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2023-05-01gdb: move struct ui and related things to ui.{c,h}Simon Marchi1-1/+1
I'd like to move some things so they become methods on struct ui. But first, I think that struct ui and the related things are big enough to deserve their own file, instead of being scattered through top.{c,h} and event-top.c. Change-Id: I15594269ace61fd76ef80a7b58f51ff3ab6979bc
2023-02-27Convert previous_inferior_ptid to strong reference to thread_infoPedro Alves1-0/+5
I originally wrote this patch, because while working on some other patch, I spotted a regression in the gdb.multi/multi-target-no-resumed.exp.exp testcase. Debugging the issue, I realized that the problem was related to how I was using previous_inferior_ptid to look up the thread the user had last selected. The problem is that previous_inferior_ptid alone doesn't tell you which target that ptid is from, and I was just always using the current target, which was incorrect. Two different targets may have threads with the same ptid. I decided to fix this by replacing previous_inferior_ptid with a strong reference to the thread, called previous_thread. I have since found a new motivation for this change -- I would like to tweak "info program" to not rely on get_last_target_status returning a ptid that still exists in the thread list. With both the follow_fork changes later in this series, and the step-over-thread-exit changes, that can happen, as we'll delete threads and not clear the last waitstatus. A new update_previous_thread function is added that can be used to update previous_thread from inferior_ptid. This must be called in several places that really want to get rid of previous_thread thread, and reset the thread id counter, otherwise we get regressions like these: (gdb) info threads -gid Id GId Target Id Frame - * 1 1 Thread 2974541.2974541 "tids-gid-reset" main () at src/gdb/testsuite/gdb.multi/tids-gid-reset.c:21 - (gdb) PASS: gdb.multi/tids-gid-reset.exp: single-inferior: after restart: info threads -gid + * 1 2 Thread 2958361.2958361 "tids-gid-reset" main () at src/gdb/testsuite/gdb.multi/tids-gid-reset.c:21 + (gdb) FAIL: gdb.multi/tids-gid-reset.exp: single-inferior: after restart: info threads -gid and: Core was generated by `build/gdb/testsuite/outputs/gdb.reverse/sigall-precsave/si'. Program terminated with signal SIGTRAP, Trace/breakpoint trap. #0 gen_ABRT () at src/gdb/testsuite/gdb.reverse/sigall-reverse.c:398 398 kill (getpid (), SIGABRT); +[Current thread is 1 (LWP 2662066)] Restored records from core file build/gdb/testsuite/outputs/gdb.reverse/sigall-precsave/sigall.precsave. #0 gen_ABRT () at src/gdb/testsuite/gdb.reverse/sigall-reverse.c:398 398 kill (getpid (), SIGABRT); continue Continuing. -Program received signal SIGABRT, Aborted. +Thread 1 received signal SIGABRT, Aborted. 0x00007ffff7dfd55b in kill () at ../sysdeps/unix/syscall-template.S:78 78 ../sysdeps/unix/syscall-template.S: No such file or directory. -(gdb) PASS: gdb.reverse/sigall-precsave.exp: sig-test-1: get signal ABRT +(gdb) FAIL: gdb.reverse/sigall-precsave.exp: sig-test-1: get signal ABRT I.e., GDB was failing to restart the thread counter back to 1, because the previous_thread thread was being help due to the strong reference. Tested on GNU/Linux native, gdbserver and gdbserver + "maint set target-non-stop on". gdb/ChangeLog: yyyy-mm-dd Pedro Alves <pedro@palves.net> * infcmd.c (kill_command, detach_command, disconnect_command): Call update_previous_thread. * infrun.c (previous_inferior_ptid): Delete. (previous_thread): New. (update_previous_thread): New. (proceed, init_wait_for_inferior): Call update_previous_thread. (normal_stop): Adjust to compare previous_thread and inferior_thread. Call update_previous_thread. * infrun.h (update_previous_thread): Declare. * target.c (target_pre_inferior, target_preopen): Call update_previous_thread. Change-Id: I42779a1ee51a996fa1e8f6e1525c6605dbfd42c7
2023-02-02gdb: add inferior_pre_detach observableSimon Marchi1-0/+2
Add an observable notified in target_detach just before calling the detach method on the inferior's target stack. This allows observer to do some work on the inferior while it's still ptrace-attached, in the case of a native Linux inferior. Specifically, the amd-dbgapi target will need it in order to call amd_dbgapi_process_detach before the process gets ptrace-detached. Change-Id: I28b6065e251012a4c2db8a600fe13ba31671e3c9 Approved-By: Andrew Burgess <aburgess@redhat.com>
2023-01-01Update copyright year range in header of all files managed by GDBJoel Brobecker1-1/+1
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.
2022-12-16[aarch64] Fix removal of non-address bits for PAuthLuis Machado1-1/+1
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>
2022-12-14gdb: remove the pop_all_targets (and friends) global functionsAndrew Burgess1-39/+1
This commit removes the global functions pop_all_targets, pop_all_targets_above, and pop_all_targets_at_and_above, and makes them methods on the inferior class. As the pop_all_targets functions will unpush each target, which decrements the targets reference count, it is possible that the target might be closed. Right now, closing a target, in some cases, depends on the current inferior being set correctly, that is, to the inferior from which the target was popped. To facilitate this I have used switch_to_inferior_no_thread within the new methods. Previously it was the responsibility of the caller to ensure that the correct inferior was selected. In a couple of places (event-top.c and top.c) I have been able to remove a previous switch_to_inferior_no_thread call. In remote_unpush_target (remote.c) I have left the switch_to_inferior_no_thread call as it is required for the generic_mourn_inferior call.
2022-12-14gdb: remove decref_targetAndrew Burgess1-1/+1
The decref_target function is not really needed. Calling target_ops::decref will just redirect to decref_target anyway, so why not just rename decref_target to target_ops::decref? That's what this commit does. It's not exactly renaming to target_ops::decref, because the decref functionality is handled by a policy class, so the new name is now target_ops_ref_policy::decref. There should be no user visible change after this commit.
2022-12-14gdb: have target_stack automate reference count handlingAndrew Burgess1-19/+24
This commit changes the target_stack class from using a C style array of 'target_ops *' to using a C++ std::array<target_ops_ref, ...>. The benefit of this change is that some of the reference counting of target_ops objects is now done automatically. This commit fixes a crash in gdb.python/py-inferior.exp where GDB crashes at exit, leaving a core file behind. The crash occurs in connpy_connection_dealloc, and is actually triggered by this assert: gdb_assert (conn_obj->target == nullptr); Now a little aside... ... the assert is never actually printed, instead GDB crashes due to calling a pure virtual function. The backtrace at the point of crash looks like this: #7 0x00007fef7e2cf747 in std::terminate() () from /lib64/libstdc++.so.6 #8 0x00007fef7e2d0515 in __cxa_pure_virtual () from /lib64/libstdc++.so.6 #9 0x0000000000de334d in target_stack::find_beneath (this=0x4934d78, t=0x2bda270 <the_dummy_target>) at ../../s> #10 0x0000000000df4380 in inferior::find_target_beneath (this=0x4934b50, t=0x2bda270 <the_dummy_target>) at ../.> #11 0x0000000000de2381 in target_ops::beneath (this=0x2bda270 <the_dummy_target>) at ../../src/gdb/target.c:3047 #12 0x0000000000de68aa in target_ops::supports_terminal_ours (this=0x2bda270 <the_dummy_target>) at ../../src/gd> #13 0x0000000000dde6b9 in target_supports_terminal_ours () at ../../src/gdb/target.c:1112 #14 0x0000000000ee55f1 in internal_vproblem(internal_problem *, const char *, int, const char *, typedef __va_li> Notice in frame #12 we called target_ops::supports_terminal_ours, however, this is the_dummy_target, which is of type dummy_target, and so we should have called dummy_target::supports_terminal_ours. I believe the reason we ended up in the wrong implementation of supports_terminal_ours (which is a virtual function) is because we made the call during GDB's shut-down, and, I suspect, the vtables were in a weird state. Anyway, the point of this patch is not to fix GDB's ability to print an assert during exit, but to address the root cause of the assert. With that aside out of the way, we can return to the main story... Connections are represented in Python with gdb.TargetConnection objects (or its sub-classes). The assert in question confirms that when a gdb.TargetConnection is deallocated, the underlying GDB connection has itself been removed from GDB. If this is not true then we risk creating multiple different gdb.TargetConnection objects for the same connection, which would be bad. To ensure that we have one gdb.TargetConnection object for each connection, the all_connection_objects map exists, this maps the process_stratum_target object (the connection) to the gdb.TargetConnection object that represents the connection. When a connection is removed in GDB the connection_removed observer fires, which we catch with connpy_connection_removed, this function then sets conn_obj->target to nullptr, and removes the corresponding entry from the all_connection_objects map. The first issue here is that connpy_connection_dealloc is being called as part of GDB's exit code, which is run after the Python interpreter has been shut down. The connpy_connection_dealloc function is used to deallocate the gdb.TargetConnection Python object. Surely it is wrong for us to be deallocating Python objects after the interpreter has been shut down. The reason why connpy_connection_dealloc is called during GDB's exit is that the global all_connection_objects map is still holding a reference to the gdb.TargetConnection object. When the map is destroyed during GDB's exit, the gdb.TargetConnection objects within the map can finally be deallocated. The reason why all_connection_objects has contents when GDB exits, and the reason the assert fires, is that, when GDB exits, there are still some connections that have not yet been removed from GDB, that is, they have a non-zero reference count. If we take a look at quit_force (top.c) you can see that, for each inferior, we call pop_all_targets before we (later in the function) call do_final_cleanups. It is the do_final_cleanups call that is responsible for shutting down the Python interpreter. The pop_all_targets calls should, in theory, cause all the connections to be removed from GDB. That this isn't working indicates that some targets have a non-zero reference count even after this final pop_all_targets call, and indeed, when I debug GDB, that is what I see. I tracked the problem down to delete_inferior where we do some house keeping, and then delete the inferior object, which calls inferior::~inferior. In neither delete_inferior or inferior::~inferior do we call pop_all_targets, and it is this missing call that means we leak some references to the target_ops objects on the inferior's target_stack. In this commit I will provide a partial fix for the problem. I say partial fix, but this will actually be enough to resolve the crash. In a later commit I will provide the final part of the fix. As mentioned at the start of the commit message, this commit changes the m_stack in target_stack to hold target_ops_ref objects. This means that when inferior::~inferior is called, and m_stack is released, we automatically decrement the target_ops reference count. With this change in place we no longer leak any references, and now, in quit_force the final pop_all_targets calls will release the final references. This means that the targets will be correctly closed at this point, which means the connections will be removed from GDB and the Python objects deallocated before the Python interpreter shuts down. There's a slight oddity in target_stack::unpush, where we std::move the reference out of m_stack like this: auto ref = std::move (m_stack[stratum]); the `ref' isn't used explicitly, but it serves to hold the target_ops_ref until the end of the scope while allowing the m_stack entry to be reset back to nullptr. The alternative would be to directly set the m_stack entry to nullptr, like this: m_stack[stratum] = nullptr; The problem here is that when we set the m_stack entry to nullptr we first decrement the target_ops reference count, and then set the array entry to nullptr. If the decrement means that the target_ops object reaches a zero reference count then the target_ops object will be closed by calling target_close. In target_close we ensure that the target being closed is not in any inferiors target_stack. As we decrement before clearing, then this check in target_close will fail, and an assert will trigger. By using std::move to move the reference out of m_stack, this clears the m_stack entry, meaning the inferior no longer contains the target_ops in its target_stack. Now when the REF object goes out of scope and the reference count is decremented, target_close can run successfully. I've made use of the Python connection_removed listener API to add a test for this issue. The test installs a listener and then causes delete_inferior to be called, we can then see that the connection is then correctly removed (because the listener triggers).
2022-11-28gdb: disable commit resumed in target_killSimon Marchi1-0/+9
New in this version: - Better comment in target_kill - Uncomment line in test to avoid hanging when exiting, when testing on native-extended-gdbserver PR 28275 shows that doing a sequence of: - Run inferior in background (run &) - kill that inferior - Run again We get into this assertion: /home/smarchi/src/binutils-gdb/gdb/target.c:2590: internal-error: target_wait: Assertion `!proc_target->commit_resumed_state' failed. #0 internal_error_loc (file=0x5606b344e740 "/home/smarchi/src/binutils-gdb/gdb/target.c", line=2590, fmt=0x5606b344d6a0 "%s: Assertion `%s' failed.") at /home/smarchi/src/binutils-gdb/gdbsupport/errors.cc:54 #1 0x00005606b6296475 in target_wait (ptid=..., status=0x7fffb9390630, options=...) at /home/smarchi/src/binutils-gdb/gdb/target.c:2590 #2 0x00005606b5767a98 in startup_inferior (proc_target=0x5606bfccb2a0 <the_amd64_linux_nat_target>, pid=3884857, ntraps=1, last_waitstatus=0x0, last_ptid=0x0) at /home/smarchi/src/binutils-gdb/gdb/nat/fork-inferior.c:482 #3 0x00005606b4e6c9c5 in gdb_startup_inferior (pid=3884857, num_traps=1) at /home/smarchi/src/binutils-gdb/gdb/fork-child.c:132 #4 0x00005606b50f14a5 in inf_ptrace_target::create_inferior (this=0x5606bfccb2a0 <the_amd64_linux_nat_target>, exec_file=0x604000039f50 "/home/smarchi/build/binutils-gdb/gdb/test", allargs="", env=0x61500000a580, from_tty=1) at /home/smarchi/src/binutils-gdb/gdb/inf-ptrace.c:105 #5 0x00005606b53b6d23 in linux_nat_target::create_inferior (this=0x5606bfccb2a0 <the_amd64_linux_nat_target>, exec_file=0x604000039f50 "/home/smarchi/build/binutils-gdb/gdb/test", allargs="", env=0x61500000a580, from_tty=1) at /home/smarchi/src/binutils-gdb/gdb/linux-nat.c:978 #6 0x00005606b512b79b in run_command_1 (args=0x0, from_tty=1, run_how=RUN_NORMAL) at /home/smarchi/src/binutils-gdb/gdb/infcmd.c:468 #7 0x00005606b512c236 in run_command (args=0x0, from_tty=1) at /home/smarchi/src/binutils-gdb/gdb/infcmd.c:526 When running the kill command, commit_resumed_state for the process_stratum_target (linux-nat, here) is true. After the kill, when there are no more threads, commit_resumed_state is still true, as nothing touches this flag during the kill operation. During the subsequent run command, run_command_1 does: scoped_disable_commit_resumed disable_commit_resumed ("running"); We would think that this would clear the commit_resumed_state flag of our native target, but that's not the case, because scoped_disable_commit_resumed iterates on non-exited inferiors in order to find active process targets. And after the kill, the inferior is exited, and the native target was unpushed from it anyway. So scoped_disable_commit_resumed doesn't touch the commit_resumed_state flag of the native target, it stays true. When reaching target_wait, in startup_inferior (to consume the initial expect stop events while the inferior is starting up and working its way through the shell), commit_resumed_state is true, breaking the contract saying that commit_resumed_state is always false when calling the targets' wait method. (note: to be correct, I think that startup_inferior should toggle commit_resumed between the target_wait and target_resume calls, but I'll ignore that for now) I can see multiple ways to fix this. In the end, we need commit_resumed_state to be cleared by the time we get to that target_wait. It could be done at the end of the kill command, or at the beginning of the run command. To keep things in a coherent state, I'd like to make it so that after the kill command, when the target is left with no threads, its commit_resumed_state flag is left to false. This way, we can keep working with the assumption that a target with no threads (and therefore no running threads) has commit_resumed_state == false. Do this by adding a scoped_disable_commit_resumed in target_kill. It clears the target's commit_resumed_state on entry, and leaves it false if the target does not have any resumed thread on exit. That means, even if the target has another inferior with stopped threads, commit_resumed_state will be left to false, which makes sense. Add a test that tries to cover various combinations of actions done while an inferior is running (and therefore while commit_resumed_state is true on the process target). Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28275 Change-Id: I8e6fe6dc1f475055921520e58cab68024039a1e9 Approved-By: Andrew Burgess <aburgess@redhat.com>
2022-11-28gdb: fix assert when quitting GDB while a thread is steppingAndrew Burgess1-0/+5
This commit addresses one of the issues identified in PR gdb/28275. Bug gdb/28275 identifies a number of situations in which this assert: Assertion `!proc_target->commit_resumed_state' failed. could be triggered. There's actually a number of similar places where this assert is found in GDB, the two of interest in gdb/28275 are in target_wait and target_stop. In one of the comments: https://sourceware.org/bugzilla/show_bug.cgi?id=28275#c1 steps to trigger the assertion within target_stop were identified when using a modified version of the gdb.threads/detach-step-over.exp test script. In the gdb.threads/detach-step-over.exp test, we attach to a multi-threaded inferior, and continue the inferior in asynchronous (background) mode. Each thread is continuously hitting a conditional breakpoint where the condition is always false. While the inferior is running we detach. The goal is that we detach while GDB is performing a step-over for the conditional breakpoint in at least one thread. While detaching, if a step-over is in progress, then GDB has to complete the step over before we can detach. This involves calling target_stop and target_wait (see prepare_for_detach). As far as gdb/28275 is concerned, the interesting part here, is the the process_stratum_target::commit_resumed_state variable must be false when target_stop and target_wait are called. This is currently ensured because, in detach_command (infrun.c), we create an instance of scoped_disable_commit_resumed, this ensures that when target_detach is called, ::commit_resumed_state will be false. The modification to the test that I propose here, and which exposed the bug, is that, instead of using "detach" to detach from the inferior, we instead use "quit". Quitting GDB after attaching to an inferior will cause GDB to first detach, and then exit. When we quit GDB we end up calling target_detach via a different code path, the stack looks like: #0 target_detach #1 kill_or_detach #2 quit_force #3 quit_command Along this path there is no scoped_disable_commit_resumed created. ::commit_resumed_state can be true when we reach prepare_for_detach, which calls target_wait and target_stop, so the assertion will trigger. In this commit, I propose fixing this by adding the creation of a scoped_disable_commit_resumed into target_detach. This will ensure that ::commit_resumed_state is false when calling prepare_for_detach from within target_detach. I did consider placing the scoped_disable_commit_resumed in prepare_for_detach, however, placing it in target_detach ensures that the target's commit_resumed_state flag is left to false if the detached inferior was the last one for that target. It's the same rationale as for patch "gdb: disable commit resumed in target_kill" that comes later in this series, but for detach instead of kill. detach_command still includes a scoped_disable_commit_resumed too, but I think it is still relevant to cover the resumption at the end of the function. Co-Authored-By: Simon Marchi <simon.marchi@efficios.com> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28275 Change-Id: Ie128f7aba6ef0e018859275eca372e6ea738e96f
2022-11-27Use false/true for some inferior class members instead of 0/1Philippe Waroquiers1-1/+1
Some class members were changed to bool, but there was still some assignments or comparisons using 0/1. Approved-By: Simon Marchi <simon.marchi@efficios.com>
2022-10-19internal_error: remove need to pass __FILE__/__LINE__Pedro Alves1-13/+7
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
2022-09-21gdbsupport: convert FILEIO_* macros to an enumSimon Marchi1-23/+23
Converting from free-form macros to an enum gives a bit of type-safety. This caught places where we would assign host error numbers to what should contain a target fileio error number, for instance in target_fileio_pread. I added the FILEIO_SUCCESS enumerator, because remote.c:remote_hostio_parse_result initializes the remote_errno output variable to 0. It seems better to have an explicit enumerator than to assign a value for which there is no enumerator. I considered initializing this variable to FILEIO_EUNKNOWN instead, such that if the remote side replies with an error and omits the errno value, we'll get an errno that represents an error instead of 0 (which reprensents no error). But it's not clear what the consequences of that change would be, so I prefer to err on the side of caution and just keep the existing behavior (there is no intended change in behavior with this patch). Note that remote_hostio_parse_resul still reads blindly what the remote side sends as a target errno into this variable, so we can still end up with a nonsensical value here. It's not good, but out of the scope of this patch. Convert host_to_fileio_error and fileio_errno_to_host to return / accept a fileio_error instead of an int, and cascade the change in the whole chain that uses that. Change-Id: I454b0e3fcf0732447bc872252fa8e57d138b0e03
2022-09-21gdbsupport: move include/gdb/fileio.h contents to fileio.hSimon Marchi1-1/+1
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
2022-07-22Change target_ops::async to accept boolTom Tromey1-2/+2
This changes the parameter of target_ops::async from int to bool. Regression tested on x86-64 Fedora 34.
2022-05-13Constify target_pid_to_exec_fileTom Tromey1-1/+1
This changes target_pid_to_exec_file and target_ops::pid_to_exec_file to return a "const char *". I couldn't build many of these targets, but did examine the code by hand -- also, as this only affects the return type, it's normally pretty safe. This brings gdb and gdbserver a bit closer, and allows for the removal of a const_cast as well.
2022-04-29Slightly tweak and clarify target_resume's interfacePedro Alves1-5/+8
The current target_resume interface is a bit odd & non-intuitive. I've found myself explaining it a couple times the recent past, while reviewing patches that assumed STEP/SIGNAL always applied to the passed in PTID. It goes like this today: - if the passed in PTID is a thread, then the step/signal request is for that thread. - otherwise, if PTID is a wildcard (all threads or all threads of process), the step/signal request is for inferior_ptid, and PTID indicates which set of threads run free. Because GDB always switches the current thread to "leader" thread being resumed/stepped/signalled, we can simplify this a bit to: - step/signal are always for inferior_ptid. - PTID indicates the set of threads that run free. Still not ideal, but it's a minimal change and at least there are no special cases this way. That's what this patch does. It renames the PTID parameter to SCOPE_PTID, adds some assertions to target_resume, and tweaks target_resume's description. In addition, it also renames PTID to SCOPE_PTID in the remote and linux-nat targets, and simplifies their implementation a little bit. Other targets could do the same, but they don't have to. Change-Id: I02a2ec2ab3a3e9b191de1e9a84f55c17cab7daaf
2022-04-14Move target_read_string to target/target.cTom Tromey1-19/+0
This moves the two overloads of target_read_string to a new file, target/target.c, and updates both gdb and gdbserver to build this.
2022-04-14Remove the byte order parameter to target_read_stringTom Tromey1-2/+1
target_read_string takes a byte order parameter, but only uses this to check whether a given character is zero. This is readily done without requiring the parameter, so remove it.
2022-04-14Rename read_stringTom Tromey1-2/+2
This renames read_string to be an overload of target_read_string. This makes it more consistent for the eventual merger with gdbserver.
2022-04-04Handle TLS variable lookups when using separate debug files.John Baldwin1-0/+5
Commit df22c1e5d53c38f38bce6072bb46de240f9e0e2b handled the case that a separate debug file was passed as the objfile for a shared library to svr4_fetch_objfile_link_map. However, a separate debug file can also be passed for TLS variables in the main executable. In addition, frv_fetch_objfile_link_map also expects to be passed the original objfile rather than a separate debug file, so pull the code to resolve a separate debug file to the main objfile up into target_translate_tls_address.
2022-03-29Unify gdb printf functionsTom Tromey1-92/+92
Now that filtered and unfiltered output can be treated identically, we can unify the printf family of functions. This is done under the name "gdb_printf". Most of this patch was written by script.
2022-03-29Unify gdb putc functionsTom Tromey1-1/+1
Now that filtered and unfiltered output can be treated identically, we can unify the putc family of functions. This is done under the name "gdb_putc". Most of this patch was written by script.
2022-03-29Unify gdb puts functionsTom Tromey1-1/+1
Now that filtered and unfiltered output can be treated identically, we can unify the puts family of functions. This is done under the name "gdb_puts". Most of this patch was written by script.
2022-03-29Remove some uses of printf_unfilteredTom Tromey1-8/+8
A number of spots call printf_unfiltered only because they are in code that should not be interrupted by the pager. However, I believe these cases are all handled by infrun's blanket ban on paging, and so can be converted to the default (_filtered) API. After this patch, I think all the remaining _unfiltered calls are ones that really ought to be. A few -- namely in complete_command -- could be replaced by a scoped assignment to pagination_enabled, but for the remainder, the code seems simple enough like this.
2022-03-14Replace deprecated_target_wait_hook by observersPatrick Monnerat1-1/+13
Commit b60cea7 (Make target_wait options use enum flags) broke deprecated_target_wait_hook usage: there's a commit comment telling this hook has not been converted. Rather than trying to mend it, this patch replaces the hook by two target_wait observers: target_pre_wait (ptid_t ptid) target_post_wait (ptid_t event_ptid) Upon target_wait entry, target_pre_wait is notified with the ptid passed to target_wait. Upon exit, target_post_wait is notified with the event ptid returned by target_wait. Should an exception occur, event_ptid is null_ptid. This change benefits to Insight (out-of-tree): there's no real use of the late hook in gdb itself.
2022-02-22Enable async mode on supported targets in target_resume.John Baldwin1-0/+3
Enabling async mode above the target layer removes duplicate code in ::resume methods of async-capable targets. Commit 5b6d1e4fa4f ("Multi-target support") enabled async mode in do_target_resume after target_resume returns which is a step in this direction. However, other callers of target_resume such as target_continue do not enable async mode. Rather than enabling async mode in each of the callers after target_resume returns, enable async mode at the end of target_resume.
2022-01-27gdb, gdbserver: update thread identifier in enable_btrace target methodMarkus Metzger1-2/+2
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.
2022-01-26gdb: convert maintenance target-async and target-non-stop settings to callbacksSimon Marchi1-36/+32
This simplifies things a bit, as we don't need two variables and think about reverting target_async_permitted_1 and target_non_stop_enabled_1 values if we can't change the setting. Change-Id: I36acab045dacf02ae1988486cfdb27c1dff309f6
2022-01-08Add explicit check for nullptr to target_announce_attachTom Tromey1-1/+1
Lancelot pointed out that target_announce_attach was missing an explicit check against nullptr. This patch adds it.
2022-01-06Use target_announce_detach in more targetsTom Tromey1-6/+7
target_announce_detach was added in commit 0f48b757 ("Factor out "Detaching from program" message printing"). There, Pedro wrote: (For now, I left the couple targets that print this a bit differently alone. Maybe this could be further pulled out into infcmd.c. If we did that, and those targets want to continue printing differently, this new function could be converted to a target method.) It seems to me that the differences aren't very big, and in some cases other targets handled the output a bit more nicely. In particular, some targets will print a different message when exec_file==NULL, rather than printing the same output with an empty string as exec_file. This patch incorporates the nicer output into target_announce_detach, then changes the remaining ports to use this function.
2022-01-06Introduce target_announce_attachTom Tromey1-0/+18
This introduces target_announce_attach, by analog with target_announce_detach. Then it converts existing targets to use this, rather than emitting their own output by hand.
2022-01-05Use filtered output in terminal_info implementationsTom Tromey1-1/+1
This changes one terminal_info implementation, and default_terminal_info, to use filtered output. Other implementations of this method already use filtered output. I can't compile go32-nat.c, so this is a 'best effort' patch.
2022-01-05Use filtered output in files_info implementationsTom Tromey1-5/+5
This changes the implementations of the target files_info method to use filtered output. This makes sense because the sole caller of this method is an ordinary command (info_program_command). This patch changes this command to use filtered output as well.
2022-01-01Automatic Copyright Year update after running gdb/copyright.pyJoel Brobecker1-1/+1
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.
2021-12-13gdb: make post_startup_inferior a virtual method on inf_ptrace_targetAndrew Burgess1-8/+0
While working on a later patch that required me to understand how GDB starts up inferiors, I was confused by the target_ops::post_startup_inferior method. The post_startup_inferior target function is only called from inf_ptrace_target::create_inferior. Part of the target class hierarchy looks like this: inf_child_target | '-- inf_ptrace_target | |-- linux_nat_target | |-- fbsd_nat_target | |-- nbsd_nat_target | |-- obsd_nat_target | '-- rs6000_nat_target Every sub-class of inf_ptrace_target, except rs6000_nat_target, implements ::post_startup_inferior. The rs6000_nat_target picks up the implementation of ::post_startup_inferior not from inf_ptrace_target, but from inf_child_target. No descendent of inf_child_target, outside the inf_ptrace_target sub-tree, implements ::post_startup_inferior, which isn't really surprising, as they would never see the method called (remember, the method is only called from inf_ptrace_target::create_inferior). What I find confusing is the role inf_child_target plays in implementing, what is really a helper function for just one of its descendents. In this commit I propose that we formally make ::post_startup_inferior a helper function of inf_ptrace_target. To do this I will remove the ::post_startup_inferior from the target_ops API, and instead make this a protected, pure virtual function on inf_ptrace_target. I'll remove the empty implementation of ::post_startup_inferior from the inf_child_target class, and add a new empty implementation to the rs6000_nat_target class. All the other descendents of inf_ptrace_target already provide an implementation of this method and so don't need to change beyond making the method protected within their class declarations. To me, this makes much more sense now. The helper function, which is only called from within the inf_ptrace_target class, is now a part of the inf_ptrace_target class. The only way in which this change is visible to a user is if the user turns on 'set debug target 1'. With this debug flag on, prior to this patch the user would see something like: -> native->post_startup_inferior (...) <- native->post_startup_inferior (2588939) After this patch these lines are no longer present, as the post_startup_inferior is no longer a top level target method. For me, this is an acceptable change.
2021-11-25gdb: add asserts in target.c for target_async_permittedAndrew Burgess1-1/+6
The target_async_permitted flag allows a user to override whether a target can act in async mode or not. In previous commits I have moved the checking of this flag out of the various ::can_async_p methods and into the common target.c code. In this commit I will add some additional assertions into target_is_async_p and target_async. The rules these assertions are checking are: 1. A target that returns false for target_can_async_p should never become "async enabled", and so ::is_async_p should always return false. This is being checked in target_is_async_p. 2. GDB should never try to enable async mode for a target that returns false for target_can_async_p, this is checked in target_async. There are a few places where we call the ::is_async_p method directly, in these cases we will obviously not pass through the assert in target_is_async_p, however, there are also plenty of places where we do call target_is_async_p so if GDB starts to misbehave we should catch it quickly enough. There should be no user visible changes after this commit.
2021-11-25gdb: hoist target_async_permitted checks into target.cAndrew Burgess1-0/+2
This commit moves the target_async_permitted check out of each targets ::can_async_p method and into the target_can_async_p wrapper function. I've left some asserts in the two ::can_async_p methods that I changed, which will hopefully catch any direct calls to these methods that might be added in the future. There should be no user visible changes after this commit.
2021-11-25gdb: introduce a new overload of target_can_async_pAndrew Burgess1-2/+10
There are a few places where we call the target_ops::can_async_p member function directly, instead of using the target_can_async_p wrapper. In some of these places this is because we need to ask before the target has been pushed, and in another location (in target.c) it seems unnecessary to go through the wrapper when we are already in target.c code. However, in the next commit I'd like to hoist some common checks out of target specific code into target.c. To achieve this, in this commit, I introduce a new overload of target_can_async_p which takes a target_ops pointer, and calls the ::can_async_p method directly. I then make use of the new overload where appropriate. There should be no user visible changes after this commit.
2021-11-16gdb/gdbsupport: make xstrprintf and xstrvprintf return a unique_ptrAndrew Burgess1-3/+3
The motivation is to reduce the number of places where unmanaged pointers are returned from allocation type routines. All of the callers are updated. There should be no user visible changes after this commit.
2021-10-21gdb, gdbserver: make target_waitstatus safeSimon Marchi1-2/+1
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
2021-09-23Change get_ada_task_ptid parameter typeTom Tromey1-3/+3
get_ada_task_ptid currently takes a 'long' as its 'thread' parameter type. However, on some platforms this is actually a pointer, and using 'long' can sometimes end up with the value being sign-extended. This sign extension can cause problems later, if the tid is then later used as an address again. This patch changes the parameter type to ULONGEST and updates all the uses. This approach preserves sign extension on the targets where it is apparently intended, while avoiding it on others. Co-Authored-By: John Baldwin <jhb@FreeBSD.org>
2021-09-07gdb: make thread_info::executing privateAndrew Burgess1-1/+1
Rename thread_info::executing to thread_info::m_executing, and make it private. Add a new get/set member functions, and convert GDB to make use of these. The only real change of interest in this patch is in thread.c where I have deleted the helper function set_executing_thread, and now just use the new set function thread_info::set_executing. However, the old helper function set_executing_thread included some code to reset the thread's stop_pc, so I moved this code into the new function thread_info::set_executing. However, I don't believe there is anywhere that this results in a change of behaviour, previously the executing flag was always set true through a call to set_executing_thread anyway.
2021-08-03gdb: follow-fork: push target and add thread in target_follow_forkSimon Marchi1-6/+18
In the context of ROCm-gdb [1], the ROCm target sits on top of the linux-nat target. when a process forks, it needs to carry over some data from the forking inferior to the fork child inferior. Ideally, the ROCm target would implement the follow_fork target_ops method, but there are some small problems. This patch fixes these, which helps the ROCm target, but also makes things more consistent and a bit nicer in general, I believe. The main problem is: when follow-fork-mode is "parent", target_follow_fork is called with the parent as the current inferior. When it's "child", target_follow_fork is called with the child as the current inferior. This means that target_follow_fork is sometimes called on the parent's target stack and sometimes on the child's target stack. The parent's target stack may contain targets above the process target, such as the ROCm target. So if follow-fork-child is "parent", the ROCm target would get notified of the fork and do whatever is needed. But the child's target stack, at that moment, only contains the exec and process target copied over from the parent. The child's target stack is set up by follow_fork_inferior, before calling target_follow_fork. In that case, the ROCm target wouldn't get notified of the fork. For consistency, I think it would be good to always call target_follow_fork on the parent inferior's target stack. I think it makes sense as a way to indicate "this inferior has called fork, do whatever is needed". The desired outcome of the fork (whether an inferior is created for the child, do we need to detach from the child) can be indicated by passed parameter. I therefore propose these changes: - make follow_fork_inferior always call target_follow_fork with the parent as the current inferior. That lets all targets present on the parent's target stack do some fork-related handling and push themselves on the fork child's target stack if needed. For this purpose, pass the child inferior down to target_follow_fork and follow_fork implementations. This is nullptr if no inferior is created for the child, because we want to detach from it. - as a result, in follow_fork_inferior, detach from the parent inferior (if needed) only after the target_follow_fork call. This is needed because we want to call target_follow_fork before the parent's target stack is torn down. - hand over to the targets in the parent's target stack (including the process target) the responsibility to push themselves, if needed, to the child's target stack. Also hand over the responsibility to the process target, at the same time, to create the child's initial thread (just like we do for follow_exec). - pass the child inferior to exec_on_vfork, so we don't need to swap the current inferior between parent and child. Nothing in exec_on_vfork depends on the current inferior, after this change. Although this could perhaps be replaced with just having the exec target implement follow_fork and push itself in the child's target stack, like the process target does... We would just need to make sure the process target calls beneath()->follow_fork(...). I'm not sure about this one. gdb/ChangeLog: * target.h (struct target_ops) <follow_fork>: Add inferior* parameter. (target_follow_fork): Likewise. * target.c (default_follow_fork): Likewise. (target_follow_fork): Likewise. * fbsd-nat.h (class fbsd_nat_target) <follow_fork>: Likewise. (fbsd_nat_target::follow_fork): Likewise, and call inf_ptrace_target::follow_fork. * linux-nat.h (class linux_nat_target) <follow_fork>: Likewise. * linux-nat.c (linux_nat_target::follow_fork): Likewise, and call inf_ptrace_target::follow_fork. * obsd-nat.h (obsd_nat_target) <follow_fork>: Likewise. * obsd-nat.c (obsd_nat_target::follow_fork): Likewise, and call inf_ptrace_target::follow_fork. * remote.c (class remote_target) <follow_fork>: Likewise. (remote_target::follow_fork): Likewise, and call process_stratum_target::follow_fork. * process-stratum-target.h (class process_stratum_target) <follow_fork>: New. * process-stratum-target.c (process_stratum_target::follow_fork): New. * target-delegates.c: Re-generate. [1] https://github.com/ROCm-Developer-Tools/ROCgdb Change-Id: I460bd0af850f0485e8aed4b24c6d8262a4c69929
2021-07-23gdb: remove cmd_list_element::function::sfuncSimon Marchi1-2/+2
I don't understand what the sfunc function type in cmd_list_element::function is for. Compared to cmd_simple_func_ftype, it has an extra cmd_list_element parameter, giving the callback access to the cmd_list_element for the command being invoked. This allows registering the same callback with many commands, and alter the behavior using the cmd_list_element's context. From the comment in cmd_list_element, it sounds like at some point it was the callback function type for set and show functions, hence the "s". But nowadays, it's used for many more commands that need to access the cmd_list_element object (see add_catch_command for example). I don't really see the point of having sfunc at all, since do_sfunc is just a trivial shim that changes the order of the arguments. All commands using sfunc could just as well set cmd_list_element::func to their callback directly. Therefore, remove the sfunc field in cmd_list_element and everything that goes with it. Rename cmd_const_sfunc_ftype to cmd_func_ftype and use it for cmd_list_element::func, as well as for the add_setshow commands. Change-Id: I1eb96326c9b511c293c76996cea0ebc51c70fac0
2021-07-14gdb: pass child_ptid and fork kind to target_ops::follow_forkSimon Marchi1-3/+5
This is a small cleanup I think would be nice, that I spotted while doing the following patch. gdb/ChangeLog: * target.h (struct target_ops) <follow_fork>: Add ptid and target_waitkind parameters. (target_follow_fork): Likewise. * target.c (default_follow_fork): Likewise. (target_follow_fork): Likewise. * fbsd-nat.h (class fbsd_nat_target) <follow_fork>: Likewise. * fbsd-nat.c (fbsd_nat_target::follow_fork): Likewise. * linux-nat.h (class linux_nat_target) <follow_fork>: Likewise. * linux-nat.c (linux_nat_target::follow_fork): Likewise. * obsd-nat.h (class obsd_nat_target) <follow_fork>: Likewise. * obsd-nat.c (obsd_nat_target::follow_fork): Likewise. * remote.c (class remote_target) <follow_fork>: Likewise. * target-debug.h (target_debug_print_target_waitkind): New. * target-delegates.c: Re-generate. Change-Id: I5421a542f2e19100a22b74cc333d2b235d0de3c8
2021-07-13Fix detach with target remote (PR gdb/28080)Pedro Alves1-6/+2
Commit 408f66864a1a823591b26420410c982174c239a2 ("detach in all-stop with threads running") regressed "detach" with "target remote": (gdb) detach Detaching from program: target:/any/program, process 3671843 Detaching from process 3671843 Ending remote debugging. [Inferior 1 (process 3671843) detached] In main terminate called after throwing an instance of 'gdb_exception_error' Aborted (core dumped) Here's the exception above being thrown: (top-gdb) bt #0 throw_error (error=TARGET_CLOSE_ERROR, fmt=0x555556035588 "Remote connection closed") at src/gdbsupport/common-exceptions.cc:222 #1 0x0000555555bbaa46 in remote_target::readchar (this=0x555556a11040, timeout=10000) at src/gdb/remote.c:9440 #2 0x0000555555bbb9e5 in remote_target::getpkt_or_notif_sane_1 (this=0x555556a11040, buf=0x555556a11058, forever=0, expecting_notif=0, is_notif=0x0) at src/gdb/remote.c:9928 #3 0x0000555555bbbda9 in remote_target::getpkt_sane (this=0x555556a11040, buf=0x555556a11058, forever=0) at src/gdb/remote.c:10030 #4 0x0000555555bc0e75 in remote_target::remote_hostio_send_command (this=0x555556a11040, command_bytes=13, which_packet=14, remote_errno=0x7fffffffcfd0, attachment=0x0, attachment_len=0x0) at src/gdb/remote.c:12137 #5 0x0000555555bc1b6c in remote_target::remote_hostio_close (this=0x555556a11040, fd=8, remote_errno=0x7fffffffcfd0) at src/gdb/remote.c:12455 #6 0x0000555555bc1bb4 in remote_target::fileio_close (During symbol reading: .debug_line address at offset 0x64f417 is 0 [in module build/gdb/gdb] this=0x555556a11040, fd=8, remote_errno=0x7fffffffcfd0) at src/gdb/remote.c:12462 #7 0x0000555555c9274c in target_fileio_close (fd=3, target_errno=0x7fffffffcfd0) at src/gdb/target.c:3365 #8 0x000055555595a19d in gdb_bfd_iovec_fileio_close (abfd=0x555556b9f8a0, stream=0x555556b11530) at src/gdb/gdb_bfd.c:439 #9 0x0000555555e09e3f in opncls_bclose (abfd=0x555556b9f8a0) at src/bfd/opncls.c:599 #10 0x0000555555e0a2c7 in bfd_close_all_done (abfd=0x555556b9f8a0) at src/bfd/opncls.c:847 #11 0x0000555555e0a27a in bfd_close (abfd=0x555556b9f8a0) at src/bfd/opncls.c:814 #12 0x000055555595a9d3 in gdb_bfd_close_or_warn (abfd=0x555556b9f8a0) at src/gdb/gdb_bfd.c:626 #13 0x000055555595ad29 in gdb_bfd_unref (abfd=0x555556b9f8a0) at src/gdb/gdb_bfd.c:715 #14 0x0000555555ae4730 in objfile::~objfile (this=0x555556515540, __in_chrg=<optimized out>) at src/gdb/objfiles.c:573 #15 0x0000555555ae955a in std::_Sp_counted_ptr<objfile*, (__gnu_cxx::_Lock_policy)2>::_M_dispose (this=0x555556c20db0) at /usr/include/c++/9/bits/shared_ptr_base.h:377 #16 0x000055555572b7c8 in std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release (this=0x555556c20db0) at /usr/include/c++/9/bits/shared_ptr_base.h:155 #17 0x00005555557263c3 in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::~__shared_count (this=0x555556bf0588, __in_chrg=<optimized out>) at /usr/include/c++/9/bits/shared_ptr_base.h:730 #18 0x0000555555ae745e in std::__shared_ptr<objfile, (__gnu_cxx::_Lock_policy)2>::~__shared_ptr (this=0x555556bf0580, __in_chrg=<optimized out>) at /usr/include/c++/9/bits/shared_ptr_base.h:1169 #19 0x0000555555ae747e in std::shared_ptr<objfile>::~shared_ptr (this=0x555556bf0580, __in_chrg=<optimized out>) at /usr/include/c++/9/bits/shared_ptr.h:103 #20 0x0000555555b1c1dc in __gnu_cxx::new_allocator<std::_List_node<std::shared_ptr<objfile> > >::destroy<std::shared_ptr<objfile> > (this=0x5555564cdd60, __p=0x555556bf0580) at /usr/include/c++/9/ext/new_allocator.h:153 #21 0x0000555555b1bb1d in std::allocator_traits<std::allocator<std::_List_node<std::shared_ptr<objfile> > > >::destroy<std::shared_ptr<objfile> > (__a=..., __p=0x555556bf0580) at /usr/include/c++/9/bits/alloc_traits.h:497 #22 0x0000555555b1b73e in std::__cxx11::list<std::shared_ptr<objfile>, std::allocator<std::shared_ptr<objfile> > >::_M_erase (this=0x5555564cdd60, __position=std::shared_ptr<objfile> (expired, weak count 1) = {get() = 0x555556515540}) at /usr/include/c++/9/bits/stl_list.h:1921 #23 0x0000555555b1afeb in std::__cxx11::list<std::shared_ptr<objfile>, std::allocator<std::shared_ptr<objfile> > >::erase (this=0x5555564cdd60, __position=std::shared_ptr<objfile> (expired, weak count 1) = {get() = 0x555556515540}) at /usr/include/c++/9/bits/list.tcc:158 #24 0x0000555555b19576 in program_space::remove_objfile (this=0x5555564cdd20, objfile=0x555556515540) at src/gdb/progspace.c:210 #25 0x0000555555ae4502 in objfile::unlink (this=0x555556515540) at src/gdb/objfiles.c:487 #26 0x0000555555ae5a12 in objfile_purge_solibs () at src/gdb/objfiles.c:875 #27 0x0000555555c09686 in no_shared_libraries (ignored=0x0, from_tty=1) at src/gdb/solib.c:1236 #28 0x00005555559e3f5f in detach_command (args=0x0, from_tty=1) at src/gdb/infcmd.c:2769 So frame #28 already detached the remote process, and then we're purging the shared libraries. GDB had opened remote shared libraries via the target: sysroot, so it tries closing them. GDBserver is tearing down already, so remote communication breaks down and we close the remote target and throw TARGET_CLOSE_ERROR. Note frame #14: #14 0x0000555555ae4730 in objfile::~objfile (this=0x555556515540, __in_chrg=<optimized out>) at src/gdb/objfiles.c:573 That's a dtor, thus noexcept. That's the reason for the std::terminate. Stepping back a bit, why do we still have open remote files if we've managed to detach already, and, we're debugging with "target remote"? The reason is that commit 408f66864a1a823591b26420410c982174c239a2 makes detach_command hold a reference to the target, so the remote target won't be finally closed until frame #28 returns. It's closing the target that invalidates target file I/O handles. This commit fixes the issue by not relying on target_close to invalidate the target file I/O handles, instead invalidate them immediately in remote_unpush_target. So when GDB purges the solibs, and we end up in target_fileio_close (frame #7 above), there's nothing to do, and we don't try to talk with the remote target anymore. The regression isn't seen when testing with --target_board=native-gdbserver, because that does "set sysroot" to disable the "target:" sysroot, for test run speed reasons. So this commit adds a testcase that explicitly tests detach with "set sysroot target:". gdb/ChangeLog: yyyy-mm-dd Pedro Alves <pedro@palves.net> PR gdb/28080 * remote.c (remote_unpush_target): Invalidate file I/O target handles. * target.c (fileio_handles_invalidate_target): Make extern. * target.h (fileio_handles_invalidate_target): Declare. gdb/testsuite/ChangeLog: yyyy-mm-dd Pedro Alves <pedro@palves.net> PR gdb/28080 * gdb.base/detach-sysroot-target.exp: New. * gdb.base/detach-sysroot-target.c: New. Reported-By: Jonah Graham <jonah@kichwacoders.com> Change-Id: I851234910172f42a1b30e731161376c344d2727d
2021-06-25gdb: add context getter/setter to cmd_list_elementSimon Marchi1-3/+4
Straightforward replacement of get_cmd_context / set_cmd_context with cmd_list_element methods. gdb/ChangeLog: * cli/cli-decode.h (struct cmd_list_element) <set_context, context>: New. <context>: Rename to... <m_context>: ... this. * cli/cli-decode.c (set_cmd_context, get_cmd_context): Remove. * command.h (set_cmd_context, get_cmd_context): Remove, use cmd_list_element::set_context and cmd_list_element::context everywhere instead. Change-Id: I5016b0079014e3f17d1aa449ada7954473bf2b5d
2021-05-13gdb: on exec, delegate pushing / unpushing target and adding thread to ↵Simon Marchi1-3/+5
target_ops::follow_exec On "exec", some targets need to unpush themselves from the inferior, and do some bookkeeping, like forgetting the data associated to the exec'ing inferior. One such example is the thread-db target. It does so in a special case in thread_db_target::wait, just before returning the TARGET_WAITKIND_EXECD event to its caller. We have another such case in the context of rocm-gdb [1], where the "rocm" target is pushed on top of the linux-nat target. When an exec happens, we want to unpush the rocm target from the exec'ing inferior to close some file descriptors that refer to the pre-exec address space and forget about that inferior. We then want to push the target on the inferior in which execution continues, to open the file descriptors for the post-exec address space. I think that a good way to address this cleanly is to do all this in the target_ops::follow_exec implementations. Make the process_stratum_target::follow_exec implementation have the default behavior of pushing itself to the new inferior's target stack (if execution continues in a new inferior) and add the initial thread. remote_target::follow_exec is an example of process target that wants to do a bit more than the default behavior. So it calls process_stratum_target::follow_exec first and does the extra work second. linux-thread-db (a non-process target) implements follow_exec to do some bookeeping (forget about that process' data), before handing down the event down to the process target (which hits process_stratum_target::follow_exec). gdb/ChangeLog: * target.h (struct target_ops) <follow_exec>: Add ptid_t parameter. (target_follow_exec): Likewise. * target.c (target_follow_exec): Add ptid_t parameter. * infrun.c (follow_exec): Adjust call to target_follow_exec, don't push target nor create thread. * linux-thread-db.c (class thread_db_target) <follow_exec>: New. (thread_db_target::wait): Just return on TARGET_WAITKIND_EXECD. (thread_db_target::follow_exec): New. * remote.c (class remote_target) <follow_exec>: Add ptid_t parameter. (remote_target::follow_exec): Call process_stratum_target::follow_exec. * target-delegates.c: Re-generate. Change-Id: I3f96d0ba3ea0dde6540b7e1b4d5cdb01635088c8
2021-05-12gdb: generate the prefix name for prefix commands on demandMarco Barisione1-1/+1
Previously, the prefixname field of struct cmd_list_element was manually set for prefix commands. This seems verbose and error prone as it required every single call to functions adding prefix commands to specify the prefix name while the same information can be easily generated. Historically, this was not possible as the prefix field was null for many commands, but this was fixed in commit 3f4d92ebdf7f848b5ccc9e8d8e8514c64fde1183 by Philippe Waroquiers, so we can rely on the prefix field being set when generating the prefix name. This commit also fixes a use after free in this scenario: * A command gets created via Python (using the gdb.Command class). The prefix name member is dynamically allocated. * An alias to the new command is created. The alias's prefixname is set to point to the prefixname for the original command with a direct assignment. * A new command with the same name as the Python command is created. * The object for the original Python command gets freed and its prefixname gets freed as well. * The alias is updated to point to the new command, but its prefixname is not updated so it keeps pointing to the freed one. gdb/ChangeLog: * command.h (add_prefix_cmd): Remove the prefixname argument as it can now be generated automatically. Update all callers. (add_basic_prefix_cmd): Ditto. (add_show_prefix_cmd): Ditto. (add_prefix_cmd_suppress_notification): Ditto. (add_abbrev_prefix_cmd): Ditto. * cli/cli-decode.c (add_prefix_cmd): Ditto. (add_basic_prefix_cmd): Ditto. (add_show_prefix_cmd): Ditto. (add_prefix_cmd_suppress_notification): Ditto. (add_prefix_cmd_suppress_notification): Ditto. (add_abbrev_prefix_cmd): Ditto. * cli/cli-decode.h (struct cmd_list_element): Replace the prefixname member variable with a method which generates the prefix name at runtime. Update all code reading the prefix name to use the method, and remove all code setting it. * python/py-cmd.c (cmdpy_destroyer): Remove code to free the prefixname member as it's now a method. (cmdpy_function): Determine if the command is a prefix by looking at prefixlist, not prefixname.