libcdb.unstrip_libc: debug symbols are fetched only if not present (Gallopsled#2374)

* libcdb.unstrip_libc: debug symbols are fetched only if not present

* Usage of `ELF.debuginfo` to check if debug symbols exist

closes Gallopsled#2324

---------

Signed-off-by: sswastik02 <[email protected]>

* Add CHANGELOG

Signed-off-by: sswastik02 <[email protected]>

---------

Signed-off-by: sswastik02 <[email protected]>

Author: sswastik02

CHANGELOG.md

@@ -72,8 +72,10 @@ The table below shows which release corresponds to each branch, and what date th
 ## 4.14.0 (`dev`)
 
 - [#2356][2356] Add local libc database provider for libcdb
+- [#2374][2374] libcdb.unstrip_libc: debug symbols are fetched only if not present
 
 [2356]: https://github.com/Gallopsled/pwntools/pull/2356
+[2374]: https://github.com/Gallopsled/pwntools/pull/2374
 
 ## 4.13.0 (`beta`)
 

pwnlib/libcdb.py

@@ -291,6 +291,10 @@ def unstrip_libc(filename):
         log.warn_once('Given libc does not have a buildid. Cannot look for debuginfo to unstrip.')
         return False
 
+    if libc.debuginfo:
+        log.debug('Given libc already contains debug information. Skipping unstrip.')
+        return True
+
     log.debug('Trying debuginfod servers: %r', DEBUGINFOD_SERVERS)
 
     for server_url in DEBUGINFOD_SERVERS: