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copied!<p><strong>Remote debugging</strong></p> <p>Alice and Bob should use remote debugging. Bob starts gdbserver:</p> <pre><code>bob@localhost:/home/bob$ gdbserver :2345 ./helloworld </code></pre> <p>And Alice connects to it:</p> <pre><code>alice@localhost:/home/alice$ gdb [...] (gdb) file helloworld Reading symbols from /home/alice/helloworld...done. (gdb) target remote :2345 Remote debugging using :2345 [...] 0x00007fbdc6329af0 in _start () from /lib64/ld-linux-x86-64.so.2 </code></pre> <p><strong>Remote debugging with absolute paths</strong></p> <p>This works in this simple case. However, some more sophistication is requried when Bob uses absolute paths for his shared libraries:</p> <pre><code>bob@localhost:/home/bob$ ls helloworld libmylib.so bob@localhost:/home/bob$ LD_LIBRARY_PATH=/home/bob gdbserver :2345 ./helloworld </code></pre> <p>Now, alice can't find the shared library:</p> <pre><code>alice@localhost:/home/alice$ gdb [...] (gdb) file helloworld Reading symbols from /home/alice/helloworld...done. (gdb) target remote :2345 Remote debugging using :2345 [...] (gdb) break helloWorld() Breakpoint 1 at 0x400480 (gdb) c Continuing. Error while mapping shared library sections: /home/bob/libmylib.so: No such file or directory. </code></pre> <p>To solve this, Alice creates a virtual root folder with links to its on binaries:</p> <pre><code>alice@localhost:/home/alice$ mkdir -p gdb-symbols/home/ alice@localhost:/home/alice$ ln -s /home/alice gdb-symbols/home/bob alice@localhost:/home/alice$ ln -s /lib gdb-symbols/lib alice@localhost:/home/alice$ ln -s /lib64 gdb-symbols/lib64 [and so forth for every shared library that cannot be found...] </code></pre> <p>And is now able to debug with all symbols loaded:</p> <pre><code>alice@localhost:/home/alice$ gdb [...] (gdb) file helloworld Reading symbols from /home/alice/helloworld...done. (gdb) target remote :2345 Remote debugging using :2345 [...] Reading symbols from /home/alice/gdb-symbols/home/bob/libmylib.so...done. Loaded symbols from /home/alice/gdb-symbols/home/bob/libmylib.so (gdb) </code></pre>

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