x86,kgdb: Add low level debug hook

The only way the debugger can handle a trap in inside rcu_lock, notify_die, or atomic_notifier_call_chain without a triple fault is to have a low level "first opportunity handler" in the int3 exception handler. Generally this will be something the vast majority of folks will not need, but for those who need it, it is added as a kernel .config option called KGDB_LOW_LEVEL_TRAP.

Jason Wessel committed 16 years ago

Commit f503b5a1 parent 98ec1876 files · +41 −2Browse files

Showing the changes to kernel/debug/debug_core.c (1 of 6 files). Show all

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kernel/debug/debug_core.c+1−1

@@ -66,7 +66,7 @@ int kgdb_connected; · 65 unmodified lines
66	EXPORT_SYMBOL_GPL(kgdb_connected);	66	EXPORT_SYMBOL_GPL(kgdb_connected);
67		67
68	/* All the KGDB handlers are installed */	68	/* All the KGDB handlers are installed */
69	static int kgdb_io_module_registered;	69	int kgdb_io_module_registered;
70		70
71	/* Guard for recursive entry */	71	/* Guard for recursive entry */
72	static int exception_level;	72	static int exception_level;