[PATCH, v4] [AArch64] MTE corefile support
Luis Machado
luis.machado@arm.com
Thu May 12 10:36:20 GMT 2022
ping?
On 5/3/22 22:56, Luis Machado via Gdb-patches wrote:
> v4:
>
> - Updated documentation (added cross-references).
> - Updated the segment name from PT_ARM_MEMTAG_MTE to
> PT_AARCH64_MEMTAG_MTE.
>
> v3:
>
> - Updated NEWS and documentation to be more thorough.
>
> v2:
>
> - Rework memory tag section handling to use generic section fields.
>
> --
>
> Teach GDB how to dump memory tags for AArch64 when using the gcore command
> and how to read memory tag data back from a core file generated by GDB
> (via gcore) or by the Linux kernel.
>
> The format is documented in the Linux Kernel documentation [1].
>
> Each tagged memory range (listed in /proc/<pid>/smaps) gets dumped to its
> own PT_AARCH64_MEMTAG_MTE segment. A section named ".memtag" is created for each
> of those segments when reading the core file back.
>
> To save a little bit of space, given MTE tags only take 4 bits, the memory tags
> are stored packed as 2 tags per byte.
>
> When reading the data back, the tags are unpacked.
>
> I've added a new testcase to exercise the feature.
>
> Build-tested with --enable-targets=all and regression tested on aarch64-linux
> Ubuntu 20.04.
>
> [1] Documentation/arm64/memory-tagging-extension.rst (Core Dump Support)
> ---
> gdb/Makefile.in | 1 +
> gdb/NEWS | 10 ++
> gdb/aarch64-linux-tdep.c | 167 +++++++++++++++++++
> gdb/arch/aarch64-mte-linux.c | 56 +++++++
> gdb/arch/aarch64-mte-linux.h | 10 ++
> gdb/corelow.c | 62 +++++++
> gdb/defs.h | 3 +-
> gdb/doc/gdb.texinfo | 19 +++
> gdb/gcore.c | 83 ++++++++-
> gdb/gdbarch-components.py | 35 ++++
> gdb/gdbarch-gen.h | 26 +++
> gdb/gdbarch.c | 96 +++++++++++
> gdb/linux-tdep.c | 39 ++++-
> gdb/memtag.c | 61 +++++++
> gdb/memtag.h | 50 ++++++
> gdb/testsuite/gdb.arch/aarch64-mte-gcore.c | 93 +++++++++++
> gdb/testsuite/gdb.arch/aarch64-mte-gcore.exp | 107 ++++++++++++
> 17 files changed, 910 insertions(+), 8 deletions(-)
> create mode 100644 gdb/memtag.c
> create mode 100644 gdb/memtag.h
> create mode 100644 gdb/testsuite/gdb.arch/aarch64-mte-gcore.c
> create mode 100644 gdb/testsuite/gdb.arch/aarch64-mte-gcore.exp
>
> diff --git a/gdb/Makefile.in b/gdb/Makefile.in
> index 418094775a5..fac9364bea4 100644
> --- a/gdb/Makefile.in
> +++ b/gdb/Makefile.in
> @@ -1120,6 +1120,7 @@ COMMON_SFILES = \
> memattr.c \
> memory-map.c \
> memrange.c \
> + memtag.c \
> minidebug.c \
> minsyms.c \
> mipsread.c \
> diff --git a/gdb/NEWS b/gdb/NEWS
> index 982f4a1a18c..3d925dc3663 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -3,6 +3,16 @@
>
> *** Changes since GDB 12
>
> +* GDB now supports dumping memory tag data for AArch64 MTE. It also supports
> + reading memory tag data for AArch64 MTE from core files generated by
> + the gcore command or the Linux kernel.
> +
> + When a process uses memory-mapped pages protected by memory tags (for
> + example, AArch64 MTE), this additional information will be recorded in
> + the core file in the event of a crash or if GDB generates a core file
> + from the current process state. GDB will show this additional information
> + automatically, or through one of the memory-tag subcommands.
> +
> * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
>
> * Remove support for building against Python 2, it is now only possible to
> diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c
> index 55094b3d88b..12d98e71796 100644
> --- a/gdb/aarch64-linux-tdep.c
> +++ b/gdb/aarch64-linux-tdep.c
> @@ -53,6 +53,9 @@
>
> #include "gdbsupport/selftest.h"
>
> +#include "elf/common.h"
> +#include "elf/aarch64.h"
> +
> /* Signal frame handling.
>
> +------------+ ^
> @@ -1781,6 +1784,155 @@ aarch64_linux_report_signal_info (struct gdbarch *gdbarch,
> }
> }
>
> +/* AArch64 Linux implementation of the gdbarch_create_memtag_section hook. */
> +
> +static asection *
> +aarch64_linux_create_memtag_section (struct gdbarch *gdbarch, bfd *obfd,
> + CORE_ADDR address, size_t size)
> +{
> + gdb_assert (obfd != nullptr);
> + gdb_assert (size > 0);
> +
> + /* Create the section and associated program header. */
> + asection *mte_section = bfd_make_section_anyway (obfd, "memtag");
> +
> + if (mte_section == nullptr)
> + return nullptr;
> +
> + bfd_set_section_vma (mte_section, address);
> + /* The size of the memory range covered by the memory tags. We reuse the
> + section's rawsize field for this purpose. */
> + mte_section->rawsize = size;
> + /* Tags are stored packed as 2 tags per byte. */
> + bfd_set_section_size (mte_section, (size / AARCH64_MTE_GRANULE_SIZE) / 2);
> + /* Make sure the section's flags has SEC_HAS_CONTENTS, otherwise BFD will
> + refuse to write data to this section. */
> + bfd_set_section_flags (mte_section, SEC_HAS_CONTENTS);
> +
> + /* Store program header information. */
> + bfd_record_phdr (obfd, PT_AARCH64_MEMTAG_MTE, 1, 0, 0, 0, 0, 0, 1,
> + &mte_section);
> +
> + return mte_section;
> +}
> +
> +/* Maximum number of tags to request. */
> +#define MAX_TAGS_TO_TRANSFER 1024
> +
> +/* AArch64 Linux implementation of the gdbarch_fill_memtag_section hook. */
> +
> +static bool
> +aarch64_linux_fill_memtag_section (struct gdbarch *gdbarch, asection *osec)
> +{
> + /* We only handle MTE tags for now. */
> +
> + size_t segment_size = osec->rawsize;
> + CORE_ADDR start_address = bfd_section_vma (osec);
> + CORE_ADDR end_address = start_address + segment_size;
> +
> + /* Figure out how many tags we need to store in this memory range. */
> + size_t granules = aarch64_mte_get_tag_granules (start_address, segment_size,
> + AARCH64_MTE_GRANULE_SIZE);
> +
> + /* If there are no tag granules to fetch, just return. */
> + if (granules == 0)
> + return true;
> +
> + CORE_ADDR address = start_address;
> +
> + /* Vector of tags. */
> + gdb::byte_vector tags;
> +
> + while (granules > 0)
> + {
> + /* Transfer tags in chunks. */
> + gdb::byte_vector tags_read;
> + size_t xfer_len
> + = (granules >= MAX_TAGS_TO_TRANSFER)?
> + MAX_TAGS_TO_TRANSFER * AARCH64_MTE_GRANULE_SIZE :
> + granules * AARCH64_MTE_GRANULE_SIZE;
> +
> + if (!target_fetch_memtags (address, xfer_len, tags_read,
> + static_cast<int> (memtag_type::allocation)))
> + {
> + warning (_("Failed to read MTE tags from memory range [%s,%s)."),
> + phex_nz (start_address, sizeof (start_address)),
> + phex_nz (end_address, sizeof (end_address)));
> + return false;
> + }
> +
> + /* Transfer over the tags that have been read. */
> + tags.insert (tags.end (), tags_read.begin (), tags_read.end ());
> +
> + /* Adjust the remaining granules and starting address. */
> + granules -= tags_read.size ();
> + address += tags_read.size () * AARCH64_MTE_GRANULE_SIZE;
> + }
> +
> + /* Pack the MTE tag bits. */
> + aarch64_mte_pack_tags (tags);
> +
> + if (!bfd_set_section_contents (osec->owner, osec, tags.data (),
> + 0, tags.size ()))
> + {
> + warning (_("Failed to write %s bytes of corefile memory "
> + "tag content (%s)."),
> + pulongest (tags.size ()),
> + bfd_errmsg (bfd_get_error ()));
> + }
> + return true;
> +}
> +
> +/* AArch64 Linux implementation of the gdbarch_decode_memtag_section
> + hook. Decode a memory tag section and return the requested tags.
> +
> + The section is guaranteed to cover the [ADDRESS, ADDRESS + length)
> + range. */
> +
> +static gdb::byte_vector
> +aarch64_linux_decode_memtag_section (struct gdbarch *gdbarch,
> + bfd_section *section,
> + int type,
> + CORE_ADDR address, size_t length)
> +{
> + gdb_assert (section != nullptr);
> +
> + /* The requested address must not be less than section->vma. */
> + gdb_assert (section->vma <= address);
> +
> + /* Figure out how many tags we need to fetch in this memory range. */
> + size_t granules = aarch64_mte_get_tag_granules (address, length,
> + AARCH64_MTE_GRANULE_SIZE);
> + /* Sanity check. */
> + gdb_assert (granules > 0);
> +
> + /* Fetch the total number of tags in the range [VMA, address + length). */
> + size_t granules_from_vma
> + = aarch64_mte_get_tag_granules (section->vma,
> + address - section->vma + length,
> + AARCH64_MTE_GRANULE_SIZE);
> +
> + /* Adjust the tags vector to contain the exact number of packed bytes. */
> + gdb::byte_vector tags (((granules - 1) >> 1) + 1);
> +
> + /* Figure out the starting offset into the packed tags data. */
> + file_ptr offset = ((granules_from_vma - granules) >> 1);
> +
> + if (!bfd_get_section_contents (section->owner, section, tags.data (),
> + offset, tags.size ()))
> + error (_("Couldn't read contents from memtag section."));
> +
> + /* At this point, the tags are packed 2 per byte. Unpack them before
> + returning. */
> + bool skip_first = ((granules_from_vma - granules) % 2) != 0;
> + aarch64_mte_unpack_tags (tags, skip_first);
> +
> + /* Resize to the exact number of tags that was requested. */
> + tags.resize (granules);
> +
> + return tags;
> +}
> +
> static void
> aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
> {
> @@ -1864,6 +2016,21 @@ aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
>
> set_gdbarch_report_signal_info (gdbarch,
> aarch64_linux_report_signal_info);
> +
> + /* Core file helpers. */
> +
> + /* Core file helper to create a memory tag section for a particular
> + PT_LOAD segment. */
> + set_gdbarch_create_memtag_section
> + (gdbarch, aarch64_linux_create_memtag_section);
> +
> + /* Core file helper to fill a memory tag section with tag data. */
> + set_gdbarch_fill_memtag_section
> + (gdbarch, aarch64_linux_fill_memtag_section);
> +
> + /* Core file helper to decode a memory tag section. */
> + set_gdbarch_decode_memtag_section (gdbarch,
> + aarch64_linux_decode_memtag_section);
> }
>
> /* Initialize the aarch64_linux_record_tdep. */
> diff --git a/gdb/arch/aarch64-mte-linux.c b/gdb/arch/aarch64-mte-linux.c
> index fc7a8cc00f7..3af6f364e91 100644
> --- a/gdb/arch/aarch64-mte-linux.c
> +++ b/gdb/arch/aarch64-mte-linux.c
> @@ -21,6 +21,62 @@
>
> /* See arch/aarch64-mte-linux.h */
>
> +void
> +aarch64_mte_pack_tags (gdb::byte_vector &tags)
> +{
> + /* Nothing to pack? */
> + if (tags.empty ())
> + return;
> +
> + /* If the tags vector has an odd number of elements, add another
> + zeroed-out element to make it even. This facilitates packing. */
> + if ((tags.size () % 2) != 0)
> + tags.emplace_back (0);
> +
> + for (int unpacked = 0, packed = 0; unpacked < tags.size ();
> + unpacked += 2, packed++)
> + tags[packed] = (tags[unpacked + 1] << 4) | tags[unpacked];
> +
> + /* Now we have half the size. */
> + tags.resize (tags.size () / 2);
> +}
> +
> +/* See arch/aarch64-mte-linux.h */
> +
> +void
> +aarch64_mte_unpack_tags (gdb::byte_vector &tags, bool skip_first)
> +{
> + /* Nothing to unpack? */
> + if (tags.empty ())
> + return;
> +
> + /* An unpacked MTE tags vector will have twice the number of elements
> + compared to an unpacked one. */
> + gdb::byte_vector unpacked_tags (tags.size () * 2);
> +
> + int unpacked = 0, packed = 0;
> +
> + if (skip_first)
> + {
> + /* We are not interested in the first unpacked element, just discard
> + it. */
> + unpacked_tags[unpacked] = (tags[packed] >> 4) & 0xf;
> + unpacked++;
> + packed++;
> + }
> +
> + for (; packed < tags.size (); unpacked += 2, packed++)
> + {
> + unpacked_tags[unpacked] = tags[packed] & 0xf;
> + unpacked_tags[unpacked + 1] = (tags[packed] >> 4) & 0xf;
> + }
> +
> + /* Update the original tags vector. */
> + tags = std::move (unpacked_tags);
> +}
> +
> +/* See arch/aarch64-mte-linux.h */
> +
> size_t
> aarch64_mte_get_tag_granules (CORE_ADDR addr, size_t len, size_t granule_size)
> {
> diff --git a/gdb/arch/aarch64-mte-linux.h b/gdb/arch/aarch64-mte-linux.h
> index d158926feff..8a145b447aa 100644
> --- a/gdb/arch/aarch64-mte-linux.h
> +++ b/gdb/arch/aarch64-mte-linux.h
> @@ -32,6 +32,7 @@
>
> /* We have one tag per 16 bytes of memory. */
> #define AARCH64_MTE_GRANULE_SIZE 16
> +#define AARCH64_MTE_TAG_BIT_SIZE 4
> #define AARCH64_MTE_LOGICAL_TAG_START_BIT 56
> #define AARCH64_MTE_LOGICAL_MAX_VALUE 0xf
>
> @@ -71,4 +72,13 @@ extern CORE_ADDR aarch64_mte_set_ltag (CORE_ADDR address, CORE_ADDR tag);
> It is always possible to get the logical tag. */
> extern CORE_ADDR aarch64_mte_get_ltag (CORE_ADDR address);
>
> +/* Given a TAGS vector containing 1 MTE tag per byte, pack the data as
> + 2 tags per byte and resize the vector. */
> +void aarch64_mte_pack_tags (gdb::byte_vector &tags);
> +
> +/* Given a TAGS vector containing 2 MTE tags per byte, unpack the data as
> + 1 tag per byte and resize the vector. If SKIP_FIRST is TRUE, skip the
> + first unpacked element. Otherwise leave it in the unpacked vector. */
> +void aarch64_mte_unpack_tags (gdb::byte_vector &tags, bool skip_first);
> +
> #endif /* ARCH_AARCH64_LINUX_H */
> diff --git a/gdb/corelow.c b/gdb/corelow.c
> index 8c33fb7ebb2..8b8994f80db 100644
> --- a/gdb/corelow.c
> +++ b/gdb/corelow.c
> @@ -52,6 +52,7 @@
> #include <unordered_set>
> #include "gdbcmd.h"
> #include "xml-tdesc.h"
> +#include "memtag.h"
>
> #ifndef O_LARGEFILE
> #define O_LARGEFILE 0
> @@ -101,6 +102,13 @@ class core_target final : public process_stratum_target
>
> bool info_proc (const char *, enum info_proc_what) override;
>
> + bool supports_memory_tagging () override;
> +
> + /* Core file implementation of fetch_memtags. Fetch the memory tags from
> + core file notes. */
> + bool fetch_memtags (CORE_ADDR address, size_t len,
> + gdb::byte_vector &tags, int type) override;
> +
> /* A few helpers. */
>
> /* Getter, see variable definition. */
> @@ -1162,6 +1170,60 @@ core_target::info_proc (const char *args, enum info_proc_what request)
> return true;
> }
>
> +/* Implementation of the "supports_memory_tagging" target_ops method. */
> +
> +bool
> +core_target::supports_memory_tagging ()
> +{
> + /* Look for memory tag sections. If they exist, that means this core file
> + supports memory tagging. */
> +
> + return (bfd_get_section_by_name (core_bfd, "memtag") != nullptr);
> +}
> +
> +/* Implementation of the "fetch_memtags" target_ops method. */
> +
> +bool
> +core_target::fetch_memtags (CORE_ADDR address, size_t len,
> + gdb::byte_vector &tags, int type)
> +{
> + struct gdbarch *gdbarch = target_gdbarch ();
> +
> + /* Make sure we have a way to decode the memory tag notes. */
> + if (!gdbarch_decode_memtag_section_p (gdbarch))
> + error (_("gdbarch_decode_memtag_section not implemented for this "
> + "architecture."));
> +
> + memtag_section_info info;
> + info.memtag_section = nullptr;
> +
> + while (get_next_core_memtag_section (core_bfd, info.memtag_section,
> + address, info))
> + {
> + size_t adjusted_length
> + = (address + len < info.end_address)? len : (info.end_address - address);
> +
> + /* Decode the memory tag note and return the tags. */
> + gdb::byte_vector tags_read
> + = gdbarch_decode_memtag_section (gdbarch, info.memtag_section, type,
> + address, adjusted_length);
> +
> + /* Transfer over the tags that have been read. */
> + tags.insert (tags.end (), tags_read.begin (), tags_read.end ());
> +
> + /* ADDRESS + LEN may cross the boundaries of a particular memory tag
> + segment. Check if we need to fetch tags from a different section. */
> + if (!tags_read.empty () && (address + len) < info.end_address)
> + return true;
> +
> + /* There are more tags to fetch. Update ADDRESS and LEN. */
> + len -= (info.end_address - address);
> + address = info.end_address;
> + }
> +
> + return false;
> +}
> +
> /* Get a pointer to the current core target. If not connected to a
> core target, return NULL. */
>
> diff --git a/gdb/defs.h b/gdb/defs.h
> index 99bfdd526ff..51a7576a56a 100644
> --- a/gdb/defs.h
> +++ b/gdb/defs.h
> @@ -344,7 +344,8 @@ extern const char *pc_prefix (CORE_ADDR);
>
> typedef int (*find_memory_region_ftype) (CORE_ADDR addr, unsigned long size,
> int read, int write, int exec,
> - int modified, void *data);
> + int modified, bool memory_tagged,
> + void *data);
>
> /* * Possible lvalue types. Like enum language, this should be in
> value.h, but needs to be here for the same reason. */
> diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
> index 38ad2ac32b0..36f10f20cfb 100644
> --- a/gdb/doc/gdb.texinfo
> +++ b/gdb/doc/gdb.texinfo
> @@ -25555,6 +25555,25 @@ options that can be controlled at runtime and emulates the @code{prctl}
> option @code{PR_SET_TAGGED_ADDR_CTRL}. For further information, see the
> documentation in the Linux kernel.
>
> +@value{GDBN} supports dumping memory tag data to core files through the
> +@command{gcore} command and reading memory tag data from core files generated
> +by the @command{gcore} command or the Linux kernel.
> +
> +When a process uses memory-mapped pages protected by memory tags (for
> +example, AArch64 MTE), this additional information will be recorded in
> +the core file in the event of a crash or if @value{GDBN} generates a core file
> +from the current process state.
> +
> +The memory tag data will be used so developers can display the memory
> +tags from a particular memory region (using the @samp{m} modifier to the
> +@command{x} command, using the @command{print} command or using the various
> +@command{memory-tag} subcommands.
> +
> +In the case of a crash, @value{GDBN} will attempt to retrieve the memory tag
> +information automatically from the core file, and will show one of the above
> +messages depending on whether the synchronous or asynchronous mode is selected.
> +@xref{Memory Tagging}. @xref{Memory}.
> +
> @node i386
> @subsection x86 Architecture-specific Issues
>
> diff --git a/gdb/gcore.c b/gdb/gcore.c
> index fdb22b72a07..b81ef81ab84 100644
> --- a/gdb/gcore.c
> +++ b/gdb/gcore.c
> @@ -349,6 +349,12 @@ make_output_phdrs (bfd *obfd, asection *osec)
> int p_flags = 0;
> int p_type = 0;
>
> + /* Memory tag segments have already been handled by the architecture, as
> + those contain arch-specific information. If we have one of those, just
> + return. */
> + if (startswith (bfd_section_name (osec), "memtag"))
> + return;
> +
> /* FIXME: these constants may only be applicable for ELF. */
> if (startswith (bfd_section_name (osec), "load"))
> p_type = PT_LOAD;
> @@ -371,7 +377,8 @@ make_output_phdrs (bfd *obfd, asection *osec)
>
> static int
> gcore_create_callback (CORE_ADDR vaddr, unsigned long size, int read,
> - int write, int exec, int modified, void *data)
> + int write, int exec, int modified, bool memory_tagged,
> + void *data)
> {
> bfd *obfd = (bfd *) data;
> asection *osec;
> @@ -454,6 +461,45 @@ gcore_create_callback (CORE_ADDR vaddr, unsigned long size, int read,
> return 0;
> }
>
> +/* gdbarch_find_memory_region callback for creating a memory tag section.
> + DATA is 'bfd *' for the core file GDB is creating. */
> +
> +static int
> +gcore_create_memtag_section_callback (CORE_ADDR vaddr, unsigned long size,
> + int read, int write, int exec,
> + int modified, bool memory_tagged,
> + void *data)
> +{
> + /* Are there memory tags in this particular memory map entry? */
> + if (!memory_tagged)
> + return 0;
> +
> + bfd *obfd = (bfd *) data;
> +
> + /* Ask the architecture to create a memory tag section for this particular
> + memory map entry. It will be populated with contents later, as we can't
> + start writing the contents before we have all the sections sorted out. */
> + asection *memtag_section
> + = gdbarch_create_memtag_section (target_gdbarch (), obfd, vaddr, size);
> +
> + if (memtag_section == nullptr)
> + {
> + warning (_("Couldn't make gcore memory tag segment: %s"),
> + bfd_errmsg (bfd_get_error ()));
> + return 1;
> + }
> +
> + if (info_verbose)
> + {
> + gdb_printf (gdb_stdout, "Saved memory tag segment, %s bytes "
> + "at %s\n",
> + plongest (bfd_section_size (memtag_section)),
> + paddress (target_gdbarch (), vaddr));
> + }
> +
> + return 0;
> +}
> +
> int
> objfile_find_memory_regions (struct target_ops *self,
> find_memory_region_ftype func, void *obfd)
> @@ -483,6 +529,7 @@ objfile_find_memory_regions (struct target_ops *self,
> (flags & SEC_READONLY) == 0, /* Writable. */
> (flags & SEC_CODE) != 0, /* Executable. */
> 1, /* MODIFIED is unknown, pass it as true. */
> + false, /* No memory tags in the object file. */
> obfd);
> if (ret != 0)
> return ret;
> @@ -496,6 +543,7 @@ objfile_find_memory_regions (struct target_ops *self,
> 1, /* Stack section will be writable. */
> 0, /* Stack section will not be executable. */
> 1, /* Stack section will be modified. */
> + false, /* No memory tags in the object file. */
> obfd);
>
> /* Make a heap segment. */
> @@ -506,6 +554,7 @@ objfile_find_memory_regions (struct target_ops *self,
> 1, /* Heap section will be writable. */
> 0, /* Heap section will not be executable. */
> 1, /* Heap section will be modified. */
> + false, /* No memory tags in the object file. */
> obfd);
>
> return 0;
> @@ -555,6 +604,20 @@ gcore_copy_callback (bfd *obfd, asection *osec)
> }
> }
>
> +/* Callback to copy contents to a particular memory tag section. */
> +
> +static void
> +gcore_copy_memtag_section_callback (bfd *obfd, asection *osec)
> +{
> + /* We are only interested in "memtag" sections. */
> + if (!startswith (bfd_section_name (osec), "memtag"))
> + return;
> +
> + /* Fill the section with memory tag contents. */
> + if (!gdbarch_fill_memtag_section (target_gdbarch (), osec))
> + error (_("Failed to fill memory tag section for core file."));
> +}
> +
> static int
> gcore_memory_sections (bfd *obfd)
> {
> @@ -567,13 +630,27 @@ gcore_memory_sections (bfd *obfd)
> return 0; /* FIXME: error return/msg? */
> }
>
> + /* Take care of dumping memory tags, if there are any. */
> + if (!gdbarch_find_memory_regions_p (target_gdbarch ())
> + || gdbarch_find_memory_regions (target_gdbarch (),
> + gcore_create_memtag_section_callback,
> + obfd) != 0)
> + {
> + if (target_find_memory_regions (gcore_create_memtag_section_callback,
> + obfd) != 0)
> + return 0;
> + }
> +
> /* Record phdrs for section-to-segment mapping. */
> for (asection *sect : gdb_bfd_sections (obfd))
> make_output_phdrs (obfd, sect);
>
> - /* Copy memory region contents. */
> + /* Copy memory region and memory tag contents. */
> for (asection *sect : gdb_bfd_sections (obfd))
> - gcore_copy_callback (obfd, sect);
> + {
> + gcore_copy_callback (obfd, sect);
> + gcore_copy_memtag_section_callback (obfd, sect);
> + }
>
> return 1;
> }
> diff --git a/gdb/gdbarch-components.py b/gdb/gdbarch-components.py
> index e8f20c83ff0..6fa1b7591db 100644
> --- a/gdb/gdbarch-components.py
> +++ b/gdb/gdbarch-components.py
> @@ -1522,6 +1522,41 @@ Find core file memory regions
> invalid=True,
> )
>
> +Method(
> + comment="""
> +Given a bfd OBFD, segment ADDRESS and SIZE, create a memory tag section to be dumped to a core file
> +""",
> + type="asection *",
> + name="create_memtag_section",
> + params=[("bfd *", "obfd"), ("CORE_ADDR", "address"), ("size_t", "size")],
> + predicate=True,
> + invalid=True,
> +)
> +
> +Method(
> + comment="""
> +Given a memory tag section OSEC, fill OSEC's contents with the appropriate tag data
> +""",
> + type="bool",
> + name="fill_memtag_section",
> + params=[("asection *", "osec")],
> + predicate=True,
> + invalid=True,
> +)
> +
> +Method(
> + comment="""
> +Decode a memory tag SECTION and return the tags of type TYPE contained in
> +the memory range [ADDRESS, ADDRESS + LENGTH).
> +If no tags were found, return an empty vector.
> +""",
> + type="gdb::byte_vector",
> + name="decode_memtag_section",
> + params=[("bfd_section *", "section"), ("int", "type"), ("CORE_ADDR", "address"), ("size_t", "length")],
> + predicate=True,
> + invalid=True,
> +)
> +
> Method(
> comment="""
> Read offset OFFSET of TARGET_OBJECT_LIBRARIES formatted shared libraries list from
> diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h
> index 882b9057b1a..1d19f51f21d 100644
> --- a/gdb/gdbarch-gen.h
> +++ b/gdb/gdbarch-gen.h
> @@ -874,6 +874,32 @@ typedef int (gdbarch_find_memory_regions_ftype) (struct gdbarch *gdbarch, find_m
> extern int gdbarch_find_memory_regions (struct gdbarch *gdbarch, find_memory_region_ftype func, void *data);
> extern void set_gdbarch_find_memory_regions (struct gdbarch *gdbarch, gdbarch_find_memory_regions_ftype *find_memory_regions);
>
> +/* Given a bfd OBFD, segment ADDRESS and SIZE, create a memory tag section to be dumped to a core file */
> +
> +extern bool gdbarch_create_memtag_section_p (struct gdbarch *gdbarch);
> +
> +typedef asection * (gdbarch_create_memtag_section_ftype) (struct gdbarch *gdbarch, bfd *obfd, CORE_ADDR address, size_t size);
> +extern asection * gdbarch_create_memtag_section (struct gdbarch *gdbarch, bfd *obfd, CORE_ADDR address, size_t size);
> +extern void set_gdbarch_create_memtag_section (struct gdbarch *gdbarch, gdbarch_create_memtag_section_ftype *create_memtag_section);
> +
> +/* Given a memory tag section OSEC, fill OSEC's contents with the appropriate tag data */
> +
> +extern bool gdbarch_fill_memtag_section_p (struct gdbarch *gdbarch);
> +
> +typedef bool (gdbarch_fill_memtag_section_ftype) (struct gdbarch *gdbarch, asection *osec);
> +extern bool gdbarch_fill_memtag_section (struct gdbarch *gdbarch, asection *osec);
> +extern void set_gdbarch_fill_memtag_section (struct gdbarch *gdbarch, gdbarch_fill_memtag_section_ftype *fill_memtag_section);
> +
> +/* Decode a memory tag SECTION and return the tags of type TYPE contained in
> + the memory range [ADDRESS, ADDRESS + LENGTH).
> + If no tags were found, return an empty vector. */
> +
> +extern bool gdbarch_decode_memtag_section_p (struct gdbarch *gdbarch);
> +
> +typedef gdb::byte_vector (gdbarch_decode_memtag_section_ftype) (struct gdbarch *gdbarch, bfd_section *section, int type, CORE_ADDR address, size_t length);
> +extern gdb::byte_vector gdbarch_decode_memtag_section (struct gdbarch *gdbarch, bfd_section *section, int type, CORE_ADDR address, size_t length);
> +extern void set_gdbarch_decode_memtag_section (struct gdbarch *gdbarch, gdbarch_decode_memtag_section_ftype *decode_memtag_section);
> +
> /* Read offset OFFSET of TARGET_OBJECT_LIBRARIES formatted shared libraries list from
> core file into buffer READBUF with length LEN. Return the number of bytes read
> (zero indicates failure).
> diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
> index a588bdef61a..f5dbacb14e7 100644
> --- a/gdb/gdbarch.c
> +++ b/gdb/gdbarch.c
> @@ -171,6 +171,9 @@ struct gdbarch
> gdbarch_iterate_over_regset_sections_ftype *iterate_over_regset_sections;
> gdbarch_make_corefile_notes_ftype *make_corefile_notes;
> gdbarch_find_memory_regions_ftype *find_memory_regions;
> + gdbarch_create_memtag_section_ftype *create_memtag_section;
> + gdbarch_fill_memtag_section_ftype *fill_memtag_section;
> + gdbarch_decode_memtag_section_ftype *decode_memtag_section;
> gdbarch_core_xfer_shared_libraries_ftype *core_xfer_shared_libraries;
> gdbarch_core_xfer_shared_libraries_aix_ftype *core_xfer_shared_libraries_aix;
> gdbarch_core_pid_to_str_ftype *core_pid_to_str;
> @@ -527,6 +530,9 @@ verify_gdbarch (struct gdbarch *gdbarch)
> /* Skip verify of iterate_over_regset_sections, has predicate. */
> /* Skip verify of make_corefile_notes, has predicate. */
> /* Skip verify of find_memory_regions, has predicate. */
> + /* Skip verify of create_memtag_section, has predicate. */
> + /* Skip verify of fill_memtag_section, has predicate. */
> + /* Skip verify of decode_memtag_section, has predicate. */
> /* Skip verify of core_xfer_shared_libraries, has predicate. */
> /* Skip verify of core_xfer_shared_libraries_aix, has predicate. */
> /* Skip verify of core_pid_to_str, has predicate. */
> @@ -1096,6 +1102,24 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
> gdb_printf (file,
> "gdbarch_dump: find_memory_regions = <%s>\n",
> host_address_to_string (gdbarch->find_memory_regions));
> + gdb_printf (file,
> + "gdbarch_dump: gdbarch_create_memtag_section_p() = %d\n",
> + gdbarch_create_memtag_section_p (gdbarch));
> + gdb_printf (file,
> + "gdbarch_dump: create_memtag_section = <%s>\n",
> + host_address_to_string (gdbarch->create_memtag_section));
> + gdb_printf (file,
> + "gdbarch_dump: gdbarch_fill_memtag_section_p() = %d\n",
> + gdbarch_fill_memtag_section_p (gdbarch));
> + gdb_printf (file,
> + "gdbarch_dump: fill_memtag_section = <%s>\n",
> + host_address_to_string (gdbarch->fill_memtag_section));
> + gdb_printf (file,
> + "gdbarch_dump: gdbarch_decode_memtag_section_p() = %d\n",
> + gdbarch_decode_memtag_section_p (gdbarch));
> + gdb_printf (file,
> + "gdbarch_dump: decode_memtag_section = <%s>\n",
> + host_address_to_string (gdbarch->decode_memtag_section));
> gdb_printf (file,
> "gdbarch_dump: gdbarch_core_xfer_shared_libraries_p() = %d\n",
> gdbarch_core_xfer_shared_libraries_p (gdbarch));
> @@ -3744,6 +3768,78 @@ set_gdbarch_find_memory_regions (struct gdbarch *gdbarch,
> gdbarch->find_memory_regions = find_memory_regions;
> }
>
> +bool
> +gdbarch_create_memtag_section_p (struct gdbarch *gdbarch)
> +{
> + gdb_assert (gdbarch != NULL);
> + return gdbarch->create_memtag_section != NULL;
> +}
> +
> +asection *
> +gdbarch_create_memtag_section (struct gdbarch *gdbarch, bfd *obfd, CORE_ADDR address, size_t size)
> +{
> + gdb_assert (gdbarch != NULL);
> + gdb_assert (gdbarch->create_memtag_section != NULL);
> + if (gdbarch_debug >= 2)
> + gdb_printf (gdb_stdlog, "gdbarch_create_memtag_section called\n");
> + return gdbarch->create_memtag_section (gdbarch, obfd, address, size);
> +}
> +
> +void
> +set_gdbarch_create_memtag_section (struct gdbarch *gdbarch,
> + gdbarch_create_memtag_section_ftype create_memtag_section)
> +{
> + gdbarch->create_memtag_section = create_memtag_section;
> +}
> +
> +bool
> +gdbarch_fill_memtag_section_p (struct gdbarch *gdbarch)
> +{
> + gdb_assert (gdbarch != NULL);
> + return gdbarch->fill_memtag_section != NULL;
> +}
> +
> +bool
> +gdbarch_fill_memtag_section (struct gdbarch *gdbarch, asection *osec)
> +{
> + gdb_assert (gdbarch != NULL);
> + gdb_assert (gdbarch->fill_memtag_section != NULL);
> + if (gdbarch_debug >= 2)
> + gdb_printf (gdb_stdlog, "gdbarch_fill_memtag_section called\n");
> + return gdbarch->fill_memtag_section (gdbarch, osec);
> +}
> +
> +void
> +set_gdbarch_fill_memtag_section (struct gdbarch *gdbarch,
> + gdbarch_fill_memtag_section_ftype fill_memtag_section)
> +{
> + gdbarch->fill_memtag_section = fill_memtag_section;
> +}
> +
> +bool
> +gdbarch_decode_memtag_section_p (struct gdbarch *gdbarch)
> +{
> + gdb_assert (gdbarch != NULL);
> + return gdbarch->decode_memtag_section != NULL;
> +}
> +
> +gdb::byte_vector
> +gdbarch_decode_memtag_section (struct gdbarch *gdbarch, bfd_section *section, int type, CORE_ADDR address, size_t length)
> +{
> + gdb_assert (gdbarch != NULL);
> + gdb_assert (gdbarch->decode_memtag_section != NULL);
> + if (gdbarch_debug >= 2)
> + gdb_printf (gdb_stdlog, "gdbarch_decode_memtag_section called\n");
> + return gdbarch->decode_memtag_section (gdbarch, section, type, address, length);
> +}
> +
> +void
> +set_gdbarch_decode_memtag_section (struct gdbarch *gdbarch,
> + gdbarch_decode_memtag_section_ftype decode_memtag_section)
> +{
> + gdbarch->decode_memtag_section = decode_memtag_section;
> +}
> +
> bool
> gdbarch_core_xfer_shared_libraries_p (struct gdbarch *gdbarch)
> {
> diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
> index 4e728a06e7e..8a83ed320cf 100644
> --- a/gdb/linux-tdep.c
> +++ b/gdb/linux-tdep.c
> @@ -42,6 +42,7 @@
> #include "gcore.h"
> #include "gcore-elf.h"
> #include "solib-svr4.h"
> +#include "memtag.h"
>
> #include <ctype.h>
> #include <unordered_map>
> @@ -1320,6 +1321,7 @@ typedef int linux_find_memory_region_ftype (ULONGEST vaddr, ULONGEST size,
> ULONGEST offset, ULONGEST inode,
> int read, int write,
> int exec, int modified,
> + bool memory_tagged,
> const char *filename,
> void *data);
>
> @@ -1470,10 +1472,11 @@ parse_smaps_data (const char *data,
> return smaps;
> }
>
> -/* See linux-tdep.h. */
> +/* Helper that checks if an address is in a memory tag page for a live
> + process. */
>
> -bool
> -linux_address_in_memtag_page (CORE_ADDR address)
> +static bool
> +linux_process_address_in_memtag_page (CORE_ADDR address)
> {
> if (current_inferior ()->fake_pid_p)
> return false;
> @@ -1505,6 +1508,30 @@ linux_address_in_memtag_page (CORE_ADDR address)
> return false;
> }
>
> +/* Helper that checks if an address is in a memory tag page for a core file
> + process. */
> +
> +static bool
> +linux_core_file_address_in_memtag_page (CORE_ADDR address)
> +{
> + if (core_bfd == nullptr)
> + return false;
> +
> + memtag_section_info info;
> + return get_next_core_memtag_section (core_bfd, nullptr, address, info);
> +}
> +
> +/* See linux-tdep.h. */
> +
> +bool
> +linux_address_in_memtag_page (CORE_ADDR address)
> +{
> + if (!target_has_execution ())
> + return linux_core_file_address_in_memtag_page (address);
> +
> + return linux_process_address_in_memtag_page (address);
> +}
> +
> /* List memory regions in the inferior for a corefile. */
>
> static int
> @@ -1593,6 +1620,7 @@ linux_find_memory_regions_full (struct gdbarch *gdbarch,
> map.offset, map.inode, map.read, map.write, map.exec,
> 1, /* MODIFIED is true because we want to dump
> the mapping. */
> + map.vmflags.memory_tagging != 0,
> map.filename.c_str (), obfd);
> }
> }
> @@ -1621,12 +1649,14 @@ static int
> linux_find_memory_regions_thunk (ULONGEST vaddr, ULONGEST size,
> ULONGEST offset, ULONGEST inode,
> int read, int write, int exec, int modified,
> + bool memory_tagged,
> const char *filename, void *arg)
> {
> struct linux_find_memory_regions_data *data
> = (struct linux_find_memory_regions_data *) arg;
>
> - return data->func (vaddr, size, read, write, exec, modified, data->obfd);
> + return data->func (vaddr, size, read, write, exec, modified, memory_tagged,
> + data->obfd);
> }
>
> /* A variant of linux_find_memory_regions_full that is suitable as the
> @@ -1675,6 +1705,7 @@ static int
> linux_make_mappings_callback (ULONGEST vaddr, ULONGEST size,
> ULONGEST offset, ULONGEST inode,
> int read, int write, int exec, int modified,
> + bool memory_tagged,
> const char *filename, void *data)
> {
> struct linux_make_mappings_data *map_data
> diff --git a/gdb/memtag.c b/gdb/memtag.c
> new file mode 100644
> index 00000000000..af86137c49d
> --- /dev/null
> +++ b/gdb/memtag.c
> @@ -0,0 +1,61 @@
> +/* GDB generic memory tagging functions.
> +
> + Copyright (C) 2022 Free Software Foundation, Inc.
> +
> + This file is part of GDB.
> +
> + This program is free software; you can redistribute it and/or modify
> + it under the terms of the GNU General Public License as published by
> + the Free Software Foundation; either version 3 of the License, or
> + (at your option) any later version.
> +
> + This program is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + GNU General Public License for more details.
> +
> + You should have received a copy of the GNU General Public License
> + along with this program. If not, see <http://www.gnu.org/licenses/>. */
> +
> +#include "defs.h"
> +#include "memtag.h"
> +#include "bfd.h"
> +
> +/* See memtag.h */
> +
> +bool
> +get_next_core_memtag_section (bfd *abfd, asection *section,
> + CORE_ADDR address, memtag_section_info &info)
> +{
> + /* If the caller provided no SECTION to start from, search from the
> + beginning. */
> + if (section == nullptr)
> + section = bfd_get_section_by_name (abfd, "memtag");
> +
> + /* Go through all the memtag sections and figure out if ADDRESS
> + falls within one of the memory ranges that contain tags. */
> + while (section != nullptr)
> + {
> + size_t memtag_range_size = section->rawsize;
> + size_t tags_size = bfd_section_size (section);
> +
> + /* Empty memory range and empty tag dump should not happen. */
> + gdb_assert (memtag_range_size != 0);
> + gdb_assert (tags_size != 0);
> +
> + CORE_ADDR start_address = bfd_section_vma (section);
> + CORE_ADDR end_address = start_address + memtag_range_size;
> +
> + /* Is the address within [start_address, end_address)? */
> + if (address >= start_address
> + && address < end_address)
> + {
> + info.start_address = start_address;
> + info.end_address = end_address;
> + info.memtag_section = section;
> + return true;
> + }
> + section = bfd_get_next_section_by_name (abfd, section);
> + }
> + return false;
> +}
> diff --git a/gdb/memtag.h b/gdb/memtag.h
> new file mode 100644
> index 00000000000..fe908c1e5e3
> --- /dev/null
> +++ b/gdb/memtag.h
> @@ -0,0 +1,50 @@
> +/* GDB generic memory tagging definitions.
> + Copyright (C) 2022 Free Software Foundation, Inc.
> +
> + This file is part of GDB.
> +
> + This program is free software; you can redistribute it and/or modify
> + it under the terms of the GNU General Public License as published by
> + the Free Software Foundation; either version 3 of the License, or
> + (at your option) any later version.
> +
> + This program is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + GNU General Public License for more details.
> +
> + You should have received a copy of the GNU General Public License
> + along with this program. If not, see <http://www.gnu.org/licenses/>. */
> +
> +#ifndef MEMTAG_H
> +#define MEMTAG_H
> +
> +#include "bfd.h"
> +
> +struct memtag_section_info
> +{
> + /* The start address of the tagged memory range. */
> + CORE_ADDR start_address;
> + /* The final address of the tagged memory range. */
> + CORE_ADDR end_address;
> + /* The section containing tags for the memory range
> + [start_address, end_address). */
> + asection *memtag_section;
> +};
> +
> +/* Helper function to walk through memory tag sections in a core file.
> +
> + Return TRUE if there is a "memtag" section containing ADDRESS. Return FALSE
> + otherwise.
> +
> + If SECTION is provided, search from that section onwards. If SECTION is
> + nullptr, then start a new search.
> +
> + If a "memtag" section containing ADDRESS is found, fill INFO with data
> + about such section. Otherwise leave it unchanged. */
> +
> +bool get_next_core_memtag_section (bfd *abfd, asection *section,
> + CORE_ADDR address,
> + memtag_section_info &info);
> +
> +#endif /* MEMTAG_H */
> diff --git a/gdb/testsuite/gdb.arch/aarch64-mte-gcore.c b/gdb/testsuite/gdb.arch/aarch64-mte-gcore.c
> new file mode 100644
> index 00000000000..b20ebcff424
> --- /dev/null
> +++ b/gdb/testsuite/gdb.arch/aarch64-mte-gcore.c
> @@ -0,0 +1,93 @@
> +/* This test program is part of GDB, the GNU debugger.
> +
> + Copyright 2021 Free Software Foundation, Inc.
> +
> + This program is free software; you can redistribute it and/or modify
> + it under the terms of the GNU General Public License as published by
> + the Free Software Foundation; either version 3 of the License, or
> + (at your option) any later version.
> +
> + This program is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + GNU General Public License for more details.
> +
> + You should have received a copy of the GNU General Public License
> + along with this program. If not, see <http://www.gnu.org/licenses/>. */
> +
> +/* Exercise AArch64's Memory Tagging Extension with tagged pointers. */
> +
> +/* This test was based on the documentation for the AArch64 Memory Tagging
> + Extension from the Linux Kernel, found in the sources in
> + Documentation/arm64/memory-tagging-extension.rst. */
> +
> +#include <errno.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <unistd.h>
> +#include <sys/auxv.h>
> +#include <sys/mman.h>
> +#include <sys/prctl.h>
> +
> +/* From arch/arm64/include/uapi/asm/hwcap.h */
> +#define HWCAP2_MTE (1 << 18)
> +
> +/* From arch/arm64/include/uapi/asm/mman.h */
> +#define PROT_MTE 0x20
> +
> +/* From include/uapi/linux/prctl.h */
> +#define PR_SET_TAGGED_ADDR_CTRL 55
> +#define PR_GET_TAGGED_ADDR_CTRL 56
> +#define PR_TAGGED_ADDR_ENABLE (1UL << 0)
> +#define PR_MTE_TCF_SHIFT 1
> +#define PR_MTE_TCF_SYNC (1UL << PR_MTE_TCF_SHIFT)
> +#define PR_MTE_TAG_SHIFT 3
> +
> +void
> +access_memory (unsigned char *tagged_ptr)
> +{
> + tagged_ptr[0] = 'a';
> +}
> +
> +int
> +main (int argc, char **argv)
> +{
> + unsigned char *tagged_ptr;
> + unsigned long page_sz = sysconf (_SC_PAGESIZE);
> + unsigned long hwcap2 = getauxval(AT_HWCAP2);
> +
> + /* Bail out if MTE is not supported. */
> + if (!(hwcap2 & HWCAP2_MTE))
> + return 1;
> +
> + /* Enable the tagged address ABI, synchronous MTE tag check faults and
> + allow all non-zero tags in the randomly generated set. */
> + if (prctl (PR_SET_TAGGED_ADDR_CTRL,
> + PR_TAGGED_ADDR_ENABLE | PR_MTE_TCF_SYNC
> + | (0xfffe << PR_MTE_TAG_SHIFT),
> + 0, 0, 0))
> + {
> + perror ("prctl () failed");
> + return 1;
> + }
> +
> + /* Create a mapping that will have PROT_MTE set. */
> + tagged_ptr = mmap (0, page_sz, PROT_READ | PROT_WRITE,
> + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
> + if (tagged_ptr == MAP_FAILED)
> + {
> + perror ("mmap () failed");
> + return 1;
> + }
> +
> + /* Enable MTE on the above anonymous mmap. */
> + if (mprotect (tagged_ptr, page_sz, PROT_READ | PROT_WRITE | PROT_MTE))
> + {
> + perror ("mprotect () failed");
> + return 1;
> + }
> +
> + access_memory (tagged_ptr);
> +
> + return 0;
> +}
> diff --git a/gdb/testsuite/gdb.arch/aarch64-mte-gcore.exp b/gdb/testsuite/gdb.arch/aarch64-mte-gcore.exp
> new file mode 100644
> index 00000000000..8a19c4b449e
> --- /dev/null
> +++ b/gdb/testsuite/gdb.arch/aarch64-mte-gcore.exp
> @@ -0,0 +1,107 @@
> +# Copyright (C) 2018-2021 Free Software Foundation, Inc.
> +#
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program. If not, see <http://www.gnu.org/licenses/>.
> +
> +# This file is part of the gdb testsuite.
> +
> +# Test generating and reading a core file with MTE memory tags.
> +
> +if {![is_aarch64_target]} {
> + verbose "Skipping ${gdb_test_file_name}."
> + return
> +}
> +
> +standard_testfile
> +if { [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] } {
> + return -1
> +}
> +
> +if ![runto_main] {
> + untested "could not run to main"
> + return -1
> +}
> +
> +# Targets that don't support memory tagging should not execute the
> +# runtime memory tagging tests.
> +if {![supports_memtag]} {
> + unsupported "memory tagging unsupported"
> + return -1
> +}
> +
> +gdb_breakpoint "access_memory"
> +
> +if [gdb_continue "access_memory"] {
> + return -1
> +}
> +
> +# Set each tag granule to a different tag value, from 0x0 to 0xf.
> +set atag_msg "Allocation tag\\(s\\) updated successfully\."
> +for {set i 15} {$i >= 0} {incr i -1} {
> + set index [expr [expr 15 - $i] * 16]
> + set tag [format "%02x" $i]
> + gdb_test "memory-tag set-allocation-tag &tagged_ptr\[$index\] 1 $tag" \
> + $atag_msg \
> + "set memory tag of &tagged_ptr\[$index\] to $tag"
> +}
> +
> +# Run until a crash and confirm GDB displays memory tag violation
> +# information.
> +gdb_test "continue" \
> + [multi_line \
> + "Program received signal SIGSEGV, Segmentation fault" \
> + "Memory tag violation while accessing address $hex" \
> + "Allocation tag $hex" \
> + "Logical tag $hex\." \
> + "$hex in access_memory \\(.*\\) at .*" \
> + ".*tagged_ptr\\\[0\\\] = 'a';"] \
> + "display tag violation information for live process"
> +
> +# Generate the core file.
> +set core_filename [standard_output_file "$testfile.core"]
> +set core_generated [gdb_gcore_cmd "$core_filename" "generate core file"]
> +
> +if { !$core_generated } {
> + return -1
> +}
> +
> +clean_restart $binfile
> +
> +# Load the core file and make sure we see the tag violation fault
> +# information.
> +gdb_test "core $core_filename" \
> + [multi_line \
> + "Core was generated by.*\." \
> + "Program terminated with signal SIGSEGV, Segmentation fault" \
> + "Memory tag violation while accessing address $hex" \
> + "Allocation tag 0xf" \
> + "Logical tag 0x0\." \
> + "#0.*$hex in access_memory \\(.*\\) at .*" \
> + ".*tagged_ptr\\\[0\\\] = 'a';"] \
> + "core file shows tag violation information"
> +
> +# Make sure we have the tag_ctl register.
> +gdb_test "info register tag_ctl" \
> + "tag_ctl.*$hex.*${::decimal}" \
> + "tag_ctl is available"
> +
> +# Check if the tag granules have the expected values. If they do, that
> +# means the core file saved the tags properly and GDB has read them
> +# correctly.
> +for {set i 15} {$i >= 0} {incr i -1} {
> + set index [expr [expr 15 - $i] * 16]
> + set tag [format "%x" $i]
> + gdb_test "memory-tag print-allocation-tag &tagged_ptr\[$index\]" \
> + "= 0x$tag" \
> + "memory tag of &tagged_ptr\[$index\] is correct"
> +}
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