Subsumed ALU operand tests and added ALU -march failure test #19
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
@gtagliavini Please see some of the test changes mentioned in #18 for ALU ops. Let me know your thoughts on this format - we will hold of the merge until review. |
jessicamills
force-pushed
the
development
branch
from
6823e49 to
4864b32
Compare
mablinov
pushed a commit
to mablinov/corev-binutils-gdb
that referenced
this pull request
Apr 22, 2022
g++ 11.1.0 has a bug where it will emit a negative
DW_AT_data_member_location in some cases:
$ cat test.cpp
#include <memory>
int
main()
{
std::unique_ptr<int> ptr;
}
$ g++ -g test.cpp
$ llvm-dwarfdump -F a.out
...
0x00000964: DW_TAG_member
DW_AT_name [DW_FORM_strp] ("_M_head_impl")
DW_AT_decl_file [DW_FORM_data1] ("/usr/include/c++/11.1.0/tuple")
DW_AT_decl_line [DW_FORM_data1] (125)
DW_AT_decl_column [DW_FORM_data1] (0x27)
DW_AT_type [DW_FORM_ref4] (0x0000067a "default_delete<int>")
DW_AT_data_member_location [DW_FORM_sdata] (-1)
...
This leads to a GDB crash (when built with ASan, otherwise probably
garbage results), since it tries to read just before (to the left, in
ASan speak) of the value's buffer:
==888645==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6020000c52af at pc 0x7f711b239f4b bp 0x7fff356bd470 sp 0x7fff356bcc18
READ of size 1 at 0x6020000c52af thread T0
#0 0x7f711b239f4a in __interceptor_memcpy /build/gcc/src/gcc/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:827
openhwgroup#1 0x555c4977efa1 in value_contents_copy_raw /home/simark/src/binutils-gdb/gdb/value.c:1347
openhwgroup#2 0x555c497909cd in value_primitive_field(value*, long, int, type*) /home/simark/src/binutils-gdb/gdb/value.c:3126
openhwgroup#3 0x555c478f2eaa in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:333
openhwgroup#4 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
openhwgroup#5 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
openhwgroup#6 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
openhwgroup#7 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
openhwgroup#8 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
openhwgroup#9 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
openhwgroup#10 0x555c4760d45f in c_value_print_struct /home/simark/src/binutils-gdb/gdb/c-valprint.c:383
openhwgroup#11 0x555c4760df4c in c_value_print_inner(value*, ui_file*, int, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:438
openhwgroup#12 0x555c483ff9a7 in language_defn::value_print_inner(value*, ui_file*, int, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:632
openhwgroup#13 0x555c49758b68 in do_val_print /home/simark/src/binutils-gdb/gdb/valprint.c:1048
openhwgroup#14 0x555c49759b17 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) /home/simark/src/binutils-gdb/gdb/valprint.c:1151
openhwgroup#15 0x555c478f2fcb in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:335
openhwgroup#16 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
openhwgroup#17 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
openhwgroup#18 0x555c4760d45f in c_value_print_struct /home/simark/src/binutils-gdb/gdb/c-valprint.c:383
openhwgroup#19 0x555c4760df4c in c_value_print_inner(value*, ui_file*, int, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:438
openhwgroup#20 0x555c483ff9a7 in language_defn::value_print_inner(value*, ui_file*, int, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:632
openhwgroup#21 0x555c49758b68 in do_val_print /home/simark/src/binutils-gdb/gdb/valprint.c:1048
openhwgroup#22 0x555c49759b17 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) /home/simark/src/binutils-gdb/gdb/valprint.c:1151
openhwgroup#23 0x555c478f2fcb in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:335
openhwgroup#24 0x555c4760d45f in c_value_print_struct /home/simark/src/binutils-gdb/gdb/c-valprint.c:383
openhwgroup#25 0x555c4760df4c in c_value_print_inner(value*, ui_file*, int, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:438
openhwgroup#26 0x555c483ff9a7 in language_defn::value_print_inner(value*, ui_file*, int, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:632
openhwgroup#27 0x555c49758b68 in do_val_print /home/simark/src/binutils-gdb/gdb/valprint.c:1048
openhwgroup#28 0x555c49759b17 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) /home/simark/src/binutils-gdb/gdb/valprint.c:1151
openhwgroup#29 0x555c4760f04c in c_value_print(value*, ui_file*, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:587
openhwgroup#30 0x555c483ff954 in language_defn::value_print(value*, ui_file*, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:614
openhwgroup#31 0x555c49759f61 in value_print(value*, ui_file*, value_print_options const*) /home/simark/src/binutils-gdb/gdb/valprint.c:1189
openhwgroup#32 0x555c48950f70 in print_formatted /home/simark/src/binutils-gdb/gdb/printcmd.c:337
openhwgroup#33 0x555c48958eda in print_value(value*, value_print_options const&) /home/simark/src/binutils-gdb/gdb/printcmd.c:1258
openhwgroup#34 0x555c48959891 in print_command_1 /home/simark/src/binutils-gdb/gdb/printcmd.c:1367
openhwgroup#35 0x555c4895a3df in print_command /home/simark/src/binutils-gdb/gdb/printcmd.c:1458
openhwgroup#36 0x555c4767f974 in do_simple_func /home/simark/src/binutils-gdb/gdb/cli/cli-decode.c:97
openhwgroup#37 0x555c47692e25 in cmd_func(cmd_list_element*, char const*, int) /home/simark/src/binutils-gdb/gdb/cli/cli-decode.c:2475
openhwgroup#38 0x555c4936107e in execute_command(char const*, int) /home/simark/src/binutils-gdb/gdb/top.c:670
openhwgroup#39 0x555c485f1bff in catch_command_errors /home/simark/src/binutils-gdb/gdb/main.c:523
openhwgroup#40 0x555c485f249c in execute_cmdargs /home/simark/src/binutils-gdb/gdb/main.c:618
openhwgroup#41 0x555c485f6677 in captured_main_1 /home/simark/src/binutils-gdb/gdb/main.c:1317
openhwgroup#42 0x555c485f6c83 in captured_main /home/simark/src/binutils-gdb/gdb/main.c:1338
openhwgroup#43 0x555c485f6d65 in gdb_main(captured_main_args*) /home/simark/src/binutils-gdb/gdb/main.c:1363
openhwgroup#44 0x555c46e41ba8 in main /home/simark/src/binutils-gdb/gdb/gdb.c:32
openhwgroup#45 0x7f71198bcb24 in __libc_start_main (/usr/lib/libc.so.6+0x27b24)
openhwgroup#46 0x555c46e4197d in _start (/home/simark/build/binutils-gdb-one-target/gdb/gdb+0x77f197d)
0x6020000c52af is located 1 bytes to the left of 8-byte region [0x6020000c52b0,0x6020000c52b8)
allocated by thread T0 here:
#0 0x7f711b2b7459 in __interceptor_calloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cpp:154
openhwgroup#1 0x555c470acdc9 in xcalloc /home/simark/src/binutils-gdb/gdb/alloc.c:100
openhwgroup#2 0x555c49b775cd in xzalloc(unsigned long) /home/simark/src/binutils-gdb/gdbsupport/common-utils.cc:29
openhwgroup#3 0x555c4977bdeb in allocate_value_contents /home/simark/src/binutils-gdb/gdb/value.c:1029
openhwgroup#4 0x555c4977be25 in allocate_value(type*) /home/simark/src/binutils-gdb/gdb/value.c:1040
openhwgroup#5 0x555c4979030d in value_primitive_field(value*, long, int, type*) /home/simark/src/binutils-gdb/gdb/value.c:3092
openhwgroup#6 0x555c478f6280 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:501
openhwgroup#7 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
openhwgroup#8 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
openhwgroup#9 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
openhwgroup#10 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
openhwgroup#11 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
openhwgroup#12 0x555c4760d45f in c_value_print_struct /home/simark/src/binutils-gdb/gdb/c-valprint.c:383
openhwgroup#13 0x555c4760df4c in c_value_print_inner(value*, ui_file*, int, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:438
openhwgroup#14 0x555c483ff9a7 in language_defn::value_print_inner(value*, ui_file*, int, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:632
openhwgroup#15 0x555c49758b68 in do_val_print /home/simark/src/binutils-gdb/gdb/valprint.c:1048
openhwgroup#16 0x555c49759b17 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) /home/simark/src/binutils-gdb/gdb/valprint.c:1151
openhwgroup#17 0x555c478f2fcb in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:335
openhwgroup#18 0x555c478f63b2 in cp_print_value /home/simark/src/binutils-gdb/gdb/cp-valprint.c:513
openhwgroup#19 0x555c478f02ca in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:161
openhwgroup#20 0x555c4760d45f in c_value_print_struct /home/simark/src/binutils-gdb/gdb/c-valprint.c:383
openhwgroup#21 0x555c4760df4c in c_value_print_inner(value*, ui_file*, int, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:438
openhwgroup#22 0x555c483ff9a7 in language_defn::value_print_inner(value*, ui_file*, int, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:632
openhwgroup#23 0x555c49758b68 in do_val_print /home/simark/src/binutils-gdb/gdb/valprint.c:1048
openhwgroup#24 0x555c49759b17 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) /home/simark/src/binutils-gdb/gdb/valprint.c:1151
openhwgroup#25 0x555c478f2fcb in cp_print_value_fields(value*, ui_file*, int, value_print_options const*, type**, int) /home/simark/src/binutils-gdb/gdb/cp-valprint.c:335
openhwgroup#26 0x555c4760d45f in c_value_print_struct /home/simark/src/binutils-gdb/gdb/c-valprint.c:383
openhwgroup#27 0x555c4760df4c in c_value_print_inner(value*, ui_file*, int, value_print_options const*) /home/simark/src/binutils-gdb/gdb/c-valprint.c:438
openhwgroup#28 0x555c483ff9a7 in language_defn::value_print_inner(value*, ui_file*, int, value_print_options const*) const /home/simark/src/binutils-gdb/gdb/language.c:632
openhwgroup#29 0x555c49758b68 in do_val_print /home/simark/src/binutils-gdb/gdb/valprint.c:1048
Since there are some binaries with this in the wild, I think it would be
useful for GDB to work around this. I did the obvious simple thing, if
the DW_AT_data_member_location's value is -1, replace it with 0. I
added a producer check to only apply this fixup for GCC 11. The idea is
that if some other compiler ever uses a DW_AT_data_member_location value
of -1 by mistake, we don't know (before analyzing the bug at least) if
they did mean 0 or some other value. So I wouldn't want to apply the
fixup in that case.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28063
Change-Id: Ieef3459b0b9bbce8bdad838ba83b4b64e7269d42
mablinov
pushed a commit
to mablinov/corev-binutils-gdb
that referenced
this pull request
Apr 22, 2022
Starting with commit commit 1da5d0e Date: Tue Jan 4 08:02:24 2022 -0700 Change how Python architecture and language are handled we see a failure in gdb.threads/killed-outside.exp: ... Executing on target: kill -9 16622 (timeout = 300) builtin_spawn -ignore SIGHUP kill -9 16622 continue Continuing. Couldn't get registers: No such process. (gdb) [Thread 0x7ffff77c2700 (LWP 16626) exited] Program terminated with signal SIGKILL, Killed. The program no longer exists. FAIL: gdb.threads/killed-outside.exp: prompt after first continue (timeout) This is not a regression but a failure due to a change in GDB's output. Prior to the aforementioned commit, GDB has been printing the "Couldn't get registers: No such process." message twice. The second one came from (top-gdb) bt #0 amd64_linux_nat_target::fetch_registers (this=0x555557f31440 <the_amd64_linux_nat_target>, regcache=0x555558805ce0, regnum=16) at /gdb-up/gdb/amd64-linux-nat.c:225 openhwgroup#1 0x000055555640ac5f in target_ops::fetch_registers (this=0x555557d636d0 <the_thread_db_target>, arg0=0x555558805ce0, arg1=16) at /gdb-up/gdb/target-delegates.c:502 openhwgroup#2 0x000055555641a647 in target_fetch_registers (regcache=0x555558805ce0, regno=16) at /gdb-up/gdb/target.c:3945 openhwgroup#3 0x0000555556278e68 in regcache::raw_update (this=0x555558805ce0, regnum=16) at /gdb-up/gdb/regcache.c:587 openhwgroup#4 0x0000555556278f14 in readable_regcache::raw_read (this=0x555558805ce0, regnum=16, buf=0x555558881950 "") at /gdb-up/gdb/regcache.c:601 openhwgroup#5 0x00005555562792aa in readable_regcache::cooked_read (this=0x555558805ce0, regnum=16, buf=0x555558881950 "") at /gdb-up/gdb/regcache.c:690 openhwgroup#6 0x000055555627965e in readable_regcache::cooked_read_value (this=0x555558805ce0, regnum=16) at /gdb-up/gdb/regcache.c:748 openhwgroup#7 0x0000555556352a37 in sentinel_frame_prev_register (this_frame=0x555558181090, this_prologue_cache=0x5555581810a8, regnum=16) at /gdb-up/gdb/sentinel-frame.c:53 openhwgroup#8 0x0000555555fa4773 in frame_unwind_register_value (next_frame=0x555558181090, regnum=16) at /gdb-up/gdb/frame.c:1235 openhwgroup#9 0x0000555555fa420d in frame_register_unwind (next_frame=0x555558181090, regnum=16, optimizedp=0x7fffffffd570, unavailablep=0x7fffffffd574, lvalp=0x7fffffffd57c, addrp=0x7fffffffd580, realnump=0x7fffffffd578, bufferp=0x7fffffffd5b0 "") at /gdb-up/gdb/frame.c:1143 openhwgroup#10 0x0000555555fa455f in frame_unwind_register (next_frame=0x555558181090, regnum=16, buf=0x7fffffffd5b0 "") at /gdb-up/gdb/frame.c:1199 openhwgroup#11 0x00005555560178e2 in i386_unwind_pc (gdbarch=0x5555587c4a70, next_frame=0x555558181090) at /gdb-up/gdb/i386-tdep.c:1972 openhwgroup#12 0x0000555555cd2b9d in gdbarch_unwind_pc (gdbarch=0x5555587c4a70, next_frame=0x555558181090) at /gdb-up/gdb/gdbarch.c:3007 openhwgroup#13 0x0000555555fa3a5b in frame_unwind_pc (this_frame=0x555558181090) at /gdb-up/gdb/frame.c:948 openhwgroup#14 0x0000555555fa7621 in get_frame_pc (frame=0x555558181160) at /gdb-up/gdb/frame.c:2572 openhwgroup#15 0x0000555555fa7706 in get_frame_address_in_block (this_frame=0x555558181160) at /gdb-up/gdb/frame.c:2602 openhwgroup#16 0x0000555555fa77d0 in get_frame_address_in_block_if_available (this_frame=0x555558181160, pc=0x7fffffffd708) at /gdb-up/gdb/frame.c:2665 openhwgroup#17 0x0000555555fa5f8d in select_frame (fi=0x555558181160) at /gdb-up/gdb/frame.c:1890 openhwgroup#18 0x0000555555fa5bab in lookup_selected_frame (a_frame_id=..., frame_level=-1) at /gdb-up/gdb/frame.c:1720 openhwgroup#19 0x0000555555fa5e47 in get_selected_frame (message=0x0) at /gdb-up/gdb/frame.c:1810 openhwgroup#20 0x0000555555cc9c6e in get_current_arch () at /gdb-up/gdb/arch-utils.c:848 openhwgroup#21 0x000055555625b239 in gdbpy_before_prompt_hook (extlang=0x555557451f20 <extension_language_python>, current_gdb_prompt=0x555557f4d890 <top_prompt+16> "(gdb) ") at /gdb-up/gdb/python/python.c:1063 openhwgroup#22 0x0000555555f7cfbb in ext_lang_before_prompt (current_gdb_prompt=0x555557f4d890 <top_prompt+16> "(gdb) ") at /gdb-up/gdb/extension.c:922 openhwgroup#23 0x0000555555f7d442 in std::_Function_handler<void (char const*), void (*)(char const*)>::_M_invoke(std::_Any_data const&, char const*&&) (__functor=..., __args#0=@0x7fffffffd900: 0x555557f4d890 <top_prompt+16> "(gdb) ") at /usr/include/c++/7/bits/std_function.h:316 openhwgroup#24 0x0000555555f752dd in std::function<void (char const*)>::operator()(char const*) const (this=0x55555817d838, __args#0=0x555557f4d890 <top_prompt+16> "(gdb) ") at /usr/include/c++/7/bits/std_function.h:706 openhwgroup#25 0x0000555555f75100 in gdb::observers::observable<char const*>::notify (this=0x555557f49060 <gdb::observers::before_prompt>, args#0=0x555557f4d890 <top_prompt+16> "(gdb) ") at /gdb-up/gdb/../gdbsupport/observable.h:150 openhwgroup#26 0x0000555555f736dc in top_level_prompt () at /gdb-up/gdb/event-top.c:444 openhwgroup#27 0x0000555555f735ba in display_gdb_prompt (new_prompt=0x0) at /gdb-up/gdb/event-top.c:411 openhwgroup#28 0x00005555564611a7 in tui_on_command_error () at /gdb-up/gdb/tui/tui-interp.c:205 openhwgroup#29 0x0000555555c2173f in std::_Function_handler<void (), void (*)()>::_M_invoke(std::_Any_data const&) (__functor=...) at /usr/include/c++/7/bits/std_function.h:316 openhwgroup#30 0x0000555555e10c20 in std::function<void ()>::operator()() const (this=0x5555580f9028) at /usr/include/c++/7/bits/std_function.h:706 openhwgroup#31 0x0000555555e10973 in gdb::observers::observable<>::notify() const (this=0x555557f48d20 <gdb::observers::command_error>) at /gdb-up/gdb/../gdbsupport/observable.h:150 openhwgroup#32 0x00005555560e9b3f in start_event_loop () at /gdb-up/gdb/main.c:438 openhwgroup#33 0x00005555560e9bcc in captured_command_loop () at /gdb-up/gdb/main.c:481 openhwgroup#34 0x00005555560eb616 in captured_main (data=0x7fffffffddd0) at /gdb-up/gdb/main.c:1348 openhwgroup#35 0x00005555560eb67c in gdb_main (args=0x7fffffffddd0) at /gdb-up/gdb/main.c:1363 openhwgroup#36 0x0000555555c1b6b3 in main (argc=12, argv=0x7fffffffded8) at /gdb-up/gdb/gdb.c:32 Commit 1da5d0e eliminated the call to 'get_current_arch' in 'gdbpy_before_prompt_hook'. Hence, the second instance of "Couldn't get registers: No such process." does not appear anymore. Fix the failure by updating the regular expression in the test.
MaryBennett
pushed a commit
that referenced
this pull request
Oct 5, 2023
Commit 7a8de0c ("Remove ALL_BREAKPOINTS_SAFE") introduced a use-after-free in the breakpoints iterations (see below for full ASan report). This makes gdb.base/stale-infcall.exp fail when GDB is build with ASan. check_longjmp_breakpoint_for_call_dummy iterates on all breakpoints, possibly deleting the current breakpoint as well as related breakpoints. The problem arises when a breakpoint in the B->related_breakpoint chain is also B->next. In that case, deleting that related breakpoint frees the breakpoint that all_breakpoints_safe has saved. The old code worked around that by manually changing B_TMP, which was the next breakpoint saved by the "safe iterator": while (b->related_breakpoint != b) { if (b_tmp == b->related_breakpoint) b_tmp = b->related_breakpoint->next; delete_breakpoint (b->related_breakpoint); } (Note that this seemed to assume that b->related_breakpoint->next was the same as b->next->next, not sure this is guaranteed.) The new code kept the B_TMP variable, but it's not useful in that context. We can't go change the next breakpoint as saved by the safe iterator, like we did before. I suggest fixing that by saving the breakpoints to delete in a map and deleting them all at the end. Here's the full ASan report: (gdb) PASS: gdb.base/stale-infcall.exp: continue to breakpoint: break-run1 print infcall () ================================================================= ==47472==ERROR: AddressSanitizer: heap-use-after-free on address 0x611000034980 at pc 0x563f7012c7bc bp 0x7ffdf3804d70 sp 0x7ffdf3804d60 READ of size 8 at 0x611000034980 thread T0 #0 0x563f7012c7bb in next_iterator<breakpoint>::operator++() /home/smarchi/src/binutils-gdb/gdb/../gdbsupport/next-iterator.h:66 #1 0x563f702ce8c0 in basic_safe_iterator<next_iterator<breakpoint> >::operator++() /home/smarchi/src/binutils-gdb/gdb/../gdbsupport/safe-iterator.h:84 #2 0x563f7021522a in check_longjmp_breakpoint_for_call_dummy(thread_info*) /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:7611 #3 0x563f714567b1 in process_event_stop_test /home/smarchi/src/binutils-gdb/gdb/infrun.c:6881 #4 0x563f71454e07 in handle_signal_stop /home/smarchi/src/binutils-gdb/gdb/infrun.c:6769 #5 0x563f7144b680 in handle_inferior_event /home/smarchi/src/binutils-gdb/gdb/infrun.c:6023 #6 0x563f71436165 in fetch_inferior_event() /home/smarchi/src/binutils-gdb/gdb/infrun.c:4387 #7 0x563f7136ff51 in inferior_event_handler(inferior_event_type) /home/smarchi/src/binutils-gdb/gdb/inf-loop.c:42 #8 0x563f7168038d in handle_target_event /home/smarchi/src/binutils-gdb/gdb/linux-nat.c:4219 #9 0x563f72fccb6d in handle_file_event /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:573 #10 0x563f72fcd503 in gdb_wait_for_event /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:694 #11 0x563f72fcaf2b in gdb_do_one_event(int) /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:217 #12 0x563f7262b9bb in wait_sync_command_done() /home/smarchi/src/binutils-gdb/gdb/top.c:426 #13 0x563f7137a7c3 in run_inferior_call /home/smarchi/src/binutils-gdb/gdb/infcall.c:650 #14 0x563f71381295 in call_function_by_hand_dummy(value*, type*, gdb::array_view<value*>, void (*)(void*, int), void*) /home/smarchi/src/binutils-gdb/gdb/infcall.c:1332 #15 0x563f7137c0e2 in call_function_by_hand(value*, type*, gdb::array_view<value*>) /home/smarchi/src/binutils-gdb/gdb/infcall.c:780 #16 0x563f70fe5960 in evaluate_subexp_do_call(expression*, noside, value*, gdb::array_view<value*>, char const*, type*) /home/smarchi/src/binutils-gdb/gdb/eval.c:649 #17 0x563f70fe6617 in expr::operation::evaluate_funcall(type*, expression*, noside, char const*, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/eval.c:677 #18 0x563f6fd19668 in expr::operation::evaluate_funcall(type*, expression*, noside, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/expression.h:136 #19 0x563f70fe6bba in expr::var_value_operation::evaluate_funcall(type*, expression*, noside, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/eval.c:689 #20 0x563f704b71dc in expr::funcall_operation::evaluate(type*, expression*, noside) /home/smarchi/src/binutils-gdb/gdb/expop.h:2219 #21 0x563f70fe0f02 in expression::evaluate(type*, noside) /home/smarchi/src/binutils-gdb/gdb/eval.c:110 #22 0x563f71b1373e in process_print_command_args /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1319 #23 0x563f71b1391b in print_command_1 /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1332 #24 0x563f71b147ec in print_command /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1465 #25 0x563f706029b8 in do_simple_func /home/smarchi/src/binutils-gdb/gdb/cli/cli-decode.c:95 #26 0x563f7061972a in cmd_func(cmd_list_element*, char const*, int) /home/smarchi/src/binutils-gdb/gdb/cli/cli-decode.c:2735 #27 0x563f7262d0ef in execute_command(char const*, int) /home/smarchi/src/binutils-gdb/gdb/top.c:572 #28 0x563f7100ed9c in command_handler(char const*) /home/smarchi/src/binutils-gdb/gdb/event-top.c:543 #29 0x563f7101014b in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) /home/smarchi/src/binutils-gdb/gdb/event-top.c:779 #30 0x563f72777942 in tui_command_line_handler /home/smarchi/src/binutils-gdb/gdb/tui/tui-interp.c:104 #31 0x563f7100d059 in gdb_rl_callback_handler /home/smarchi/src/binutils-gdb/gdb/event-top.c:250 #32 0x7f5a80418246 in rl_callback_read_char (/usr/lib/libreadline.so.8+0x3b246) (BuildId: 092e91fc4361b0ef94561e3ae03a75f69398acbb) #33 0x563f7100ca06 in gdb_rl_callback_read_char_wrapper_noexcept /home/smarchi/src/binutils-gdb/gdb/event-top.c:192 #34 0x563f7100cc5e in gdb_rl_callback_read_char_wrapper /home/smarchi/src/binutils-gdb/gdb/event-top.c:225 #35 0x563f728c70db in stdin_event_handler /home/smarchi/src/binutils-gdb/gdb/ui.c:155 #36 0x563f72fccb6d in handle_file_event /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:573 #37 0x563f72fcd503 in gdb_wait_for_event /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:694 #38 0x563f72fcb15c in gdb_do_one_event(int) /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:264 #39 0x563f7177ec1c in start_event_loop /home/smarchi/src/binutils-gdb/gdb/main.c:412 #40 0x563f7177f12e in captured_command_loop /home/smarchi/src/binutils-gdb/gdb/main.c:476 #41 0x563f717846e4 in captured_main /home/smarchi/src/binutils-gdb/gdb/main.c:1320 #42 0x563f71784821 in gdb_main(captured_main_args*) /home/smarchi/src/binutils-gdb/gdb/main.c:1339 #43 0x563f6fcedfbd in main /home/smarchi/src/binutils-gdb/gdb/gdb.c:32 #44 0x7f5a7e43984f (/usr/lib/libc.so.6+0x2384f) (BuildId: 2f005a79cd1a8e385972f5a102f16adba414d75e) #45 0x7f5a7e439909 in __libc_start_main (/usr/lib/libc.so.6+0x23909) (BuildId: 2f005a79cd1a8e385972f5a102f16adba414d75e) #46 0x563f6fcedd84 in _start (/home/smarchi/build/binutils-gdb/gdb/gdb+0xafb0d84) (BuildId: 50bd32e6e9d5e84543e9897b8faca34858ca3995) 0x611000034980 is located 0 bytes inside of 208-byte region [0x611000034980,0x611000034a50) freed by thread T0 here: #0 0x7f5a7fce312a in operator delete(void*, unsigned long) /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_new_delete.cpp:164 #1 0x563f702bd1fa in momentary_breakpoint::~momentary_breakpoint() /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:304 #2 0x563f702771c5 in delete_breakpoint(breakpoint*) /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:12404 #3 0x563f702150a7 in check_longjmp_breakpoint_for_call_dummy(thread_info*) /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:7673 #4 0x563f714567b1 in process_event_stop_test /home/smarchi/src/binutils-gdb/gdb/infrun.c:6881 #5 0x563f71454e07 in handle_signal_stop /home/smarchi/src/binutils-gdb/gdb/infrun.c:6769 #6 0x563f7144b680 in handle_inferior_event /home/smarchi/src/binutils-gdb/gdb/infrun.c:6023 #7 0x563f71436165 in fetch_inferior_event() /home/smarchi/src/binutils-gdb/gdb/infrun.c:4387 #8 0x563f7136ff51 in inferior_event_handler(inferior_event_type) /home/smarchi/src/binutils-gdb/gdb/inf-loop.c:42 #9 0x563f7168038d in handle_target_event /home/smarchi/src/binutils-gdb/gdb/linux-nat.c:4219 #10 0x563f72fccb6d in handle_file_event /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:573 #11 0x563f72fcd503 in gdb_wait_for_event /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:694 #12 0x563f72fcaf2b in gdb_do_one_event(int) /home/smarchi/src/binutils-gdb/gdbsupport/event-loop.cc:217 #13 0x563f7262b9bb in wait_sync_command_done() /home/smarchi/src/binutils-gdb/gdb/top.c:426 #14 0x563f7137a7c3 in run_inferior_call /home/smarchi/src/binutils-gdb/gdb/infcall.c:650 #15 0x563f71381295 in call_function_by_hand_dummy(value*, type*, gdb::array_view<value*>, void (*)(void*, int), void*) /home/smarchi/src/binutils-gdb/gdb/infcall.c:1332 #16 0x563f7137c0e2 in call_function_by_hand(value*, type*, gdb::array_view<value*>) /home/smarchi/src/binutils-gdb/gdb/infcall.c:780 #17 0x563f70fe5960 in evaluate_subexp_do_call(expression*, noside, value*, gdb::array_view<value*>, char const*, type*) /home/smarchi/src/binutils-gdb/gdb/eval.c:649 #18 0x563f70fe6617 in expr::operation::evaluate_funcall(type*, expression*, noside, char const*, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/eval.c:677 #19 0x563f6fd19668 in expr::operation::evaluate_funcall(type*, expression*, noside, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/expression.h:136 #20 0x563f70fe6bba in expr::var_value_operation::evaluate_funcall(type*, expression*, noside, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/eval.c:689 #21 0x563f704b71dc in expr::funcall_operation::evaluate(type*, expression*, noside) /home/smarchi/src/binutils-gdb/gdb/expop.h:2219 #22 0x563f70fe0f02 in expression::evaluate(type*, noside) /home/smarchi/src/binutils-gdb/gdb/eval.c:110 #23 0x563f71b1373e in process_print_command_args /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1319 #24 0x563f71b1391b in print_command_1 /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1332 #25 0x563f71b147ec in print_command /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1465 #26 0x563f706029b8 in do_simple_func /home/smarchi/src/binutils-gdb/gdb/cli/cli-decode.c:95 #27 0x563f7061972a in cmd_func(cmd_list_element*, char const*, int) /home/smarchi/src/binutils-gdb/gdb/cli/cli-decode.c:2735 #28 0x563f7262d0ef in execute_command(char const*, int) /home/smarchi/src/binutils-gdb/gdb/top.c:572 #29 0x563f7100ed9c in command_handler(char const*) /home/smarchi/src/binutils-gdb/gdb/event-top.c:543 previously allocated by thread T0 here: #0 0x7f5a7fce2012 in operator new(unsigned long) /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_new_delete.cpp:95 #1 0x563f7029a9a3 in new_momentary_breakpoint<program_space*&, frame_id&, int&> /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:8129 #2 0x563f702212f6 in momentary_breakpoint_from_master /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:8169 #3 0x563f70212db1 in set_longjmp_breakpoint_for_call_dummy() /home/smarchi/src/binutils-gdb/gdb/breakpoint.c:7582 #4 0x563f713804db in call_function_by_hand_dummy(value*, type*, gdb::array_view<value*>, void (*)(void*, int), void*) /home/smarchi/src/binutils-gdb/gdb/infcall.c:1260 #5 0x563f7137c0e2 in call_function_by_hand(value*, type*, gdb::array_view<value*>) /home/smarchi/src/binutils-gdb/gdb/infcall.c:780 #6 0x563f70fe5960 in evaluate_subexp_do_call(expression*, noside, value*, gdb::array_view<value*>, char const*, type*) /home/smarchi/src/binutils-gdb/gdb/eval.c:649 #7 0x563f70fe6617 in expr::operation::evaluate_funcall(type*, expression*, noside, char const*, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/eval.c:677 #8 0x563f6fd19668 in expr::operation::evaluate_funcall(type*, expression*, noside, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/expression.h:136 #9 0x563f70fe6bba in expr::var_value_operation::evaluate_funcall(type*, expression*, noside, std::__debug::vector<std::unique_ptr<expr::operation, std::default_delete<expr::operation> >, std::allocator<std::unique_ptr<expr::operation, std::default_delete<expr::operation> > > > const&) /home/smarchi/src/binutils-gdb/gdb/eval.c:689 #10 0x563f704b71dc in expr::funcall_operation::evaluate(type*, expression*, noside) /home/smarchi/src/binutils-gdb/gdb/expop.h:2219 #11 0x563f70fe0f02 in expression::evaluate(type*, noside) /home/smarchi/src/binutils-gdb/gdb/eval.c:110 #12 0x563f71b1373e in process_print_command_args /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1319 #13 0x563f71b1391b in print_command_1 /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1332 #14 0x563f71b147ec in print_command /home/smarchi/src/binutils-gdb/gdb/printcmd.c:1465 #15 0x563f706029b8 in do_simple_func /home/smarchi/src/binutils-gdb/gdb/cli/cli-decode.c:95 #16 0x563f7061972a in cmd_func(cmd_list_element*, char const*, int) /home/smarchi/src/binutils-gdb/gdb/cli/cli-decode.c:2735 #17 0x563f7262d0ef in execute_command(char const*, int) /home/smarchi/src/binutils-gdb/gdb/top.c:572 #18 0x563f7100ed9c in command_handler(char const*) /home/smarchi/src/binutils-gdb/gdb/event-top.c:543 #19 0x563f7101014b in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) /home/smarchi/src/binutils-gdb/gdb/event-top.c:779 #20 0x563f72777942 in tui_command_line_handler /home/smarchi/src/binutils-gdb/gdb/tui/tui-interp.c:104 #21 0x563f7100d059 in gdb_rl_callback_handler /home/smarchi/src/binutils-gdb/gdb/event-top.c:250 #22 0x7f5a80418246 in rl_callback_read_char (/usr/lib/libreadline.so.8+0x3b246) (BuildId: 092e91fc4361b0ef94561e3ae03a75f69398acbb) Change-Id: Id00c17ab677f847fbf4efdf0f4038373668d3d88 Approved-By: Tom Tromey <tom@tromey.com>
MaryBennett
pushed a commit
that referenced
this pull request
Oct 5, 2023
After this commit: commit baab375 Date: Tue Jul 13 14:44:27 2021 -0400 gdb: building inferior strings from within GDB It was pointed out that a new ASan failure had been introduced which was triggered by gdb.base/internal-string-values.exp: (gdb) PASS: gdb.base/internal-string-values.exp: test_setting: all langs: lang=ada: ptype "foo" print $_gdb_maint_setting("test-settings string") ================================================================= ==80377==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x603000068034 at pc 0x564785cba682 bp 0x7ffd20644620 sp 0x7ffd20644610 READ of size 1 at 0x603000068034 thread T0 #0 0x564785cba681 in find_command_name_length(char const*) /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:2129 #1 0x564785cbacb2 in lookup_cmd_1(char const**, cmd_list_element*, cmd_list_element**, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, int, bool) /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:2186 #2 0x564785cbb539 in lookup_cmd_1(char const**, cmd_list_element*, cmd_list_element**, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, int, bool) /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:2248 #3 0x564785cbbcf3 in lookup_cmd(char const**, cmd_list_element*, char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, int, int) /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:2339 #4 0x564785c82df2 in setting_cmd /tmp/src/binutils-gdb/gdb/cli/cli-cmds.c:2219 #5 0x564785c84274 in gdb_maint_setting_internal_fn /tmp/src/binutils-gdb/gdb/cli/cli-cmds.c:2348 #6 0x564788167b3b in call_internal_function(gdbarch*, language_defn const*, value*, int, value**) /tmp/src/binutils-gdb/gdb/value.c:2321 #7 0x5647854b6ebd in expr::ada_funcall_operation::evaluate(type*, expression*, noside) /tmp/src/binutils-gdb/gdb/ada-lang.c:11254 #8 0x564786658266 in expression::evaluate(type*, noside) /tmp/src/binutils-gdb/gdb/eval.c:111 #9 0x5647871242d6 in process_print_command_args /tmp/src/binutils-gdb/gdb/printcmd.c:1322 #10 0x5647871244b3 in print_command_1 /tmp/src/binutils-gdb/gdb/printcmd.c:1335 #11 0x564787125384 in print_command /tmp/src/binutils-gdb/gdb/printcmd.c:1468 #12 0x564785caac44 in do_simple_func /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:95 #13 0x564785cc18f0 in cmd_func(cmd_list_element*, char const*, int) /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:2735 #14 0x564787c70c68 in execute_command(char const*, int) /tmp/src/binutils-gdb/gdb/top.c:574 #15 0x564786686180 in command_handler(char const*) /tmp/src/binutils-gdb/gdb/event-top.c:543 #16 0x56478668752f in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) /tmp/src/binutils-gdb/gdb/event-top.c:779 #17 0x564787dcb29a in tui_command_line_handler /tmp/src/binutils-gdb/gdb/tui/tui-interp.c:104 #18 0x56478668443d in gdb_rl_callback_handler /tmp/src/binutils-gdb/gdb/event-top.c:250 #19 0x7f4efd506246 in rl_callback_read_char (/usr/lib/libreadline.so.8+0x3b246) (BuildId: 092e91fc4361b0ef94561e3ae03a75f69398acbb) #20 0x564786683dea in gdb_rl_callback_read_char_wrapper_noexcept /tmp/src/binutils-gdb/gdb/event-top.c:192 #21 0x564786684042 in gdb_rl_callback_read_char_wrapper /tmp/src/binutils-gdb/gdb/event-top.c:225 #22 0x564787f1b119 in stdin_event_handler /tmp/src/binutils-gdb/gdb/ui.c:155 #23 0x56478862438d in handle_file_event /tmp/src/binutils-gdb/gdbsupport/event-loop.cc:573 #24 0x564788624d23 in gdb_wait_for_event /tmp/src/binutils-gdb/gdbsupport/event-loop.cc:694 #25 0x56478862297c in gdb_do_one_event(int) /tmp/src/binutils-gdb/gdbsupport/event-loop.cc:264 #26 0x564786df99f0 in start_event_loop /tmp/src/binutils-gdb/gdb/main.c:412 #27 0x564786dfa069 in captured_command_loop /tmp/src/binutils-gdb/gdb/main.c:476 #28 0x564786dff61f in captured_main /tmp/src/binutils-gdb/gdb/main.c:1320 #29 0x564786dff75c in gdb_main(captured_main_args*) /tmp/src/binutils-gdb/gdb/main.c:1339 #30 0x564785381b6d in main /tmp/src/binutils-gdb/gdb/gdb.c:32 #31 0x7f4efbc3984f (/usr/lib/libc.so.6+0x2384f) (BuildId: 2f005a79cd1a8e385972f5a102f16adba414d75e) #32 0x7f4efbc39909 in __libc_start_main (/usr/lib/libc.so.6+0x23909) (BuildId: 2f005a79cd1a8e385972f5a102f16adba414d75e) #33 0x564785381934 in _start (/tmp/build/binutils-gdb/gdb/gdb+0xabc5934) (BuildId: 90de353ac158646e7dab501b76a18a76628fca33) 0x603000068034 is located 0 bytes after 20-byte region [0x603000068020,0x603000068034) allocated by thread T0 here: #0 0x7f4efcee0cd1 in __interceptor_calloc /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_malloc_linux.cpp:77 #1 0x5647856265d8 in xcalloc /tmp/src/binutils-gdb/gdb/alloc.c:97 #2 0x564788610c6b in xzalloc(unsigned long) /tmp/src/binutils-gdb/gdbsupport/common-utils.cc:29 #3 0x56478815721a in value::allocate_contents(bool) /tmp/src/binutils-gdb/gdb/value.c:929 #4 0x564788157285 in value::allocate(type*, bool) /tmp/src/binutils-gdb/gdb/value.c:941 #5 0x56478815733a in value::allocate(type*) /tmp/src/binutils-gdb/gdb/value.c:951 #6 0x5647854ae81c in expr::ada_string_operation::evaluate(type*, expression*, noside) /tmp/src/binutils-gdb/gdb/ada-lang.c:10675 #7 0x5647854b63b8 in expr::ada_funcall_operation::evaluate(type*, expression*, noside) /tmp/src/binutils-gdb/gdb/ada-lang.c:11184 #8 0x564786658266 in expression::evaluate(type*, noside) /tmp/src/binutils-gdb/gdb/eval.c:111 #9 0x5647871242d6 in process_print_command_args /tmp/src/binutils-gdb/gdb/printcmd.c:1322 #10 0x5647871244b3 in print_command_1 /tmp/src/binutils-gdb/gdb/printcmd.c:1335 #11 0x564787125384 in print_command /tmp/src/binutils-gdb/gdb/printcmd.c:1468 #12 0x564785caac44 in do_simple_func /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:95 #13 0x564785cc18f0 in cmd_func(cmd_list_element*, char const*, int) /tmp/src/binutils-gdb/gdb/cli/cli-decode.c:2735 #14 0x564787c70c68 in execute_command(char const*, int) /tmp/src/binutils-gdb/gdb/top.c:574 #15 0x564786686180 in command_handler(char const*) /tmp/src/binutils-gdb/gdb/event-top.c:543 #16 0x56478668752f in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) /tmp/src/binutils-gdb/gdb/event-top.c:779 #17 0x564787dcb29a in tui_command_line_handler /tmp/src/binutils-gdb/gdb/tui/tui-interp.c:104 #18 0x56478668443d in gdb_rl_callback_handler /tmp/src/binutils-gdb/gdb/event-top.c:250 #19 0x7f4efd506246 in rl_callback_read_char (/usr/lib/libreadline.so.8+0x3b246) (BuildId: 092e91fc4361b0ef94561e3ae03a75f69398acbb) The problem is in cli/cli-cmds.c, in the function setting_cmd, where we do this: const char *a0 = (const char *) argv[0]->contents ().data (); Here argv[0] is a value* which we know is either a TYPE_CODE_ARRAY or a TYPE_CODE_STRING. The problem is that the above line is casting the value contents directly to a C-string, i.e. one that is assumed to have a null-terminator at the end. After the above commit this can no longer be assumed to be true. A string value will be represented just as it would be in the current language, so for Ada and Fortran the string will be an array of characters with no null-terminator at the end. My proposed solution is to copy the string contents into a std::string object, and then use the std::string::c_str() value, this will ensure that a null-terminator has been added. I had a check through GDB at places TYPE_CODE_STRING was used and couldn't see any other obvious places where this type of assumption was being made, so hopefully this is the only offender. Running the above test with ASan compiled in no longer gives an error. Reviewed-By: Tom Tromey <tom@tromey.com>
MaryBennett
pushed a commit
that referenced
this pull request
Oct 5, 2023
With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp I
run into:
...
(gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache
Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache...
(gdb) show index-cache enabled
The index cache is off.
(gdb) PASS: gdb.base/index-cache.exp: test_basic_stuff: index-cache is disabled by default
set index-cache enabled on
==================
WARNING: ThreadSanitizer: data race (pid=32248)
Write of size 1 at 0x00000321f540 by main thread:
#0 index_cache::enable() gdb/dwarf2/index-cache.c:76 (gdb+0x82cfdd)
#1 set_index_cache_enabled_command gdb/dwarf2/index-cache.c:270 (gdb+0x82d9af)
#2 bool setting::set<bool>(bool const&) gdb/command.h:353 (gdb+0x6fe5f2)
#3 do_set_command(char const*, int, cmd_list_element*) gdb/cli/cli-setshow.c:414 (gdb+0x6fcd21)
#4 execute_command(char const*, int) gdb/top.c:567 (gdb+0xff2e64)
#5 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94acc0)
#6 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94b37d)
#7 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x103467e)
#8 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94a265)
#9 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11bdd3f)
#10 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a064)
#11 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94a125)
#12 stdin_event_handler gdb/ui.c:155 (gdb+0x1074922)
#13 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d94de4)
#14 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d9551c)
#15 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d93908)
#16 start_event_loop gdb/main.c:412 (gdb+0xb5a256)
#17 captured_command_loop gdb/main.c:476 (gdb+0xb5a445)
#18 captured_main gdb/main.c:1320 (gdb+0xb5c5c5)
#19 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5c674)
#20 main gdb/gdb.c:32 (gdb+0x416776)
Previous read of size 1 at 0x00000321f540 by thread T12:
#0 index_cache::enabled() const gdb/dwarf2/index-cache.h:48 (gdb+0x82e1a6)
#1 index_cache::store(dwarf2_per_bfd*) gdb/dwarf2/index-cache.c:94 (gdb+0x82d0bc)
#2 cooked_index::maybe_write_index(dwarf2_per_bfd*) gdb/dwarf2/cooked-index.c:638 (gdb+0x7f1b97)
#3 operator() gdb/dwarf2/cooked-index.c:468 (gdb+0x7f0f24)
#4 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f285b)
#5 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952)
#6 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0)
#7 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91)
#8 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59)
#9 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660)
#10 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c)
#11 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623)
#12 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf)
#13 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f)
#14 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5)
#15 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d)
#16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2)
#17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2)
#18 pthread_once <null> (libtsan.so.0+0x4457c)
#19 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd)
#20 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224)
#21 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852)
#22 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef)
#23 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dac492)
#24 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dabdb4)
#25 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dace63)
#26 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dac294)
#27 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1daf5c6)
#28 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1daf551)
#29 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1daf506)
#30 <null> <null> (libstdc++.so.6+0xdcac2)
Location is global 'global_index_cache' of size 48 at 0x00000321f520 (gdb+0x00000321f540)
...
SUMMARY: ThreadSanitizer: data race gdb/dwarf2/index-cache.c:76 in index_cache::enable()
...
The race happens when issuing a "file $exec" command followed by a
"set index-cache enabled on" command.
The race is between:
- a worker thread reading index_cache::m_enabled to determine whether an
index-cache entry for $exec needs to be written
(due to command "file $exec"), and
- the main thread setting index_cache::m_enabled
(due to command "set index-cache enabled on").
Fix this by capturing the value of index_cache::m_enabled in the main thread,
and using the captured value in the worker thread.
Tested on x86_64-linux.
PR symtab/30392
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392
MaryBennett
pushed a commit
that referenced
this pull request
Oct 5, 2023
With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp I
run into:
...
(gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache
Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache...
==================
WARNING: ThreadSanitizer: data race (pid=12261)
Write of size 4 at 0x7b4400097d08 by main thread:
#0 bfd_open_file bfd/cache.c:584 (gdb+0x148bb92)
#1 bfd_cache_lookup_worker bfd/cache.c:261 (gdb+0x148b12a)
#2 cache_bseek bfd/cache.c:289 (gdb+0x148b324)
#3 bfd_seek bfd/bfdio.c:459 (gdb+0x1489c31)
#4 _bfd_generic_get_section_contents bfd/libbfd.c:1069 (gdb+0x14977a4)
#5 bfd_get_section_contents bfd/section.c:1606 (gdb+0x149cc7c)
#6 gdb_bfd_scan_elf_dyntag(int, bfd*, unsigned long*, unsigned long*) gdb/solib.c:1601 (gdb+0xed8eca)
#7 elf_locate_base gdb/solib-svr4.c:705 (gdb+0xec28ac)
#8 svr4_iterate_over_objfiles_in_search_order gdb/solib-svr4.c:3430 (gdb+0xeca55d)
#9 gdbarch_iterate_over_objfiles_in_search_order(gdbarch*, gdb::function_view<bool (objfile*)>, objfile*) gdb/gdbarch.c:5041 (gdb+0x537cad)
#10 find_main_name gdb/symtab.c:6270 (gdb+0xf743a5)
#11 main_language() gdb/symtab.c:6313 (gdb+0xf74499)
#12 set_initial_language() gdb/symfile.c:1700 (gdb+0xf4285c)
#13 symbol_file_add_main_1 gdb/symfile.c:1212 (gdb+0xf40e2a)
#14 symbol_file_command(char const*, int) gdb/symfile.c:1681 (gdb+0xf427d1)
#15 file_command gdb/exec.c:554 (gdb+0x94f74b)
#16 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x6d9528)
#17 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x6e0f69)
#18 execute_command(char const*, int) gdb/top.c:575 (gdb+0xff303c)
#19 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94adde)
#20 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94b49b)
#21 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x103479c)
#22 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94a383)
#23 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11bde5d)
#24 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a182)
#25 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94a243)
#26 stdin_event_handler gdb/ui.c:155 (gdb+0x1074a40)
#27 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d94f02)
#28 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d9563a)
#29 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d93a26)
#30 start_event_loop gdb/main.c:412 (gdb+0xb5a374)
#31 captured_command_loop gdb/main.c:476 (gdb+0xb5a563)
#32 captured_main gdb/main.c:1320 (gdb+0xb5c6e3)
#33 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5c792)
#34 main gdb/gdb.c:32 (gdb+0x416776)
Previous read of size 1 at 0x7b4400097d08 by thread T12:
#0 bfd_check_format_matches bfd/format.c:323 (gdb+0x1492db4)
#1 bfd_check_format bfd/format.c:94 (gdb+0x1492104)
#2 build_id_bfd_get(bfd*) gdb/build-id.c:42 (gdb+0x6648f7)
#3 index_cache::store(dwarf2_per_bfd*, index_cache_store_context*) gdb/dwarf2/index-cache.c:110 (gdb+0x82d205)
#4 cooked_index::maybe_write_index(dwarf2_per_bfd*) gdb/dwarf2/cooked-index.c:640 (gdb+0x7f1bf1)
#5 operator() gdb/dwarf2/cooked-index.c:470 (gdb+0x7f0f40)
#6 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f28f7)
#7 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952)
#8 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0)
#9 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91)
#10 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59)
#11 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660)
#12 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c)
#13 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623)
#14 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf)
#15 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f)
#16 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5)
#17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d)
#18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2)
#19 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2)
#20 pthread_once <null> (libtsan.so.0+0x4457c)
#21 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd)
#22 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224)
#23 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852)
#24 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef)
#25 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dac5b0)
#26 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dabed2)
#27 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dacf81)
#28 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dac3b2)
#29 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1daf6e4)
#30 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1daf66f)
#31 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1daf624)
#32 <null> <null> (libstdc++.so.6+0xdcac2)
...
SUMMARY: ThreadSanitizer: data race bfd/cache.c:584 in bfd_open_file
...
The race happens when issuing the "file $exec" command.
The race is between:
- a worker thread getting the build id while writing the index cache, and in
the process reading bfd::format, and
- the main thread calling find_main_name, and in the process setting
bfd::cacheable.
The two bitfields bfd::cacheable and bfd::format share the same bitfield
container.
Fix this by capturing the build id in the main thread, and using the captured
value in the worker thread.
Likewise for the dwz build id, which likely suffers from the same issue.
While we're at it, also move the creation of the cache directory to
the index_cache_store_context constructor, to:
- make sure there's no race between subsequent file commands, and
- issue any related warning or error messages during the file command.
Tested on x86_64-linux.
Approved-By: Tom Tromey <tom@tromey.com>
PR symtab/30392
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392
MaryBennett
pushed a commit
that referenced
this pull request
Oct 5, 2023
With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp I
run into:
...
(gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache
Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache...
==================
WARNING: ThreadSanitizer: data race (pid=24296)
Write of size 1 at 0x7b200000420d by main thread:
#0 queue_comp_unit gdb/dwarf2/read.c:5564 (gdb+0x8939ce)
#1 dw2_do_instantiate_symtab gdb/dwarf2/read.c:1754 (gdb+0x885b96)
#2 dw2_instantiate_symtab gdb/dwarf2/read.c:1792 (gdb+0x885d86)
#3 dw2_expand_symtabs_matching_one(dwarf2_per_cu_data*, dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>, gdb::function_view<bool (compunit_symtab*)>) gdb/dwarf2/read.c:3042 (gdb+0x88ac77)
#4 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16915 (gdb+0x8c1c8a)
#5 objfile::lookup_symbol(block_enum, char const*, domain_enum) gdb/symfile-debug.c:288 (gdb+0xf389a1)
#6 lookup_symbol_via_quick_fns gdb/symtab.c:2385 (gdb+0xf66403)
#7 lookup_symbol_in_objfile gdb/symtab.c:2516 (gdb+0xf66a67)
#8 operator() gdb/symtab.c:2562 (gdb+0xf66bbe)
#9 operator() gdb/../gdbsupport/function-view.h:305 (gdb+0xf76ffd)
#10 _FUN gdb/../gdbsupport/function-view.h:299 (gdb+0xf77054)
#11 gdb::function_view<bool (objfile*)>::operator()(objfile*) const gdb/../gdbsupport/function-view.h:289 (gdb+0xc3f5e3)
#12 svr4_iterate_over_objfiles_in_search_order gdb/solib-svr4.c:3455 (gdb+0xeca793)
#13 gdbarch_iterate_over_objfiles_in_search_order(gdbarch*, gdb::function_view<bool (objfile*)>, objfile*) gdb/gdbarch.c:5041 (gdb+0x537cad)
#14 lookup_global_or_static_symbol gdb/symtab.c:2559 (gdb+0xf66e47)
#15 lookup_global_symbol(char const*, block const*, domain_enum) gdb/symtab.c:2615 (gdb+0xf670cc)
#16 language_defn::lookup_symbol_nonlocal(char const*, block const*, domain_enum) const gdb/symtab.c:2447 (gdb+0xf666ba)
#17 lookup_symbol_aux gdb/symtab.c:2123 (gdb+0xf655ff)
#18 lookup_symbol_in_language(char const*, block const*, domain_enum, language, field_of_this_result*) gdb/symtab.c:1931 (gdb+0xf646f7)
#19 set_initial_language() gdb/symfile.c:1708 (gdb+0xf429c0)
#20 symbol_file_add_main_1 gdb/symfile.c:1212 (gdb+0xf40f54)
#21 symbol_file_command(char const*, int) gdb/symfile.c:1681 (gdb+0xf428fb)
#22 file_command gdb/exec.c:554 (gdb+0x94f875)
#23 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x6d9528)
#24 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x6e0f69)
#25 execute_command(char const*, int) gdb/top.c:575 (gdb+0xff3166)
#26 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94af08)
#27 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94b5c5)
#28 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x10348c6)
#29 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94a4ad)
#30 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11bdf87)
#31 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a2ac)
#32 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94a36d)
#33 stdin_event_handler gdb/ui.c:155 (gdb+0x1074b6a)
#34 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d9502c)
#35 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d95764)
#36 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d93b50)
#37 start_event_loop gdb/main.c:412 (gdb+0xb5a49e)
#38 captured_command_loop gdb/main.c:476 (gdb+0xb5a68d)
#39 captured_main gdb/main.c:1320 (gdb+0xb5c80d)
#40 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5c8bc)
#41 main gdb/gdb.c:32 (gdb+0x416776)
Previous read of size 1 at 0x7b200000420d by thread T12:
#0 write_gdbindex gdb/dwarf2/index-write.c:1229 (gdb+0x8310c8)
#1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1484 (gdb+0x83232f)
#2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context*) gdb/dwarf2/index-cache.c:177 (gdb+0x82d62b)
#3 cooked_index::maybe_write_index(dwarf2_per_bfd*) gdb/dwarf2/cooked-index.c:640 (gdb+0x7f1bf7)
#4 operator() gdb/dwarf2/cooked-index.c:470 (gdb+0x7f0f40)
#5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f2909)
#6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952)
#7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0)
#8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91)
#9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59)
#10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660)
#11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c)
#12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623)
#13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf)
#14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f)
#15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5)
#16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d)
#17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2)
#18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2)
#19 pthread_once <null> (libtsan.so.0+0x4457c)
#20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd)
#21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224)
#22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852)
#23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef)
#24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dac6da)
#25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dabffc)
#26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dad0ab)
#27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dac4dc)
#28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1daf80e)
#29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1daf799)
#30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1daf74e)
#31 <null> <null> (libstdc++.so.6+0xdcac2)
...
SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:5564 in queue_comp_unit
...
The race happens when issuing the "file $exec" command.
The race is between:
- a worker thread writing the index cache, and in the process reading
dwarf2_per_cu_data::is_debug_type, and
- the main thread expanding the CU containing main, and in the process setting
dwarf2_per_cu_data::queued.
The two bitfields dwarf2_per_cu_data::queue and
dwarf2_per_cu_data::is_debug_type share the same bitfield container.
Fix this by making dwarf2_per_cu_data::queued a packed<bool, 1>.
Tested on x86_64-linux.
Approved-By: Tom Tromey <tom@tromey.com>
PR symtab/30392
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392
MaryBennett
pushed a commit
that referenced
this pull request
Oct 5, 2023
…s_debug_type}
With gdb build with -fsanitize=thread and test-case gdb.base/index-cache.exp
and target board debug-types, I run into:
...
(gdb) file build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache
Reading symbols from build/gdb/testsuite/outputs/gdb.base/index-cache/index-cache...
==================
WARNING: ThreadSanitizer: data race (pid=9654)
Write of size 1 at 0x7b200000420d by main thread:
#0 dwarf2_per_cu_data::get_header() const gdb/dwarf2/read.c:21513 (gdb+0x8d1eee)
#1 dwarf2_per_cu_data::addr_size() const gdb/dwarf2/read.c:21524 (gdb+0x8d1f4e)
#2 dwarf2_cu::addr_type() const gdb/dwarf2/cu.c:112 (gdb+0x806327)
#3 set_die_type gdb/dwarf2/read.c:21932 (gdb+0x8d3870)
#4 read_base_type gdb/dwarf2/read.c:15448 (gdb+0x8bcacb)
#5 read_type_die_1 gdb/dwarf2/read.c:19832 (gdb+0x8cc0a5)
#6 read_type_die gdb/dwarf2/read.c:19767 (gdb+0x8cbe6d)
#7 lookup_die_type gdb/dwarf2/read.c:19739 (gdb+0x8cbdc7)
#8 die_type gdb/dwarf2/read.c:19593 (gdb+0x8cb68a)
#9 read_subroutine_type gdb/dwarf2/read.c:14648 (gdb+0x8b998e)
#10 read_type_die_1 gdb/dwarf2/read.c:19792 (gdb+0x8cbf2f)
#11 read_type_die gdb/dwarf2/read.c:19767 (gdb+0x8cbe6d)
#12 read_func_scope gdb/dwarf2/read.c:10154 (gdb+0x8a4f36)
#13 process_die gdb/dwarf2/read.c:6667 (gdb+0x898daa)
#14 read_file_scope gdb/dwarf2/read.c:7682 (gdb+0x89bad8)
#15 process_die gdb/dwarf2/read.c:6654 (gdb+0x898ced)
#16 process_full_comp_unit gdb/dwarf2/read.c:6418 (gdb+0x8981de)
#17 process_queue gdb/dwarf2/read.c:5690 (gdb+0x894433)
#18 dw2_do_instantiate_symtab gdb/dwarf2/read.c:1770 (gdb+0x88623a)
#19 dw2_instantiate_symtab gdb/dwarf2/read.c:1792 (gdb+0x886300)
#20 dw2_expand_symtabs_matching_one(dwarf2_per_cu_data*, dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>, gdb::function_view<bool (compunit_symtab*)>) gdb/dwarf2/read.c:3042 (gdb+0x88b1f1)
#21 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16917 (gdb+0x8c228e)
#22 objfile::lookup_symbol(block_enum, char const*, domain_enum) gdb/symfile-debug.c:288 (gdb+0xf39055)
#23 lookup_symbol_via_quick_fns gdb/symtab.c:2385 (gdb+0xf66ab7)
#24 lookup_symbol_in_objfile gdb/symtab.c:2516 (gdb+0xf6711b)
#25 operator() gdb/symtab.c:2562 (gdb+0xf67272)
#26 operator() gdb/../gdbsupport/function-view.h:305 (gdb+0xf776b1)
#27 _FUN gdb/../gdbsupport/function-view.h:299 (gdb+0xf77708)
#28 gdb::function_view<bool (objfile*)>::operator()(objfile*) const gdb/../gdbsupport/function-view.h:289 (gdb+0xc3fc97)
#29 svr4_iterate_over_objfiles_in_search_order gdb/solib-svr4.c:3455 (gdb+0xecae47)
#30 gdbarch_iterate_over_objfiles_in_search_order(gdbarch*, gdb::function_view<bool (objfile*)>, objfile*) gdb/gdbarch.c:5041 (gdb+0x537cad)
#31 lookup_global_or_static_symbol gdb/symtab.c:2559 (gdb+0xf674fb)
#32 lookup_global_symbol(char const*, block const*, domain_enum) gdb/symtab.c:2615 (gdb+0xf67780)
#33 language_defn::lookup_symbol_nonlocal(char const*, block const*, domain_enum) const gdb/symtab.c:2447 (gdb+0xf66d6e)
#34 lookup_symbol_aux gdb/symtab.c:2123 (gdb+0xf65cb3)
#35 lookup_symbol_in_language(char const*, block const*, domain_enum, language, field_of_this_result*) gdb/symtab.c:1931 (gdb+0xf64dab)
#36 set_initial_language() gdb/symfile.c:1708 (gdb+0xf43074)
#37 symbol_file_add_main_1 gdb/symfile.c:1212 (gdb+0xf41608)
#38 symbol_file_command(char const*, int) gdb/symfile.c:1681 (gdb+0xf42faf)
#39 file_command gdb/exec.c:554 (gdb+0x94ff29)
#40 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x6d9528)
#41 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x6e0f69)
#42 execute_command(char const*, int) gdb/top.c:575 (gdb+0xff379c)
#43 command_handler(char const*) gdb/event-top.c:552 (gdb+0x94b5bc)
#44 command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:788 (gdb+0x94bc79)
#45 tui_command_line_handler gdb/tui/tui-interp.c:104 (gdb+0x1034efc)
#46 gdb_rl_callback_handler gdb/event-top.c:259 (gdb+0x94ab61)
#47 rl_callback_read_char readline/readline/callback.c:290 (gdb+0x11be4ef)
#48 gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195 (gdb+0x94a960)
#49 gdb_rl_callback_read_char_wrapper gdb/event-top.c:234 (gdb+0x94aa21)
#50 stdin_event_handler gdb/ui.c:155 (gdb+0x10751a0)
#51 handle_file_event gdbsupport/event-loop.cc:573 (gdb+0x1d95bac)
#52 gdb_wait_for_event gdbsupport/event-loop.cc:694 (gdb+0x1d962e4)
#53 gdb_do_one_event(int) gdbsupport/event-loop.cc:264 (gdb+0x1d946d0)
#54 start_event_loop gdb/main.c:412 (gdb+0xb5ab52)
#55 captured_command_loop gdb/main.c:476 (gdb+0xb5ad41)
#56 captured_main gdb/main.c:1320 (gdb+0xb5cec1)
#57 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xb5cf70)
#58 main gdb/gdb.c:32 (gdb+0x416776)
Previous read of size 1 at 0x7b200000420d by thread T11:
#0 write_gdbindex gdb/dwarf2/index-write.c:1229 (gdb+0x831630)
#1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1484 (gdb+0x832897)
#2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/index-cache.c:173 (gdb+0x82db8d)
#3 cooked_index::maybe_write_index(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/cooked-index.c:645 (gdb+0x7f1d49)
#4 operator() gdb/dwarf2/cooked-index.c:474 (gdb+0x7f0f31)
#5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x7f2a13)
#6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x700952)
#7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x7381a0)
#8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x737e91)
#9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x737b59)
#10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x738660)
#11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x73825c)
#12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x733623)
#13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x732bdf)
#14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x734c4f)
#15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x733bc5)
#16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x73300d)
#17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x7330b2)
#18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x7330f2)
#19 pthread_once <null> (libtsan.so.0+0x4457c)
#20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72f5dd)
#21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x733224)
#22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x732852)
#23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x737bef)
#24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x1dad25a)
#25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x1dacb7c)
#26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1dadc2b)
#27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1dad05c)
#28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1db038e)
#29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1db0319)
#30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1db02ce)
#31 <null> <null> (libstdc++.so.6+0xdcac2)
...
SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:21513 in dwarf2_per_cu_data::get_header() const
...
The race happens when issuing the "file $exec" command.
The race is between:
- a worker thread writing the index cache, and in the process reading
dwarf2_per_cu_data::is_debug_type, and
- the main thread writing to dwarf2_per_cu_data::m_header_read_in.
The two bitfields dwarf2_per_cu_data::m_header_read_in and
dwarf2_per_cu_data::is_debug_type share the same bitfield container.
Fix this by making dwarf2_per_cu_data::m_header_read_in a packed<bool, 1>.
Tested on x86_64-linux.
Approved-By: Tom Tromey <tom@tromey.com>
PR symtab/30392
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30392
MaryBennett
pushed a commit
that referenced
this pull request
Oct 5, 2023
With gdb build with -fsanitize=thread, and the exec from test-case
gdb.base/index-cache.exp, I run into:
...
$ rm -f ~/.cache/gdb/*; \
gdb -q -batch -iex "set index-cache enabled on" index-cache \
-ex "print foobar"
...
WARNING: ThreadSanitizer: data race (pid=23970)
Write of size 1 at 0x7b200000410d by main thread:
#0 dw_expand_symtabs_matching_file_matcher(dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>) gdb/dwarf2/read.c:3077 (gdb+0x7ac54e)
#1 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16812 (gdb+0x7d039f)
#2 objfile::map_symtabs_matching_filename(char const*, char const*, gdb::function_view<bool (symtab*)>) gdb/symfile-debug.c:219 (gdb+0xda5aee)
#3 iterate_over_symtabs(char const*, gdb::function_view<bool (symtab*)>) gdb/symtab.c:648 (gdb+0xdc439d)
#4 lookup_symtab(char const*) gdb/symtab.c:662 (gdb+0xdc44a2)
#5 classify_name gdb/c-exp.y:3083 (gdb+0x61afec)
#6 c_yylex gdb/c-exp.y:3251 (gdb+0x61dd13)
#7 c_yyparse() build/gdb/c-exp.c.tmp:1988 (gdb+0x61f07e)
#8 c_parse(parser_state*) gdb/c-exp.y:3417 (gdb+0x62d864)
#9 language_defn::parser(parser_state*) const gdb/language.c:598 (gdb+0x9771c5)
#10 parse_exp_in_context gdb/parse.c:414 (gdb+0xb10a9b)
#11 parse_expression(char const*, innermost_block_tracker*, enum_flags<parser_flag>) gdb/parse.c:462 (gdb+0xb110ae)
#12 process_print_command_args gdb/printcmd.c:1321 (gdb+0xb4bf0c)
#13 print_command_1 gdb/printcmd.c:1335 (gdb+0xb4ca2a)
#14 print_command gdb/printcmd.c:1468 (gdb+0xb4cd5a)
#15 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x65b078)
#16 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x65ed53)
#17 execute_command(char const*, int) gdb/top.c:575 (gdb+0xe3a76a)
#18 catch_command_errors gdb/main.c:518 (gdb+0xa1837d)
#19 execute_cmdargs gdb/main.c:617 (gdb+0xa1853f)
#20 captured_main_1 gdb/main.c:1289 (gdb+0xa1aa58)
#21 captured_main gdb/main.c:1310 (gdb+0xa1b95a)
#22 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xa1b95a)
#23 main gdb/gdb.c:39 (gdb+0x42506a)
Previous read of size 1 at 0x7b200000410d by thread T1:
#0 write_gdbindex gdb/dwarf2/index-write.c:1214 (gdb+0x75bb30)
#1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1469 (gdb+0x75f803)
#2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/index-cache.c:173 (gdb+0x755a36)
#3 cooked_index::maybe_write_index(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/cooked-index.c:642 (gdb+0x71c96d)
#4 operator() gdb/dwarf2/cooked-index.c:471 (gdb+0x71c96d)
#5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x71c96d)
#6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x72a57c)
#7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x72a5db)
#8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x72a5db)
#9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x72a5db)
#10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x72a5db)
#11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x72a5db)
#12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x724954)
#13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x724954)
#14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x72434a)
#15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x72434a)
#16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x72434a)
#17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x72434a)
#18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x72434a)
#19 pthread_once <null> (libtsan.so.0+0x4457c)
#20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72532b)
#21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x72532b)
#22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x174568d)
#23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x174568d)
#24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x174568d)
#25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x174568d)
#26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x1748040)
#27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x1748040)
#28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x1748040)
#29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x1748040)
#30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x1748040)
#31 <null> <null> (libstdc++.so.6+0xdcac2)
...
SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:3077 in dw_expand_symtabs_matching_file_matcher(dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>)
...
The race happens when issuing the "file $exec" command.
The race is between:
- a worker thread writing the index cache, and in the process reading
dwarf2_per_cu_data::is_debug_type, and
- the main thread writing to dwarf2_per_cu_data::mark.
The two bitfields dwarf2_per_cu_data::mark and
dwarf2_per_cu_data::is_debug_type share the same bitfield container.
Fix this by making dwarf2_per_cu_data::mark a packed<unsigned int, 1>.
Tested on x86_64-linux.
PR symtab/30718
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30718
MaryBennett
pushed a commit
that referenced
this pull request
Oct 5, 2023
…g_types}
With gdb build with -fsanitize=thread, and the exec from test-case
gdb.base/index-cache.exp, I run into:
...
$ rm -f ~/.cache/gdb/*; \
gdb -q -batch -iex "set index-cache enabled on" index-cache \
-ex "print foobar"
...
WARNING: ThreadSanitizer: data race (pid=25018)
Write of size 1 at 0x7b200000410d by main thread:
#0 dw2_get_file_names_reader gdb/dwarf2/read.c:2033 (gdb+0x7ab023)
#1 dw2_get_file_names gdb/dwarf2/read.c:2130 (gdb+0x7ab023)
#2 dw_expand_symtabs_matching_file_matcher(dwarf2_per_objfile*, gdb::function_view<bool (char const*, bool)>) gdb/dwarf2/read.c:3105 (gdb+0x7ac6e9)
#3 cooked_index_functions::expand_symtabs_matching(objfile*, gdb::function_view<bool (char const*, bool)>, lookup_name_info const*, gdb::function_view<bool (char const*)>, gdb::function_view<bool (compunit_symtab*)>, enum_flags<block_search_flag_values>, domain_enum, search_domain) gdb/dwarf2/read.c:16812 (gdb+0x7d040f)
#4 objfile::map_symtabs_matching_filename(char const*, char const*, gdb::function_view<bool (symtab*)>) gdb/symfile-debug.c:219 (gdb+0xda5b6e)
#5 iterate_over_symtabs(char const*, gdb::function_view<bool (symtab*)>) gdb/symtab.c:648 (gdb+0xdc441d)
#6 lookup_symtab(char const*) gdb/symtab.c:662 (gdb+0xdc4522)
#7 classify_name gdb/c-exp.y:3083 (gdb+0x61afec)
#8 c_yylex gdb/c-exp.y:3251 (gdb+0x61dd13)
#9 c_yyparse() build/gdb/c-exp.c.tmp:1988 (gdb+0x61f07e)
#10 c_parse(parser_state*) gdb/c-exp.y:3417 (gdb+0x62d864)
#11 language_defn::parser(parser_state*) const gdb/language.c:598 (gdb+0x977245)
#12 parse_exp_in_context gdb/parse.c:414 (gdb+0xb10b1b)
#13 parse_expression(char const*, innermost_block_tracker*, enum_flags<parser_flag>) gdb/parse.c:462 (gdb+0xb1112e)
#14 process_print_command_args gdb/printcmd.c:1321 (gdb+0xb4bf8c)
#15 print_command_1 gdb/printcmd.c:1335 (gdb+0xb4caaa)
#16 print_command gdb/printcmd.c:1468 (gdb+0xb4cdda)
#17 do_simple_func gdb/cli/cli-decode.c:95 (gdb+0x65b078)
#18 cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735 (gdb+0x65ed53)
#19 execute_command(char const*, int) gdb/top.c:575 (gdb+0xe3a7ea)
#20 catch_command_errors gdb/main.c:518 (gdb+0xa183fd)
#21 execute_cmdargs gdb/main.c:617 (gdb+0xa185bf)
#22 captured_main_1 gdb/main.c:1289 (gdb+0xa1aad8)
#23 captured_main gdb/main.c:1310 (gdb+0xa1b9da)
#24 gdb_main(captured_main_args*) gdb/main.c:1339 (gdb+0xa1b9da)
#25 main gdb/gdb.c:39 (gdb+0x42506a)
Previous read of size 1 at 0x7b200000410d by thread T2:
#0 write_gdbindex gdb/dwarf2/index-write.c:1214 (gdb+0x75bb30)
#1 write_dwarf_index(dwarf2_per_bfd*, char const*, char const*, char const*, dw_index_kind) gdb/dwarf2/index-write.c:1469 (gdb+0x75f803)
#2 index_cache::store(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/index-cache.c:173 (gdb+0x755a36)
#3 cooked_index::maybe_write_index(dwarf2_per_bfd*, index_cache_store_context const&) gdb/dwarf2/cooked-index.c:642 (gdb+0x71c96d)
#4 operator() gdb/dwarf2/cooked-index.c:471 (gdb+0x71c96d)
#5 _M_invoke /usr/include/c++/7/bits/std_function.h:316 (gdb+0x71c96d)
#6 std::function<void ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x72a57c)
#7 void std::__invoke_impl<void, std::function<void ()>&>(std::__invoke_other, std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:60 (gdb+0x72a5db)
#8 std::__invoke_result<std::function<void ()>&>::type std::__invoke<std::function<void ()>&>(std::function<void ()>&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x72a5db)
#9 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}::operator()() const /usr/include/c++/7/future:1421 (gdb+0x72a5db)
#10 std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void>::operator()() const /usr/include/c++/7/future:1362 (gdb+0x72a5db)
#11 std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run()::{lambda()#1}, void> >::_M_invoke(std::_Any_data const&) /usr/include/c++/7/bits/std_function.h:302 (gdb+0x72a5db)
#12 std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>::operator()() const /usr/include/c++/7/bits/std_function.h:706 (gdb+0x724954)
#13 std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*) /usr/include/c++/7/future:561 (gdb+0x724954)
#14 void std::__invoke_impl<void, void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::__invoke_memfun_deref, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x72434a)
#15 std::__invoke_result<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>::type std::__invoke<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x72434a)
#16 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#1}::operator()() const /usr/include/c++/7/mutex:672 (gdb+0x72434a)
#17 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::operator()() const /usr/include/c++/7/mutex:677 (gdb+0x72434a)
#18 std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&)::{lambda()#2}::_FUN() /usr/include/c++/7/mutex:677 (gdb+0x72434a)
#19 pthread_once <null> (libtsan.so.0+0x4457c)
#20 __gthread_once /usr/include/c++/7/x86_64-suse-linux/bits/gthr-default.h:699 (gdb+0x72532b)
#21 void std::call_once<void (std::__future_base::_State_baseV2::*)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*>(std::once_flag&, void (std::__future_base::_State_baseV2::*&&)(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*), std::__future_base::_State_baseV2*&&, std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*&&, bool*&&) /usr/include/c++/7/mutex:684 (gdb+0x72532b)
#22 std::__future_base::_State_baseV2::_M_set_result(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>, bool) /usr/include/c++/7/future:401 (gdb+0x174570d)
#23 std::__future_base::_Task_state<std::function<void ()>, std::allocator<int>, void ()>::_M_run() /usr/include/c++/7/future:1423 (gdb+0x174570d)
#24 std::packaged_task<void ()>::operator()() /usr/include/c++/7/future:1556 (gdb+0x174570d)
#25 gdb::thread_pool::thread_function() gdbsupport/thread-pool.cc:242 (gdb+0x174570d)
#26 void std::__invoke_impl<void, void (gdb::thread_pool::*)(), gdb::thread_pool*>(std::__invoke_memfun_deref, void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:73 (gdb+0x17480c0)
#27 std::__invoke_result<void (gdb::thread_pool::*)(), gdb::thread_pool*>::type std::__invoke<void (gdb::thread_pool::*)(), gdb::thread_pool*>(void (gdb::thread_pool::*&&)(), gdb::thread_pool*&&) /usr/include/c++/7/bits/invoke.h:95 (gdb+0x17480c0)
#28 decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) /usr/include/c++/7/thread:234 (gdb+0x17480c0)
#29 std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> >::operator()() /usr/include/c++/7/thread:243 (gdb+0x17480c0)
#30 std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (gdb::thread_pool::*)(), gdb::thread_pool*> > >::_M_run() /usr/include/c++/7/thread:186 (gdb+0x17480c0)
#31 <null> <null> (libstdc++.so.6+0xdcac2)
...
SUMMARY: ThreadSanitizer: data race gdb/dwarf2/read.c:2033 in dw2_get_file_names_reader
...
The race happens when issuing the "file $exec" command.
The race is between:
- a worker thread writing the index cache, and in the process reading
dwarf2_per_cu_data::is_debug_type, and
- the main thread writing to dwarf2_per_cu_data::files_read.
The two bitfields dwarf2_per_cu_data::files_read and
dwarf2_per_cu_data::is_debug_type share the same bitfield container.
Fix this by making dwarf2_per_cu_data::files_read a packed<bool, 1>.
Tested on x86_64-linux.
PR symtab/30718
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30718
MaryBennett
pushed a commit
to MaryBennett/corev-binutils-gdb
that referenced
this pull request
Nov 6, 2023
It was pointed out on the mailing list that a recently added test (gdb.python/py-progspace-events.exp) was failing when run with the native-extended-gdbserver board. This test was added with this commit: commit 59912fb Date: Tue Sep 19 11:45:36 2023 +0100 gdb: add Python events for program space addition and removal It turns out though that the test is failing due to a existing bug in GDB, the new test just exposes the problem. Additionally, the failure really doesn't even rely on the new functionality added in the above commit. I reduced the test to a simple set of steps that reproduced the failure and tested against GDB 13, and the test passes; so the bug was introduced since then. In fact, the bug was introduced with this commit: commit a282736 Date: Fri Sep 8 15:48:16 2023 +0100 gdb: remove final user of the executable_changed observer This commit changed how the per-inferior auxv data cache is managed, specifically, when the cache is cleared, and it is this that leads to the failure. This bug is interesting because it exposes a number of issues with GDB, I'll explain all of the problems I see, though ultimately, I only propose fixing one problem in this commit, which is enough to resolve the crash we are currently seeing. The crash that we are seeing manifests like this: ... [Inferior 2 (process 3970384) exited normally] +inferior 1 [Switching to inferior 1 [process 3970383] (/tmp/build/gdb/testsuite/outputs/gdb.python/py-progspace-events/py-progspace-events)] [Switching to thread 1.1 (Thread 3970383.3970383)] #0 breakpt () at /tmp/build/gdb/testsuite/../../../src/gdb/testsuite/gdb.python/py-progspace-events.c:28 28 { /* Nothing. */ } (gdb) step +step terminate called after throwing an instance of 'gdb_exception_error' Fatal signal: Aborted ... etc ... What's happening is that GDB attempts to refill the auxv cache as a result of the gdbarch_has_shared_address_space call in program_space::~program_space, the backtrace looks like this: #0 0x00007fb4f419a9a5 in raise () from /lib64/libpthread.so.0 #1 0x00000000008b635d in handle_fatal_signal (sig=6) at ../../src/gdb/event-top.c:912 openhwgroup#2 <signal handler called> openhwgroup#3 0x00007fb4f38e3625 in raise () from /lib64/libc.so.6 openhwgroup#4 0x00007fb4f38cc8d9 in abort () from /lib64/libc.so.6 openhwgroup#5 0x00007fb4f3c70756 in __gnu_cxx::__verbose_terminate_handler() [clone .cold] () from /lib64/libstdc++.so.6 openhwgroup#6 0x00007fb4f3c7c6dc in __cxxabiv1::__terminate(void (*)()) () from /lib64/libstdc++.so.6 openhwgroup#7 0x00007fb4f3c7b6e9 in __cxa_call_terminate () from /lib64/libstdc++.so.6 openhwgroup#8 0x00007fb4f3c7c094 in __gxx_personality_v0 () from /lib64/libstdc++.so.6 openhwgroup#9 0x00007fb4f3a80c63 in _Unwind_RaiseException_Phase2 () from /lib64/libgcc_s.so.1 openhwgroup#10 0x00007fb4f3a8154e in _Unwind_Resume () from /lib64/libgcc_s.so.1 openhwgroup#11 0x0000000000e8832d in target_read_alloc_1<unsigned char> (ops=0x408a3a0, object=TARGET_OBJECT_AUXV, annex=0x0) at ../../src/gdb/target.c:2266 openhwgroup#12 0x0000000000e73dea in target_read_alloc (ops=0x408a3a0, object=TARGET_OBJECT_AUXV, annex=0x0) at ../../src/gdb/target.c:2315 openhwgroup#13 0x000000000058248c in target_read_auxv_raw (ops=0x408a3a0) at ../../src/gdb/auxv.c:379 openhwgroup#14 0x000000000058243d in target_read_auxv () at ../../src/gdb/auxv.c:368 openhwgroup#15 0x000000000058255c in target_auxv_search (match=0x0, valp=0x7ffdee17c598) at ../../src/gdb/auxv.c:415 openhwgroup#16 0x0000000000a464bb in linux_is_uclinux () at ../../src/gdb/linux-tdep.c:433 openhwgroup#17 0x0000000000a464f6 in linux_has_shared_address_space (gdbarch=0x409a2d0) at ../../src/gdb/linux-tdep.c:440 openhwgroup#18 0x0000000000510eae in gdbarch_has_shared_address_space (gdbarch=0x409a2d0) at ../../src/gdb/gdbarch.c:4889 openhwgroup#19 0x0000000000bc7558 in program_space::~program_space (this=0x4544aa0, __in_chrg=<optimized out>) at ../../src/gdb/progspace.c:124 openhwgroup#20 0x00000000009b245d in delete_inferior (inf=0x47b3de0) at ../../src/gdb/inferior.c:290 openhwgroup#21 0x00000000009b2c10 in prune_inferiors () at ../../src/gdb/inferior.c:480 openhwgroup#22 0x00000000009c5e3e in fetch_inferior_event () at ../../src/gdb/infrun.c:4558 openhwgroup#23 0x000000000099b4dc in inferior_event_handler (event_type=INF_REG_EVENT) at ../../src/gdb/inf-loop.c:42 openhwgroup#24 0x0000000000cbc64f in remote_async_serial_handler (scb=0x4090a30, context=0x408a6b0) at ../../src/gdb/remote.c:14859 openhwgroup#25 0x0000000000d83d3a in run_async_handler_and_reschedule (scb=0x4090a30) at ../../src/gdb/ser-base.c:138 openhwgroup#26 0x0000000000d83e1f in fd_event (error=0, context=0x4090a30) at ../../src/gdb/ser-base.c:189 So this is problem #1, if we throw an exception while deleting a program_space then this is not caught, and is going to crash GDB. Problem openhwgroup#2 becomes evident when we ask why GDB is throwing an error in this case; the error is thrown because the remote target, operating in non-async mode, can't read the auxv data while an inferior is running and GDB is waiting for a stop reply. The problem here then, is why does GDB get into a position where it tries to interact with the remote target in this way, at this time? The problem is caused by the prune_inferiors call which can be seen in the above backtrace. In prune_inferiors we check if the inferior is deletable, and if it is, we delete it. The problem is, I think, we should also check if the target is currently in a state that would allow us to delete the inferior. We don't currently have such a check available, we'd need to add one, but for the remote target, this would return false if the remote is in async mode and the remote is currently waiting for a stop reply. With this change in place GDB would defer deleting the inferior until the remote target has stopped, at which point GDB would be able to refill the auxv cache successfully. And then, problem openhwgroup#3 becomes evident when we ask why GDB is needing to refill the auxv cache now when it didn't need to for GDB 13. This is where the second commit mentioned above (a282736) comes in. Prior to this commit, the auxv cache was cleared by the executable_changed observer, while after that commit the auxv cache was cleared by the new_objfile observer -- but only when the new_objfile observer is used in the special mode that actually means that all objfiles have been unloaded (I know, the overloading of the new_objfile observer is horrible, and unnecessary, but it's not really important for this bug). The difference arises because the new_objfile observer is triggered from clear_symtab_users, which in turn is called from program_space::~program_space. The new_objfile observer for auxv does this: static void auxv_new_objfile_observer (struct objfile *objfile) { if (objfile == nullptr) invalidate_auxv_cache_inf (current_inferior ()); } That is, when all the objfiles are unloaded, we clear the auxv cache for the current inferior. The problem is, then when we look at the prune_inferiors -> delete_inferior -> ~program_space path, we see that the current inferior is not going to be an inferior that exists within the program_space being deleted; delete_inferior removes the deleted inferior from the global inferior list, and then only deletes the program_space if program_space::empty() returns true, which is only the case if the current inferior isn't within the program_space to delete, and no other inferior exists within that program_space either. What this means is that when the new_objfile observer is called we can't rely on the current inferior having any relationship with the program space in which the objfiles were removed. This was an error in the commit a282736, the only thing we can rely on is the current program space. As a result of this mistake, after commit a282736, GDB was sometimes clearing the auxv cache for a random inferior. In the native target case this was harmless as we can always refill the cache when needed, but in the remote target case, if we need to refill the cache when the remote target is executing, then we get the crash we observed. And additionally, if we think about this a little more, we see that commit a282736 made another mistake. When all the objfiles are removed, they are removed from a program_space, a program_space might contain multiple inferiors, so surely, we should clear the auxv cache for all of the matching inferiors? Given these two insights, that the current_inferior is not relevant, only the current_program_space, and that we should be clearing the cache for all inferiors in the current_program_space, we can update auxv_new_objfile_observer to: if (objfile == nullptr) { for (inferior *inf : all_inferiors ()) { if (inf->pspace == current_program_space) invalidate_auxv_cache_inf (inf); } } With this change we now correctly clear the auxv cache for the correct inferiors, and GDB no longer needs to refill the cache at an inconvenient time, this avoids the crash we were seeing. And finally, we reach problem openhwgroup#4. Inspired by the observation that using the current_inferior from within the ~program_space function was not correct, I added some debug to see if current_inferior() was called anywhere else (below ~program_space), and the answer is yes, it's called a often. Mostly the culprit is GDB doing: current_inferior ()->top_target ()-> .... But I think all of these calls are most likely doing the wrong thing, and only work because the top target in all these cases is shared between all inferiors, e.g. it's the native target, or the remote target for all inferiors. But if we had a truly multi-connection setup, then we might start to see odd behaviour. Problem #1 I'm just ignoring for now, I guess at some point we might run into this again, and then we'd need to solve this. But in this case I wasn't sure what a "good" solution would look like. We need the auxv data in order to implement the linux_is_uclinux() function. If we can't get the auxv data then what should we do, assume yes, or assume no? The right answer would probably be to propagate the error back up the stack, but then we reach ~program_space, and throwing exceptions from a destructor is problematic, so we'd need to catch and deal at this point. The linux_is_uclinux() call is made from within gdbarch_has_shared_address_space(), which is used like: if (!gdbarch_has_shared_address_space (target_gdbarch ())) delete this->aspace; So, we would have to choose; delete the address space or not. If we delete it on error, then we might delete an address space that is shared within another program space. If we don't delete the address space, then we might leak it. Neither choice is great. A better solution might be to have the address spaces be reference counted, then we could remove the gdbarch_has_shared_address_space call completely, and just rely on the reference count to auto-delete the address space when appropriate. The solution for problem openhwgroup#2 I already hinted at above, we should have a new target_can_delete_inferiors() call, which should be called from prune_inferiors, this would prevent GDB from trying to delete inferiors when a (remote) target is in a state where we know it can't delete the inferior. Deleting an inferior often (always?) requires sending packets to the remote, and if the remote is waiting for a stop reply then this will never work, so the pruning should be deferred in this case. The solution for problem openhwgroup#3 is included in this commit. And, for problem openhwgroup#4, I'm not sure what the right solution is. Maybe delete_inferior should ensure the inferior to be deleted is in place when ~program_space is called? But that seems a little weird, as the current inferior would, in theory, still be using the current program_space... Anyway, after this commit, the gdb.python/py-progspace-events.exp test now passes when run with the native-extended-remote board. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30935 Approved-By: Simon Marchi <simon.marchi@efficios.com> Change-Id: I41f0e6e2d7ecc1e5e55ec170f37acd4052f46eaf
Slattz
pushed a commit
to Slattz/corev-binutils-gdb
that referenced
this pull request
Mar 18, 2024
When running test-case gdb.dap/eof.exp, it occasionally coredumps. The thread triggering the coredump is: ... #0 0x0000ffff42bb2280 in __pthread_kill_implementation () from /lib64/libc.so.6 openhwgroup#1 0x0000ffff42b65800 [PAC] in raise () from /lib64/libc.so.6 openhwgroup#2 0x00000000007b03e8 [PAC] in handle_fatal_signal (sig=11) at gdb/event-top.c:926 openhwgroup#3 0x00000000007b0470 in handle_sigsegv (sig=11) at gdb/event-top.c:976 openhwgroup#4 <signal handler called> openhwgroup#5 0x0000000000606080 in cli_ui_out::do_message (this=0xffff2f7ed728, style=..., format=0xffff0c002af1 "%s", args=...) at gdb/cli-out.c:232 openhwgroup#6 0x0000000000ce6358 in ui_out::call_do_message (this=0xffff2f7ed728, style=..., format=0xffff0c002af1 "%s") at gdb/ui-out.c:584 openhwgroup#7 0x0000000000ce6610 in ui_out::vmessage (this=0xffff2f7ed728, in_style=..., format=0x16f93ea "", args=...) at gdb/ui-out.c:621 openhwgroup#8 0x0000000000ce3a9c in ui_file::vprintf (this=0xfffffbea1b18, ...) at gdb/ui-file.c:74 openhwgroup#9 0x0000000000d2b148 in gdb_vprintf (stream=0xfffffbea1b18, format=0x16f93e8 "%s", args=...) at gdb/utils.c:1898 openhwgroup#10 0x0000000000d2b23c in gdb_printf (stream=0xfffffbea1b18, format=0x16f93e8 "%s") at gdb/utils.c:1913 openhwgroup#11 0x0000000000ab5208 in gdbpy_write (self=0x33fe35d0, args=0x342ec280, kw=0x345c08b0) at gdb/python/python.c:1464 openhwgroup#12 0x0000ffff434acedc in cfunction_call () from /lib64/libpython3.12.so.1.0 openhwgroup#13 0x0000ffff4347c500 [PAC] in _PyObject_MakeTpCall () from /lib64/libpython3.12.so.1.0 openhwgroup#14 0x0000ffff43488b64 [PAC] in _PyEval_EvalFrameDefault () from /lib64/libpython3.12.so.1.0 openhwgroup#15 0x0000ffff434d8cd0 [PAC] in method_vectorcall () from /lib64/libpython3.12.so.1.0 openhwgroup#16 0x0000ffff434b9824 [PAC] in PyObject_CallOneArg () from /lib64/libpython3.12.so.1.0 openhwgroup#17 0x0000ffff43557674 [PAC] in PyFile_WriteObject () from /lib64/libpython3.12.so.1.0 openhwgroup#18 0x0000ffff435577a0 [PAC] in PyFile_WriteString () from /lib64/libpython3.12.so.1.0 openhwgroup#19 0x0000ffff43465354 [PAC] in thread_excepthook () from /lib64/libpython3.12.so.1.0 openhwgroup#20 0x0000ffff434ac6e0 [PAC] in cfunction_vectorcall_O () from /lib64/libpython3.12.so.1.0 openhwgroup#21 0x0000ffff434a32d8 [PAC] in PyObject_Vectorcall () from /lib64/libpython3.12.so.1.0 openhwgroup#22 0x0000ffff43488b64 [PAC] in _PyEval_EvalFrameDefault () from /lib64/libpython3.12.so.1.0 openhwgroup#23 0x0000ffff434d8d88 [PAC] in method_vectorcall () from /lib64/libpython3.12.so.1.0 openhwgroup#24 0x0000ffff435e0ef4 [PAC] in thread_run () from /lib64/libpython3.12.so.1.0 openhwgroup#25 0x0000ffff43591ec0 [PAC] in pythread_wrapper () from /lib64/libpython3.12.so.1.0 openhwgroup#26 0x0000ffff42bb0584 [PAC] in start_thread () from /lib64/libc.so.6 openhwgroup#27 0x0000ffff42c1fd4c [PAC] in thread_start () from /lib64/libc.so.6 ... The direct cause for the coredump seems to be that cli_ui_out::do_message is trying to write to a stream variable which does not look sound: ... (gdb) p *stream $8 = {_vptr.ui_file = 0x0, m_applied_style = {m_foreground = {m_simple = true, { m_value = 0, {m_red = 0 '\000', m_green = 0 '\000', m_blue = 0 '\000'}}}, m_background = {m_simple = 32, {m_value = 65535, {m_red = 255 '\377', m_green = 255 '\377', m_blue = 0 '\000'}}}, m_intensity = (unknown: 0x438fe710), m_reverse = 255}} ... The string that is being printed is: ... (gdb) p str $9 = "Exception in thread " ... so AFAICT this is a DAP thread running into an exception and trying to print it. If we look at the state of gdb's main thread, we have: ... #0 0x0000ffff42bac914 in __futex_abstimed_wait_cancelable64 () from /lib64/libc.so.6 openhwgroup#1 0x0000ffff42bafb44 [PAC] in pthread_cond_timedwait@@GLIBC_2.17 () from /lib64/libc.so.6 openhwgroup#2 0x0000ffff43466e9c [PAC] in take_gil () from /lib64/libpython3.12.so.1.0 openhwgroup#3 0x0000ffff43484fe0 [PAC] in PyEval_RestoreThread () from /lib64/libpython3.12.so.1.0 openhwgroup#4 0x0000000000ab8698 [PAC] in gdbpy_allow_threads::~gdbpy_allow_threads ( this=0xfffffbea1cf8, __in_chrg=<optimized out>) at gdb/python/python-internal.h:769 openhwgroup#5 0x0000000000ab2fec in execute_gdb_command (self=0x33fe35d0, args=0x34297b60, kw=0x34553d20) at gdb/python/python.c:681 openhwgroup#6 0x0000ffff434acedc in cfunction_call () from /lib64/libpython3.12.so.1.0 openhwgroup#7 0x0000ffff4347c500 [PAC] in _PyObject_MakeTpCall () from /lib64/libpython3.12.so.1.0 openhwgroup#8 0x0000ffff43488b64 [PAC] in _PyEval_EvalFrameDefault () from /lib64/libpython3.12.so.1.0 openhwgroup#9 0x0000ffff4353bce8 [PAC] in _PyObject_VectorcallTstate.lto_priv.3 () from /lib64/libpython3.12.so.1.0 openhwgroup#10 0x0000000000ab87fc [PAC] in gdbpy_event::operator() (this=0xffff14005900) at gdb/python/python.c:1061 openhwgroup#11 0x0000000000ab93e8 in std::__invoke_impl<void, gdbpy_event&> (__f=...) at /usr/include/c++/13/bits/invoke.h:61 openhwgroup#12 0x0000000000ab9204 in std::__invoke_r<void, gdbpy_event&> (__fn=...) at /usr/include/c++/13/bits/invoke.h:111 openhwgroup#13 0x0000000000ab8e90 in std::_Function_handler<..>::_M_invoke(...) (...) at /usr/include/c++/13/bits/std_function.h:290 openhwgroup#14 0x000000000062e0d0 in std::function<void ()>::operator()() const ( this=0xffff14005830) at /usr/include/c++/13/bits/std_function.h:591 openhwgroup#15 0x0000000000b67f14 in run_events (error=0, client_data=0x0) at gdb/run-on-main-thread.c:76 openhwgroup#16 0x000000000157e290 in handle_file_event (file_ptr=0x33dae3a0, ready_mask=1) at gdbsupport/event-loop.cc:573 openhwgroup#17 0x000000000157e760 in gdb_wait_for_event (block=1) at gdbsupport/event-loop.cc:694 openhwgroup#18 0x000000000157d464 in gdb_do_one_event (mstimeout=-1) at gdbsupport/event-loop.cc:264 openhwgroup#19 0x0000000000943a84 in start_event_loop () at gdb/main.c:401 openhwgroup#20 0x0000000000943bfc in captured_command_loop () at gdb/main.c:465 openhwgroup#21 0x000000000094567c in captured_main (data=0xfffffbea23e8) at gdb/main.c:1335 openhwgroup#22 0x0000000000945700 in gdb_main (args=0xfffffbea23e8) at gdb/main.c:1354 openhwgroup#23 0x0000000000423ab4 in main (argc=14, argv=0xfffffbea2578) at gdb/gdb.c:39 ... AFAIU, there's a race between the two threads on gdb_stderr: - the DAP thread samples the gdb_stderr value, and uses it a bit later to print to - the gdb main thread changes the gdb_stderr value forth and back, using a temporary value for string capture purposes The non-sound stream value is caused by gdb_stderr being sampled while pointing to a str_file object, and used once the str_file object is already destroyed. The error here is that the DAP thread attempts to print to gdb_stderr. Fix this by adding a thread_wrapper that: - catches all exceptions and logs them to dap.log, and - while we're at it, logs when exiting and using the thread_wrapper for each DAP thread. Tested on aarch64-linux. Approved-By: Tom Tromey <tom@tromey.com>
Slattz
pushed a commit
to Slattz/corev-binutils-gdb
that referenced
this pull request
Mar 18, 2024
When running test-case gdb.dap/eof.exp, we're likely to get a coredump due to a segfault in new_threadstate. At the point of the core dump, the gdb main thread looks like: ... (gdb) bt #0 0x0000fffee30d2280 in __pthread_kill_implementation () from /lib64/libc.so.6 openhwgroup#1 0x0000fffee3085800 [PAC] in raise () from /lib64/libc.so.6 openhwgroup#2 0x00000000007b03e8 [PAC] in handle_fatal_signal (sig=11) at gdb/event-top.c:926 openhwgroup#3 0x00000000007b0470 in handle_sigsegv (sig=11) at gdb/event-top.c:976 openhwgroup#4 <signal handler called> openhwgroup#5 0x0000fffee3a4db14 in new_threadstate () from /lib64/libpython3.12.so.1.0 openhwgroup#6 0x0000fffee3ab0548 [PAC] in PyGILState_Ensure () from /lib64/libpython3.12.so.1.0 openhwgroup#7 0x0000000000a6d034 [PAC] in gdbpy_gil::gdbpy_gil (this=0xffffcb279738) at gdb/python/python-internal.h:787 openhwgroup#8 0x0000000000ab87ac in gdbpy_event::~gdbpy_event (this=0xfffea8001ee0, __in_chrg=<optimized out>) at gdb/python/python.c:1051 openhwgroup#9 0x0000000000ab9460 in std::_Function_base::_Base_manager<...>::_M_destroy (__victim=...) at /usr/include/c++/13/bits/std_function.h:175 openhwgroup#10 0x0000000000ab92dc in std::_Function_base::_Base_manager<...>::_M_manager (__dest=..., __source=..., __op=std::__destroy_functor) at /usr/include/c++/13/bits/std_function.h:203 openhwgroup#11 0x0000000000ab8f14 in std::_Function_handler<...>::_M_manager(...) (...) at /usr/include/c++/13/bits/std_function.h:282 openhwgroup#12 0x000000000042dd9c in std::_Function_base::~_Function_base (this=0xfffea8001c10, __in_chrg=<optimized out>) at /usr/include/c++/13/bits/std_function.h:244 openhwgroup#13 0x000000000042e654 in std::function<void ()>::~function() (this=0xfffea8001c10, __in_chrg=<optimized out>) at /usr/include/c++/13/bits/std_function.h:334 openhwgroup#14 0x0000000000b68e60 in std::_Destroy<std::function<void ()> >(...) (...) at /usr/include/c++/13/bits/stl_construct.h:151 openhwgroup#15 0x0000000000b68cd0 in std::_Destroy_aux<false>::__destroy<...>(...) (...) at /usr/include/c++/13/bits/stl_construct.h:163 openhwgroup#16 0x0000000000b689d8 in std::_Destroy<...>(...) (...) at /usr/include/c++/13/bits/stl_construct.h:196 openhwgroup#17 0x0000000000b68414 in std::_Destroy<...>(...) (...) at /usr/include/c++/13/bits/alloc_traits.h:948 openhwgroup#18 std::vector<...>::~vector() (this=0x2a183c8 <runnables>) at /usr/include/c++/13/bits/stl_vector.h:732 openhwgroup#19 0x0000fffee3088370 in __run_exit_handlers () from /lib64/libc.so.6 openhwgroup#20 0x0000fffee3088450 [PAC] in exit () from /lib64/libc.so.6 openhwgroup#21 0x0000000000c95600 [PAC] in quit_force (exit_arg=0x0, from_tty=0) at gdb/top.c:1822 openhwgroup#22 0x0000000000609140 in quit_command (args=0x0, from_tty=0) at gdb/cli/cli-cmds.c:508 openhwgroup#23 0x0000000000c926a4 in quit_cover () at gdb/top.c:300 openhwgroup#24 0x00000000007b09d4 in async_disconnect (arg=0x0) at gdb/event-top.c:1230 openhwgroup#25 0x0000000000548acc in invoke_async_signal_handlers () at gdb/async-event.c:234 openhwgroup#26 0x000000000157d2d4 in gdb_do_one_event (mstimeout=-1) at gdbsupport/event-loop.cc:199 openhwgroup#27 0x0000000000943a84 in start_event_loop () at gdb/main.c:401 openhwgroup#28 0x0000000000943bfc in captured_command_loop () at gdb/main.c:465 openhwgroup#29 0x000000000094567c in captured_main (data=0xffffcb279d08) at gdb/main.c:1335 openhwgroup#30 0x0000000000945700 in gdb_main (args=0xffffcb279d08) at gdb/main.c:1354 openhwgroup#31 0x0000000000423ab4 in main (argc=14, argv=0xffffcb279e98) at gdb/gdb.c:39 ... The direct cause of the segfault is calling PyGILState_Ensure after calling Py_Finalize. AFAICT the problem is a race between the gdb main thread and DAP's JSON writer thread. On one side, we have the following events: - DAP's JSON reader thread reads an EOF, and lets DAP's main thread known by writing None into read_queue - DAP's main thread lets DAP's JSON writer thread known by writing None into write_queue - DAP's JSON writer thread sees the None in its queue, and calls send_gdb("quit") - a corresponding gdbpy_event is deposited in the runnables vector, to be run by the gdb main thread On the other side, we have the following events: - the gdb main thread receives a SIGHUP - the corresponding handler calls quit_force, which calls do_final_cleanups - one of the final cleanups is finalize_python, which calls Py_Finalize - quit_force calls exit, which triggers the exit handlers - one of the exit handlers is the destructor of the runnables vector - destruction of the vector triggers destruction of the remaining element - the remaining element is a gdbpy_event, and the destructor (indirectly) calls PyGILState_Ensure It's good to note that both events (EOF and SIGHUP) are caused by this line in the test-case: ... catch "close -i $gdb_spawn_id" ... where "expect close" closes the stdin and stdout file descriptors, which causes the SIGHUP to be send. So, for the system I'm running this on, the send_gdb("quit") is actually not needed. I'm not sure if we support any systems where it's actually needed. Fix this by removing the send_gdb("quit"). Tested on aarch64-linux. PR dap/31306 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31306
Slattz
pushed a commit
to Slattz/corev-binutils-gdb
that referenced
this pull request
Mar 18, 2024
When building gdb with -O0 -fsanitize=address, and running test-case
gdb.ada/uninitialized_vars.exp, I run into:
...
(gdb) info locals
a = 0
z = (a => 1, b => false, c => 2.0)
=================================================================
==66372==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x602000097f58 at pc 0xffff52c0da1c bp 0xffffc90a1d40 sp 0xffffc90a1d80
READ of size 4 at 0x602000097f58 thread T0
#0 0xffff52c0da18 in memmove (/lib64/libasan.so.8+0x6da18)
openhwgroup#1 0xbcab24 in unsigned char* std::__copy_move_backward<false, true, std::random_access_iterator_tag>::__copy_move_b<unsigned char const, unsigned char>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:748
openhwgroup#2 0xbc9bf4 in unsigned char* std::__copy_move_backward_a2<false, unsigned char const*, unsigned char*>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:769
openhwgroup#3 0xbc898c in unsigned char* std::__copy_move_backward_a1<false, unsigned char const*, unsigned char*>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:778
openhwgroup#4 0xbc715c in unsigned char* std::__copy_move_backward_a<false, unsigned char const*, unsigned char*>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:807
openhwgroup#5 0xbc4e6c in unsigned char* std::copy_backward<unsigned char const*, unsigned char*>(unsigned char const*, unsigned char const*, unsigned char*) /usr/include/c++/13/bits/stl_algobase.h:867
openhwgroup#6 0xbc2934 in void gdb::copy<unsigned char const, unsigned char>(gdb::array_view<unsigned char const>, gdb::array_view<unsigned char>) gdb/../gdbsupport/array-view.h:223
openhwgroup#7 0x20e0100 in value::contents_copy_raw(value*, long, long, long) gdb/value.c:1239
openhwgroup#8 0x20e9830 in value::primitive_field(long, int, type*) gdb/value.c:3078
openhwgroup#9 0x20e98f8 in value_field(value*, int) gdb/value.c:3095
openhwgroup#10 0xcafd64 in print_field_values gdb/ada-valprint.c:658
openhwgroup#11 0xcb0fa0 in ada_val_print_struct_union gdb/ada-valprint.c:857
openhwgroup#12 0xcb1bb4 in ada_value_print_inner(value*, ui_file*, int, value_print_options const*) gdb/ada-valprint.c:1042
openhwgroup#13 0xc66e04 in ada_language::value_print_inner(value*, ui_file*, int, value_print_options const*) const (/home/vries/gdb/build/gdb/gdb+0xc66e04)
openhwgroup#14 0x20ca1e8 in common_val_print(value*, ui_file*, int, value_print_options const*, language_defn const*) gdb/valprint.c:1092
openhwgroup#15 0x20caabc in common_val_print_checked(value*, ui_file*, int, value_print_options const*, language_defn const*) gdb/valprint.c:1184
openhwgroup#16 0x196c524 in print_variable_and_value(char const*, symbol*, frame_info_ptr, ui_file*, int) gdb/printcmd.c:2355
openhwgroup#17 0x1d99ca0 in print_variable_and_value_data::operator()(char const*, symbol*) gdb/stack.c:2308
openhwgroup#18 0x1dabca0 in gdb::function_view<void (char const*, symbol*)>::bind<print_variable_and_value_data>(print_variable_and_value_data&)::{lambda(gdb::fv_detail::erased_callable, char const*, symbol*)openhwgroup#1}::operator()(gdb::fv_detail::erased_callable, char const*, symbol*) const gdb/../gdbsupport/function-view.h:305
openhwgroup#19 0x1dabd14 in gdb::function_view<void (char const*, symbol*)>::bind<print_variable_and_value_data>(print_variable_and_value_data&)::{lambda(gdb::fv_detail::erased_callable, char const*, symbol*)openhwgroup#1}::_FUN(gdb::fv_detail::erased_callable, char const*, symbol*) gdb/../gdbsupport/function-view.h:299
openhwgroup#20 0x1dab34c in gdb::function_view<void (char const*, symbol*)>::operator()(char const*, symbol*) const gdb/../gdbsupport/function-view.h:289
openhwgroup#21 0x1d9963c in iterate_over_block_locals gdb/stack.c:2240
openhwgroup#22 0x1d99790 in iterate_over_block_local_vars(block const*, gdb::function_view<void (char const*, symbol*)>) gdb/stack.c:2259
openhwgroup#23 0x1d9a598 in print_frame_local_vars gdb/stack.c:2380
openhwgroup#24 0x1d9afac in info_locals_command(char const*, int) gdb/stack.c:2458
openhwgroup#25 0xfd7b30 in do_simple_func gdb/cli/cli-decode.c:95
openhwgroup#26 0xfe5a2c in cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735
openhwgroup#27 0x1f03790 in execute_command(char const*, int) gdb/top.c:575
openhwgroup#28 0x1384080 in command_handler(char const*) gdb/event-top.c:566
openhwgroup#29 0x1384e2c in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:802
openhwgroup#30 0x1f731e4 in tui_command_line_handler gdb/tui/tui-interp.c:104
openhwgroup#31 0x1382a58 in gdb_rl_callback_handler gdb/event-top.c:259
openhwgroup#32 0x21dbb80 in rl_callback_read_char readline/readline/callback.c:290
openhwgroup#33 0x1382510 in gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195
openhwgroup#34 0x138277c in gdb_rl_callback_read_char_wrapper gdb/event-top.c:234
openhwgroup#35 0x1fe9b40 in stdin_event_handler gdb/ui.c:155
openhwgroup#36 0x35ff1bc in handle_file_event gdbsupport/event-loop.cc:573
openhwgroup#37 0x35ff9d8 in gdb_wait_for_event gdbsupport/event-loop.cc:694
openhwgroup#38 0x35fd284 in gdb_do_one_event(int) gdbsupport/event-loop.cc:264
openhwgroup#39 0x1768080 in start_event_loop gdb/main.c:408
openhwgroup#40 0x17684c4 in captured_command_loop gdb/main.c:472
openhwgroup#41 0x176cfc8 in captured_main gdb/main.c:1342
openhwgroup#42 0x176d088 in gdb_main(captured_main_args*) gdb/main.c:1361
openhwgroup#43 0xb73edc in main gdb/gdb.c:39
openhwgroup#44 0xffff519b09d8 in __libc_start_call_main (/lib64/libc.so.6+0x309d8)
openhwgroup#45 0xffff519b0aac in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x30aac)
openhwgroup#46 0xb73c2c in _start (/home/vries/gdb/build/gdb/gdb+0xb73c2c)
0x602000097f58 is located 0 bytes after 8-byte region [0x602000097f50,0x602000097f58)
allocated by thread T0 here:
#0 0xffff52c65218 in calloc (/lib64/libasan.so.8+0xc5218)
openhwgroup#1 0xcbc278 in xcalloc gdb/alloc.c:97
openhwgroup#2 0x35f21e8 in xzalloc(unsigned long) gdbsupport/common-utils.cc:29
openhwgroup#3 0x20de270 in value::allocate_contents(bool) gdb/value.c:937
openhwgroup#4 0x20edc08 in value::fetch_lazy() gdb/value.c:4033
openhwgroup#5 0x20dadc0 in value::entirely_covered_by_range_vector(std::vector<range, std::allocator<range> > const&) gdb/value.c:229
openhwgroup#6 0xcb2298 in value::entirely_optimized_out() gdb/value.h:560
openhwgroup#7 0x20ca6fc in value_check_printable gdb/valprint.c:1133
openhwgroup#8 0x20caa8c in common_val_print_checked(value*, ui_file*, int, value_print_options const*, language_defn const*) gdb/valprint.c:1182
openhwgroup#9 0x196c524 in print_variable_and_value(char const*, symbol*, frame_info_ptr, ui_file*, int) gdb/printcmd.c:2355
openhwgroup#10 0x1d99ca0 in print_variable_and_value_data::operator()(char const*, symbol*) gdb/stack.c:2308
openhwgroup#11 0x1dabca0 in gdb::function_view<void (char const*, symbol*)>::bind<print_variable_and_value_data>(print_variable_and_value_data&)::{lambda(gdb::fv_detail::erased_callable, char const*, symbol*)openhwgroup#1}::operator()(gdb::fv_detail::erased_callable, char const*, symbol*) const gdb/../gdbsupport/function-view.h:305
openhwgroup#12 0x1dabd14 in gdb::function_view<void (char const*, symbol*)>::bind<print_variable_and_value_data>(print_variable_and_value_data&)::{lambda(gdb::fv_detail::erased_callable, char const*, symbol*)openhwgroup#1}::_FUN(gdb::fv_detail::erased_callable, char const*, symbol*) gdb/../gdbsupport/function-view.h:299
openhwgroup#13 0x1dab34c in gdb::function_view<void (char const*, symbol*)>::operator()(char const*, symbol*) const gdb/../gdbsupport/function-view.h:289
openhwgroup#14 0x1d9963c in iterate_over_block_locals gdb/stack.c:2240
openhwgroup#15 0x1d99790 in iterate_over_block_local_vars(block const*, gdb::function_view<void (char const*, symbol*)>) gdb/stack.c:2259
openhwgroup#16 0x1d9a598 in print_frame_local_vars gdb/stack.c:2380
openhwgroup#17 0x1d9afac in info_locals_command(char const*, int) gdb/stack.c:2458
openhwgroup#18 0xfd7b30 in do_simple_func gdb/cli/cli-decode.c:95
openhwgroup#19 0xfe5a2c in cmd_func(cmd_list_element*, char const*, int) gdb/cli/cli-decode.c:2735
openhwgroup#20 0x1f03790 in execute_command(char const*, int) gdb/top.c:575
openhwgroup#21 0x1384080 in command_handler(char const*) gdb/event-top.c:566
openhwgroup#22 0x1384e2c in command_line_handler(std::unique_ptr<char, gdb::xfree_deleter<char> >&&) gdb/event-top.c:802
openhwgroup#23 0x1f731e4 in tui_command_line_handler gdb/tui/tui-interp.c:104
openhwgroup#24 0x1382a58 in gdb_rl_callback_handler gdb/event-top.c:259
openhwgroup#25 0x21dbb80 in rl_callback_read_char readline/readline/callback.c:290
openhwgroup#26 0x1382510 in gdb_rl_callback_read_char_wrapper_noexcept gdb/event-top.c:195
openhwgroup#27 0x138277c in gdb_rl_callback_read_char_wrapper gdb/event-top.c:234
openhwgroup#28 0x1fe9b40 in stdin_event_handler gdb/ui.c:155
openhwgroup#29 0x35ff1bc in handle_file_event gdbsupport/event-loop.cc:573
SUMMARY: AddressSanitizer: heap-buffer-overflow (/lib64/libasan.so.8+0x6da18) in memmove
...
The error happens when trying to print either variable y or y2:
...
type Variable_Record (A : Boolean := True) is record
case A is
when True =>
B : Integer;
when False =>
C : Float;
D : Integer;
end case;
end record;
Y : Variable_Record := (A => True, B => 1);
Y2 : Variable_Record := (A => False, C => 1.0, D => 2);
...
when the variables are uninitialized.
The error happens only when printing the entire variable:
...
(gdb) p y.a
$2 = 216
(gdb) p y.b
There is no member named b.
(gdb) p y.c
$3 = 9.18340949e-41
(gdb) p y.d
$4 = 1
(gdb) p y
<AddressSanitizer: heap-buffer-overflow>
...
The error happens as follows:
- field a functions as discriminant, choosing either the b, or c+d variant.
- when y.a happens to be set to 216, as above, gdb interprets this as the
variable having the c+d variant (which is why trying to print y.b fails).
- when printing y, gdb allocates a value, copies the bytes into it from the
target, and then prints the value.
- gdb allocates the value using the type size, which is 8. It's 8 because
that's what the DW_AT_byte_size indicates. Note that for valid values of a,
it gives correct results: if a is 0 (c+d variant), size is 12, if a is 1
(b variant), size is 8.
- gdb tries to print field d, which is at an 8 byte offset, and that results
in a out-of-bounds access for the allocated 8-byte value.
Fix this by handling this case in value::contents_copy_raw, such that we have:
...
(gdb) p y
$1 = (a => 24, c => 9.18340949e-41,
d => <error reading variable: access outside bounds of object>)
...
An alternative (additional) fix could be this: in compute_variant_fields_inner
gdb reads the discriminant y.a to decide which variant is active. It would be
nice to detect that the value (y.a == 24) is not a valid Boolean, and give up
on choosing a variant altoghether. However, the situation regarding the
internal type CODE_TYPE_BOOL is currently ambiguous (see PR31282) and it's not
possible to reliably decide what valid values are.
The test-case source file gdb.ada/uninitialized-variable-record/parse.adb is
a reduced version of gdb.ada/uninitialized_vars/parse.adb, so it copies the
copyright years.
Note that the test-case needs gcc-12 or newer, it's unsupported for older gcc
versions. [ So, it would be nice to rewrite it into a dwarf assembly
test-case. ]
The test-case loops over all languages. This is inherited from an earlier
attempt to fix this, which had language-specific fixes (in print_field_values,
cp_print_value_fields, pascal_object_print_value_fields and
f_language::value_print_inner). I've left this in, but I suppose it's not
strictly necessary anymore.
Tested on x86_64-linux.
PR exp/31258
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31258
Slattz
pushed a commit
to Slattz/corev-binutils-gdb
that referenced
this pull request
Mar 18, 2024
From the Python API, we can execute GDB commands via gdb.execute. If the command gives an exception, however, we need to recover the GDB prompt and enable stdin, because the exception does not reach top-level GDB or normal_stop. This was done in commit commit 1ba1ac8 Author: Andrew Burgess <andrew.burgess@embecosm.com> Date: Tue Nov 19 11:17:20 2019 +0000 gdb: Enable stdin on exception in execute_gdb_command with the following code: catch (const gdb_exception &except) { /* If an exception occurred then we won't hit normal_stop (), or have an exception reach the top level of the event loop, which are the two usual places in which stdin would be re-enabled. So, before we convert the exception and continue back in Python, we should re-enable stdin here. */ async_enable_stdin (); GDB_PY_HANDLE_EXCEPTION (except); } In this patch, we explain what happens when we run a GDB command in the context of a synchronous command, e.g. via Python observer notifications. As an example, suppose we have the following objfile event listener, specified in a file named file.py: ~~~ import gdb class MyListener: def __init__(self): gdb.events.new_objfile.connect(self.handle_new_objfile_event) self.processed_objfile = False def handle_new_objfile_event(self, event): if self.processed_objfile: return print("loading " + event.new_objfile.filename) self.processed_objfile = True gdb.execute('add-inferior -no-connection') gdb.execute('inferior 2') gdb.execute('target remote | gdbserver - /tmp/a.out') gdb.execute('inferior 1') the_listener = MyListener() ~~~ Using this Python file, we see the behavior below: $ gdb -q -ex "source file.py" -ex "run" --args a.out Reading symbols from a.out... Starting program: /tmp/a.out loading /lib64/ld-linux-x86-64.so.2 [New inferior 2] Added inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] stdin/stdout redirected Process /tmp/a.out created; pid = 3075406 Remote debugging using stdio Reading /tmp/a.out from remote target... ... [Switching to inferior 1 [process 3075400] (/tmp/a.out)] [Switching to thread 1.1 (process 3075400)] #0 0x00007ffff7fe3290 in ?? () from /lib64/ld-linux-x86-64.so.2 (gdb) [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [Inferior 1 (process 3075400) exited normally] Note how the GDB prompt comes in-between the debugger output. We have this obscure behavior, because the executed command, "target remote", triggers an invocation of `normal_stop` that enables stdin. After that, however, the Python notification context completes and GDB continues with its normal flow of executing the 'run' command. This can be seen in the call stack below: (top-gdb) bt #0 async_enable_stdin () at src/gdb/event-top.c:523 openhwgroup#1 0x00005555561c3acd in normal_stop () at src/gdb/infrun.c:9432 openhwgroup#2 0x00005555561b328e in start_remote (from_tty=0) at src/gdb/infrun.c:3801 openhwgroup#3 0x0000555556441224 in remote_target::start_remote_1 (this=0x5555587882e0, from_tty=0, extended_p=0) at src/gdb/remote.c:5225 openhwgroup#4 0x000055555644166c in remote_target::start_remote (this=0x5555587882e0, from_tty=0, extended_p=0) at src/gdb/remote.c:5316 openhwgroup#5 0x00005555564430cf in remote_target::open_1 (name=0x55555878525e "| gdbserver - /tmp/a.out", from_tty=0, extended_p=0) at src/gdb/remote.c:6175 openhwgroup#6 0x0000555556441707 in remote_target::open (name=0x55555878525e "| gdbserver - /tmp/a.out", from_tty=0) at src/gdb/remote.c:5338 openhwgroup#7 0x00005555565ea63f in open_target (args=0x55555878525e "| gdbserver - /tmp/a.out", from_tty=0, command=0x555558589280) at src/gdb/target.c:824 openhwgroup#8 0x0000555555f0d89a in cmd_func (cmd=0x555558589280, args=0x55555878525e "| gdbserver - /tmp/a.out", from_tty=0) at src/gdb/cli/cli-decode.c:2735 openhwgroup#9 0x000055555661fb42 in execute_command (p=0x55555878529e "t", from_tty=0) at src/gdb/top.c:575 openhwgroup#10 0x0000555555f1a506 in execute_control_command_1 (cmd=0x555558756f00, from_tty=0) at src/gdb/cli/cli-script.c:529 openhwgroup#11 0x0000555555f1abea in execute_control_command (cmd=0x555558756f00, from_tty=0) at src/gdb/cli/cli-script.c:701 openhwgroup#12 0x0000555555f19fc7 in execute_control_commands (cmdlines=0x555558756f00, from_tty=0) at src/gdb/cli/cli-script.c:411 openhwgroup#13 0x0000555556400d91 in execute_gdb_command (self=0x7ffff43b5d00, args=0x7ffff440ab60, kw=0x0) at src/gdb/python/python.c:700 openhwgroup#14 0x00007ffff7a96023 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#15 0x00007ffff7a4dadc in _PyObject_MakeTpCall () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#16 0x00007ffff79e9a1c in _PyEval_EvalFrameDefault () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#17 0x00007ffff7b303af in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#18 0x00007ffff7a50358 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#19 0x00007ffff7a4f3f4 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#20 0x00007ffff7a4f883 in PyObject_CallFunctionObjArgs () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#21 0x00005555563a9758 in evpy_emit_event (event=0x7ffff42b5430, registry=0x7ffff42b4690) at src/gdb/python/py-event.c:104 openhwgroup#22 0x00005555563cb874 in emit_new_objfile_event (objfile=0x555558761700) at src/gdb/python/py-newobjfileevent.c:52 openhwgroup#23 0x00005555563b53bc in python_new_objfile (objfile=0x555558761700) at src/gdb/python/py-inferior.c:195 openhwgroup#24 0x0000555555d6dff0 in std::__invoke_impl<void, void (*&)(objfile*), objfile*> (__f=@0x5555585b5860: 0x5555563b5360 <python_new_objfile(objfile*)>) at /usr/include/c++/11/bits/invoke.h:61 openhwgroup#25 0x0000555555d6be18 in std::__invoke_r<void, void (*&)(objfile*), objfile*> (__fn=@0x5555585b5860: 0x5555563b5360 <python_new_objfile(objfile*)>) at /usr/include/c++/11/bits/invoke.h:111 openhwgroup#26 0x0000555555d69661 in std::_Function_handler<void (objfile*), void (*)(objfile*)>::_M_invoke(std::_Any_data const&, objfile*&&) (__functor=..., __args#0=@0x7fffffffd080: 0x555558761700) at /usr/include/c++/11/bits/std_function.h:290 openhwgroup#27 0x0000555556314caf in std::function<void (objfile*)>::operator()(objfile*) const (this=0x5555585b5860, __args#0=0x555558761700) at /usr/include/c++/11/bits/std_function.h:590 openhwgroup#28 0x000055555631444e in gdb::observers::observable<objfile*>::notify (this=0x55555836eea0 <gdb::observers::new_objfile>, args#0=0x555558761700) at src/gdb/../gdbsupport/observable.h:166 openhwgroup#29 0x0000555556599b3f in symbol_file_add_with_addrs (abfd=..., name=0x55555875d310 "/lib64/ld-linux-x86-64.so.2", add_flags=..., addrs=0x7fffffffd2f0, flags=..., parent=0x0) at src/gdb/symfile.c:1125 openhwgroup#30 0x0000555556599ca4 in symbol_file_add_from_bfd (abfd=..., name=0x55555875d310 "/lib64/ld-linux-x86-64.so.2", add_flags=..., addrs=0x7fffffffd2f0, flags=..., parent=0x0) at src/gdb/symfile.c:1160 openhwgroup#31 0x0000555556546371 in solib_read_symbols (so=..., flags=...) at src/gdb/solib.c:692 openhwgroup#32 0x0000555556546f0f in solib_add (pattern=0x0, from_tty=0, readsyms=1) at src/gdb/solib.c:1015 openhwgroup#33 0x0000555556539891 in enable_break (info=0x55555874e180, from_tty=0) at src/gdb/solib-svr4.c:2416 openhwgroup#34 0x000055555653b305 in svr4_solib_create_inferior_hook (from_tty=0) at src/gdb/solib-svr4.c:3058 openhwgroup#35 0x0000555556547cee in solib_create_inferior_hook (from_tty=0) at src/gdb/solib.c:1217 openhwgroup#36 0x0000555556196f6a in post_create_inferior (from_tty=0) at src/gdb/infcmd.c:275 openhwgroup#37 0x0000555556197670 in run_command_1 (args=0x0, from_tty=1, run_how=RUN_NORMAL) at src/gdb/infcmd.c:486 openhwgroup#38 0x000055555619783f in run_command (args=0x0, from_tty=1) at src/gdb/infcmd.c:512 openhwgroup#39 0x0000555555f0798d in do_simple_func (args=0x0, from_tty=1, c=0x555558567510) at src/gdb/cli/cli-decode.c:95 openhwgroup#40 0x0000555555f0d89a in cmd_func (cmd=0x555558567510, args=0x0, from_tty=1) at src/gdb/cli/cli-decode.c:2735 openhwgroup#41 0x000055555661fb42 in execute_command (p=0x7fffffffe2c4 "", from_tty=1) at src/gdb/top.c:575 openhwgroup#42 0x000055555626303b in catch_command_errors (command=0x55555661f4ab <execute_command(char const*, int)>, arg=0x7fffffffe2c1 "run", from_tty=1, do_bp_actions=true) at src/gdb/main.c:513 openhwgroup#43 0x000055555626328a in execute_cmdargs (cmdarg_vec=0x7fffffffdaf0, file_type=CMDARG_FILE, cmd_type=CMDARG_COMMAND, ret=0x7fffffffda3c) at src/gdb/main.c:612 openhwgroup#44 0x0000555556264849 in captured_main_1 (context=0x7fffffffdd40) at src/gdb/main.c:1293 openhwgroup#45 0x0000555556264a7f in captured_main (data=0x7fffffffdd40) at src/gdb/main.c:1314 openhwgroup#46 0x0000555556264b2e in gdb_main (args=0x7fffffffdd40) at src/gdb/main.c:1343 openhwgroup#47 0x0000555555ceccab in main (argc=9, argv=0x7fffffffde78) at src/gdb/gdb.c:39 (top-gdb) The use of the "target remote" command here is just an example. In principle, we would reproduce the problem with any command that triggers an invocation of `normal_stop`. To omit enabling the stdin in `normal_stop`, we would have to check the context we are in. Since we cannot do that, we add a new field to `struct ui` to track whether the prompt was already blocked, and set the tracker flag in the Python context before executing a GDB command. After applying this patch, the output becomes ... Reading symbols from a.out... Starting program: /tmp/a.out loading /lib64/ld-linux-x86-64.so.2 [New inferior 2] Added inferior 2 [Switching to inferior 2 [<null>] (<noexec>)] stdin/stdout redirected Process /tmp/a.out created; pid = 3032261 Remote debugging using stdio Reading /tmp/a.out from remote target... ... [Switching to inferior 1 [process 3032255] (/tmp/a.out)] [Switching to thread 1.1 (process 3032255)] #0 0x00007ffff7fe3290 in ?? () from /lib64/ld-linux-x86-64.so.2 [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". [Inferior 1 (process 3032255) exited normally] (gdb) Let's now consider a secondary scenario, where the command executed from the Python raises an error. As an example, suppose we have the Python file below: def handle_new_objfile_event(self, event): ... print("loading " + event.new_objfile.filename) self.processed_objfile = True gdb.execute('print a') The executed command, "print a", gives an error because "a" is not defined. Without this patch, we see the behavior below, where the prompt is again placed incorrectly: ... Reading symbols from /tmp/a.out... Starting program: /tmp/a.out loading /lib64/ld-linux-x86-64.so.2 Python Exception <class 'gdb.error'>: No symbol "a" in current context. (gdb) [Inferior 1 (process 3980401) exited normally] This time, `async_enable_stdin` is called from the 'catch' block in `execute_gdb_command`: (top-gdb) bt #0 async_enable_stdin () at src/gdb/event-top.c:523 openhwgroup#1 0x0000555556400f0a in execute_gdb_command (self=0x7ffff43b5d00, args=0x7ffff440ab60, kw=0x0) at src/gdb/python/python.c:713 openhwgroup#2 0x00007ffff7a96023 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#3 0x00007ffff7a4dadc in _PyObject_MakeTpCall () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#4 0x00007ffff79e9a1c in _PyEval_EvalFrameDefault () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#5 0x00007ffff7b303af in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#6 0x00007ffff7a50358 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#7 0x00007ffff7a4f3f4 in ?? () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#8 0x00007ffff7a4f883 in PyObject_CallFunctionObjArgs () from /lib/x86_64-linux-gnu/libpython3.10.so.1.0 openhwgroup#9 0x00005555563a9758 in evpy_emit_event (event=0x7ffff42b5430, registry=0x7ffff42b4690) at src/gdb/python/py-event.c:104 openhwgroup#10 0x00005555563cb874 in emit_new_objfile_event (objfile=0x555558761410) at src/gdb/python/py-newobjfileevent.c:52 openhwgroup#11 0x00005555563b53bc in python_new_objfile (objfile=0x555558761410) at src/gdb/python/py-inferior.c:195 openhwgroup#12 0x0000555555d6dff0 in std::__invoke_impl<void, void (*&)(objfile*), objfile*> (__f=@0x5555585b5860: 0x5555563b5360 <python_new_objfile(objfile*)>) at /usr/include/c++/11/bits/invoke.h:61 openhwgroup#13 0x0000555555d6be18 in std::__invoke_r<void, void (*&)(objfile*), objfile*> (__fn=@0x5555585b5860: 0x5555563b5360 <python_new_objfile(objfile*)>) at /usr/include/c++/11/bits/invoke.h:111 openhwgroup#14 0x0000555555d69661 in std::_Function_handler<void (objfile*), void (*)(objfile*)>::_M_invoke(std::_Any_data const&, objfile*&&) (__functor=..., __args#0=@0x7fffffffd080: 0x555558761410) at /usr/include/c++/11/bits/std_function.h:290 openhwgroup#15 0x0000555556314caf in std::function<void (objfile*)>::operator()(objfile*) const (this=0x5555585b5860, __args#0=0x555558761410) at /usr/include/c++/11/bits/std_function.h:590 openhwgroup#16 0x000055555631444e in gdb::observers::observable<objfile*>::notify (this=0x55555836eea0 <gdb::observers::new_objfile>, args#0=0x555558761410) at src/gdb/../gdbsupport/observable.h:166 openhwgroup#17 0x0000555556599b3f in symbol_file_add_with_addrs (abfd=..., name=0x55555875d020 "/lib64/ld-linux-x86-64.so.2", add_flags=..., addrs=0x7fffffffd2f0, flags=..., parent=0x0) at src/gdb/symfile.c:1125 openhwgroup#18 0x0000555556599ca4 in symbol_file_add_from_bfd (abfd=..., name=0x55555875d020 "/lib64/ld-linux-x86-64.so.2", add_flags=..., addrs=0x7fffffffd2f0, flags=..., parent=0x0) at src/gdb/symfile.c:1160 openhwgroup#19 0x0000555556546371 in solib_read_symbols (so=..., flags=...) at src/gdb/solib.c:692 openhwgroup#20 0x0000555556546f0f in solib_add (pattern=0x0, from_tty=0, readsyms=1) at src/gdb/solib.c:1015 openhwgroup#21 0x0000555556539891 in enable_break (info=0x55555874a670, from_tty=0) at src/gdb/solib-svr4.c:2416 openhwgroup#22 0x000055555653b305 in svr4_solib_create_inferior_hook (from_tty=0) at src/gdb/solib-svr4.c:3058 openhwgroup#23 0x0000555556547cee in solib_create_inferior_hook (from_tty=0) at src/gdb/solib.c:1217 openhwgroup#24 0x0000555556196f6a in post_create_inferior (from_tty=0) at src/gdb/infcmd.c:275 openhwgroup#25 0x0000555556197670 in run_command_1 (args=0x0, from_tty=1, run_how=RUN_NORMAL) at src/gdb/infcmd.c:486 openhwgroup#26 0x000055555619783f in run_command (args=0x0, from_tty=1) at src/gdb/infcmd.c:512 openhwgroup#27 0x0000555555f0798d in do_simple_func (args=0x0, from_tty=1, c=0x555558567510) at src/gdb/cli/cli-decode.c:95 openhwgroup#28 0x0000555555f0d89a in cmd_func (cmd=0x555558567510, args=0x0, from_tty=1) at src/gdb/cli/cli-decode.c:2735 openhwgroup#29 0x000055555661fb42 in execute_command (p=0x7fffffffe2c4 "", from_tty=1) at src/gdb/top.c:575 openhwgroup#30 0x000055555626303b in catch_command_errors (command=0x55555661f4ab <execute_command(char const*, int)>, arg=0x7fffffffe2c1 "run", from_tty=1, do_bp_actions=true) at src/gdb/main.c:513 openhwgroup#31 0x000055555626328a in execute_cmdargs (cmdarg_vec=0x7fffffffdaf0, file_type=CMDARG_FILE, cmd_type=CMDARG_COMMAND, ret=0x7fffffffda3c) at src/gdb/main.c:612 openhwgroup#32 0x0000555556264849 in captured_main_1 (context=0x7fffffffdd40) at src/gdb/main.c:1293 openhwgroup#33 0x0000555556264a7f in captured_main (data=0x7fffffffdd40) at src/gdb/main.c:1314 openhwgroup#34 0x0000555556264b2e in gdb_main (args=0x7fffffffdd40) at src/gdb/main.c:1343 openhwgroup#35 0x0000555555ceccab in main (argc=9, argv=0x7fffffffde78) at src/gdb/gdb.c:39 (top-gdb) Again, after we enable stdin, GDB continues with its normal flow of the 'run' command and receives the inferior's exit event, where it would have enabled stdin, if we had not done it prematurely. (top-gdb) bt #0 async_enable_stdin () at src/gdb/event-top.c:523 openhwgroup#1 0x00005555561c3acd in normal_stop () at src/gdb/infrun.c:9432 openhwgroup#2 0x00005555561b5bf1 in fetch_inferior_event () at src/gdb/infrun.c:4700 openhwgroup#3 0x000055555618d6a7 in inferior_event_handler (event_type=INF_REG_EVENT) at src/gdb/inf-loop.c:42 openhwgroup#4 0x000055555620ecdb in handle_target_event (error=0, client_data=0x0) at src/gdb/linux-nat.c:4316 openhwgroup#5 0x0000555556f33035 in handle_file_event (file_ptr=0x5555587024e0, ready_mask=1) at src/gdbsupport/event-loop.cc:573 openhwgroup#6 0x0000555556f3362f in gdb_wait_for_event (block=0) at src/gdbsupport/event-loop.cc:694 openhwgroup#7 0x0000555556f322cd in gdb_do_one_event (mstimeout=-1) at src/gdbsupport/event-loop.cc:217 openhwgroup#8 0x0000555556262df8 in start_event_loop () at src/gdb/main.c:407 openhwgroup#9 0x0000555556262f85 in captured_command_loop () at src/gdb/main.c:471 openhwgroup#10 0x0000555556264a84 in captured_main (data=0x7fffffffdd40) at src/gdb/main.c:1324 openhwgroup#11 0x0000555556264b2e in gdb_main (args=0x7fffffffdd40) at src/gdb/main.c:1343 openhwgroup#12 0x0000555555ceccab in main (argc=9, argv=0x7fffffffde78) at src/gdb/gdb.c:39 (top-gdb) The solution implemented by this patch addresses the problem. After applying the patch, the output becomes $ gdb -q -ex "source file.py" -ex "run" --args a.out Reading symbols from /tmp/a.out... Starting program: /tmp/a.out loading /lib64/ld-linux-x86-64.so.2 Python Exception <class 'gdb.error'>: No symbol "a" in current context. [Inferior 1 (process 3984511) exited normally] (gdb) Regression-tested on X86_64 Linux using the default board file (i.e. unix). Co-Authored-By: Oguzhan Karakaya <oguzhan.karakaya@intel.com> Reviewed-By: Guinevere Larsen <blarsen@redhat.com> Approved-By: Tom Tromey <tom@tromey.com>
MaryBennett
pushed a commit
to MaryBennett/corev-binutils-gdb
that referenced
this pull request
May 14, 2024
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 openhwgroup#2 <signal handler called> openhwgroup#3 0x0000ffff74b977b4 in raise () from /lib64/libc.so.6 openhwgroup#4 0x0000ffff74b98c18 in abort () from /lib64/libc.so.6 openhwgroup#5 0x0000ffff74ea26f4 in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib64/libstdc++.so.6 openhwgroup#6 0x0000ffff74ea011c in ?? () from /usr/lib64/libstdc++.so.6 openhwgroup#7 0x0000ffff74ea0180 in std::terminate() () from /usr/lib64/libstdc++.so.6 openhwgroup#8 0x0000ffff74ea0464 in __cxa_throw () from /usr/lib64/libstdc++.so.6 openhwgroup#9 0x0000000001548870 in throw_it (reason=RETURN_ERROR, error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed", ap=...) at gdbsupport/common-exceptions.cc:203 openhwgroup#10 0x0000000001548920 in throw_verror (error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed", ap=...) at gdbsupport/common-exceptions.cc:211 openhwgroup#11 0x0000000001548a00 in throw_error (error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed") at gdbsupport/common-exceptions.cc:226 openhwgroup#12 0x0000000000ac8f2c in remote_target::readchar (this=0x233d3d90, timeout=2) at gdb/remote.c:9856 openhwgroup#13 0x0000000000ac9f04 in remote_target::getpkt (this=0x233d3d90, buf=0x233d40a8, forever=false, is_notif=0x0) at gdb/remote.c:10326 openhwgroup#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 openhwgroup#15 0x0000000000ad03bc in remote_target::fileio_fstat (this=0x233d3d90, fd=3, st=0xfffff1a3d020, remote_errno=0xfffff1a3cf38) at gdb/remote.c:12979 openhwgroup#16 0x0000000000c39878 in target_fileio_fstat (fd=0, sb=0xfffff1a3d020, target_errno=0xfffff1a3cf38) at gdb/target.c:3315 openhwgroup#17 0x00000000007eee5c in target_fileio_stream::stat (this=0x233d4400, abfd=0x2323fc40, sb=0xfffff1a3d020) at gdb/gdb_bfd.c:467 openhwgroup#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 openhwgroup#19 0x00000000007f015c in <lambda(bfd*, void*, stat*)>::_FUN(bfd *, void *, stat *) () at gdb/gdb_bfd.c:956 openhwgroup#20 0x0000000000f9b838 in opncls_bstat (abfd=0x2323fc40, sb=0xfffff1a3d020) at bfd/opncls.c:665 openhwgroup#21 0x0000000000f90adc in bfd_stat (abfd=0x2323fc40, statbuf=0xfffff1a3d020) at bfd/bfdio.c:431 openhwgroup#22 0x000000000065fe20 in reopen_exec_file () at gdb/corefile.c:52 openhwgroup#23 0x0000000000c3a3e8 in generic_mourn_inferior () at gdb/target.c:3642 openhwgroup#24 0x0000000000abf3f0 in remote_unpush_target (target=0x233d3d90) at gdb/remote.c:6067 openhwgroup#25 0x0000000000aca8b0 in remote_target::mourn_inferior (this=0x233d3d90) at gdb/remote.c:10587 openhwgroup#26 0x0000000000c387cc in target_mourn_inferior ( ptid=<error reading variable: Cannot access memory at address 0x2d310>) at gdb/target.c:2738 openhwgroup#27 0x0000000000abfff0 in remote_target::remote_detach_1 (this=0x233d3d90, inf=0x22fce540, from_tty=1) at gdb/remote.c:6421 openhwgroup#28 0x0000000000ac0094 in remote_target::detach (this=0x233d3d90, inf=0x22fce540, from_tty=1) at gdb/remote.c:6436 openhwgroup#29 0x0000000000c37c3c in target_detach (inf=0x22fce540, from_tty=1) at gdb/target.c:2526 openhwgroup#30 0x0000000000860424 in detach_command (args=0x0, from_tty=1) at gdb/infcmd.c:2817 openhwgroup#31 0x000000000060b594 in do_simple_func (args=0x0, from_tty=1, c=0x231431a0) at gdb/cli/cli-decode.c:94 openhwgroup#32 0x00000000006108c8 in cmd_func (cmd=0x231431a0, args=0x0, from_tty=1) at gdb/cli/cli-decode.c:2741 openhwgroup#33 0x0000000000c65a94 in execute_command (p=0x232e52f6 "", from_tty=1) at gdb/top.c:570 openhwgroup#34 0x00000000007a7d2c in command_handler (command=0x232e52f0 "") at gdb/event-top.c:566 openhwgroup#35 0x00000000007a8290 in command_line_handler (rl=...) at gdb/event-top.c:802 openhwgroup#36 0x0000000000c9092c in tui_command_line_handler (rl=...) at gdb/tui/tui-interp.c:103 openhwgroup#37 0x00000000007a750c in gdb_rl_callback_handler (rl=0x23385330 "detach") at gdb/event-top.c:258 openhwgroup#38 0x0000000000d910f4 in rl_callback_read_char () at readline/readline/callback.c:290 openhwgroup#39 0x00000000007a7338 in gdb_rl_callback_read_char_wrapper_noexcept () at gdb/event-top.c:194 openhwgroup#40 0x00000000007a73f0 in gdb_rl_callback_read_char_wrapper (client_data=0x22fbf640) at gdb/event-top.c:233 openhwgroup#41 0x0000000000cbee1c in stdin_event_handler (error=0, client_data=0x22fbf640) at gdb/ui.c:154 openhwgroup#42 0x000000000154ed60 in handle_file_event (file_ptr=0x232be730, ready_mask=1) at gdbsupport/event-loop.cc:572 openhwgroup#43 0x000000000154f21c in gdb_wait_for_event (block=1) at gdbsupport/event-loop.cc:693 openhwgroup#44 0x000000000154dec4 in gdb_do_one_event (mstimeout=-1) at gdbsupport/event-loop.cc:263 openhwgroup#45 0x0000000000910f98 in start_event_loop () at gdb/main.c:400 openhwgroup#46 0x0000000000911130 in captured_command_loop () at gdb/main.c:464 openhwgroup#47 0x0000000000912b5c in captured_main (data=0xfffff1a3db58) at gdb/main.c:1338 openhwgroup#48 0x0000000000912bf4 in gdb_main (args=0xfffff1a3db58) at gdb/main.c:1357 openhwgroup#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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
gas/testsuite/ChangeLog.COREV:
Signed-off-by: Jessica Mills jessica.mills@embecosm.com