From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-x742.google.com (mail-qk1-x742.google.com [IPv6:2607:f8b0:4864:20::742]) by sourceware.org (Postfix) with ESMTPS id 08E6B3857015 for ; Wed, 15 Jul 2020 19:46:33 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 08E6B3857015 Received: by mail-qk1-x742.google.com with SMTP id e13so3026362qkg.5 for ; Wed, 15 Jul 2020 12:46:33 -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=KaVlz5L4tzg2v8IBbT3AjfQCa5ukpfcu7HxUd6VixrM=; b=iH2LJgPRoak1fo4bwFAwuzrUopO/RroNPDcYUKRcGKRrjB+sIhesTeYJNm68Gv3WLf nvwSHw5J/rcNhFi08Yp8J91u1gU1ohTDQ6qSdcPeYXFo40kPjexMgQ0DvI7viPnYwnO6 PxZFWFoSEzIIjL7kuoOWzT8MkfEOY7aLYmXyN48j/hfIXzUtcJkdszFgd7hPA85WdEed WE+/cYA73ZVFpZ8niVNSsdsUbyo4QxuSL+6768nRRRYx57D64pLRPeBBWgfUIWZmCy7V ITuhLAPkf6C8iN+QwWBXop3MKKXydzjBDtAEs9eWrXfdJ1P8M4a9l6H4rpP2xy6ZOHbp tiuQ== X-Gm-Message-State: AOAM5333alV5s7rT4DVX7MEcwQJzJ0QnEUftWx+GWM9vlx0HSFzuyRdk WtjnjHMZbMFfFfK9P/PhpjrZr0nRf+oD+A== X-Google-Smtp-Source: ABdhPJzF1jT0NlSkwvnG/uHl6eDGDBVs5oFndmtCT5kqclwtCG4adL6qvWsX0AxIIy0wtpIIRIE+ug== X-Received: by 2002:a37:689:: with SMTP id 131mr665704qkg.468.1594842392320; Wed, 15 Jul 2020 12:46:32 -0700 (PDT) Received: from localhost.localdomain ([2804:7f0:8283:82c3:9daa:7611:ebe6:931]) by smtp.gmail.com with ESMTPSA id z18sm4340537qta.51.2020.07.15.12.46.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Jul 2020 12:46:31 -0700 (PDT) From: Luis Machado To: gdb-patches@sourceware.org, Alan.Hayward@arm.com Cc: omair.javaid@linaro.org, catalin.marinas@arm.com, david.spickett@linaro.org, jose.marchesi@oracle.com Subject: [PATCH 03/23] Add GDB-side remote target support for memory tagging Date: Wed, 15 Jul 2020 16:44:53 -0300 Message-Id: <20200715194513.16641-4-luis.machado@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200715194513.16641-1-luis.machado@linaro.org> References: <20200715194513.16641-1-luis.machado@linaro.org> X-Spam-Status: No, score=-10.2 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: Wed, 15 Jul 2020 19:46:34 -0000 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_atags and store_atags. 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 from the address range [
,
) QMemTags:
:: -- Writes the tags 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_fmemtags_request, parse_fmemtags_reply) (create_smemtags_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 | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 106 insertions(+), 1 deletion(-) diff --git a/gdb/remote.c b/gdb/remote.c index 3e36c8a233..7a3f272995 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -2103,6 +2103,10 @@ 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 }; @@ -2244,6 +2248,14 @@ remote_exec_event_p (struct remote_state *rs) return packet_support (PACKET_exec_event_feature) == PACKET_ENABLE; } +/* Returns true if memory tagging is supported. */ + +static bool +remote_memory_tagging_p (void) +{ + 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. */ @@ -5245,6 +5257,8 @@ 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; @@ -5339,6 +5353,10 @@ 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 @@ -14393,7 +14411,63 @@ set_range_stepping (const char *ignore_args, int from_tty, bool remote_target::supports_memory_tagging () { - return false; + return remote_memory_tagging_p (); +} + +/* Create the qMemTags packet given ADDRESS and LEN. + + Return 0 if successful, non-zero otherwise. */ + +static void +create_fmemtags_request (gdb::char_vector &packet, CORE_ADDR address, + size_t len) +{ + int addr_size = gdbarch_addr_bit (target_gdbarch ()) / 8; + + std::string request = string_printf ("qMemTags:%s,%s", + phex_nz (address, addr_size), + phex_nz (len, sizeof (len))); + + strcpy (packet.data (), request.c_str ()); +} + +/* Parse the qMemTags packet reply into TAGS. + + Return 0 if successful, non-zero otherwise. */ + +static int +parse_fmemtags_reply (gdb::char_vector &reply, gdb::byte_vector &tags) +{ + if (reply.empty () || reply[0] == 'E' || reply[0] != 'm') + return 1; + + /* Copy the tag data. */ + tags = hex2bin (reply.data () + 1); + + return 0; +} + +/* Create the QMemTags packet given ADDRESS, LEN and TAGS. + + Return 0 if successful, non-zero otherwise. */ + +static void +create_smemtags_request (gdb::char_vector &packet, CORE_ADDR address, + size_t len, 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:", + phex_nz (address, addr_size), + phex_nz (len, sizeof (len))); + 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. */ @@ -14402,6 +14476,19 @@ int remote_target::fetch_memtags (CORE_ADDR address, size_t len, gdb::byte_vector &tags) { + /* 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_fmemtags_request (rs->buf, address, len); + + putpkt (rs->buf); + getpkt (&rs->buf, 0); + + parse_fmemtags_reply (rs->buf, tags); + return 0; } @@ -14411,6 +14498,21 @@ int remote_target::store_memtags (CORE_ADDR address, size_t len, const gdb::byte_vector &tags) { + /* 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_smemtags_request (rs->buf, address, len, tags); + + putpkt (rs->buf); + getpkt (&rs->buf, 0); + + /* Verify if the request was successful. */ + if (packet_check_result (rs->buf.data ()) != PACKET_OK) + return 1; + return 0; } @@ -14813,6 +14915,9 @@ 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. */ { -- 2.17.1