From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qv1-xf2d.google.com (mail-qv1-xf2d.google.com [IPv6:2607:f8b0:4864:20::f2d]) by sourceware.org (Postfix) with ESMTPS id CEA193987833 for ; Thu, 22 Oct 2020 20:01:59 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org CEA193987833 Received: by mail-qv1-xf2d.google.com with SMTP id t20so1632094qvv.8 for ; Thu, 22 Oct 2020 13:01:59 -0700 (PDT) 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; bh=2m/d33vccWLaT1NEjZGOjABFLlCWwFxqNDSyN+Fue/Q=; b=oHZWslE/aDRYKdk6yRNrjsksvgy1L4zdHmHnwBaGgRSE91dnCngbDVBMq419BS5trI gQSetmwPXTUwQGfrHg7cknW11a3MX6hcxnGh/6L4yh/yFk6fEeWtePf8u92Eyb6e/NT7 Ihm4VGgAqN3fcQTeons5xXG4M3FCDGO9nUrJq4LI7HIfOqVhuImxK68NV3IhxATJVkLF xvbSqz3QdGyHgDsICWu5C+cDjWGgINIzmUWcBXfkEtAAecf7rowFEVEqG/9OImNdXN7+ j+sCc3LLNeYQu/exA0NWylrv8pS/zazn4kQn6O3wGqmXLgvHBSKCKGs85ruv0po+N7+m AuVw== X-Gm-Message-State: AOAM530145lzqqyQcpCJaX7o8Xsyc1Cu2r0hFp0tvoVBfWlRFkbuQz3S kXx5tMdTtSxAzZb/aKO73623tE9hL1/Inw== X-Google-Smtp-Source: ABdhPJzB5eUjaVkWeZqzHIJKX8GuhgcyP2VGNdj6EYw5DRzg1t+NTDhVT9laLNq9fI7Gvoaw7DscZQ== X-Received: by 2002:a05:6214:104d:: with SMTP id l13mr4153021qvr.38.1603396919197; Thu, 22 Oct 2020 13:01:59 -0700 (PDT) Received: from localhost.localdomain ([2804:7f0:8284:1487:b9b1:f72a:8f1:600]) by smtp.gmail.com with ESMTPSA id a21sm1711208qkk.98.2020.10.22.13.01.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Oct 2020 13:01:58 -0700 (PDT) From: Luis Machado To: gdb-patches@sourceware.org Cc: alan.hayward@arm.com, jhb@FreeBSD.org, david.spickett@linaro.org Subject: [PATCH v2 22/24] Document new "x" and "print" memory tagging extensions Date: Thu, 22 Oct 2020 17:00:12 -0300 Message-Id: <20201022200014.5189-23-luis.machado@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201022200014.5189-1-luis.machado@linaro.org> References: <20201022200014.5189-1-luis.machado@linaro.org> X-Spam-Status: No, score=-12.0 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 autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org 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: , X-List-Received-Date: Thu, 22 Oct 2020 20:02:01 -0000 Document the changes to the "print" and "x" commands to support memory tagging. gdb/doc/ChangeLog: YYYY-MM-DD Luis Machado * gdb.texinfo (Data): Document memory tagging changes to the "print" command. (Examining Memory): Document memory tagging changes to the "x" command. (Memory Tagging): Update with more information on changes to the "x" and "print" commands. --- gdb/doc/gdb.texinfo | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 5056a021a5..5821210f55 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -9897,6 +9897,10 @@ If you omit @var{expr}, @value{GDBN} displays the last value again (from the conveniently inspect the same value in an alternative format. @end table +If the architecture supports memory tagging, the @code{print} command will +display pointer/memory tag mismatches if what is being printed is a pointer +or reference type. @xref{Memory Tagging}. + A more low-level way of examining data is with the @code{x} command. It examines data in memory at a specified address and prints it in a specified format. @xref{Memory, ,Examining Memory}. @@ -10664,7 +10668,8 @@ number is specified, memory is examined backward from @var{addr}. @item @var{f}, the display format The display format is one of the formats used by @code{print} (@samp{x}, @samp{d}, @samp{u}, @samp{o}, @samp{t}, @samp{a}, @samp{c}, -@samp{f}, @samp{s}), and in addition @samp{i} (for machine instructions). +@samp{f}, @samp{s}), @samp{i} (for machine instructions) and +@samp{m} (for displaying memory tags). The default is @samp{x} (hexadecimal) initially. The default changes each time you use either @code{x} or @code{print}. @@ -10759,6 +10764,22 @@ counter is shown with a @code{=>} marker. For example: 0x804838c : call 0x80482d4 @end smallexample +If the architecture supports memory tagging, the tags can be displayed by +using @samp{m}. @xref{Memory Tagging}. + +The information will be displayed once per granule size +(the amount of bytes a particular memory tag covers). For example, AArch64 +has a granule size of 16 bytes, so it will display a tag every 16 bytes. + +Due to the way @value{GDBN} prints information with the @code{x} command (not +aligned to a particular boundary), the tag information will refer to the +initial address displayed on a particular line. If a memory tag boundary +is crossed in the middle of a line displayed by the @code{x} command, it +will be displayed on the next line. + +The @samp{m} format doesn't affect any other specified formats that were +passed to the @code{x} command. + @cindex @code{$_}, @code{$__}, and value history The addresses and contents printed by the @code{x} command are not saved in the value history because there is often too much of them and they @@ -10826,8 +10847,9 @@ If the underlying architecture supports memory tagging, like AArch64 MTE or SPARC ADI do, @value{GDBN} can make use of it to validate addresses and pointers against memory allocation tags. -A command prefix of @code{mtag} gives access to the various memory tagging -commands. +The @code{print} (@pxref{Data}) and @code{x} (@pxref{Memory}) commands will +display tag information when appropriate, and a command prefix of @code{mtag} +gives access to the various memory tagging commands. The @code{mtag} commands are the following: -- 2.17.1