scripts/gdb: fix lx-symbols command for arm64 LLVM

lx-symbols assumes that module's .text sections is located at
`module->mem[MOD_TEXT].base` and passes it to add-symbol-file command.
However, .text section follows after .plt section in modules built by LLVM
toolchain for arm64 target.  Symbol addresses are skewed in GDB.

Fix this issue by using the address of .text section stored in
`module->sect_attrs`.

Link: https://lkml.kernel.org/r/20230801121052.2475183-1-koudai@google.com
Signed-off-by: Koudai Iwahori <koudai@google.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/scripts/gdb/linux/symbols.py b/scripts/gdb/linux/symbols.py
index fdad3f32c7476826aa4b35369917ddb50c646730..c8047f4441e60ea944ae6fccedf0e4d0d7632dcd 100644 (file)
--- a/scripts/gdb/linux/symbols.py
+++ b/scripts/gdb/linux/symbols.py
@@ -89,23 +89,27 @@ lx-symbols command."""
                 return name
         return None
 
-    def _section_arguments(self, module):
+    def _section_arguments(self, module, module_addr):
         try:
             sect_attrs = module['sect_attrs'].dereference()
         except gdb.error:
-            return ""
+            return str(module_addr)
+
         attrs = sect_attrs['attrs']
         section_name_to_address = {
             attrs[n]['battr']['attr']['name'].string(): attrs[n]['address']
             for n in range(int(sect_attrs['nsections']))}
+
+        textaddr = section_name_to_address.get(".text", module_addr)
         args = []
         for section_name in [".data", ".data..read_mostly", ".rodata", ".bss",
-                             ".text", ".text.hot", ".text.unlikely"]:
+                             ".text.hot", ".text.unlikely"]:
             address = section_name_to_address.get(section_name)
             if address:
                 args.append(" -s {name} {addr}".format(
                     name=section_name, addr=str(address)))
-        return "".join(args)
+        return "{textaddr} {sections}".format(
+            textaddr=textaddr, sections="".join(args))
 
     def load_module_symbols(self, module):
         module_name = module['name'].string()
@@ -125,10 +129,9 @@ lx-symbols command."""
                 module_addr = hex(int(module_addr, 0) + plt_offset + plt_size)
             gdb.write("loading @{addr}: {filename}\n".format(
                 addr=module_addr, filename=module_file))
-            cmdline = "add-symbol-file {filename} {addr}{sections}".format(
+            cmdline = "add-symbol-file {filename} {sections}".format(
                 filename=module_file,
-                addr=module_addr,
-                sections=self._section_arguments(module))
+                sections=self._section_arguments(module, module_addr))
             gdb.execute(cmdline, to_string=True)
             if module_name not in self.loaded_modules:
                 self.loaded_modules.append(module_name)