Summary:
On arm64, linux<=4.4 and Android<=M there is a bug, which prevents single-stepping from working when
the system comes back from suspend, because of incorrectly initialized CPUs. This did not really
affect Android<M, because it did not use software suspend, but it is a problem for M, which uses
suspend (doze) quite extensively. Fortunately, it seems that the first CPU is not affected by
this bug, so this commit implements a workaround by forcing the inferior to execute on the first
cpu whenever we are doing single stepping.
While inside, I have moved the implementations of Resume() and SingleStep() to the thread class
(instead of process).
Reviewers: tberghammer, ovyalov
Subscribers: aemerson, rengolin, tberghammer, danalbert, srhines, lldb-commits
Differential Revision: http://reviews.llvm.org/D17509
llvm-svn: 261636
Summary:
There was a bug in NativeProcessLinux, where doing an instruction-level single-step over the
thread-creation syscall resulted in loss of control over the inferior. This happened because
after the inferior entered the thread-creation maintenance stop, we unconditionally performed a
PTRACE_CONT, even though the original intention was to do a PTRACE_SINGLESTEP. This is fixed by
storing the original state of the thread before the stop (stepping or running) and then
performing the appropriate action when resuming.
I also get rid of the callback in the ThreadContext structure, which stored the lambda used to
resume the thread, but which was not used consistently.
A test verifying the correctness of the new behavior is included.
Reviewers: ovyalov, tberghammer
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D12104
llvm-svn: 245545
SUMMARY:
Last 3bits of the watchpoint address are masked by the kernel. For example, n is
at 0x120010d00 and m is 0x120010d04. When a watchpoint is set at m, then watch
exception is generated even when n is read/written. To handle this case, instruction
at PC is emulated to find the base address of the load/store instruction. This address
is then appended to the description of the stop-info packet. Client then reads this
information to check whether the user has set a watchpoint on this address.
Reviewers: jingham, clayborg
Subscribers: nitesh.jain, mohit.bhakkad, sagar, bhushan and lldb-commits
Differential Revision: http://reviews.llvm.org/D11672
llvm-svn: 244864
Summary:
This adds support for jstopinfo field of stop-reply packets. This field enables us to avoid
querying full thread stop data on most stops (see r242593 for more details).
Reviewers: ovyalov, clayborg
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D11415
llvm-svn: 242997
Summary:
Previously, we reported inferior receiving SIGSEGV (or SIGILL, SIGFPE, SIGBUS) as an "exception"
to LLDB, presumably to match OSX behaviour. Beside the fact that we were basically lying to the
user, this was also causing problems with inferiors which handle SIGSEGV by themselves, since
LLDB was unable to reinject this signal back into the inferior.
This commit changes LLGS to report SIGSEGV as a signal. This has necessitated some changes in the
test-suite, which had previously used eStopReasonException to locate threads that crashed. Now it
uses platform-specific logic, which in the case of linux searches for eStopReasonSignaled with
signal=SIGSEGV.
I have also added the ability to set the description of StopInfoUnixSignal using the description
field of the gdb-remote packet. The linux stub uses this to display additional information about
the segfault (invalid address, address access protected, etc.).
Test Plan: All tests pass on linux and osx.
Reviewers: ovyalov, clayborg, emaste
Subscribers: emaste, lldb-commits
Differential Revision: http://reviews.llvm.org/D10057
llvm-svn: 238549
This change reorganize the register read/write code inside lldb-server on Linux
with moving the architecture independent code into a new class called
NativeRegisterContextLinux and all of the architecture dependent code into the
appropriate NativeRegisterContextLinux_* class. As part of it the compilation of
the architecture specific register contexts are only compiled on the specific
architecture because they can't be used in other cases.
The purpose of this change is to remove a lot of duplicated code from the different
register contexts and to remove the architecture dependent codes from the global
NativeProcessLinux class.
Differential revision: http://reviews.llvm.org/D9935
llvm-svn: 238196
Summary:
Now that all thread events are processed synchronously, there is no need to have separate records
of whether a thread is running. This changes the (ever-dwindling) remains of the TSC to use
NativeThreadLinux as the authoritative source of the state of threads. The rest of the
ThreadContext we need has been moved to a member of NTL.
Test Plan: ninja check-lldb continues to pass
Reviewers: chaoren, ovyalov
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9562
llvm-svn: 236983
The following situation occured if we were stopping a process (due to breakpoint, watchpoint, ...
hit) while a new thread was being created.
- process has two threads: A and B.
- thread A hits a breakpoint: we send a STOP signal to thread B and register a callback with
ThreadStateCoordinator to send a stop notification after the thread stops.
- thread B stops, but not due to the SIGSTOP, but on a thread creation event (of a new thread C).
We are unaware of our desire to stop, so we queue ThreadStopped and RequestResume operations
with TSC, so the thread can continue running.
- TSC receives the ThreadStopped event, sees that all threads are stopped and fires the delayed
stop notification.
- immediately after that TSC gets the RequestResume operation, so it resumes the thread.
At this point the state is inconsistent because LLDB thinks the process is stopped and will start
issuing commands to it, but one of the threads is in fact running. Things eventually break.
I address this problem by omitting the two TSC events altogether and Resuming the thread B
directly. This way the short stop is invisible to the TSC and the delayed notification will not
fire. We will fire the notification when we actually process the SIGSTOP on thread B.
When we get the initial SIGSTOP for thread C, we also resume the thread and send a
ThreadWasCreated message (is_stopped = false) to the TSC. This way, the TSC can stop the thread
on its own and handle the stop event later. This way the state of the new thread is correctly
handled as well (thanks Chaoren for the idea).
This patch also removes the synchronisation between the thread creation notifications on threads
B and C. The need for this synchronisation is unclear (the comments seem to hint that the new
thread is "fully created" only after we process both events, but I have noticed no regressions in
treating it as "created" even after just processing the initial C event), but it is a source for
many kinds of obscure races, since it introduces a new thread state "Launching" and the rest of
the code does not handle this state at all (what happens if we get a resume request from LLDB
while this thread is launching? what happens if we get a stop request? etc.).
This fixes the "spurious $O packet" problem in TestPrintStackTraces.py. However, the test remains
disabled on i386 due to the VDSO issue.
Test Plan:
TestPrintStackTraces works on x86_64. No regressions in the rest of the test suite.
Reviewers: vharron, chaoren
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9145
llvm-svn: 235579
This patch is major step towards supporting lldb on ARM.
This adds all the required bits to support register manipulation on Linux Arm.
Also adds utility enumerations, definitions and register context classes for arm.
llvm-svn: 234870
Test Plan: No tests, this is just a debug logging function.
Reviewers: tberghammer
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D8453
llvm-svn: 232815
So that we don't have to update every single #include in the entire
codebase to #include this new header (which used to get included by
lldb-private-log.h, we automatically #include "Logging.h" from
within "Log.h".
llvm-svn: 232653
Some linux kernel reports a watchpoint hit after single stepping even
when no watchpoint was hit. This CL looks for a watchpoint which was hit
and reports a stop by trace if it haven't found any.
Differential revision: http://reviews.llvm.org/D8081
llvm-svn: 232482
Summary:
They'll be set anyway when the thread starts running, so the launching threads
should just ignore the set request.
Reviewers: ovyalov
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D7914
llvm-svn: 230671
Currently it is uses the same code used on linux. Will be replaced with
android specific code if needed.
Differential Revision: http://reviews.llvm.org/D7613
llvm-svn: 229371
* When the thread state coordinator is told to skip sending a stop request
for a running thread that is ignored (e.g. the thread that steps in a
step operation is technically running and should not have a stop sent
to it, since it will stop of its own accord per the kernel step operation),
ensure the deferred signal notification logic still waits for the
skipped thread. (i.e. we want to defer the notification until the
stepping thread is indeed stopped, we just don't want to send it a tgkill).
* Add ThreadStateCoordinator::RequestResumeAsNeeded(). This variant of the
RequestResume() method does not call the error function when the thread
is already running. Instead, it just logs that the thread is already
running and skips the resume operation. This is useful for the case of
vCont;c handling, where we tell all threads that they should be running.
At the place we're calling, all we know is "we want this thread running if
it isn't already," and that's exactly what this command does.
* Formatting change (minor) in NativeThreadLinux logging.
llvm-svn: 227913
Tracked down while working on https://github.com/tfiala/lldb/issues/75.
This is not a complete fix for that issue, but moves us farther along.
Fixes:
* When a thread step is requested via vCont:{s,S}, Resume() now marks
the stepping thread as (1) currently stepping and (2) does trigger
the deferred signal for the stepped thread. This fixes a bug where
we were actually triggering a deferred stop cycle here for the non-stepping
thread since the single step thread was not part of the Resume()
deferred signal mechanism. The stepping thread is also marked in
the thread state coordinator as running (via a resume callback).
* When we get the SIGTRAP signal for the step completion, we don't
do a deferred signal call - that happened during the vCont:{s,S}
processing in Resume() already. Now we just need to mark that
the stepping thread is now stopped. If this is the last thread
in the set that needs to stop, it will trigger the process/delegate
stop call that will notify lldb. Otherwise, that'll happen when
the final thead we're waiting for stops.
Misc:
* Fixed up thread stop logging to use a leading 0 (0x%PRIx32) so
we don't get log lines like 0x5 for 0x05 SIGTRAP.
llvm-svn: 227911
* Fixes the local stack variable return pointer usage in NativeThreadLinux::GetName().
* Changes NativeThreadProtocol::GetName() to return a std::string.
* Adds a unit test to verify thread names don't regress in the future. Currently only run on Linux since I know default thread names there.
llvm-svn: 217717
* Sends a SIGSTOP to the process.
* Fixes busted SIGSTOP handling. Now builds a list of non-stopped
that we wait for the PTRACE group-stop for. When the final must-stop
tid gets its group stop, we propagate the process state change.
Only the signal receiving the notification of the pending SIGSTOP
is marked with the SIGSTOP signal. All the rest, if they weren't
already stopped, are marked as stopped with signal 0.
* Fixes a few broken tests.
* Marks the Linux test I added earlier as expect-pass (no longer XFAIL).
Implements fix for http://llvm.org/bugs/show_bug.cgi?id=20908.
llvm-svn: 217647
This patch moves creates a thread abstraction that represents a
thread running inside the LLDB process. This is a replacement for
otherwise using lldb::thread_t, and provides a platform agnostic
interface to managing these threads.
Differential Revision: http://reviews.llvm.org/D5198
Reviewed by: Jim Ingham
llvm-svn: 217460
Yet another step toward ARM64 support. With this commit, lldb-gdbserver started on ARM64 target can be accessed by lldb running on desktop PC and it can process simple commands (like 'continue'). Still ARM64 support lacks NativeRegisterContextLinux_arm64.* code which waits to be implemented.
Based on similar files for Linux x86_64 and Darwin ARM64. Due to common code extraction from Darwin related files, lldb should be tested for any unexpected regression on Darwin ARM64 machines too.
See the following for more details:
http://reviews.llvm.org/D4580http://lists.cs.uiuc.edu/pipermail/lldb-commits/Week-of-Mon-20140825/012670.html
Change by Paul Osmialowski.
llvm-svn: 216737
This change:
* properly captures execs in NativeProcessLinux.
* clears out all non-main-thread thread metadata in NativeProcessLinux on exec.
* adds a DidExec() method to the NativeProcessProtocol delegate.
* clears out the auxv data cache when we exec (on Linux).
This is a small part of the llgs for local Linux debugging work going on here:
https://github.com/tfiala/lldb/tree/dev-llgs-local
I'm breaking it into small patches.
llvm-svn: 216670
I copied this originally based on what debugserver was doing. This appears to
be incorrect and unncessary for Linux. The LinuxSignals on the lldb side
don't look for these and therefore they get handled incorrectly.
Leaving the hook in place since I think darwin will continue to need to
translate those signal numbers.
llvm-svn: 216564
Also moves NativeRegisterContextLinux* files into the Linux directory.
These, like NativeProcessLinux, should only be built on Linux or a cross
compiler with proper headers.
llvm-svn: 212074
This change brings in lldb-gdbserver (llgs) specifically for Linux x86_64.
(More architectures coming soon).
Not every debugserver option is covered yet. Currently
the lldb-gdbserver command line can start unattached,
start attached to a pid (process-name attach not supported yet),
or accept lldb attaching and launching a process or connecting
by process id.
The history of this large change can be found here:
https://github.com/tfiala/lldb/tree/dev-tfiala-native-protocol-linux-x86_64
Until mid/late April, I was not sharing the work and continued
to rebase it off of head (developed via id tfiala@google.com). I switched over to
user todd.fiala@gmail.com in the middle, and once I went to github, I did
merges rather than rebasing so I could share with others.
llvm-svn: 212069
Pavel Labath