I noticed in emit_ops_insns in gdbserver/linux-aarch64-low.cc:
...
threads_debug_printf ("Adding %d instrucions at %s",
...
Fix the typo by using "instructions" instead.
Reviewed-By: Tom Tromey <tom@tromey.com>
This commit extends gdbserver to take account of a failed memory
access from agent_mem_read, and to return a new eval_result_type
expr_eval_invalid_memory_access.
I have only updated the agent_mem_read calls related directly to
reading memory, I have not updated any of the calls related to
tracepoint data collection. This is just because I'm not familiar
with that area of gdb/gdbserver, and I don't want to break anything,
so leaving the existing behaviour untouched seems like the safest
approach.
I've then updated gdb.base/bp-cond-failure.exp to test evaluating the
breakpoints on the target, and have also extended the test so that it
checks for different sizes of memory access.
Currently the gdbserver function agent_mem_read ignores any errors
from calling read_inferior_memory. This means that if there is an
attempt to access invalid memory then this will appear to succeed.
In this patch I update agent_mem_read so that if read_inferior_memory
fails, agent_mem_read will return an error code.
However, none of the callers of agent_mem_read actually check the
return value, so this commit will have no effect on anything. In the
next commit I will update the users of agent_mem_read to check for the
error code.
I've also updated the header comments on agent_mem_read to better
reflect what the function does, and its possible return values.
Tom de Vries pointed out that my earlier patch:
commit 873a185be2
Date: Fri Dec 16 07:56:57 2022 -0700
Don't use struct buffer in handle_qxfer_btrace
regressed gdb.btrace/reconnect.exp. I didn't notice this because I
did not have libipt installed.
This patch fixes the bug.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30169
Tested-By: Bruno Larsen <blarsen@redhat.com>
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.
While investigating something else, I noticed some weird code in
agent_run_command (use of memcpy rather than strcpy). Then I noticed
that 'cmd' is used as both an in and out parameter, despite being
const.
Casting away const like this is bad. This patch removes the const and
fixes the memcpy. I also added a static assert to assure myself that
the code in gdbserver is correct -- gdbserver is passing its own
buffer directly to agent_run_command.
Reviewed-By: Andrew Burgess <aburgess@redhat.com>
gdbsupport/errors.h declares perror_with_name and leaves the
implementation to the clients.
However gdb and gdbserver's implementations are essentially the
same, resulting in unnecessary code duplication.
Fix this by implementing perror_with_name in gdbsupport. Add an
optional parameter for specifying the errno used to generate the
error message.
Also move the implementation of perror_string to gdbsupport since
perror_with_name requires it.
Approved-By: Tom Tromey <tom@tromey.com>
This patch doesn't change gdbserver behaviour, but after later changes are
made it avoids a null pointer dereference when HWCAP needs to be obtained
for a specific process while current_thread is nullptr.
Fixing linux_read_auxv, linux_get_hwcap and linux_get_hwcap2 to take a PID
parameter seems more correct than setting current_thread in one particular
code path.
Changes are propagated to allow passing the new parameter through the call
chain.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
It helped me during development, catching bugs closer to when they actually
happened.
Also remove the equivalent gdb_assert in regcache_raw_read_unsigned, since
it's checking the same condition a few frames above.
Suggested-By: Simon Marchi <simon.marchi@efficios.com>
Approved-By: Simon Marchi <simon.marchi@efficios.com>
PR build/29003 points out that "make TAGS" is broken in gdbserver.
This patch fixes the problem that is pointed out there, plus another
one I noticed while working on that -- namely that the "sed" computes
the wrong names for some source files. Finally, a couple of obsolete
variable references are removed.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29003
GCC recently added support for the Windows thread model, enabling
libstdc++ to support Windows natively. However, this supporrt
requires a version of Windows later than the minimum version that is
supported by GDB.
PR build/29966 points out that the GDB configure test for std::thread
does not work in this situation, because _WIN32_WINNT is not defined
in test program, and so <thread> seems to be fine.
This patch is an attempt to fix the problem, by using the same setting
for _WIN32_WINNT at configure time as is used at build time.
I don't have access to one of the older systems so I don't think I can
truly test this. I did do a mingw cross build, though. I'm going to
ask the bug reporter to test it.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29966
The following patch moves the fast_hash function, which uses libxxhash,
to gdbsupport. Move the libxxhash configure check to gdbsupport (and
transitively to gdbserver).
Change-Id: I242499e50c8cd6fe9f51e6e92dc53a1b3daaa96e
Approved-By: Andrew Burgess <aburgess@redhat.com>
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 commit updates the copyright year displayed by gdb, gdbserver
and gdbreplay's help message from 2022 to 2023, as per our Start
of New Year procedure. The corresponding source files' copyright
header are also updated accordingly.
PR gdb/28947
The address_significant gdbarch setting was introduced as a way to remove
non-address bits from pointers, and it is specified by a constant. This
constant represents the number of address bits in a pointer.
Right now AArch64 is the only architecture that uses it, and 56 was a
correct option so far.
But if we are using Pointer Authentication (PAuth), we might use up to 2 bytes
from the address space to store the required information. We could also have
cases where we're using both PAuth and MTE.
We could adjust the constant to 48 to cover those cases, but this doesn't
cover the case where GDB needs to sign-extend kernel addresses after removal
of the non-address bits.
This has worked so far because bit 55 is used to select between kernel-space
and user-space addresses. But trying to clear a range of bits crossing the
bit 55 boundary requires the hook to be smarter.
The following patch renames the gdbarch hook from significant_addr_bit to
remove_non_address_bits and passes a pointer as opposed to the number of
bits. The hook is now responsible for removing the required non-address bits
and sign-extending the address if needed.
While at it, make GDB and GDBServer share some more code for aarch64 and add a
new arch-specific testcase gdb.arch/aarch64-non-address-bits.exp.
Bug-url: https://sourceware.org/bugzilla/show_bug.cgi?id=28947
Approved-By: Simon Marchi <simon.marchi@efficios.com>
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.
New in this version: add a dedicated test.
When I do this:
$ ./gdb -nx --data-directory=data-directory -q \
/bin/sleep \
-ex "maint set target-non-stop on" \
-ex "tar ext :1234" \
-ex "set remote exec-file /bin/sleep" \
-ex "run 1231 &" \
-ex add-inferior \
-ex "inferior 2"
Reading symbols from /bin/sleep...
(No debugging symbols found in /bin/sleep)
Remote debugging using :1234
Starting program: /bin/sleep 1231
Reading /lib64/ld-linux-x86-64.so.2 from remote target...
warning: File transfers from remote targets can be slow. Use "set sysroot" to access files locally instead.
Reading /lib64/ld-linux-x86-64.so.2 from remote target...
Reading /usr/lib/debug/.build-id/a6/7a1408f18db3576757eea210d07ba3fc560dff.debug from remote target...
[New inferior 2]
Added inferior 2 on connection 1 (extended-remote :1234)
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) Reading /lib/x86_64-linux-gnu/libc.so.6 from remote target...
attach 3659848
Attaching to process 3659848
/home/smarchi/src/binutils-gdb/gdb/thread.c:85: internal-error: inferior_thread: Assertion `current_thread_ != nullptr' failed.
Note the "attach" command just above. When doing it on the command-line
with a -ex switch, the bug doesn't trigger.
The internal error of GDB is actually caused by GDBserver crashing, and
the error recovery of GDB is not on point. This patch aims to fix just
the GDBserver crash, not the GDB problem.
GDBserver crashes with a segfault here:
(gdb) bt
#0 0x00005555557fb3f4 in find_one_thread (ptid=...) at /home/smarchi/src/binutils-gdb/gdbserver/thread-db.cc:177
#1 0x00005555557fd5cf in thread_db_thread_handle (ptid=<error reading variable: Cannot access memory at address 0xffffffffffffffa0>, handle=0x7fffffffc400, handle_len=0x7fffffffc3f0)
at /home/smarchi/src/binutils-gdb/gdbserver/thread-db.cc:461
#2 0x000055555578a0b6 in linux_process_target::thread_handle (this=0x5555558a64c0 <the_x86_target>, ptid=<error reading variable: Cannot access memory at address 0xffffffffffffffa0>, handle=0x7fffffffc400,
handle_len=0x7fffffffc3f0) at /home/smarchi/src/binutils-gdb/gdbserver/linux-low.cc:6905
#3 0x00005555556dfcc6 in handle_qxfer_threads_worker (thread=0x60b000000510, buffer=0x7fffffffc8a0) at /home/smarchi/src/binutils-gdb/gdbserver/server.cc:1645
#4 0x00005555556e00e6 in operator() (__closure=0x7fffffffc5e0, thread=0x60b000000510) at /home/smarchi/src/binutils-gdb/gdbserver/server.cc:1696
#5 0x00005555556f54be in for_each_thread<handle_qxfer_threads_proper(buffer*)::<lambda(thread_info*)> >(struct {...}) (func=...) at /home/smarchi/src/binutils-gdb/gdbserver/gdbthread.h:159
#6 0x00005555556e0242 in handle_qxfer_threads_proper (buffer=0x7fffffffc8a0) at /home/smarchi/src/binutils-gdb/gdbserver/server.cc:1694
#7 0x00005555556e04ba in handle_qxfer_threads (annex=0x629000000213 "", readbuf=0x621000019100 '\276' <repeats 200 times>..., writebuf=0x0, offset=0, len=4097)
at /home/smarchi/src/binutils-gdb/gdbserver/server.cc:1732
#8 0x00005555556e1989 in handle_qxfer (own_buf=0x629000000200 "qXfer:threads", packet_len=26, new_packet_len_p=0x7fffffffd630) at /home/smarchi/src/binutils-gdb/gdbserver/server.cc:2045
#9 0x00005555556e720a in handle_query (own_buf=0x629000000200 "qXfer:threads", packet_len=26, new_packet_len_p=0x7fffffffd630) at /home/smarchi/src/binutils-gdb/gdbserver/server.cc:2685
#10 0x00005555556f1a01 in process_serial_event () at /home/smarchi/src/binutils-gdb/gdbserver/server.cc:4176
#11 0x00005555556f4457 in handle_serial_event (err=0, client_data=0x0) at /home/smarchi/src/binutils-gdb/gdbserver/server.cc:4514
#12 0x0000555555820f56 in handle_file_event (file_ptr=0x607000000250, ready_mask=1) at /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:573
#13 0x0000555555821895 in gdb_wait_for_event (block=1) at /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:694
#14 0x000055555581f533 in gdb_do_one_event (mstimeout=-1) at /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:264
#15 0x00005555556ec9fb in start_event_loop () at /home/smarchi/src/binutils-gdb/gdbserver/server.cc:3512
#16 0x00005555556f0769 in captured_main (argc=4, argv=0x7fffffffe0d8) at /home/smarchi/src/binutils-gdb/gdbserver/server.cc:3992
#17 0x00005555556f0e3f in main (argc=4, argv=0x7fffffffe0d8) at /home/smarchi/src/binutils-gdb/gdbserver/server.cc:4078
The reason is a wrong current process when find_one_thread is called.
The current process is the 2nd one, which was just attached. It does
not yet have thread_db data (proc->priv->thread_db is nullptr). As we
iterate on all threads of all process to fulfull the qxfer:threads:read
request, we get to a thread of process 1 for which we haven't read
thread_db information yet (lwp_info::thread_known is false), so we get
into find_one_thread. find_one_thread uses
`current_process ()->priv->thread_db`, assuming the current process
matches the ptid passed as a parameter, which is wrong. A segfault
happens when trying to dereference that thread_db pointer.
Fix this by making find_one_thread not assume what the current process /
current thread is. If it needs to call into libthread_db, which we know
will try to read memory from the current process, then temporarily set
the current process.
In the case where the thread is already know and we return early, we
don't need to switch process.
Add a test to reproduce this specific situation.
Change-Id: I09b00883e8b73b7e5f89d0f47cb4e9c0f3d6caaa
Approved-By: Andrew Burgess <aburgess@redhat.com>
Consider the executable from test-case gdb.base/interrupt-daemon.exp.
When starting it using gdbserver:
...
$ ./build/gdbserver/gdbserver localhost:2345 \
./outputs/gdb.base/interrupt-daemon/interrupt-daemon
...
and connecting to it using gdb:
...
$ gdb -q -ex "target remote localhost:2345" \
-ex "set follow-fork-mode child" \
-ex "break daemon_main" -ex cont
...
we are setup to do the same as in the test-case: interrupt a running inferior
using ^C.
So let's try:
...
(gdb) continue
Continuing.
^C
...
After pressing ^C, nothing happens. This a known problem, filed as
PR remote/18772.
The problem is that in linux_process_target::request_interrupt, a kill is used
to send a SIGINT, but it fails. And it fails silently.
Make the failure verbose by adding a warning, such that the gdbserver output
becomes more helpful:
...
Process interrupt-daemon created; pid = 15068
Listening on port 2345
Remote debugging from host ::1, port 35148
Detaching from process 15068
Detaching from process 15085
gdbserver: Sending SIGINT to process group of pid 15068 failed: \
No such process
...
Note that the failure can easily be reproduced using the test-case and target
board native-gdbserver:
...
(gdb) continue^M
Continuing.^M
PASS: gdb.base/interrupt-daemon.exp: fg: continue
^CFAIL: gdb.base/interrupt-daemon.exp: fg: ctrl-c stops process (timeout)
...
as reported in PR server/23382.
Tested on x86_64-linux.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
Commit 4855cbdc3d ("gdbserver/linux-x86: make is_64bit_tdesc accept
thread as a parameter") caused this when building in 32 bits / i386
mode:
CXX linux-x86-low.o
In file included from /home/smarchi/src/binutils-gdb/gdbserver/linux-x86-low.cc:24:
/home/smarchi/src/binutils-gdb/gdbserver/linux-x86-low.cc: In member function ‘virtual int x86_target::low_get_thread_area(int, CORE_ADDR*)’:
/home/smarchi/src/binutils-gdb/gdbserver/linux-x86-low.cc:357:47: error: ‘lwp’ was not declared in this scope
357 | struct thread_info *thr = get_lwp_thread (lwp);
| ^~~
/home/smarchi/src/binutils-gdb/gdbserver/linux-low.h:709:31: note: in definition of macro ‘get_lwp_thread’
709 | #define get_lwp_thread(lwp) ((lwp)->thread)
| ^~~
This is because it moved the lwp variable declaration inside the
__x86_64__ guard, making it unavailable when building in 32 bits mode.
Move the lwp variable outside of the __x86_64__ region.
Change-Id: I7fa3938c6b44b345c27a52c8b8d3ea12aba53e05
The following patch ("gdbserver: switch to right process in
find_one_thread") makes it so find_one_thread calls into libthread_db
with a current process but no current thread. This tripped on ps_getpid
using current_thread in order to get the process' pid. Get the pid from
`current_process ()` instead, which removes the need to have a current
thread. Eventually, it would be good to get it from the
gdb_ps_prochandle_t structure, to avoid the need for a current process
as well.
Reviewed-By: Andrew Burgess <aburgess@redhat.com>
Change-Id: I9d2fae266419199a2fbc2fde0a5104c6e0dbd2d5
ps_get_thread_area receives as a parameter the lwpid it must work on.
It then calls is_64bit_tdesc, which uses the current_thread as the
thread to work on. However, it is not said that both are the same.
This became a problem when working in a following patch that makes
find_one_thread switch to a process but to no thread (current_thread ==
nullptr). When libthread_db needed to get the thread area,
is_64bit_tdesc would try to get the regcache of a nullptr thread.
Fix that by making is_64bit_tdesc accept the thread to work on as a
parameter. Find the right thread from the context, when possible (when
we know the lwpid to work on). Otherwise, pass "current_thread", to
retain the existing behavior.
Reviewed-By: Andrew Burgess <aburgess@redhat.com>
Change-Id: I44394d6be92392fa28de71982fd04517ce8a3007
Just a small optimization, it's not necessary to recompute lwp at each
iteration.
While at it, change the variable type to long, as ptid_t::lwp returns a
long.
Reviewed-By: Andrew Burgess <aburgess@redhat.com>
Change-Id: I181670ce1f90b59cb09ea4899367750be2ad9105
Gdbserver unconditionally reports support for btrace packets. Do not
report the support, if the underlying target does not say it supports
it. Otherwise GDB would query the server with btrace-related packets
unnecessarily.
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
Introduce a new qXfer:libraries-svr4:read annex key/value pair
lmid=<namespace identifier>
to be used together with start and prev to provide the namespace of start
and prev to gdbserver.
Unknown key/value pairs are ignored by gdbserver so no new supports check
is needed.
Introduce a new library-list-svr4 library attribute
lmid
to provide the namespace of a library entry to GDB.
This implementation uses the address of a namespace's r_debug object as
namespace identifier.
This should have incremented the minor version but since unknown XML
attributes are ignored, anyway, and since changing the version results in
a warning from GDB, the version is left at 1.0.
When listing SVR4 shared libraries, special care has to be taken about the
first library in the default namespace as that refers to the main
executable. The load map address of this main executable is provided in
an attribute of the library-list-svr4 element.
Move that code from where we enumerate libraries inside a single namespace
to where we generate the rest of the library-list-svr4 element. This
allows us to complete the library-list-svr4 element inside one function.
There should be no functional change.
In glibc, the r_debug structure contains (amongst others) the following
fields:
int r_version:
Version number for this protocol. It should be greater than 0.
If r_version is 2, struct r_debug is extended to struct r_debug_extended
with one additional field:
struct r_debug_extended *r_next;
Link to the next r_debug_extended structure. Each r_debug_extended
structure represents a different namespace. The first r_debug_extended
structure is for the default namespace.
1. Change solib_svr4_r_map argument to take the debug base.
2. Add solib_svr4_r_next to find the link map in the next namespace from
the r_next field.
3. Update svr4_current_sos_direct to get the link map in the next namespace
from the r_next field.
4. Don't check shared libraries in other namespaces when updating shared
libraries in a new namespace.
5. Update svr4_same to check the load offset in addition to the name
6. Update svr4_default_sos to also set l_addr_inferior
7. Change the flat solib_list into a per-namespace list using the
namespace's r_debug address to identify the namespace.
Add gdb.base/dlmopen.exp to test this.
To remain backwards compatible with older gdbserver, we reserve the
namespace zero for a flat list of solibs from all namespaces. Subsequent
patches will extend RSP to allow listing libraries grouped by namespace.
This fixes PR 11839.
Co-authored-by: Lu, Hongjiu <hongjiu.lu@intel.com>
In this commit,
commit cf6c1e710e
Date: Mon Jul 11 20:53:48 2022 +0800
gdbserver: remove unused variable
I removed an unused variable in handle_v_run. Pedro then pointed out
that the for loop after it was also unused. After a period of smoke
testing, no exceptions were found.
Tested on x86_64-linux.
I don't see why include/gdb/fileio.h is placed there. It's not
installed by "make install", and it's not included by anything outside
of gdb/gdbserver/gdbsupport.
Move its content back to gdbsupport/fileio.h. I have omitted the bits
inside an `#if 0`, since it's obviously not used, as well as the
"limits" constants, which are also unused.
Change-Id: I6fbc2ea10fbe4cfcf15f9f76006b31b99c20e5a9
Add new files:
gdb/arch/csky.c
gdb/arch/csky.h
gdb/features/cskyv2-linux.c
gdbserver/linux-csky-low.cc
1. In gdb/arch/csky.c file, add function "csky_create_target_description()"
for csky_target::low_arch_setup(). later, it can be used for csky native gdb.
2. In gdb/features/cskyv2-linux.c file, create target_tdesc for csky, include
gprs, pc, hi, lo, float, vector and float control registers.
3. In gdbserver/linux-csky-low.cc file, using PTRACE_GET/SET_RGESET to
get/set registers. The main data structures in asm/ptrace.h are:
struct pt_regs {
unsigned long tls;
unsigned long lr;
unsigned long pc;
unsigned long sr;
unsigned long usp;
/*
* a0, a1, a2, a3:
* r0, r1, r2, r3
*/
unsigned long orig_a0;
unsigned long a0;
unsigned long a1;
unsigned long a2;
unsigned long a3;
/*
* r4 ~ r13
*/
unsigned long regs[10];
/* r16 ~ r30 */
unsigned long exregs[15];
unsigned long rhi;
unsigned long rlo;
unsigned long dcsr;
};
struct user_fp {
unsigned long vr[96];
unsigned long fcr;
unsigned long fesr;
unsigned long fid;
unsigned long reserved;
};
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.
The current implementation of the fcc register is referenced to the
user_fp_state structure of the kernel uapi [1].
struct user_fp_state {
uint64_t fpr[32];
uint64_t fcc;
uint32_t fcsr;
};
But it is mistakenly defined as a 64-bit fputype register, resulting
in a confusing output of "info register".
(gdb) info register
...
fcc {f = 0x0, d = 0x0} {f = 0, d = 0}
...
According to "Condition Flag Register" in "LoongArch Reference Manual"
[2], there are 8 condition flag registers of size 1. Use 8 registers of
uint8 to make it easier for users to view the fcc register groups.
(gdb) info register
...
fcc0 0x1 1
fcc1 0x0 0
fcc2 0x0 0
fcc3 0x0 0
fcc4 0x0 0
fcc5 0x0 0
fcc6 0x0 0
fcc7 0x0 0
...
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/loongarch/include/uapi/asm/ptrace.h
[2] https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#_condition_flag_register
Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
When building with clang 15, I got this error:
CXX server.o
server.cc:2985:10: error: variable 'new_argc' set but not used [-Werror,-Wunused-but-set-variable]
int i, new_argc;
^
Remove the unused variable to eliminate the error.
Tested by rebuilding on x86_64-linux with clang 15.
Commit 736918239b ("gdb: LoongArch: add orig_a0 into register set")
introduced orig_a0, similar processing needs to be done in gdbserver.
At the same time, add orig_a0 related comments.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Move "enum loongarch_regnum" to gdb/arch/loongarch.h so that the
macro definitions can be used in gdbserver/linux-loongarch-low.cc
to simplify the code.
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Simon reported that the recent change to make GDB and GDBserver avoid
reading shell registers caused a GDBserver regression, caught with
ASan while running gdb.server/non-existing-program.exp:
$ /home/smarchi/build/binutils-gdb/gdb/testsuite/../../gdb/../gdbserver/gdbserver stdio non-existing-program
=================================================================
==127719==ERROR: AddressSanitizer: heap-use-after-free on address 0x60f0000000e9 at pc 0x55bcbfa301f4 bp 0x7ffd238a7320 sp 0x7ffd238a7310
WRITE of size 1 at 0x60f0000000e9 thread T0
#0 0x55bcbfa301f3 in scoped_restore_tmpl<bool>::~scoped_restore_tmpl() /home/smarchi/src/binutils-gdb/gdbserver/../gdbsupport/scoped_restore.h:86
#1 0x55bcbfa2ffe9 in post_fork_inferior(int, char const*) /home/smarchi/src/binutils-gdb/gdbserver/fork-child.cc:120
#2 0x55bcbf9c9199 in linux_process_target::create_inferior(char const*, std::__debug::vector<char*, std::allocator<char*> > const&) /home/smarchi/src/binutils-gdb/gdbserver/linux-low.cc:991
#3 0x55bcbf954549 in captured_main /home/smarchi/src/binutils-gdb/gdbserver/server.cc:3941
#4 0x55bcbf9552f0 in main /home/smarchi/src/binutils-gdb/gdbserver/server.cc:4084
#5 0x7ff9d663b0b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x240b2)
#6 0x55bcbf8ef2bd in _start (/home/smarchi/build/binutils-gdb/gdbserver/gdbserver+0x1352bd)
0x60f0000000e9 is located 169 bytes inside of 176-byte region [0x60f000000040,0x60f0000000f0)
freed by thread T0 here:
#0 0x7ff9d6c6f0c7 in operator delete(void*) ../../../../src/libsanitizer/asan/asan_new_delete.cpp:160
#1 0x55bcbf910d00 in remove_process(process_info*) /home/smarchi/src/binutils-gdb/gdbserver/inferiors.cc:164
#2 0x55bcbf9c4ac7 in linux_process_target::remove_linux_process(process_info*) /home/smarchi/src/binutils-gdb/gdbserver/linux-low.cc:454
#3 0x55bcbf9cdaa6 in linux_process_target::mourn(process_info*) /home/smarchi/src/binutils-gdb/gdbserver/linux-low.cc:1599
#4 0x55bcbf988dc4 in target_mourn_inferior(ptid_t) /home/smarchi/src/binutils-gdb/gdbserver/target.cc:205
#5 0x55bcbfa32020 in startup_inferior(process_stratum_target*, int, int, target_waitstatus*, ptid_t*) /home/smarchi/src/binutils-gdb/gdbserver/../gdb/nat/fork-inferior.c:515
#6 0x55bcbfa2fdeb in post_fork_inferior(int, char const*) /home/smarchi/src/binutils-gdb/gdbserver/fork-child.cc:111
#7 0x55bcbf9c9199 in linux_process_target::create_inferior(char const*, std::__debug::vector<char*, std::allocator<char*> > const&) /home/smarchi/src/binutils-gdb/gdbserver/linux-low.cc:991
#8 0x55bcbf954549 in captured_main /home/smarchi/src/binutils-gdb/gdbserver/server.cc:3941
#9 0x55bcbf9552f0 in main /home/smarchi/src/binutils-gdb/gdbserver/server.cc:4084
#10 0x7ff9d663b0b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x240b2)
previously allocated by thread T0 here:
#0 0x7ff9d6c6e5a7 in operator new(unsigned long) ../../../../src/libsanitizer/asan/asan_new_delete.cpp:99
#1 0x55bcbf910ad0 in add_process(int, int) /home/smarchi/src/binutils-gdb/gdbserver/inferiors.cc:144
#2 0x55bcbf9c477d in linux_process_target::add_linux_process_no_mem_file(int, int) /home/smarchi/src/binutils-gdb/gdbserver/linux-low.cc:425
#3 0x55bcbf9c8f4c in linux_process_target::create_inferior(char const*, std::__debug::vector<char*, std::allocator<char*> > const&) /home/smarchi/src/binutils-gdb/gdbserver/linux-low.cc:985
#4 0x55bcbf954549 in captured_main /home/smarchi/src/binutils-gdb/gdbserver/server.cc:3941
#5 0x55bcbf9552f0 in main /home/smarchi/src/binutils-gdb/gdbserver/server.cc:4084
#6 0x7ff9d663b0b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x240b2)
Above we see that in the non-existing-program case, the process gets
deleted before the starting_up flag gets restored to false.
This happens because startup_inferior calls target_mourn_inferior
before throwing an error, and in GDBserver, unlike in GDB, mourning
deletes the process.
Fix this by not using a scoped_restore to manage the starting_up flag,
since we should only clear it when startup_inferior doesn't throw.
Change-Id: I67325d6f81c64de4e89e20e4ec4556f57eac7f6c
For every stop, Linux GDB and GDBserver save the stopped thread's PC,
in lwp->stop_pc. This is done in save_stop_reason, in both
gdb/linux-nat.c and gdbserver/linux-low.cc. However, while we're
going through the shell after "run", in startup_inferior, we shouldn't
be reading registers, as we haven't yet determined the target's
architecture -- the shell's architecture may not even be the same as
the final inferior's.
In gdb/linux-nat.c, lwp->stop_pc is only needed when the thread has
stopped for a breakpoint, and since when going through the shell, no
breakpoint is going to hit, we could simply teach save_stop_reason to
only record the stop pc when the thread stopped for a breakpoint.
However, in gdbserver/linux-low.cc, lwp->stop_pc is used in more cases
than breakpoint hits (e.g., it's used in tracepoints & the
"while-stepping" feature).
So to avoid GDB vs GDBserver divergence, we apply the same approach to
both implementations.
We set a flag in the inferior (process in GDBserver) whenever it is
being nursed through the shell, and when that flag is set,
save_stop_reason bails out early. While going through the shell,
we'll only ever get process exits (normal or signalled), random
signals, and exec events, so nothing is lost.
Change-Id: If0f01831514d3a74d17efd102875de7d2c6401ad
Currently, if GDBserver hits some internal assertion, it exits with
error status, instead of aborting. This makes it harder to debug
GDBserver, as you can't just debug a core file if GDBserver fails an
assertion. I've had to hack the code to make GDBserver abort to debug
something several times before.
I believe the reason it exits instead of aborting, is to prevent
potentially littering the filesystem of smaller embedded targets with
core files. I think I recall Daniel Jacobowitz once saying that many
years ago, but I can't be sure. Anyhow, that seems reasonable to me.
Since we nowadays have a distinction between development and release
modes, I propose to make GDBserver abort on internal error if in
development mode, while keeping the status quo when in release mode.
Thus, after this patch, in development mode, you get:
$ ../gdbserver/gdbserver
../../src/gdbserver/server.cc:3711: A problem internal to GDBserver has been detected.
captured_main: Assertion `0' failed.
Aborted (core dumped)
$
while in release mode, you'll continue to get:
$ ../gdbserver/gdbserver
../../src/gdbserver/server.cc:3711: A problem internal to GDBserver has been detected.
captured_main: Assertion `0' failed.
$ echo $?
1
I do not think that this requires a separate configure switch.
A "--target_board=native-extended-gdbserver" run on Ubuntu 20.04 ends
up with:
=== gdb Summary ===
# of unexpected core files 29
...
for me, of which 8 are GDBserver core dumps, 7 more than without this
patch.
Change-Id: I6861e08ad71f65a0332c91ec95ca001d130b0e9d
Implement LoongArch/Linux support, including XML target description
handling based on features determined, GPR regset support, and software
breakpoint handling.
In the Linux kernel code of LoongArch, ptrace implements PTRACE_POKEUSR
and PTRACE_PEEKUSR in the arch_ptrace function, so srv_linux_usrregs is
set to yes.
With this patch on LoongArch:
$ make check-gdb TESTS="gdb.server/server-connect.exp"
[...]
# of expected passes 18
[...]
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
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.
Replace the sve bool member of aarch64_features with a vq member that
holds the vector quotient. It is zero if SVE is not present.
Add std::hash<> specialization and operator== so that aarch64_features
can be used as a key with std::unordered_map<>.
Change the various functions that create or lookup aarch64 target
descriptions to accept a const aarch64_features object rather than a
growing number of arguments.
Replace the multi-dimension tdesc_aarch64_list arrays used to cache
target descriptions with unordered_maps indexed by aarch64_feature.
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.
Luis noticed that the recent changes to gdbserver to make it track
process and threads independently regressed a few gdb.multi/*.exp
tests for aarch64-linux.
We started seeing the following internal error for
gdb.multi/multi-target-continue.exp for example:
Starting program: binutils-gdb/gdb/testsuite/outputs/gdb.multi/multi-target-continue/multi-target-continue ^M
Error in re-setting breakpoint 2: Remote connection closed^M
../../../repos/binutils-gdb/gdb/thread.c:85: internal-error: inferior_thread: Assertion `current_thread_ != nullptr' failed.^M
A problem internal to GDB has been detected,^M
further debugging may prove unreliable.
A backtrace looks like:
#0 thread_regcache_data (thread=thread@entry=0x0) at ../../../repos/binutils-gdb/gdbserver/inferiors.cc:120
#1 0x0000aaaaaaabf0e8 in get_thread_regcache (thread=0x0, fetch=fetch@entry=0) at ../../../repos/binutils-gdb/gdbserver/regcache.cc:31
#2 0x0000aaaaaaad785c in is_64bit_tdesc () at ../../../repos/binutils-gdb/gdbserver/linux-aarch64-low.cc:194
#3 0x0000aaaaaaad8a48 in aarch64_target::sw_breakpoint_from_kind (this=<optimized out>, kind=4, size=0xffffffffef04) at ../../../repos/binutils-gdb/gdbserver/linux-aarch64-low.cc:3226
#4 0x0000aaaaaaabe220 in bp_size (bp=0xaaaaaab6f3d0) at ../../../repos/binutils-gdb/gdbserver/mem-break.cc:226
#5 check_mem_read (mem_addr=187649984471104, buf=buf@entry=0xaaaaaab625d0 "\006", mem_len=mem_len@entry=56) at ../../../repos/binutils-gdb/gdbserver/mem-break.cc:1862
#6 0x0000aaaaaaacc660 in read_inferior_memory (memaddr=<optimized out>, myaddr=0xaaaaaab625d0 "\006", len=56) at ../../../repos/binutils-gdb/gdbserver/target.cc:93
#7 0x0000aaaaaaac3d9c in gdb_read_memory (len=56, myaddr=0xaaaaaab625d0 "\006", memaddr=187649984471104) at ../../../repos/binutils-gdb/gdbserver/server.cc:1071
#8 gdb_read_memory (memaddr=187649984471104, myaddr=0xaaaaaab625d0 "\006", len=56) at ../../../repos/binutils-gdb/gdbserver/server.cc:1048
#9 0x0000aaaaaaac82a4 in process_serial_event () at ../../../repos/binutils-gdb/gdbserver/server.cc:4307
#10 handle_serial_event (err=<optimized out>, client_data=<optimized out>) at ../../../repos/binutils-gdb/gdbserver/server.cc:4520
#11 0x0000aaaaaaafbcd0 in gdb_wait_for_event (block=block@entry=1) at ../../../repos/binutils-gdb/gdbsupport/event-loop.cc:700
#12 0x0000aaaaaaafc0b0 in gdb_wait_for_event (block=1) at ../../../repos/binutils-gdb/gdbsupport/event-loop.cc:596
#13 gdb_do_one_event () at ../../../repos/binutils-gdb/gdbsupport/event-loop.cc:237
#14 0x0000aaaaaaacacb0 in start_event_loop () at ../../../repos/binutils-gdb/gdbserver/server.cc:3518
#15 captured_main (argc=4, argv=<optimized out>) at ../../../repos/binutils-gdb/gdbserver/server.cc:3998
#16 0x0000aaaaaaab66dc in main (argc=<optimized out>, argv=<optimized out>) at ../../../repos/binutils-gdb/gdbserver/server.cc:4084
This sequence of functions is invoked due to a series of conditions:
1 - The probe-based breakpoint mechanism failed (for some reason) so ...
2 - ... gdbserver has to know what type of architecture it is dealing
with so it can pick the right breakpoint kind, so it wants to
check if we have a 64-bit target.
3 - To determine the size of a register, we currently fetch the
current thread's register cache, and the current thread pointer
is now nullptr.
In #3, the current thread is nullptr because gdb_read_memory clears it
on purpose, via set_desired_process, exactly to expose code relying on
the current thread when it shouldn't. It was always possible to end
up in this situation (when the current thread exits), but it was
harder to reproduce before.
This commit fixes it by tweaking is_64bit_tdesc to look at the current
process's tdesc instead of the current thread's tdesc.
Note that the thread's tdesc is itself filled from the process's
tdesc, so this should be equivalent:
struct regcache *
get_thread_regcache (struct thread_info *thread, int fetch)
{
struct regcache *regcache;
regcache = thread_regcache_data (thread);
...
if (regcache == NULL)
{
struct process_info *proc = get_thread_process (thread);
gdb_assert (proc->tdesc != NULL);
regcache = new_register_cache (proc->tdesc);
set_thread_regcache_data (thread, regcache);
}
...
Change-Id: Ibc809d7345e70a2f058b522bdc5cdbdca97e2cdc
The recent commit 421490af33 ("gdbserver/linux: Access memory even
if threads are running") caused a regression in
gdb.threads/access-mem-running-thread-exit.exp with gdbserver, which I
somehow missed. Like so:
(gdb) print global_var
Cannot access memory at address 0x555555558010
(gdb) FAIL: gdb.threads/access-mem-running-thread-exit.exp: non-stop: access mem (print global_var after writing, inf=2, iter=1)
The problem starts with GDB telling GDBserver to select a thread, via
the Hg packet, which GDBserver complies with, then that thread exits,
and GDB, without knowing the thread is gone, tries to write to memory,
through the context of the previously selected Hg thread.
GDBserver's GDB-facing memory access routines, gdb_read_memory and
gdb_write_memory, call set_desired_thread to make GDBserver re-select
the thread that GDB has selected with the Hg packet. Since the thread
is gone, set_desired_thread returns false, and the memory access
fails.
Now, to access memory, it doesn't really matter which thread is
selected. All we should need is the target process. Even if the
thread that GDB previously selected is gone, and GDB does not yet know
about that exit, it shouldn't matter, GDBserver should still know
which process that thread belonged to.
Fix this by making GDBserver track the current process separately,
like GDB also does. Add a new set_desired_process routine that is
similar to set_desired_thread, but just sets the current process,
leaving the current thread as NULL. Use it in the GDB-facing memory
read and write routines, to avoid failing if the selected thread is
gone, but the process is still around.
Change-Id: I4ff97cb6f42558efbed224b30d5c71f6112d44cd
The recent gnulib import caused a build failure of libinproctrace.so
on PPC:
alloc.c:(.text+0x20): undefined reference to `rpl_malloc'
alloc.c:(.text+0x70): undefined reference to `rpl_realloc'
This patch fixes the problem using the same workaround that was
previously used for free.
I broke the gdbserver build on x86-64 Windows a little while back.
Previously, I could not build this configuration, but today I found
out that if I configure with:
--host=x86_64-w64-mingw32 --target=x86_64-w64-mingw32
using the Fedora 34 tools, it will in fact build. I'm not certain,
but maybe the gnulib update helped with this.
This patch fixes the build. I'm checking it in.
Running
$ ../gdbserver/gdbserver --once --attach :1234 539436
with ASan while /proc/sys/kernel/yama/ptrace_scope is set to 1 (prevents
attaching) shows that we fail to free some platform-specific objects
tied to the process_info (process_info_private and arch_process_info):
Direct leak of 32 byte(s) in 1 object(s) allocated from:
#0 0x7f6b558b3fb9 in __interceptor_calloc /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x562eaf15d04a in xcalloc /home/simark/src/binutils-gdb/gdbserver/../gdb/alloc.c:100
#2 0x562eaf251548 in xcnew<process_info_private> /home/simark/src/binutils-gdb/gdbserver/../gdbsupport/poison.h:122
#3 0x562eaf22810c in linux_process_target::add_linux_process_no_mem_file(int, int) /home/simark/src/binutils-gdb/gdbserver/linux-low.cc:426
#4 0x562eaf22d33f in linux_process_target::attach(unsigned long) /home/simark/src/binutils-gdb/gdbserver/linux-low.cc:1132
#5 0x562eaf1a7222 in attach_inferior /home/simark/src/binutils-gdb/gdbserver/server.cc:308
#6 0x562eaf1c1016 in captured_main /home/simark/src/binutils-gdb/gdbserver/server.cc:3949
#7 0x562eaf1c1d60 in main /home/simark/src/binutils-gdb/gdbserver/server.cc:4084
#8 0x7f6b552f630f in __libc_start_call_main (/usr/lib/libc.so.6+0x2d30f)
Indirect leak of 56 byte(s) in 1 object(s) allocated from:
#0 0x7f6b558b3fb9 in __interceptor_calloc /usr/src/debug/gcc/libsanitizer/asan/asan_malloc_linux.cpp:154
#1 0x562eaf15d04a in xcalloc /home/simark/src/binutils-gdb/gdbserver/../gdb/alloc.c:100
#2 0x562eaf2a0d79 in xcnew<arch_process_info> /home/simark/src/binutils-gdb/gdbserver/../gdbsupport/poison.h:122
#3 0x562eaf295e2c in x86_target::low_new_process() /home/simark/src/binutils-gdb/gdbserver/linux-x86-low.cc:723
#4 0x562eaf22819b in linux_process_target::add_linux_process_no_mem_file(int, int) /home/simark/src/binutils-gdb/gdbserver/linux-low.cc:428
#5 0x562eaf22d33f in linux_process_target::attach(unsigned long) /home/simark/src/binutils-gdb/gdbserver/linux-low.cc:1132
#6 0x562eaf1a7222 in attach_inferior /home/simark/src/binutils-gdb/gdbserver/server.cc:308
#7 0x562eaf1c1016 in captured_main /home/simark/src/binutils-gdb/gdbserver/server.cc:3949
#8 0x562eaf1c1d60 in main /home/simark/src/binutils-gdb/gdbserver/server.cc:4084
#9 0x7f6b552f630f in __libc_start_call_main (/usr/lib/libc.so.6+0x2d30f)
Those objects are deleted by linux_process_target::mourn, but that is
not called if we fail to attach, we only call remove_process. I
initially fixed this by making linux_process_target::attach call
linux_process_target::mourn on failure (before calling error). But this
isn't done anywhere else (including in GDB) so it would just be
confusing to do things differently here.
Instead, add a linux_process_target::remove_linux_process helper method
(which calls remove_process), and call that instead of remove_process in
the Linux target. Move the free-ing of the extra data from the mourn
method to that new method.
Change-Id: I277059a69d5f08087a7f3ef0b8f1792a1fcf7a85
I'm trying to switch these functions to use std::string instead of char
arrays, as much as possible. Some callers benefit from it (can avoid
doing a copy of the result), while others suffer (have to make one more
copy).
Change-Id: Iced49b8ee2f189744c5072a3b217aab5af17a993
Given:
- The prepare_to_access_memory machinery was added for non-stop mode.
- Only Linux supports non-stop.
- Linux no longer needs the prepare_to_access_memory machinery. In
fact, after the previous patch,
linux_process_target::prepare_to_access_memory became a nop.
Thus, prepare_to_access_memory can go away, simplifying core GDBserver
code.
Change-Id: I93ac8bfe66bd61c3d1c4a0e7d419335163120ecf
Similarly to how the native Linux target was changed
and subsequently reworked in these commits:
05c06f318f Linux: Access memory even if threads are running
8a89ddbda2 Avoid /proc/pid/mem races (PR 28065)
... teach GDBserver to access memory even when the current thread is
running, by always accessing memory via /proc/PID/mem.
The existing comment:
/* Neither ptrace nor /proc/PID/mem allow accessing memory through a
running LWP. */
... is incorrect for /proc/PID/mem does allow that.
Actually, from GDB's perspective, GDBserver could already access
memory while threads were running, but at the expense of pausing all
threads for the duration of the memory access, via
prepare_to_access_memory. This new implementation does not require
pausing any thread, thus
linux_process_target::prepare_to_access_memory /
linux_process_target::done_accessing_memory become nops. A subsequent
patch will remove the whole prepare_to_access_memory infrastructure
completely.
The GDBserver linux-low.cc implementation is simpler than GDB's
linux-nat.c's, because GDBserver always adds the unfollowed vfork/fork
children to the process list immediately when the fork/vfork event is
seen out of ptrace. I.e., there's no need to keep the file descriptor
stored on a side map, we can store it directly in the process
structure.
Change-Id: I0abfd782ceaa4ddce8d3e5f3e2dfc5928862ef61
The next patch in this series adds a common helper routine for both
memory reads and writes, like this:
static int
proc_xfer_memory (CORE_ADDR memaddr, unsigned char *readbuf,
const gdb_byte *writebuf, int len)
{
gdb_assert ((readbuf == nullptr) != (writebuf == nullptr));
...
}
int
linux_process_target::read_memory (CORE_ADDR memaddr,
unsigned char *myaddr, int len)
{
return proc_xfer_memory (memaddr, myaddr, nullptr, len);
}
linux_process_target::write_memory (CORE_ADDR memaddr,
const unsigned char *myaddr, int len)
{
return proc_xfer_memory (memaddr, nullptr, myaddr, len);
}
Surprisingly, the assertion fails. That happens because it can happen
that target_write_memory is called with LEN==0, due to this in
gdb/remote.c:
/* Determine whether the remote target supports binary downloading.
This is accomplished by sending a no-op memory write of zero length
to the target at the specified address. (...) */
void
remote_target::check_binary_download (CORE_ADDR addr)
{
...
p = rs->buf.data ();
*p++ = 'X';
p += hexnumstr (p, (ULONGEST) addr);
*p++ = ',';
p += hexnumstr (p, (ULONGEST) 0);
*p++ = ':';
*p = '\0';
In this scenario, in gdbserver's target_write_memory, the "myaddr"
argument of the_target->write_memory is passed the data() of a local
gdb::byte_vector (which is a specialized std::vector). It's valid for
std::vector::data() to return NULL when the vector is empty.
This commit adds an early return to target_write_memory to avoid
target backends having to care about this. For good measure, do the
same on the read side, in read_inferior_memory.
Change-Id: Iac8f04fcf99014c624ef4036bd318ca1771ad491
handle_qxfer_threads_proper needs to pause all threads even if the
target can read memory when threads are running, so use
target_pause_all instead, which is what the Linux implementation of
prepare_to_access_memory uses. (Only Linux implements this hook.)
A following patch will make the Linux backend be able to access memory
when threads are running, and thus will also make
prepare_to_access_memory do nothing, which would cause testsuite
regressions without this change.
Change-Id: I127fec7246b7c45b60dfa7341e781606bf54b5da
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
Currently, gdb's native Windows target implements the exception-based
approach for setting thread names, but gdbserver does not. This patch
moves handle_ms_vc_exception to the shared nat/windows-nat.c code, as
preparation for adding this support to gdbserver.
Currently, the configure check for std::thread relies on pthreads
existing. However, this means that if std::thread is implemented for
a non-pthreads host, then the check will yield the wrong answer. This
happened in AdaCore internal builds. Here, we have this GCC patch:
https://gcc.gnu.org/legacy-ml/gcc-patches/2019-06/msg01840.html
... which adds mingw support to GCC's gthreads implementation, and
also to std::thread.
This configure change fixes this problem and enables threading for
gdb.
The test introduced by the following patch would sometimes fail in this
configuration:
FAIL: gdb.threads/next-fork-other-thread.exp: fork_func=vfork: target-non-stop=on: non-stop=off: displaced-stepping=auto: i=14: next to for loop
The test has multiple threads constantly forking or vforking while the
main thread keep doing "next"s.
(After writing the commit message, I realized this also fixes a similar
failure in gdb.threads/forking-threads-plus-breakpoint.exp with the
native-gdbserver and native-extended-gdbserver boards.)
As stop_all_threads is called, because the main thread finished its
"next", it inevitably happens at some point that we ask the remote
target to stop a thread and wait() reports that this thread stopped with
a fork or vfork event, instead of the SIGSTOP we sent to try to stop it.
While running this test, I attached to GDBserver and stopped at
linux-low.cc:3626. We can see that the status pulled from the kernel
for 2742805 is indeed a vfork event:
(gdb) p/x w
$3 = 0x2057f
(gdb) p WIFSTOPPED(w)
$4 = true
(gdb) p WSTOPSIG(w)
$5 = 5
(gdb) p/x (w >> 8) & (PTRACE_EVENT_VFORK << 8)
$6 = 0x200
However, the statement at line 3626 overrides that:
ourstatus->set_stopped (gdb_signal_from_host (WSTOPSIG (w)));
OURSTATUS becomes "stopped by a SIGTRAP". The information about the
fork or vfork is lost.
It's then all downhill from there, stop_all_threads eventually asks for
a thread list update. That thread list includes the child of that
forgotten fork or vfork, the remote target goes "oh cool, a new process,
let's attach to it!", when in fact that vfork child's destiny was to be
detached.
My reverse-engineered understanding of the code around there is that the
if/else between lines 3562 and 3583 (in the original code) makes sure
OURSTATUS is always initialized (not "ignore"). Either the details are
already in event_child->waitstatus (in the case of fork/vfork, for
example), in which case we just copy event_child->waitstatus to
ourstatus. Or, if the event is a plain "stopped by a signal" or a
syscall event, OURSTATUS is set to "stopped", but without a signal
number. Lines 3601 to 3629 (in the original code) serve to fill in that
last bit of information.
The problem is that when `w` holds the vfork status, the code wrongfully
takes this branch, because WSTOPSIG(w) returns SIGTRAP:
else if (current_thread->last_resume_kind == resume_stop
&& WSTOPSIG (w) != SIGSTOP)
The intent of this branch is, for example, when we sent SIGSTOP to try
to stop a thread, but wait() reports that it stopped with another signal
(that it must have received from somewhere else simultaneously), say
SIGWINCH. In that case, we want to report the SIGWINCH. But in our
fork/vfork case, we don't want to take this branch, as the thread didn't
really stop because it received a signal. For the non "stopped by a
signal" and non "syscall signal" cases, we would ideally skip over all
that snippet that fills in the signal or syscall number.
The fix I propose is to move this snipppet of the else branch of the
if/else above. In addition to moving the code, the last two "else if"
branches:
else if (current_thread->last_resume_kind == resume_stop
&& WSTOPSIG (w) != SIGSTOP)
{
/* A thread that has been requested to stop by GDB with vCont;t,
but, it stopped for other reasons. */
ourstatus->set_stopped (gdb_signal_from_host (WSTOPSIG (w)));
}
else if (ourstatus->kind () == TARGET_WAITKIND_STOPPED)
ourstatus->set_stopped (gdb_signal_from_host (WSTOPSIG (w)));
are changed into a single else:
else
ourstatus->set_stopped (gdb_signal_from_host (WSTOPSIG (w)));
This is the default path we take if:
- W is not a syscall status
- W does not represent a SIGSTOP that have sent to stop the thread and
therefore want to suppress it
Change-Id: If2dc1f0537a549c293f7fa3c53efd00e3e194e79
nat/windows-nat.c has a number of globals that it uses to communicate
with its clients (gdb and gdbserver). However, if we ever want the
Windows ports to be multi-inferior, globals won't work.
This patch takes a step toward that by moving most nat/windows-nat.c
globals into a new struct windows_process_info. Many functions are
converted to be methods on this object.
A couple of globals remain, as they are needed to truly be global due
to the way that the Windows debugging APIs work.
The clients still have a global for the current process. That is,
this patch is a step toward the end goal, but doesn't implement the
goal itself.
I see some failures, at least in gdb.multi/multi-re-run.exp and
gdb.threads/interrupted-hand-call.exp. Running `stress -C $(nproc)` at
the same time as the test makes those tests relatively frequent.
Let's take gdb.multi/multi-re-run.exp as an example. The failure looks
like this, an unexpected "no resumed":
continue
Continuing.
No unwaited-for children left.
(gdb) FAIL: gdb.multi/multi-re-run.exp: re_run_inf=2: iter=1: continue until exit
The situation is:
- Inferior 1 is stopped somewhere, it won't really play a role here.
- Inferior 2 has 2 threads, both stopped.
- We resume inferior 2, the leader thread is expected to exit, making
the process exit.
From GDB's perspective, a failing run looks like this:
[infrun] fetch_inferior_event: enter
[infrun] scoped_disable_commit_resumed: reason=handling event
[infrun] do_target_wait: Found 2 inferiors, starting at #1
[infrun] random_pending_event_thread: None found.
[remote] wait: enter
[remote] Packet received: T0506:20dcffffff7f0000;07:20dcffffff7f0000;10:9551555555550000;thread:pae4cd.ae4cd;core:e;
[remote] wait: exit
[infrun] print_target_wait_results: target_wait (-1.0.0 [process -1], status) =
[infrun] print_target_wait_results: 713933.713933.0 [Thread 713933.713933],
[infrun] print_target_wait_results: status->kind = STOPPED, sig = GDB_SIGNAL_TRAP
[infrun] handle_inferior_event: status->kind = STOPPED, sig = GDB_SIGNAL_TRAP
[infrun] clear_step_over_info: clearing step over info
[infrun] context_switch: Switching context from 0.0.0 to 713933.713933.0
[infrun] handle_signal_stop: stop_pc=0x555555555195
[infrun] start_step_over: enter
[infrun] start_step_over: stealing global queue of threads to step, length = 0
[infrun] operator(): step-over queue now empty
[infrun] start_step_over: exit
[infrun] process_event_stop_test: no stepping, continue
[remote] Sending packet: $Z0,555555555194,1#8e
[remote] Packet received: OK
[infrun] resume_1: step=0, signal=GDB_SIGNAL_0, trap_expected=0, current thread [713933.713933.0] at 0x555555555195
[remote] Sending packet: $QPassSignals:e;10;14;17;1a;1b;1c;21;24;25;2c;4c;97;#0a
[remote] Packet received: OK
[remote] Sending packet: $vCont;c:pae4cd.-1#9f
[infrun] prepare_to_wait: prepare_to_wait
[infrun] reset: reason=handling event
[infrun] maybe_set_commit_resumed_all_targets: enabling commit-resumed for target extended-remote
[infrun] maybe_call_commit_resumed_all_targets: calling commit_resumed for target extended-remote
[infrun] maybe_call_commit_resumed_all_targets: calling commit_resumed for target extended-remote
[infrun] fetch_inferior_event: exit
[infrun] fetch_inferior_event: enter
[infrun] scoped_disable_commit_resumed: reason=handling event
[infrun] do_target_wait: Found 2 inferiors, starting at #0
[infrun] random_pending_event_thread: None found.
[remote] wait: enter
[remote] Packet received: N
[remote] wait: exit
[infrun] print_target_wait_results: target_wait (-1.0.0 [process -1], status) =
[infrun] print_target_wait_results: -1.0.0 [process -1],
[infrun] print_target_wait_results: status->kind = NO_RESUMED
[infrun] handle_inferior_event: status->kind = NO_RESUMED
[remote] Sending packet: $Hgp0.0#ad
[remote] Packet received: OK
[remote] Sending packet: $qXfer:threads:read::0,1000#92
[remote] Packet received: l<threads>\n<thread id="pae4cb.ae4cb" core="3" name="multi-re-run-1" handle="40c7c6f7ff7f0000"/>\n<thread id="pae4cb.ae4cc" core="2" name="multi-re-run-1" handle="40b6c6f7ff7f0000"/>\n<thread id="pae4cd.ae4ce" core="1" name="multi-re-run-2" handle="40b6c6f7ff7f0000"/>\n</threads>\n
[infrun] stop_waiting: stop_waiting
[remote] Sending packet: $qXfer:threads:read::0,1000#92
[remote] Packet received: l<threads>\n<thread id="pae4cb.ae4cb" core="3" name="multi-re-run-1" handle="40c7c6f7ff7f0000"/>\n<thread id="pae4cb.ae4cc" core="2" name="multi-re-run-1" handle="40b6c6f7ff7f0000"/>\n<thread id="pae4cd.ae4ce" core="1" name="multi-re-run-2" handle="40b6c6f7ff7f0000"/>\n</threads>\n
[infrun] infrun_async: enable=0
[infrun] reset: reason=handling event
[infrun] maybe_set_commit_resumed_all_targets: enabling commit-resumed for target extended-remote
[infrun] maybe_call_commit_resumed_all_targets: calling commit_resumed for target extended-remote
[infrun] maybe_call_commit_resumed_all_targets: calling commit_resumed for target extended-remote
[infrun] fetch_inferior_event: exit
We can see that we resume the inferior with vCont;c, but got NO_RESUMED.
When the test passes, we get an EXITED status to indicate the process
has exited.
From GDBserver's point of view, it looks like this. The logs contain
some logging I added and that are part of this patch.
[remote] getpkt: getpkt ("vCont;c:pae4cf.-1"); [no ack sent]
[threads] resume: enter
[threads] thread_needs_step_over: Need step over [LWP 713931]? Ignoring, should remain stopped
[threads] thread_needs_step_over: Need step over [LWP 713932]? Ignoring, should remain stopped
[threads] get_pc: pc is 0x555555555195
[threads] thread_needs_step_over: Need step over [LWP 713935]? No, no breakpoint found at 0x555555555195
[threads] get_pc: pc is 0x7ffff7d35a95
[threads] thread_needs_step_over: Need step over [LWP 713936]? No, no breakpoint found at 0x7ffff7d35a95
[threads] resume: Resuming, no pending status or step over needed
[threads] resume_one_thread: resuming LWP 713935
[threads] proceed_one_lwp: lwp 713935
[threads] resume_one_lwp_throw: continue from pc 0x555555555195
[threads] resume_one_lwp_throw: Resuming lwp 713935 (continue, signal 0, stop not expected)
[threads] resume_one_lwp_throw: NOW ptid=713935.713935.0 stopped=0 resumed=0
[threads] resume_one_thread: resuming LWP 713936
[threads] proceed_one_lwp: lwp 713936
[threads] resume_one_lwp_throw: continue from pc 0x7ffff7d35a95
[threads] resume_one_lwp_throw: Resuming lwp 713936 (continue, signal 0, stop not expected)
[threads] resume_one_lwp_throw: ptrace errno = 3 (No such process)
[threads] resume: exit
[threads] wait_1: enter
[threads] wait_1: [<all threads>]
[threads] wait_for_event_filtered: waitpid(-1, ...) returned 0, ERRNO-OK
[threads] resume_stopped_resumed_lwps: resuming stopped-resumed LWP LWP 713935.713936 at 7ffff7d35a95: step=0
[threads] resume_one_lwp_throw: continue from pc 0x7ffff7d35a95
[threads] resume_one_lwp_throw: Resuming lwp 713936 (continue, signal 0, stop not expected)
[threads] resume_one_lwp_throw: ptrace errno = 3 (No such process)
[threads] operator(): check_zombie_leaders: leader_pid=713931, leader_lp!=NULL=1, num_lwps=2, zombie=0
[threads] operator(): check_zombie_leaders: leader_pid=713935, leader_lp!=NULL=1, num_lwps=2, zombie=1
[threads] operator(): Thread group leader 713935 zombie (it exited, or another thread execd).
[threads] delete_lwp: deleting 713935
[threads] wait_for_event_filtered: exit (no unwaited-for LWP)
sigchld_handler
[threads] wait_1: ret = null_ptid, TARGET_WAITKIND_NO_RESUMED
[threads] wait_1: exit
What happens is:
- We resume the leader (713935) successfully.
- The leader exits.
- We resume the secondary thread (713936), we get ESRCH. This is
expected this the leader has exited.
- resume_one_lwp_throw throws, it's caught by resume_one_lwp.
- resume_one_lwp checks with check_ptrace_stopped_lwp_gone that the
failure can be explained by the LWP becoming zombie, and swallows the
error.
- Note that this means that the secondary lwp still has stopped==1.
- wait_1 is called, probably because linux_process_target::resume marks
the async pipe at the end.
- The exit event isn't ready yet, probably because the machine is under
load, so waitpid returns nothing.
- check_zombie_leaders detects that the leader is zombie and deletes
- We try to find a resumed (non-stopped) LWP to get an event from,
there's none since the leader (that was resumed) is now deleted, and
the secondary thread is still marked stopped.
wait_for_event_filtered returns -1, causing wait_1 to return
NO_RESUMED.
What I notice here is that there is some kind of race between the
availability of the process' exit notification and the call to wait_1
that results from marking the async pipe at the end of resume.
I think what we want from this wait_1 invocation is to keep waiting, as
we will eventually get thread exit notifications for both of our
threads.
The fix I came up with is to mark the secondary thread as !stopped (or
resumed) when we fail to resume it. This makes wait_1 see that there is
at least one resume lwp, so it won't return NO_RESUMED. I think this
makes sense to consider it resumed, because we are going to receive an
exit event for it. Here's the GDBserver logs with the fix applied:
[threads] resume: enter
[threads] thread_needs_step_over: Need step over [LWP 724595]? Ignoring, should remain stopped
[threads] thread_needs_step_over: Need step over [LWP 724596]? Ignoring, should remain stopped
[threads] get_pc: pc is 0x555555555195
[threads] thread_needs_step_over: Need step over [LWP 724597]? No, no breakpoint found at 0x555555555195
[threads] get_pc: pc is 0x7ffff7d35a95
[threads] thread_needs_step_over: Need step over [LWP 724598]? No, no breakpoint found at 0x7ffff7d35a95
[threads] resume: Resuming, no pending status or step over needed
[threads] resume_one_thread: resuming LWP 724597
[threads] proceed_one_lwp: lwp 724597
[threads] resume_one_lwp_throw: continue from pc 0x555555555195
[threads] resume_one_lwp_throw: Resuming lwp 724597 (continue, signal 0, stop not expected)
[threads] resume_one_lwp_throw: NOW ptid=724597.724597.0 stopped=0 resumed=0
[threads] resume_one_thread: resuming LWP 724598
[threads] proceed_one_lwp: lwp 724598
[threads] resume_one_lwp_throw: continue from pc 0x7ffff7d35a95
[threads] resume_one_lwp_throw: Resuming lwp 724598 (continue, signal 0, stop not expected)
[threads] resume_one_lwp_throw: ptrace errno = 3 (No such process)
[threads] resume: exit
[threads] wait_1: enter
[threads] wait_1: [<all threads>]
sigchld_handler
[threads] wait_for_event_filtered: waitpid(-1, ...) returned 0, ERRNO-OK
[threads] operator(): check_zombie_leaders: leader_pid=724595, leader_lp!=NULL=1, num_lwps=2, zombie=0
[threads] operator(): check_zombie_leaders: leader_pid=724597, leader_lp!=NULL=1, num_lwps=2, zombie=1
[threads] operator(): Thread group leader 724597 zombie (it exited, or another thread execd).
[threads] delete_lwp: deleting 724597
[threads] wait_for_event_filtered: sigsuspend'ing
sigchld_handler
[threads] wait_for_event_filtered: waitpid(-1, ...) returned 724598, ERRNO-OK
[threads] wait_for_event_filtered: waitpid 724598 received 0 (exited)
[threads] filter_event: 724598 exited
[threads] wait_for_event_filtered: waitpid(-1, ...) returned 724597, ERRNO-OK
[threads] wait_for_event_filtered: waitpid 724597 received 0 (exited)
[threads] wait_for_event_filtered: waitpid(-1, ...) returned 0, ERRNO-OK
sigchld_handler
[threads] wait_1: ret = LWP 724597.724598, exited with retcode 0
[threads] wait_1: exit
Change-Id: Idf0bdb4cb0313f1b49e4864071650cc83fb3c100
I noticed that both gdbserver and gdb define current_directory.
However, as it is referenced by gdbsupport, it seemed better to define
it there as well. This patch also moves the declaration to
pathstuff.h. Tested by rebuilding.
Move non-Linux-specific support for hardware break/watchpoints from
nat/aarch64-linux-hw-point.c to nat/aarch64-hw-point.c. Changes
beyond a simple split of the code are:
- aarch64_linux_region_ok_for_watchpoint and
aarch64_linux_any_set_debug_regs_state renamed to drop linux_ as
they are not platform specific.
- Platforms must implement the aarch64_notify_debug_reg_change
function which is invoked from the platform-independent code when a
debug register changes for a given debug register state. This does
not use the indirection of a 'low' structure as is done for x86.
- The handling for kernel_supports_any_contiguous_range is not
pristine. For non-Linux it is simply defined to true. Some uses of
this could perhaps be implemented as new 'low' routines for the
various places that check it instead?
- Pass down ptid into aarch64_handle_breakpoint and
aarch64_handle_watchpoint rather than using current_lwp_ptid which
is only defined on Linux. In addition, pass the ptid on to
aarch64_notify_debug_reg_change instead of the unused state
argument.
The previous prepare_resume_reply change missed updating the 'buf'
reference that overwrites the 'T', so if 'buf' was advanced, we'd
still overwrite the wrong character. This fixes it.
Change-Id: Ia8ce433366b85af4e268c1c49e7b447da3130a4d
While playing with adding a new event kind, I noticed that
prepare_resume_reply TARGET_WAITKIND_FORKED, etc. advance 'buf', so if
we force-disable the T packet, we'd fail the *buf == 'T' assertion.
Fix it by tweaking the assertion to always look at the beginning of
the buffer.
Change-Id: I8c38e32353db115edcde418b3b1e8ba12343c22b
Same as the previous patch, but for GDBserver.
In summary, the current zombie leader detection code in linux-low.cc
has a race -- if a multi-threaded inferior exits just before
check_zombie_leaders finds that the leader is now zombie via checking
/proc/PID/status, check_zombie_leaders deletes the leader, assuming we
won't get an event for that exit (which we won't in some scenarios,
but not in this one), which is a false-positive scenario, where the
whole process is simply exiting. Later when we see the last LWP in
our list exit, we report that LWP's exit status as exit code, even
though for the (real) parent process, the exit code that counts is the
child's leader thread's exit code.
Like for GDB, the solution here is to:
- only report whole-process exit events for the leader.
- re-add the leader back to the LWP list when we finally see it
exit.
Change-Id: Id2d7bbb51a415534e1294fff1d555b7ecaa87f1d
This fixes the indentation of
linux_process_target::check_zombie_leaders, which will help with
keeping its comments in sync with the gdb/linux-nat.c counterpart.
Change-Id: I37332343bd80423d934249e3de2d04feefad1891
Reorganize linux-low.cc:linux_process_target::filter_event such that
all the handling for events for LWPs not in the LWP list is together.
This helps make a following patch clearer. The comments and debug
messages have also been tweaked to have them synchronized with the GDB
counterpart.
Change-Id: If9019635f63a846607cfda44b454b4254a404019
Turning on debug output in gdbserver leads to an assertion failure if
gdbserver reports a non-signal event:
[threads] wait_1: LWP 3273770: extended event with waitstatus status->kind = EXECD, execd_pathname = gdb.threads/non-ldr-exc-1/non-ldr-exc-1
[threads] wait_1: Hit a non-gdbserver trap event.
../../src/gdbserver/../gdb/target/waitstatus.h:365: A problem internal to GDBserver has been detected.
sig: Assertion `m_kind == TARGET_WAITKIND_STOPPED || m_kind == TARGET_WAITKIND_SIGNALLED' failed.
Fix it in the obvious way, using target_waitstatus::to_string(),
resulting in, for example:
[threads] wait_1: ret = LWP 1542412.1542412, status->kind = STOPPED, sig = GDB_SIGNAL_TRAP
Change-Id: Ia4832f9b4fa39f4af67fcaf21fd4d909a285a645
On some systems, the gnulib configuration will decide to define open
and/or close as macros to replace the POSIX C functions. This
interferes with using those names in C++ class or namespace scopes.
gdbsupport/
* event-pipe.cc (event_pipe::open): Renamed to ...
(event_pipe::open_pipe): ... this.
(event_pipe::close): Renamed to ...
(event_pipe::close_pipe): ... this.
* event-pipe.h (class event_pipe): Updated.
gdb/
* inf-ptrace.h (async_file_open, async_file_close): Updated.
gdbserver/
* gdbserver/linux-low.cc (linux_process_target::async): Likewise.
The enable_btrace target method takes a ptid_t to identify the thread on
which tracing shall be enabled.
Change this to thread_info * to avoid translating back and forth between
the two. This will be used in a subsequent patch.
Add remote_debug_printf, and use it for all debug messages controlled by
remote_debug.
Change remote_debug to be a bool, which is trivial in this case.
Change-Id: I90de13cb892faec3830047b571661822b126d6e8
Add the threads_debug_printf and THREADS_SCOPED_DEBUG_ENTER_EXIT, which
use the logging infrastructure from gdbsupport/common-debug.h. Replace
all debug_print uses that are predicated by debug_threads with
threads_dethreads_debug_printf. Replace uses of the debug_enter and
debug_exit macros with THREADS_SCOPED_DEBUG_ENTER_EXIT, which serves
essentially the same purpose, but allows showing what comes between the
enter and the exit in an indented form.
Note that "threads" debug is currently used for a bit of everything in
GDBserver, not only threads related stuff. It should ideally be cleaned
up and separated logically as is done in GDB, but that's out of the
scope of this patch.
Change-Id: I2d4546464462cb4c16f7f1168c5cec5a89f2289a
debug_threads is always used as a boolean. Except in ax.cc and
tracepoint.cc. These files have their own macros that use
debug_threads, and have a concept of verbosity level. But they both
have a single level, so it's just a boolean in the end.
Remove this concept of level. If we ever want to re-introduce it, I
think it will be better implemented in a more common location.
Change debug_threads to bool and adjust some users that were treating it
as an int.
Change-Id: I137f596eaf763a08c977dd74417969cedfee9ecf
This commit aims to not make use of -Wmissing-prototypes when
compiling with g++.
Use of -Wmissing-prototypes was added with this commit:
commit a0761e34f0
Date: Wed Mar 11 15:15:12 2020 -0400
gdb: enable -Wmissing-prototypes warning
Because clang can provide helpful warnings with this flag.
Unfortunately, g++ doesn't accept this flag, and will give this
warning:
cc1plus: warning: command line option ‘-Wmissing-prototypes’ is valid for C/ObjC but not for C++
In theory the fact that this flag is not supported should be detected
by the configure check in gdbsupport/warning.m4, but for users of
ccache, this check doesn't work due to a long standing ccache issue:
https://github.com/ccache/ccache/issues/738
The ccache problem is that -W... options are reordered on the command
line, and so -Wmissing-prototypes is seen before -Werror. Usually
this doesn't matter, but the above warning (about the flag not being
valid) is issued before the -Werror flag is processed, and so is not
fatal.
There have been two previous attempts to fix this that I'm aware of.
The first is:
https://sourceware.org/pipermail/gdb-patches/2021-September/182148.html
In this attempt, instead of just relying on a compile to check if a
flag is valid, the proposal was to both compile and link. As linking
doesn't go through ccache, we don't suffer from the argument
reordering problem, and the link phase will correctly fail when using
-Wmissing-prototypes with g++. The configure script will then disable
the use of this flag.
This approach was rejected, and the suggestion was to only add the
-Wmissing-prototypes flag if we are compiling with gcc.
The second attempt, attempts this approach, and can be found here:
https://sourceware.org/pipermail/gdb-patches/2021-November/183076.html
This attempt only adds the -Wmissing-prototypes flag is the value of
GCC is not 'yes'. This feels like it is doing the right thing,
unfortunately, the GCC flag is really a 'is gcc like' flag, not a
strict, is gcc check. As such, GCC is set to 'yes' for clang, which
would mean the flag was not included for clang or gcc. The entire
point of the original commit was to add this flag for clang, so
clearly the second attempt is not sufficient either.
In this new attempt I have added gdbsupport/compiler-type.m4, this
file defines AM_GDB_COMPILER_TYPE. This macro sets the variable
GDB_COMPILER_TYPE to either 'gcc', 'clang', or 'unknown'. In future
the list of values might be extended to cover other compilers, if this
is ever useful.
I've then modified gdbsupport/warning.m4 to only add the problematic
-Wmissing-prototypes flag if GDB_COMPILER_TYPE is not 'gcc'.
I've tested this with both gcc and clang and see the expected results,
gcc no longer attempts to use the -Wmissing-prototypes flag, while
clang continues to use it.
When compiling using ccache, I am no longer seeing the warning.
ax.cc checks CC_HAS_LONG_LONG, but nothing defines this. However,
PRINTF_HAS_LONG_LONG is checked in configure. This patch removes the
former and keeps the latter. This is PR remote/14976 (filed by me in
2012, lol).
I'm checking this in.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=14976
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.
For the avoidance of doubt, all changes in this commits were
performed by the script.
Add the --enable-threading configure option so multithreading can be disabled
at configure time. This is useful for statically-linked builds of
GDB/GDBserver, since the thread library doesn't play well with that setup.
If you try to run a statically-linked GDB built with threading, it will crash
when setting up the number of worker threads.
This new option is also convenient when debugging GDB in a system with lots of
threads, where the thread discovery code in GDB will emit too many messages,
like so:
[New Thread 0xfffff74d3a50 (LWP 2625599)]
If you have X threads, that message will be repeated X times.
The default for --enable-threading is "yes".
If we modify tracepoint.cc to try to use a too long unix socket name,
for example by modifying SOCK_DIR to be:
#define SOCK_DIR "/tmp/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut/salut"
... trying to start an application with libinproctrace.so loaded
crashes:
$ LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libasan.so.6:./libinproctrace.so /bin/ls
/home/smarchi/src/binutils-gdb/gdbserver/../gdbsupport/common-utils.cc:69: A problem internal to GDBserver in-process agent has been detected.
xsnprintf: Assertion `ret < size' failed.
Looking at the rest of the socket initialization code, the intent seems
to be that if something goes wrong, we warn but let the program
execute. So crashing on this failed assertions seems against the intent.
Commit 6cebaf6e1a ("use xsnprintf instead of snprintf.") changed this
code to use xsnprintf instead of snprintf, introducing this assertion.
Before that, snprintf would return a value bigger that UNIX_PATH_MAX and
the "if" after would catch it and emit a warning, which is exactly what
we want. That change was done because LynxOS didn't have snprintf.
Since LynxOS isn't supported anymore, we can simply revert to use
snprintf there.
With this patch, we get a warning (printed by the caller of
gdb_agent_socket_init), but the program keeps executing:
$ LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libasan.so.6:./libinproctrace.so /bin/ls
ipa: could not create sync socket
...
Change-Id: I78bca52d5dc3145335abeae45a42052701e3f5dd
When building gdb with on AArch64 with g++ 11.1.0 (and some preceding
versions too), -O2 and -fsanitize=address, I get this error.
CXX tracepoint-ipa.o
cc1plus: warning: command-line option ‘-Wmissing-prototypes’ is valid for C/ObjC but not for C++
In file included from /usr/include/string.h:519,
from ../gnulib/import/string.h:41,
from /home/simark/src/binutils-gdb/gdbserver/../gdbsupport/common-defs.h:95,
from /home/simark/src/binutils-gdb/gdbserver/server.h:22,
from /home/simark/src/binutils-gdb/gdbserver/tracepoint.cc:19:
In function ‘char* strncpy(char*, const char*, size_t)’,
inlined from ‘int init_named_socket(const char*)’ at /home/simark/src/binutils-gdb/gdbserver/tracepoint.cc:6902:11,
inlined from ‘int gdb_agent_socket_init()’ at /home/simark/src/binutils-gdb/gdbserver/tracepoint.cc:6953:26,
inlined from ‘void* gdb_agent_helper_thread(void*)’ at /home/simark/src/binutils-gdb/gdbserver/tracepoint.cc:7204:41:
/usr/include/bits/string_fortified.h:95:34: error: ‘char* __builtin_strncpy(char*, const char*, long unsigned int)’ output may be truncated copying 107 bytes from a string of length 107 [-Werror=stringop-truncation]
95 | return __builtin___strncpy_chk (__dest, __src, __len,
| ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
96 | __glibc_objsize (__dest));
| ~~~~~~~~~~~~~~~~~~~~~~~~~
Note that _FORTIFY_SOURCE changes the message a bit, but I get a similar
error if I use -D_FORTIFY_SOURCE=0.
I am pretty sure it's spurious and might be related to this GCC bug:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88780
From what I can see, we are copying from a static 108 bytes long buffer
(the global array agent_socket_name) to a 108 bytes long array,
sockaddr_un::sun_path. I don't see anything wrong.
Still, it would make things easier if we didn't see this error. Change
the code to check that the source string length is smaller than the
destination buffer (including space for the NULL byte) and use strcpy.
For anybody who would like to try to reproduce, the full command line
is:
g++ -I. -I/home/simark/src/binutils-gdb/gdbserver -I/home/simark/src/binutils-gdb/gdbserver/../gdb/regformats -I/home/simark/src/binutils-gdb/gdbserver/.. -I/home/simark/src/binutils-gdb/gdbserver/../include -I/home/simark/src/binutils-gdb/gdbserver/../gdb -I/home/simark/src/binutils-gdb/gdbserver/../gnulib/import -I../gnulib/import -I/home/simark/src/binutils-gdb/gdbserver/.. -I.. -pthread -Wall -Wpointer-arith -Wno-unused -Wunused-value -Wunused-variable -Wunused-function -Wno-switch -Wno-char-subscripts -Wempty-body -Wunused-but-set-parameter -Wunused-but-set-variable -Wno-sign-compare -Wno-error=maybe-uninitialized -Wno-mismatched-tags -Wsuggest-override -Wimplicit-fallthrough=3 -Wduplicated-cond -Wshadow=local -Wdeprecated-copy -Wdeprecated-copy-dtor -Wredundant-move -Wmissing-declarations -Wmissing-prototypes -Wstrict-null-sentinel -Wformat -Wformat-nonliteral -Werror -DGDBSERVER -DCONFIG_UST_GDB_INTEGRATION -Drpl_strerror_r=strerror_r -Drpl_free=free -fPIC -DIN_PROCESS_AGENT -fvisibility=hidden -g3 -O2 -fsanitize=address -c -o tracepoint-ipa.o -MT tracepoint-ipa.o -MMD -MP -MF ./.deps/tracepoint-ipa.Tpo /home/simark/src/binutils-gdb/gdbserver/tracepoint.cc
Change-Id: I18e86c0487feead7e7677e69398405e7057cf464
Replace the direct assignments to current_thread with
switch_to_thread. Use scoped_restore_current_thread when appropriate.
There is one instance remaining in linux-low.cc's wait_for_sigstop.
This will be handled in a separate patch.
Regression-tested on X86-64 Linux using the native-gdbserver and
native-extended-gdbserver board files.
Introduce a class for restoring the current thread and a function to
switch to the given thread. This is a preparation for a refactoring
that aims to remove direct assignments to 'current_thread'.
While working with pending fork events, I wondered what would happen if
the user detached an inferior while a thread of that inferior had a
pending fork event. What happens with the fork child, which is
ptrace-attached by the GDB process (or by GDBserver), but not known to
the core? Sure enough, neither the core of GDB or the target detach the
child process, so GDB (or GDBserver) just stays ptrace-attached to the
process. The result is that the fork child process is stuck, while you
would expect it to be detached and run.
Make GDBserver detach of fork children it knows about. That is done in
the generic handle_detach function. Since a process_info already exists
for the child, we can simply call detach_inferior on it.
GDB-side, make the linux-nat and remote targets detach of fork children
known because of pending fork events. These pending fork events can be
stored in:
- thread_info::pending_waitstatus, if the core has consumed the event
but then saved it for later (for example, because it got the event
while stopping all threads, to present an all-stop stop on top of a
non-stop target)
- thread_info::pending_follow: if we ran to a "catch fork" and we
detach at that moment
Additionally, pending fork events can be in target-specific fields:
- For linux-nat, they can be in lwp_info::status and
lwp_info::waitstatus.
- For the remote target, they could be stored as pending stop replies,
saved in `remote_state::notif_state::pending_event`, if not
acknowledged yet, or in `remote_state::stop_reply_queue`, if
acknowledged. I followed the model of remove_new_fork_children for
this: call remote_notif_get_pending_events to process /
acknowledge any unacknowledged notification, then look through
stop_reply_queue.
Update the gdb.threads/pending-fork-event.exp test (and rename it to
gdb.threads/pending-fork-event-detach.exp) to try to detach the process
while it is stopped with a pending fork event. In order to verify that
the fork child process is correctly detached and resumes execution
outside of GDB's control, make that process create a file in the test
output directory, and make the test wait $timeout seconds for that file
to appear (it happens instantly if everything goes well).
This test catches a bug in linux-nat.c, also reported as PR 28512
("waitstatus.h:300: internal-error: gdb_signal target_waitstatus::sig()
const: Assertion `m_kind == TARGET_WAITKIND_STOPPED || m_kind ==
TARGET_WAITKIND_SIGNALLED' failed.). When detaching a thread with a
pending event, get_detach_signal unconditionally fetches the signal
stored in the waitstatus (`tp->pending_waitstatus ().sig ()`). However,
that is only valid if the pending event is of type
TARGET_WAITKIND_STOPPED, and this is now enforced using assertions (iit
would also be valid for TARGET_WAITKIND_SIGNALLED, but that would mean
the thread does not exist anymore, so we wouldn't be detaching it). Add
a condition in get_detach_signal to access the signal number only if the
wait status is of kind TARGET_WAITKIND_STOPPED, and use GDB_SIGNAL_0
instead (since the thread was not stopped with a signal to begin with).
Add another test, gdb.threads/pending-fork-event-ns.exp, specifically to
verify that we consider events in pending stop replies in the remote
target. This test has many threads constantly forking, and we detach
from the program while the program is executing. That gives us some
chance that we detach while a fork stop reply is stored in the remote
target. To verify that we correctly detach all fork children, we ask
the parent to exit by sending it a SIGUSR1 signal and have it write a
file to the filesystem before exiting. Because the parent's main thread
joins the forking threads, and the forking threads wait for their fork
children to exit, if some fork child is not detach by GDB, the parent
will not write the file, and the test will time out. If I remove the
new remote_detach_pid calls in remote.c, the test fails eventually if I
run it in a loop.
There is a known limitation: we don't remove breakpoints from the
children before detaching it. So the children, could hit a trap
instruction after being detached and crash. I know this is wrong, and
it should be fixed, but I would like to handle that later. The current
patch doesn't fix everything, but it's a step in the right direction.
Change-Id: I6d811a56f520e3cb92d5ea563ad38976f92e93dd
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28512
This patch aims at fixing a bug where an inferior is unexpectedly
created when a fork happens at the same time as another event, and that
other event is reported to GDB first (and the fork event stays pending
in GDBserver). This happens for example when we step a thread and
another thread forks at the same time. The bug looks like (if I
reproduce the included test by hand):
(gdb) show detach-on-fork
Whether gdb will detach the child of a fork is on.
(gdb) show follow-fork-mode
Debugger response to a program call of fork or vfork is "parent".
(gdb) si
[New inferior 2]
Reading /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.threads/step-while-fork-in-other-thread/step-while-fork-in-other-thread from remote target...
Reading /home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.threads/step-while-fork-in-other-thread/step-while-fork-in-other-thread from remote target...
Reading symbols from target:/home/simark/build/binutils-gdb/gdb/testsuite/outputs/gdb.threads/step-while-fork-in-other-thread/step-while-fork-in-other-thread...
[New Thread 965190.965190]
[Switching to Thread 965190.965190]
Remote 'g' packet reply is too long (expected 560 bytes, got 816 bytes): ... <long series of bytes>
The sequence of events leading to the problem is:
- We are using the all-stop user-visible mode as well as the
synchronous / all-stop variant of the remote protocol
- We have two threads, thread A that we single-step and thread B that
calls fork at the same time
- GDBserver's linux_process_target::wait pulls the "single step
complete SIGTRAP" and the "fork" events from the kernel. It
arbitrarily choses one event to report, it happens to be the
single-step SIGTRAP. The fork stays pending in the thread_info.
- GDBserver send that SIGTRAP as a stop reply to GDB
- While in stop_all_threads, GDB calls update_thread_list, which ends
up querying the remote thread list using qXfer:threads:read.
- In the reply, GDBserver includes the fork child created as a result
of thread B's fork.
- GDB-side, the remote target sees the new PID, calls
remote_notice_new_inferior, which ends up unexpectedly creating a new
inferior, and things go downhill from there.
The problem here is that as long as GDB did not process the fork event,
it should pretend the fork child does not exist. Ultimately, this event
will be reported, we'll go through follow_fork, and that process will be
detached.
The remote target (GDB-side), has some code to remove from the reported
thread list the threads that are the result of forks not processed by
GDB yet. But that only works for fork events that have made their way
to the remote target (GDB-side), but haven't been consumed by the core
yet, so are still lingering as pending stop replies in the remote target
(see remove_new_fork_children in remote.c). But in our case, the fork
event hasn't made its way to the GDB-side remote target. We need to
implement the same kind of logic GDBserver-side: if there exists a
thread / inferior that is the result of a fork event GDBserver hasn't
reported yet, it should exclude that thread / inferior from the reported
thread list.
This was actually discussed a while ago, but not implemented AFAIK:
https://pi.simark.ca/gdb-patches/1ad9f5a8-d00e-9a26-b0c9-3f4066af5142@redhat.com/#thttps://sourceware.org/pipermail/gdb-patches/2016-June/133906.html
Implementation details-wise, the fix for this is all in GDBserver. The
Linux layer of GDBserver already tracks unreported fork parent / child
relationships using the lwp_info::fork_relative, in order to avoid
wildcard actions resuming fork childs unknown to GDB. This information
needs to be made available to the handle_qxfer_threads_worker function,
so it can filter the reported threads. Add a new thread_pending_parent
target function that allows the Linux target to return the parent of an
eventual fork child.
Testing-wise, the test replicates pretty-much the sequence of events
shown above. The setup of the test makes it such that the main thread
is about to fork. We stepi the other thread, so that the step completes
very quickly, in a single event. Meanwhile, the main thread is resumed,
so very likely has time to call fork. This means that the bug may not
reproduce every time (if the main thread does not have time to call
fork), but it will reproduce more often than not. The test fails
without the fix applied on the native-gdbserver and
native-extended-gdbserver boards.
At some point I suspected that which thread called fork and which thread
did the step influenced the order in which the events were reported, and
therefore the reproducibility of the bug. So I made the test try both
combinations: main thread forks while other thread steps, and vice
versa. I'm not sure this is still necessary, but I left it there
anyway. It doesn't hurt to test a few more combinations.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28288
Change-Id: I2158d5732fc7d7ca06b0eb01f88cf27bf527b990
PR27257 reports a problem that can be reproduced as follows:
- use x86_64 machine with avx512 support
- compile a hello world with -m32 to a.out
- start a gdbserver session with a.out
- use gdb to connect to the gdbserver session
This makes us run into:
...
Listening on port 2346
Remote debugging from host ::1, port 34940
src/gdbserver/regcache.cc:257: \
A problem internal to GDBserver has been detected.
Unknown register zmm16h requested
...
The problem is that i387_xsave_to_cache in gdbserver/i387-fp.cc can't find a
register zmm16h in the register cache.
To understand how this happens, first some background.
SSE has 16 128-bit wide xmm registers.
AVX extends the SSE registers set as follows:
- it extends the 16 existing 128-bit wide xmm registers to 256-bit wide ymm
registers.
AVX512 extends the AVX register set as follows:
- it extends the 16 existing 256-bit wide ymm registers to 512-bit wide zmm
registers.
- it adds 16 additional 512-bit wide zmm registers (with corresponding ymm and
xmm subregisters added as well)
However, in 32-bit mode, there are only 8 xmm/ymm/zmm registers.
The problem we're running into is that gdbserver/i387-fp.cc uses these
constants to describe the size of the register file:
...
static const int num_avx512_zmmh_low_registers = 16;
static const int num_avx512_zmmh_high_registers = 16;
static const int num_avx512_ymmh_registers = 16;
static const int num_avx512_xmm_registers = 16;
...
which are all incorrect for the 32-bit case.
Fix this by replacing the constants with variables that have the appropriate
values in 64-bit and 32-bit mode.
Tested on x86_64-linux with native and unix/-m32.
While working on target_waitstatus changes, I noticed a few places where
const target_waitstatus objects could be passed by reference instead of
by pointers. And in some cases, places where a target_waitstatus could
be passed as const, but was not. Convert them as much as possible.
Change-Id: Ied552d464be5d5b87489913b95f9720a5ad50c5a
Make target_waitstatus_to_string a "to_string" method of
target_waitstatus, a bit like we have ptid_t::to_string already. This
will save a bit of typing.
Change-Id: Id261b7a09fa9fa3c738abac131c191a6f9c13905
PR gdb/28586 points out that "make distclean" fails to delete
config.cache from gdbserver/. This patch fixes the bug, and removes a
duplicate "Makefile" deletion that was also pointed out in the PR.
The rhES5 build failed due to an upstream import a while back. The
bug here is that, while the 'personality' function exists,
ADDR_NO_RANDOMIZE is only defined in <linux/personality.h>, not
<sys/personality.h>.
However, <linux/personality.h> does not declare the 'personality'
function, and <sys/personality.h> and <linux/personality.h> cannot
both be included.
This patch restores one of the removed configure checks and updates
the code to check it.
We had this as a local patch at AdaCore, because it seemed like there
was no interest upstream. However, now it turns out that this fixes
PR build/28555, so I'm sending it now.
I get some diffs when running autoconf in gdbserver, probably leftovers
from commit 5dfe4bfcb9 ("Fix format_pieces selftest on Windows").
Re-generate configure in that directory.
Change-Id: Icdc9906af95fbaf1047a579914b2983f8ec5db08
The current register set selection mechanism for AArch64 is static, based
on a pre-populated array of register sets.
This means that we might potentially probe register sets that are not
available. This is OK if the kernel errors out during ptrace, but probing the
tag_ctl register, for example, does not result in a ptrace error if the kernel
supports the tagged address ABI but not MTE (PR 28355).
Making the register set selection dynamic, based on feature checks, solves
this and simplifies the code a bit. It allows us to list all of the register
sets only once, and pick and choose based on HWCAP/HWCAP2 or other properties.
I plan to backport this fix to GDB 11 as well.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28355
This patch adds gdbserver support for OpenRISC. This has been used for
debugging the glibc port that in being worked on here:
https://github.com/openrisc/or1k-glibc/tree/or1k-port-2
Hence the comment about registers definitions being inline with glibc.
I wanted to write a warning that included two target_pid_to_str calls,
like this:
warning (_("Blabla %s, blabla %s"),
target_pid_to_str (ptid1),
target_pid_to_str (ptid2));
This doesn't work, because target_pid_to_str stores its result in a
static buffer, so my message would show twice the same ptid. Change
target_pid_to_str to return an std::string to avoid this. I don't think
we save much by using a static buffer, but it is more error-prone.
Change-Id: Ie3f649627686b84930529cc5c7c691ccf5d36dc2
This adds some missing code to the 'uninstall' targets in gdb and
gdbserver. It also changes gdb's uninstall target so that it no
longer tries to remove any man page -- this is already done (and more
correctly) by doc/Makefile.in.
I tested this with 'make install' followed by 'make uninstall', then
examining the install tree for regular files. Only the 'dir' file
remains, but this appears to just be how 'install-info' is intended to
work.
This removes a number of unused variables from gdbserver's Makefile.
I found these while working on the subsequent patches, and figured it
would be cleaner to have a separate patch for the deletions.
I stumbled on a bug caused by the fact that a code path read
target_waitstatus::value::sig (expecting it to contain a gdb_signal
value) while target_waitstatus::kind was TARGET_WAITKIND_FORKED. This
meant that the active union field was in fact
target_waitstatus::value::related_pid, and contained a ptid. The read
signal value was therefore garbage, and that caused GDB to crash soon
after. Or, since that GDB was built with ubsan, this nice error
message:
/home/simark/src/binutils-gdb/gdb/linux-nat.c:1271:12: runtime error: load of value 2686365, which is not a valid value for type 'gdb_signal'
Despite being a large-ish change, I think it would be nice to make
target_waitstatus safe against that kind of bug. As already done
elsewhere (e.g. dynamic_prop), validate that the type of value read from
the union matches what is supposed to be the active field.
- Make the kind and value of target_waitstatus private.
- Make the kind initialized to TARGET_WAITKIND_IGNORE on
target_waitstatus construction. This is what most users appear to do
explicitly.
- Add setters, one for each kind. Each setter takes as a parameter the
data associated to that kind, if any. This makes it impossible to
forget to attach the associated data.
- Add getters, one for each associated data type. Each getter
validates that the data type fetched by the user matches the wait
status kind.
- Change "integer" to "exit_status", "related_pid" to "child_ptid",
just because that's more precise terminology.
- Fix all users.
That last point is semi-mechanical. There are a lot of obvious changes,
but some less obvious ones. For example, it's not possible to set the
kind at some point and the associated data later, as some users did.
But in any case, the intent of the code should not change in this patch.
This was tested on x86-64 Linux (unix, native-gdbserver and
native-extended-gdbserver boards). It was built-tested on x86-64
FreeBSD, NetBSD, MinGW and macOS. The rest of the changes to native
files was done as a best effort. If I forgot any place to update in
these files, it should be easy to fix (unless the change happens to
reveal an actual bug).
Change-Id: I0ae967df1ff6e28de78abbe3ac9b4b2ff4ad03b7
Add a constructor to initialize the waitstatus members. Initialize the
others in the class directly.
Change-Id: I10f885eb33adfae86e3c97b1e135335b540d7442
Add a constructor and a destructor. The constructor takes care of the
initialization that happened in add_thread, while the destructor takes
care of the freeing that happened in free_one_thread. This is needed to
make target_waitstatus non-POD, as thread_info contains a member of that
type.
Change-Id: I1db321b4de9dd233ede0d5c101950f1d6f1d13b7
Say we use a gcc version that (while supporting c++11) does not support c++11
by default, and needs an -std setting to enable it.
If gdb would use the default AX_CXX_COMPILE_STDCXX from autoconf-archive, then
we'd have:
...
CXX="g++ -std=gnu++11"
...
That mechanism however has the following problem (quoting from commit
0bcda68539):
...
the top level Makefile passes CXX down to subdirs, and that overrides whatever
gdb/Makefile may set CXX to. The result would be that a make invocation from
the build/gdb/ directory would use "g++ -std=gnu++11" as expected, while a
make invocation at the top level would not.
...
Commit 0bcda68539 fixes this by using a custom AX_CXX_COMPILE_STDCXX which
does:
...
CXX=g++
CXX_DIALECT=-std=gnu++11
...
The problem reported in PR28318 is that using the custom instead of the
default AX_CXX_COMPILE_STDCXX makes the configure test for std::thread
support fail.
We could simply add $CXX_DIALECT to the test for std::thread support, but
that would have to be repeated for each added c++ support test.
Instead, fix this by doing:
...
CXX="g++ -std=gnu++11"
CXX_DIALECT=-std=gnu++11
...
This is somewhat awkward, since it results in -std=gnu++11 occuring twice in
some situations:
...
$ touch src/gdb/dwarf2/read.c
$ ( cd build/gdb; make V=1 dwarf2/read.o )
g++-4.8 -std=gnu++11 -x c++ -std=gnu++11 ...
...
However, both settings are needed:
- the switch in CXX for the std::thread tests (and other tests)
- the switch in CXX_DIALECT so it can be appended in Makefiles, to
counteract the fact that the top-level Makefile overrides CXX
The code added in gdb/ax_cxx_compile_stdcxx.m4 is copied from the default
AX_CXX_COMPILE_STDCXX from autoconf-archive.
Tested on x86_64-linux.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28318
The ptid_t 'tid' member is normally used as an address in gdb -- both
bsd-uthread and ravenscar-thread use it this way. However, because
the type is 'long', this can cause problems with sign extension.
This patch changes the type to ULONGEST to ensure that sign extension
does not occur.
I wanted to find, and potentially modify, all the spots where the
'tid' parameter to the ptid_t constructor was used. So, I temporarily
removed this parameter and then rebuilt.
In order to make it simpler to search through the "real" (nonzero)
uses of this parameter, something I knew I'd have to do multiple
times, I removed any ", 0" from constructor calls.
Co-Authored-By: John Baldwin <jhb@FreeBSD.org>
I noticed that gdbserver/win32-low.h has an unused declaration. This
code was changed a while ago, but this declaration slipped through.
This patch removes it. Tested by rebuilding.
Update gdbserver to check r_version < 1 instead of r_version != 1 so
that r_version can be bumped for a new field in the glibc debugger
interface to support multiple namespaces. Since so far, the gdbserver
only reads fields defined for r_version == 1, it is compatible with
r_version >= 1.
All future glibc debugger interface changes will be backward compatible.
If there is ever the need for backward incompatible change to the glibc
debugger interface, a new DT_XXX element will be provided to access the
new incompatible interface.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=11839
In commit:
commit f069ea46a0
Date: Sat Jul 3 16:29:08 2021 -0700
Rename gdb/ChangeLog to gdb/ChangeLog-2021
The gdb/ChangeLog file was renamed, but all of the other ChangeLog
files relating to gdb were left in place.
As I understand things, the no ChangeLogs policy applies to all the
GDB related directories, so this commit renames all of the remaining
GDB related ChangeLog files.
As with the original commit, the intention behind this commit is to
hopefully stop people merging ChangeLog entries by mistake.
The renames carried out in this commit are:
gdb/doc/ChangeLog -> gdb/doc/ChangeLog-1991-2021
gdb/stubs/ChangeLog -> gdb/stubs/ChangeLog-2012-2020
gdb/testsuite/ChangeLog -> gdb/testsuite/ChangeLog-2014-2021
gdbserver/ChangeLog -> gdbserver/ChangeLog-2002-2021
gdbsupport/ChangeLog -> gdbsupport/ChangeLog-2020-2021
Same idea as the previous patch, but for m_cwd.
To keep things consistent across the board, change get_inferior_cwd as
well, which is shared with GDBserver. So update the related GDBserver
code too.
Change-Id: Ia2c047fda738d45f3d18bc999eb67ceb8400ce4e
The declaration of set_inferior_cwd is currently shared between gdb and
gdbserver, in gdbsupport/common-inferior.h. It doesn't need to be, as
set_inferior_cwd is not called from common code. Only get_inferior_cwd
needs to.
The motivation for this is that a future patch will change the prototype
of set_inferior_cwd in gdb, and I don't want to change it for gdbserver
unnecessarily. I see this as a good cleanup in any case, to reduce to
just the essential what is shared between GDB and GDBserver.
Change-Id: I3127d27d078f0503ebf5ccc6fddf14f212426a73
The next patch will make the use of sigtimedwait conditional to whether
the platform provides it. Start by adding a configure check for it.
gdbsupport/ChangeLog:
* common.m4 (GDB_AC_COMMON): Check for sigtimedwait.
* config.in, configure: Re-generate.
gdb/ChangeLog:
* config.in, configure: Re-generate.
gdbserver/ChangeLog:
* config.in, configure: Re-generate.
Change-Id: Ic7613fe14521b966b4d991bbcd0933ab14629c05
These dirs don't use automake, so use AC_CONFIG_MACRO_DIRS to specify
../config as a search dir for m4 macros. This allows removal of a lot
of hand-written m4_include's from acinclude.m4 files, and simplifies
use of `aclocal` or `autoreconf` as manual -I is not needed.
The current setting assumes that gnulib is only used by dirs
immediately under the source root. Trying to build it two or
more levels deep fails. Switch GNULIB_BUILDDIR to a relative
GNULIB_PARENT_DIR so that it can be used to construct both the
build & source paths.
I wrote a small script to spot a pattern of indentation mistakes I saw
happened in breakpoint.c. And while at it I ran it on all files and
fixed what I found. No behavior changes intended, just indentation and
addition / removal of curly braces.
gdb/ChangeLog:
* Fix some indentation mistakes throughout.
gdbserver/ChangeLog:
* Fix some indentation mistakes throughout.
Change-Id: Ia01990c26c38e83a243d8f33da1d494f16315c6e
Two additional settings for developers who use emacs:
1. Set brace-list-open to 0 for C and C++ modes, this ensures we
format things like:
enum blah
{
....
};
Instead of the default for the emacs GNU style:
enum blah
{
...
};
The former seems to be the GDB style.
2. Set sentence-end-double-space to t. This is actually the default
value for this setting, but if anyone has customised this to nil in
general, then forcing this back to t for GDB files will give a
better behaviour for the paragraph filling.
gdb/ChangeLog:
* .dir-locals.el: Set sentence-end-double-space for all modes, and
set brace-list-open to 0 for C and C++ modes.
gdbserver/ChangeLog:
* .dir-locals.el: Set sentence-end-double-space for all modes, and
set brace-list-open to 0 for C and C++ modes.
gdbsupport/ChangeLog:
* .dir-locals.el: Set sentence-end-double-space for all modes, and
set brace-list-open to 0 for C and C++ modes.
Instead of using a static buffer. This is safer, and we don't really
mind about any extra dynamic allocation here, since it's only used for
debug purposes.
gdb/ChangeLog:
* nat/linux-waitpid.c (status_to_str): Return std::string.
* nat/linux-waitpid.h (status_to_str): Likewise.
* linux-nat.c (linux_nat_post_attach_wait): Adjust.
(linux_nat_target::attach): Adjust.
(linux_handle_extended_wait): Adjust.
(wait_lwp): Adjust.
(stop_wait_callback): Adjust.
(linux_nat_filter_event): Adjust.
(linux_nat_wait_1): Adjust.
* nat/linux-waitpid.c (status_to_str): Adjust.
* nat/linux-waitpid.h (status_to_str): Adjust.
gdbserver/ChangeLog:
* linux-low.cc (linux_process_target::wait_for_event_filtered):
Adjust to status_to_str returning std::string.
Change-Id: Ia8aead70270438a5690f243e6faafff6c38ff757
Currently, in order to tell whether support for disabling address
space randomization on Linux is available, GDB checks if the
personality syscall works, at configure time. I.e., it does a run
test, instead of a compile/link test:
AC_RUN_IFELSE([PERSONALITY_TEST],
[have_personality=true],
[have_personality=false],
This is a bit bogus, because the machine the build is done on may not
(and is when you consider distro gdbs) be the machine that eventually
runs gdb. It would be better if this were a compile/link test
instead, and then at runtime, GDB coped with the personality syscall
failing. Actually, GDB already copes.
One environment where this is problematic is building GDB in a Docker
container -- by default, Docker runs the container with seccomp, with
a profile that disables the personality syscall. You can tell Docker
to use a less restricted seccomp profile, but I think we should just
fix it in GDB.
"man 2 personality" says:
This system call first appeared in Linux 1.1.20 (and thus first
in a stable kernel release with Linux 1.2.0); library support
was added in glibc 2.3.
...
ADDR_NO_RANDOMIZE (since Linux 2.6.12)
With this flag set, disable address-space-layout randomization.
glibc 2.3 was released in 2002.
Linux 2.6.12 was released in 2005.
The original patch that added the configure checks was submitted in
2008. The first version of the patch that was submitted to the list
called personality from common code:
https://sourceware.org/pipermail/gdb-patches/2008-June/058204.html
and then was moved to Linux-specific code:
https://sourceware.org/pipermail/gdb-patches/2008-June/058209.html
Since HAVE_PERSONALITY is only checked in Linux code, and
ADDR_NO_RANDOMIZE exists for over 15 years, I propose just completely
removing the configure checks.
If for some odd reason, some remotely modern system still needs a
configure check, then we can revert this commit but drop the
AC_RUN_IFELSE in favor of always doing the AC_LINK_IFELSE
cross-compile fallback.
gdb/ChangeLog:
* linux-nat.c (linux_nat_target::supports_disable_randomization):
Remove references to HAVE_PERSONALITY.
* nat/linux-personality.c: Remove references to HAVE_PERSONALITY.
(maybe_disable_address_space_randomization)
(~maybe_disable_address_space_randomizatio): Remove references to
HAVE_PERSONALITY.
* config.in, configure: Regenerate.
gdbserver/ChangeLog:
* linux-low.cc:
(linux_process_target::supports_disable_randomization): Remove
reference to HAVE_PERSONALITY.
* config.in, configure: Regenerate.
gdbsupport/ChangeLog:
* common.m4 (personality test): Remove.
Lancelot pointed out that since the refactor at:
https://sourceware.org/pipermail/gdb-patches/2015-January/120503.html
the sys/personality.h include is not needed in linux-low.cc anymore,
as it does not call personality directly itself anymore.
gdbserver/ChangeLog:
* linux-low.cc: Don't include sys/personality.h or define
ADDR_NO_RANDOMIZE.
The 'handle_v_attach', 'handle_v_run', and 'handle_v_kill' functions'
return values are unused. They indicate error/success result by
putting packets. Make the functions void.
Tested by rebuilding.
gdbserver/ChangeLog:
2021-05-06 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* server.cc (handle_v_attach)
(handle_v_run)
(handle_v_kill): Make void.
PR build/27807 points out that my recent changes to the Windows port
missed a spot in win32-i386-low.cc -- a call to
win32_Wow64GetThreadContext remained, causing link errors in
gdbserver. This happened because I tested an i686 build, but this
code is only used on an x86_64 build.
This patch fixes the bug. I am checking it in.
gdbserver/ChangeLog
2021-05-03 Tom Tromey <tromey@adacore.com>
PR build/27807:
* win32-i386-low.cc (i386_get_thread_context): Call
Wow64GetThreadContext, not win32_Wow64GetThreadContext.
This moves the new DLL-loading code into nat/windows-nat.c, and
changes both gdb and gdbserver to use the shared code. One
client-provided callback, handle_load_dll, is changed to allow the
code to be shared. This callback was actually never called from
nat/windows-nat.c; maybe I had planned to share more here and then
didn't finish... I'm not sure.
gdb/ChangeLog
2021-04-30 Tom Tromey <tromey@adacore.com>
* windows-nat.c (windows_nat::handle_load_dll): Update.
(windows_nat_target::get_windows_debug_event): Call
dll_loaded_event.
(windows_add_all_dlls, windows_add_dll): Move to
nat/windows-nat.c.
* nat/windows-nat.h (handle_load_dll): Change parameters.
(dll_loaded_event, windows_add_all_dlls): Declare.
* nat/windows-nat.c (windows_add_dll, windows_add_all_dlls): Move
from windows-nat.c.
(dll_loaded_event): New function.
gdbserver/ChangeLog
2021-04-30 Tom Tromey <tromey@adacore.com>
* win32-low.cc (do_initial_child_stuff): Update.
(windows_nat::handle_load_dll): Rename from win32_add_one_solib.
Change parameter type.
(win32_add_dll, win32_add_all_dlls)
(windows_nat::handle_load_dll): Remove.
(get_child_debug_event): Call dll_loaded_event.
This changes gdbserver to use the function indirection code that was
just moved into nat/windows-nat.[ch]. One additional function is used
by gdbserver that was not used by gdb.
gdb/ChangeLog
2021-04-30 Tom Tromey <tromey@adacore.com>
* nat/windows-nat.h (GenerateConsoleCtrlEvent): New define.
(GenerateConsoleCtrlEvent_ftype, GenerateConsoleCtrlEvent):
Declare.
* nat/windows-nat.c (GenerateConsoleCtrlEvent): Define.
(initialize_loadable): Initialize GenerateConsoleCtrlEvent.
gdbserver/ChangeLog
2021-04-30 Tom Tromey <tromey@adacore.com>
* win32-low.cc (GETPROCADDRESS): Remove.
(winapi_DebugActiveProcessStop, winapi_DebugSetProcessKillOnExit)
(winapi_DebugBreakProcess, winapi_GenerateConsoleCtrlEvent)
(winapi_Wow64SetThreadContext, win32_Wow64GetThreadContext)
(win32_Wow64SetThreadContext): Remove.
(win32_set_thread_context, do_initial_child_stuff)
(win32_process_target::attach, win32_process_target::detach):
Update.
(winapi_EnumProcessModules, winapi_EnumProcessModulesEx)
(winapi_GetModuleInformation, winapi_GetModuleInformationA):
Remove.
(win32_EnumProcessModules, win32_EnumProcessModulesEx)
(win32_GetModuleInformation, win32_GetModuleInformationA):
Remove.
(load_psapi): Remove.
(win32_add_dll, win32_process_target::request_interrupt): Update.
(initialize_low): Call initialize_loadable.
This removes the one last use of _WIN32_WCE from gdbserver.
gdbserver/ChangeLog
2021-04-14 Tom Tromey <tromey@adacore.com>
* win32-low.cc (windows_nat::handle_load_dll): Don't check
_WIN32_WCE.
I noticed that gdbserver/win32-low.cc has a few typedefs that are not
used. This patch removes them.
gdbserver/ChangeLog
2021-04-13 Tom Tromey <tromey@adacore.com>
* win32-low.cc (winapi_CreateToolhelp32Snapshot)
(winapi_Module32First, winapi_Module32Next): Remove typedefs.
The support for WinCE was removed with commit 84b300de36 ("gdbserver:
remove support for ARM/WinCE"). There is some leftover code for WinCE
support, guarded by the _WIN32_WCE macro, which I didn't know of at the
time.
I didn't remove the _WIN32_WCE references in the tests, because in
theory we still support the WinCE architecture in GDB (when debugging
remotely). So someone could run a test with that (although I'd be
really surprised).
gdb/ChangeLog:
* nat/windows-nat.c: Remove all code guarded by _WIN32_WCE.
* nat/windows-nat.h: Likewise.
gdbserver/ChangeLog:
* win32-low.cc: Remove all code guarded by _WIN32_WCE.
* win32-low.h: Likewise.
Change-Id: I7a871b897e2135dc195b10690bff2a01d9fac05a
This fixes win32-low.cc in the same way as a recent change in
windows-nat.c did for GDB: if the lpImageName member of the load-DLL
debug event doesn't allow us to find the file name of the DLL, then
loop over all the DLLs mapped into the inferior to find the one loaded
at the same base address as given by the lpBaseOfDll member of the
debug event.
gdbserver/ChangeLog:
2021-04-11 Eli Zaretskii <eliz@gnu.org>
* win32-low.cc (win32_add_dll): New function, with body almost
identical to what win32_add_all_dlls did. Accepts one argument;
if that is non-NULL, returns the file name of the DLL that is
loaded at the base address equal to that argument, or NULL if not
found. If the argument is NULL, add all the DLLs loaded by the
inferior to the list of solibs and return NULL.
(win32_add_all_dlls): Now a thin wrapper around win32_add_dll.
(windows_nat::handle_load_dll) [!_WIN32_WCE]: If get_image_name
failed to glean the file name of the DLL, call win32_add_dll to
try harder using the lpBaseOfDll member of the load-DLL event.
During reviews, I changed the success/failure variables from int to bool, but
missed updating the code in a couple spots. Given the logic inversion, the
gdbserver code fails instead of succeeding.
Fixed with the following patch. Seems fairly obvious, so I'll push it soon.
gdbserver/ChangeLog:
2021-03-30 Luis Machado <luis.machado@linaro.org>
* server.cc (handle_general_set, handle_query): Update variable
to bool and fix verification logic.
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.
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.
