What I now believe is happening is lldb-server is exiting for some reason and 
then the process just runs and still shows the output in LLDB because we hooked 
up the STDIO. I see lldb-server exits with an exit code of 0, but no command 
had been sent to terminate it. I will track that down.

Also, log_channels in lldb-gdbserver.cpp is using a llvm::StringRef incorrectly:

    case 'c': // Log Channels
      if (optarg && optarg[0])
        log_channels = StringRef(optarg);
      break;

Bad! This is exactly when we shouldn't be using llvm::StringRef. optarg is a 
static variable and can change if there are any arguments after "-c <args>".

Greg

> On Apr 12, 2017, at 10:05 AM, Tamas Berghammer <tbergham...@google.com> wrote:
> 
> If the process is restarted by lldb-server then "posix ptrace" should have 
> some indication about it. Also "posix process" and "posix thread" can be 
> useful to understand the bigger picture (all of them in lldb-server).
> 
> Note: You can enable them by setting LLDB_SERVER_LOG_CHANNELS and 
> LLDB_DEBUGSERVER_LOG_FILE environment variables before starting lldb.
> 
> On Wed, Apr 12, 2017 at 5:11 PM Greg Clayton <clayb...@gmail.com 
> <mailto:clayb...@gmail.com>> wrote:
> What is actually happening is we are stopped and handling the EntryBreakpoint 
> and are in the process of trying to load all shared libraries, and then a 
> signal (I am guessing) comes into the lldb-server and causes the target to 
> resume. Not sure if that is due to the signal passing packet:
> 
> $QPassSignals:0e;1b;20;21;22;23;24;25;26;27;28;29;2a;2b;2c;2d;2e;2f;30;31;32;33;34;35;36;37;38;39;3a;3b;3c;3d;3e;3f;40#69
> 
> that gets sent these days. I will try removing this and seeing if it fixes 
> anything.
> 
> Is there any logging I can enabled in lldb-server to catch the resume? I 
> haven't looked at the code but I finally proved what was happening last night 
> (target resumes while we are stopped at a breakpoint somehow). The program 
> runs and exits and when the shared libraries are finally done loading, there 
> is no connection to speak to.
> 
> Greg
> 
>> On Apr 11, 2017, at 8:26 AM, Pavel Labath <lab...@google.com 
>> <mailto:lab...@google.com>> wrote:
>> 
>> 
>> 
>> On 11 April 2017 at 15:56, Greg Clayton <clayb...@gmail.com 
>> <mailto:clayb...@gmail.com>> wrote:
>> 
>>> On Apr 11, 2017, at 5:33 AM, Pavel Labath <lab...@google.com 
>>> <mailto:lab...@google.com>> wrote:
>>> 
>>> Are you sure this is not just an artifact of stdio buffering? I tried the 
>>> same experiment, but I placed a real log statement, and I could see that 
>>> all the LoadModuleAtAddress calls happen between the $T and $c packets in 
>>> the gdb-remote packet sequence. 
>>> 
>>> The module loading should be synchronous, so I think the problem lies 
>>> elsewhere.
>>> 
>>> What is the nature of the breakpoint that is not getting hit? Can you 
>>> provide a repro case? The only bug like this that I am aware of is that we 
>>> fail to hit breakpoints in global constructors in shared libraries, but 
>>> that hasn't worked even in 3.8..
>> 
>> I unfortunately can't attach a repro case. I will be able to track this 
>> down, just need some pointers. I did notice that I wasn't able to hit 
>> breakpoints in global constructors though... Do we know why? On Mac, we get 
>> notified of shared libraries as they load so we never miss anything. Why are 
>> we not able to get the same thing with linux?
>> 
>> 
>> It looks like we are intercepting the library load too late, but I haven't 
>> investigated yet how to fix it. It's definitely possible (this works fine in 
>> gdb), but I don't know how, as the dynamic linker is still a big unknown to 
>> me. FWIW, I think I'll be messing with the dynamic loader plugin soon(ish), 
>> so I'll try to fix this then.
>> 
>> pl
> 

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