Summary:
The lambda was always calling SetState(eStateStopped) with small variations, so I have inlined
the code. Given that we don't have the TSC anymore, I believe we don't need to be so generic.
The only major change here is the way we choose a stop reason thread when we're interrupting a
program on client request. Previously, we were setting a null stop reason for all threads and
then fixing up the reason for one victim thread in the lambda. Now, I make sure the stop reason
is set for the victim thread correctly in the first place.
I also take the opportunity to rename CallAfter* functions into something more appropriate.
Test Plan: All tests continue to pass.
Reviewers: chaoren, vharron
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9321
llvm-svn: 236595
Summary:
Since all TSC operations are now executed synchronously, TSC has become a little more than a
messenger between different parts of NativeProcessLinux. Therefore, the reason for its existance
has disappeared.
This commit moves the contents of the TSC into the NPL class. This will enable us to remove all
the boilerplate code in NPL (as it stands now, this is most of the class), which I plan to do in
subsequent commits.
Unfortunately, this also means we will lose the unit tests for the TSC. However, since the size
of the TSC has diminished, the unit tests were not testing much at this point anyway, so it's not
a big loss.
No functional change.
Test Plan: All tests continue to pass.
Reviewers: vharron, chaoren
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9296
llvm-svn: 236587
Summary:
This is a cleanup patch for thread state coordinator. After making processing of all events
synchronous, there is no need to have a a separate class for each event. I have moved back
processing of all events back into the TSC class. No functional change.
Test Plan: All tests continue to pass.
Reviewers: chaoren, vharron
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9254
llvm-svn: 236576
Summary:
This change removes the thread state coordinator thread by making all the operations it was
performing synchronous. In order to prevent deadlock, NativeProcessLinux must now always call
m_monitor->DoOperation with the m_threads_mutex released. This is needed because HandleWait
callbacks lock the mutex (which means the monitor thread will block waiting on whoever holds the
lock). If the other thread now requests a monitor operation, it will wait for the monitor thread
do process it, creating a deadlock.
To preserve this invariant I have introduced two new Monitor commands: "begin operation block"
and "end operation block". They begin command blocks the monitor from processing waitpid
events until the corresponding end command, thereby assuring the monitor does not attempt to
acquire the mutex.
Test Plan: Run the test suite locally, verify no tests fail.
Reviewers: vharron, chaoren
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9227
llvm-svn: 236501
Summary:
NativeProcessProtocol uses ReadMemory internally for setting/checking
breakpoints but also for generic memory reads (Handle_m), this change adds a
ReadMemoryWithoutTrap for that purpose. Also fixes a bunch of misuses of addr_t
as size/length.
Test Plan: `disassemble` no longer shows the trap code.
Reviewers: jingham, vharron, clayborg
Reviewed By: clayborg
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9330
llvm-svn: 236132
This code is also an import from MacOSx implementation as SysV abi is
similar to what has been implemented for MacOS but may require a few tweaks.
http://reviews.llvm.org/D8538
llvm-svn: 236098
Summary:
Without the synchronisation between the two thread creation events the following case could
happen:
- threads A and B are running. A hits a breakpoint. We note that we want to stop B.
- before we could stop it, B creates a new thread C, we get the stop notification for B, but we
don't record C's existence yet.
- we resume B
- before we get the C notification, B stops again (e.g. hits a breakpoint, gets our SIGSTOP,
etc.)
- we see all known threads have stopped, and we notify LLDB
- C notification comes, we note it's existence and resume it
=> we have an inconsistent state (LLDB thinks we've stopped, but C is running)
I resolve this by doing a blocking wait for for the C notification when we get the creation
notification on the parent (B) thread. This way the two events are synchronised, but we don't
need to introduce the intermediate "launching" state which would complicate handling of thread
states as all code would need to be aware of the third possible state.
Test Plan:
This is an obscure corner case, which I had not observed in practise, so I have no
test for it. I have tested that this commit does not regress in existing tests though.
Reviewers: chaoren, vharron
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9217
llvm-svn: 235969
Summary:
Currently, launching lldb-gdbserver from platform on Android requires root for
mkfifo() and an explicit TMPDIR variable. This should remove both requirements.
Test Plan: Successfully launched lldb-gdbserver on a non-rooted Android device.
Reviewers: tberghammer, vharron, clayborg
Reviewed By: clayborg
Subscribers: tberghammer, lldb-commits
Differential Revision: http://reviews.llvm.org/D9307
llvm-svn: 235940
The previous read callback always read the value of the register what
caused problems when the emulator wrote some value into a register and
then expected to read the same value back. This CL add a register value
cache into the callbacks to return the correct value after a register
write also.
Test Plan: Stepping over BL/BLX instruction works on android-arm if the instruction set isn't change (other, unrelated patch will come for the case when we move to an other instruction set)
Reviewers: omjavaid, sas, clayborg
Reviewed By: clayborg
Subscribers: labath, tberghammer, rengolin, aemerson, lldb-commits
Differential Revision: http://reviews.llvm.org/D9187
From: Tamas Berghammer <tberghammer@google.com>
llvm-svn: 235852
Summary:
LLGS leaks pipes (when launched by lldb), sockets (when launched by platform),
and/or log file to the inferior. This should prevent all possible leaks.
Reviewers: vharron, clayborg
Reviewed By: clayborg
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9211
llvm-svn: 235615
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
Patch by Jaydeep Patil
Added MIPS32 and MIPS64 core revisions. This would be followed by register context and emulate-instruction for MIPS32.
DYLDRendezvous.cpp:
On Linux link map struct does not contain extra load offset field.
Reviewers: clayborg
Subscribers: bhushan, mohit.bhakkad, sagar, lldb-commits.
Differential Revision: http://reviews.llvm.org/D9190
llvm-svn: 235574
On linux-arm we use software single stepping where setting the new
breakpoint is only possible while the process is in stopped state.
This CL moves the setup code for single stepping form the SigneStep
operation into the Resum method to avoid an error when the process
already started when we want to step one of the thread.
Differential revision: http://reviews.llvm.org/D9108
llvm-svn: 235494
Summary:
This commit moves the functionality of the operation thread into the new monitor thread. This is
required to avoid a kernel race between the two threads and I believe it actually makes the code
cleaner.
Test Plan: Ran the test suite a couple of times, no regressions.
Reviewers: ovyalov, tberghammer, vharron
Subscribers: tberghammer, lldb-commits
Differential Revision: http://reviews.llvm.org/D9080
llvm-svn: 235304
The arm instruction emulation handles only some of the opcode (including
all of them modifying the PC). For the rest of the instructions we can
advance the PC by the size of the instruction as they don't modify the
PC on any other way.
Differential revision: http://reviews.llvm.org/D9076
llvm-svn: 235292
Summary:
This is the first phase of the merging of Monitor and Operation threads in NativeProcessLinux
(which is necessary since the two threads race inside Linux kernel). Here, I reimplement the
Monitor thread do use non-blocking waitpid calls, which enables later addition of code from the
operation thread.
Test Plan: Ran the test suite a couple of times, no regressions detected.
Reviewers: vharron, ovyalov, tberghammer
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9048
llvm-svn: 235193
the changes in r233255/r233258. Normally if lldb attaches to
a running process, when we call Process::Destroy, we want to detach
from the process. If lldb launched the process itself, ::Destroy
should kill it.
However, if we attach to a process and the driver calls SBProcess::Kill()
(which calls Destroy), we need to kill it even if we didn't launch it
originally.
The force_kill param allows for the SBProcess::Kill method to force the
behavior of Destroy.
<rdar://problem/20424439>
llvm-svn: 235158
Also add "#if defined( LIBXML2_DEFINED )" around code that already used libxml2 in SymbolVendorMacOSX.cpp.
Cleaned up some warnings in ProcessGDBRemote.cpp.
llvm-svn: 235144
Typically, LLGS only sends stdout/stderr notifications when the inferior
process is running.
Because LLGS reads stdout from the process in a separate thread, sometimes
these stdout notifications can be received after the server has sent a thread
stop message. The host isn't expecting stdout to be generated by the target
after a stop message and these messages interfere with the host's request/
response paradigm.
Differential Revision: http://reviews.llvm.org/D9024
llvm-svn: 234995
Linux arm don't support hardware stepping (neither mismatch
breakpoints). This patch implement signle stepping with doing a software
emulation of the next instruction and then setting a temporary
breakpoint at the address where the thread will stop next.
Differential revision: http://reviews.llvm.org/D8976
llvm-svn: 234987
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
The OperatingSystem plug-ins allow code to detect threads in memory and then say "memory thread 0x11111" is backed by the actual thread 1.
You can then single step these virtual threads. A problem arose when thread specific breakpoints were used during thread plans where we would say "set a breakpoint on thread 0x11111" and we would hit the breakpoint on the real thread 1 and the thread IDs wouldn't match and we would get rid of the "stopped at breakpoint" stop info due to this mismatch. Code was added to ensure these events get forwarded and thus allow single stepping a memory thread to work correctly.
Added a test case for this as well.
<rdar://problem/19211770>
llvm-svn: 234364
The FreeBSD debug register access is a little usual, but in any case
different from Linux. As it stands it's not possible to share an
implementation of DR_OFFSET, so revert that part of r233837 and provide
a separate FreeBSD and Linux implementation.
We'll still want a better fix, but this should restore basic
functionality (and the buildbot).
llvm-svn: 234048
