memattr.c \
memory-map.c \
memrange.c \
+ memtag.c \
minidebug.c \
minsyms.c \
mipsread.c \
*** 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.
+
* "info breakpoints" now displays enabled breakpoint locations of
disabled breakpoints as in the "y-" state. For example:
#include "gdbsupport/selftest.h"
+#include "elf/common.h"
+#include "elf/aarch64.h"
+
/* Signal frame handling.
+------------+ ^
}
}
+/* 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.
+
+ Make sure the section's flags has SEC_HAS_CONTENTS, otherwise BFD will
+ refuse to write data to this section. */
+ asection *mte_section
+ = bfd_make_section_anyway_with_flags (obfd, "memtag", SEC_HAS_CONTENTS);
+
+ 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;
+
+ /* Fetch the number of tags we need to save. */
+ size_t tags_count
+ = aarch64_mte_get_tag_granules (address, size, AARCH64_MTE_GRANULE_SIZE);
+ /* Tags are stored packed as 2 tags per byte. */
+ bfd_set_section_size (mte_section, (tags_count + 1) >> 1);
+ /* 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)
{
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. */
/* 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)
{
/* 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
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. */
+extern 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. */
+extern void aarch64_mte_unpack_tags (gdb::byte_vector &tags, bool skip_first);
+
#endif /* ARCH_AARCH64_MTE_LINUX_H */
#include <unordered_set>
#include "gdbcmd.h"
#include "xml-tdesc.h"
+#include "memtag.h"
#ifndef O_LARGEFILE
#define O_LARGEFILE 0
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. */
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. */
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. */
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
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;
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;
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)
(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;
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. */
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;
}
}
+/* 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)
{
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;
}
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
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).
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;
/* 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. */
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));
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)
{
#include "gcore.h"
#include "gcore-elf.h"
#include "solib-svr4.h"
+#include "memtag.h"
#include <ctype.h>
#include <unordered_map>
ULONGEST offset, ULONGEST inode,
int read, int write,
int exec, int modified,
+ bool memory_tagged,
const char *filename,
void *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;
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
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);
}
}
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
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
--- /dev/null
+/* 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 or empty tag dump should not happen. Warn about
+ it but keep going through the sections. */
+ if (memtag_range_size == 0 || tags_size == 0)
+ {
+ warning (_("Found memtag section with empty memory "
+ "range or empty tag dump"));
+ continue;
+ }
+ else
+ {
+ 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;
+}
--- /dev/null
+/* 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 */
--- /dev/null
+/* This test program is part of GDB, the GNU debugger.
+
+ Copyright 2022 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 corefile support. We allocate
+ multiple memory mappings with PROT_MTE and assign tag values for all the
+ existing MTE granules. */
+
+/* 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 */
+#ifndef HWCAP2_MTE
+#define HWCAP2_MTE (1 << 18)
+#endif
+
+/* From arch/arm64/include/uapi/asm/mman.h */
+#ifndef PROT_MTE
+#define PROT_MTE 0x20
+#endif
+
+#ifndef PR_SET_TAGGED_ADDR_CTRL
+#define PR_SET_TAGGED_ADDR_CTRL 55
+#define PR_TAGGED_ADDR_ENABLE (1UL << 0)
+#endif
+
+/* From include/uapi/linux/prctl.h */
+#ifndef PR_MTE_TCF_SHIFT
+#define PR_MTE_TCF_SHIFT 1
+#define PR_MTE_TCF_SYNC (1UL << PR_MTE_TCF_SHIFT)
+#define PR_MTE_TCF_ASYNC (2UL << PR_MTE_TCF_SHIFT)
+#define PR_MTE_TAG_SHIFT 3
+#define PR_MTE_TAG_MASK (0xffffUL << PR_MTE_TAG_SHIFT)
+#endif
+
+#ifdef ASYNC
+#define TCF_MODE PR_MTE_TCF_ASYNC
+#else
+#define TCF_MODE PR_MTE_TCF_SYNC
+#endif
+
+#define NMAPS 5
+
+/* We store the pointers and sizes of the memory maps we requested. Each
+ of them has a different size. */
+unsigned char *mmap_pointers[NMAPS];
+
+/* Set the allocation tag on the destination address. */
+#define set_tag(tagged_addr) do { \
+ asm volatile("stg %0, [%0]" : : "r" (tagged_addr) : "memory"); \
+} while (0)
+
+
+uintptr_t
+set_logical_tag (uintptr_t ptr, unsigned char tag)
+{
+ ptr &= ~0xFF00000000000000ULL;
+ ptr |= ((uintptr_t) tag << 56);
+ return ptr;
+}
+
+void
+fill_map_with_tags (unsigned char *ptr, size_t size, unsigned char *tag)
+{
+ for (size_t start = 0; start < size; start += 16)
+ {
+ set_tag (set_logical_tag (((uintptr_t)ptr + start) & ~(0xFULL), *tag));
+ *tag = (*tag + 1) % 16;
+ }
+}
+
+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 | TCF_MODE
+ | (0xfffe << PR_MTE_TAG_SHIFT),
+ 0, 0, 0))
+ {
+ perror ("prctl () failed");
+ return 1;
+ }
+
+ /* Map a big area of NMAPS * 2 pages. */
+ unsigned char *big_map = mmap (0, NMAPS * 2 * page_sz, PROT_NONE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+ if (big_map == MAP_FAILED)
+ {
+ perror ("mmap () failed");
+ return 1;
+ }
+
+ /* Start with a tag of 0x1 so we can crash later. */
+ unsigned char tag = 1;
+
+ /* From that big area of NMAPS * 2 pages, go through each page and protect
+ alternating pages. This should prevent the kernel from merging different
+ mmap's and force the creation of multiple individual MTE-protected entries
+ in /proc/<pid>/smaps. */
+ for (int i = 0; i < NMAPS; i++)
+ {
+ mmap_pointers[i] = big_map + (i * 2 * page_sz);
+
+ /* Enable MTE on alternating pages. */
+ if (mprotect (mmap_pointers[i], page_sz,
+ PROT_READ | PROT_WRITE | PROT_MTE))
+ {
+ perror ("mprotect () failed");
+ return 1;
+ }
+
+ fill_map_with_tags (mmap_pointers[i], page_sz, &tag);
+ }
+
+ /* The following line causes a crash on purpose. */
+ *mmap_pointers[0] = 0x4;
+
+ return 0;
+}
--- /dev/null
+# Copyright (C) 2018-2022 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.
+
+proc test_mte_core_file { core_filename mode } {
+ # Load the core file and make sure we see the tag violation fault
+ # information.
+ if {$mode == "sync"} {
+ 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 ${::hex}" \
+ "Logical tag ${::hex}\." \
+ "#0.*${::hex} in main \\(.*\\) at .*" \
+ ".*mmap_pointers\\\[0\\\] = 0x4;"] \
+ "core file shows $mode memory tag violation"
+ } else {
+ gdb_test "core $core_filename" \
+ [multi_line \
+ "Core was generated by.*\." \
+ "Program terminated with signal SIGSEGV, Segmentation fault" \
+ "Memory tag violation" \
+ "Fault address unavailable\." \
+ "#0 ${::hex} in .* from .*"] \
+ "core file shows $mode memory tag violation"
+ }
+
+ # Make sure we have the tag_ctl register.
+ gdb_test "info register tag_ctl" \
+ "tag_ctl.*${::hex}.*${::decimal}" \
+ "tag_ctl is available"
+
+ # In ASYNC mode, there is nothing left to test, as the program stops at
+ # a place where further source code inspection is not possible.
+ if {$mode == "async"} {
+ return
+ }
+
+ # First, figure out the page size.
+ set page_size [get_valueof "" "page_sz" "0" \
+ "fetch value of page size"]
+
+ # Get the number of maps for the test
+ set nmaps [get_valueof "" "NMAPS" "0" \
+ "fetch number of maps"]
+ set tag 1
+
+ # Iterate over all of the MTE-protected memory mappings and make sure
+ # GDB retrieves the correct allocation tags for each one. If the tag
+ # has the expected value, that means the core file was generated correctly
+ # and that GDB read the contents correctly.
+ for {set i 0} {$i < $nmaps} {incr i} {
+ for {set offset 0} {$offset < $page_size} {set offset [expr $offset + 16]} {
+ set hex_tag [format "%x" $tag]
+ gdb_test "memory-tag print-allocation-tag mmap_pointers\[$i\] + $offset" \
+ "= 0x$hex_tag" \
+ "mmap_ponters\[$i\] + $offset contains expected tag"
+ # Update the expected tag. The test writes tags in sequential
+ # order.
+ set tag [expr ($tag + 1) % 16]
+ }
+ }
+}
+
+# Exercise MTE corefile support using mode MODE (Async or Sync)
+
+proc test_mode { mode } {
+
+ set compile_flags {"debug" "macros" "additional_flags=-march=armv8.5-a+memtag"}
+
+ # If we are testing async mode, we need to force the testcase to use
+ # such mode.
+ if {$mode == "async"} {
+ lappend compile_flags "additional_flags=-DASYNC"
+ }
+
+ standard_testfile
+ set executable "${::testfile}-${mode}"
+ if {[prepare_for_testing "failed to prepare" ${executable} ${::srcfile} ${compile_flags}]} {
+ return -1
+ }
+ set binfile [standard_output_file ${executable}]
+
+ if ![runto_main] {
+ untested "could not run to main"
+ return -1
+ }
+
+ # Targets that don't support memory tagging should not execute the
+ # runtime memory tagging tests.
+ if {![supports_memtag]} {
+ unsupported "memory tagging unsupported"
+ return -1
+ }
+
+ # Run until a crash and confirm GDB displays memory tag violation
+ # information.
+ if {$mode == "sync"} {
+ gdb_test "continue" \
+ [multi_line \
+ "Program received signal SIGSEGV, Segmentation fault" \
+ "Memory tag violation while accessing address ${::hex}" \
+ "Allocation tag 0x1" \
+ "Logical tag 0x0\." \
+ "${::hex} in main \\(.*\\) at .*" \
+ ".*mmap_pointers\\\[0\\\] = 0x4;"] \
+ "run to memory $mode tag violation"
+ } else {
+ gdb_test "continue" \
+ [multi_line \
+ "Program received signal SIGSEGV, Segmentation fault" \
+ "Memory tag violation" \
+ "Fault address unavailable\." \
+ "${::hex} in .* from .*"] \
+ "run to memory $mode tag violation"
+ }
+
+ # Generate the gcore core file.
+ set gcore_filename [standard_output_file "${executable}.gcore"]
+ set gcore_generated [gdb_gcore_cmd "$gcore_filename" "generate gcore file"]
+
+ # Generate a native core file.
+ set core_filename [core_find ${binfile}]
+ set core_generated [expr {$core_filename != ""}]
+
+ # At this point we have a couple core files, the gcore one generated by GDB
+ # and the native one generated by the Linux Kernel. Make sure GDB can read
+ # both correctly.
+
+ if {$gcore_generated} {
+ clean_restart ${binfile}
+ with_test_prefix "gcore corefile" {
+ test_mte_core_file $gcore_filename $mode
+ }
+ } else {
+ fail "gcore corefile not generated"
+ }
+
+ if {$core_generated} {
+ clean_restart ${binfile}
+ with_test_prefix "native corefile" {
+ test_mte_core_file $core_filename $mode
+ }
+ } else {
+ untested "native corefile not generated"
+ }
+
+}
+
+if {![is_aarch64_target]} {
+ verbose "Skipping ${gdb_test_file_name}."
+ return
+}
+
+# Run tests
+foreach_with_prefix mode {"sync" "async"} {
+ test_mode $mode
+}
projects / binutils-gdb.git / commitdiff