How do I get the backtrace for all the threads in GDB?

Question

Is there an equivalent command in GDB to that of WinDbg's !process 0 7?

I want to extract all the threads in a dump file along with their backtraces in GDB. info threads doesn't output the stack traces. So, is there a command that does?

The corresponding command for LLDB [is `bt all`](http://lldb.llvm.org/lldb-gdb.html) — in case someone found this via Google (who thinks GDB == LLDB). — kennytm, Oct 26 '16 at 17:56
With python the following works " (gdb) python for thread in gdb.selected_inferior().threads(): thread.switch(); print(thread.num);gdb.execute('where')" — Talespin_Kit, Apr 08 '20 at 07:08
In fact, I created the exact question: https://stackoverflow.com/questions/67820406/how-do-i-get-the-backtrace-for-all-the-threads-in-lldb — Bruno Alexandre Rosa, Jun 03 '21 at 11:14

score 381 · Answer 1 · edited Jul 27 '19 at 09:58

381

Generally, the backtrace is used to get the stack of the current thread, but if there is a necessity to get the stack trace of all the threads, use the following command.

thread apply all bt

edited Jul 27 '19 at 09:58

Peter Mortensen

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answered Apr 10 '14 at 06:36

Sharad

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To save the output to a file: `gdb -ex "thread apply all bt" -ex "quit" > output.log` – Doomsday Mar 28 '18 at 09:32
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You can shorten this to `t a a bt` – qbolec Mar 13 '20 at 09:25
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The command in @Doomsday comment hangs for me. Better try with `gdb -ex "thread apply all bt" -ex "detach" -ex "quit" > output.log`, to avoid a question from gdb that blocks the command waiting for input. – Mariano Paniga Aug 12 '20 at 12:52
The more generic syntax is `thread apply [threadno] [all] args`, where `[threadno]` can also be a space-separated list of thread identifiers (e.g. `2 3 4`), or a range (e.g. `2-6`). – nnunes Sep 20 '21 at 16:32
@MarianoPaniga, or use `--batch`. – Stephane Chazelas Oct 27 '21 at 09:15

score 68 · Answer 2 · edited Jul 27 '19 at 09:57

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Is there a command that does?

thread apply all where

edited Jul 27 '19 at 09:57

Peter Mortensen

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answered Aug 22 '13 at 22:46

Employed Russian

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A synonym for `backtrace`. – erik258 Nov 28 '17 at 15:21
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Just tried, this is not a synonym for backtrace. – Vipin May 01 '21 at 10:48
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From `info gdb where`: *The names 'where' and 'info stack' (abbreviated 'info s') are additional aliases for 'backtrace'.* – Stephane Chazelas Oct 27 '21 at 09:13

score 17 · Answer 3 · answered May 18 '21 at 08:23

When debugging with several threads, it is also useful to switch to a particular thread number and get the backtrace for that thread only.

From the GNU GDB threads documentation

For debugging purposes, GDB associates its own thread number--a small integer assigned in thread-creation order--with each thread in your program.

Usage:

info threads

Then identify the thread that you want to look at.

thread <thread_id>

Finally, use backtrace for just that thread:

bt

score -2 · Answer 4 · answered Feb 24 '22 at 11:52

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If your process is running:

pstack $pid

answered Feb 24 '22 at 11:52

EricRen

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Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer). – Community Feb 25 '22 at 08:46

How do I get the backtrace for all the threads in GDB?

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