Since GDB now requires C++17, we don't need the internally maintained
gdb::optional implementation. This patch does the following replacing:
- gdb::optional -> std::optional
- gdb::in_place -> std::in_place
- #include "gdbsupport/gdb_optional.h" -> #include <optional>
This change has mostly been done automatically. One exception is
gdbsupport/thread-pool.* which did not use the gdb:: prefix as it
already lives in the gdb namespace.
Change-Id: I19a92fa03e89637bab136c72e34fd351524f65e9
Approved-By: Tom Tromey <tom@tromey.com>
Approved-By: Pedro Alves <pedro@palves.net>
gdb::make_unique is a wrapper around std::make_unique when compiled with
C++17. Now that C++17 is required, use std::make_unique directly in the
codebase, and remove gdb::make_unique.
Change-Id: I80b615e46e4b7c097f09d78e579a9bdce00254ab
Approved-By: Tom Tromey <tom@tromey.com>
Approved-By: Pedro Alves <pedro@palves.net
common-defs.h has a few defines that I suspect were used during the
transition to C++. These aren't needed any more, so remove them.
Tested by rebuilding.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Approved-By: Andrew Burgess <aburgess@redhat.com>
This header is only suitable for use on x86 hosts and is only included
there, so these fallbacks should not be needed.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
__SVE_VQ_BYTES is only available if SVE definitions are available in
the system's headers, and this is not true for all systems.
For this purpose, we define SVE_VQ_BYTES. This patch fixes the
name of the constant being used.
SME2 defines a new 512-bit register named ZT0, and it is only available
if SME is also supported. The ZT0 state is valid only if the SVCR ZA bit
is enabled. Otherwise its contents are empty (0).
The target description is dynamic and gets generated at runtime based on the
availability of the feature.
Validated under Fast Models.
Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
Teach gdb about the ZA/SSVE state on signal frames and how to restore
the contents of the registers.
There is a new ZA_MAGIC context that the Linux Kernel uses to communicate
the ZA register state to gdb.
The SVE_MAGIC context has also been adjusted to contain a flag indicating
whether it is a SVE or SSVE state.
Regression-tested on aarch64-linux Ubuntu 22.04/20.04.
Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
The SME (Scalable Matrix Extension) [1] exposes a new matrix register ZA with
variable sizes. It also exposes a new mode called streaming mode.
Similarly to SVE, the ZA register size is dictated by a vector length, but the
SME vector length is called streaming vetor length. The total size for
ZA in a given moment is svl x svl.
In streaming mode, the SVE registers have their sizes based on svl rather than
the regular vector length (vl).
The feature detection is controlled by the HWCAP2_SME bit, but actual support
should be validated by attempting a ptrace call for one of the new register
sets: NT_ARM_ZA and NT_ARM_SSVE.
Due to its large size, the ZA register is exposed as a vector of bytes, but we
introduce a number of pseudo-registers that gives various different views
into the ZA contents. These can be arranged in a couple categories: tiles and
tile slices.
Tiles are matrices the same size or smaller than ZA. Tile slices are vectors
which map to ZA's rows/columns in different ways.
A new dynamic target description is provided containing the ZA register, the SVG
register and the SVCR register. The size of ZA, like the SVE vector registers,
is based on the vector length register SVG (VG for SVE).
This patch enables SME register support for gdb.
[1] https://community.arm.com/arm-community-blogs/b/architectures-and-processors-blog/posts/scalable-matrix-extension-armv9-a-architecture
Co-Authored-By: Ezra Sitorus <ezra.sitorus@arm.com>
Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
This is a patch in preparation to upcoming patches enabling SME support. It
attempts to simplify the gdb/gdbserver shared interface used to read/write
SVE registers.
Where the current code makes use of unique_ptr, allocating a new buffer by
hand and passing a buffer around, this patch makes that code use
gdb::byte_vector and passes a reference to this byte vector to the functions,
allowing the functions to have ready access to the size of the buffer.
It also shares a bit more code between gdb and gdbserver, in particular around
handling of ptrace get/set requests for SVE.
I think gdbserver could be refactored to handle register reads/writes more
like gdb's native layer as opposed to letting the generic linux-low layer do
the ptrace calls. This is not very flexible and assumes one size for the
responses. If you have something like NT_ARM_SVE, where you can have either
FPSIMD or SVE contents, it doesn't work that well.
I didn't want to change that interface right now as it is a bit too much work
and touches all the targets, some of which I can't easily test.
Hence the reason why the buffer the generic linux-now passes down to
linux-aarch64-low is unused or ignored.
No user-visible changes should happen as part of this refactor other than a
slightly reworded warning message.
While doing the refactor, I also noticed what seems to be a mistake in checking
if the register cache contains active (non-zero) SVE data.
For instance, the original code did something like this in
aarch64_sve_regs_copy_from_reg_buf:
has_sve_state |= reg_buf->raw_compare (AARCH64_SVE_Z0_REGNUM + i
reg, sizeof (__int128_t));
"reg" is a zeroed-out buffer that we compare the Z register contents
past the first 128 bits. The problem here is that raw_compare returns
1 if the contents compare the same, which means has_sve_state will be
true. But if we compared the Z register contents to 0, it means we
*do not* have SVE state, and therefore has_sve_state should be false.
The consequence of this mistake is that we convert the initial
FPSIMD-formatted data we get from ptrace for the NT_ARM_SVE register
set to a SVE-formatted one.
In the end, this doesn't cause user-visible differences because the
values of both the Z and V registers will still be the same. But the
logic is not correct.
I used the opportunity to fix this, and it gets tested later on by
the additional SME tests.
I do plan on submitting some SVE-specific tests to make sure we have
a bit more coverage in GDB's testsuite.
Regression-tested on aarch64-linux Ubuntu 22.04/20.04.
Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
In preparation to the SME support patches, rename the SVE-specific files to
something a bit more meaningful that can be shared with the SME code.
In this case, I've renamed the "sve" in the names to "scalable".
No functional changes.
Regression-tested on aarch64-linux Ubuntu 22.04/20.04.
Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
Since commit b42405a159 ("gdb: Update x86 Linux architectures to
support XSAVE layouts."), the test gdb.base/gcore.exp fails on my AMD
Ryzen 3700X machine:
FAIL: gdb.base/gcore.exp: corefile restored all registers
The test gets the register state (saves the output of "info
all-registers"), saves a core with the "gcore" command, loads the core,
and checks the register state against the one previously saved. The
problem is that when reading registers from the core file, the last half
of ymm registers is unavailable:
(gdb) print $ymm0.v32_int8
$1 = {0, -77, -23, -9, -1, 127, 0, 0, 0, -77, -23, -9, -1, 127, 0, 0, <unavailable> <repeats 16 times>}
One strange thing with this machine is that the bitset of state
components supported by XCR0 is 0x207, meaning "x87 | SSE | AVX | PKRU",
but XCR0 at runtime is 0x7, meaning "x87 | SSE | AVX". So, PKRU appears
to be supported by the processor, but disabled by the kernel. I didn't
find why yet.
From CPUID leaf EAX=0Dh, ECX=00h, GDB can get:
- from EBX: max size of the XSAVE area required by features currently
enabled in XCR0. On my machine, it's 0x340 (832).
- from ECX: max size of the XSAVE area required by all features
supported by XCR0. On my machine, it's 0x380 (896).
At runtime, GDB uses ECX (max size required by all supported features)
to fill the x86_xsave_layout::sizeof_xsave. So, when writing the core
file note for the XSAVE state, it writes a note of size 896, even though
it doesn't write the PKRU state. When loading back the core, GDB tries
to figure out the layout of the XSAVE area based on what features are
enabled in XCR0 and the size of the note (the size of the XSAVE area).
Since my combination of XCR0 and size of XSAVE area doesn't match any
combination known by GDB, GDB falls back to a gdbarch supporting only
x87 and SSE.
This patch changes GDB to populate the x86_xsave_layout::sizeof_xsave
field (and consequently the size of the XSAVE state note in core files)
using EBX, the size of the XSAVE area required by currently enabled
features in XCR0. This makes i387_guess_xsave_layout recognize my case
with this condition:
else if (HAS_AVX (xcr0) && xsave_size == 832)
{
/* Intel and AMD CPUs supporting AVX. */
layout.avx_offset = 576;
}
In other words, just as if my machine didn't support PKRU at all.
Another reason why I think this change makes sense is that XSAVE state
notes in kernel-generated cores on this machine have size 832. So this
change makes GDB-generated cores more similar to kernel-generated ones,
reducing the diversity of XSAVE state notes that GDB needs to be able to
figure out.
Note that if PKRU was enabled on my machine, then the effective XSAVE
area size would be 896 bytes. We would need to add a case in
i387_guess_xsave_layout for that combination, since there is no
currently. But I don't have a way to test that right now, since I don't
know why PKRU is disabled.
Relevant review note from John Baldwin:
One further note is that the Linux x86 arches use x86_xsave_length()
to infer ("guess") the size of the XSAVE register set that the Linux
kernel writes out in core dumps. On FreeBSD x86 arches, GDB is able
to query this size directly from the kernel via ptrace. My use of ECX
for this guess earlier was just not the best guess. In the case that
the kernel enables all of the available features, then ECX and EBX
have the same values, so this only matters for a system where the
kernel has enabled a subset of available XSAVE extensions.
Change-Id: If64f30307f3a2e5ca3e1fd1cb7379ea840805a85
Reviewed-By: John Baldwin <jhb@FreeBSD.org>
I noticed a comment by an include and remembered that I think these
don't really provide much value -- sometimes they are just editorial,
and sometimes they are obsolete. I think it's better to just remove
them. Tested by rebuilding.
Approved-By: Andrew Burgess <aburgess@redhat.com>
Following the example of private_thread_info and private_inferior, turn
struct btrace_target_info into a small class hierarchy.
Also merge btrace_tinfo_bts with btrace_tinfo_pt and inline into
linux_btrace_target_info.
Fixes PR gdb/30751.
When running test-case gdb.arch/i386-avx512.exp, I run into:
...
gdb compile failed, In file included from gdb.arch/i386-avx512.c:20:0:
src/gdb/nat/x86-cpuid.h: In function 'x86_cpuid_count':
src/gdb/nat/x86-cpuid.h:63:16: error: \
'nullptr' undeclared (first use in this function)
if (__eax == nullptr)
^~~~~~~
src/gdb/nat/x86-cpuid.h:63:16: note: each \
undeclared identifier is reported only once for each function it appears in
=== gdb Summary ===
# of untested testcases 1
...
This is due to commit e85aad4ae7 ("nat/x86-cpuid.h: Add x86_cpuid_count
wrapper around __get_cpuid_count"), which introduced the nullptr check.
The header file gdb/nat/x86-cpuid.h is a file that is included in the build
and compiled as a C++ file, but also in the testsuite and compiled as a C
file.
Fix this by replacing nullptr with (void *)0.
Tested on x86_64-linux.
Co-Authored-By: Kevin Buettner <kevinb@redhat.com>
Approved-by: Kevin Buettner <kevinb@redhat.com>
x86_xsave_length returns the total length of the XSAVE state area
standard format as queried from CPUID.
x86_fetch_xsave_layout uses CPUID to query the offsets of XSAVE
extended regions from the running host. The total length of the XSAVE
state area can either be supplied by the caller if known (e.g. from
FreeBSD's PT_GETXSTATEINFO) or it can be queried from the running host
using x86_xsave_length.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
I found some code in linux-osdata that manually managed a string.
Replacing this with std::string simplifies it.
Reviewed-by: John Baldwin <jhb@FreeBSD.org>
Caught this during emulator testing.
Fix the constants. They should be 0xa and 0xb as opposed to 0x10 and
0x11. There was a thinko while defining them.
Obvious enough.
Tested on aarch64-linux Ubuntu 20.04/22.04.
Teach gdb about a new debug architecture version for AArch64 (0x11).
No user-visible changes.
Regression-tested on aarch64-linux Ubuntu 20.04/22.04.
Signed-off-by: Luis Machado <luis.machado@arm.com>
The Arm Architecture Reference Manual defines debug version 0b1010 for
FEAT_Debugv8p8. This is used to identify valid hardware debug registers.
gdb currently only knows about versions up to FEAT_Debugv8p4. This patch
teaches gdb about this new version.
No visible changes should happen as consequence of this patch, but in the
future gdb will be able to identify debug registers in newer hardware.
Regression-tested on aarch64-linux Ubuntu 20.04/22.04.
The detection logic for TPIDR2 was implemented incorrectly. Originally
the detection was supposed to be through a ptrace error code, but in reality,
for backwards compatibility, the detection should be based on the size of
the returned iovec.
For instance, if a target supports both TPIDR and TPIDR2, ptrace will return a
iovec size of 16. If a target only supports TPIDR and not TPIDR2, it will
return a iovec size of 8, even if we asked for 16 bytes.
This patch fixes this issue in code that is shared between gdb and gdbserver,
therefore both gdb and gdbserver are fixed.
Tested on AArch64/Linux Ubuntu 20.04.
I've long wanted to remove 'struct buffer', and thanks to Simon's
earlier patch, I was finally able to do so. My feeling has been that
gdb already has several decent structures available for growing
strings: std::string of course, but also obstack and even objalloc
from BFD and dyn-string from libiberty. The previous patches in this
series removed all the uses of struct buffer, so this one can remove
the code and the remaining #includes.
This commit is the result of running the gdb/copyright.py script,
which automated the update of the copyright year range for all
source files managed by the GDB project to be updated to include
year 2023.
This allows to build GDB even though the default value of
_WIN32_WINNT is lower than the one needed to expose some
new APIs used here, and leave the test for their actual
support to run time.
* gdb/nat/windows-nat.c (EXTENDED_STARTUPINFO_PRESENT): Define if
not defined.
(create_process_wrapper): Use 'gdb_lpproc_thread_attribute_list'
instead of 'PPROC_THREAD_ATTRIBUTE_LIST' (which might not be defined
at compile time). This fixes compilation error using mingw.org's
MinGW.
Replace the use of struct buffer in linux-osdata.c with std::string.
There is no change in the logic, so there should be no user-visible
change.
Change-Id: I27f53165d401650bbd0bebe8ed88221e25545b3f
Approved-By: Pedro Alves <pedro@palves.net>
With the AArch64 Scalable Matrix Extension we have a new TPIDR2 register, and
it will be added to the existing NT_ARM_TLS register set. Kernel patches are
being reviewed here:
https://lore.kernel.org/linux-arm-kernel/20220818170111.351889-1-broonie@kernel.org/
From GDB's perspective, we handle it in a similar way to the existing TPIDR
register. But we need to consider cases of systems that only have TPIDR and
systems that have both TPIDR and TPIDR2.
With that in mind, the following patch adds the required code to support
TPIDR2 and turns the org.gnu.gdb.aarch64.tls feature into a
dynamically-generated target description as opposed to a static target
description containing only TPIDR.
That means we can remove the gdb/features/aarch64-tls.xml file and replace the
existing gdb/features/aarch64-tls.c auto-generated file with a new file that
dynamically generates the target description containing either TPIDR alone or
TPIDR and TPIDR2.
In the future, when *BSD's start to support this register, they can just
enable it as is being done for the AArch64 Linux target.
The core file read/write code has been updated to support TPIDR2 as well.
On GDBserver's side, there is a small change to the find_regno function to
expose a non-throwing version of it.
It always seemed strange to me how find_regno causes the whole operation to
abort if it doesn't find a particular register name. The patch moves code
from find_regno into find_regno_no_throw and makes find_regno call
find_regno_no_throw instead.
This allows us to do register name lookups to find a particular register
number without risking erroring out if nothing is found.
The patch also adjusts the feature detection code for aarch64-fbsd, since
the infrastructure is shared amongst all aarch64 targets. I haven't added
code to support TPIDR2 in aarch64-fbsd though, as I'm not sure when/if
that will happen.
I get this test failure on my CI;
FAIL: gdb.base/info-os.exp: get process list
The particularity of this setup is that builds are done in containers
who are allocated 4 CPUs on a machine that has 40. The code in
nat/linux-osdata.c fails to properly fetch the core number for each
task.
linux_xfer_osdata_processes uses `sysconf (_SC_NPROCESSORS_ONLN)`, which
returns 4, so it allocates an array of 4 integers. However, the core
numbers read from /proc/pid/task/tid/stat, by function
linux_common_core_of_thread, returns a value anywhere between 0 and 39.
The core numbers above 3 are therefore ignored, many processes end up
with no core value, and the regexp in the test doesn't match (it
requires an integer as the core field).
The way this the CPUs are exposed to the container is that the container
sees 40 CPUs "present" and "possible", but only 4 arbitrary CPUs
actually online:
root@ci-node-jammy-amd64-04-08:~# cat /sys/devices/system/cpu/present
0-39
root@ci-node-jammy-amd64-04-08:~# cat /sys/devices/system/cpu/online
5,11,24,31
root@ci-node-jammy-amd64-04-08:~# cat /sys/devices/system/cpu/possible
0-39
The solution proposed in this patch is to find out the number of
possible CPUs using /sys/devices/system/cpu/possible. In practice, this
will probably always contain `0-N`, where N is the number of CPUs, minus
one. But the documentation [1] doesn't such guarantee, so I'll assume
that it can contain a more complex range list such as `2,4-31,32-63`,
like the other files in that directory can have. The solution is to
iterate over these numbers to find the highest possible CPU id, and
use that that value plus one as the size of the array to allocate.
[1] https://www.kernel.org/doc/Documentation/admin-guide/cputopology.rst
Change-Id: I7abce2e43b000c1327fa94cd7b99d46e49d7ccf3
I would like to add more code to nat/linux-osdata.c that reads an entire
file from /proc or /sys and processes it as a string afterwards. I
would like to avoid duplicating the somewhat error-prone code that reads
an entire file to a buffer. I think we should have a utility function
that does that.
Add read_file_to_string to gdbsupport/filestuff.{c,h}, and make
linux_common_core_of_thread use it. I want to make the new function
return an std::string, and because strtok doesn't play well with
std::string (it requires a `char *`, std::string::c_str returns a `const
char *`), change linux_common_core_of_thread to use std::string methods
instead.
Approved-By: Tom Tromey <tom@tromey.com>
Change-Id: I1793fda72a82969c28b944a84acb953f74c9230a
Absent _UNICODE being defined (which gdb's Makefile doesn't do),
windows.h will always define STARTUPINFO is as STARTUPINFOA, so this
cast isn't correct when create_process expects a STARTUPINFOW
parameter (i.e. in a Cygwin build).
Instead write this as &info_ex.StartupInfo (which is always of the
correct type).
In gdb/nat/linux-btrace.c:btrace_this_cpu() we initialize the cpu
structure given to the libipt btrace decoder.
We only consider the extended model field for family 0x6 and forget about
family 0xf and we don't consider the extended family field. Fix it.
Currently, every internal_error call must be passed __FILE__/__LINE__
explicitly, like:
internal_error (__FILE__, __LINE__, "foo %d", var);
The need to pass in explicit __FILE__/__LINE__ is there probably
because the function predates widespread and portable variadic macros
availability. We can use variadic macros nowadays, and in fact, we
already use them in several places, including the related
gdb_assert_not_reached.
So this patch renames the internal_error function to something else,
and then reimplements internal_error as a variadic macro that expands
__FILE__/__LINE__ itself.
The result is that we now should call internal_error like so:
internal_error ("foo %d", var);
Likewise for internal_warning.
The patch adjusts all calls sites. 99% of the adjustments were done
with a perl/sed script.
The non-mechanical changes are in gdbsupport/errors.h,
gdbsupport/gdb_assert.h, and gdb/gdbarch.py.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Change-Id: Ia6f372c11550ca876829e8fd85048f4502bdcf06
When working on windows-nat.c, it's useful to see an error message in
addition to the error number given by GetLastError. This patch moves
strwinerror from gdbserver to gdbsupport, and then updates
windows-nat.c to use it. A couple of minor changes to strwinerror
(constify the return type and use the ARRAY_SIZE macro) are also
included.
On a machine with gcc 12, I get this warning:
CXX nat/linux-btrace.o
In function ‘btrace_error linux_read_bts(btrace_data_bts*, btrace_target_info*, btrace_read_type)’,
inlined from ‘btrace_error linux_read_btrace(btrace_data*, btrace_target_info*, btrace_read_type)’ at ../gdb/nat/linux-btrace.c:935:29:
../gdb/nat/linux-btrace.c:865:21: warning: ‘data_head’ may be used uninitialized [-Wmaybe-uninitialized]
865 | pevent->last_head = data_head;
| ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
../gdb/nat/linux-btrace.c: In function ‘btrace_error linux_read_btrace(btrace_data*, btrace_target_info*, btrace_read_type)’:
../gdb/nat/linux-btrace.c:792:9: note: ‘data_head’ was declared here
792 | __u64 data_head, data_tail;
| ^~~~~~~~~
Fix this by initializing the 'data_head' variable.
Tested by rebuilding on x86_64 openSUSE Tumbleweed with gcc 12.
This changes windows_process_info to use virtual methods for its
callbacks, and then changes the two clients of this code to subclass
this class to implement the methods.
I considered using CRTP here, but that would require making the new
structures visible to the compilation of of nat/windows-nat.c. This
seemed like a bit of a pain, so I didn't do it.
This change then lets us change all the per-inferior globals to be
members of the new subclass. Note that there can still only be a
single inferior -- currently there's a single global of the new type.
This is just another step toward possibly implementing multi-inferior
for Windows.
It's possible this could be cleaned up further... ideally I'd like to
move more of the data into the base class. However, because gdb
supports Cygwin and gdbserver does not, and because I don't have a way
to build or test Cygwin, larger refactorings are difficult.
On Windows, it is possible to disable ASLR when creating a process.
This patch adds code to do this, and hooks it up to gdb's existing
disable-randomization feature. Because the Windows documentation
cautions that this isn't available on all versions of Windows, the
CreateProcess wrapper function is updated to make the attempt, and
then fall back to the current approach if it fails.
Fix Cygwin build after 0578e87f ("Remove some globals from
nat/windows-nat.c"). Update code under ifdef __CYGWIN__ for globals
moved to members of struct windows_process_info.
Fix Cygwin build after fcab5839 ("Implement pid_to_exec_file for Windows
in gdbserver"). That change moves code from gdb/windows-nat.c to
gdb/nat/windows-nat.c, but doesn't add the required typedefs and
includes for parts of that code under ifdef __CYGWIN__.
I noticed that gdbserver did not implement pid_to_exec_file for
Windows, while gdb did implement it. This patch moves the code to
nat/windows-nat.c, so that it can be shared. This makes the gdbserver
implementation trivial.
This changes target_pid_to_exec_file and target_ops::pid_to_exec_file
to return a "const char *". I couldn't build many of these targets,
but did examine the code by hand -- also, as this only affects the
return type, it's normally pretty safe. This brings gdb and gdbserver
a bit closer, and allows for the removal of a const_cast as well.
I noticed a few spots in GDB that use "typedef enum". However, in C++
this isn't as useful, as the tag is automatically entered as a
typedef. This patch removes most uses of "typedef enum" -- the
exceptions being in some nat-* code I can't compile, and
glibc_thread_db.h, which I think is more or less a copy of some C code
from elsewhere.
Tested by rebuilding.
Internally at AdaCore, we noticed that the new Windows thread name
code could fail. First, it might return a zero-length string, but in
gdb conventions it should return nullptr instead. Second, an encoding
failure could wind up showing replacement characters to the user; this
is confusing and not useful; it's better to recognize such errors and
simply discard the name. This patch makes both of these changes.
Windows 10 introduced SetThreadDescription and GetThreadDescription, a
simpler way to set a thread's name. This changes gdb and gdbserver to
use this convention when it is available.
This is part of PR win32/29050.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29050
