[v2,gdb/remote] Fix abort on REMOTE_CLOSE_ERROR
Checks
| Context |
Check |
Description |
| linaro-tcwg-bot/tcwg_gdb_build--master-aarch64 |
success
|
Testing passed
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| linaro-tcwg-bot/tcwg_gdb_build--master-arm |
success
|
Testing passed
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| linaro-tcwg-bot/tcwg_gdb_check--master-arm |
success
|
Testing passed
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| linaro-tcwg-bot/tcwg_gdb_check--master-aarch64 |
success
|
Testing passed
|
Commit Message
When running test-case gdb.server/connect-with-no-symbol-file.exp on
aarch64-linux (specifically, an opensuse leap 15.5 container on a
fedora asahi 39 system), I run into:
...
(gdb) detach^M
Detaching from program: target:connect-with-no-symbol-file, process 185104^M
Ending remote debugging.^M
terminate called after throwing an instance of 'gdb_exception_error'^M
...
The detailed backtrace of the corefile is:
...
(gdb) bt
#0 0x0000ffff75504f54 in raise () from /lib64/libpthread.so.0
#1 0x00000000007a86b4 in handle_fatal_signal (sig=6)
at gdb/event-top.c:926
#2 <signal handler called>
#3 0x0000ffff74b977b4 in raise () from /lib64/libc.so.6
#4 0x0000ffff74b98c18 in abort () from /lib64/libc.so.6
#5 0x0000ffff74ea26f4 in __gnu_cxx::__verbose_terminate_handler() ()
from /usr/lib64/libstdc++.so.6
#6 0x0000ffff74ea011c in ?? () from /usr/lib64/libstdc++.so.6
#7 0x0000ffff74ea0180 in std::terminate() () from /usr/lib64/libstdc++.so.6
#8 0x0000ffff74ea0464 in __cxa_throw () from /usr/lib64/libstdc++.so.6
#9 0x0000000001548870 in throw_it (reason=RETURN_ERROR,
error=TARGET_CLOSE_ERROR, fmt=0x16c7810 "Remote connection closed", ap=...)
at gdbsupport/common-exceptions.cc:203
#10 0x0000000001548920 in throw_verror (error=TARGET_CLOSE_ERROR,
fmt=0x16c7810 "Remote connection closed", ap=...)
at gdbsupport/common-exceptions.cc:211
#11 0x0000000001548a00 in throw_error (error=TARGET_CLOSE_ERROR,
fmt=0x16c7810 "Remote connection closed")
at gdbsupport/common-exceptions.cc:226
#12 0x0000000000ac8f2c in remote_target::readchar (this=0x233d3d90, timeout=2)
at gdb/remote.c:9856
#13 0x0000000000ac9f04 in remote_target::getpkt (this=0x233d3d90,
buf=0x233d40a8, forever=false, is_notif=0x0) at gdb/remote.c:10326
#14 0x0000000000acf3d0 in remote_target::remote_hostio_send_command
(this=0x233d3d90, command_bytes=13, which_packet=17,
remote_errno=0xfffff1a3cf38, attachment=0xfffff1a3ce88,
attachment_len=0xfffff1a3ce90) at gdb/remote.c:12567
#15 0x0000000000ad03bc in remote_target::fileio_fstat (this=0x233d3d90, fd=3,
st=0xfffff1a3d020, remote_errno=0xfffff1a3cf38)
at gdb/remote.c:12979
#16 0x0000000000c39878 in target_fileio_fstat (fd=0, sb=0xfffff1a3d020,
target_errno=0xfffff1a3cf38) at gdb/target.c:3315
#17 0x00000000007eee5c in target_fileio_stream::stat (this=0x233d4400,
abfd=0x2323fc40, sb=0xfffff1a3d020) at gdb/gdb_bfd.c:467
#18 0x00000000007f012c in <lambda(bfd*, void*, stat*)>::operator()(bfd *,
void *, stat *) const (__closure=0x0, abfd=0x2323fc40, stream=0x233d4400,
sb=0xfffff1a3d020) at gdb/gdb_bfd.c:955
#19 0x00000000007f015c in <lambda(bfd*, void*, stat*)>::_FUN(bfd *, void *,
stat *) () at gdb/gdb_bfd.c:956
#20 0x0000000000f9b838 in opncls_bstat (abfd=0x2323fc40, sb=0xfffff1a3d020)
at bfd/opncls.c:665
#21 0x0000000000f90adc in bfd_stat (abfd=0x2323fc40, statbuf=0xfffff1a3d020)
at bfd/bfdio.c:431
#22 0x000000000065fe20 in reopen_exec_file () at gdb/corefile.c:52
#23 0x0000000000c3a3e8 in generic_mourn_inferior ()
at gdb/target.c:3642
#24 0x0000000000abf3f0 in remote_unpush_target (target=0x233d3d90)
at gdb/remote.c:6067
#25 0x0000000000aca8b0 in remote_target::mourn_inferior (this=0x233d3d90)
at gdb/remote.c:10587
#26 0x0000000000c387cc in target_mourn_inferior (
ptid=<error reading variable: Cannot access memory at address 0x2d310>)
at gdb/target.c:2738
#27 0x0000000000abfff0 in remote_target::remote_detach_1 (this=0x233d3d90,
inf=0x22fce540, from_tty=1) at gdb/remote.c:6421
#28 0x0000000000ac0094 in remote_target::detach (this=0x233d3d90,
inf=0x22fce540, from_tty=1) at gdb/remote.c:6436
#29 0x0000000000c37c3c in target_detach (inf=0x22fce540, from_tty=1)
at gdb/target.c:2526
#30 0x0000000000860424 in detach_command (args=0x0, from_tty=1)
at gdb/infcmd.c:2817
#31 0x000000000060b594 in do_simple_func (args=0x0, from_tty=1, c=0x231431a0)
at gdb/cli/cli-decode.c:94
#32 0x00000000006108c8 in cmd_func (cmd=0x231431a0, args=0x0, from_tty=1)
at gdb/cli/cli-decode.c:2741
#33 0x0000000000c65a94 in execute_command (p=0x232e52f6 "", from_tty=1)
at gdb/top.c:570
#34 0x00000000007a7d2c in command_handler (command=0x232e52f0 "")
at gdb/event-top.c:566
#35 0x00000000007a8290 in command_line_handler (rl=...)
at gdb/event-top.c:802
#36 0x0000000000c9092c in tui_command_line_handler (rl=...)
at gdb/tui/tui-interp.c:103
#37 0x00000000007a750c in gdb_rl_callback_handler (rl=0x23385330 "detach")
at gdb/event-top.c:258
#38 0x0000000000d910f4 in rl_callback_read_char ()
at readline/readline/callback.c:290
#39 0x00000000007a7338 in gdb_rl_callback_read_char_wrapper_noexcept ()
at gdb/event-top.c:194
#40 0x00000000007a73f0 in gdb_rl_callback_read_char_wrapper
(client_data=0x22fbf640) at gdb/event-top.c:233
#41 0x0000000000cbee1c in stdin_event_handler (error=0, client_data=0x22fbf640)
at gdb/ui.c:154
#42 0x000000000154ed60 in handle_file_event (file_ptr=0x232be730, ready_mask=1)
at gdbsupport/event-loop.cc:572
#43 0x000000000154f21c in gdb_wait_for_event (block=1)
at gdbsupport/event-loop.cc:693
#44 0x000000000154dec4 in gdb_do_one_event (mstimeout=-1)
at gdbsupport/event-loop.cc:263
#45 0x0000000000910f98 in start_event_loop () at gdb/main.c:400
#46 0x0000000000911130 in captured_command_loop () at gdb/main.c:464
#47 0x0000000000912b5c in captured_main (data=0xfffff1a3db58)
at gdb/main.c:1338
#48 0x0000000000912bf4 in gdb_main (args=0xfffff1a3db58)
at gdb/main.c:1357
#49 0x00000000004170f4 in main (argc=10, argv=0xfffff1a3dcc8)
at gdb/gdb.c:38
(gdb)
...
The abort happens because a c++ exception escapes to c code, specifically
opncls_bstat in bfd/opncls.c. Compiling with -fexceptions works around this.
Fix this by catching the exception just before it escapes, in stat_trampoline
and likewise in few similar spot.
Add a new template catch_exceptions to do so in a consistent way.
Tested on aarch64-linux.
PR remote/31577
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31577
---
gdb/gdb_bfd.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 53 insertions(+), 3 deletions(-)
base-commit: 20eee7540b9f2615f7661393756fec0bb62a1495
Comments
On 2024-04-20 10:14, Tom de Vries wrote:
> +
> /* See gdb_bfd.h. */
>
> gdb_bfd_ref_ptr
> @@ -938,21 +961,48 @@ gdb_bfd_openr_iovec (const char *filename, const char *target,
> auto do_open = [] (bfd *nbfd, void *closure) -> void *
> {
> auto real_opener = static_cast<gdb_iovec_opener_ftype *> (closure);
> - return (*real_opener) (nbfd);
> + /* Prevent exceptions from escaping to C code and triggering an abort. */
> + auto res = catch_exceptions<gdb_bfd_iovec_base *, nullptr> ([&] {
> + return (*real_opener) (nbfd);
> + });
Please use the lambda formatting described at:
https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards#Indentation_of_lambdas_as_parameters
> + if (res == nullptr)
> + {
> + errno = EIO;
> + bfd_set_error (bfd_error_system_call);
> + }
> + return res;
> };
>
> auto read_trampoline = [] (bfd *nbfd, void *stream, void *buf,
> file_ptr nbytes, file_ptr offset) -> file_ptr
> {
> gdb_bfd_iovec_base *obj = static_cast<gdb_bfd_iovec_base *> (stream);
> - return obj->read (nbfd, buf, nbytes, offset);
> + /* Prevent exceptions from escaping to C code and triggering an abort. */
> + auto res = catch_exceptions<long int, -1> ([&] {
> + return obj->read (nbfd, buf, nbytes, offset);
> + });
Ditto re. formatting.
> + if (res == -1)
> + {
> + errno = EIO;
> + bfd_set_error (bfd_error_system_call);
> + }
> + return res;
> };
>
> auto stat_trampoline = [] (struct bfd *abfd, void *stream,
> struct stat *sb) -> int
> {
> gdb_bfd_iovec_base *obj = static_cast<gdb_bfd_iovec_base *> (stream);
> - return obj->stat (abfd, sb);
> + /* Prevent exceptions from escaping to C code and triggering an abort. */
> + auto res = catch_exceptions<int, -1> ([&] {
> + return obj->stat (abfd, sb);
> + });
Ditto.
> + if (res == -1)
> + {
> + errno = EIO;
> + bfd_set_error (bfd_error_system_call);
> + }
> + return res;
> };
>
> auto close_trampoline = [] (struct bfd *nbfd, void *stream) -> int
>
> base-commit: 20eee7540b9f2615f7661393756fec0bb62a1495
Otherwise:
Approved-by: Pedro Alves <pedro@palves.net>
Thanks.
On 4/26/24 18:03, Pedro Alves wrote:
> On 2024-04-20 10:14, Tom de Vries wrote:
>
>> +
>> /* See gdb_bfd.h. */
>>
>> gdb_bfd_ref_ptr
>> @@ -938,21 +961,48 @@ gdb_bfd_openr_iovec (const char *filename, const char *target,
>> auto do_open = [] (bfd *nbfd, void *closure) -> void *
>> {
>> auto real_opener = static_cast<gdb_iovec_opener_ftype *> (closure);
>> - return (*real_opener) (nbfd);
>> + /* Prevent exceptions from escaping to C code and triggering an abort. */
>> + auto res = catch_exceptions<gdb_bfd_iovec_base *, nullptr> ([&] {
>> + return (*real_opener) (nbfd);
>> + });
>
> Please use the lambda formatting described at:
>
> https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards#Indentation_of_lambdas_as_parameters
>
>
>> + if (res == nullptr)
>> + {
>> + errno = EIO;
>> + bfd_set_error (bfd_error_system_call);
>> + }
>> + return res;
>> };
>>
>> auto read_trampoline = [] (bfd *nbfd, void *stream, void *buf,
>> file_ptr nbytes, file_ptr offset) -> file_ptr
>> {
>> gdb_bfd_iovec_base *obj = static_cast<gdb_bfd_iovec_base *> (stream);
>> - return obj->read (nbfd, buf, nbytes, offset);
>> + /* Prevent exceptions from escaping to C code and triggering an abort. */
>> + auto res = catch_exceptions<long int, -1> ([&] {
>> + return obj->read (nbfd, buf, nbytes, offset);
>> + });
>
> Ditto re. formatting.
>
>> + if (res == -1)
>> + {
>> + errno = EIO;
>> + bfd_set_error (bfd_error_system_call);
>> + }
>> + return res;
>> };
>>
>> auto stat_trampoline = [] (struct bfd *abfd, void *stream,
>> struct stat *sb) -> int
>> {
>> gdb_bfd_iovec_base *obj = static_cast<gdb_bfd_iovec_base *> (stream);
>> - return obj->stat (abfd, sb);
>> + /* Prevent exceptions from escaping to C code and triggering an abort. */
>> + auto res = catch_exceptions<int, -1> ([&] {
>> + return obj->stat (abfd, sb);
>> + });
>
> Ditto.
>
>> + if (res == -1)
>> + {
>> + errno = EIO;
>> + bfd_set_error (bfd_error_system_call);
>> + }
>> + return res;
>> };
>>
>> auto close_trampoline = [] (struct bfd *nbfd, void *stream) -> int
>>
>> base-commit: 20eee7540b9f2615f7661393756fec0bb62a1495
>
> Otherwise:
>
> Approved-by: Pedro Alves <pedro@palves.net>
Hi Pedro,
thanks for the review.
Pushed with those changes.
Thanks,
- Tom
>
> Thanks.
>
@@ -929,6 +929,29 @@ gdb_bfd_openw (const char *filename, const char *target)
return gdb_bfd_ref_ptr::new_reference (result);
}
+/* Wrap f (args) and handle exceptions by:
+ - returning val, and
+ - calling set_quit_flag or set_force_quit_flag, if needed. */
+
+template <typename R, R val, typename F, typename... Args>
+static R
+catch_exceptions (F &&f, Args&&... args)
+{
+ try
+ {
+ return f (std::forward<Args> (args)...);
+ }
+ catch (const gdb_exception &ex)
+ {
+ if (ex.reason == RETURN_QUIT)
+ set_quit_flag ();
+ else if (ex.reason == RETURN_FORCED_QUIT)
+ set_force_quit_flag ();
+ }
+
+ return val;
+}
+
/* See gdb_bfd.h. */
gdb_bfd_ref_ptr
@@ -938,21 +961,48 @@ gdb_bfd_openr_iovec (const char *filename, const char *target,
auto do_open = [] (bfd *nbfd, void *closure) -> void *
{
auto real_opener = static_cast<gdb_iovec_opener_ftype *> (closure);
- return (*real_opener) (nbfd);
+ /* Prevent exceptions from escaping to C code and triggering an abort. */
+ auto res = catch_exceptions<gdb_bfd_iovec_base *, nullptr> ([&] {
+ return (*real_opener) (nbfd);
+ });
+ if (res == nullptr)
+ {
+ errno = EIO;
+ bfd_set_error (bfd_error_system_call);
+ }
+ return res;
};
auto read_trampoline = [] (bfd *nbfd, void *stream, void *buf,
file_ptr nbytes, file_ptr offset) -> file_ptr
{
gdb_bfd_iovec_base *obj = static_cast<gdb_bfd_iovec_base *> (stream);
- return obj->read (nbfd, buf, nbytes, offset);
+ /* Prevent exceptions from escaping to C code and triggering an abort. */
+ auto res = catch_exceptions<long int, -1> ([&] {
+ return obj->read (nbfd, buf, nbytes, offset);
+ });
+ if (res == -1)
+ {
+ errno = EIO;
+ bfd_set_error (bfd_error_system_call);
+ }
+ return res;
};
auto stat_trampoline = [] (struct bfd *abfd, void *stream,
struct stat *sb) -> int
{
gdb_bfd_iovec_base *obj = static_cast<gdb_bfd_iovec_base *> (stream);
- return obj->stat (abfd, sb);
+ /* Prevent exceptions from escaping to C code and triggering an abort. */
+ auto res = catch_exceptions<int, -1> ([&] {
+ return obj->stat (abfd, sb);
+ });
+ if (res == -1)
+ {
+ errno = EIO;
+ bfd_set_error (bfd_error_system_call);
+ }
+ return res;
};
auto close_trampoline = [] (struct bfd *nbfd, void *stream) -> int