feat: Move gdb version to gdblib, do not depend on file exec feature in vmmap

flake.nix

@@ -51,4 +51,4 @@
         // (tarballDrv system)
       );
   };
-}
+}

pwndbg/__init__.py

@@ -35,6 +35,7 @@ import pwndbg.ui
 __version__ = pwndbg.lib.version.__version__
 version = __version__
 
+from pwndbg.gdblib import gdb_version
 from pwndbg.gdblib import prompt
 
 prompt.set_prompt()
@@ -59,7 +60,6 @@ handle SIGSEGV stop   print nopass
 )
 
 # See https://github.com/pwndbg/pwndbg/issues/808
-gdb_version = tuple(map(int, re.search(r"(\d+)[^\d]+(\d+)", gdb.VERSION).groups()))
 if gdb_version[0] <= 9:
     pre_commands += "\nset remote search-memory-packet off"
 

pwndbg/commands/vmmap.py

@@ -4,7 +4,6 @@ Command to print the virtual memory map a la /proc/self/maps.
 from __future__ import annotations
 
 import argparse
-import re
 
 import gdb
 from elftools.elf.constants import SH_FLAGS
@@ -15,6 +14,7 @@ import pwndbg.commands
 import pwndbg.gdblib.elf
 import pwndbg.gdblib.vmmap
 from pwndbg.commands import CommandCategory
+from pwndbg.gdblib import gdb_version
 
 integer_types = (int, gdb.Value)
 
@@ -155,8 +155,6 @@ def vmmap(
     if pwndbg.gdblib.qemu.is_qemu() and not pwndbg.gdblib.qemu.exec_file_supported():
         print("\n[QEMU target detected - vmmap result might not be accurate; see `help vmmap`]")
 
-    gdb_version = tuple(map(int, re.search(r"(\d+)[^\d]+(\d+)", gdb.VERSION).groups()))
-
     # Only GDB versions >=12 report permission info in info proc mappings. On older versions, we fallback on "rwx".
     # See https://github.com/bminor/binutils-gdb/commit/29ef4c0699e1b46d41ade00ae07a54f979ea21cc
     if pwndbg.gdblib.qemu.is_qemu_usermode() and gdb_version[0] < 12:

pwndbg/gdblib/__init__.py

@@ -3,6 +3,10 @@
 
 from __future__ import annotations
 
+import re
+
+import gdb
+
 from pwndbg.gdblib import arch as arch_mod
 from pwndbg.gdblib import config as config_mod
 from pwndbg.gdblib.arch import arch
@@ -12,6 +16,9 @@ regs = None
 
 __all__ = ["ctypes", "memory", "typeinfo"]
 
+# Export parsed GDB version
+gdb_version = tuple(map(int, re.search(r"(\d+)[^\d]+(\d+)", gdb.VERSION).groups()))
+
 
 # TODO: should the imports above be moved here?
 def load_gdblib() -> None:

pwndbg/gdblib/qemu.py

@@ -60,8 +60,8 @@ def is_qemu_kernel() -> bool:
 
 @pwndbg.lib.cache.cache_until("stop")
 def exec_file_supported() -> bool:
-    """Returns ``True`` if the qemu target supports exec file feature.
-    Used in `vmmap` to determine whether qemu supports `info proc mappings`
+    """Returns ``True`` if the remote target understands the 'qXfer:exec-file:read' packet.
+    A check for this feature is done in vmmap code, to warn against running legacy Qemu versions.
     """
     response = gdb.execute("maintenance packet qSupported", to_string=True, from_tty=False)
 

pwndbg/gdblib/vmmap.py

@@ -91,9 +91,12 @@ def get() -> tuple[pwndbg.lib.memory.Page, ...]:
     if is_corefile():
         return tuple(coredump_maps())
 
-    if pwndbg.gdblib.qemu.is_qemu_usermode() and pwndbg.gdblib.qemu.exec_file_supported():
+    proc_maps = None
+    if pwndbg.gdblib.qemu.is_qemu_usermode():
+        # On Qemu < 8.1 info proc maps are not supported. In that case we callback on proc_pid_maps
         proc_maps = info_proc_maps()
-    else:
+
+    if not proc_maps:
         proc_maps = proc_pid_maps()
 
     # The `proc_maps` is usually a tuple of Page objects but it can also be: