From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-x72d.google.com (mail-qk1-x72d.google.com [IPv6:2607:f8b0:4864:20::72d]) by sourceware.org (Postfix) with ESMTPS id A84B33857027 for ; Mon, 22 Mar 2021 13:21:42 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A84B33857027 Received: by mail-qk1-x72d.google.com with SMTP id v70so10434654qkb.8 for ; Mon, 22 Mar 2021 06:21:42 -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=R6R2QYsYfvqyzVciM+q0fW/5P02p4GR+d0OQZrPtB4s=; b=sPnhwl5LpeXPxHw5XDFAgOjW51k0bm1nR4jbqXO7l5DyP4c4dMt7lTzfNfVXGK0NGi vosV2C/4jDzWlEhu/j+dPB+4Fh7R4Y5mqgSqyrxTA3n70ozorKEKSYjs8+bFlhQIB/fc +FcBI4APBnT7uin5pAaajit+dvJnX12URKFjEIMZBilQ1ZgqI0CHJ3CRbT2nHsMPkjq0 aYr90Mh8AJ+2cOhfF0qhI0BM6ngTiTXzAOB8g7mB3+luc6x5snh1DtZp/wsqG/q2TNyx 9Lblo9Aj5liFtP4D3YXef6GsCJb15UcQS6quLGKiMWSenKMOauudZ030BasPgr8aaY0g rp1w== X-Gm-Message-State: AOAM532NZ2NDK1Ayk5b1tg1QTnGXuirQd74fkSBnvjJcNnMNXk3aaaJ4 khKaZDsfmTa4sBjueRX3Q95Ep9ymN/+bDQ== X-Google-Smtp-Source: ABdhPJzWy+yDgGYNUua32PR3tgbnlx7Aw6exMHEPvCuf/YNtJUtu+Xlc4vXIx6ZNnFUU6lmtOelLuA== X-Received: by 2002:a05:620a:16ad:: with SMTP id s13mr8165qkj.68.1616419302135; Mon, 22 Mar 2021 06:21:42 -0700 (PDT) Received: from localhost.localdomain ([2804:7f0:4841:2841:2c21:ec8a:30f3:55a6]) by smtp.gmail.com with ESMTPSA id r35sm7364575qtd.95.2021.03.22.06.21.40 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Mar 2021 06:21:41 -0700 (PDT) From: Luis Machado To: gdb-patches@sourceware.org Subject: [PATCH v6 07/25] Documentation for memory tagging remote packets Date: Mon, 22 Mar 2021 10:21:01 -0300 Message-Id: <20210322132120.1202230-8-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=-12.4 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 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 13:21:44 -0000 Updates on v4: - Add documentation for ARM-specific memory tag types. Updates on v3: - Made packet description more clear. - Fixed Misc formatting/references issues. Updates on v2: - Update documentation to mention the packet's type field. -- Document the remote packet changes to support memory tagging. gdb/doc/ChangeLog: YYYY-MM-DD Luis Machado * gdb.texinfo (General Query Packets): Document qMemTags and QMemTags. Document the "memory-tagging" feature. (ARM-Specific Protocol Details): Document memory tag types. --- gdb/doc/gdb.texinfo | 114 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 80ccf74a049..e26ce4e9b6b 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -40992,6 +40992,87 @@ is a sequence of thread IDs, @var{threadid} (eight hex digits), from the target. See @code{remote.c:parse_threadlist_response()}. @end table +@item qMemTags:@var{start address},@var{length}:@var{type} +@anchor{qMemTags} +@cindex fetch memory tags +@cindex @samp{qMemTags} packet +Fetch memory tags of type @var{type} from the address range +@w{@r{[}@var{start address}, @var{start address} + @var{length}@r{)}}. The +target is responsible for calculating how many tags will be returned, as this +is architecture-specific. + +@var{start address} is the starting address of the memory range. + +@var{length} is the length, in bytes, of the memory range. + +@var{type} is the type of tag the request wants to fetch. The type is a signed +integer. + +Reply: +@table @samp +@item @var{mxx}@dots{} +Hex encoded sequence of uninterpreted bytes, @var{xx}@dots{}, representing the +tags found in the requested memory range. + +@item E @var{nn} +An error occured. This means that fetching of memory tags failed for some +reason. + +@item @w{} +An empty reply indicates that @samp{qMemTags} is not supported by the stub, +although this should not happen given @value{GDBN} will only send this packet +if the stub has advertised support for memory tagging via @samp{qSupported}. +@end table + +@item QMemTags:@var{start address},@var{length}:@var{type}:@var{tag bytes} +@anchor{QMemTags} +@cindex store memory tags +@cindex @samp{QMemTags} packet +Store memory tags of type @var{type} to the address range +@w{@r{[}@var{start address}, @var{start address} + @var{length}@r{)}}. The +target is responsible for interpreting the type, the tag bytes and modifying +the memory tag granules accordingly, given this is architecture-specific. + +The interpretation of how many tags (@var{nt}) should be written to how many +memory tag granules (@var{ng}) is also architecture-specific. The behavior is +implementation-specific, but the following is suggested. + +If the number of memory tags, @var{nt}, is greater than or equal to the +number of memory tag granules, @var{ng}, only @var{ng} tags will be +stored. + +If @var{nt} is less than @var{ng}, the behavior is that of a fill operation, +and the tag bytes will be used as a pattern that will get repeated until +@var{ng} tags are stored. + +@var{start address} is the starting address of the memory range. The address +does not have any restriction on alignment or size. + +@var{length} is the length, in bytes, of the memory range. + +@var{type} is the type of tag the request wants to fetch. The type is a signed +integer. + +@var{tag bytes} is a sequence of hex encoded uninterpreted bytes which will be +interpreted by the target. Each pair of hex digits is interpreted as a +single byte. + +Reply: +@table @samp +@item OK +The request was successful and the memory tag granules were modified +accordingly. + +@item E @var{nn} +An error occured. This means that modifying the memory tag granules failed +for some reason. + +@item @w{} +An empty reply indicates that @samp{QMemTags} is not supported by the stub, +although this should not happen given @value{GDBN} will only send this packet +if the stub has advertised support for memory tagging via @samp{qSupported}. +@end table + @item qOffsets @cindex section offsets, remote request @cindex @samp{qOffsets} packet @@ -41659,6 +41740,11 @@ These are the currently defined stub features and their properties: @tab @samp{-} @tab No +@item @samp{memory-tagging} +@tab No +@tab @samp{-} +@tab No + @end multitable These are the currently defined stub features, in more detail: @@ -41873,6 +41959,16 @@ The remote stub understands the @samp{QThreadEvents} packet. @item no-resumed The remote stub reports the @samp{N} stop reply. + +@item memory-tagging +The remote stub supports and implements the required memory tagging +functionality and understands the @samp{qMemTags} (@pxref{qMemTags}) and +@samp{QMemTags} (@pxref{QMemTags}) packets. + +For AArch64 GNU/Linux systems, this feature also requires access to the +@file{/proc/@var{pid}/smaps} file so memory mapping page flags can be inspected. +This is done via the @samp{vFile} requests. + @end table @item qSymbol:: @@ -42354,6 +42450,7 @@ details of XML target descriptions for each architecture. @menu * ARM Breakpoint Kinds:: +* ARM Memory Tag Types:: @end menu @node ARM Breakpoint Kinds @@ -42375,6 +42472,23 @@ These breakpoint kinds are defined for the @samp{Z0} and @samp{Z1} packets. @end table +@node ARM Memory Tag Types +@subsubsection @acronym{ARM} Memory Tag Types +@cindex memory tag types, @acronym{ARM} + +These memory tag types are defined for the @samp{qMemTag} and @samp{QMemTag} +packets. + +@table @r + +@item 0 +MTE logical tag + +@item 1 +MTE allocation tag + +@end table + @node MIPS-Specific Protocol Details @subsection @acronym{MIPS}-specific Protocol Details -- 2.25.1