From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk1-x741.google.com (mail-qk1-x741.google.com [IPv6:2607:f8b0:4864:20::741]) by sourceware.org (Postfix) with ESMTPS id 2C7873857015 for ; Wed, 15 Jul 2020 19:48:44 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 2C7873857015 Received: by mail-qk1-x741.google.com with SMTP id c139so3010557qkg.12 for ; Wed, 15 Jul 2020 12:48:44 -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=eZlawf+XQ836czV0TmLbgobtu520yNcxVzwZ69kd1ig=; b=pga9ARxI3ze+qhg1wbij9UB2ygIupgYRMFG1Lsfn8vYeBvx5JxpkuNVkoV0nhqCQxR 8rhDgnCUqS6jYea4XCwJ6HYhFDDxODnIO82QvGsLXRUQr3qSornOuMENgBOqJ2Qa5UMy NfLvJYe56zCnMlT5iQ8l7FQ4rg+lQrkxxqmCGq5Nlcppc9btyV5pNaOSwf3Yp9TOerup znjzMaaxGgLMFLvw857RPfXDHbmoFUe5zU7P8MSDSOv95lnxnSdHyXMdJep+J5mrXUUw CI7IScqZNg8QZ13DF2y4CMBpVB0iubbyHsOVJ3M/vjrKJpWkFMI5YQNISBl12nyklHYw BiYw== X-Gm-Message-State: AOAM531xCT7GsJSe09+undty8lNiKT6Ws6j5IVyIEp3rSmtPR7ofoYuf KDOn/ZRc4jMFCQ3fiFLhMC0HZGxAXRlmWA== X-Google-Smtp-Source: ABdhPJzGRPGd3L5IAigfLWfgz5Z1x+rqSHkyuqIXXTiC60nW3cS69TRv2XyQy+o8pMtLAjBi773mTA== X-Received: by 2002:a37:a68a:: with SMTP id p132mr744439qke.184.1594842523324; Wed, 15 Jul 2020 12:48:43 -0700 (PDT) Received: from localhost.localdomain ([2804:7f0:8283:82c3:9daa:7611:ebe6:931]) by smtp.gmail.com with ESMTPSA id z18sm4340537qta.51.2020.07.15.12.48.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Jul 2020 12:48:42 -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 14/23] AArch64: Implement the memory tagging gdbarch hooks Date: Wed, 15 Jul 2020 16:45:04 -0300 Message-Id: <20200715194513.16641-15-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=-10.7 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 19:48:45 -0000 This patch implements the memory tagging gdbarch hooks for AArch64, for the MTE feature. gdb/ChangeLog: YYYY-MM-DD Luis Machado * aarch64-linux-tdep.c: Include target.h, arch-utils.h, value.h. (aarch64_linux_get_atag, aarch64_linux_tagged_address_p) (aarch64_linux_memtag_mismatch_p, aarch64_linux_set_memtags) (aarch64_linux_get_memtag, aarch64_linux_memtag_to_string): New functions. (aarch64_linux_init_abi): Initialize MTE-related gdbarch hooks. * arch/aarch64-mte-linux.c (make_ltag_bits, make_ltag) (aarch64_linux_set_ltag, aarch64_linux_get_ltag): New functions. * arch/aarch64-mte-linux.h (MTE_LOGICAL_TAG_START_BIT) (MTE_LOGICAL_MAX_VALUE): Define. (make_ltag_bits, make_ltag, aarch64_linux_set_ltag) (aarch64_linux_get_ltag): New prototype. --- gdb/aarch64-linux-tdep.c | 212 +++++++++++++++++++++++++++++++++++ gdb/arch/aarch64-mte-linux.c | 36 ++++++ gdb/arch/aarch64-mte-linux.h | 19 ++++ 3 files changed, 267 insertions(+) diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c index 53f9d9f6d2..abcd325951 100644 --- a/gdb/aarch64-linux-tdep.c +++ b/gdb/aarch64-linux-tdep.c @@ -30,6 +30,7 @@ #include "symtab.h" #include "tramp-frame.h" #include "trad-frame.h" +#include "target.h" #include "target/target.h" #include "regcache.h" @@ -46,6 +47,9 @@ #include "arch/aarch64-mte-linux.h" +#include "arch-utils.h" +#include "value.h" + /* Signal frame handling. +------------+ ^ @@ -1437,6 +1441,189 @@ aarch64_linux_gcc_target_options (struct gdbarch *gdbarch) return {}; } +/* Helper to get the allocation tag from a 64-bit ADDRESS. + + Return 0 for success and non-zero otherwise. */ + +static int +aarch64_linux_get_atag (CORE_ADDR address, CORE_ADDR *tag) +{ + gdb::byte_vector tags; + + /* Attempt to fetch the allocation tag. */ + if (target_fetch_memtags (address, 0, tags) != 0) + return 1; + + /* Only one tag should've been returned. Make sure we got exactly that. */ + gdb_assert (tags.size () == 1); + + /* Although our tags are 4 bits in size, they are stored in a + byte. */ + *tag = tags[0]; + + return 0; +} + +/* Implement the tagged_address_p gdbarch method. */ + +static bool +aarch64_linux_tagged_address_p (struct gdbarch *gdbarch, struct value *address) +{ + gdb_assert (address != nullptr); + + CORE_ADDR addr = value_as_address (address); + + /* Remove the top byte for the memory range check. */ + addr = address_significant (gdbarch, addr); + + /* Check if the page that contains ADDRESS is mapped with PROT_MTE. */ + if (!linux_address_in_memtag_page (addr)) + return false; + + /* We have a valid tag in the top byte of the 64-bit address. */ + return true; +} + +/* Implement the memtag_mismatch_p gdbarch method. */ + +static bool +aarch64_linux_memtag_mismatch_p (struct gdbarch *gdbarch, + struct value *address) +{ + gdb_assert (address != nullptr); + + /* Make sure we are dealing with a tagged address to begin with. */ + if (!aarch64_linux_tagged_address_p (gdbarch, address)) + return false; + + CORE_ADDR addr = value_as_address (address); + + /* Fetch the allocation tag for ADDRESS. */ + CORE_ADDR atag = 0; + + if (aarch64_linux_get_atag (addr, &atag) != 0) + return false; + + /* Fetch the logical tag for ADDRESS. */ + gdb_byte ltag = aarch64_linux_get_ltag (addr); + + /* Are the tags the same? */ + if (ltag == atag) + return false; + + return true; +} + +/* Implement the set_memtags gdbarch method. */ + +static int +aarch64_linux_set_memtags (struct gdbarch *gdbarch, struct value *address, + size_t length, const gdb::byte_vector &tags, + enum memtag_type tag_type) +{ + if (tags.empty ()) + return 0; + + gdb_assert (address != nullptr); + + CORE_ADDR addr = value_as_address (address); + + /* Set the logical tag or the allocation tag. */ + if (tag_type == tag_logical) + { + /* When setting logical tags, we don't care about the length, since + we are only setting a single logical tag. */ + addr = aarch64_linux_set_ltag (addr, tags[0]); + + /* Update the value's content with the tag. */ + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + gdb_byte *srcbuf = value_contents_raw (address); + store_unsigned_integer (srcbuf, sizeof (addr), byte_order, addr); + } + else + { + /* Make sure we are dealing with a tagged address to begin with. */ + if (!aarch64_linux_tagged_address_p (gdbarch, address)) + return 1; + + /* With G being the number of tag granules and N the number of tags + passed in, we can have the following cases: + + 1 - G == N: Store all the N tags to memory. + + 2 - G < N : Warn about having more tags than granules, but write G + tags. + + 3 - G > N : This is a "fill tags" operation. We should use the tags + as a pattern to fill the granules repeatedly until we have + written G tags to memory. + */ + + size_t g = get_tag_granules (addr, length, MTE_GRANULE_SIZE); + size_t n = tags.size (); + + if (g < n) + { + warning (_("Got more tags than memory granules. Tags will be " + "truncated.")); + } + else if (g > n) + warning (_("Using tag pattern to fill memory range.")); + + if (target_store_memtags (addr, length, tags) != 0) + return 1; + } + return 0; +} + +/* Implement the get_memtag gdbarch method. */ + +static struct value * +aarch64_linux_get_memtag (struct gdbarch *gdbarch, struct value *address, + enum memtag_type tag_type) +{ + gdb_assert (address != nullptr); + + CORE_ADDR addr = value_as_address (address); + CORE_ADDR tag = 0; + + /* Get the logical tag or the allocation tag. */ + if (tag_type == tag_logical) + tag = aarch64_linux_get_ltag (addr); + else + { + /* Make sure we are dealing with a tagged address to begin with. */ + if (!aarch64_linux_tagged_address_p (gdbarch, address)) + return nullptr; + + if (aarch64_linux_get_atag (addr, &tag) != 0) + return nullptr; + } + + /* Convert the tag to a value. */ + return value_from_ulongest (builtin_type (gdbarch)->builtin_unsigned_int, + tag); +} + +/* Implement the memtag_to_string gdbarch method. */ + +static std::string +aarch64_linux_memtag_to_string (struct gdbarch *gdbarch, + struct value *address, + enum memtag_type tag_type) +{ + gdb_assert (address != nullptr); + + struct value *v_tag = aarch64_linux_get_memtag (gdbarch, address, tag_type); + + if (v_tag == nullptr && tag_allocation) + error (_("Error getting tag from target")); + + CORE_ADDR tag = value_as_address (v_tag); + + return string_printf ("0x%s", phex_nz (tag, sizeof (tag))); +} + static void aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { @@ -1494,6 +1681,31 @@ aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) data associated with the address. */ set_gdbarch_significant_addr_bit (gdbarch, 56); + /* MTE-specific settings and hooks. */ + if (tdep->has_mte ()) + { + /* Register a hook for checking if an address is tagged or not. */ + set_gdbarch_tagged_address_p (gdbarch, aarch64_linux_tagged_address_p); + + /* Register a hook for checking if there is a memory tag mismatch. */ + set_gdbarch_memtag_mismatch_p (gdbarch, + aarch64_linux_memtag_mismatch_p); + + /* Register a hook for setting the logical/allocation tags for + a range of addresses. */ + set_gdbarch_set_memtags (gdbarch, aarch64_linux_set_memtags); + + /* Register a hook for extracting the logical/allocation tag from an + address. */ + set_gdbarch_get_memtag (gdbarch, aarch64_linux_get_memtag); + + /* Set the allocation tag granule size to 16 bytes. */ + set_gdbarch_memtag_granule_size (gdbarch, MTE_GRANULE_SIZE); + + /* Register a hook for converting a memory tag to a string. */ + set_gdbarch_memtag_to_string (gdbarch, aarch64_linux_memtag_to_string); + } + /* Initialize the aarch64_linux_record_tdep. */ /* These values are the size of the type that will be used in a system call. They are obtained from Linux Kernel source. */ diff --git a/gdb/arch/aarch64-mte-linux.c b/gdb/arch/aarch64-mte-linux.c index ee162aef19..5c02e5ef5b 100644 --- a/gdb/arch/aarch64-mte-linux.c +++ b/gdb/arch/aarch64-mte-linux.c @@ -32,3 +32,39 @@ get_tag_granules (CORE_ADDR addr, size_t len, size_t granule_size) /* We always have at least 1 granule. */ return 1 + (e_addr - s_addr) / granule_size; } + +/* See arch/aarch64-mte-linux.h */ + +CORE_ADDR +make_ltag_bits (CORE_ADDR value) +{ + return value & MTE_LOGICAL_MAX_VALUE; +} + +/* See arch/aarch64-mte-linux.h */ + +CORE_ADDR +make_ltag (CORE_ADDR value) +{ + return make_ltag_bits (value) << MTE_LOGICAL_TAG_START_BIT; +} + +/* See arch/aarch64-mte-linux.h */ + +CORE_ADDR +aarch64_linux_set_ltag (CORE_ADDR address, CORE_ADDR tag) +{ + /* Remove the existing tag. */ + address &= ~make_ltag (MTE_LOGICAL_MAX_VALUE); + + /* Return the new tagged address. */ + return address | make_ltag (tag); +} + +/* See arch/aarch64-mte-linux.h */ + +CORE_ADDR +aarch64_linux_get_ltag (CORE_ADDR address) +{ + return make_ltag_bits (address >> MTE_LOGICAL_TAG_START_BIT); +} diff --git a/gdb/arch/aarch64-mte-linux.h b/gdb/arch/aarch64-mte-linux.h index e555f0af19..5c5783f28b 100644 --- a/gdb/arch/aarch64-mte-linux.h +++ b/gdb/arch/aarch64-mte-linux.h @@ -32,10 +32,29 @@ /* We have one tag per 16 bytes of memory. */ #define MTE_GRANULE_SIZE 16 +#define MTE_LOGICAL_TAG_START_BIT 56 +#define MTE_LOGICAL_MAX_VALUE 0xf /* Return the number of tag granules in the memory range [ADDR, ADDR + LEN) given GRANULE_SIZE. */ extern size_t get_tag_granules (CORE_ADDR addr, size_t len, size_t granule_size); +/* Return the 4-bit tag made from VALUE. */ +extern CORE_ADDR make_ltag_bits (CORE_ADDR value); + +/* Return the 4-bit tag that can be OR-ed to an address. */ +extern CORE_ADDR make_ltag (CORE_ADDR value); + +/* Helper to set the logical TAG for a 64-bit ADDRESS. + + It is always possible to set the logical tag. */ +extern CORE_ADDR aarch64_linux_set_ltag (CORE_ADDR address, + CORE_ADDR tag); + +/* Helper to get the logical tag from a 64-bit ADDRESS. + + It is always possible to get the logical tag. */ +extern CORE_ADDR aarch64_linux_get_ltag (CORE_ADDR address); + #endif /* ARCH_AARCH64_LINUX_H */ -- 2.17.1