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authorJason Wessel <jason.wessel@windriver.com>2010-05-20 21:04:25 -0500
committerJason Wessel <jason.wessel@windriver.com>2010-05-20 21:04:25 -0500
commitf503b5ae53cb557ac351a668fcac1baab1cef0db (patch)
treeb2deb02cec90cb18a075b3a49e6de949db374c77 /arch/x86/kernel/kgdb.c
parent98ec1878cacb393975cba64f7392eece81716cb4 (diff)
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. CC: Ingo Molnar <mingo@elte.hu> CC: Thomas Gleixner <tglx@linutronix.de> CC: H. Peter Anvin <hpa@zytor.com> CC: x86@kernel.org Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Diffstat (limited to 'arch/x86/kernel/kgdb.c')
-rw-r--r--arch/x86/kernel/kgdb.c22
1 files changed, 21 insertions, 1 deletions
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index acba5716993..95b89d4cb8f 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -538,7 +538,7 @@ static int __kgdb_notify(struct die_args *args, unsigned long cmd)
return NOTIFY_DONE;
}
- if (kgdb_handle_exception(args->trapnr, args->signr, args->err, regs))
+ if (kgdb_handle_exception(args->trapnr, args->signr, cmd, regs))
return NOTIFY_DONE;
/* Must touch watchdog before return to normal operation */
@@ -546,6 +546,26 @@ static int __kgdb_notify(struct die_args *args, unsigned long cmd)
return NOTIFY_STOP;
}
+#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
+int kgdb_ll_trap(int cmd, const char *str,
+ struct pt_regs *regs, long err, int trap, int sig)
+{
+ struct die_args args = {
+ .regs = regs,
+ .str = str,
+ .err = err,
+ .trapnr = trap,
+ .signr = sig,
+
+ };
+
+ if (!kgdb_io_module_registered)
+ return NOTIFY_DONE;
+
+ return __kgdb_notify(&args, cmd);
+}
+#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
+
static int
kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
{