Also other option is that we don't have O_CREAT in flags and we get ENOENT from open().... but again can not check that today.
2014-03-26 21:52 GMT+01:00 Piotr Rak <[email protected]>: > No, closing before dup2 is not required, it should close fd and it should > be also atomic. I am wondering now if LLDB sets FileActions like it was > expecting that we use posix_spawn. > > I can not check it today... but will look at it tomorrow or during weekend. > > > 2014-03-26 21:33 GMT+01:00 Greg Clayton <[email protected]>: > > Looks like you might need to look at: >> >> ProcessMonitor::Launch(LaunchArgs *args) >> >> It is what does the fork + exec. >> >> It also looks like no matter what is sent to >> ProcessMonitor::Launch(LaunchArgs *args) for stdin, stdout, stderr, Linux >> _always_ launches using a pseudo terminal by doing: >> >> lldb_utility::PseudoTerminal terminal; >> if ((pid = terminal.Fork(err_str, err_len)) == -1) >> >> >> If you look at the "terminal.Fork()" code you will see that it actually >> sets stdin/out/err to the slave slide of the pseudo terminal, so there is >> no telling if the code in ProcessMonitor::Launch(): >> >> if (stdin_path != NULL && stdin_path[0]) >> if (!DupDescriptor(stdin_path, STDIN_FILENO, O_RDONLY)) >> exit(eDupStdinFailed); >> >> if (stdout_path != NULL && stdout_path[0]) >> if (!DupDescriptor(stdout_path, STDOUT_FILENO, O_WRONLY | >> O_CREAT)) >> exit(eDupStdoutFailed); >> >> if (stderr_path != NULL && stderr_path[0]) >> if (!DupDescriptor(stderr_path, STDERR_FILENO, O_WRONLY | >> O_CREAT)) >> exit(eDupStderrFailed); >> >> >> Will work? ProcessMonitor::DupDescriptor() does: >> >> >> bool >> ProcessMonitor::DupDescriptor(const char *path, int fd, int flags) >> { >> int target_fd = open(path, flags, 0666); >> >> if (target_fd == -1) >> return false; >> >> return (dup2(target_fd, fd) == -1) ? false : true; >> } >> >> I would assume you would need to call close() on stdin/out/err first? >> Again the PseudoTerminal::Fork() has always already setup stdin/out/err to >> the slave side and the DupDescriptor calls are probably failing. >> >> Greg >> >> >> On Mar 26, 2014, at 12:26 PM, Piotr Rak <[email protected]> wrote: >> >> > Hi, >> > >> > That got me curious and now I am bit confused how it works, and it >> should be really simple. >> > >> > I've checked Greg's example, it will just exit before main doing >> nothing. >> > I've no idea why yet, however I attached my perfect tracee: >> > >> > extern "C" void _start() >> > { >> > __asm__ volatile ( >> > "again:;" >> > "int $0x03;" >> > "jmp again;" >> > "movl $1,%eax;" >> > "xorl %ebx, %ebx;" >> > "int $0x80;" >> > ); >> > } >> > ls -al /proc/`pidof hello`/fd >> > >> > lrwx------ 1 prak prak 64 03-26 19:42 0 -> /dev/pts/19 >> > lrwx------ 1 prak prak 64 03-26 19:42 1 -> /dev/pts/19 >> > lrwx------ 1 prak prak 64 03-26 19:42 2 -> /dev/pts/19 >> > lrwx------ 1 prak prak 64 03-26 19:42 3 -> /dev/ptmx >> > lrwx------ 1 prak prak 64 03-26 19:42 5 -> /dev/pts/19 >> > >> > ls -al /proc/`pidof lldb`/fd >> > >> > lrwx------ 1 prak prak 64 03-26 19:43 0 -> /dev/pts/16 >> > lrwx------ 1 prak prak 64 03-26 19:43 1 -> /dev/pts/16 >> > lrwx------ 1 prak prak 64 03-26 19:43 2 -> /dev/pts/16 >> > lrwx------ 1 prak prak 64 03-26 19:43 3 -> /dev/ptmx >> > lrwx------ 1 prak prak 64 03-26 19:43 4 -> /dev/ptmx >> > lr-x------ 1 prak prak 64 03-26 19:43 5 -> pipe:[1301667] >> > l-wx------ 1 prak prak 64 03-26 19:43 6 -> pipe:[1301667] >> > lr-x------ 1 prak prak 64 03-26 19:43 7 -> pipe:[1299830] >> > l-wx------ 1 prak prak 64 03-26 19:43 8 -> pipe:[1299830] >> > >> > So it was spawned as usual using fork() by Linux/ProcessMonitor.cpp >> > And it was given slave pts, lldb however has no '/tmp/out.txt' file >> anywhere. >> > >> > Should this for this case?: >> > a) be passed opened to inferior before exec, or >> > b) lldb should read master pty and write to /tmp/out.txt >> > >> > I would guess that should be a: >> > >> > But probably then: >> > >> > SetSTDIOFileDescriptor(m_monitor->GetTerminalFD()); >> > >> > from ProcessPosix::DoLaunch() ProcessPosix.cpp:253 after creating >> process spoils the fun. >> > Also std{in,err,path)_path had to be empty here. >> > >> > Cheers, >> > /Piotr >> > >> > >> > 2014-03-26 19:08 GMT+01:00 Greg Clayton <[email protected]>: >> > Seems like we are having some problem re-directing to terminals and >> files that exist. I would try debugging through the launch process and see >> who is doing what with file re-direction. It works on MacOSX just fine, so >> this is probably a linux only issue. Linux does fork() + exec() so some >> code in there isn't doing the right things. >> > >> > % lldb >> > (lldb) settings set target.output-path /tmp/out.txt >> > (lldb) file /bin/ls >> > Current executable set to '/bin/ls' (x86_64). >> > (lldb) run /tmp/ >> > (lldb) Process 65933 launched: '/bin/ls' (x86_64) >> > Process 65933 exited with status = 0 (0x00000000) >> > (lldb) q >> > >> > % cat /tmp/out.txt >> > launch-B6FwKk >> > launch-OEyacj >> > launchd-142.5fRyOk >> > launchd-175.RBU3HO >> > launchd-193.Asuh1k >> > launchd-2701.dSHLJu >> > launchd-738.U2ACnW >> > out.txt >> > >> > % xcrun lldb >> > (lldb) settings set target.output-path /tmp/out.txt >> > (lldb) file /bin/ls >> > Current executable set to '/bin/ls' (x86_64). >> > (lldb) run / >> > (lldb) Process 65940 launched: '/bin/ls' (x86_64) >> > Process 65940 exited with status = 0 (0x00000000) >> > (lldb) q >> > lldb:/tmp % cat /tmp/out.txt >> > AppleInternal >> > Applications >> > Library >> > Network >> > SWE >> > System >> > Users >> > Volumes >> > bin >> > cores >> > dev >> > etc >> > home >> > mach_kernel >> > net >> > >> > >> > So this works on Darwin and needs to be fixed on Linux. >> > >> > Greg >> > >> > On Mar 25, 2014, at 7:15 AM, Eran Ifrah <[email protected]> wrote: >> > >> > > Hello Greg, >> > > Thanks for the input. It still does not work ( I rewrote my terminal >> code to look similar to lldb's PseudoTerminal, and it is still not working) >> > > >> > > To simplify things, I tried some basic things with the command line >> tool 'lldb': >> > > >> > > I created a file ~/.lldbinit with the following content: >> > > >> > > eran@eran-linux: ~/llvm/build/bin $ cat ~/.lldbinit >> > > settings set target.output-path /tmp/dbg.out >> > > eran@eran-linux: ~/llvm/build/bin $ >> > > >> > > I then ran lldb while having tail -f /tmp/dbg.out& in another >> terminal to see if the stdout is being redirected >> > > >> > > Now, this is the interesting part: >> > > In the first run when the file /tmp/dbg.out was empty - the >> redirection worked (tail showed the debuggee stdout) >> > > In the second run (and later) - nothing was written to the file >> > > >> > > However, if I truncate the file using the below command: >> > > >> > > $ > /tmp/dbg.out >> > > >> > > and run lldb again - I see the stdout again - but same as before only >> for the first time (i.e. as long as the file is empty the stdout was >> redirected) >> > > >> > > The next thing I tried was to use a terminal name for redirection: >> > > >> > > - Open a new terminal and type `tty` (in my case it gave /dev/pts/19 ) >> > > - Edit the ~/.lldbinit: settings set target.output-path /dev/pts/19 >> > > - Start lldb and verify that the setting is set properly by running: >> settings show target.output-path >> > > - Run the program under lldb - the output is not redirected (i.e. it >> is show in the same console where I ran lldb) >> > > >> > > Any ideas? >> > > >> > > P.S. >> > > Sorry if this looks like a voodoo, but this is what I am getting >> here... ;) >> > > >> > > Eran >> > > >> > > >> > > >> > > >> > > >> > > On Mon, Mar 24, 2014 at 6:46 PM, Greg Clayton <[email protected]> >> wrote: >> > > Check out the PseudoTerminal class in >> trunk/source/Utility/PseudoTerminal.cpp. >> > > >> > > See the function named PseudoTerminal::OpenFirstAvailableMaster(...). >> You must call posix_openpt, grantpt, and unlockpt. I am guessing that >> because you aren't calling grantpt and granting access to the slave you are >> failing to be able to use the slave in your child process. >> > > >> > > Greg Clayton >> > > >> > > On Mar 23, 2014, at 11:32 AM, Eran Ifrah <[email protected]> >> wrote: >> > > >> > > > Sure, thanks for the help so far >> > > > Eran >> > > > >> > > > >> > > > On Sun, Mar 23, 2014 at 8:31 PM, Piotr Rak <[email protected]> >> wrote: >> > > > I am sorry, but nothing obvious comes to me right now, probably >> you'll need to wait for Monday, when people more familiar with lldb will be >> able to help you debug this problem. >> > > > >> > > > >> > > > 2014-03-23 16:07 GMT+01:00 Eran Ifrah <[email protected]>: >> > > > >> > > > >> > > > >> > > > >> > > > On Sun, Mar 23, 2014 at 4:29 PM, Piotr Rak <[email protected]> >> wrote: >> > > > Sorry I misinformed you about posix_spawn - it is not true for >> Linux and FreeBSD at least, it will use ordinary fork. >> > > > >> > > > >> > > > 2014-03-23 15:23 GMT+01:00 Piotr Rak <[email protected]>: >> > > > >> > > > >> > > > Hi, >> > > > >> > > > 2014-03-23 14:04 GMT+01:00 Eran Ifrah <[email protected]>: >> > > > >> > > > Thanks for your pointer Piotr. Here is the code I am using to open >> a pseudo-terminal (there is the UI part, which I left out): >> > > > >> > > > char __name[128]; >> > > > memset(__name, 0, sizeof(__name)); >> > > > >> > > > int master(-1); >> > > > m_slave = -1; >> > > > if(openpty(&master, &m_slave, __name, NULL, NULL) != 0) >> > > > return wxT(""); >> > > > >> > > > // disable ECHO >> > > > struct termios termio; >> > > > tcgetattr(master, &termio); >> > > > termio.c_lflag = ICANON; >> > > > termio.c_oflag = ONOCR | ONLRET; >> > > > tcsetattr(master, TCSANOW, &termio); >> > > > >> > > > m_tty = wxString(__name, wxConvUTF8); >> > > > >> > > > At the end, m_tty contains a string name (e.g. /dev/pts/19 ). >> > > > Note that the above code works flawlessly when using it with gdb >> (i.e. if I pass this "/dev/pts/19" to gdb's switch -tty=/dev/pts/19 I will >> get all the inferior output/err/input to my internal terminal) >> > > > >> > > > However, doing the same with LLDB (using C++ API not the command >> line , i.e. passing "/dev/pts/19" as an argument to SBTarget::Launch(...)) >> I get nothing as output... >> > > > >> > > > Looks sane to me. >> > > > >> > > > Also, I am not sure I am following the idea behind replacing the >> "Launch" function with my own fork(), looking at the code of Launch() >> suggests that it does more than a simple fork... >> > > > >> > > > >> > > > That was my idea to debug issue if nothing else helps. >> > > > Or rather bisect on which side it really is, sorry if I did not >> make it clear... >> > > > So I was trying suggest replacing SBTarget::Launch with fork, >> write to child stdout/err, and see if that works alone.... >> > > > >> > > > SBTarget::Launch is usually actually posix_spawn right now, it uses >> posix_spawnattr_addopen to open descriptors for your specified paths, and >> should open it 3 times - given current implementation - even it is just one >> file. >> > > > >> > > > Have you inspected SBProcess and SBError returned by >> SBTarget::Launch? >> > > > >> > > > I checked IsValid() on both and its OK for both. I can actually run >> "next" Continue etc and seems to be working. Its just that I can't seem to >> redirect the stdout/err to my own console. >> > > > >> > > > >> > > > Do you see your inferior process is indeed launching, just not >> displaying anything? >> > > > Yes, ps -ef shows the debugee >> > > > >> > > > Do you have an option to check if those terminals are actually >> being opened (like examining /proc/<pid>/fd for linux)? >> > > > The terminal is opened. Like I mentioned in my previous email, >> using the _same_ code with gdb works >> > > > I also have a standalone terminal application which I wrote which >> is also using the same set of classes all of the are working for couple of >> years now without any problems >> > > > >> > > > I also tried this: >> > > > I typed in my konsole 'tty' and used that as the input for Launch - >> it also seems to have no effect >> > > > >> > > > >> > > > >> > > > Good luck, >> > > > /Piotr >> > > > >> > > > Any more hints? >> > > > Eran >> > > > >> > > > >> > > > >> > > > On Sat, Mar 22, 2014 at 9:36 PM, Piotr Rak <[email protected]> >> wrote: >> > > > Hi, >> > > > >> > > > It should. >> > > > Have you opened master pseudoterminal like?: >> > > > >> > > > int fd = posix_openpt(flags); // open("/dev/ptmx") might work here >> too but less portable; >> > > > grantpt(fd); >> > > > unlockpt(fd); >> > > > >> > > > Depending on target you might need some bizarre ioctls here, but >> assuming you are using Linux/FreeBSD/MacOSX >> > > > you should be fine. >> > > > >> > > > If you had already master pseudo-terminal file descriptor you can >> skip steps above. >> > > > >> > > > You can use ptsname for master file descriptor it will return you >> name of slave pseudo-terminal for your master. >> > > > Later you can pass name returned by ptsname(fd) as Launch arguments. >> > > > >> > > > If above won't work you can try replacing Launch() call with >> ordinary fork, and in child process: >> > > > >> > > > slavefd = open(slavename, O_RDWR); >> > > > >> > > > dup2(0, slavefd); >> > > > dup2(1, slavefd); >> > > > dup2(2, slavefd); >> > > > >> > > > And see if that works alone for you... >> > > > >> > > > Good luck, >> > > > /Piotr >> > > > >> > > > >> > > > 2014-03-22 19:29 GMT+01:00 Eran Ifrah <[email protected]>: >> > > > Hello, >> > > > >> > > > I am trying to use the C++ API with good success so far. >> > > > I am now at a point where I want to redirect stdin/out/err of the >> inferior to my application (my application creates a separate pseudo >> terminal window) >> > > > >> > > > Looking at the SBTarget::Launch, I thought that simply passing >> "/dev/pts/<some-number>" as the 3rd, 4th and 5th argument will do the trick >> .. well, it did not. >> > > > I am missing something basic here, can anyone shed some light >> please? or give an example (better) of how to achieve this? >> > > > >> > > > Thanks! >> > > > >> > > > -- >> > > > Eran Ifrah >> > > > Author of codelite, a cross platform open source C/C++ IDE: >> http://www.codelite.org >> > > > wxCrafter, a wxWidgets RAD: http://wxcrafter.codelite.org >> > > > >> > > > _______________________________________________ >> > > > lldb-dev mailing list >> > > > [email protected] >> > > > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev >> > > > >> > > > >> > > > >> > > > >> > > > >> > > > -- >> > > > Eran Ifrah >> > > > Author of codelite, a cross platform open source C/C++ IDE: >> http://www.codelite.org >> > > > wxCrafter, a wxWidgets RAD: http://wxcrafter.codelite.org >> > > > >> > > > >> > > > >> > > > >> > > > >> > > > -- >> > > > Eran Ifrah >> > > > Author of codelite, a cross platform open source C/C++ IDE: >> http://www.codelite.org >> > > > wxCrafter, a wxWidgets RAD: http://wxcrafter.codelite.org >> > > > >> > > > >> > > > >> > > > >> > > > -- >> > > > Eran Ifrah >> > > > Author of codelite, a cross platform open source C/C++ IDE: >> http://www.codelite.org >> > > > wxCrafter, a wxWidgets RAD: http://wxcrafter.codelite.org >> > > > _______________________________________________ >> > > > lldb-dev mailing list >> > > > [email protected] >> > > > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev >> > > >> > > >> > > >> > > >> > > -- >> > > Eran Ifrah >> > > Author of codelite, a cross platform open source C/C++ IDE: >> http://www.codelite.org >> > > wxCrafter, a wxWidgets RAD: http://wxcrafter.codelite.org >> > >> > >> >> >
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