diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 15 | ||||
| -rw-r--r-- | lib/list_debug.c | 99 | ||||
| -rw-r--r-- | lib/locking-selftest.c | 66 | ||||
| -rw-r--r-- | lib/lockref.c | 2 | ||||
| -rw-r--r-- | lib/nlattr.c | 2 |
5 files changed, 77 insertions, 107 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index a6c8db1d62f6..9bb7d825ba14 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1218,7 +1218,7 @@ config DEBUG_BUGVERBOSE config DEBUG_LIST bool "Debug linked list manipulation" - depends on DEBUG_KERNEL + depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION help Enable this to turn on extended checks in the linked-list walking routines. @@ -1434,7 +1434,8 @@ config RCU_TRACE select TRACE_CLOCK help This option provides tracing in RCU which presents stats - in debugfs for debugging RCU implementation. + in debugfs for debugging RCU implementation. It also enables + additional tracepoints for ftrace-style event tracing. Say Y here if you want to enable RCU tracing Say N if you are unsure. @@ -1964,6 +1965,16 @@ config TEST_STATIC_KEYS If unsure, say N. +config BUG_ON_DATA_CORRUPTION + bool "Trigger a BUG when data corruption is detected" + select 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 3859bf63561c..7f7bfa55eb6d 100644 --- a/lib/list_debug.c +++ b/lib/list_debug.c @@ -2,8 +2,7 @@ * Copyright 2006, Red Hat, Inc., Dave Jones * Released under the General Public License (GPL). * - * This file contains the linked list implementations for - * DEBUG_LIST. + * This file contains the linked list validation for DEBUG_LIST. */ #include <linux/export.h> @@ -13,88 +12,48 @@ #include <linux/rculist.h> /* - * Insert a new entry between two known consecutive entries. - * - * This is only for internal list manipulation where we know - * the prev/next entries already! + * Check that the data structures for the list manipulations are reasonably + * valid. Failures here indicate memory corruption (and possibly an exploit + * attempt). */ -void __list_add(struct list_head *new, - struct list_head *prev, - struct list_head *next) +bool __list_add_valid(struct list_head *new, struct list_head *prev, + struct list_head *next) { - WARN(next->prev != prev, - "list_add corruption. next->prev should be " - "prev (%p), but was %p. (next=%p).\n", + 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); - WARN(prev->next != next, - "list_add corruption. prev->next should be " - "next (%p), but was %p. (prev=%p).\n", + 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); - WARN(new == prev || new == next, - "list_add double add: new=%p, prev=%p, next=%p.\n", - new, prev, next); - next->prev = new; - new->next = next; - new->prev = prev; - WRITE_ONCE(prev->next, new); + 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); +EXPORT_SYMBOL(__list_add_valid); -void __list_del_entry(struct list_head *entry) +bool __list_del_entry_valid(struct list_head *entry) { struct list_head *prev, *next; prev = entry->prev; next = entry->next; - if (WARN(next == LIST_POISON1, + CHECK_DATA_CORRUPTION(next == LIST_POISON1, "list_del corruption, %p->next is LIST_POISON1 (%p)\n", - entry, LIST_POISON1) || - WARN(prev == LIST_POISON2, + entry, LIST_POISON1); + CHECK_DATA_CORRUPTION(prev == LIST_POISON2, "list_del corruption, %p->prev is LIST_POISON2 (%p)\n", - entry, LIST_POISON2) || - WARN(prev->next != entry, - "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)) - return; - - __list_del(prev, next); -} -EXPORT_SYMBOL(__list_del_entry); + 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; -/** - * list_del - deletes entry from list. - * @entry: the element to delete from the list. - * Note: list_empty on entry does not return true after this, the entry is - * in an undefined state. - */ -void list_del(struct list_head *entry) -{ - __list_del_entry(entry); - entry->next = LIST_POISON1; - entry->prev = LIST_POISON2; -} -EXPORT_SYMBOL(list_del); - -/* - * RCU variants. - */ -void __list_add_rcu(struct list_head *new, - struct list_head *prev, struct list_head *next) -{ - WARN(next->prev != prev, - "list_add_rcu corruption. next->prev should be prev (%p), but was %p. (next=%p).\n", - prev, next->prev, next); - WARN(prev->next != next, - "list_add_rcu corruption. prev->next should be next (%p), but was %p. (prev=%p).\n", - next, prev->next, prev); - new->next = next; - new->prev = prev; - rcu_assign_pointer(list_next_rcu(prev), new); - next->prev = new; } -EXPORT_SYMBOL(__list_add_rcu); +EXPORT_SYMBOL(__list_del_entry_valid); diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index 872a15a2a637..f3a217ea0388 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -980,23 +980,23 @@ static void dotest(void (*testcase_fn)(void), int expected, int lockclass_mask) #ifndef CONFIG_PROVE_LOCKING if (expected == FAILURE && debug_locks) { expected_testcase_failures++; - printk("failed|"); + pr_cont("failed|"); } else #endif if (debug_locks != expected) { unexpected_testcase_failures++; - printk("FAILED|"); + pr_cont("FAILED|"); dump_stack(); } else { testcase_successes++; - printk(" ok |"); + pr_cont(" ok |"); } testcase_total++; if (debug_locks_verbose) - printk(" lockclass mask: %x, debug_locks: %d, expected: %d\n", + pr_cont(" lockclass mask: %x, debug_locks: %d, expected: %d\n", lockclass_mask, debug_locks, expected); /* * Some tests (e.g. double-unlock) might corrupt the preemption @@ -1021,26 +1021,26 @@ static inline void print_testname(const char *testname) #define DO_TESTCASE_1(desc, name, nr) \ print_testname(desc"/"#nr); \ dotest(name##_##nr, SUCCESS, LOCKTYPE_RWLOCK); \ - printk("\n"); + pr_cont("\n"); #define DO_TESTCASE_1B(desc, name, nr) \ print_testname(desc"/"#nr); \ dotest(name##_##nr, FAILURE, LOCKTYPE_RWLOCK); \ - printk("\n"); + pr_cont("\n"); #define DO_TESTCASE_3(desc, name, nr) \ print_testname(desc"/"#nr); \ dotest(name##_spin_##nr, FAILURE, LOCKTYPE_SPIN); \ dotest(name##_wlock_##nr, FAILURE, LOCKTYPE_RWLOCK); \ dotest(name##_rlock_##nr, SUCCESS, LOCKTYPE_RWLOCK); \ - printk("\n"); + pr_cont("\n"); #define DO_TESTCASE_3RW(desc, name, nr) \ print_testname(desc"/"#nr); \ dotest(name##_spin_##nr, FAILURE, LOCKTYPE_SPIN|LOCKTYPE_RWLOCK);\ dotest(name##_wlock_##nr, FAILURE, LOCKTYPE_RWLOCK); \ dotest(name##_rlock_##nr, SUCCESS, LOCKTYPE_RWLOCK); \ - printk("\n"); + pr_cont("\n"); #define DO_TESTCASE_6(desc, name) \ print_testname(desc); \ @@ -1050,7 +1050,7 @@ static inline void print_testname(const char *testname) dotest(name##_mutex, FAILURE, LOCKTYPE_MUTEX); \ dotest(name##_wsem, FAILURE, LOCKTYPE_RWSEM); \ dotest(name##_rsem, FAILURE, LOCKTYPE_RWSEM); \ - printk("\n"); + pr_cont("\n"); #define DO_TESTCASE_6_SUCCESS(desc, name) \ print_testname(desc); \ @@ -1060,7 +1060,7 @@ static inline void print_testname(const char *testname) dotest(name##_mutex, SUCCESS, LOCKTYPE_MUTEX); \ dotest(name##_wsem, SUCCESS, LOCKTYPE_RWSEM); \ dotest(name##_rsem, SUCCESS, LOCKTYPE_RWSEM); \ - printk("\n"); + pr_cont("\n"); /* * 'read' variant: rlocks must not trigger. @@ -1073,7 +1073,7 @@ static inline void print_testname(const char *testname) dotest(name##_mutex, FAILURE, LOCKTYPE_MUTEX); \ dotest(name##_wsem, FAILURE, LOCKTYPE_RWSEM); \ dotest(name##_rsem, FAILURE, LOCKTYPE_RWSEM); \ - printk("\n"); + pr_cont("\n"); #define DO_TESTCASE_2I(desc, name, nr) \ DO_TESTCASE_1("hard-"desc, name##_hard, nr); \ @@ -1726,25 +1726,25 @@ static void ww_tests(void) dotest(ww_test_fail_acquire, SUCCESS, LOCKTYPE_WW); dotest(ww_test_normal, SUCCESS, LOCKTYPE_WW); dotest(ww_test_unneeded_slow, FAILURE, LOCKTYPE_WW); - printk("\n"); + pr_cont("\n"); print_testname("ww contexts mixing"); dotest(ww_test_two_contexts, FAILURE, LOCKTYPE_WW); dotest(ww_test_diff_class, FAILURE, LOCKTYPE_WW); - printk("\n"); + pr_cont("\n"); print_testname("finishing ww context"); dotest(ww_test_context_done_twice, FAILURE, LOCKTYPE_WW); dotest(ww_test_context_unlock_twice, FAILURE, LOCKTYPE_WW); dotest(ww_test_context_fini_early, FAILURE, LOCKTYPE_WW); dotest(ww_test_context_lock_after_done, FAILURE, LOCKTYPE_WW); - printk("\n"); + pr_cont("\n"); print_testname("locking mismatches"); dotest(ww_test_object_unlock_twice, FAILURE, LOCKTYPE_WW); dotest(ww_test_object_lock_unbalanced, FAILURE, LOCKTYPE_WW); dotest(ww_test_object_lock_stale_context, FAILURE, LOCKTYPE_WW); - printk("\n"); + pr_cont("\n"); print_testname("EDEADLK handling"); dotest(ww_test_edeadlk_normal, SUCCESS, LOCKTYPE_WW); @@ -1757,11 +1757,11 @@ static void ww_tests(void) dotest(ww_test_edeadlk_acquire_more_edeadlk_slow, FAILURE, LOCKTYPE_WW); dotest(ww_test_edeadlk_acquire_wrong, FAILURE, LOCKTYPE_WW); dotest(ww_test_edeadlk_acquire_wrong_slow, FAILURE, LOCKTYPE_WW); - printk("\n"); + pr_cont("\n"); print_testname("spinlock nest unlocked"); dotest(ww_test_spin_nest_unlocked, FAILURE, LOCKTYPE_WW); - printk("\n"); + pr_cont("\n"); printk(" -----------------------------------------------------\n"); printk(" |block | try |context|\n"); @@ -1771,25 +1771,25 @@ static void ww_tests(void) dotest(ww_test_context_block, FAILURE, LOCKTYPE_WW); dotest(ww_test_context_try, SUCCESS, LOCKTYPE_WW); dotest(ww_test_context_context, SUCCESS, LOCKTYPE_WW); - printk("\n"); + pr_cont("\n"); print_testname("try"); dotest(ww_test_try_block, FAILURE, LOCKTYPE_WW); dotest(ww_test_try_try, SUCCESS, LOCKTYPE_WW); dotest(ww_test_try_context, FAILURE, LOCKTYPE_WW); - printk("\n"); + pr_cont("\n"); print_testname("block"); dotest(ww_test_block_block, FAILURE, LOCKTYPE_WW); dotest(ww_test_block_try, SUCCESS, LOCKTYPE_WW); dotest(ww_test_block_context, FAILURE, LOCKTYPE_WW); - printk("\n"); + pr_cont("\n"); print_testname("spinlock"); dotest(ww_test_spin_block, FAILURE, LOCKTYPE_WW); dotest(ww_test_spin_try, SUCCESS, LOCKTYPE_WW); dotest(ww_test_spin_context, FAILURE, LOCKTYPE_WW); - printk("\n"); + pr_cont("\n"); } void locking_selftest(void) @@ -1829,32 +1829,32 @@ void locking_selftest(void) printk(" --------------------------------------------------------------------------\n"); print_testname("recursive read-lock"); - printk(" |"); + pr_cont(" |"); dotest(rlock_AA1, SUCCESS, LOCKTYPE_RWLOCK); - printk(" |"); + pr_cont(" |"); dotest(rsem_AA1, FAILURE, LOCKTYPE_RWSEM); - printk("\n"); + pr_cont("\n"); print_testname("recursive read-lock #2"); - printk(" |"); + pr_cont(" |"); dotest(rlock_AA1B, SUCCESS, LOCKTYPE_RWLOCK); - printk(" |"); + pr_cont(" |"); dotest(rsem_AA1B, FAILURE, LOCKTYPE_RWSEM); - printk("\n"); + pr_cont("\n"); print_testname("mixed read-write-lock"); - printk(" |"); + pr_cont(" |"); dotest(rlock_AA2, FAILURE, LOCKTYPE_RWLOCK); - printk(" |"); + pr_cont(" |"); dotest(rsem_AA2, FAILURE, LOCKTYPE_RWSEM); - printk("\n"); + pr_cont("\n"); print_testname("mixed write-read-lock"); - printk(" |"); + pr_cont(" |"); dotest(rlock_AA3, FAILURE, LOCKTYPE_RWLOCK); - printk(" |"); + pr_cont(" |"); dotest(rsem_AA3, FAILURE, LOCKTYPE_RWSEM); - printk("\n"); + pr_cont("\n"); printk(" --------------------------------------------------------------------------\n"); diff --git a/lib/lockref.c b/lib/lockref.c index 5a92189ad711..c4bfcb8836cd 100644 --- a/lib/lockref.c +++ b/lib/lockref.c @@ -20,7 +20,7 @@ if (likely(old.lock_count == prev.lock_count)) { \ SUCCESS; \ } \ - cpu_relax_lowlatency(); \ + cpu_relax(); \ } \ } while (0) diff --git a/lib/nlattr.c b/lib/nlattr.c index fce1e9afc6d9..b42b8577fc23 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -14,7 +14,7 @@ #include <linux/types.h> #include <net/netlink.h> -static const u16 nla_attr_minlen[NLA_TYPE_MAX+1] = { +static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = { [NLA_U8] = sizeof(u8), [NLA_U16] = sizeof(u16), [NLA_U32] = sizeof(u32), |
