[lldb-dev] Question (bug?) about thread tids when lldb loads a core dump.
Greg Clayton
gclayton at apple.com
Thu Jul 30 10:39:35 PDT 2015
I know why this is happening: the ELF core file was copied from the mach-o core file and in mach-o core files we have load commands in the file that describe each thread's registers, but there is no thread ID in the load command that says "this is thread 0x7f01fc42a700".
If ELF core files actually do have the thread IDs in the core files, then this is easy to fix and is an LLDB bug.
Greg
> On Jul 29, 2015, at 6:41 PM, Mike McLaughlin <mikem at microsoft.com> wrote:
>
> When I load a core dump with lldb 3.6, the tids displayed in “thread list” and more importantly returned by lldb::SBThread::GetThreadID() (used in a lldb plugin I wrote) doesn’t match the tids from the live session the core was generatedfrom. gdb displays the correct tids on the same core dump (see below). My plugin depends on the above api returning the tid during the live session.
>
>
>
> Can anybody help?
>
>
>
> lldb-3.6
>
> (lldb) target create --core /tmp/core-corerun-6-1000-1000-20870-1438119958 /tmp/corerun
>
> Core file '/tmp/core-corerun-6-1000-1000-20870-1438119958' (x86_64) was loaded.
>
> Process 0 stopped
>
> * thread #1: tid = 0x0000, 0x00007f01fe64d267 libc.so.6`gsignal + 55, name = 'corerun', stop reason = signal SIGABRT
>
> frame #0: 0x00007f01fe64d267 libc.so.6`gsignal + 55
>
> -> 0x7f01fe64d267: addb %al, (%rax)
>
> 0x7f01fe64d269: addb %al, (%rax)
>
> 0x7f01fe64d26b: addb %al, (%rax)
>
> 0x7f01fe64d26d: addb %al, (%rax)
>
> thread #2: tid = 0x0001, 0x00007f01fe7138dd libc.so.6`__poll + 45, stop reason = signal SIGABRT
>
> frame #0: 0x00007f01fe7138dd libc.so.6`__poll + 45
>
> -> 0x7f01fe7138dd: addb %al, (%rax)
>
> 0x7f01fe7138df: addb %al, (%rax)
>
> 0x7f01fe7138e1: addb %al, (%rax)
>
> 0x7f01fe7138e3: addb %al, (%rax)
>
> thread #3: tid = 0x0002, 0x00007f01fd27dda0 libpthread.so.0`__pthread_cond_wait + 192, stop reason = signal SIGABRT
>
> frame #0: 0x00007f01fd27dda0 libpthread.so.0`__pthread_cond_wait + 192
>
> -> 0x7f01fd27dda0: addb %al, (%rax)
>
> 0x7f01fd27dda2: addb %al, (%rax)
>
> 0x7f01fd27dda4: addb %al, (%rax)
>
> 0x7f01fd27dda6: addb %al, (%rax)
>
> thread #4: tid = 0x0003, 0x00007f01fd27e149 libpthread.so.0`__pthread_cond_timedwait + 297, stop reason = signal SIGABRT
>
> frame #0: 0x00007f01fd27e149 libpthread.so.0`__pthread_cond_timedwait + 297
>
> -> 0x7f01fd27e149: addb %al, (%rax)
>
> 0x7f01fd27e14b: addb %al, (%rax)
>
> 0x7f01fd27e14d: addb %al, (%rax)
>
> 0x7f01fd27e14f: addb %al, (%rax)
>
> thread #5: tid = 0x0004, 0x00007f01fe70f28d libc.so.6`__open64 + 45, stop reason = signal SIGABRT
>
> frame #0: 0x00007f01fe70f28d libc.so.6`__open64 + 45
>
> -> 0x7f01fe70f28d: addb %al, (%rax)
>
> 0x7f01fe70f28f: addb %al, (%rax)
>
> 0x7f01fe70f291: addb %al, (%rax)
>
> 0x7f01fe70f293: addb %al, (%rax)
>
> thread #6: tid = 0x0005, 0x00007f01fe70f49d libc.so.6`__read + 45, stop reason = signal SIGABRT
>
> frame #0: 0x00007f01fe70f49d libc.so.6`__read + 45
>
> -> 0x7f01fe70f49d: addb %al, (%rax)
>
> 0x7f01fe70f49f: addb %al, (%rax)
>
> 0x7f01fe70f4a1: addb %al, (%rax)
>
> 0x7f01fe70f4a3: addb %al, (%rax)
>
> (lldb) thread list
>
> Process 0 stopped
>
> * thread #1: tid = 0x0000, 0x00007f01fe64d267 libc.so.6`gsignal + 55, name = 'corerun', stop reason = signal SIGABRT
>
> thread #2: tid = 0x0001, 0x00007f01fe7138dd libc.so.6`__poll + 45, stop reason = signal SIGABRT
>
> thread #3: tid = 0x0002, 0x00007f01fd27dda0 libpthread.so.0`__pthread_cond_wait + 192, stop reason = signal SIGABRT
>
> thread #4: tid = 0x0003, 0x00007f01fd27e149 libpthread.so.0`__pthread_cond_timedwait + 297, stop reason = signal SIGABRT
>
> thread #5: tid = 0x0004, 0x00007f01fe70f28d libc.so.6`__open64 + 45, stop reason = signal SIGABRT
>
> thread #6: tid = 0x0005, 0x00007f01fe70f49d libc.so.6`__read + 45, stop reason = signal SIGABRT
>
> ------------------------------------------
>
>
>
> gdb /tmp/corerun /tmp/core-corerun-6-1000-1000-20870-1438119958
>
> GNU gdb (Ubuntu 7.9-1ubuntu1) 7.9
>
> Copyright (C) 2015 Free Software Foundation, Inc.
>
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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> This GDB was configured as "x86_64-linux-gnu".
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> Type "show configuration" for configuration details.
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> Reading symbols from /tmp/corerun...done.
>
>
>
> warning: exec file is newer than core file.
>
> [New LWP 20870]
>
> [New LWP 20871]
>
> [New LWP 20874]
>
> [New LWP 20875]
>
> [New LWP 20873]
>
> [New LWP 20872]
>
>
>
> warning: .dynamic section for "/ssd/coreclr/bin/Product/Linux.x64.Debug/libcoreclr.so" is not at the expected address (wrong library or version mismatch?)
>
> [Thread debugging using libthread_db enabled]
>
> Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
>
> Core was generated by `./corerun HelloWorld.exe linux'.
>
> Program terminated with signal SIGABRT, Aborted.
>
> #0 0x00007f01fe64d267 in __GI_raise (sig=sig at entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55
>
> 55 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
>
> (gdb) info threads
>
> Id Target Id Frame
>
> 6 Thread 0x7f01fc42a700 (LWP 20872) 0x00007f01fe70f49d in read () at ../sysdeps/unix/syscall-template.S:81
>
> 5 Thread 0x7f01fbc29700 (LWP 20873) 0x00007f01fe70f28d in open64 () at ../sysdeps/unix/syscall-template.S:81
>
> 4 Thread 0x7f01faafb700 (LWP 20875) pthread_cond_timedwait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:238
>
> 3 Thread 0x7f01fb428700 (LWP 20874) pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
>
> 2 Thread 0x7f01fcc2b700 (LWP 20871) 0x00007f01fe7138dd in poll () at ../sysdeps/unix/syscall-template.S:81
>
> * 1 Thread 0x7f01ff61a740 (LWP 20870) 0x00007f01fe64d267 in __GI_raise (sig=sig at entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55
>
> (gdb)
>
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