A simple kernel module was used to create concurrent WARNs and BUGs:
http://ozlabs.org/~anton/junkcode/warnstorm.tar.gz
Signed-off-by: Anton Blanchard <an...@samba.org>
---
arch/powerpc/kernel/traps.c | 44 ++++++++++++++++++++++++++++++++++++--------
1 file changed, 36 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 4cc1e72..f779557 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1114,6 +1114,39 @@ static int emulate_math(struct pt_regs *regs)
static inline int emulate_math(struct pt_regs *regs) { return -1; }
#endif
+static bool __report_bug(unsigned long bugaddr, struct pt_regs *regs)
+{
+ const struct bug_entry *bug;
+ unsigned long flags;
+ int err;
+
+ if (!is_valid_bugaddr(bugaddr))
+ return false;
+
+ bug = find_bug(bugaddr);
+ if (!bug)
+ return false;
+
+ if (is_warning_bug(bug)) {
+ die_spin_lock_irqsave(flags);
+ report_bug(bugaddr, regs);
+ die_spin_unlock_irqrestore(flags);
+
+ regs->nip += 4;
+
+ return true;
+ }
+
+ flags = oops_begin(regs);
+ report_bug(bugaddr, regs);
+ err = SIGTRAP;
+ if (__die("Exception in kernel mode", regs, err))
+ err = 0;
+ oops_end(flags, regs, err);
+
+ return true;
+}
+
void __kprobes program_check_exception(struct pt_regs *regs)
{
enum ctx_state prev_state = exception_enter();
@@ -1138,11 +1171,9 @@ void __kprobes program_check_exception(struct pt_regs
*regs)
== NOTIFY_STOP)
goto bail;
- if (!(regs->msr & MSR_PR) && /* not user-mode */
- report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
- regs->nip += 4;
+ if (!user_mode(regs) && __report_bug(regs->nip, regs))
goto bail;
- }
+
_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
goto bail;
}
@@ -1157,11 +1188,8 @@ void __kprobes program_check_exception(struct pt_regs
*regs)
* - A tend is illegally attempted.
* - writing a TM SPR when transactional.
*/
- if (!user_mode(regs) &&
- report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
- regs->nip += 4;
+ if (!user_mode(regs) && __report_bug(regs->nip, regs))
goto bail;
- }
/* If usermode caused this, it's done something illegal and
* gets a SIGILL slap on the wrist. We call it an illegal
* operand to distinguish from the instruction just being bad
--
2.1.0
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
