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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Memory leak, when executing expressions"
href="https://bugs.llvm.org/show_bug.cgi?id=48237">48237</a>
</td>
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<th>Summary</th>
<td>Memory leak, when executing expressions
</td>
</tr>
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<th>Product</th>
<td>lldb
</td>
</tr>
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<th>Version</th>
<td>11.0
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>All Bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>lldb-dev@lists.llvm.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>mplaneta@os.inf.tu-dresden.de
</td>
</tr>
<tr>
<th>CC</th>
<td>jdevlieghere@apple.com, llvm-bugs@lists.llvm.org
</td>
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<pre>Hello,
When I attach to a process and executes some expressions, lldb allocates memory
to JIT-compile the code inside the process address space. Unfortunately, lldb
does not clean up this memory upon exit.
## How to reproduce
I create a multithreaded program 'victim-malloc' that makes free(malloc()) in a
busy loop. First, I let the program run, then I record the memory map of the
program:
$ cat /proc/$(pidof victim-malloc)/maps > /tmp/a
I attach to the program using lldb and run an expression
$ lldb-11 -p $(pidof victim-malloc)
(lldb) expression -- (int) printf("Hello");
I exit from lldb, record the memory map second time and look at the diff.
$ cat /proc/$(pidof victim-malloc)/maps > /tmp/b
$ diff -p /tmp/a /tmp/b
Here is the result:
*** /tmp/a 2020-11-20 10:21:25.434149021 +0100
--- /tmp/b 2020-11-20 10:22:35.098652870 +0100
***************
*** 57,65 ****
--- 57,69 ----
7f7bc770c000-7f7bc770d000 r--p 0001b000 fd:01 541618
/lib/x86_64-linux-gnu/libpthread-2.31.so
7f7bc770d000-7f7bc770e000 rw-p 0001c000 fd:01 541618
/lib/x86_64-linux-gnu/libpthread-2.31.so
7f7bc770e000-7f7bc7714000 rw-p 00000000 00:00 0
+ 7f7bc7747000-7f7bc7748000 r-xp 00000000 00:00 0
+ 7f7bc7748000-7f7bc7749000 rw-p 00000000 00:00 0
+ 7f7bc7749000-7f7bc774a000 r--p 00000000 00:00 0
7f7bc774a000-7f7bc774b000 r--p 00000000 fd:01 528343
/lib/x86_64-linux-gnu/ld-2.31.so
7f7bc774b000-7f7bc776b000 r-xp 00001000 fd:01 528343
/lib/x86_64-linux-gnu/ld-2.31.so
7f7bc776b000-7f7bc7773000 r--p 00021000 fd:01 528343
/lib/x86_64-linux-gnu/ld-2.31.so
+ 7f7bc7773000-7f7bc7774000 rwxp 00000000 00:00 0
7f7bc7774000-7f7bc7775000 r--p 00029000 fd:01 528343
/lib/x86_64-linux-gnu/ld-2.31.so
7f7bc7775000-7f7bc7776000 rw-p 0002a000 fd:01 528343
/lib/x86_64-linux-gnu/ld-2.31.so
7f7bc7776000-7f7bc7777000 rw-p 00000000 00:00 0
New regions were created by lldb and not cleaned up after exit.</pre>
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