linux-kernel - [PATCH v4 1/4] Add BUG

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Mon,  1 Feb 2016 16:35:49 -0700
From:	Jeffrey Merkey <jeffmerkey@...il.com>
To:	linux-kernel@...r.kernel.org
Cc:	hpa@...or.com, jeffmerkey@...il.com, mingo@...hat.com,
	tglx@...utronix.de, x86@...nel.org
Subject: [PATCH v4 1/4] Add BUG_XX() debugging options

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 <jeffmerkey@...il.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