diff options
| -rw-r--r-- | include/linux/bug.h | 17 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 10 | ||||
| -rw-r--r-- | lib/list_debug.c | 57 |
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; } |