kernel/lib: add additional debug capabilities for data corruption
Data corruptions in the kernel often end up in system crashes that
are easier to debug closer to the time of detection. Specifically,
if we do not panic immediately after lock or list corruptions have been
detected, the problem context is lost in the ensuing system mayhem.
Add support for allowing system crash immediately after such corruptions
are detected. The CONFIG option controls the enabling/disabling of the
feature.
Change-Id: I9b2eb62da506a13007acff63e85e9515145909ff
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index fa9c7cd..7ca0012 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2038,6 +2038,13 @@
If unsure, say N.
+config PANIC_ON_DATA_CORRUPTION
+ bool "Cause a Kernel Panic When Data Corruption is detected"
+ help
+ Select this option to upgrade warnings for potentially
+ recoverable data corruption scenarios to system-halting panics,
+ for easier detection and debug.
+
source "samples/Kconfig"
source "lib/Kconfig.kgdb"
diff --git a/lib/list_debug.c b/lib/list_debug.c
index 3859bf6..7a5c1c0 100644
--- a/lib/list_debug.c
+++ b/lib/list_debug.c
@@ -11,6 +11,7 @@
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/rculist.h>
+#include <linux/bug.h>
/*
* Insert a new entry between two known consecutive entries.
@@ -34,6 +35,10 @@
WARN(new == prev || new == next,
"list_add double add: new=%p, prev=%p, next=%p.\n",
new, prev, next);
+
+ BUG_ON((prev->next != next || next->prev != prev ||
+ new == prev || new == next) && PANIC_CORRUPTION);
+
next->prev = new;
new->next = next;
new->prev = prev;
@@ -58,9 +63,11 @@
"list_del corruption. prev->next should be %p, "
"but was %p\n", entry, prev->next) ||
WARN(next->prev != entry,
- "list_del corruption. next->prev should be %p, "
- "but was %p\n", entry, next->prev))
+ "list_del corruption. next->prev should be %p, but was %p\n",
+ entry, next->prev)) {
+ BUG_ON(PANIC_CORRUPTION);
return;
+ }
__list_del(prev, next);
}