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2024-05-07Fix heap-use-after-free because all_objfiles_removed triggers tui_display_mainHannes Domani1-11/+2
Since gdb-10 there is a heap-use-after free happening if starting the target in TUI triggers a re-reading of symbols. It can be reproduced with: $ gdb -q -batch a.out -ex "tui enable" -ex "shell touch a.out" -ex start ==28392== Invalid read of size 1 ==28392== at 0x79E97E: lookup_global_or_static_symbol(char const*, block_enum, objfile*, domain_enum) (symtab.h:503) ==28392== by 0x79F859: lookup_global_symbol(char const*, block const*, domain_enum) (symtab.c:2641) ==28392== by 0x79F8E9: language_defn::lookup_symbol_nonlocal(char const*, block const*, domain_enum) const (symtab.c:2473) ==28392== by 0x7A66EE: lookup_symbol_aux(char const*, symbol_name_match_type, block const*, domain_enum, language, field_of_this_result*) (symtab.c:2150) ==28392== by 0x7A68C9: lookup_symbol_in_language(char const*, block const*, domain_enum, language, field_of_this_result*) (symtab.c:1958) ==28392== by 0x7A6A25: lookup_symbol(char const*, block const*, domain_enum, field_of_this_result*) (symtab.c:1970) ==28392== by 0x77120F: select_source_symtab() (source.c:319) ==28392== by 0x7EE2D5: tui_get_begin_asm_address(gdbarch**, unsigned long*) (tui-disasm.c:401) ==28392== by 0x807558: tui_display_main() (tui-winsource.c:55) ==28392== by 0x7937B5: clear_symtab_users(enum_flags<symfile_add_flag>) (functional:2464) ==28392== by 0x794F40: reread_symbols(int) (symfile.c:2690) ==28392== by 0x6497D1: run_command_1(char const*, int, run_how) (infcmd.c:398) ==28392== Address 0x4e67848 is 3,864 bytes inside a block of size 4,064 free'd ==28392== at 0x4A0A430: free (vg_replace_malloc.c:446) ==28392== by 0x936B63: _obstack_free (obstack.c:280) ==28392== by 0x79541E: reread_symbols(int) (symfile.c:2579) ==28392== by 0x6497D1: run_command_1(char const*, int, run_how) (infcmd.c:398) ==28392== by 0x4FFC45: cmd_func(cmd_list_element*, char const*, int) (cli-decode.c:2735) ==28392== by 0x7DAB50: execute_command(char const*, int) (top.c:575) ==28392== by 0x5D2B43: command_handler(char const*) (event-top.c:552) ==28392== by 0x5D3A50: command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) (event-top.c:788) ==28392== by 0x5D1F4B: gdb_rl_callback_handler(char*) (event-top.c:259) ==28392== by 0x857B3F: rl_callback_read_char (callback.c:290) ==28392== by 0x5D215D: gdb_rl_callback_read_char_wrapper_noexcept() (event-top.c:195) ==28392== by 0x5D232F: gdb_rl_callback_read_char_wrapper(void*) (event-top.c:234) The problem is that tui_display_main is called by the all_objfiles_removed hook, which tries to access the symbol cache. This symbol cache is actually stale at this point, and would have been flushed immediately afterwards by that same all_objfiles_removed hook. It's not possible to tell the hook to call the observers in a specific order, but in this case the tui_all_objfiles_removed observer is actually not needed, since it only calls tui_display_main, and a 'main' can only be found if objfiles are added, not removed. So the fix is to simply remove the tui_all_objfiles_removed observer. The clearing of the source window (if symbols were removed by e.g. 'file' without arguments) still works, since this is done by the tui_before_prompt observer. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31697 Approved-By: Tom Tromey <tom@tromey.com>
2024-05-07gdb/arch: assert that X86_XSTATE_MPX is not set for x32Andrew Burgess1-2/+6
While rebasing this series[1] past this commit: commit 4bb20a6244b7091a9a7a2ae35dfbd7e8db27550a Date: Wed Mar 20 04:13:18 2024 -0700 gdbserver: Clear X86_XSTATE_MPX bits in xcr0 on x32 I worried that there could be other paths that might result in an xcr0 value which has X86_XSTATE_MPX set in x32 mode. As everyone eventually calls amd64_create_target_description to build their target description, I figured we could assert in here that if X86_XSTATE_MPX is set then we should not be an x32 target, this will uncover any other bugs in this area. I'm not currently able to build/run any x32 binaries, so I have no way to test this, but the author of commit 4bb20a6244b7091 did test this series with that assert in place and didn't see any problems. [1] https://inbox.sourceware.org/gdb-patches/cover.1714143669.git.aburgess@redhat.com Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31511 Approved-By: Felix Willgerodt <felix.willgerodt@intel.com>
2024-05-07gdb.base/watchpoint-running.exp: Run sw watch tests even if no hw watchPedro Alves1-1/+1
The code in gdb.base/watchpoint-running.exp that is trying to skip testing with hardware watchpoints also skips testing with software watchpoints if hardware watchpoints aren't supported by the target. This fixes it. Change-Id: Iaed62ac827b32b4fd73b732ad81fa4a5aa5784ba
2024-05-07Remove gdb.base/watchpoint-running.exp leftoverPedro Alves1-2/+0
Remove accidentally leftover commented-out line from gdb.base/watchpoint-running.exp. Change-Id: Ie1c3b85997d2ca92a2159a539d24b02fd3c9e697
2024-05-07gdb/testsuite/lib/rocm: Fix with_rocm_gpu_lockLancelot SIX1-1/+1
A recent commit refactored with_rocm_gpu_lock: commit fbb0edfe60edf4ca01884151e6d9b1353aaa0a7e Date: Sat May 4 10:41:09 2024 +0200 [gdb/testsuite] Factor out proc with_lock Factor out proc with_lock from with_rocm_gpu_lock, and move required procs lock_file_acquire and lock_file_release to lib/gdb-utils.exp. This causes regressions in gdb.rocm/*.exp (as well as in downstream rocgdb). The issue can be reproduced in the following minimal test: load_lib rocm.exp set foo hello with_rocm_gpu_lock { verbose -logs $foo } The issue is that the body to execute under the lock is executed in the context of with_rocm_gpu_lock (uplevel 1 used in with_lock) instead of in the context of the "original" caller. This patch adjusted with_rocm_gpu_lock to account for the new extra frame in the call stack between the caller of with_rocm_gpu_lock and where the code execution is triggered. Approved-By: Tom de Vries <tdevries@suse.de> Change-Id: I79ce2c9615012215867ed5bb60144abe7dce28fe
2024-05-06Fix build issues with mingw toolchainBernd Edlinger2-0/+3
With a x86_64-pc-mingw32 toolchain there is a build issue whether or not the --disable-threading option is used. The problem happens because _WIN32_WINNT is defined to 0x501 before #include <mutex> which makes the compilation abort due to missing support for __gthread_cond_t in std_mutex.h, which is conditional on _WIN32_WINNT >= 0x600. Fix the case when --disable-threading is used, by only including <mutex> in gdb/complaints.c when STD_CXX_THREAD is defined. Additionally make the configure script try to #include <mutex> to automatically select --disable-threading when the header file is not able to compile. Approved-By: Tom Tromey <tom@tromey.com>
2024-05-06[gdb/testsuite] Handle ptrace operation not permitted in can_spawn_for_attachTom de Vries9-39/+135
When running the testsuite on a system with kernel.yama.ptrace_scope set to 1, we run into attach failures. Fix this by recognizing "ptrace: Operation not permitted" in can_spawn_for_attach. Tested on aarch64-linux and x86_64-linux. Approved-By: Pedro Alves <pedro@palves.net>
2024-05-06[gdb/exp] Redo cast handling for indirectionTom de Vries2-6/+4
In commit ed8fd0a342f ("[gdb/exp] Fix cast handling for indirection"), I introduced the behaviour that even though we have: ... (gdb) p *a_loc () 'a_loc' has unknown return type; cast the call to its declared return type ... we get: ... (gdb) p (char)*a_loc () $1 = 97 'a' ... In other words, the unknown return type of a_loc is inferred from the cast, effectually evaluating: ... (gdb) p (char)*(char *)a_loc () ... This is convient for the case that errno is defined as: ... #define errno (*__errno_location ()) ... and the return type of __errno_location is unknown but the macro definition is known, such that we can use: ... (gdb) p (int)errno ... instead of ... (gdb) p *(int *)__errno_location () ... However, as Pedro has pointed out in post-commit review [1], this makes it harder to reason about the semantics of an expression. For instance, this: ... (gdb) p (long long)*a_loc ()" ... would be evaluated without debug info as: ... (gdb) p (long long)*(long long *)a_loc ()" ... but with debug info as: ... (gdb) p (long long)*(char *)a_loc ()" ... Fix this by instead simply erroring out for this case: ... (gdb) p (char)*a_loc () 'a_loc' has unknown return type; cast the call to its declared return type ... Tested on x86_64-linux. Approved-By: Pedro Alves <pedro@palves.net> [1] https://sourceware.org/pipermail/gdb-patches/2024-May/208821.html
2024-05-04Fix heap-use-after-free in index-cached with --disable-threadingHannes Domani1-1/+1
If threads are disabled, either by --disable-threading explicitely, or by missing std::thread support, you get the following ASAN error when loading symbols: ==7310==ERROR: AddressSanitizer: heap-use-after-free on address 0x614000002128 at pc 0x00000098794a bp 0x7ffe37e6af70 sp 0x7ffe37e6af68 READ of size 1 at 0x614000002128 thread T0 #0 0x987949 in index_cache_store_context::store() const ../../gdb/dwarf2/index-cache.c:163 #1 0x943467 in cooked_index_worker::write_to_cache(cooked_index const*, deferred_warnings*) const ../../gdb/dwarf2/cooked-index.c:601 #2 0x1705e39 in std::function<void ()>::operator()() const /gcc/9/include/c++/9.2.0/bits/std_function.h:690 #3 0x1705e39 in gdb::task_group::impl::~impl() ../../gdbsupport/task-group.cc:38 0x614000002128 is located 232 bytes inside of 408-byte region [0x614000002040,0x6140000021d8) freed by thread T0 here: #0 0x7fd75ccf8ea5 in operator delete(void*, unsigned long) ../../.././libsanitizer/asan/asan_new_delete.cc:177 #1 0x9462e5 in cooked_index::index_for_writing() ../../gdb/dwarf2/cooked-index.h:689 #2 0x9462e5 in operator() ../../gdb/dwarf2/cooked-index.c:657 #3 0x9462e5 in _M_invoke /gcc/9/include/c++/9.2.0/bits/std_function.h:300 It's happening because cooked_index_worker::wait always returns true in this case, which tells cooked_index::wait it can delete the m_state cooked_index_worker member, but cooked_index_worker::write_to_cache tries to access it immediately afterwards. Fixed by making cooked_index_worker::wait only return true if desired_state is CACHE_DONE, same as if threading was enabled, so m_state will not be prematurely deleted. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31694 Approved-By: Tom Tromey <tom@tromey.com>
2024-05-04Remove dwarf2_per_objfile::adjustTom Tromey2-15/+0
All the calls to dwarf2_per_objfile::adjust have been removed, so we can remove this function entirely. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31261
2024-05-04Remove call to dwarf2_per_objfile::adjust from read_attribute_valueTom Tromey1-1/+0
Currently, read_attribute_value calls dwarf2_per_objfile::adjust on any address. This seems wrong, because the address may not even be in the text section. Luckily, this call is also not needed, because read_func_scope calls 'relocate', which does the same work.
2024-05-04Remove call to dwarf2_per_objfile::adjust from read_call_site_scopeTom Tromey1-5/+2
read_call_site_scope does not need to call 'adjust', because in general the call site is not a symbol address, but rather just the address of some particular call.
2024-05-04Remove more calls to dwarf2_per_objfile::adjustTom Tromey1-18/+8
As with the previous patch, this patch removes some calls to dwarf2_per_objfile::adjust. These calls are not needed by the cooked indexer, as it does not create symbols or look up symbols by address. The call in dwarf2_ranges_read is similarly not needed, as it is only used to update an addrmap; and in any case I believe this particular call is only reached by the indexer.
2024-05-04Remove call to dwarf2_per_objfile::adjust from ranges readersTom Tromey2-4/+0
dwarf2_per_objfile::adjust applies gdbarch_adjust_dwarf2_addr to an address, leaving the result unrelocated. However, this adjustment is only needed for text-section symbols -- it isn't needed for any sort of address mapping. Therefore, these calls can be removed from read_addrmap_from_aranges and create_addrmap_from_gdb_index. Approved-By: Andrew Burgess <aburgess@redhat.com>
2024-05-04[gdb/testsuite] Use unique portnum in parallel testing (check//% case)Tom de Vries2-2/+11
Make target check//% is the gdb variant of a similar gcc make target [1]. When running tests using check//%: ... $ cd build/gdb $ make check//unix/{-fPIE/-pie,-fno-PIE/-no-pie} -j2 TESTS=gdb.server/*.exp ... we get: ... $ cat build/gdb/testsuite.unix.-fPIE.-pie/cache/portnum 2427 $ cat build/gdb/testsuite.unix.-fno-PIE.-no-pie/cache/portnum 2423 ... The problem is that there are two portnum files used in parallel. Fix this by: - creating a common lockdir build/gdb/testsuite.lockdir for make target check//%, - passing this down to the runtests invocations using variable GDB_LOCK_DIR, and - using GDB_LOCK_DIR in lock_dir. Tested on aarch64-linux. Approved-By: Tom Tromey <tom@tromey.com> PR testsuite/31632 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31632 [1] https://gcc.gnu.org/install/test.html
2024-05-04[gdb/testsuite] Use unique portnum in parallel testingTom de Vries1-9/+38
When instrumenting get_portnum using: ... puts "PORTNUM: $res" ... and running: ... $ cd build/gdb $ make check-parallel -j2 TESTS=gdb.server/*.exp ... we run into: ... Running gdb.server/abspath.exp ... PORTNUM: 2345 ... and: ... Running gdb.server/bkpt-other-inferior.exp ... PORTNUM: 2345 ... This is because the test-cases are run in independent runtest invocations. Fix this by handling the parallel case in get_portnum using: - a file $objdir/cache/portnum to keep the portnum variable, and - a file $objdir/cache/portnum.lock to serialize access to it. Tested on aarch64-linux. Approved-By: Tom Tromey <tom@tromey.com>
2024-05-04[gdb/testsuite] Move gpu-parallel.lock to cache dirTom de Vries1-1/+1
The lock directory returned by lock_dir is currently $objdir. It seems possible to leave a stale lock file that blocks progress in a following run. Fix this by using a directory that is guaranteed to be initially empty when using GDB_PARALLEL, like temp or cache. In gdb/testsuite/README I found: ... cache in particular is used to share data across invocations of runtest ... which seems appropriate, so let's use cache for this. Tested on aarch64-linux. Approved-By: Tom Tromey <tom@tromey.com>
2024-05-04[gdb/testsuite] Factor out proc lock_dirTom de Vries2-1/+8
In lib/rocm.exp we have: ... set gpu_lock_filename $objdir/gpu-parallel.lock ... This decides both the lock file name and directory. Factor out a new proc lock_dir that decides on the directory, leaving just: ... set gpu_lock_filename gpu-parallel.lock ... Tested on aarch64-linux. Approved-By: Tom Tromey <tom@tromey.com>
2024-05-04[gdb/testsuite] Factor out proc with_lockTom de Vries2-54/+60
Factor out proc with_lock from with_rocm_gpu_lock, and move required procs lock_file_acquire and lock_file_release to lib/gdb-utils.exp. Tested on aarch64-linux. Approved-By: Tom Tromey <tom@tromey.com>
2024-05-04[gdb/testsuite] Make portnum a persistent globalTom de Vries1-1/+1
When instrumenting get_portnum using: ... puts "PORTNUM: $res" ... and running: ... $ cd build/gdb $ make check TESTS=gdb.server/*.exp ... we get: ... Running gdb.server/target-exec-file.exp ... PORTNUM: 2345 Running gdb.server/stop-reply-no-thread-multi.exp ... PORTNUM: 2345 PORTNUM: 2346 PORTNUM: 2347 PORTNUM: 2348 PORTNUM: 2349 PORTNUM: 2350 ... So, while get_portnum does return increasing numbers in a single test-case, it restarts at each test-case. This is a regression since the introduction of persistent globals. Fix this by using "gdb_persistent_global portnum", such that we get: ... Running gdb.server/target-exec-file.exp ... PORTNUM: 2345 Running gdb.server/stop-reply-no-thread-multi.exp ... PORTNUM: 2346 PORTNUM: 2347 PORTNUM: 2348 PORTNUM: 2349 PORTNUM: 2350 PORTNUM: 2351 ... Tested on aarch64-linux. Approved-By: Tom Tromey <tom@tromey.com>
2024-05-04[gdb/testsuite] Factor out proc get_portnumTom de Vries1-11/+29
In gdbserver_start, we have some code that determines what port number to use: ... # Port id -- either specified in baseboard file, or managed here. if [target_info exists gdb,socketport] { set portnum [target_info gdb,socketport] } else { # Bump the port number to avoid conflicts with hung ports. incr portnum } ... Factor this out into a new proc get_portnum. Tested on aarch64-linux. Approved-By: Tom Tromey <tom@tromey.com>
2024-05-03Adjust gdb_continue_to_end for WindowsPedro Alves1-0/+15
On Cygwin, supposely single-threaded programs are always multi-threaded, due to the extra threads spawned by the Cygwin runtime. Because of that, any gdb_continue_to_end call that doesn't specify "allow_extra" fails, like so: (gdb) PASS: gdb.base/langs.exp: show language at main continue Continuing. [Thread 16140.0x1fbc exited with code 0] [Thread 16140.0x2458 exited with code 0] [Thread 16140.0x3494 exited with code 0] [Inferior 1 (process 16140) exited normally] (gdb) FAIL: gdb.base/langs.exp: continue until exit at first session (the program exited) Similarly, with this simple program compiled with MinGW: $ cat ~/sleeper.c #include <windows.h> int main () { Sleep (2000); return 0; } and with a MinGW GDB, I see: (gdb) start ... (gdb) info threads Id Target Id Frame * 1 Thread 15292.0x3850 main () at /home/alves/sleeper.c:5 2 Thread 15292.0x3048 0x00007ff9630d2fb7 in ntdll!ZwWaitForWorkViaWorkerFactory () from C:\Windows\SYSTEM32\ntdll.dll (gdb) c Continuing. [Thread 15292.0x3850 exited with code 0] [Inferior 1 (process 15292) exited normally] (gdb) This commit adjusts gdb_continue_to_end to expect the thread exited messages, on Cygwin and MinGW. Change-Id: I5e410a7252c11cd9ecea632f1e00c2a7fcd69098 Approved-By: Andrew Burgess <aburgess@redhat.com>
2024-05-03[gdb/testsuite] Use save_vars to restore GDBFLAGSTom de Vries25-187/+165
There's a pattern of using: ... set saved_gdbflags $GDBFLAGS set GDBFLAGS "$GDBFLAGS ..." <do something with GDBFLAGS> set GDBFLAGS $saved_gdbflags ... Simplify this by using save_vars: ... save_vars { GDBFLAGS } { set GDBFLAGS "$GDBFLAGS ..." <do something with GDBFLAGS> } ... Tested on x86_64-linux.
2024-05-03[gdb/testsuite] Remove superfluous -quiet and -ex set width/height 0Tom de Vries9-16/+5
INTERNAL_GDBFLAGS contains: - -quiet - -iex "set width 0" - -iex "set height 0" There are test-cases that add these once more. Clean this up. Tested on x86_64-linux. PR testsuite/31649 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31649
2024-05-03[gdb/testsuite] Update INTERNAL_GDBFLAGS exampleTom de Vries1-1/+1
In commit 31c50280179 ("[gdb/testsuite] Add -q to INTERNAL_GDBFLAGS") I added -q to the INTERNAL_GDBFLAGS, but I forgot to update the INTERNAL_GDBFLAGS example in gdb/testsuite/README. Fix this by adding the -q there as well.
2024-05-03[gdb/exp] Fix cast handling for indirectionTom de Vries3-3/+76
Consider a test-case compiled without debug info, containing: ... char a = 'a'; char * a_loc (void) { return &a; } ... We get: ... (gdb) p (char)*a_loc () Cannot access memory at address 0x10 ... There's a bug in unop_ind_base_operation::evaluate that evaluates "(char)*a_loc ()" the same as: ... (gdb) p (char)*(char)a_loc () Cannot access memory at address 0x10 ... Fix this by instead evaluating it the same as: ... (gdb) p (char)*(char *)a_loc () $1 = 97 'a' ... Tested on x86_64-linux. PR exp/31693 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31693
2024-05-02Fix regression on aarch64-linux gdbserverTom Tromey4-123/+123
Commit 9a03f218 ("Fix gdb.base/watchpoint-unaligned.exp on aarch64") fixed a watchpoint bug in gdb -- but did not touch the corresponding code in gdbserver. This patch moves the gdb code into gdb/nat, so that it can be shared with gdbserver, and then changes gdbserver to use it, fixing the bug. This is yet another case where having a single back end would prevent bugs. I tested this using the AdaCore internal gdb testsuite. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29423 Approved-By: Luis Machado <luis.machado@arm.com>
2024-05-02[gdb/symtab] Work around PR gas/29517, dwarf2 caseTom de Vries4-3/+35
In commit 1d45d90934b ("[gdb/symtab] Work around PR gas/29517") we added a workaround for PR gas/29517. The problem is present in gas version 2.39, and fixed in 2.40, so the workaround is only active for gas version == 2.39. However, the problem in gas is only fixed for dwarf version >= 3, which supports DW_TAG_unspecified_type. Fix this by also activating the workaround for dwarf version == 2. Tested on x86_64-linux. Approved-by: Kevin Buettner <kevinb@redhat.com> PR symtab/31689 https://sourceware.org/bugzilla/show_bug.cgi?id=31689
2024-05-01[gdb/testsuite] Fix stray file in get_compiler_infoTom de Vries1-1/+1
When running test-case gdb.dwarf2/gdb-index-nodebug.exp with host board local-remote-host and target board remote-gdbserver-on-localhost, I get: ... $ ls build/gdb/testsuite cache compiler.i config.log config.status gdb.log gdb.sum lib Makefile outputs site.bak site.exp temp ... The file compiler.i is there because get_compiler_info uses: ... set ppout "$outdir/compiler.i" ... The file is a temporary, and as such belongs in a temp dir. Fix this by using standard_temp_file, moving the file to build/gdb/testsuite/temp/<pid>/compiler.i. Tested on x86_64-linux.
2024-05-01[gdb/testsuite] Fix stray file in gdb.dwarf2/gdb-index-nodebug.expTom de Vries1-2/+2
After running test-case gdb.dwarf2/gdb-index-nodebug.exp I have: ... $ ls build/gdb/testsuite cache config.status gdb.log lib outputs site.exp config.log gdb-index-nodebug.gdb-index gdb.sum Makefile site.bak temp ... The file gdb-index-nodebug.gdb-index doesn't belong there. It happens to be there because we do: ... set index_file ${testfile}.gdb-index set cmd "save gdb-index [file dirname ${index_file}]" ... which results in: ... (gdb) save gdb-index . ... The intention was possibly to use $binfile instead of $testfile, but using that wouldn't work for remote host. Fix this by using host_standard_output_file. Tested on x86_64-linux.
2024-04-29gdb/testsuite: Add gdb.base/memops-watchpoint.expThiago Jung Bauermann2-0/+206
Test behaviour of watchpoints triggered by libc's memset/memcpy/memmove. These functions are frequently optimized with specialized instructions that favor larger memory access operations, so make sure GDB behaves correctly in their presence. There's a separate watched variable for each function so that the testcase can test whether GDB correctly identified the watchpoint that triggered. Also, the watchpoint is 28 bytes away from the beginning of the buffer being modified, so that large memory accesses (if present) are exercised. PR testsuite/31484 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31484 Approved-by: Kevin Buettner <kevinb@redhat.com>
2024-04-29gdb/nat/linux: Fix attaching to process when it has zombie threadsThiago Jung Bauermann2-0/+54
When GDB attaches to a multi-threaded process, it calls linux_proc_attach_tgid_threads () to go through all threads found in /proc/PID/task/ and call attach_proc_task_lwp_callback () on each of them. If it does that twice without the callback reporting that a new thread was found, then it considers that all inferior threads have been found and returns. The problem is that the callback considers any thread that it hasn't attached to yet as new. This causes problems if the process has one or more zombie threads, because GDB can't attach to it and the loop will always "find" a new thread (the zombie one), and get stuck in an infinite loop. This is easy to trigger (at least on aarch64-linux and powerpc64le-linux) with the gdb.threads/attach-many-short-lived-threads.exp testcase, because its test program constantly creates and finishes joinable threads so the chance of having zombie threads is high. This problem causes the following failures: FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 8: attach (timeout) FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 8: no new threads (timeout) FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 8: set breakpoint always-inserted on (timeout) FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 8: break break_fn (timeout) FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 8: break at break_fn: 1 (timeout) FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 8: break at break_fn: 2 (timeout) FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 8: break at break_fn: 3 (timeout) FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 8: reset timer in the inferior (timeout) FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 8: print seconds_left (timeout) FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 8: detach (timeout) FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 8: set breakpoint always-inserted off (timeout) FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 8: delete all breakpoints, watchpoints, tracepoints, and catchpoints in delete_breakpoints (timeout) ERROR: breakpoints not deleted The iteration number is random, and all tests in the subsequent iterations fail too, because GDB is stuck in the attach command at the beginning of the iteration. The solution is to make linux_proc_attach_tgid_threads () remember when it has already processed a given LWP and skip it in the subsequent iterations. PR testsuite/31312 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31312 Reviewed-By: Luis Machado <luis.machado@arm.com> Approved-By: Pedro Alves <pedro@palves.net>
2024-04-29gdb/nat: Factor linux_proc_get_stat_field out of linux_common_core_of_threadThiago Jung Bauermann4-36/+62
The new function will be used in a subsequent patch to read a different stat field. The new code is believed to be equivalent to the old code, so there should be no change in GDB behaviour. The only material change was to use std::string and string_printf rather than a fixed char array to build the path to the stat file. Also, take the opportunity to move the function's documentation comment to the header file, to conform with GDB practice. Reviewed-By: Luis Machado <luis.machado@arm.com> Approved-By: Pedro Alves <pedro@palves.net>
2024-04-29gdb/nat: Use procfs(5) indexes in linux_common_core_of_threadThiago Jung Bauermann1-4/+7
The code and comment reference stat fields by made-up indexes. The procfs(5) man page, which describes the /proc/PID/stat file, has a numbered list of these fields so it's more convenient to use those numbers instead. This is currently an implementation detail inside the function so it's not really relevant with the code as-is, but a future patch will do some refactoring which will make the index more prominent. Therefore, make this change in a separate patch so that it's simpler to review. Reviewed-By: Luis Machado <luis.machado@arm.com> Approved-By: Pedro Alves <pedro@palves.net>
2024-04-29gdb/Cygwin: Fix attach pid error messagePedro Alves1-4/+13
On Cygwin, with "attach PID": - GDB first tries to interpret PID as a Windows native PID, and tries to attach to that. - if the attach fails, GDB then tries to interpret the PID as a Cygwin PID, and attach to that. If converting the user-provided PID from a Cygwin PID to a Windows PID fails, you get this: (gdb) attach 12345 Can't attach to process 0 (error 2: The system cannot find the file specified.) Note "process 0". With the fix in this commit, we'll now get: (gdb) attach 12345 Can't attach to process 12345 (error 2: The system cannot find the file specified.) I noticed this while looking at gdb.log after running gdb.base/attach.exp on Cygwin. Change-Id: I05b9dc1f3a634a822ea49bb5c61719f5e62c8514 Approved-By: Luis Machado <luis.machado@arm.com>
2024-04-29gdb/doc: document how filename arguments are formattedAndrew Burgess1-0/+78
In the following commits I intend to improve GDB's filename completion. However, how filenames should be completed is a little complex because GDB is not consistent with how it expects filename arguments to be formatted. This commit documents the current state of GDB when it comes to formatting filename arguments. Currently GDB will not correctly complete filenames inline with this documentation; GDB will either fail to complete, or complete incorrectly (i.e. the result of completion will not then be accepted by GDB). However, later commits in this series will fix completion. Approved-By: Eli Zaretskii <eliz@gnu.org>
2024-04-29gdb/remote: fix qRcmd error handlingAndrew Burgess1-10/+15
This commit: commit 3623271997a5c0d79609aa6a1f35ef61b4469054 Date: Tue Jan 30 15:55:47 2024 +0100 remote.c: Use packet_check_result Introduced a bug in the error handling of the qRcmd packet. Prior to this commit if a packet had status PACKET_OK then, if the packet contained the text "OK" we considered the packet handled. But, if the packet contained any other content (that was not an error message) then the content was printed to the user. After the above commit this was no longer the case, any non-error packet that didn't contain "OK" would be treated as an error. Currently, gdbserver doesn't exercise this path so it's not possible to write a simple test for this case. When gdbserver wishes to print output it sends back an 'O' string output packet, these packets are handled earlier in the process. Then once gdbserver has finished sending output an 'OK' packet is sent. Approved-By: Tom Tromey <tom@tromey.com>
2024-04-27Fix typo in TUI commentTom Tromey1-1/+1
tui_win_info::make_visible has a mildly misleading comment -- it says "visible" where "invisible" is meant. This patch fixes it.
2024-04-27Remove two unneeded forward declarationsTom Tromey2-4/+0
I noticed a couple of forward declarations in the TUI that aren't needed -- the declarations aren't used in the header files in which they appear. This patch removes these.
2024-04-27[gdb/remote] Fix abort on REMOTE_CLOSE_ERRORTom de Vries1-3/+56
When running test-case gdb.server/connect-with-no-symbol-file.exp on aarch64-linux (specifically, an opensuse leap 15.5 container on a fedora asahi 39 system), I run into: ... (gdb) detach^M Detaching from program: target:connect-with-no-symbol-file, process 185104^M Ending remote debugging.^M terminate called after throwing an instance of 'gdb_exception_error'^M ... The detailed backtrace of the corefile is: ... (gdb) bt #0 0x0000ffff75504f54 in raise () from /lib64/libpthread.so.0 #1 0x00000000007a86b4 in handle_fatal_signal (sig=6) at gdb/event-top.c:926 #2 <signal handler called> #3 0x0000ffff74b977b4 in raise () from /lib64/libc.so.6 #4 0x0000ffff74b98c18 in abort () from /lib64/libc.so.6 #5 0x0000ffff74ea26f4 in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib64/libstdc++.so.6 #6 0x0000ffff74ea011c in ?? () from /usr/lib64/libstdc++.so.6 #7 0x0000ffff74ea0180 in std::terminate() () from /usr/lib64/libstdc++.so.6 #8 0x0000ffff74ea0464 in __cxa_throw () from /usr/lib64/libstdc++.so.6 #9 0x0000000001548870 in throw_it (reason=RETURN_ERROR, error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed", ap=...) at gdbsupport/common-exceptions.cc:203 #10 0x0000000001548920 in throw_verror (error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed", ap=...) at gdbsupport/common-exceptions.cc:211 #11 0x0000000001548a00 in throw_error (error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed") at gdbsupport/common-exceptions.cc:226 #12 0x0000000000ac8f2c in remote_target::readchar (this=0x233d3d90, timeout=2) at gdb/remote.c:9856 #13 0x0000000000ac9f04 in remote_target::getpkt (this=0x233d3d90, buf=0x233d40a8, forever=false, is_notif=0x0) at gdb/remote.c:10326 #14 0x0000000000acf3d0 in remote_target::remote_hostio_send_command (this=0x233d3d90, command_bytes=13, which_packet=17, remote_errno=0xfffff1a3cf38, attachment=0xfffff1a3ce88, attachment_len=0xfffff1a3ce90) at gdb/remote.c:12567 #15 0x0000000000ad03bc in remote_target::fileio_fstat (this=0x233d3d90, fd=3, st=0xfffff1a3d020, remote_errno=0xfffff1a3cf38) at gdb/remote.c:12979 #16 0x0000000000c39878 in target_fileio_fstat (fd=0, sb=0xfffff1a3d020, target_errno=0xfffff1a3cf38) at gdb/target.c:3315 #17 0x00000000007eee5c in target_fileio_stream::stat (this=0x233d4400, abfd=0x2323fc40, sb=0xfffff1a3d020) at gdb/gdb_bfd.c:467 #18 0x00000000007f012c in <lambda(bfd*, void*, stat*)>::operator()(bfd *, void *, stat *) const (__closure=0x0, abfd=0x2323fc40, stream=0x233d4400, sb=0xfffff1a3d020) at gdb/gdb_bfd.c:955 #19 0x00000000007f015c in <lambda(bfd*, void*, stat*)>::_FUN(bfd *, void *, stat *) () at gdb/gdb_bfd.c:956 #20 0x0000000000f9b838 in opncls_bstat (abfd=0x2323fc40, sb=0xfffff1a3d020) at bfd/opncls.c:665 #21 0x0000000000f90adc in bfd_stat (abfd=0x2323fc40, statbuf=0xfffff1a3d020) at bfd/bfdio.c:431 #22 0x000000000065fe20 in reopen_exec_file () at gdb/corefile.c:52 #23 0x0000000000c3a3e8 in generic_mourn_inferior () at gdb/target.c:3642 #24 0x0000000000abf3f0 in remote_unpush_target (target=0x233d3d90) at gdb/remote.c:6067 #25 0x0000000000aca8b0 in remote_target::mourn_inferior (this=0x233d3d90) at gdb/remote.c:10587 #26 0x0000000000c387cc in target_mourn_inferior ( ptid=<error reading variable: Cannot access memory at address 0x2d310>) at gdb/target.c:2738 #27 0x0000000000abfff0 in remote_target::remote_detach_1 (this=0x233d3d90, inf=0x22fce540, from_tty=1) at gdb/remote.c:6421 #28 0x0000000000ac0094 in remote_target::detach (this=0x233d3d90, inf=0x22fce540, from_tty=1) at gdb/remote.c:6436 #29 0x0000000000c37c3c in target_detach (inf=0x22fce540, from_tty=1) at gdb/target.c:2526 #30 0x0000000000860424 in detach_command (args=0x0, from_tty=1) at gdb/infcmd.c:2817 #31 0x000000000060b594 in do_simple_func (args=0x0, from_tty=1, c=0x231431a0) at gdb/cli/cli-decode.c:94 #32 0x00000000006108c8 in cmd_func (cmd=0x231431a0, args=0x0, from_tty=1) at gdb/cli/cli-decode.c:2741 #33 0x0000000000c65a94 in execute_command (p=0x232e52f6 "", from_tty=1) at gdb/top.c:570 #34 0x00000000007a7d2c in command_handler (command=0x232e52f0 "") at gdb/event-top.c:566 #35 0x00000000007a8290 in command_line_handler (rl=...) at gdb/event-top.c:802 #36 0x0000000000c9092c in tui_command_line_handler (rl=...) at gdb/tui/tui-interp.c:103 #37 0x00000000007a750c in gdb_rl_callback_handler (rl=0x23385330 "detach") at gdb/event-top.c:258 #38 0x0000000000d910f4 in rl_callback_read_char () at readline/readline/callback.c:290 #39 0x00000000007a7338 in gdb_rl_callback_read_char_wrapper_noexcept () at gdb/event-top.c:194 #40 0x00000000007a73f0 in gdb_rl_callback_read_char_wrapper (client_data=0x22fbf640) at gdb/event-top.c:233 #41 0x0000000000cbee1c in stdin_event_handler (error=0, client_data=0x22fbf640) at gdb/ui.c:154 #42 0x000000000154ed60 in handle_file_event (file_ptr=0x232be730, ready_mask=1) at gdbsupport/event-loop.cc:572 #43 0x000000000154f21c in gdb_wait_for_event (block=1) at gdbsupport/event-loop.cc:693 #44 0x000000000154dec4 in gdb_do_one_event (mstimeout=-1) at gdbsupport/event-loop.cc:263 #45 0x0000000000910f98 in start_event_loop () at gdb/main.c:400 #46 0x0000000000911130 in captured_command_loop () at gdb/main.c:464 #47 0x0000000000912b5c in captured_main (data=0xfffff1a3db58) at gdb/main.c:1338 #48 0x0000000000912bf4 in gdb_main (args=0xfffff1a3db58) at gdb/main.c:1357 #49 0x00000000004170f4 in main (argc=10, argv=0xfffff1a3dcc8) at gdb/gdb.c:38 (gdb) ... The abort happens because a c++ exception escapes to c code, specifically opncls_bstat in bfd/opncls.c. Compiling with -fexceptions works around this. Fix this by catching the exception just before it escapes, in stat_trampoline and likewise in few similar spot. Add a new template catch_exceptions to do so in a consistent way. Tested on aarch64-linux. Approved-by: Pedro Alves <pedro@palves.net> PR remote/31577 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31577
2024-04-26Improve target.h & target_ops & xfer_partial descriptionsPedro Alves1-24/+51
Working backwards in terms of motivation for the patch: - When accessing memory via the xfer_partial interface, the process that we're accessing is indicated by inferior_ptid. This can be either the same process as current inferior, or a fork child which does not exist in the inferior list. This is not documented currently. This commit fixes that. - For target delegation to work, we must always make the inferior we want to call the target method on, the current inferior. This wasn't documented, AFAICT, so this commit fixes that too. I put that in the intro comment to target_ops. - I actually started writing a larger intro comment to target_ops, as there was seemingly none, which I did find odd. However, I then noticed the description closer to the top of the file. I missed it the first time, because for some reason, that intro comment is no longer at the top of the file, as #includes etc. have been added above it over the years. This commit fixes that too, by moving that intro comment to the top. Change-Id: Id21f5462947f2a0f6f3ac0c42532df62ba355914 Approved-By: Simon Marchi <simon.marchi@efficios.com> Approved-By: Tom Tromey <tom@tromey.com>
2024-04-26gdb/linux-nat: Fix mem access ptrace fallback (PR threads/31579)Pedro Alves1-3/+58
Old RHEL systems have a kernel that does not support writing memory via /proc/pid/mem. On such systems, we fallback to accessing memory via ptrace. That has a few downsides described in the "Accessing inferior memory" section at the top of linux-nat.c. The target_xfer interface for memory access uses inferior_ptid as sideband argument to indicate which process to access. Memory access is process-wide, it is not thread-specific, so inferior_ptid is sometimes pointed at a process-wide ptid_t for the memory access (i.e., a ptid that looks like {pid, 0, 0}). That is the case for any code that uses scoped_restore_current_inferior_for_memory, for example. That is what causes the issue described in PR 31579, where thread_db calls into the debugger to read memory, which reaches our ps_xfer_memory function, which does: static ps_err_e ps_xfer_memory (const struct ps_prochandle *ph, psaddr_t addr, gdb_byte *buf, size_t len, int write) { scoped_restore_current_inferior_for_memory save_inferior (ph->thread->inf); ... ret = target_read_memory (core_addr, buf, len); ... } If linux_nat_target::xfer_partial falls back to inf_ptrace_target with a pid-ptid, then the ptrace code will do the ptrace call targeting pid, the leader LWP. That may fail with ESRCH if the leader is currently running, or zombie. That is the case in the scenario in question, because thread_db is consulted for an event of a non-leader thread, before we've stopped the whole process. Fix this by having the ptrace fallback code try to find a stopped LWP to use with ptrace. I chose to handle this in the linux-nat target instead of in common code because (global) memory is a process-wide property, and this avoids having to teach all the code paths that use scoped_restore_current_inferior_for_memory to find some stopped thread to access memory through, which is a ptrace quirk. That is effectively what we used to do before we started relying on writable /proc/pid/mem. I'd rather not go back there. To trigger this on modern kernels you have to hack linux-nat.c to force the ptrace fallback code, like so: --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -3921,7 +3921,7 @@ linux_nat_target::xfer_partial (enum target_object object, poke would incorrectly write memory to the post-exec address space, while the core was trying to write to the pre-exec address space. */ - if (proc_mem_file_is_writable ()) + if (0 && proc_mem_file_is_writable ()) With that hack, I was able to confirm that the fix fixes hundreds of testsuite failures. Compared to a test run with pristine master, the hack above + this commit's fix shows that some non-stop-related tests fail, but that is expected, because those are tests that need to access memory while the program is running. (I made no effort to temporarily pause an lwp if no ptrace-stopped lwp is found.) Change-Id: I24a4f558e248aff7bc7c514a88c698f379f23180 Tested-By: Hannes Domani <ssbssa@yahoo.de> Approved-By: Andrew Burgess <aburgess@redhat.com>
2024-04-26Fix gdb.base/attach.exp --pid test skipping on native-extended-gdbserverPedro Alves1-1/+3
When testing with the native-extended-gdbserver board, gdb.base/attach.exp shows a couple failures, like so: Running /home/pedro/gdb/src/gdb/testsuite/gdb.base/attach.exp ... FAIL: gdb.base/attach.exp: do_command_attach_tests: gdb_spawn_attach_cmdline: start gdb with --pid FAIL: gdb.base/attach.exp: do_command_attach_tests: gdb_spawn_attach_cmdline: info thread (no thread) From gdb.log: builtin_spawn /home/pedro/gdb/build/gdb/testsuite/../../gdb/gdb -nw -nx -q -iex set height 0 -iex set width 0 -data-directory /home/pedro/gdb/build /gdb/data-directory -iex set auto-connect-native-target off -iex set sysroot -quiet --pid=2115260 Don't know how to attach. Try "help target". (gdb) FAIL: gdb.base/attach.exp: do_command_attach_tests: gdb_spawn_attach_cmdline: start gdb with --pid There is a check for [isnative] to skip the test on anything but target native, but that is the wrong check. native-extended-gdbserver is "isnative". Fix it by using a gdb_protocol check instead. Change-Id: I37ee730b8d6f1913b12c118838f511bd1c0b3768 Approved-By: Tom Tromey <tom@tromey.com>
2024-04-26Eliminate gdb_is_target_remote / gdb_is_target_native & friendsPedro Alves2-77/+0
After the previous patches, gdb_is_target_remote, gdb_is_target_native, and mi_is_target_remote aren't used anywhere. This commit eliminates them, along with now unnecessary helpers. Change-Id: I54f9ae1f5aed3f640e5758731cf4954e6dbb1bee Approved-By: Tom Tromey <tom@tromey.com>
2024-04-26gdb_is_target_remote -> gdb_protocol_is_remotePedro Alves18-70/+62
This is similar to the previous patch, but for gdb_protocol_is_remote. gdb_is_target_remote and its MI cousin mi_is_target_remote, use "maint print target-stack", which is unnecessary when checking whether gdb_protocol is "remote" or "extended-remote" would do. Checking gdb_protocol is more efficient, and can be done before starting GDB and running to main, unlike gdb_is_target_remote/mi_is_target_remote. This adds a new gdb_protocol_is_remote procedure, and uses it in place of gdb_is_target_remote/mi_is_target_remote throughout. There are no uses of gdb_is_target_remote/mi_is_target_remote left after this. Those will be eliminated in a following patch. In some spots, we no longer need to defer the check until after starting GDB, so the patch adjusts accordingly. Change-Id: I90267c132f942f63426f46dbca0b77dbfdf9d2ef Approved-By: Tom Tromey <tom@tromey.com>
2024-04-26gdb_is_target_native -> gdb_protocol_is_nativePedro Alves7-29/+34
gdb_is_target_native uses "maint print target-stack", which is unnecessary when checking whether gdb_protocol is empty would do. Checking gdb_protocol is more efficient, and can be done before starting GDB and running to main, unlike gdb_is_target_native. This adds a new gdb_protocol_is_native procedure, and uses it in place of gdb_is_target_native. At first, I thought that we'd end up with a few testcases needing to use gdb_is_target_native still, especially multi-target tests that connect to targets different from the default board target, but no, actually all uses of gdb_is_target_native could be converted. gdb_is_target_native will be eliminated in a following patch. In some spots, we no longer need to defer the check until after starting GDB, so the patch adjusts accordingly. Change-Id: Ia706232dbffac70f9d9740bcb89c609dbee5cee3 Approved-By: Tom Tromey <tom@tromey.com>
2024-04-26Fix "attach" failure handling with GDBserverPedro Alves3-6/+121
This fixes the same issue as the previous patch, but for "attach" instead of "run". If attaching to a process with "attach" (vAttach packet) fails, GDBserver throws an error that escapes all the way to the top level. When an error escapes all the way like that, GDBserver interprets it as a disconnection, and either goes back to waiting for a new GDB connection, or exits, if --once was specified. Here's an example: On the GDB side: ... (gdb) tar extended-remote :9999 ... Remote debugging using :9999 (gdb) attach 1 Attaching to process 1 Attaching to process 1 failed (gdb) On the GDBserver side: $ gdbserver --once --multi :9999 Listening on port 9999 Remote debugging from host 127.0.0.1, port 37464 gdbserver: Cannot attach to process 1: Operation not permitted (1) $ # gdbserver exited This is wrong, as we've connected with extended-remote/--multi. GDBserver should just report an error to vAttach, and continue connected to GDB, waiting for other commands. This commit fixes GDBserver by catching the error locally in handle_v_attach. Note we now let pid == 0 pass down to attach_inferior. That is so we get a useful textual error message to report to GDB. This fixes a couple KFAILs in gdb.base/attach.exp. Still, I thought it would be useful to add a new testcase specifically for this scenario, in case gdb.base/attach.exp is ever split and stops trying to attach again after a failed attach, with the same GDB session. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=19558 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31554 Change-Id: I25314c7e5f1435eff69cb84d57ecac13d8de3393 Approved-By: Tom Tromey <tom@tromey.com>
2024-04-26Improve vRun error reportingPedro Alves1-12/+55
After the previous commit, if starting the inferior process with "run" (vRun packet) fails, GDBserver reports an error using the "E." textual error packet. On the GDB side, however, GDB doesn't yet do anything with the textual error string. This commit improves that. This makes remote debugging output the same as native output, when possible, another small step in the "local/remote parity" project. E.g., before, against GNU/Linux GDBserver: (gdb) run Starting program: .../gdb.base/run-fail-twice/run-fail-twice.nox Running ".../gdb.base/run-fail-twice/run-fail-twice.nox" on the remote target failed After, against GNU/Linux GDBserver (same as native): (gdb) run Starting program: .../gdb.base/run-fail-twice/run-fail-twice.nox During startup program exited with code 126. To know whether we have a textual error message, extend packet_result to carry that information. While at it, convert packet_result to use factory methods, and change its std::string parameter to a plain const char *, as that it always what we have handy to pass to it. Change-Id: Ib386f267522603f554b52a885b15229c9639e870 Approved-By: Tom Tromey <tom@tromey.com>
2024-04-26Fix "run" failure handling with GDBserverPedro Alves2-0/+83
If starting the inferior process with "run" (vRun packet) fails, GDBserver throws an error that escapes all the way to the top level. When an error escapes all the way like that, GDBserver interprets it as a disconnection, and either goes back to waiting for a new GDB connection, or exits, if --once was specified. E.g., with the testcase program added by this commit, we see: On GDB side: ... (gdb) tar extended-remote :999 ... Remote debugging using :9999 (gdb) r Starting program: Running ".../gdb.base/run-fail-twice/run-fail-twice.nox" on the remote target failed (gdb) On GDBserver side: $ gdbserver --once --multi :9999 Remote debugging from host 127.0.0.1, port 34344 bash: line 1: .../gdb.base/run-fail-twice/run-fail-twice.nox: Permission denied bash: line 1: exec: .../gdb.base/run-fail-twice/run-fail-twice.nox: cannot execute: Permission denied gdbserver: During startup program exited with code 126. $ # gdbserver exited This is wrong, as we've connected with extended-remote/--multi. GDBserver should just report an error to vCont, and continue connected to GDB, waiting for other commands. This commit fixes GDBserver by catching the error locally in handle_v_run. Change-Id: Ib386f267522603f554b52a885b15229c9639e870 Approved-By: Tom Tromey <tom@tromey.com>
2024-04-26Windows: Fix run/attach hang after bad run/attachPedro Alves1-15/+20
On Cygwin, gdb.base/attach.exp exposes that an "attach" after a previously failed "attach" hangs: (gdb) PASS: gdb.base/attach.exp: do_attach_failure_tests: attach to digits-starting nonsense is prohibited attach 0 Can't attach to process 0 (error 2: The system cannot find the file specified.) (gdb) PASS: gdb.base/attach.exp: do_attach_failure_tests: attach to nonexistent process is prohibited attach 10644 FAIL: gdb.base/attach.exp: do_attach_failure_tests: first attach (timeout) The problem is that windows_nat_target::attach always returns success even if the attach fails. When we return success, the helper thread begins waiting for events (which will never come), and thus the next attach deadlocks on the do_synchronously call within windows_nat_target::attach. "run" has the same problem, which is exposed by the new gdb.base/run-fail-twice.exp testcase added in a following patch: (gdb) run Starting program: .../gdb.base/run-fail-twice/run-fail-twice.nox Error creating process .../gdb.base/run-fail-twice/run-fail-twice.nox, (error 6: The handle is invalid.) (gdb) PASS: gdb.base/run-fail-twice.exp: test: bad run 1 run Starting program: .../gdb.base/run-fail-twice/run-fail-twice.nox FAIL: gdb.base/run-fail-twice.exp: test: bad run 2 (timeout) The problem here is the same, except that this time it is windows_nat_target::create_inferior that returns the incorrect result. This commit fixes both the "attach" and "run" paths, and the latter both the Cygwin and MinGW paths. The tests mentioned above now pass on Cygwin. Confirmed the fixes manually for MinGW GDB. Change-Id: I15ec9fa279aff269d4982b00f4ea7c25ae917239 Approved-By: Tom Tromey <tom@tromey.com>