDeVHvms9Ai7AeBiURNh5R2pqbwwysquv5v6bwhtszJyM+ih L0Ckc39H05WCSIR8rwWZJZPmj5BwL6T8xKuHR+Fc= Received: from mail-qk1-x72c.google.com (mail-qk1-x72c.google.com [IPv6:2607:f8b0:4864:20::72c]) by sourceware.org (Postfix) with ESMTPS id 1F78C388E812 for ; Wed, 30 Dec 2020 15:39:58 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 1F78C388E812 Received: by mail-qk1-x72c.google.com with SMTP id z11so14176434qkj.7 for ; Wed, 30 Dec 2020 07:39:58 -0800 (PST) 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=lLEHJzAnurWWo3YSStBQRrJdceSIC6s2zt2N5CAEW6c=; b=tbRADefi49mRvcFUFV7XMiPV7IQbnkU8c30QuKb2P8xJ0fbvhgRceRWJ1A8J5b8jWh 5wA7V/2iG7Dr5gzfJFh387+t+69bo/G8y3AoNDNDMAkD48JVi/o5VdnQaHjjJffrAODE jKJY8r7i2IbKQIPJCi2vDq1auhTVVvZ87/+7CZeGnpIrCSJWK3bokJQVeYmZgX/8gKDf C9r+cqetJ7NcBU8YzJ0UMmjrjAFU4+Sk+7istlBupI3C4x/EwmEKMTFllHzR5mwU+RIe Rxu6BurUXzO2zQNVdi3viTs1EmJD99ggEypZYEHLAYmhrGxOVOcaLUaTES0xZCs/UfS5 Is0w== X-Gm-Message-State: AOAM531tUUGXDICCbJreo60kARKv3FB7DsU01G4WyTdaPcrl/2O5g+wo RAmQqscgp4Sot5z9jHAG0cEqCVOqdVo72g== X-Google-Smtp-Source: ABdhPJztAHG1Uy3+g0XMaoWEbRqUdzPc9GJJwJBrJc9BeLIUntZLw27zJ0yhJmDPezPbRm6oZlwFgA== X-Received: by 2002:a37:9c16:: with SMTP id f22mr53400799qke.67.1609342797519; Wed, 30 Dec 2020 07:39:57 -0800 (PST) Received: from localhost.localdomain ([2804:7f0:8284:370e:c9ba:c4ec:737b:57da]) by smtp.gmail.com with ESMTPSA id f6sm28589336qkh.2.2020.12.30.07.39.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Dec 2020 07:39:57 -0800 (PST) To: gdb-patches@sourceware.org Subject: [PATCH v4 17/25] AArch64: Report tag violation error information Date: Wed, 30 Dec 2020 12:39:08 -0300 Message-Id: <20201230153916.1586725-18-luis.machado@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201230153916.1586725-1-luis.machado@linaro.org> References: <20201230153916.1586725-1-luis.machado@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Luis Machado via Gdb-patches Reply-To: Luis Machado Cc: david.spickett@linaro.org Errors-To: gdb-patches-bounces@sourceware.org Sender: "Gdb-patches" Updates on v4: - Print exception error. - Update function names. -- Whenever a memory tag violation occurs, we get a SIGSEGV. Additional information can be obtained through the siginfo data structure. For AArch64 the Linux kernel may expose the fault address and tag information, if we have a synchronous event. Otherwise there is no fault address available. The synchronous event looks like this: -- (gdb) continue Continuing. Program received signal SIGSEGV, Segmentation fault Memory tag violation while accessing address 0x0000fffff7ff8000 Allocation tag 0x1. -- The asynchronous event looks like this: -- (gdb) continue Continuing. Program received signal SIGSEGV, Segmentation fault Memory tag violation Fault address unavailable. -- gdb/ChangeLog: YYYY-MM-DD Luis Machado * aarch64-linux-tdep.c (aarch64_linux_report_signal_info): New function. (aarch64_linux_init_abi): Register aarch64_linux_report_signal_info as the report_signal_info hook. * arch/aarch64-linux.h (SEGV_MTEAERR): Define. (SEGV_MTESERR): Define. --- gdb/aarch64-linux-tdep.c | 66 ++++++++++++++++++++++++++++++++++++ gdb/arch/aarch64-mte-linux.h | 6 ++++ 2 files changed, 72 insertions(+) diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c index af43cf666a..1bdd127e0d 100644 --- a/gdb/aarch64-linux-tdep.c +++ b/gdb/aarch64-linux-tdep.c @@ -1702,6 +1702,69 @@ aarch64_linux_memtag_to_string (struct gdbarch *gdbarch, return string_printf ("0x%s", phex_nz (tag, sizeof (tag))); } +/* AArch64 Linux implementation of the report_signal_info gdbarch + hook. Displays information about possible memory tag violations. */ + +static void +aarch64_linux_report_signal_info (struct gdbarch *gdbarch, + struct ui_out *uiout, + enum gdb_signal siggnal) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + if (!tdep->has_mte () || siggnal != GDB_SIGNAL_SEGV) + return; + + CORE_ADDR fault_addr = 0; + long si_code = 0; + + try + { + /* Sigcode tells us if the segfault is actually a memory tag + violation. */ + si_code = parse_and_eval_long ("$_siginfo.si_code"); + + fault_addr + = parse_and_eval_long ("$_siginfo._sifields._sigfault.si_addr"); + } + catch (const gdb_exception_error &exception) + { + exception_print (gdb_stderr, exception); + return; + } + + /* If this is not a memory tag violation, just return. */ + if (si_code != SEGV_MTEAERR && si_code != SEGV_MTESERR) + return; + + uiout->text ("\n"); + + uiout->field_string ("sigcode-meaning", _("Memory tag violation")); + + /* For synchronous faults, show additional information. */ + if (si_code == SEGV_MTESERR) + { + uiout->text (_(" while accessing address ")); + uiout->field_core_addr ("fault-addr", gdbarch, fault_addr); + uiout->text ("\n"); + + gdb::optional atag = aarch64_mte_get_atag (fault_addr); + + if (!atag.has_value ()) + uiout->text (_("Allocation tag unavailable")); + else + { + uiout->text (_("Allocation tag ")); + uiout->field_string ("allocation-tag", hex_string (*atag)); + } + } + else + { + uiout->text ("\n"); + uiout->text (_("Fault address unavailable")); + } +} + static void aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { @@ -1782,6 +1845,9 @@ aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) /* Register a hook for converting a memory tag to a string. */ set_gdbarch_memtag_to_string (gdbarch, aarch64_linux_memtag_to_string); + + set_gdbarch_report_signal_info (gdbarch, + aarch64_linux_report_signal_info); } /* Initialize the aarch64_linux_record_tdep. */ diff --git a/gdb/arch/aarch64-mte-linux.h b/gdb/arch/aarch64-mte-linux.h index d44cae92a6..0f181a8595 100644 --- a/gdb/arch/aarch64-mte-linux.h +++ b/gdb/arch/aarch64-mte-linux.h @@ -35,6 +35,12 @@ #define AARCH64_MTE_LOGICAL_TAG_START_BIT 56 #define AARCH64_MTE_LOGICAL_MAX_VALUE 0xf +/* Memory tagging definitions. */ +#ifndef SEGV_MTEAERR +# define SEGV_MTEAERR 8 +# define SEGV_MTESERR 9 +#endif + /* Memory tag types for AArch64. */ enum class aarch64_memtag_type { -- 2.25.1