From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id ACRRML92qV/vbwAAWB0awg (envelope-from ) for ; Mon, 09 Nov 2020 12:05:03 -0500 Received: by simark.ca (Postfix, from userid 112) id 2BB961F08B; Mon, 9 Nov 2020 12:05:02 -0500 (EST) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=0.2 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,RDNS_NONE,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.2 Received: from sourceware.org (unknown [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 0213C1E552 for ; Mon, 9 Nov 2020 12:05:02 -0500 (EST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 8BEFD3896C1B; Mon, 9 Nov 2020 17:05:01 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 8BEFD3896C1B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1604941501; bh=mUwEr2mDMaOR79pgtVDeHvhBSfcQTxuUv3EYB8B+R1g=; 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=U6WBp0uTWK1w/c9bda4r/BIvMljLjVXJL96xNz2zA/WQ2rUafjCoqH2vORYSXv8G5 WFnNX5SXgi/Mj+G4Plqgh4jSABv+Gd9+tNRHnEyWBjB47wHdA75o4ITrep2c/8l46B r/1Y/By21DFpmD4U5LZgT/jUuC/714Zy0awYHoy8= Received: from mail-qk1-x743.google.com (mail-qk1-x743.google.com [IPv6:2607:f8b0:4864:20::743]) by sourceware.org (Postfix) with ESMTPS id 09CD33896C13 for ; Mon, 9 Nov 2020 17:04:59 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 09CD33896C13 Received: by mail-qk1-x743.google.com with SMTP id l2so8602092qkf.0 for ; Mon, 09 Nov 2020 09:04:59 -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; bh=mUwEr2mDMaOR79pgtVDeHvhBSfcQTxuUv3EYB8B+R1g=; b=mx1V980QR9FoU9dK0wKee6Whs1NeWvxKsdNBivmchgIworpKEuRR2Sbho7JT/fsy2g 3pIpOCuvrRVIf11TP6F9pRanj6rrtM913pfkQ/fz1Sz+0xKNQ/ubObSrKcOYP+t/8BUp QRwe9YQ6uvEn9S4ZwFssiOz3XStEFp/RkHYsRczPUwiwOBtrKoPuM9Meg7XcPEsVflvl cRpBtx0vemEbP4wCBKCJEPUxE0hbQEUg4EVx3Om4uvMtTxDfyCwduGftQOX2mnAi+cvL 3rVdO3GGcsn92z3rre8VqO0tuV41rQFEgQLv24UERXMNS/tAIPNwuMbqXKczq6gNwzou 8dYA== X-Gm-Message-State: AOAM53099EBrBnhoQaJ+6fNUCbp2JFPAdHD3VL/UMCM+suG1EbGmUsvT xaLvKL+FigB47HvETK5VR1LCNJHRM6ogrQ== X-Google-Smtp-Source: ABdhPJw75xN5gYhUGHuBaAkjROtY/xY+5GqAaqQ4KI2DPwn0gwjWXld3eO+ds1wfkuMFYjIk4oZeOA== X-Received: by 2002:a05:620a:11a4:: with SMTP id c4mr5093291qkk.8.1604941498169; Mon, 09 Nov 2020 09:04:58 -0800 (PST) Received: from localhost.localdomain ([2804:7f0:8284:1487:5c3b:b268:ad95:5f37]) by smtp.gmail.com with ESMTPSA id s2sm5948358qtw.44.2020.11.09.09.04.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Nov 2020 09:04:57 -0800 (PST) To: gdb-patches@sourceware.org Subject: [PATCH v3 07/24] Documentation for memory tagging remote packets Date: Mon, 9 Nov 2020 14:04:18 -0300 Message-Id: <20201109170435.15766-8-luis.machado@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201109170435.15766-1-luis.machado@linaro.org> References: <20201109170435.15766-1-luis.machado@linaro.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: , 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 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. --- gdb/doc/gdb.texinfo | 96 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 5270156000..7593559331 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -40884,6 +40884,87 @@ 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 typeis 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 @@ -41551,6 +41632,11 @@ 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: @@ -41765,6 +41851,16 @@ 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:: -- 2.17.1