This patch series adds config options which can be set during compile to direct the compiler to output a breakpoint instruction anywhere a BUG() or WARN() macro has been placed in the kernel to trigger the system to enter a debugger if a bug is detected by the system. Use of this compile time option also allows conditional breakpoints to be set in the kernel with these currently used macros.
This addition is extremely useful for debugging hard and soft lockups real time and quickly from a console debugger, and other areas of the kernel. Signed-off-by: Jeffrey Merkey <jeffmer...@gmail.com> --- arch/x86/include/asm/bug.h | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h index ba38ebb..df26c2b 100644 --- a/arch/x86/include/asm/bug.h +++ b/arch/x86/include/asm/bug.h @@ -11,6 +11,13 @@ # define __BUG_C0 "2:\t.long 1b - 2b, %c0 - 2b\n" #endif +#ifdef CONFIG_DEBUG_BUG +#define BUG() \ +do { \ + asm volatile("int3"); \ + unreachable(); \ +} while (0) +#else #define BUG() \ do { \ asm volatile("1:\tud2\n" \ @@ -23,7 +30,14 @@ do { \ "i" (sizeof(struct bug_entry))); \ unreachable(); \ } while (0) - +#endif +#else +#ifdef CONFIG_DEBUG_BUG +#define BUG() \ +do { \ + asm volatile("int3"); \ + unreachable(); \ +} while (0) #else #define BUG() \ do { \ @@ -31,6 +45,7 @@ do { \ unreachable(); \ } while (0) #endif +#endif #include <asm-generic/bug.h> -- 1.8.3.1