This changes print_recreate_thread to be a method on breakpoint. This
function is only used as a helper by print_recreate methods, so I
thought this transformation made sense.
The break point after the stepi on Intel is the entry point of the user
signal handler function test_signal_handler. The code at the break point
looks like:
0x<hex address> <test_signal_handler>: endbr64
On PowerPC with a Linux 5.9 kernel or latter, the address where gdb stops
after the stepi is in the vdso code inserted by the kernel. The code at the
breakpoint looks like:
0x<hex address> <__kernel_start_sigtramp_rt64>: bctrl
This is different from other architectures. As discussed below, recent
kernel changes involving the vdso for PowerPC have been made changes to the
signal handler code flow. PowerPC is now stopping in function
__kernel_start_sigtramp_rt64. PowerPC now requires an additional stepi to
reach the user signal handler unlike other architectures.
The bp-permanent.exp and kill-after-signal tests run fine on PowerPC with an
kernel that is older than Linux 5.9.
The PowerPC 64 signal handler was updated by the Linux kernel 5.9-rc1:
commit id: 0138ba5783ae0dcc799ad401a1e8ac8333790df9
powerpc/64/signal: Balance return predictor stack in signal trampoline
An additional change to the PowerPC 64 signal handler was made in Linux
kernel version 5.11-rc7 :
commit id: 24321ac668e452a4942598533d267805f291fdc9
powerpc/64/signal: Fix regression in __kernel_sigtramp_rt64() semantics
The first kernel change, puts code into the user space signal handler (in
the vdso) as a performance optimization to prevent the call/return stack
from getting out of balance. The patch ensures that the entire
user/kernel/vdso cycle is balanced with the addition of the "brctl"
instruction.
The second patch, fixes the semantics of __kernel_sigtramp_rt64(). A new
symbol is introduced to serve as the jump target from the kernel to the
trampoline which now consists of two parts.
The above changes for PowerPC signal handler, causes gdb to stop in the
kernel code not the user signal handler as expected. The kernel dispatches
to the vdso code which in turn calls into the signal handler. PowerPC is
special in that the kernel is using a vdso instruction (bctrl) to enter the
signal handler.
I do not have access to a system with the first patch but not the second. I did
test on Power 9 with the Linux 5.15.0-27-generic kernel. Both tests fail on
this Power 9 system. The two tests also fail on Power 10 with the Linux
5.14.0-70.9.1.el9_0.ppc64le kernel.
The following patch fixes the issue by checking if gdb stopped at "signal
handler called". If gdb stopped there, the tests verifies gdb is in the kernel
function __kernel_start_sigtramp_rt64 then does an additional stepi to reach the
user signal handler. With the patch below, the tests run without errors on both
the Power 9 and Power 10 systems with out any failures.
I hit this just now with a make -j build after touching config.bfd.
mv: cannot stat 'targmatch.new': No such file or directory
make[2]: *** [Makefile:2336: targmatch.h] Error 1
make[2]: *** Waiting for unfinished jobs....
Fix that by not removing the target of the rule, a practice that seems
likely to cause parallel running of the rule recipe. The bug goes
back to 1997, the initial c073470881 commit.
* Makefile.am (targmatch.h): rm the temp file, not targmatch.h.
* Makefile.in: Regenerate.
When running test-case gdb.dwarf2/locexpr-data-member-location.exp with
target board unix/-fno-PIE/-no-pie/-m32 I run into:
...
(gdb) step^M
26 return 0;^M
(gdb) FAIL: gdb.dwarf2/locexpr-data-member-location.exp: step into foo
...
The problem is that the test-case tries to mimic some gdb_compile_shlib
behaviour using:
...
set flags {additional_flags=-fpic debug}
get_func_info foo $flags
...
but this doesn't work with the target board setting, because we end up doing:
...
gcc locexpr-data-member-location-lib.c -fpic -g -lm -fno-PIE -no-pie -m32 \
-o func_addr23029.x
...
while gdb_compile_shlib properly filters out the -fno-PIE -no-pie.
Consequently, the address for foo determined by get_func_info doesn't match
the actual address of foo.
Fix this by printing the address of foo using the result of gdb_compile_shlib.
A rather straightforward patch to change an instance of callback +
void pointer to gdb::function_view, allowing pasing lambdas that
capture, and eliminating the need for the untyped pointer.
Change-Id: I73ed644e7849945265a2c763f79f5456695b0037
By mistake, $target was used instead of $host to configure the gprogng build.
gprofng/ChangeLog
2022-04-28 Vladimir Mezentsev <vladimir.mezentsev@oracle.com>
PR gprofng/29113
PR gprofng/29116
* configure.ac: Use $host instead $target.
* libcollector/configure.ac: Likewise.
* configure: Rebuild.
* libcollector/configure: Rebuild.
Running
$ make check TESTS="gdb.gdb/unittest.exp" RUNTESTFLAGS="--target_board=native-extended-gdbserver"
I get some failures:
Running selftest regcache::cooked_write_test::i386.^M
Self test failed: target already pushed^M
Running selftest regcache::cooked_write_test::i386:intel.^M
Self test failed: target already pushed^M
Running selftest regcache::cooked_write_test::i386:x64-32.^M
Self test failed: target already pushed^M
Running selftest regcache::cooked_write_test::i386:x64-32:intel.^M
Self test failed: target already pushed^M
Running selftest regcache::cooked_write_test::i386:x86-64.^M
Self test failed: target already pushed^M
Running selftest regcache::cooked_write_test::i386:x86-64:intel.^M
Self test failed: target already pushed^M
Running selftest regcache::cooked_write_test::i8086.^M
Self test failed: target already pushed^M
This is because the native-extended-gdbserver automatically connects GDB
to a GDBserver on startup, and therefore pushes a remote target on the
initial inferior. cooked_write_test is currently written in a way that
errors out if the current inferior has a process_stratum_target pushed.
Rewrite it to use scoped_mock_context, so it doesn't depend on the
current inferior (the current one upon entering the function).
Change-Id: I0357f989eacbdecc4bf88b043754451b476052ad
Various packages (glib and gtk4 for example) produces data-only objects
using `ld -r -b binary` or `objcopy`, with no elf header flags set. But
these files also have no code sections, so they should be compatible
with all ABIs.
bfd/
* elfnn-loongarch.c (elfNN_loongarch_merge_private_bfd_data):
Skip ABI checks if the input has no code sections.
Reported-by: Wu Xiaotian <yetist@gmail.com>
Suggested-by: Wang Xuerui <i@xen0n.name>
Signed-off-by: Xi Ruoyao <xry111@mengyan1223.wang>
opcodes/
* s390-opc.c (INSTR_RRF_R0RER): New instruction type.
(MASK_RRF_R0RER): Define mask for new instruction type.
* s390-opc.txt: Use RRF_R0RER for mgrk and RXY_RERRD for mg.
When an IR symbol SYM is referenced in IR via __real_SYM, its resolution
should be LDPR_PREVAILING_DEF, not PREVAILING_DEF_IRONLY, since LTO
doesn't know that __real_SYM should be resolved by SYM.
bfd/
PR ld/29086
* linker.c (bfd_wrapped_link_hash_lookup): Mark SYM is referenced
via __real_SYM.
include/
PR ld/29086
* bfdlink.h (bfd_link_hash_entry): Add ref_real.
ld/
PR ld/29086
* plugin.c (get_symbols): Resolve SYM definition to
LDPR_PREVAILING_DEF for __real_SYM reference.
* testsuite/ld-plugin/lto.exp: Run PR ld/29086 test.
* testsuite/ld-plugin/pr29086.c: New file.
cris support will be built into a 32-bit bfd if using --enable-targets=all
on a 32-bit host, so we may as well make targmatch.h include cris.
* config.bfd (cris): Remove #idef BFD64.
Tidy the dynamic reloc handling code in check_relocs, removing
leftover comments and code from when check_relocs was called as each
object file was read in.
* elf64-ppc.c (ppc64_elf_check_relocs): Tidy dynamic reloc
handling code.
(dec_dynrel_count): Do the same here.
My patches yesterday to unify the DWARF index base classes had a bug
-- namely, I did the wholesale dynamic_cast-to-static_cast too hastily
and introduced a crash. This can be seen by trying to add an index to
a file that has an index, or by running a test like gdb-index-cxx.exp
using the cc-with-debug-names.exp target board.
This patch fixes the crash by introducing a new virtual method and
removing some of the static casts.
For some reason g++ 11.2.1 on s390x produces a spurious warning for
stringop-overread in debuginfod_is_enabled for url_view. Add a new
DIAGNOSTIC_IGNORE_STRINGOP_OVERREAD macro to suppress this warning.
include/ChangeLog:
* diagnostics.h (DIAGNOSTIC_IGNORE_STRINGOP_OVERREAD): New
macro.
gdb/ChangeLog:
* debuginfod-support.c (debuginfod_is_enabled): Use
DIAGNOSTIC_IGNORE_STRINGOP_OVERREAD on s390x.
Luis noticed that the recent changes to gdbserver to make it track
process and threads independently regressed a few gdb.multi/*.exp
tests for aarch64-linux.
We started seeing the following internal error for
gdb.multi/multi-target-continue.exp for example:
Starting program: binutils-gdb/gdb/testsuite/outputs/gdb.multi/multi-target-continue/multi-target-continue ^M
Error in re-setting breakpoint 2: Remote connection closed^M
../../../repos/binutils-gdb/gdb/thread.c:85: internal-error: inferior_thread: Assertion `current_thread_ != nullptr' failed.^M
A problem internal to GDB has been detected,^M
further debugging may prove unreliable.
A backtrace looks like:
#0 thread_regcache_data (thread=thread@entry=0x0) at ../../../repos/binutils-gdb/gdbserver/inferiors.cc:120
#1 0x0000aaaaaaabf0e8 in get_thread_regcache (thread=0x0, fetch=fetch@entry=0) at ../../../repos/binutils-gdb/gdbserver/regcache.cc:31
#2 0x0000aaaaaaad785c in is_64bit_tdesc () at ../../../repos/binutils-gdb/gdbserver/linux-aarch64-low.cc:194
#3 0x0000aaaaaaad8a48 in aarch64_target::sw_breakpoint_from_kind (this=<optimized out>, kind=4, size=0xffffffffef04) at ../../../repos/binutils-gdb/gdbserver/linux-aarch64-low.cc:3226
#4 0x0000aaaaaaabe220 in bp_size (bp=0xaaaaaab6f3d0) at ../../../repos/binutils-gdb/gdbserver/mem-break.cc:226
#5 check_mem_read (mem_addr=187649984471104, buf=buf@entry=0xaaaaaab625d0 "\006", mem_len=mem_len@entry=56) at ../../../repos/binutils-gdb/gdbserver/mem-break.cc:1862
#6 0x0000aaaaaaacc660 in read_inferior_memory (memaddr=<optimized out>, myaddr=0xaaaaaab625d0 "\006", len=56) at ../../../repos/binutils-gdb/gdbserver/target.cc:93
#7 0x0000aaaaaaac3d9c in gdb_read_memory (len=56, myaddr=0xaaaaaab625d0 "\006", memaddr=187649984471104) at ../../../repos/binutils-gdb/gdbserver/server.cc:1071
#8 gdb_read_memory (memaddr=187649984471104, myaddr=0xaaaaaab625d0 "\006", len=56) at ../../../repos/binutils-gdb/gdbserver/server.cc:1048
#9 0x0000aaaaaaac82a4 in process_serial_event () at ../../../repos/binutils-gdb/gdbserver/server.cc:4307
#10 handle_serial_event (err=<optimized out>, client_data=<optimized out>) at ../../../repos/binutils-gdb/gdbserver/server.cc:4520
#11 0x0000aaaaaaafbcd0 in gdb_wait_for_event (block=block@entry=1) at ../../../repos/binutils-gdb/gdbsupport/event-loop.cc:700
#12 0x0000aaaaaaafc0b0 in gdb_wait_for_event (block=1) at ../../../repos/binutils-gdb/gdbsupport/event-loop.cc:596
#13 gdb_do_one_event () at ../../../repos/binutils-gdb/gdbsupport/event-loop.cc:237
#14 0x0000aaaaaaacacb0 in start_event_loop () at ../../../repos/binutils-gdb/gdbserver/server.cc:3518
#15 captured_main (argc=4, argv=<optimized out>) at ../../../repos/binutils-gdb/gdbserver/server.cc:3998
#16 0x0000aaaaaaab66dc in main (argc=<optimized out>, argv=<optimized out>) at ../../../repos/binutils-gdb/gdbserver/server.cc:4084
This sequence of functions is invoked due to a series of conditions:
1 - The probe-based breakpoint mechanism failed (for some reason) so ...
2 - ... gdbserver has to know what type of architecture it is dealing
with so it can pick the right breakpoint kind, so it wants to
check if we have a 64-bit target.
3 - To determine the size of a register, we currently fetch the
current thread's register cache, and the current thread pointer
is now nullptr.
In #3, the current thread is nullptr because gdb_read_memory clears it
on purpose, via set_desired_process, exactly to expose code relying on
the current thread when it shouldn't. It was always possible to end
up in this situation (when the current thread exits), but it was
harder to reproduce before.
This commit fixes it by tweaking is_64bit_tdesc to look at the current
process's tdesc instead of the current thread's tdesc.
Note that the thread's tdesc is itself filled from the process's
tdesc, so this should be equivalent:
struct regcache *
get_thread_regcache (struct thread_info *thread, int fetch)
{
struct regcache *regcache;
regcache = thread_regcache_data (thread);
...
if (regcache == NULL)
{
struct process_info *proc = get_thread_process (thread);
gdb_assert (proc->tdesc != NULL);
regcache = new_register_cache (proc->tdesc);
set_thread_regcache_data (thread, regcache);
}
...
Change-Id: Ibc809d7345e70a2f058b522bdc5cdbdca97e2cdc
start_remote_1 calls remote_check_symbols after things are set up to
give the remote side a chance to look up symbols. One call to
remote_check_symbols sets the "general thread", if needed, and sends one
qSymbol packet. However, a remote target could have more than one
process on initial connection, and this would send a qSymbol for only
one of these processes.
Change it to iterate on all the target's inferiors and send a qSymbol
packet for each one.
I tested this by changing gdbserver to spawn two processes on startup:
diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index 33c42714e72..9b682e9f85f 100644
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -3939,6 +3939,7 @@ captured_main (int argc, char *argv[])
/* Wait till we are at first instruction in program. */
target_create_inferior (program_path.get (), program_args);
+ target_create_inferior (program_path.get (), program_args);
/* We are now (hopefully) stopped at the first instruction of
the target process. This assumes that the target process was
Instead of hacking GDBserver, it should also be possible to test this by
starting manually two inferiors on an "extended-remote" connection,
disconnecting from GDBserver (with the disconnect command), and
re-connecting.
I was able to see qSymbol being sent for each inferior:
[remote] Sending packet: $Hgp828dc.828dc#1f
[remote] Packet received: OK
[remote] Sending packet: $qSymbol::#5b
[remote] Packet received: qSymbol:6764625f6167656e745f6764625f74705f686561705f627566666572
[remote] Sending packet: $qSymbol::6764625f6167656e745f6764625f74705f686561705f627566666572#1e
[remote] Packet received: qSymbol:6e70746c5f76657273696f6e
[remote] Sending packet: $qSymbol::6e70746c5f76657273696f6e#4d
[remote] Packet received: OK
[remote] Sending packet: $Hgp828dd.828dd#21
[remote] Packet received: OK
[remote] Sending packet: $qSymbol::#5b
[remote] Packet received: qSymbol:6764625f6167656e745f6764625f74705f686561705f627566666572
[remote] Sending packet: $qSymbol::6764625f6167656e745f6764625f74705f686561705f627566666572#1e
[remote] Packet received: qSymbol:6e70746c5f76657273696f6e
[remote] Sending packet: $qSymbol::6e70746c5f76657273696f6e#4d
[remote] Packet received: OK
Note that there would probably be more work to be done to fully support
this scenario, more things that need to be done for each discovered
inferior instead of just for one.
Change-Id: I21c4ecf6367391e2e389b560f0b4bd906cf6472f
Commit 152a174956 ("gdb: prune inferiors at end of
fetch_inferior_event, fix intermittent failure of
gdb.threads/fork-plus-threads.exp") broke some tests with the
native-gdbserver board, such as:
(gdb) PASS: gdb.base/step-over-syscall.exp: detach-on-fork=off: follow-fork=child: break cond on target : vfork: break marker
continue^M
Continuing.^M
terminate called after throwing an instance of 'gdb_exception_error'^M
I can manually reproduce the issue by running (just the commands that
the test does as a one liner):
$ ./gdb -q --data-directory=data-directory \
testsuite/outputs/gdb.base/step-over-syscall/step-over-vfork \
-ex "tar rem | ../gdbserver/gdbserver - testsuite/outputs/gdb.base/step-over-syscall/step-over-vfork" \
-ex "b main" \
-ex c \
-ex "d 1" \
-ex "set displaced-stepping off" \
-ex "b *0x7ffff7d7ac5a if main == 0" \
-ex "set detach-on-fork off" \
-ex "set follow-fork-mode child" \
-ex c \
-ex "inferior 1" \
-ex "b marker" \
-ex c
... where 0x7ffff7d7ac5a is the exact address of the vfork syscall
(which can be found by looking at gdb.log).
The important part of the above is that a vfork syscall creates inferior
2, then inferior 2 executes until exit, then we switch back to inferior
1 and try to resume it.
The uncaught exception happens here:
#4 0x00005596969d81a9 in error (fmt=0x559692da9e40 "Cannot execute this command while the target is running.\nUse the \"interrupt\" command to stop the target\nand then try again.")
at /home/simark/src/binutils-gdb/gdbsupport/errors.cc:43
#5 0x0000559695af6f66 in remote_target::putpkt_binary (this=0x617000038080, buf=0x559692da4380 "qSymbol::", cnt=9) at /home/simark/src/binutils-gdb/gdb/remote.c:9560
#6 0x0000559695af6aaf in remote_target::putpkt (this=0x617000038080, buf=0x559692da4380 "qSymbol::") at /home/simark/src/binutils-gdb/gdb/remote.c:9518
#7 0x0000559695ab50dc in remote_target::remote_check_symbols (this=0x617000038080) at /home/simark/src/binutils-gdb/gdb/remote.c:5141
#8 0x0000559695b3cccf in remote_new_objfile (objfile=0x0) at /home/simark/src/binutils-gdb/gdb/remote.c:14600
#9 0x0000559693bc52a9 in std::__invoke_impl<void, void (*&)(objfile*), objfile*> (__f=@0x61b0000167f8: 0x559695b3cb1d <remote_new_objfile(objfile*)>) at /usr/include/c++/11.2.0/bits/invoke.h:61
#10 0x0000559693bb2848 in std::__invoke_r<void, void (*&)(objfile*), objfile*> (__fn=@0x61b0000167f8: 0x559695b3cb1d <remote_new_objfile(objfile*)>) at /usr/include/c++/11.2.0/bits/invoke.h:111
#11 0x0000559693b8dddf in std::_Function_handler<void (objfile*), void (*)(objfile*)>::_M_invoke(std::_Any_data const&, objfile*&&) (__functor=..., __args#0=@0x7ffe0bae0590: 0x0) at /usr/include/c++/11.2.0/bits/std_function.h:291
#12 0x00005596956374b2 in std::function<void (objfile*)>::operator()(objfile*) const (this=0x61b0000167f8, __args#0=0x0) at /usr/include/c++/11.2.0/bits/std_function.h:560
#13 0x0000559695633c64 in gdb::observers::observable<objfile*>::notify (this=0x55969ef5c480 <gdb::observers::new_objfile>, args#0=0x0) at /home/simark/src/binutils-gdb/gdb/../gdbsupport/observable.h:150
#14 0x0000559695df6cc2 in clear_symtab_users (add_flags=...) at /home/simark/src/binutils-gdb/gdb/symfile.c:2873
#15 0x000055969574c263 in program_space::~program_space (this=0x6120000c8a40, __in_chrg=<optimized out>) at /home/simark/src/binutils-gdb/gdb/progspace.c:154
#16 0x0000559694fc086b in delete_inferior (inf=0x61700003bf80) at /home/simark/src/binutils-gdb/gdb/inferior.c:205
#17 0x0000559694fc341f in prune_inferiors () at /home/simark/src/binutils-gdb/gdb/inferior.c:390
#18 0x0000559695017ada in fetch_inferior_event () at /home/simark/src/binutils-gdb/gdb/infrun.c:4293
#19 0x0000559694f629e6 in inferior_event_handler (event_type=INF_REG_EVENT) at /home/simark/src/binutils-gdb/gdb/inf-loop.c:41
#20 0x0000559695b3b0e3 in remote_async_serial_handler (scb=0x6250001ef100, context=0x6170000380a8) at /home/simark/src/binutils-gdb/gdb/remote.c:14466
#21 0x0000559695c59eb7 in run_async_handler_and_reschedule (scb=0x6250001ef100) at /home/simark/src/binutils-gdb/gdb/ser-base.c:138
#22 0x0000559695c5a42a in fd_event (error=0, context=0x6250001ef100) at /home/simark/src/binutils-gdb/gdb/ser-base.c:189
#23 0x00005596969d9ebf in handle_file_event (file_ptr=0x60700005af40, ready_mask=1) at /home/simark/src/binutils-gdb/gdbsupport/event-loop.cc:574
#24 0x00005596969da7fa in gdb_wait_for_event (block=0) at /home/simark/src/binutils-gdb/gdbsupport/event-loop.cc:700
#25 0x00005596969d8539 in gdb_do_one_event () at /home/simark/src/binutils-gdb/gdbsupport/event-loop.cc:212
If I enable "set debug infrun" just before the last continue, we see:
(gdb) continue
Continuing.
[infrun] clear_proceed_status_thread: 965604.965604.0
[infrun] proceed: enter
[infrun] proceed: addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT
[infrun] scoped_disable_commit_resumed: reason=proceeding
[infrun] start_step_over: enter
[infrun] start_step_over: stealing global queue of threads to step, length = 0
[infrun] operator(): step-over queue now empty
[infrun] start_step_over: exit
[infrun] resume_1: step=0, signal=GDB_SIGNAL_0, trap_expected=0, current thread [965604.965604.0] at 0x7ffff7d7ac5c
[infrun] do_target_resume: resume_ptid=965604.0.0, step=0, sig=GDB_SIGNAL_0
[infrun] prepare_to_wait: prepare_to_wait
[infrun] reset: reason=proceeding
[infrun] maybe_set_commit_resumed_all_targets: enabling commit-resumed for target remote
[infrun] maybe_call_commit_resumed_all_targets: calling commit_resumed for target remote
[infrun] proceed: exit
[infrun] fetch_inferior_event: enter
[infrun] scoped_disable_commit_resumed: reason=handling event
[infrun] do_target_wait: Found 2 inferiors, starting at #1
[infrun] random_pending_event_thread: None found.
[infrun] print_target_wait_results: target_wait (-1.0.0 [process -1], status) =
[infrun] print_target_wait_results: 965604.965604.0 [Thread 965604.965604],
[infrun] print_target_wait_results: status->kind = VFORK_DONE
[infrun] handle_inferior_event: status->kind = VFORK_DONE
[infrun] context_switch: Switching context from 0.0.0 to 965604.965604.0
[infrun] handle_vfork_done: not waiting for a vfork-done event
[infrun] start_step_over: enter
[infrun] start_step_over: stealing global queue of threads to step, length = 0
[infrun] operator(): step-over queue now empty
[infrun] start_step_over: exit
[infrun] resume_1: step=0, signal=GDB_SIGNAL_0, trap_expected=0, current thread [965604.965604.0] at 0x7ffff7d7ac5c
[infrun] do_target_resume: resume_ptid=965604.0.0, step=0, sig=GDB_SIGNAL_0
[infrun] prepare_to_wait: prepare_to_wait
[infrun] reset: reason=handling event
[infrun] maybe_set_commit_resumed_all_targets: enabling commit-resumed for target remote
[infrun] maybe_call_commit_resumed_all_targets: calling commit_resumed for target remote
terminate called after throwing an instance of 'gdb_exception_error'
What happens is:
- After doing the "continue" on inferior 1, the remote target gives us
a VFORK_DONE event. The core ignores it and resumes inferior 1.
- Since prune_inferiors is now called after each handled event, in
fetch_inferior_event, it is called after we handled that VFORK_DONE
event and resumed inferior 1.
- Inferior 2 is pruned, which (see backtrace above) causes its program
space to be deleted, which clears the symtabs for that program space,
which calls the new_objfile observable and remote_new_objfile
observer (with a nullptr objfile, to indicate that the previously
loaded symbols have been discarded), which calls
remote_check_symbols.
remote_check_symbols is the function that sends the qSymbol packet, to
let the remote side ask for symbol addresses. The problem is that the
remote target is working in all-stop / sync mode and is currently
resumed. It has sent a vCont packet to resume the target and is waiting
for a stop reply. It can't send any packets in the mean time. That
causes the exception to be thrown.
This wasn't a problem before, when prune_inferiors was called in
normal_stop, because it was always called at a time the target was not
resumed.
An important observation here is that the new_objfile observable is
invoked for a change in inferior 2's program space (inferior 2's program
space is the current program space). Inferior 2 isn't bound to any
process on the remote side (it has exited, that's why it's being
pruned). It doesn't make sense to try to send a qSymbol packet for a
process that doesn't exist on the remote side. remote_check_symbols
actually attempts to avoid that:
/* The remote side has no concept of inferiors that aren't running
yet, it only knows about running processes. If we're connected
but our current inferior is not running, we should not invite the
remote target to request symbol lookups related to its
(unrelated) current process. */
if (!target_has_execution ())
return;
The problem here is that while inferior 2's program space is the current
program space, inferior 1 is the current inferior. So the check above
passes, since inferior has execution. We therefore try to send a
qSymbol packet for inferior 1 in reaction to a change in inferior 2's
program space, that's wrong.
This exposes a conceptual flaw in remote_new_objfile. The "new_objfile"
event concerns a specific program space, which can concern multiple
inferiors, as inferiors can share a program space. We shouldn't
consider the current inferior at all, but instead all inferiors bound to
the affected program space. Especially since the current inferior can
be unrelated to the current program space at that point.
To be clear, we are in this state because ~program_space sets itself as
the current program space, but there is no more inferior having that
program space to switch to, inferior 2 has already been unlinked.
To fix this, make remote_new_objfile iterate on all inferiors bound to
the affected program space. Remove the target_has_execution check from
remote_check_symbols, replace it with an assert. All callers must
ensure that the current inferior has execution before calling it.
Change-Id: Ica643145bcc03115248290fd310cadab8ec8371c
As before, on sufficiently old glibc this conflicts with a global
identifier in the library headers. While there also zap the unusual
padding by blanks.
As already done for PowerPC64, fix dynamic relocs for absolute symbols.
The patch also tidies the dynamic reloc handling code in check_relocs,
removing leftover comments and code from when check_relocs was called
as each object file was read in.
bfd/
* elf32-ppc.c (ppc_elf_check_relocs): Set isym and ifunc earlier.
Rearrange tests for dynamic relocs, handling absolute symbols.
(allocate_dynrelocs): Don't allocate dynamic relocs for locally
defined absolute symbols.
(ppc_elf_size_dynamic_sections): Similarly.
(ppc_elf_relocate_section): Similarly.
ld/
* testsuite/ld-powerpc/abs32-pie.d,
* testsuite/ld-powerpc/abs32-pie.r,
* testsuite/ld-powerpc/abs32-reloc.s,
* testsuite/ld-powerpc/abs32-shared.d,
* testsuite/ld-powerpc/abs32-shared.r,
* testsuite/ld-powerpc/abs32-static.d,
* testsuite/ld-powerpc/abs32-static.r: New tests.
* testsuite/ld-powerpc/powerpc.exp: Run them.
