[PATCH 02/31] Add debugger entry points for X86

From: Jeffrey Merkey
Date: Thu Jan 28 2016 - 14:46:26 EST

This patch series adds an export which can be set by system debuggers to
direct the hard lockup and soft lockup detector to trigger a breakpoint
exception and enter a debugger if one is active. It is assumed that if
someone sets this variable, then an breakpoint handler of some sort will
be actively loaded or registered via the notify die handler chain.

This addition is extremely useful for debugging hard and soft lockups
real time and quickly from a console debugger.

Signed-off-by: Jeffrey Merkey <jeffmerkey@xxxxxxxxx>
arch/x86/include/asm/kdebug.h | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/x86/include/asm/kdebug.h b/arch/x86/include/asm/kdebug.h
index e5f5dc9..cbe9004 100644
--- a/arch/x86/include/asm/kdebug.h
+++ b/arch/x86/include/asm/kdebug.h
@@ -3,6 +3,11 @@

#include <linux/notifier.h>

+static inline void arch_breakpoint(void)
+ asm(" int $3");
struct pt_regs;

/* Grossly misnamed. */