From 82b41e3d6113291258c65281144bce946553dfed Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Tue, 17 Feb 2015 13:46:52 -0800 Subject: scripts/gdb: add automatic symbol reloading on module insertion This installs a silent breakpoint on the do_init_module function. The breakpoint handler will try to load symbols from the module files found during lx-symbols execution. This way, breakpoints can be set to module initialization functions, and there is no need to explicitly call lx-symbols after (re-)loading a module. Signed-off-by: Jan Kiszka Cc: Thomas Gleixner Cc: Jason Wessel Cc: Andi Kleen Cc: Ben Widawsky Cc: Borislav Petkov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds diff --git a/scripts/gdb/linux/symbols.py b/scripts/gdb/linux/symbols.py index bd21a96..139841f 100644 --- a/scripts/gdb/linux/symbols.py +++ b/scripts/gdb/linux/symbols.py @@ -19,6 +19,30 @@ import string from linux import modules, utils +if hasattr(gdb, 'Breakpoint'): + class LoadModuleBreakpoint(gdb.Breakpoint): + def __init__(self, spec, gdb_command): + super(LoadModuleBreakpoint, self).__init__(spec, internal=True) + self.silent = True + self.gdb_command = gdb_command + + def stop(self): + module = gdb.parse_and_eval("mod") + module_name = module['name'].string() + cmd = self.gdb_command + + # enforce update if object file is not found + cmd.module_files_updated = False + + if module_name in cmd.loaded_modules: + gdb.write("refreshing all symbols to reload module " + "'{0}'\n".format(module_name)) + cmd.load_all_symbols() + else: + cmd.load_module_symbols(module) + return False + + class LxSymbols(gdb.Command): """(Re-)load symbols of Linux kernel and currently loaded modules. @@ -30,6 +54,8 @@ lx-symbols command.""" module_paths = [] module_files = [] module_files_updated = False + loaded_modules = [] + breakpoint = None def __init__(self): super(LxSymbols, self).__init__("lx-symbols", gdb.COMMAND_FILES, @@ -87,6 +113,8 @@ lx-symbols command.""" addr=module_addr, sections=self._section_arguments(module)) gdb.execute(cmdline, to_string=True) + if not module_name in self.loaded_modules: + self.loaded_modules.append(module_name) else: gdb.write("no module object found for '{0}'\n".format(module_name)) @@ -104,6 +132,7 @@ lx-symbols command.""" gdb.execute("symbol-file", to_string=True) gdb.execute("symbol-file vmlinux") + self.loaded_modules = [] module_list = modules.ModuleList() if not module_list: gdb.write("no modules found\n") @@ -123,5 +152,15 @@ lx-symbols command.""" self.load_all_symbols() + if hasattr(gdb, 'Breakpoint'): + if not self.breakpoint is None: + self.breakpoint.delete() + self.breakpoint = None + self.breakpoint = LoadModuleBreakpoint( + "kernel/module.c:do_init_module", self) + else: + gdb.write("Note: symbol update on module loading not supported " + "with this gdb version\n") + LxSymbols() -- cgit v0.10.2