Summary:
Memory reads using the ptrace API need to be executed on a designated thread
and in 4-byte increments. The process_vm_read syscall has no such requirements
and it is about 50 times faster. This patch makes lldb-server use the faster
API if the target kernel supports it. Kernel support for this feature is
determined at runtime. Using process_vm_writev in the same manner is more
complicated since this syscall (unlike ptrace) respects page protection settings
and so it cannot be used to set a breakpoint, since code pages are typically
read-only. However, memory writes are not currently a performance bottleneck as
they happen much more rarely.
Test Plan: all tests continue to pass
Reviewers: ovyalov, vharron
Subscribers: tberghammer, lldb-commits
Differential Revision: http://reviews.llvm.org/D10488
llvm-svn: 239924
In order to support asynchronous notifications for non-stop mode this patch adds a packet read thread. This is done by implementing AppendBytesToCache() from the communications class, which continually reads packets into a packet queue. To initialize this thread StartReadThread() must be called by the client, so since llgs and platform tools use the GBDRemoteCommunicatos code they must also call this function as well as ProcessGDBRemote.
When the read thread detects an async notify packet it broadcasts this event, where the matching listener will be added in the next non-stop patch.
Packets are now accessed by calling ReadPacket() which pops a packet from the queue, instead of using WaitForPacketWithTimeoutMicroSecondsNoLock()
Reviewers: vharron, clayborg
Subscribers: lldb-commits, labath, ted, domipheus, deepak2427
Differential Revision: http://reviews.llvm.org/D10085
llvm-svn: 239824
Summary:
This should solve the issue of sending denormalized paths over gdb-remote
if we stick to GetPath(false) in GDBRemoteCommunicationClient, and let the
server handle any denormalization.
Reviewers: ovyalov, zturner, vharron, clayborg
Reviewed By: clayborg
Subscribers: tberghammer, emaste, lldb-commits
Differential Revision: http://reviews.llvm.org/D9728
llvm-svn: 238604
Since interaction with the python interpreter is moving towards
being more isolated, we won't be able to include this header from
normal files anymore, all includes of it should be localized to
the python library which will live under source/bindings/API/Python
after a future patch.
None of the files that were including this header actually depended
on it anyway, so it was just a dead include in every single instance.
llvm-svn: 238581
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
qEcho:%s
where '%s' is any valid string. The response to this packet is the exact packet itself with no changes, just reply with what you received!
This will help us to recover from packets timing out much more gracefully. Currently if a packet times out, LLDB quickly will hose up the debug session. For example, if we send a "abc" packet and we expect "ABC" back in response, but the "abc" command takes longer than the current timeout value this will happen:
--> "abc"
<-- <<<error: timeout>>>
Now we want to send "def" and get "DEF" back:
--> "def"
<-- "ABC"
We got the wrong response for the "def" packet because we didn't sync up with the server to clear any current responses from previously issues commands.
The fix is to modify GDBRemoteCommunication::WaitForPacketWithTimeoutMicroSecondsNoLock() so that when it gets a timeout, it syncs itself up with the client by sending a "qEcho:%u" where %u is an increasing integer, one for each time we timeout. We then wait for 3 timeout periods to sync back up. So the above "abc" session would look like:
--> "abc"
<-- <<<error: timeout>>> 1 second
--> "qEcho:1"
<-- <<<error: timeout>>> 1 second
<-- <<<error: timeout>>> 1 second
<-- "abc"
<-- "qEcho:1"
The first timeout is from trying to get the response, then we know we timed out and we send the "qEcho:1" packet and wait for 3 timeout periods to get back in sync knowing that we might actually get the response for the "abc" packet in the mean time...
In this case we would actually succeed in getting the response for "abc". But lets say the remote GDB server is deadlocked and will never response, it would look like:
--> "abc"
<-- <<<error: timeout>>> 1 second
--> "qEcho:1"
<-- <<<error: timeout>>> 1 second
<-- <<<error: timeout>>> 1 second
<-- <<<error: timeout>>> 1 second
We then disconnect and say we lost connection.
We might also have a bad GDB server that just dropped the "abc" packet on the floor. We can still recover in this case and it would look like:
--> "abc"
<-- <<<error: timeout>>> 1 second
--> "qEcho:1"
<-- "qEcho:1"
Then we know our remote GDB server is still alive and well, and it just dropped the "abc" response on the floor and we can continue to debug.
<rdar://problem/21082939>
llvm-svn: 238530
Summary:
Previously, we wait()ed for events from the inferiors process group. This is resulted in a
failure if the inferior changed its process group in the middle of execution. To avoid this, I
pass -1 to the wait() call. The flag __WNOTHREAD makes sure we don't actually wait for events
from any process, but only the processes(threads) which are our children (or traced by us). Since
this happens on the monitor thread, which is dedicated to monitoring a single inferior, we will
be getting events only from this inferior.
Test Plan: All tests pass on linux. I have added a test to check the new functionality.
Reviewers: chaoren, ovyalov
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D10061
llvm-svn: 238405
In ProcessGDBRemote we currently have a single packet, m_last_stop_packet, used to set the thread stop info.
However in non-stop mode we can receive several stop reply packets in a sequence for different threads. As a result we need to use a container to hold them before they are processed.
This patch also changes the return type of CheckPacket() so we can detect async notification packets.
Reviewers: clayborg
Subscribers: labath, ted, deepak2427, lldb-commits
Differential Revision: http://reviews.llvm.org/D9853
llvm-svn: 238323
This change also get rid of an unused Debugger instance in
GDBRemoteCommunicationServerLLGS and the command interpreter from
lldb-platform what was used only for enabling logging.
Differential revision: http://reviews.llvm.org/D9876
llvm-svn: 238319
We know have on API we should use for all XML within LLDB in XML.h. This API will be easy back the XML parsing by different libraries in case libxml2 doesn't work on all platforms. It also allows the only place for #ifdef ...XML... to be in XML.h and XML.cpp. The API is designed so it will still compile with or without XML support and there is a static function "bool XMLDocument::XMLEnabled()" that can be called to see if XML is currently supported. All APIs will return errors, false, or nothing when XML isn't enabled.
Converted all locations that used XML over to using the host XML implementation.
Added target.xml support to debugserver. Extended the XML register format to work for LLDB by including extra attributes and elements where needed. This allows the target.xml to replace the qRegisterInfo packets and allows us to fetch all register info in a single packet.
<rdar://problem/21090173>
llvm-svn: 238224
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
The main issue was the Communication::Disconnect() was calling its Connection::Disconnect() but this wouldn't release the pipes that the ConnectionFileDescriptor was using. We also have someone that is holding a strong reference to the Process so that when you re-run, target replaces its m_process_sp, but it doesn't get destructed because someone has a strong reference to it. I need to track that down. But, even if we have a strong reference to the a process that is outstanding, we need to call Process::Finalize() to have it release as much of its resources as possible to avoid memory bloat.
Removed the ProcessGDBRemote::SetExitStatus() override and replaced it with ProcessGDBRemote::DidExit().
Now we aren't leaking file descriptors and the stand alone test suite should run much better.
llvm-svn: 238089
Summary: This enables correct handling of real time signals by lldb.
Test Plan: Added a test that verifies handling of SIGRTMIN
Reviewers: tberghammer, ovyalov
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9911
llvm-svn: 238009
Summary:
Previously, NPL tried to reinject SIGSTOP into the inferior in an attempt to get the process to
start in the group-stop state. This was:
a) wrong (reinjection should be controlled by "process handle" lldb setting)
b) racy (it should use Resume for transparent resuming instead of RequestResume)
c) broken (llgs crashed on inferior SIGSTOP)
With this change, SIGSTOP is handled just like any other signal delivered to the inferior: we
stop all threads and report signal reception to lldb. SIGSTOP reinjection does not behave the
same way as it would outside the debugger, but simulating this is a hard problem and is not
normally necessary.
Test Plan: I have added a test which verifies we get SIGSTOP reports and we do not crash.
Reviewers: ovyalov, chaoren
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9852
llvm-svn: 237880
Summary:
The test in TestPlatformCommand which runs "platform process list" has
been timing out for Android when running running dosep.py with
LLDB_TEST_THREADS=8. This patch increases the packet timeout to a large
value of 1min to accommodate the long time required for a response for
the qfProcessInfo packet on Android.
Test Plan: LLDB_TEST_THREADS=8 ./dosep.py on Android.
Reviewers: chaoren
Reviewed By: chaoren
Subscribers: tberghammer, lldb-commits
Differential Revision: http://reviews.llvm.org/D9866
llvm-svn: 237752
Summary:
There was an issue in NPL, where we attempted removal of temporary breakpoints (used to implement
software single stepping), while some threads of the process were running. This is a problem
since we currently always use the main thread's ID in the removal ptrace call. Therefore, if the
main thread was still running, the ptrace call would fail, and the software breakpoint would
remain, causing all kinds of problems. This change removes the breakpoints after all threads have
stopped. This fixes TestExitDuringStep on Android arm and can also potentially help in other
situations, as previously the breakpoint would not get removed if the thread stopped for another
reason.
Test Plan: TestExitDuringStep passes, other tests remain unchanged.
Reviewers: tberghammer
Subscribers: tberghammer, aemerson, lldb-commits
Differential Revision: http://reviews.llvm.org/D9792
llvm-svn: 237448
Summary:
This is the same issue as we had in D9145 for thread creation. Going through the full
ThreadDidStop/RequestResume cycle can cause a deferred notification to fire, which is not correct
when we are ignoring an event and resuming the thread. In this case it doesn't matter much since
the thread will die after that anyway, but for correctness, we should do the same thing here.
Also treating the SIGTRAP case the same way.
Test Plan: Tests continue to pass.
Reviewers: chaoren, ovyalov
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9696
llvm-svn: 237445
r237411 exposed the following issue: ProcessGDBRemote used the description field in the
stop-reply to set the description of the StopInfo. In the case of watchpoints, the packet
description contains the raw address that got hit, which is not exactly the information we want
to display to the user as the stop info. Therefore, I have changed the code to use the packet
description only if the StopInfo does not already have a description. This makes the behavior
equivalent to the pre-r237411 behavior as then the SetDecription call got ignored for
watchpoints.
llvm-svn: 237436
There were two versions of DoAttachToprocessWithId. One that takes
a pid_t, and the other which takes a pid_t and a ProcessAttachInfo.
There were no callers of the former version, and all of the
implementations of this version were simply forwarding calls to
one version or the other.
llvm-svn: 237281
Summary:
This patch is the beginnings of support for Non-stop mode in the remote protocol. Letting a user examine stopped threads, while other threads execute freely.
Non-stop mode is enabled using the setting target.non-stop-mode, which sends a QNonStop packet when establishing the remote connection.
Changes are also made to treat the '?' stop reply packet differently in non-stop mode, according to spec https://sourceware.org/gdb/current/onlinedocs/gdb/Remote-Non_002dStop.html#Remote-Non_002dStop.
A setting for querying the remote for default thread on setup is also included.
Handling of '%' async notification packets will be added next.
Reviewers: clayborg
Subscribers: lldb-commits, ADodds, ted, deepak2427
Differential Revision: http://reviews.llvm.org/D9656
llvm-svn: 237239
Removed some unused variables, added some consts, changed some casts
to const_cast. I don't think any of these changes are very
controversial.
Differential Revision: http://reviews.llvm.org/D9674
llvm-svn: 237218
Summary:
GetCurrentDirectory() returns the number of characters copied; 0 is a failure, not a success.
Add implementation for chdir().
Reviewers: zturner
Reviewed By: zturner
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9300
llvm-svn: 237162
The defult implementation falls back to GetRegisterCount what
includes the debug registers also what shouldn't be displayed to
the user.
llvm-svn: 237111
Summary:
NPL::Resume attempted to handle eStateStopped as a resume action. However:
- GDBRemoteCommunicationServerLLGS (the only user of NPL) never sets this action
- it could set this action in response to a vCont:t packet, but LLDB never produces this packet
- gdb-remote protocol documentation says vCont:t packet is used only in non-stop mode, but LLDB
does not support non-stop mode
- even if LLDB supported non-stop mode, this implementation of eStateStopped does something
different from what the spec says it should (according to spec, it should stop the specified
thread, but this seems to want to stop all threads).
Given the facts above, I believe we should remove this unused and untested code, as it probably
doesn't even work and removing it makes the rest of the code noticably simpler.
Reviewers: ovyalov, chaoren
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9657
llvm-svn: 237103
Summary:
Since the former-TSC events are now processed synchronously, there is no need for to protect them
with a separate mutex - all the actions are now guarded by the big m_threads_mutex.
With the mutex gone, the following functions, no longer have any purpose and were removed:
NotifyThreadCreate: replaced by direct calls to ThreadWasCreated
NotifyThreadStop: replaced by direct calls to ThreadDidStop
NotifyThreadDeath: folded into StopTrackingThread
ResetForExec: inlined as it consisted of a single line of code
RequestThreadResume(AsNeeded): replaced by direct calls to ResumeThread
StopThreads: removed, as it was never called
Test Plan: tests continue to pass
Reviewers: ovyalov, chaoren
Subscribers: lldb-commits
Differential Revision: http://reviews.llvm.org/D9603
llvm-svn: 237101
