Repository navigation
rr record is stuck and doesnt proceed #2627
Description
Activity
What is the tracee program doing when things get stuck?
Thanks kyle for the response. I think the tracee program isdoing mem-write to a pci-e mapped device. Not sure of exact function yet. I am looking into it though. problem is rr has already debugging with ptrace, so I am not able to attach the gdb to my process.
If you have rr in gdb you can
call emergency_debug(<the correct Task* here>)which will stop tracee execution and switch rr to a gdbserver mode (which you can then connect to with a different gdb and inspect the tracee state).Running rr record up to the hang with
RR_LOG=all:debugmight be interesting too.- added a commit that references this issue
on Jul 22, 2021 @rajeshgangam Is there any chance that you can query
uname -afor this machine or remember what distro that was?
my rr record is stuck waiting for a response. Not sure what is the issue. Here is backtrace when it is stuck.
Attaching to process 20306
[New LWP 20313]
[New LWP 20317]
[New LWP 20318]
[New LWP 20319]
[New LWP 20320]
[New LWP 20321]
[New LWP 20322]
[New LWP 20323]
[New LWP 20324]
[New LWP 20325]
[New LWP 20327]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007f5442f34f7b in __waitpid (pid=30031, stat_loc=0x7ffdb221951c, options=1073741824) at ../sysdeps/unix/sysv/linux/waitpid.c:29
29 ../sysdeps/unix/sysv/linux/waitpid.c: No such file or directory.
(gdb) bt
#0 0x00007f5442f34f7b in __waitpid (pid=30031, stat_loc=0x7ffdb221951c, options=1073741824) at ../sysdeps/unix/sysv/linux/waitpid.c:29
#1 0x00000000005d31ee in rr::Task::wait(double) ()
#2 0x00000000005b436f in rr::Scheduler::reschedule(rr::Switchable) ()
#3 0x00000000005400ec in rr::RecordSession::record_step() ()
#4 0x0000000000535e21 in rr::RecordCommand::run(std::vector<std::__cxx11::basic_string<char, std::char_traits, std::allocator >, std::allocator<std::__cxx11::basic_string<char, std::char_traits, std::allocator > > >&) ()
#5 0x00000000004ac743 in main ()
(gdb) n
31 in ../sysdeps/unix/sysv/linux/waitpid.c
(gdb) c
Continuing.