summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/traps.c
diff options
context:
space:
mode:
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/traps.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/traps.c')
-rw-r--r--arch/x86/kernel/traps.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 02cfb9b8f5b..7eaad4c5110 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -15,6 +15,7 @@
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/kdebug.h>
+#include <linux/kgdb.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ptrace.h>
@@ -451,6 +452,11 @@ void restart_nmi(void)
/* May run on IST stack. */
dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
{
+#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
+ if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
+ == NOTIFY_STOP)
+ return;
+#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
#ifdef CONFIG_KPROBES
if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
== NOTIFY_STOP)