From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-x829.google.com (mail-qt1-x829.google.com [IPv6:2607:f8b0:4864:20::829]) by sourceware.org (Postfix) with ESMTPS id 511E83860C39 for ; Mon, 22 Mar 2021 13:22:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 511E83860C39 Received: by mail-qt1-x829.google.com with SMTP id a11so12251612qto.2 for ; Mon, 22 Mar 2021 06:22:09 -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:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=+EXAlxVqeud5n617FA3KuTJpPGVgiCS3v423H5eBiJg=; b=RkvoGWIYfOqwDxcdA2QIqh8IQ5MzRNggR9ZENCexn2245uwpfaTcij7w9KrK/rFclB NPziMaQv5YgVyZ9fgUB3lR0+XaogFG6mbx7Vxc2gsKGG8zLbkTQt3Ct6LnLMLvb8qp/x p3alrDlNaxLdbWzx2hABbQmdcQWOkpfXWwOJ/xm8m0NjRgFAodxDv7k9grZ3DebsGNsE pubvEANgLjeBsRJO3F6o3yo5QwKH2cM3OJWn/exmqopl6YDZepNGJvDqzzfjyqcRktDG GjC/39YgpHec3lojWOI9cVTOixEyPDLWMbVrjFbsvPAi2NJ1PvGk6C6LCMIUxcStHNz1 d/8A== X-Gm-Message-State: AOAM533Xtk1FySIfN5MP4ccZk7U2Tawi2s8I2FUs2gYdRdFjjTX0b9CP XFx6ZCaK+EkJEsF6oxNA+mazNSi/WZxThw== X-Google-Smtp-Source: ABdhPJzIcVbl2pdOWKjxltSrghx84l4ay5l1Okx6owgU0qpyEEiuEJpRmP39M8aTJEf+IRK3N9XosA== X-Received: by 2002:a05:622a:4d0:: with SMTP id q16mr9453126qtx.303.1616419328829; Mon, 22 Mar 2021 06:22:08 -0700 (PDT) Received: from localhost.localdomain ([2804:7f0:4841:2841:2c21:ec8a:30f3:55a6]) by smtp.gmail.com with ESMTPSA id r35sm7364575qtd.95.2021.03.22.06.22.07 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Mar 2021 06:22:08 -0700 (PDT) From: Luis Machado To: gdb-patches@sourceware.org Subject: [PATCH v6 23/25] Document new "x" and "print" memory tagging extensions Date: Mon, 22 Mar 2021 10:21:17 -0300 Message-Id: <20210322132120.1202230-24-luis.machado@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210322132120.1202230-1-luis.machado@linaro.org> References: <20210322132120.1202230-1-luis.machado@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-12.6 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: Mon, 22 Mar 2021 13:22:10 -0000 Updates on v6 - Document the new memory-tag-violation print option. -- 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 | 42 +++++++++++++++++++++++++++++++++++++++--- 1 file changed, 39 insertions(+), 3 deletions(-) diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index d976325e695..dbf878cdbc3 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -9951,6 +9951,10 @@ 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}. @@ -10718,7 +10722,8 @@ 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}. @@ -10813,6 +10818,22 @@ 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 @@ -10890,8 +10911,9 @@ If the underlying architecture supports memory tagging, like AArch64 MTE or SPARC ADI do, @value{GDBN} can make use of it to validate pointers against memory allocation tags. -A command prefix of @code{memory-tag} 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{memory-tag} gives access to the various memory tagging commands. The @code{memory-tag} commands are the following: @@ -11527,6 +11549,20 @@ language, for most languages @code{@{...@}} is used, but Fortran uses Display the current threshold after which nested structures are replaces with ellipsis. +@anchor{set print memory-tag-violations} +@cindex printing memory tag violation information +@item set print memory-tag-violations +@itemx set print memory-tag-violations on +Cause @value{GDBN} to display additional information about memory tag violations +when printing pointers and addresses. + +@item set print memory-tag-violations off +Stop printing memory tag violation information. + +@item show print memory-tag-violations +Show whether memory tag violation information is displayed when printing +pointers and addresses. + @anchor{set print null-stop} @item set print null-stop @cindex @sc{null} elements in arrays -- 2.25.1