| Age | Commit message (Collapse) | Author | Files | Lines |
|---|
|
After test-case gdb.mi/mi-break.exp, a gdb instance is left running.
The test-case starts two instances using mi_clean_restart, one using
separate-mi-tty.
For each instance, gdb_exit is called once, from two different locations:
- mi_clean_restart, and
- gdb_finish.
But this doesn't seem to be effective for the separate-mi-tty case.
Fix this by calling gdb_mi_exit at the end of proc test_break.
Likewise in a few more more test-case.
Tested on x86_64-linux.
Approved-By: Tom Tromey <tom@tromey.com>
PR testsuite/32709
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32709
|
|
In his review of my recent checkpoint work (commit e5501dd4321),
Andrew Burgess suggested that I use GDB's structured table generation
mechanism for the "info checkpoints" command. This patch does
that.
Andrew also recommended using print_stack_frame() for the "Frame"
column. I tried this, but ran into some problems, which are described
in a comment in the code. I got it to mostly work, except for the
case when the current/active fork is running. Switching context away
from and then back to a running fork doesn't work. It could, perhaps,
be made to work, but I'm not convinced that the checkpoint facility is
important enough to expend the effort for this case. So, instead,
I simply adapted the existing checkpoint frame printing code to
use the ui_out machinery instead of gdb_printf.
Approved-By: Tom Tromey <tom@tromey.com>
|
|
We currently check the TERM environment variable any time we call one
of the ui_file::can_emit_style_escape() functions. This seems
excessive.
During GDB's startup we also check for the NO_COLOR environment
variable and disable styling if this is set.
I propose that we combine these two checks, and perform them just once
during startup (as the current NO_COLOR check is currently done). As
with the NO_COLOR check, if the TERM variable is set to "dumb"
indicating that styling is not supported then we should just set
cli_styling to false.
This does mean that the user can then 'set style enabled on', even for
a dumb terminal, which was not possible previously. Before this
commit the "dumb" terminal check was separate and would prevent
styling even if 'set style enabled on' was in effect.
Of course, trying to turn on styling in a dumb terminal might not give
the results that a user hope for. And so, I have implemented a check
in `set_style_enabled`, so in a dumb terminal a user will see this:
(gdb) set style enabled on
warning: The current terminal doesn't support styling. Styled output might not appear as expected.
After which GDB will try to emit styling. We could, potentially,
prevent styling being enabled instead of emitting a warning, but I'm
inclined to let the user turn on styling if they really want to.
Approved-By: Kevin Buettner <kevinb@redhat.com>
Acked-By: Tom Tromey <tom@tromey.com>
|
|
Currently the TUI's asm window uses `source_styling` to control
styling. This setting is supposed to be for styling of source files
though, and the asm window displays disassembler output.
We have a different setting for this `disassemble_styling`, which is
controlled with 'set style disassembler enabled on|off'.
Switch to use the correct control variable.
I've written a new test for this, but this required some additions to
the tuiterm library in order to grab character attributes for a screen
region.
Approved-By: Tom Tromey <tom@tromey.com>
|
|
The help text for 'set/show style disassembler enable' was output of
date. It talks about GDB requiring the Python Pygments library, but
for many common architectures this is no longer the case, libopcode is
used for styling.
The Python Pygments library is still used as a fallback for those
architectures that libopcode doesn't currently style.
I've updated the help text to try and explain all this. The manual
was already updated.
Approved-By: Eli Zaretskii <eliz@gnu.org>
|
|
Here ( https://sourceware.org/gdb/current/onlinedocs/gdb.html/Signals.html ) I
read:
...
GDB has the ability to detect any occurrence of a signal in your program. You
can tell GDB in advance what to do for each kind of signal.
...
However, here ( https://man7.org/linux/man-pages/man2/ptrace.2.html ) I read:
...
While being traced, the tracee will stop each time a signal is
delivered, even if the signal is being ignored. (An exception is
SIGKILL, which has its usual effect.)
...
So, it seems to be that for SIGKILL we can't tell GDB in advance what to do.
Fix the documentation to reflect this.
Approved-By: Eli Zaretskii <eliz@gnu.org>
PR gdb/32714
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32714
|
|
For the Rust language, to avoid segmentation fault in case of an empty
array, do not try to copy any elements, but allocate and return
the empty array immediately.
With the command before the change, gdb crashes with message:
(gdb) set lang rust
(gdb) p [1;0]
Fatal signal: Segmentation fault
After the fix in this commit, gdb shows following message:
(gdb) set lang rust
(gdb) p [1;0]
$1 = []
Update the existing test case gdb.rust/expr.exp to verify the change.
Approved-By: Tom Tromey <tom@tromey.com>
|
|
or -R options and no regular relocs are present.
PR 32459
|
|
"Check we have ..." --> "Check if we have ..."
This is for consistency with the previous comment and
the code downstream.
|
|
For background reading, please see the previous patch, and the patch
before that!
After the last two patches, internal breakpoints can now be marked as
shlib_disabled if the library in which they are placed is unloaded.
The patch before last discusses a situation related to the
gdb.base/nostdlib.exp test, when run on a GNU/Linux glibc based system
where executables are compiled as PIE by default.
In this case it is observed that the dynamic linker will actually
report itself as unloaded (i.e. remove itself from the list of
currently loaded shared libraries). This behaviour is likely a bug in
the dynamic linker, but this behaviour exists in released versions of
the dynamic linker, so GDB should (if the cost is not too great) be
changed to handle this situation.
This commit handles a problem with the 'maint info breakpoints'
command.
When the dynamic linker is unloaded the 'shlib event' breakpoint is
marked as shlib_disabled (i.e. placed into the pending state). When
displaying the breakpoint in the 'maint info breakpoints' output, GDB
will try to print the locspec (location_spec *) as a string
Unfortunately, the locspec will be nullptr as the internal breakpoints
are not created via a location_spec, this means that GDB ends up
trying to call location_sepc::to_string() on a nullptr, resulting in
undefined behaviour (and a crash).
For most internal breakpoint types this is not a problem. If we
consider bp_longjmp_master for example, if the shared library
containing a breakpoint of this type is unloaded then first GDB marks
the breakpoint as shlib_disabled, then after unloading the shared
library breakpoint_re_set is called, which will delete the internal
breakpoint, and then try to re-create it (if needed). As a result,
the user never gets a change to run 'maint info breakpoints' on a
bp_longjmp_master breakpoint in the shlib_disabled state.
But bp_shlib_event and bp_thread_event breakpoints are not deleted and
recreated like this (see internal_breakpoint::re_set), so it is
possible, in rare cases, that we could end up trying to view one of
these breakpoint in a shlib_disabled state, and it would be nice if
GDB didn't crash as a result.
I've updated the printing code to check for and handle this case, and
I've updated the docs to mention this (rare) case.
For testing, I've extended gdb.base/nostdlib.exp to compile as
pie and nopie, and then run 'maint info breakpoints'. If we're
running on a buggy glibc then this will trigger the crash. I don't
know how I can trigger this problem without a buggy glibc as this
would require forcing the dynamic linker to be unloaded.
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
Approved-By: Tom Tromey <tom@tromey.com>
|
|
Bug PR gdb/32079 highlights an issue where GDB will try to remove a
breakpoint for a shared library that has been unloaded. This will
trigger an error from GDB like:
(gdb) next
61 dlclose (handle[dl]);
(gdb) next
warning: error removing breakpoint 0 at 0x7ffff78169b9
warning: error removing breakpoint 0 at 0x7ffff7730b57
warning: error removing breakpoint 0 at 0x7ffff7730ad3
54 for (dl = 0; dl < 4; ++dl)
(gdb)
What happens is that as the inferior steps over the dlclose() call,
GDB notices that the library has been unloaded and calls
disable_breakpoints_in_unloaded_shlib. However, this function only
operates on user breakpoints and tracepoints.
In the example above what is happening is that the test loads multiple
copies of libc into different linker namespsaces. When we 'next' over
the dlclose call one of the copies of libc is unloaded. As GDB placed
longjmp master breakpoints within the copy of libc that was just
unloaded, the warnings we see are GDB trying (and failing) to remove
these breakpoints.
I think the solution is for disable_breakpoints_in_unloaded_shlib to
handle all breakpoints, even internal ones like the longjmp master
breakpoints.
If we do this then the breakpoint will be marked as shlib_disabled and
also will be marked as not inserted. Later when we call
breakpoint_re_set() and the longjmp breakpoints are deleted we will no
longer try to remove them.
This solution is inspired by a patch suggested in the bug report:
https://sourceware.org/bugzilla/show_bug.cgi?id=32079#c3
There are some differences with my approach compared to the patch
suggested in the bug. First I have no need to delete the breakpoint
inside disable_breakpoints_in_unloaded_shlib as an earlier patch in
this series arranged for breakpoint_re_set to be called when shared
libraries are removed. Calling breakpoint_re_set will take care of
deleting the breakpoint for us. For details see the earlier commit
titled:
gdb: fixes for code_breakpoint::disabled_by_cond logic
Next, rather than only handling bp_longjmp and bp_longjmp_master, I
allow all breakpoints to be handled. I also only give the warning
about disabling breakpoints for user breakpoints, I don't see the
point of warning the user about internal b/p changes.
With this done the issues in PR gdb/32079 are resolved.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32079
Tested-By: Hannes Domani <ssbssa@yahoo.de>
Approved-By: Tom Tromey <tom@tromey.com>
|
|
This commit removes the clearing of bp_location::inserted from
disable_breakpoints_in_unloaded_shlib, my claim is that this call is
not needed (any more), and with the next commit, this line actually
causes some problems.
The disable_breakpoints_in_unloaded_shlib function was added back in
2004 with commit 84acb35a5a97c, and from this first version the
function cleared the bp_location::inserted flag. The motivation for
this is that the shared library might have already been unmapped, in
which case, a later attempt to remove the location could fail.
In 2013 a similar function disable_breakpoints_in_freed_objfile was
added. This function also cleared bp_location::inserted for similar
reasons. This code was added in commit:
commit 63644780babdca3f40e1978a236b6cd78473c91b
Date: Tue Mar 12 11:10:18 2013 +0100
New remove-symbol-file command.
Then in 2014 the clearing of bp_location::inserted was removed from
disable_breakpoints_in_freed_objfile in the commit:
commit 08351840eabb44799e3d01026610420758f4fa40
Date: Tue Apr 22 23:19:19 2014 +0100
Stale breakpoint instructions, spurious SIGTRAPS.
The reason that clearing the ::inserted flag was removed in this
commit is that if the disable_breakpoints_in_freed_objfile function
was called when the b/p were actually inserted, and the memory for the
associated objfile wasn't actually unmapped, then we could end up
leaving breakpoints inserted into the inferior, which leads to
spurious SIGTRAPs.
In the next commit I'll change disable_breakpoints_in_unloaded_shlib
so that all breakpoints, not just user breakpoints, will be
disabled (via shlib_disabled) when a shared library is unloaded. This
addresses PR gdb/32079, see the next commit for a fuller justification
for this change.
The problem is that when I tested the next commit I ran into some
regressions from the gdb.base/nostdlib.exp test when run on an AArch64
GNU/Linux system where executables are compiled as PIE by default.
This test compiles a simple binary with the -nostdlib flag.
What happens is this:
- The executable is compiled as PIE, this means that we get a
dynamically linked executable, the dynamic linker is used to
perform the PIE relocation, but the executable uses no other
shared libraries.
- When GDB starts the inferior, initially the dynamic linker is
discovered as a shared library being used by the application, GDB
loads in the library and its debug symbols, placing the internal
"shlib event" breakpoints so that future shared library events can
be tracked.
- For the target I tested on systemtap probes were not used, instead
GDB fell back to the old style even breakpoint.
- As the inferior progresses, after the PIE relocation has been
performed, the dynamic linker performs some house keeping on the
list of shared libraries being used by the application. During
this process the dynamic linker is removed from the list of shared
libraries being used by the inferior, this causes GDB see a shared
library event, which GDB understands to mean that it should unload
the dynamic linker from the inferior.
I spoke with the glibc engineers at RH, and the feeling is that
this is likely a bug (it's still being investigated). But I don't
think it really matters if this is a bug or not. There are
versions of glibc in the wild that have this behaviour, so GDB
should (if the cost is not too great) be updated to handle this.
Obviously after removing the dynamic linker from the list of
shared libraries, the dynamic linker is not actually unmapped,
that would not be possible, it's the dynamic linker that does the
unmapping, so the dynamic linker is left mapped into the
inferior's address space.
- With the next patch in place all breakpoints (user and internal)
within the dynamic linker are disabled (shlib_disabled) and
currently marked as not inserted (bp_location::inserted flag is
cleared).
- Having processed the shared library event GDB then resumes the
inferior. As the shared library event is not a full stop of the
inferior (i.e. we don't remove all breakpoints before handling the
event), all of the breakpoints in the dynamic linker are still
inserted, but are now marked as not-inserted.
- GDB then resumes the inferior and immediately hits the breakpoint
that is still inserted. As GDB thinks this breakpoint is not
inserted, this is reported to the user as a SIGTRAP.
The fix I think is just to not clear the bp_location::inserted flag in
disable_breakpoints_in_unloaded_shlib. This will leave the breakpoint
as inserted in the case above. GDB will now be able to successfully
resume the inferior after the shared library event (knowing there is a
breakpoint inserted GDB will step over it and continue as expected).
The next time the inferior performs a full stop the now shlib_disabled
breakpoint will be removed from the inferior we would want.
For the usual case, where a shared library is being unloaded due to
say a dlclose, the breakpoints in the library will be marked as
disabled, but will be left inserted. The next time remove_breakpoints
is called GDB will try to remove those breakpoint locations. If the
removal fails, as the breakpoint is marked shlib_disabled, GDB will
hide the error message from the user and just assume that the shared
library has been unmapped. This functionality was first added in 2008
in commit 879d1e6b4674bc8.
There are two aspects to testing this change. First whether no
clearing the ::inserted flag causes general problems. That is tested
by running the full testsuite (I see no regressions).
Then there is the specific problem that caused me to make this
change. That issue only occurs on AArch64, with GNU/Linux using
glibc, when the executable is compiled as PIE, and doesn't use any
shared libraries other than the dynamic linker (which can be the
gdb.base/nostdlib.exp test if run on the right system). What I don't
know is how to recreate this setup in a more general form.
We can't use add-symbol-file/remove-symbol-file as that passes through
disable_breakpoints_in_freed_objfile instead, which the ::installed
flag is already not adjusted.
Also the bug doesn't trigger on x86 targets due to code in
handle_signal_stop which sees the inserted breakpoint, and decides
this must be a breakpoint that actually exists in the program, and
then because gdbarch_decr_pc_after_break returns non-zero for x86, GDB
steps the inferior past the breakpoint. This is the big difference
from AArch64 where gdbarch_decr_pc_after_break returns zero, and so
the inferior gets stuck hitting the unexpectedly inserted breakpoint.
Approved-By: Tom Tromey <tom@tromey.com>
|
|
While working on the previous commit I realised that GDB would not
handle dprintf breakpoints correctly when a shared library was
unloaded.
Consider this example using the test binary from shlib-unload.exp. In
the function 'foo' we create a dprintf is in a shared library:
(gdb) b 59
Breakpoint 1 at 0x401215: file /tmp/projects/binutils-gdb/build/gdb/testsuite/../../../src/gdb/testsuite/gdb.base/shlib-unload.c, line 59.
(gdb) r
Starting program: /tmp/projects/binutils-gdb/build/gdb/testsuite/outputs/gdb.base/shlib-unload/shlib-unload
Breakpoint 1, main () at /tmp/projects/binutils-gdb/build/gdb/testsuite/../../../src/gdb/testsuite/gdb.base/shlib-unload.c:59
59 res = dlclose (handle); /* Break here. */
(gdb) dprintf foo,"In foo"
Dprintf 2 at 0x7ffff7fc50fd: file /tmp/projects/binutils-gdb/build/gdb/testsuite/../../../src/gdb/testsuite/gdb.base/shlib-unload-lib.c, line 23.
(gdb) n
Error in re-setting breakpoint 2: Function "foo" not defined.
warning: error removing breakpoint 2 at 0x7ffff7fc50fd
warning: error removing breakpoint 2 at 0x7ffff7fc50fd
warning: error removing breakpoint 2 at 0x7ffff7fc50fd
warning: error removing breakpoint 2 at 0x7ffff7fc50fd
warning: error removing breakpoint 2 at 0x7ffff7fc50fd
warning: error removing breakpoint 2 at 0x7ffff7fc50fd
warning: error removing breakpoint 2 at 0x7ffff7fc50fd
warning: error removing breakpoint 2 at 0x7ffff7fc50fd
Cannot remove breakpoints because program is no longer writable.
Further execution is probably impossible.
60 assert (res == 0);
(gdb)
What happens here is that as the inferior steps over the dlclose call
the shared library containing 'foo' is unloaded and
disable_breakpoints_in_unloaded_shlib is called. However in
disable_breakpoints_in_unloaded_shlib we have this check:
if (b.type != bp_breakpoint
&& b.type != bp_jit_event
&& b.type != bp_hardware_breakpoint
&& !is_tracepoint (&b))
continue;
As the dprintf has type bp_dprintf then this check triggers and we
ignore the dprintf, meaning the dprintf is not disabled. When the
inferior stops after the 'next' GDB tries to remove all breakpoints
but the dprintf can no longer be removed, the memory in which it was
placed has been unmapped from the inferior.
The fix is to start using is_breakpoint() in
disable_breakpoints_in_unloaded_shlib instead of the bp_breakpoint and
bp_hardware_breakpoint checks. The is_breakpoint() function also
checks for bp_dprintf.
With this fix in place GDB now correctly disables the breakpoint and
we no longer see the warning about removing the breakpoint.
During review it was pointed out that PR gdb/23149 and PR gdb/20208
both describe something similar, though for these bugs, the inferior
is restarted (which unloads all currently loaded shlib) rather than
passing over the dlclose. But the consequences are pretty similar.
I've included a test which covers this case.
One additional thing that these two bugs did show though is that
disable_breakpoints_in_shlibs also needs to start using is_breakpoint
for the same reason. Without this change, when an inferior is
restarted we get a warning like this for dprintf breakpoints:
warning: Temporarily disabling breakpoints for unloaded shared library "..."
but we don't get a similar warning for "normal" breakpoints. This is
because disable_breakpoints_in_shlibs is called from clear_solib,
which is called when an inferior is restarted.
It is best not to think too hard about disable_breakpoints_in_shlibs,
as this function is pretty broken, e.g. it doesn't call
notify_breakpoint_modified, despite modifying the breakpoints. But
for now I'm ignoring that, but fixing this is definitely on my list
for my next set of breakpoint related fixes, it's just that a lot of
these breakpoint fixes end up being depending on one another, but I
want to avoid making this series too long. So for now, I'm ignoring
the existing bug (missing breakpoint modified events), and fixing
disable_breakpoints_in_shlibs to cover dprintf.
With these fixes in place, the two bugs mentioned above should be
fixed.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=23149
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=20208
Tested-By: Hannes Domani <ssbssa@yahoo.de>
Approved-By: Tom Tromey <tom@tromey.com>
|
|
This commit rewrites disable_breakpoints_in_unloaded_shlib to be more
like disable_breakpoints_in_freed_objfile. Instead of looping over
all b/p locations, we instead loop over all b/p and then over all
locations for each b/p.
The advantage of doing this is that we can fix the small bug that was
documented in a comment in the code:
/* This may cause duplicate notifications for the same breakpoint. */
notify_breakpoint_modified (b);
By calling notify_breakpoint_modified() as we modify each location we
can potentially send multiple notifications for a single b/p.
Is this a bug? Maybe not. After all, at each notification one of the
locations will have changed, so its probably fine. But it's not
ideal, and we can easily do better, so lets do that.
There's a new test which checks that we only get a single notification
when the shared library is unloaded. Note that the test is written as
if there are multiple related but different tests within the same test
file ... but there aren't currently! The next commit will add another
test proc to this test script at which point the comments will make
sense. I've done this to avoid unnecessary churn in the next commit.
Tested-By: Hannes Domani <ssbssa@yahoo.de>
Approved-By: Tom Tromey <tom@tromey.com>
|
|
I spotted that the code_breakpoint::disabled_by_cond flag doesn't work
how I'd expect it too. The flag appears to be "sticky" in some
situations; once a code_breakpoint::disabled_by_cond flag is marked
true, then, in some cases the flag wont automatically become false
again, even when you'd think it should.
The problem is in update_breakpoint_locations. In this function,
which is called as a worker of code_breakpoint::re_set, GDB computes a
new set of locations for a breakpoint, the new locations are then
installed into the breakpoint.
However, before installing the new locations GDB attempts to copy the
bp_location::enabled and bp_location::disabled_by_cond flag from the
old locations into the new locations.
The reason for copying the ::enabled flag makes sense. This flag is
controlled by the user. When we create the new locations if GDB can
see that a new location is equivalent to one of the old locations, and
if the old location was disabled by the user, then the new location
should also be disabled.
However, I think the logic behind copying the ::disabled_by_cond flag
is wrong. The disabled_by_cond flag is controlled by GDB and should
toggle automatically. If the condition string can be parsed then the
flag should be false (b/p enabled), if the condition string can't be
parsed then the flag should be true (b/p disabled).
As we always parse the condition string in update_breakpoint_locations
before we try to copy the ::enabled flag value then the
::disabled_by_cond flag should already be correct, there's no need to
copy over the ::disabled_by_cond value from the old location.
As a concrete example, consider a b/p placed within the main
executable, but with a condition that depends on a variable within a
shared library.
When the b/p is initially created the b/p will be disabled as the
condition string will be invalid (the shared library variable isn't
available yet).
When the inferior starts the shared library is loaded and the
condition variable becomes available to GDB. When the shared library
is loaded breakpoint_re_set is called which (eventually) calls
update_breakpoint_locations.
A new location is computed for the breakpoint and the condition string
is parsed. As the shared library variable is now know the expression
parses correctly and ::disabled_by_cond is left false for the new
location.
But currently GDB spots that the new location is at the same address
as the old location and copies disabled_by_cond over from the old
location, which marks the b/p location as disabled. This is not what
I would expect.
The solution is simple, don't copy over disabled_by_cond.
While writing a test I found another problem though. The
disabled_by_cond flag doesn't get set true when it should! This is
the exact opposite of the above.
The problem here is in solib_add which is (despite the name) called
whenever the shared library set changes, including when a shared
library is unloaded.
Imagine an executable that uses dlopen/dlclose to load a shared
library. Given an example of a b/p in the main executable that has a
condition that uses a variable from our shared library, a library
which might be unloaded with dlclose.
My expectation is that, when the library is unloaded, GDB will
automatically mark the breakpoint as disabled_by_cond, however, this
was not happening.
The problem is that in solib_add we only call breakpoint_re_set when
shared libraries are added, not when shared libraries are removed.
The solution I think is to just call breakpoint_re_set in both cases,
now the disabled_by_cond flag is updated as I'd expect.
Unfortunately, making this change causes a regression when running:
make check-gdb \
TESTS="gdb.trace/change-loc.exp" \
RUNTESTFLAGS="--target_board=native-gdbserver"
This test unloads a shared library and expects breakpoints within the
shared library to enter the PENDING state (because the bp_location's
shlib_disabled flag will be set). However, the new call to
breakpoint_re_set means that this is no longer the case.
The breakpoint_re_set call means that update_breakpoint_locations is
called, which then checks if all locations for a breakpoint are
pending or not. In this test not all locations are pending, and so
GDB recalculates the locations of each breakpoint, this means that
pending locations are discarded.
There is a but report PR gdb/32404 which mentions the problems with
shlib_disabled pending breakpoints, and how they are prone to being
randomly deleted if the user can cause GDB to trigger a call to
breakpoint_re_set. This patch just adds another call to
breakpoint_re_set, which triggers this bug in this one test case.
For now I have marked this test as KFAIL. I do plan to try and
address the pending (shlib_disabled) breakpoint problem in the future,
but I'm not sure when that will be right now.
There are, of course, tests to cover all these cases.
During review I was pointed at bug PR gdb/32079 as something that this
commit might fix, or help in fixing.
And this commit is part of the fix for that bug, but is not the
complete solution. However, the remaining parts of the fix for that
bug are not really related to the content of this commit.
The problem in PR gdb/32079 is that the inferior maps multiple copies
of libc in different linker namespaces using dlmopen (actually libc is
loaded as a consequence of loading some other library into a different
namespace, but that's just a detail). The user then uses a 'next'
command to move the inferior forward.
GDB sets up internal breakpoints on the longjmp symbols, of which
there are multiple copies (there is a copy in every loaded libc).
However, the 'next' command is, in the problem case, stepping over a
dlclose call which unloads one of the loaded libc libraries.
In current HEAD GDB in solib_add we fail to call breakpoint_re_set()
when the library is unloaded; breakpoint_re_set() would delete and
then recreate the longjmp breakpoints. As breakpoint_re_set() is not
called GDB thinks that the the longjmp breakpoint in the now unloaded
libc still exists, and is still inserted.
When the inferior stops after the 'next' GDB tries to delete and
remove the longjmp breakpoint which fails as the libc in which the
breakpoint was inserted is no longer mapped in.
When the user tries to 'next' again GDB tries to re-insert the still
existing longjmp breakpoint which again fails as the memory in which
the b/p should be inserted is no longer part of the inferior memory
space.
This commit helps a little. Now when the libc library is unmapped GDB
does call breakpoint_re_set(). This deletes the longjmp breakpoints
including the one in the unmapped library, then, when we try to
recreate the longjmp breakpoints (at the end of breakpoint_re_set) we
don't create a b/p in the now unmapped copy of libc.
However GDB does still think that the deleted breakpoint is inserted.
The breakpoint location remains in GDB's data structures until the
next time the inferior stops, at which point GDB tries to remove the
breakpoint .... and fails.
However, as the b/p is now deleted, when the user tries to 'next' GDB
no longer tries to re-insert the b/p, and so one of the problems
reported in PR gdb/32079 is resolved.
I'll fix the remaining issues from PR gdb/32079 in a later commit in
this series.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32079
Tested-By: Hannes Domani <ssbssa@yahoo.de>
Approved-By: Tom Tromey <tom@tromey.com>
|
|
|
|
I noticed a spot in dwarf2/index-write.c that was mis-formatted. This
fixes it.
|
|
Format mips-tdep.c code as described on links:
https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards
https://www.gnu.org/prep/standards/standards.html#Comments
correcting indentation as required.
Approved-by: Kevin Buettner <kevinb@redhat.com>
Approved-by: Maciej W. Rozycki <macro@orcam.me.uk>
|
|
Format mips-tdep.c code as described on links:
https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards
https://www.gnu.org/prep/standards/standards.html#Comments
converting spaces to tabs and fixing alignment as appropriate.
Approved-by: Kevin Buettner <kevinb@redhat.com>
Approved-by: Maciej W. Rozycki <macro@orcam.me.uk>
|
|
Format mips-tdep.c code as described on links:
https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards
https://www.gnu.org/prep/standards/standards.html#Comments
capitalizing sentences and adding full stops and spaces after them.
Approved-by: Kevin Buettner <kevinb@redhat.com>
Approved-by: Maciej W. Rozycki <macro@orcam.me.uk>
|
|
Format mips-tdep.c code as described on links:
https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards
https://www.gnu.org/prep/standards/standards.html#Comments
removing and adding new lines as appropriate.
Approved-by: Kevin Buettner <kevinb@redhat.com>
Approved-by: Maciej W. Rozycki <macro@orcam.me.uk>
|
|
Format mips-tdep.c code as described on links:
https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards
https://www.gnu.org/prep/standards/standards.html#Comments
removing trailing space.
Approved-by: Kevin Buettner <kevinb@redhat.com>
Approved-by: Maciej W. Rozycki <macro@orcam.me.uk>
|
|
The oss-fuzz gas fuzzer is quite broken in that it doesn't
reinitialise all gas and bfd static variables between runs. Since gas
naughtily modifies bfd_und_section and bfd_abs_section those bfd
statics can hold pointers into freed memory between runs.
This patch fixes oss-fuzz issue 398060144.
|
|
tic4x-coff and mcore-pe tickle this bug by a peculiarity of their
default ld scripts.
PR 32731
* ldlang.c (lang_add_wild): Init filenames_reversed when no
filespec.
|
|
|
|
Add gpr and fpr names for the o64 ABI to objdump.
With the recent addition of both EABIs, this completes support for the
standard ABI options (ABI-breaking options such as -modd-spreg or
-mabi=32 -mfp64 notwithstanding). The names have been verified against
GCC's usage of the registers. Notably, the only(?) documentation that
defines the o64 ABI at
https://gcc.gnu.org/projects/mipso64-abi.html
appears to contain a mistake w.r.t. floating-point arguments. In
particular:
> If the first and second arguments floating-point arguments to a
> function are 32-bit values, they are passed in $f12 and $f14.
As from 4.0.0 this does not happen in GCC's implementation of the ABI;
a pair of single-float arguments are still passed in $f12 and $f13, the
same as when one or both of the arguments are double-precision floats.
The registers $f12, $f13 and $f14 have been named $fa0, $fa1 and $ft10
to match the implementation.
Signed-off-by: Maximilian Ciric <max.ciric@gmail.com>
|
|
|
|
gdb/testsuite/rocm.exp: Use system GPU(s) to detect features
Background
----------
This patch revisits the purpose of hcc_amdgpu_targets{} in
order to address the separation of concerns between:
- GPU targets passed to the compiler. This kind of target
is passed as an argument to flags like "--offload-arch=...",
"--targets=...", etc.
- GPU targets as in available GPU devices on the system. This
is crucial for finding which capabilities are available,
and therefore which tests should be executed or skipped.
Code change
-----------
- A new "find_amdgpu_devices{}" procedure is added. It is
responsible for listing the GPU devices that are available
on the system.
- "hcc_amdgpu_targets{}" is rewritten to use the newly added
"find_amdgpu_devices{}" when there's no environment variable
(HCC_AMDGPU_TARGET) set.
- The output of "hcc_amdgpu_targets{}" is now only used in
places that set the target for the building toolchains.
- The output of "find_amdgpu_devices{}" is used anywhere that
needs to evaluate the GPU features.
Approved-By: Lancelot Six <lancelot.six@amd.com> (amdgpu)
Change-Id: Ib11021dbe674aa40192737ede78284a1bc531513
|
|
After I found his email bouncing, Stan, via private communication which
Nick helped with, has indicated that - having retired - he won't any
longer fulfill the maintainer role here.
|
|
Make md_undefined_symbol() conditional upon dealing with ELF, much like
other architectures (e.g. Arm32 and Arm64) have it. This avoids errors
in gas and even assertions in libbfd when "accidentally" e.g. a COFF-
targeting source file uses "_GLOBAL_OFFSET_TABLE_" for whatever reason.
While there also convert the final return statement to properly use
NULL.
NB: In principle 64-bit Mach-O knows GOT, too. Yet only an i?86-macho
assembler can be built right now, as per configure.tgt. Pretty clearly
adjustments to gotrel[] would also be necessary before these targets
could actually work reasonably cleanly.
|
|
A few lines up we would have already bailed when "baseless && is_pic".
|
|
The ELF linker rejects use of this reloc type without a base register
for PIC code. Suppress its use by gas in such cases.
To keep things building for non-ELF, include the entire containing if()
in an #ifdef: All consumers of ->fx_tcbit* live in such conditionals as
well, hence there's no reason to keep the producer active.
|
|
REX2.M affects what insn we're actually dealing with, so we better check
this to avoid transforming (future) insns we must not touch.
|
|
With us doing the transformation to an immediate operand for MOV and
various ALU insns, there's little reason to then not support the same
conversion for the other two insns which have respective immediate
operand forms. Unfortunately for IMUL (due to the 0F opcode prefix)
there's no suitable relocation, so the pre-APX forms cannot be marked
for relaxation in the assembler.
|
|
H.J. requested this adjustment; I'm unaware of any specific technical
background.
|
|
Just like was done recently for x86-64 (commit 4998f9ea9d35): Even if
the assembler avoids using the relaxable relocation for inapplicable
insns, the relocation type can still appear for other reasons. Be more
thorough in the opcode checking we do, to avoid bogusly altering other
insns.
Furthermore correct an opcode mask (even if with the added condition
that's now fully benign).
|
|
|
|
The part "... this command by default creates it produces a single ..."
sounds wrong. Replace with "... this command by default produces a
single ...".
Change-Id: I39cc533fa5a2bf473ca9e361ee0e6426d7d37ac6
|
|
Today I learned that, at least on my system (Fedora 40), the printf
"%#x" format will produce "0" rather than "0x0" when given 0 as an
argument.
This causes dwarf-mode.el to not correctly fontify the very first
"Compilation Unit" line it sees.
This patch adapts dwarf-mode.el. As always, this patch bumps the
version number for easier installation.
I am checking this in.
|
|
Change-Id: Ibd8d6c35c2cc02e309f83b11b5fd1172dfa05283
|
|
clang 19 fails to build gdb with this error:
/home/simark/src/binutils-gdb/gdb/compile/compile-object-load.c:302:3: error: cannot initialize a member subobject of type 'void (*)(const char *, ...) __attribute__((noreturn))' with an lvalue of type 'void (const char *, ...)'
302 | link_callbacks_einfo, /* einfo */
| ^~~~~~~~~~~~~~~~~~~~
This illustrates that the bfd_link_callbacks array is missing an entry
for the "fatal" callback, add it.
The fatal field was added very recently, in d26161914 ("PR 32603, more
ld -w misbehaviour"). We're lucky that the new callback was marked with
the noreturn attribute and that clang checks that, otherwise this would
have gone unnoticed.
Change-Id: I68b63d89f2707359e6254da23bdc0776b0e03ba2
|
|
While working on another series, I discovered that the existing code
in gdb.ada/complete.exp that conditionally accepts a completion does
not work correctly. The code assumes that wrapping a line in "(...)?"
will make the entire line optional, but really this will only match a
blank line.
Meanwhile, I needed this same patch for a second series I'm working
on, so I've pulled this out. As it only affects Ada, I am going to
check it in.
|
|
I noticed a non-bool-like use of target_get_tib_address in
windows-tdep.c. After fixing this I thought it would be good to
document the target method; and this also lead to some non-bool-like
commentary in remote.c. This patch fixes all of these nits.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
|
|
Now that stabs is deprecated, we should probably warn our users of it
before removing support, so that they have time to react and either make
themselves heard, or fix things on their end so that they can still debug
their applications.
This commit adds a new function that emits a warning whenever GDB does
stabs reading. Since there are several places where stabs is
re-invented, this warning had to be added to many places, but I think I
managed to warn everywhere relevant without duplicating warnings.
Also, the test gdb.stabs/weird.exp explicitly checks for GDB warnings
when reading stabs, so it had to be updated to account for the
deprecation warning. It is done generically, since it will be removed in
the next release anyway.
Approved-By: Tom Tromey <tom@tromey.com>
|
|
pr30117 showed one of the assertions added by 4d1bb7955a8b was too
strict. oss-fuzz also found the second assertion to be too strict,
with this testcase distilled from 7k of garbage source:
A=%eax%%!
Y=A
Z=A
or $6,Z
PR 32721
* config/tc-i386.c (parse_register): Move "know" into
condition. Simplify.
|
|
Right now, cooked_index_functions::expand_symtabs_matching computes
the language for each component of a split name, using the language of
the corresponding entry.
Instead, I think that we want to do all the comparisons using the
final entry's language. I don't think there's a way to trigger bad
behavior here right now, but with another series I'm working on, we
end up with some entries whose language can't reliably be determined;
and in this case using the final entry's language avoids issues.
I suspect we could also dispense with the per-segment name-matcher
lookup as well.
|
|
This changes the various producer-checking functions to be methods on
dwarf2_cu. It adds a few new caching members as well -- every one
that could reasonably be done this way has been converted, with the
only exception being a gdbarch hook.
Note the new asserts in the accessors. Without the earlier
prepare_one_comp_unit change, these could trigger in some modes.
|
|
This changes prepare_one_comp_unit to be a private method of
cutu_reader. This should make it somewhat simpler to reason about.
|
|
Currently, prepare_one_comp_unit is called somewhat haphazardly: it is
mostly called when a CU is read, but some places manage to instantiate
a cutu_reader* without calling it, and some code (e.g.,
read_file_scope) calls it without really needing to.
Aside from contributing to the general confusion around CU reading,
this doesn't really cause problems in the current tree. However, it
is possible for the DWARF reader to check the CU's producer before it
is ever set -- which is certainly unintended.
|
|
This moves the producer_is_realview to producer.c.
|
