This makes it possible to use LIBCTF_DEBUG to debug things that happen
before the ctf_bfdopen_internal call that ctf_bfdopen_ctfsect eventually
thunks down to (symtab/strtab lookup, archive opening, etc).
This is not important for ctf_open callers, since ctf_fdopen already
calls libctf_init_debug, but ctf_bfdopen_ctfsect is a public entry point
that can be called directly (e.g. objdump and readelf both do so).
libctf/ChangeLog
2021-03-25 Nick Alcock <nick.alcock@oracle.com>
* ctf-open-bfd.c (ctf_bfdopen_ctfsect): Initialize debugging.
Every place that accesses a function's dtd_vlen accesses it only if the
number of args is nonzero, except the serializer, which always tries to
memcpy it. The number of bytes it memcpys in this case is zero, but it
is still undefined behaviour to copy zero bytes from a null pointer.
So check for this case explicitly.
libctf/ChangeLog
2021-03-25 Nick Alcock <nick.alcock@oracle.com>
PR libctf/27628
* ctf-serialize.c (ctf_emit_type_sect): Allow for a NULL vlen in
CTF_K_FUNCTION types.
This turns into a signed left shift by 31 bits, otherwise. This is an
offset and is always treated as unsigned in any case, so add an
appropriate cast.
include/ChangeLog
2021-03-25 Nick Alcock <nick.alcock@oracle.com>
PR libctf/27628
* ctf-api.h: Fix some indentation.
(CTF_SET_STID): Always do an unsigned shift, even if STID is
signed.
When we dump normal types, we emit their size and/or alignment:
but size and alignment dumping can return errors if the type is
part of a chain that terminates in a forward.
Emitting 0xffffffff as a size or alignment is unhelpful, so simply
skip emitting this info for any type for which size or alignment
checks return an error, no matter what the error is.
libctf/ChangeLog
2021-03-25 Nick Alcock <nick.alcock@oracle.com>
* ctf-dump.c (ctf_dump_format_type): Don't emit size or alignment
on error.
I ran into a new failure in gdb.base/gdb-caching-proc.exp:
FAIL: gdb.base/gdb-caching-proc.exp: supports_memtag: initial: memory-tag check
This is a failure from the `supports_memtag` proc added recently (this
new proc is in lib/gdb.exp).
The problem here is that `supports_memtag` is hitting one of the
default error cases in gdb_test_multiple, specifically it is finding a
$gdb_prompt left unmatched from an earlier call to gdb_test_multiple.
Looking back through the test output I found that the problem is the
proc `gnat_runtime_has_debug_info` in lib/ada.exp. This proc is not
matching the trailing $gdb_prompt. This leaves the prompt in the
expect buffer, then when we run `supports_memtag` it sees the prompt
and thinks that the test completed with no output.
Fixed by making use of `-wrap` in `gnat_runtime_has_debug_info` to
ensure the trailing prompt gets matched.
gdb/testsuite/ChangeLog:
* lib/ada.exp (gnat_runtime_has_debug_info): Use -wrap with
gdb_test_multiple.
To allow breakpoints to be created at invalid addresses,
target_read_code is used instead of read_code. This was fixed in
commit:
commit c01660c625
Date: Wed Apr 17 00:31:43 2019 +0100
gdb/riscv: Allow breakpoints to be created at invalid addresses
Unfortunately, the call to read_code was left in by mistake. The
result is that GDB will fail when trying to create the breakpoint,
rather than when trying to install the breakpoint (as is the case with
other targets).
This commit fixes this mistake and removes the offending call to
read_code.
gdb/ChangeLog:
* riscv-tdep.c (riscv_breakpoint_kind_from_pc): Remove call to
read_code.
The code was checking wrong bit for sign extension. It caused it
to zero-extend instead of sign-extend the immediate value.
2021-03-25 Abid Qadeer <abidh@codesourcery.com>
opcodes/
* nios2-dis.c (nios2_print_insn_arg): Fix sign extension of
immediate in br.n instruction.
gas/
* testsuite/gas/nios2/brn.s: New.
* testsuite/gas/nios2/brn.d: New.
In match_template() i.tm hasn't been filled yet, so it is necessarily t
which needs checking. This is only a latent issue as no other templates
with the same base_opcode have an extension_opcode of 1.
For VEX-encoded ones, all three involved vector registers have to be
distinct. For EVEX-encoded ones an actual mask register has to be in use
and zeroing-masking cannot be used (violation of either will #UD).
Additionally both involved vector registers have to be distinct for
EVEX-encoded gathers.
For INVLPGB the operand count was wrong (besides %edx there's also %ecx
which is an input to the insn). In this case I see little sense in
retaining the bogus 2-operand template. Plus swapping of the operands
wasn't properly suppressed for Intel syntax.
For PVALIDATE, RMPADJUST, and RMPUPDATE bogus single operand templates
were specified. These get retained, as the address operand is the only
one really needed to expressed non-default address size, but only for
compatibility reasons. Proper multi-operand insn get introduced and the
testcases get adjusted / extended accordingly.
While at it also drop the redundant definition of __amd64__ - we already
have x86_64 defined (or not) to distinguish 64-bit and non-64-bit cases.
This is only a partial fix for PR/gas 27419, in that it limits the bad
behavior of accepting mismatched operands to just x32 mode. The full fix
would be to revert commits 27f134698a and b3a3496f83, and to address
the issue in gcc instead.
The current_top_target function is a hidden dependency on the current
inferior. Since I'd like to slowly move towards reducing our dependency
on the global current state, remove this function and make callers use
current_inferior ()->top_target ()
There is no expected change in behavior, but this one step towards
making those callers use the inferior from their context, rather than
refer to the global current inferior.
gdb/ChangeLog:
* target.h (current_top_target): Remove, make callers use the
current inferior instead.
* target.c (current_top_target): Remove.
Change-Id: Iccd457036f84466cdaa3865aa3f9339a24ea001d
I noticed that dw2_map_matching_symbols does not use its 'kind'
parameter. This patch removes it. Tested by rebuilding.
2021-03-24 Tom Tromey <tom@tromey.com>
* dwarf2/read.c (dw2_map_matching_symbols): Update.
(dw2_expand_symtabs_matching_symbol): Remove 'kind' parameter.
(check_match, dw2_expand_symtabs_matching)
(dwarf2_debug_names_index::map_matching_symbols)
(dwarf2_debug_names_index::expand_symtabs_matching): Update.
Simon pointed out an error that I made in
compile_cplus_conver_struct_or_union in my original C++ compile submission:
if (type->code () == TYPE_CODE_STRUCT)
{
const char *what = TYPE_DECLARED_CLASS (type) ? "struct" : "class";
resuld = instance->plugin ().build_decl
(what, name.get (), (GCC_CP_SYMBOL_CLASS | nested_access
| (TYPE_DECLARED_CLASS (type)
? GCC_CP_FLAG_CLASS_NOFLAG
: GCC_CP_FLAG_CLASS_IS_STRUCT)),
0, nullptr, 0, filename, line);
}
Notice that WHAT will contain "struct" for TYPE_DECLARED_CLASS. Whoops.
Fortunately this first parameter of build_decl is only used for
debugging.
gdb/ChangeLog
2021-03-24 Keith Seitz <keiths@redhat.com>
* compile/compile-cplus-types.c
(compile_cplus_convert_struct_or_union): Fix TYPE_DECLARED_CLASS
thinko.
This variable was made static in:
6bd434d6ca ("gdb: make some variables static")
But I modified gdbarch.c instead of gdbarch.sh, so the change was
later reverted when gdbarch.c was re-generated.
Do it right this time.
gdb/ChangeLog:
* gdbarch.sh (gdbarch_data_registry): Make static.
* gdbarch.c: Re-generate.
Change-Id: I4048ba99a0cf47acd9da050934965db222fbd159
Add an AArch64-specific test and a more generic memory tagging test that
other architectures can run.
Even though architectures not supporting memory tagging can run the memory
tagging tests, the runtime check will make the tests bail out early, as it
would make no sense to proceed without proper support.
It is also tricky to do any further runtime tests for memory tagging, given
we'd need to deal with tags, and those are arch-specific. Therefore the
test in gdb.base is more of a smoke test.
If an architecture wants to implement memory tagging, then it makes sense to
have tests within gdb.arch instead.
gdb/testsuite/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* gdb.arch/aarch64-mte.c: New file.
* gdb.arch/aarch64-mte.exp: New test.
* gdb.base/memtag.c: New file.
* gdb.base/memtag.exp: New test.
* lib/gdb.exp (supports_memtag): New function.
Mention the new packets and memory tagging features.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* NEWS: Mention memory tagging changes.
Document the changes to the "print" and "x" commands to support memory
tagging.
gdb/doc/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* gdb.texinfo (Data): Document memory tagging changes to the "print"
command.
(Examining Memory): Document memory tagging changes to the "x"
command.
(Memory Tagging): Update with more information on changes to the "x"
and "print" commands.
Extend the "x" and "print" commands to make use of memory tagging
functionality, if supported by the architecture.
The "print" command will point out any possible tag mismatches it finds
when dealing with pointers, in case such a pointer is tagged. No additional
modifiers are needed.
Suppose we have a pointer "p" with value 0x1234 (logical tag 0x0) and that we
have an allocation tag of 0x1 for that particular area of memory. This is the
expected output:
(gdb) p/x p
Logical tag (0x0) does not match the allocation tag (0x1).
$1 = 0x1234
The "x" command has a new 'm' modifier that will enable displaying of
allocation tags alongside the data dump. It will display one allocation
tag per line.
AArch64 has a tag granule of 16 bytes, which means we can have one tag for
every 16 bytes of memory. In this case, this is what the "x" command will
display with the new 'm' modifier:
(gdb) x/32bxm p
<Allocation Tag 0x1 for range [0x1230,0x1240)>
0x1234: 0x01 0x02 0x00 0x00 0x00 0x00 0x00 0x00
0x123c: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
<Allocation Tag 0x1 for range [0x1240,0x1250)>
0x1244: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
0x124c: 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
(gdb) x/4gxm a
<Allocation Tag 0x1 for range [0x1230,0x1240)>
0x1234: 0x0000000000000201 0x0000000000000000
<Allocation Tag 0x1 for range [0x1240,0x1250)>
0x1244: 0x0000000000000000 0x0000000000000000
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* printcmd.c (decode_format): Handle the 'm' modifier.
(do_examine): Display allocation tags when required/supported.
(should_validate_memtags): New function.
(print_command_1): Display memory tag mismatches.
* valprint.c (show_memory_tag_violations): New function.
(value_print_option_defs): Add new option "memory-tag-violations".
(user_print_options) <memory_tag_violations>: Initialize to 1.
* valprint.h (struct format_data) <print_tags>: New field.
(value_print_options) <memory_tag_violations>: New field.
gdb/testsuite/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* gdb.base/options.exp: Adjust for new print options.
* gdb.base/with.exp: Likewise.
Document the new "memory-tag" command prefix and all of its subcommands.
gdb/doc/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* gdb.texinfo (Memory Tagging): New subsection and node.
(AArch64 Memory Tagging Extension): New subsection.
Add new commands under the "memory-tag" prefix to allow users to inspect,
modify and check memory tags in different ways.
The available subcommands are the following:
- memory-tag print-logical-tag <expression>: Prints the logical tag for a
particular address.
- memory-tag withltag <expression> <tag>: Prints the address tagged with the
logical tag <tag>.
- memory-tag print-allocation-tag <expression>: Prints the allocation tag for
a particular address.
- memory-tag setatag <expression> <length> <tags>: Sets one or more allocation
tags to the specified tags.
- memory-tag check <expression>: Checks if the logical tag in <address>
matches its allocation tag.
These commands make use of the memory tagging gdbarch methods, and are still
available, but disabled, when memory tagging is not supported by the
architecture.
I've pondered about a way to make these commands invisible when memory tagging
is not available, but given the check is at runtime (and support may come and go
based on a process' configuration), that is a bit too late in the process to
either not include the commands or get rid of them.
Ideas are welcome.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* printcmd.c: Include gdbsupport/rsp-low.h.
(memory_tag_list): New static global.
(process_print_command_args): Factored out of
print_command_1.
(print_command_1): Use process_print_command_args.
(show_addr_not_tagged, show_memory_tagging_unsupported)
(memory_tag_command, memory_tag_print_tag_command)
(memory_tag_print_logical_tag_command)
(memory_tag_print_allocation_tag_command, parse_with_logical_tag_input)
(memory_tag_with_logical_tag_command, parse_set_allocation_tag_input)
(memory_tag_set_allocation_tag_command, memory_tag_check_command): New
functions.
(_initialize_printcmd): Add "memory-tag" prefix and subcommands.
gdbsupport/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* rsp-low.cc (fromhex, hex2bin): Move to ...
* common-utils.cc: ... here.
(fromhex) Change error message text to not be RSP-specific.
* rsp-low.h (fromhex, hex2bin): Move to ...
* common-utils.h: ... here.
This patch handles the tagged_addr_ctrl register that is exported when
generating a core file.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* aarch64-linux-tdep.c
(aarch64_linux_iterate_over_regset_sections): Handle MTE register set.
* aarch64-linux-tdep.h (AARCH64_LINUX_SIZEOF_MTE_REGSET): Define.
Adds the AArch64-specific memory tagging support (MTE) by implementing the
required hooks and checks for GDBserver.
gdbserver/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* Makefile.in (SFILES): Add /../gdb/nat/aarch64-mte-linux-ptrace.c.
* configure.srv (aarch64*-*-linux*): Add arch/aarch64-mte-linux.o and
nat/aarch64-mte-linux-ptrace.o.
* linux-aarch64-low.cc: Include nat/aarch64-mte-linux-ptrace.h.
(class aarch64_target) <supports_memory_tagging>
<fetch_memtags, store_memtags>: New method overrides.
(aarch64_target::supports_memory_tagging)
(aarch64_target::fetch_memtags)
(aarch64_target::store_memtags): New methods.
Whenever a memory tag violation occurs, we get a SIGSEGV. Additional
information can be obtained through the siginfo data structure.
For AArch64 the Linux kernel may expose the fault address and tag
information, if we have a synchronous event. Otherwise there is
no fault address available.
The synchronous event looks like this:
--
(gdb) continue
Continuing.
Program received signal SIGSEGV, Segmentation fault
Memory tag violation while accessing address 0x0500fffff7ff8000
Allocation tag 0x1.
Logical tag 0x5
--
The asynchronous event looks like this:
--
(gdb) continue
Continuing.
Program received signal SIGSEGV, Segmentation fault
Memory tag violation
Fault address unavailable.
--
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* aarch64-linux-tdep.c
(aarch64_linux_report_signal_info): New function.
(aarch64_linux_init_abi): Register
aarch64_linux_report_signal_info as the report_signal_info hook.
* arch/aarch64-linux.h (SEGV_MTEAERR): Define.
(SEGV_MTESERR): Define.
Add some unit testing to exercise setting/getting logical tags in the
AArch64 implementation.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* aarch64-linux-tdep.c: Include gdbsupport/selftest.h.
(aarch64_linux_ltag_tests): New function.
(_initialize_aarch64_linux_tdep): Register aarch64_linux_ltag_tests.
The Linux kernel exposes the information about MTE-protected pages via the
proc filesystem, more specifically through the smaps file.
What we're looking for is a mapping with the 'mt' flag, which tells us that
mapping was created with a PROT_MTE flag and, thus, is capable of using memory
tagging.
We already parse that file for other purposes (core file
generation/filtering), so this patch refactors the code to make the parsing
of the smaps file reusable for memory tagging.
The function linux_address_in_memtag_page uses the refactored code to allow
querying for memory tag support in a particular address, and it gets used in the
next patch.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* linux-tdep.c (struct smaps_vmflags) <memory_tagging>: New flag
bit.
(struct smaps_data): New struct.
(decode_vmflags): Handle the 'mt' flag.
(parse_smaps_data): New function, refactored from
linux_find_memory_regions_full.
(linux_address_in_memtag_page): New function.
(linux_find_memory_regions_full): Refactor into parse_smaps_data.
* linux-tdep.h (linux_address_in_memtag_page): New prototype.
This is a quick cleanup that removes the use of fixed-length char arrays and
uses std::string instead.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* linux-tdep.c (linux_find_memory_regions_full): Use std::string
instead of char arrays.
The patch implements the memory tagging target hooks for AArch64, so we
can handle MTE.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* Makefile.in (ALL_64_TARGET_OBS): Add arch/aarch64-mte-linux.o.
(HFILES_NO_SRCDIR): Add arch/aarch64-mte-linux.h and
nat/aarch64-mte-linux-ptrace.h.
* aarch64-linux-nat.c: Include nat/aarch64-mte-linux-ptrace.h.
(aarch64_linux_nat_target) <supports_memory_tagging>: New method
override.
<fetch_memtags>: New method override.
<store_memtags>: New method override.
(aarch64_linux_nat_target::supports_memory_tagging): New method.
(aarch64_linux_nat_target::fetch_memtags): New method.
(aarch64_linux_nat_target::store_memtags): New method.
* arch/aarch64-mte-linux.c: New file.
* arch/aarch64-mte-linux.h: Include gdbsupport/common-defs.h.
(AARCH64_MTE_GRANULE_SIZE): Define.
(aarch64_memtag_type): New enum.
(aarch64_mte_get_tag_granules): New prototype.
* configure.nat (NATDEPFILES): Add nat/aarch64-mte-linux-ptrace.o.
* configure.tgt (aarch64*-*-linux*): Add arch/aarch64-mte-linux.o.
* nat/aarch64-mte-linux-ptrace.c: New file.
* nat/aarch64-mte-linux-ptrace.h: New file.
This patch adds the required ptrace request definitions into a new include
file that will be used by the next patches.
They are PTRACE_PEEKMTETAGS and PTRACE_POKEMTETAGS.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* Makefile.in (HFILES_NO_SRCDIR): Add nat/aarch64-mte-linux-ptrace.h.
* nat/aarch64-mte-linux-ptrace.h: New file.
AArch64 MTE support in the Linux kernel exposes a new register
through ptrace. This patch adds the required code to support it.
include/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* elf/common.h (NT_ARM_TAGGED_ADDR_CTRL): Define.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* aarch64-linux-nat.c (fetch_mteregs_from_thread): New function.
(store_mteregs_to_thread): New function.
(aarch64_linux_nat_target::fetch_registers): Update to call
fetch_mteregs_from_thread.
(aarch64_linux_nat_target::store_registers): Update to call
store_mteregs_to_thread.
* aarch64-tdep.c (aarch64_mte_register_names): New struct.
(aarch64_cannot_store_register): Handle MTE registers.
(aarch64_gdbarch_init): Initialize and setup MTE registers.
* aarch64-tdep.h (gdbarch_tdep) <mte_reg_base>: New field.
<has_mte>: New method.
* arch/aarch64-linux.h (AARCH64_LINUX_SIZEOF_MTE): Define.
gdbserver/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* linux-aarch64-low.cc (aarch64_fill_mteregset): New function.
(aarch64_store_mteregset): New function.
(aarch64_regsets): Add MTE register set entry.
(aarch64_sve_regsets): Add MTE register set entry.
This patch adds a target description and feature "mte" for aarch64.
It includes one new register, tag_ctl, that can be used to configure the
tag generation rules and sync/async modes. It is 64-bit in size.
The patch also adjusts the code that creates the target descriptions at
runtime based on CPU feature checks.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* aarch64-linux-nat.c
(aarch64_linux_nat_target::read_description): Take MTE flag into
account.
Slight refactor to hwcap flag checking.
* aarch64-linux-tdep.c
(aarch64_linux_core_read_description): Likewise.
* aarch64-tdep.c (tdesc_aarch64_list): Add one more dimension for
MTE.
(aarch64_read_description): Add mte_p parameter and update to use it.
Update the documentation.
(aarch64_gdbarch_init): Update call to aarch64_read_description.
* aarch64-tdep.h (aarch64_read_description): Add mte_p parameter.
* arch/aarch64.c: Include ../features/aarch64-mte.c.
(aarch64_create_target_description): Add mte_p parameter and update
the code to use it.
* arch/aarch64.h (aarch64_create_target_description): Add mte_p
parameter.
* features/Makefile (FEATURE_XMLFILES): Add aarch64-mte.xml.
* features/aarch64-mte.c: New file, generated.
* features/aarch64-mte.xml: New file.
gdbserver/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* linux-aarch64-ipa.cc (get_ipa_tdesc): Update call to
aarch64_linux_read_description.
(initialize_low_tracepoint): Likewise.
* linux-aarch64-low.cc (aarch64_target::low_arch_setup): Take MTE flag
into account.
* linux-aarch64-tdesc.cc (tdesc_aarch64_list): Add one more dimension
for MTE.
(aarch64_linux_read_description): Add mte_p parameter and update to
use it.
* linux-aarch64-tdesc.h (aarch64_linux_read_description): Add mte_p
parameter.
This patch is a preparation for the next patches implementing MTE. It just adds
a HWCAP2 constant for MTE, creates a new generic arch/aarch64-mte-linux.h file
and includes that file in the source files that will use it.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* Makefile.in (HFILES_NO_SRCDIR): Add arch/aarch64-mte-linux.h.
* aarch64-linux-nat.c: Include arch/aarch64-mte-linux.h.
* aarch64-linux-tdep.c: Likewise
* arch/aarch64-mte-linux.h: New file.
gdbserver/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* linux-aarch64-low.cc: Include arch/aarch64-mte-linux.h.
Document the remote packet changes to support memory tagging.
gdb/doc/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* gdb.texinfo (General Query Packets): Document qMemTags and
QMemTags. Document the "memory-tagging" feature.
(ARM-Specific Protocol Details): Document memory tag types.
Add some unit testing to exercise the functions handling the qMemTags and
QMemTags packets as well as feature support.
gdbserver/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* server.cc (test_memory_tagging_functions): New function.
(captured_main): Register test_memory_tagging_functions.
This patch adds the generic remote bits to gdbserver so it can check for memory
tagging support and handle fetch tags and store tags requests.
gdbserver/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* remote-utils.cc (decode_m_packet_params): Renamed from ...
(decode_m_packet): ... this, which now calls decode_m_packet_params.
Make char * param/return const char *.
(decode_M_packet): Use decode_m_packet_params and make char * param
const char *.
* remote-utils.h (decode_m_packet_params): New prototype.
(decode_m_packet): Constify char pointers.
(decode_M_packet): Likewise.
* server.cc (create_fetch_memtags_reply)
(parse_store_memtags_request): New
functions.
(handle_general_set): Handle the QMemTags packet.
(parse_fetch_memtags_request): New function.
(handle_query): Handle the qMemTags packet and advertise memory
tagging support.
(captured_main): Initialize memory tagging flag.
* server.h (struct client_state): Initialize memory tagging flag.
* target.cc (process_stratum_target::supports_memory_tagging)
(process_stratum_target::fetch_memtags)
(process_stratum_target::store_memtags): New methods.
* target.h: Include gdbsupport/byte-vector.h.
(class process_stratum_target) <supports_memory_tagging>
<fetch_memtags, store_memtags>: New class virtual methods.
(target_supports_memory_tagging): Define.
Include some unit testing for the functions handling the new qMemTags and
QMemTags packets.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* remote: Include gdbsupport/selftest.h.
(test_memory_tagging_functions): New function.
(_initialize_remote): Register test_memory_tagging_functions.
This patch adds memory tagging support to GDB's remote side, with
packet string checks, new packet support and an implementation of
the two new tags methods fetch_memtags and store_memtags.
GDBserver needs to know how to read/write allocation tags, since that is
done via ptrace. It doesn't need to know about logical tags.
The new packets are:
qMemTags:<address>,<length>:<type>
--
Reads tags of the specified type from the address range
[<address>, <address + length>)
QMemTags:<address>,<length>:<type>:<uninterpreted tag bytes>
--
Writes the tags of specified type represented by the uninterpreted bytes to
the address range [<address>, <address + length>).
The interpretation of what to do with the tag bytes is up to the arch-specific
code.
Note that these new packets consider the case of packet size overflow as an
error, given the common use case is to read/write only a few memory tags at
a time. Having to use a couple new packets for multi-part transfers wouldn't
make sense for the little use it would have.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* remote.c (PACKET_memory_tagging_feature): New enum.
(remote_memory_tagging_p): New function.
(remote_protocol_features): New "memory-tagging" entry.
(remote_target::remote_query_supported): Handle memory tagging
support.
(remote_target::supports_memory_tagging): Implement.
(create_fetch_memtags_request, parse_fetch_memtags_reply)
(create_store_memtags_request): New functions.
(remote_target::fetch_memtags): Implement.
(remote_target::store_memtags): Implement.
(_initialize_remote): Add new "memory-tagging-feature"
config command.
We need some new gdbarch hooks to help us manipulate memory tags without having
to have GDB call the target methods directly.
This patch adds the following hooks:
gdbarch_memtag_to_string
--
Returns a printable string corresponding to the tag.
gdbarch_tagged_address_p
--
Checks if a particular address is protected with memory tagging.
gdbarch_memtag_matches_p
--
Checks if the logical tag of a pointer and the allocation tag from the address
the pointer points to matches.
gdbarch_set_memtags:
--
Sets either the allocation tag or the logical tag for a particular value.
gdbarch_get_memtag:
--
Gets either the allocation tag or the logical tag for a particular value.
gdbarch_memtag_granule_size
--
Sets the memory tag granule size, which represents the number of bytes a
particular allocation tag covers. For example, this is 16 bytes for
AArch64's MTE.
I've used struct value as opposed to straight CORE_ADDR so other architectures
can use the infrastructure without having to rely on a particular type for
addresses/pointers. Some architecture may use pointers of 16 bytes that don't
fit in a CORE_ADDR, for example.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* arch-utils.c (default_memtag_to_string, default_tagged_address_p)
(default_memtag_matches_p, default_set_memtags)
(default_get_memtag): New functions.
* arch-utils.h (default_memtag_to_string, default_tagged_address_p)
(default_memtag_matches_p, default_set_memtags)
(default_get_memtag): New prototypes.
* gdbarch.c: Regenerate.
* gdbarch.h: Regenerate.
* gdbarch.sh (memtag_to_string, tagged_address_p, memtag_matches_p)
(set_memtags, get_memtag, memtag_granule_size): New gdbarch hooks.
(enum memtag_type): New enum.
This patch starts adding some of the generic pieces to accomodate memory
tagging.
We have three new target methods:
- supports_memory_tagging: Checks if the target supports memory tagging. This
defaults to false for targets that don't support memory tagging.
- fetch_memtags: Fetches the allocation tags associated with a particular
memory range [address, address + length).
The default is to return 0 without returning any tags. This should only
be called if memory tagging is supported.
- store_memtags: Stores a set of allocation tags for a particular memory
range [address, address + length).
The default is to return 0. This should only
be called if memory tagging is supported.
gdb/ChangeLog:
2021-03-24 Luis Machado <luis.machado@linaro.org>
* remote.c (remote_target) <supports_memory_tagging>: New method
override.
<fetch_memtags>: New method override.
<store_memtags>: New method override.
(remote_target::supports_memory_tagging): New method.
(remote_target::fetch_memtags): New method.
(remote_target::store_memtags): New method.
* target-delegates.c: Regenerate.
* target.h (struct target_ops) <supports_memory_tagging>: New virtual
method.
<fetch_memtags>: New virtual method.
<store_memtags>: New virtual method.
(target_supports_memory_tagging): Define.
(target_fetch_memtags): Define.
(target_store_memtags): Define.
* target-debug.h (target_debug_print_size_t)
(target_debug_print_const_gdb_byte_vector_r)
(target_debug_print_gdb_byte_vector_r): New functions.
In the majority of cases we can easily determine the length from the
encoding, irrespective of whether a prefix is specified there as well.
We further don't even need to record the value in the table entries, as
it's easy enough to determine it (without any guesswork, unless an insn
with major opcode 00 appeared that requires a 2nd opcode byte to be
specified explicitly) when installing the chosen template for further
processing.
Should an encoding appear which
- has a major opcode byte of 66, F3, or F2,
- requires a 2nd opcode byte to be specified explicitly,
- doesn't have a mandatory prefix
we'd need to convert all templates presently encoding a mandatory prefix
this way to the Prefix_0X<nn> model to eliminate the respective guessing
i386-gen does.
Just like is already done for legacy encoded insns, record the mandatory
prefix information in the respective opcode modifier field. Do this
without changing the source table, but rather by deriving the values from
their existing source representation.
This is in preparation of opcode_length going away as a field in the
templates. Identify pseudo prefixes by a base opcode of zero instead:
No real prefix has an opcode of zero. This at the same time allows
dropping a curious special case from i386-gen.
Since most attributes are identical for all pseudo prefixes, take the
opportunity and also template them.
In preparation to use PREFIX_0X<nn> attributes also in VEX/XOP/EVEX
encoding templates, renumber the pseudo-enumerators such that their
values can then also be used directly in the respective prefix bit
fields.
