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-rw-r--r--include/linux/bug.h17
-rw-r--r--lib/Kconfig.debug10
-rw-r--r--lib/list_debug.c57
3 files changed, 49 insertions, 35 deletions
diff --git a/include/linux/bug.h b/include/linux/bug.h
index 292d6a10b0c2..baff2e8fc8a8 100644
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -121,4 +121,21 @@ static inline enum bug_trap_type report_bug(unsigned long bug_addr,
}
#endif /* CONFIG_GENERIC_BUG */
+
+/*
+ * Since detected data corruption should stop operation on the affected
+ * structures, this returns false if the corruption condition is found.
+ */
+#define CHECK_DATA_CORRUPTION(condition, fmt, ...) \
+ do { \
+ if (unlikely(condition)) { \
+ if (IS_ENABLED(CONFIG_BUG_ON_DATA_CORRUPTION)) { \
+ pr_err(fmt, ##__VA_ARGS__); \
+ BUG(); \
+ } else \
+ WARN(1, fmt, ##__VA_ARGS__); \
+ return false; \
+ } \
+ } while (0)
+
#endif /* _LINUX_BUG_H */
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 33bc56cf60d7..07a6fac930c5 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1960,6 +1960,16 @@ config TEST_STATIC_KEYS
If unsure, say N.
+config BUG_ON_DATA_CORRUPTION
+ bool "Trigger a BUG when data corruption is detected"
+ select CONFIG_DEBUG_LIST
+ help
+ Select this option if the kernel should BUG when it encounters
+ data corruption in kernel memory structures when they get checked
+ for validity.
+
+ If unsure, say N.
+
source "samples/Kconfig"
source "lib/Kconfig.kgdb"
diff --git a/lib/list_debug.c b/lib/list_debug.c
index 276565fca2a6..7f7bfa55eb6d 100644
--- a/lib/list_debug.c
+++ b/lib/list_debug.c
@@ -20,21 +20,16 @@
bool __list_add_valid(struct list_head *new, struct list_head *prev,
struct list_head *next)
{
- if (unlikely(next->prev != prev)) {
- WARN(1, "list_add corruption. next->prev should be prev (%p), but was %p. (next=%p).\n",
- prev, next->prev, next);
- return false;
- }
- if (unlikely(prev->next != next)) {
- WARN(1, "list_add corruption. prev->next should be next (%p), but was %p. (prev=%p).\n",
- next, prev->next, prev);
- return false;
- }
- if (unlikely(new == prev || new == next)) {
- WARN(1, "list_add double add: new=%p, prev=%p, next=%p.\n",
- new, prev, next);
- return false;
- }
+ CHECK_DATA_CORRUPTION(next->prev != prev,
+ "list_add corruption. next->prev should be prev (%p), but was %p. (next=%p).\n",
+ prev, next->prev, next);
+ CHECK_DATA_CORRUPTION(prev->next != next,
+ "list_add corruption. prev->next should be next (%p), but was %p. (prev=%p).\n",
+ next, prev->next, prev);
+ CHECK_DATA_CORRUPTION(new == prev || new == next,
+ "list_add double add: new=%p, prev=%p, next=%p.\n",
+ new, prev, next);
+
return true;
}
EXPORT_SYMBOL(__list_add_valid);
@@ -46,26 +41,18 @@ bool __list_del_entry_valid(struct list_head *entry)
prev = entry->prev;
next = entry->next;
- if (unlikely(next == LIST_POISON1)) {
- WARN(1, "list_del corruption, %p->next is LIST_POISON1 (%p)\n",
- entry, LIST_POISON1);
- return false;
- }
- if (unlikely(prev == LIST_POISON2)) {
- WARN(1, "list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
- entry, LIST_POISON2);
- return false;
- }
- if (unlikely(prev->next != entry)) {
- WARN(1, "list_del corruption. prev->next should be %p, but was %p\n",
- entry, prev->next);
- return false;
- }
- if (unlikely(next->prev != entry)) {
- WARN(1, "list_del corruption. next->prev should be %p, but was %p\n",
- entry, next->prev);
- return false;
- }
+ CHECK_DATA_CORRUPTION(next == LIST_POISON1,
+ "list_del corruption, %p->next is LIST_POISON1 (%p)\n",
+ entry, LIST_POISON1);
+ CHECK_DATA_CORRUPTION(prev == LIST_POISON2,
+ "list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
+ entry, LIST_POISON2);
+ CHECK_DATA_CORRUPTION(prev->next != entry,
+ "list_del corruption. prev->next should be %p, but was %p\n",
+ entry, prev->next);
+ CHECK_DATA_CORRUPTION(next->prev != entry,
+ "list_del corruption. next->prev should be %p, but was %p\n",
+ entry, next->prev);
return true;
}