scripts/gdb/symbols: add specific ko module load command

Patch series "Add GDB memory helper commands", v2.

I've created some GDB commands I think useful when I debug some memory
issues and kernel module issue.

For memory issue, we would like to get slabinfo, slabtrace, page_owner and
vmallocinfo to debug the memory issues.

For module issue, we would like to query kernel module name when we get a
module text address and load module symbol by specific path.

Patch 1-2:
 - Add kernel module related command.
Patch 3-5:
 - Prepares for the memory-related command.
Patch 6-8:
 - Add memory-related commands.


This patch (of 8):

Add lx-symbols <ko_path> command to support add specific
ko module.

Example output like below:
(gdb) lx-symbols mm/kasan/kasan_test.ko
loading @0xffff800002d30000: mm/kasan/kasan_test.ko

Link: https://lkml.kernel.org/r/20230808083020.22254-1-Kuan-Ying.Lee@mediatek.com
Link: https://lkml.kernel.org/r/20230808083020.22254-2-Kuan-Ying.Lee@mediatek.com
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Qun-Wei Lin <qun-wei.lin@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

scripts/gdb/linux/symbols.py

@@ -111,11 +111,12 @@ lx-symbols command."""
         return "{textaddr} {sections}".format(
             textaddr=textaddr, sections="".join(args))
 
-    def load_module_symbols(self, module):
+    def load_module_symbols(self, module, module_file=None):
         module_name = module['name'].string()
         module_addr = str(module['mem'][constants.LX_MOD_TEXT]['base']).split()[0]
 
-        module_file = self._get_module_file(module_name)
+        if not module_file:
+            module_file = self._get_module_file(module_name)
         if not module_file and not self.module_files_updated:
             self._update_module_files()
             module_file = self._get_module_file(module_name)
@@ -138,6 +139,19 @@ lx-symbols command."""
         else:
             gdb.write("no module object found for '{0}'\n".format(module_name))
 
+    def load_ko_symbols(self, mod_path):
+        self.loaded_modules = []
+        module_list = modules.module_list()
+
+        for module in module_list:
+            module_name = module['name'].string()
+            module_pattern = ".*/{0}\.ko(?:.debug)?$".format(
+                module_name.replace("_", r"[_\-]"))
+            if re.match(module_pattern, mod_path) and os.path.exists(mod_path):
+                self.load_module_symbols(module, mod_path)
+                return
+        raise gdb.GdbError("%s is not a valid .ko\n" % mod_path)
+
     def load_all_symbols(self):
         gdb.write("loading vmlinux\n")
 
@@ -176,6 +190,11 @@ lx-symbols command."""
         self.module_files = []
         self.module_files_updated = False
 
+        argv = gdb.string_to_argv(arg)
+        if len(argv) == 1:
+            self.load_ko_symbols(argv[0])
+            return
+
         self.load_all_symbols()
 
         if hasattr(gdb, 'Breakpoint'):