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 6B66B3857036 for ; Mon, 22 Mar 2021 13:21:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 6B66B3857036 Received: by mail-qk1-x72d.google.com with SMTP id q3so10426548qkq.12 for ; Mon, 22 Mar 2021 06:21:36 -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=+ToOrTfxEIh7AjLGUeZ0Yy8Zdn3GycJBqHN4b9vhOM0=; b=sai2TUpgpj0deG3CX5zu6R8Ch+aEF4SHlJ3fENUaeBS9SDpyv0QGg5CvVyu5QC2kTF 79xtfryjq1To6hH9uJlDxoUivszBtAogrLYxdczHj/I4EUY0fFE7l/RljwEIr8l8/I7r 9N4KOSo9ZcI/v95+LX5ynsYBFmzfW5b18qwaA2E/GYBrrJH5EABCAgukWFpmJsNgwwhY Cpy3EUwF0CNfLR3lo0rSHdNDHg9EkMOA52N8UWzddP92FnNMi6r1224MP9xEuyFon5qC EUurfAfe4x7Rj4xVA6C81YZEMj3ne9s3d/YCh30QPxHS+yCXHBJ4XmrVUmyunbiFvk3k veWQ== X-Gm-Message-State: AOAM531jmW4RJlLXbWNyamOOYgfRcmRlkE8rOJ8nT2PcrklfLe5fud5v k9lRrMIoVuttA+JriqOy34ucRtZTQVgfFQ== X-Google-Smtp-Source: ABdhPJwomsi+RqsirAF5W5KnCPSiHVevjltSqooVJGCbn8Ud7FhmPMlCMFVRC7NFOrjinXbS+G/HCA== X-Received: by 2002:a37:6888:: with SMTP id d130mr10607774qkc.368.1616419295877; Mon, 22 Mar 2021 06:21:35 -0700 (PDT) Received: from localhost.localdomain ([2804:7f0:4841:2841:2c21:ec8a:30f3:55a6]) by smtp.gmail.com with ESMTPSA id r35sm7364575qtd.95.2021.03.22.06.21.34 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Mar 2021 06:21:35 -0700 (PDT) From: Luis Machado To: gdb-patches@sourceware.org Subject: [PATCH v6 03/25] Add GDB-side remote target support for memory tagging Date: Mon, 22 Mar 2021 10:20:57 -0300 Message-Id: <20210322132120.1202230-4-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=-12.2 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 13:21:38 -0000 Updates for v6: - Removed void parameter. - Adjusted commit message. Updates for v4: - Rename RSP helper functions. - Fixup parameter and return types. Updates for v2: - Add type field to target hooks. - Add type data to qMemTags and QMemTags. The packets now look like this: qMemTags:
,: QMemTags:
,:: -- This patch adds memory tagging support to GDB's remote side, with packet string checks, new packet support and an implementation of the two new tags methods fetch_memtags and store_memtags. GDBserver needs to know how to read/write allocation tags, since that is done via ptrace. It doesn't need to know about logical tags. The new packets are: qMemTags:
,: -- Reads tags of the specified type from the address range [
,
) QMemTags:
,:: -- Writes the tags of specified type represented by the uninterpreted bytes to the address range [
,
). The interpretation of what to do with the tag bytes is up to the arch-specific code. Note that these new packets consider the case of packet size overflow as an error, given the common use case is to read/write only a few memory tags at a time. Having to use a couple new packets for multi-part transfers wouldn't make sense for the little use it would have. gdb/ChangeLog: YYYY-MM-DD Luis Machado * remote.c (PACKET_memory_tagging_feature): New enum. (remote_memory_tagging_p): New function. (remote_protocol_features): New "memory-tagging" entry. (remote_target::remote_query_supported): Handle memory tagging support. (remote_target::supports_memory_tagging): Implement. (create_fetch_memtags_request, parse_fetch_memtags_reply) (create_store_memtags_request): New functions. (remote_target::fetch_memtags): Implement. (remote_target::store_memtags): Implement. (_initialize_remote): Add new "memory-tagging-feature" config command. --- gdb/remote.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 103 insertions(+), 3 deletions(-) diff --git a/gdb/remote.c b/gdb/remote.c index 49c49993762..5131d78747f 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -2175,6 +2175,10 @@ enum { /* Support TARGET_WAITKIND_NO_RESUMED. */ PACKET_no_resumed, + /* Support for memory tagging, allocation tag fetch/store + packets and the tag violation stop replies. */ + PACKET_memory_tagging_feature, + PACKET_MAX }; @@ -2316,6 +2320,14 @@ remote_exec_event_p (struct remote_state *rs) return packet_support (PACKET_exec_event_feature) == PACKET_ENABLE; } +/* Returns true if memory tagging is supported, false otherwise. */ + +static bool +remote_memory_tagging_p () +{ + return packet_support (PACKET_memory_tagging_feature) == PACKET_ENABLE; +} + /* Insert fork catchpoint target routine. If fork events are enabled then return success, nothing more to do. */ @@ -5315,6 +5327,8 @@ static const struct protocol_feature remote_protocol_features[] = { { "vContSupported", PACKET_DISABLE, remote_supported_packet, PACKET_vContSupported }, { "QThreadEvents", PACKET_DISABLE, remote_supported_packet, PACKET_QThreadEvents }, { "no-resumed", PACKET_DISABLE, remote_supported_packet, PACKET_no_resumed }, + { "memory-tagging", PACKET_DISABLE, remote_supported_packet, + PACKET_memory_tagging_feature }, }; static char *remote_support_xml; @@ -5409,6 +5423,10 @@ remote_target::remote_query_supported () if (packet_set_cmd_state (PACKET_no_resumed) != AUTO_BOOLEAN_FALSE) remote_query_supported_append (&q, "no-resumed+"); + if (packet_set_cmd_state (PACKET_memory_tagging_feature) + != AUTO_BOOLEAN_FALSE) + remote_query_supported_append (&q, "memory-tagging+"); + /* Keep this one last to work around a gdbserver <= 7.10 bug in the qSupported:xmlRegisters=i386 handling. */ if (remote_support_xml != NULL @@ -14502,7 +14520,63 @@ show_remote_timeout (struct ui_file *file, int from_tty, bool remote_target::supports_memory_tagging () { - return false; + return remote_memory_tagging_p (); +} + +/* Create the qMemTags packet given ADDRESS, LEN and TYPE. */ + +static void +create_fetch_memtags_request (gdb::char_vector &packet, CORE_ADDR address, + size_t len, int type) +{ + int addr_size = gdbarch_addr_bit (target_gdbarch ()) / 8; + + std::string request = string_printf ("qMemTags:%s,%s:%s", + phex_nz (address, addr_size), + phex_nz (len, sizeof (len)), + phex_nz (type, sizeof (type))); + + strcpy (packet.data (), request.c_str ()); +} + +/* Parse the qMemTags packet reply into TAGS. + + Return true if successful, false otherwise. */ + +static bool +parse_fetch_memtags_reply (const gdb::char_vector &reply, + gdb::byte_vector &tags) +{ + if (reply.empty () || reply[0] == 'E' || reply[0] != 'm') + return false; + + /* Copy the tag data. */ + tags = hex2bin (reply.data () + 1); + + return true; +} + +/* Create the QMemTags packet given ADDRESS, LEN, TYPE and TAGS. */ + +static void +create_store_memtags_request (gdb::char_vector &packet, CORE_ADDR address, + size_t len, int type, + const gdb::byte_vector &tags) +{ + int addr_size = gdbarch_addr_bit (target_gdbarch ()) / 8; + + /* Put together the main packet, address and length. */ + std::string request = string_printf ("QMemTags:%s,%s:%s:", + phex_nz (address, addr_size), + phex_nz (len, sizeof (len)), + phex_nz (type, sizeof (type))); + request += bin2hex (tags.data (), tags.size ()); + + /* Check if we have exceeded the maximum packet size. */ + if (packet.size () < request.length ()) + error (_("Contents too big for packet QMemTags.")); + + strcpy (packet.data (), request.c_str ()); } /* Implement the "fetch_memtags" target_ops method. */ @@ -14511,7 +14585,18 @@ bool remote_target::fetch_memtags (CORE_ADDR address, size_t len, gdb::byte_vector &tags, int type) { - return false; + /* Make sure the qMemTags packet is supported. */ + if (!remote_memory_tagging_p ()) + gdb_assert_not_reached ("remote fetch_memtags called with packet disabled"); + + struct remote_state *rs = get_remote_state (); + + create_fetch_memtags_request (rs->buf, address, len, type); + + putpkt (rs->buf); + getpkt (&rs->buf, 0); + + return parse_fetch_memtags_reply (rs->buf, tags); } /* Implement the "store_memtags" target_ops method. */ @@ -14520,7 +14605,19 @@ bool remote_target::store_memtags (CORE_ADDR address, size_t len, const gdb::byte_vector &tags, int type) { - return false; + /* Make sure the QMemTags packet is supported. */ + if (!remote_memory_tagging_p ()) + gdb_assert_not_reached ("remote store_memtags called with packet disabled"); + + struct remote_state *rs = get_remote_state (); + + create_store_memtags_request (rs->buf, address, len, type, tags); + + putpkt (rs->buf); + getpkt (&rs->buf, 0); + + /* Verify if the request was successful. */ + return packet_check_result (rs->buf.data ()) == PACKET_OK; } void _initialize_remote (); @@ -14922,6 +15019,9 @@ Show the maximum size of the address (in bits) in a memory packet."), NULL, add_packet_config_cmd (&remote_protocol_packets[PACKET_no_resumed], "N stop reply", "no-resumed-stop-reply", 0); + add_packet_config_cmd (&remote_protocol_packets[PACKET_memory_tagging_feature], + "memory-tagging-feature", "memory-tagging-feature", 0); + /* Assert that we've registered "set remote foo-packet" commands for all packet configs. */ { -- 2.25.1