diff options
Diffstat (limited to 'mm/kmemleak.c')
| -rw-r--r-- | mm/kmemleak.c | 161 |
1 files changed, 134 insertions, 27 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index f3b2a00fe9c1..45eb6217bf38 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -100,6 +100,7 @@ #include <linux/kmemcheck.h> #include <linux/kmemleak.h> +#include <linux/memory_hotplug.h> /* * Kmemleak configuration and common defines. @@ -196,7 +197,9 @@ static atomic_t kmemleak_enabled = ATOMIC_INIT(0); static atomic_t kmemleak_initialized = ATOMIC_INIT(0); /* enables or disables early logging of the memory operations */ static atomic_t kmemleak_early_log = ATOMIC_INIT(1); -/* set if a fata kmemleak error has occurred */ +/* set if a kmemleak warning was issued */ +static atomic_t kmemleak_warning = ATOMIC_INIT(0); +/* set if a fatal kmemleak error has occurred */ static atomic_t kmemleak_error = ATOMIC_INIT(0); /* minimum and maximum address that may be valid pointers */ @@ -228,8 +231,10 @@ static int kmemleak_skip_disable; /* kmemleak operation type for early logging */ enum { KMEMLEAK_ALLOC, + KMEMLEAK_ALLOC_PERCPU, KMEMLEAK_FREE, KMEMLEAK_FREE_PART, + KMEMLEAK_FREE_PERCPU, KMEMLEAK_NOT_LEAK, KMEMLEAK_IGNORE, KMEMLEAK_SCAN_AREA, @@ -259,9 +264,10 @@ static void kmemleak_disable(void); /* * Print a warning and dump the stack trace. */ -#define kmemleak_warn(x...) do { \ - pr_warning(x); \ - dump_stack(); \ +#define kmemleak_warn(x...) do { \ + pr_warning(x); \ + dump_stack(); \ + atomic_set(&kmemleak_warning, 1); \ } while (0) /* @@ -403,8 +409,8 @@ static struct kmemleak_object *lookup_object(unsigned long ptr, int alias) object = prio_tree_entry(node, struct kmemleak_object, tree_node); if (!alias && object->pointer != ptr) { - pr_warning("Found object by alias at 0x%08lx\n", ptr); - dump_stack(); + kmemleak_warn("Found object by alias at 0x%08lx\n", + ptr); dump_object_info(object); object = NULL; } @@ -794,9 +800,13 @@ static void __init log_early(int op_type, const void *ptr, size_t size, unsigned long flags; struct early_log *log; + if (atomic_read(&kmemleak_error)) { + /* kmemleak stopped recording, just count the requests */ + crt_early_log++; + return; + } + if (crt_early_log >= ARRAY_SIZE(early_log)) { - pr_warning("Early log buffer exceeded, " - "please increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE\n"); kmemleak_disable(); return; } @@ -811,8 +821,7 @@ static void __init log_early(int op_type, const void *ptr, size_t size, log->ptr = ptr; log->size = size; log->min_count = min_count; - if (op_type == KMEMLEAK_ALLOC) - log->trace_len = __save_stack_trace(log->trace); + log->trace_len = __save_stack_trace(log->trace); crt_early_log++; local_irq_restore(flags); } @@ -846,6 +855,20 @@ out: rcu_read_unlock(); } +/* + * Log an early allocated block and populate the stack trace. + */ +static void early_alloc_percpu(struct early_log *log) +{ + unsigned int cpu; + const void __percpu *ptr = log->ptr; + + for_each_possible_cpu(cpu) { + log->ptr = per_cpu_ptr(ptr, cpu); + early_alloc(log); + } +} + /** * kmemleak_alloc - register a newly allocated object * @ptr: pointer to beginning of the object @@ -873,6 +896,34 @@ void __ref kmemleak_alloc(const void *ptr, size_t size, int min_count, EXPORT_SYMBOL_GPL(kmemleak_alloc); /** + * kmemleak_alloc_percpu - register a newly allocated __percpu object + * @ptr: __percpu pointer to beginning of the object + * @size: size of the object + * + * This function is called from the kernel percpu allocator when a new object + * (memory block) is allocated (alloc_percpu). It assumes GFP_KERNEL + * allocation. + */ +void __ref kmemleak_alloc_percpu(const void __percpu *ptr, size_t size) +{ + unsigned int cpu; + + pr_debug("%s(0x%p, %zu)\n", __func__, ptr, size); + + /* + * Percpu allocations are only scanned and not reported as leaks + * (min_count is set to 0). + */ + if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) + for_each_possible_cpu(cpu) + create_object((unsigned long)per_cpu_ptr(ptr, cpu), + size, 0, GFP_KERNEL); + else if (atomic_read(&kmemleak_early_log)) + log_early(KMEMLEAK_ALLOC_PERCPU, ptr, size, 0); +} +EXPORT_SYMBOL_GPL(kmemleak_alloc_percpu); + +/** * kmemleak_free - unregister a previously registered object * @ptr: pointer to beginning of the object * @@ -911,6 +962,28 @@ void __ref kmemleak_free_part(const void *ptr, size_t size) EXPORT_SYMBOL_GPL(kmemleak_free_part); /** + * kmemleak_free_percpu - unregister a previously registered __percpu object + * @ptr: __percpu pointer to beginning of the object + * + * This function is called from the kernel percpu allocator when an object + * (memory block) is freed (free_percpu). + */ +void __ref kmemleak_free_percpu(const void __percpu *ptr) +{ + unsigned int cpu; + + pr_debug("%s(0x%p)\n", __func__, ptr); + + if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) + for_each_possible_cpu(cpu) + delete_object_full((unsigned long)per_cpu_ptr(ptr, + cpu)); + else if (atomic_read(&kmemleak_early_log)) + log_early(KMEMLEAK_FREE_PERCPU, ptr, 0, 0); +} +EXPORT_SYMBOL_GPL(kmemleak_free_percpu); + +/** * kmemleak_not_leak - mark an allocated object as false positive * @ptr: pointer to beginning of the object * @@ -963,7 +1036,7 @@ void __ref kmemleak_scan_area(const void *ptr, size_t size, gfp_t gfp) { pr_debug("%s(0x%p)\n", __func__, ptr); - if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) + if (atomic_read(&kmemleak_enabled) && ptr && size && !IS_ERR(ptr)) add_scan_area((unsigned long)ptr, size, gfp); else if (atomic_read(&kmemleak_early_log)) log_early(KMEMLEAK_SCAN_AREA, ptr, size, 0); @@ -1220,9 +1293,9 @@ static void kmemleak_scan(void) #endif /* - * Struct page scanning for each node. The code below is not yet safe - * with MEMORY_HOTPLUG. + * Struct page scanning for each node. */ + lock_memory_hotplug(); for_each_online_node(i) { pg_data_t *pgdat = NODE_DATA(i); unsigned long start_pfn = pgdat->node_start_pfn; @@ -1241,6 +1314,7 @@ static void kmemleak_scan(void) scan_block(page, page + 1, NULL, 1); } } + unlock_memory_hotplug(); /* * Scanning the task stacks (may introduce false negatives). @@ -1467,9 +1541,6 @@ static const struct seq_operations kmemleak_seq_ops = { static int kmemleak_open(struct inode *inode, struct file *file) { - if (!atomic_read(&kmemleak_enabled)) - return -EBUSY; - return seq_open(file, &kmemleak_seq_ops); } @@ -1543,6 +1614,9 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf, int buf_size; int ret; + if (!atomic_read(&kmemleak_enabled)) + return -EBUSY; + buf_size = min(size, (sizeof(buf) - 1)); if (strncpy_from_user(buf, user_buf, buf_size) < 0) return -EFAULT; @@ -1602,20 +1676,24 @@ static const struct file_operations kmemleak_fops = { }; /* - * Perform the freeing of the kmemleak internal objects after waiting for any - * current memory scan to complete. + * Stop the memory scanning thread and free the kmemleak internal objects if + * no previous scan thread (otherwise, kmemleak may still have some useful + * information on memory leaks). */ static void kmemleak_do_cleanup(struct work_struct *work) { struct kmemleak_object *object; + bool cleanup = scan_thread == NULL; mutex_lock(&scan_mutex); stop_scan_thread(); - rcu_read_lock(); - list_for_each_entry_rcu(object, &object_list, object_list) - delete_object_full(object->pointer); - rcu_read_unlock(); + if (cleanup) { + rcu_read_lock(); + list_for_each_entry_rcu(object, &object_list, object_list) + delete_object_full(object->pointer); + rcu_read_unlock(); + } mutex_unlock(&scan_mutex); } @@ -1632,7 +1710,6 @@ static void kmemleak_disable(void) return; /* stop any memory operation tracing */ - atomic_set(&kmemleak_early_log, 0); atomic_set(&kmemleak_enabled, 0); /* check whether it is too early for a kernel thread */ @@ -1659,6 +1736,17 @@ static int kmemleak_boot_config(char *str) } early_param("kmemleak", kmemleak_boot_config); +static void __init print_log_trace(struct early_log *log) +{ + struct stack_trace trace; + + trace.nr_entries = log->trace_len; + trace.entries = log->trace; + + pr_notice("Early log backtrace:\n"); + print_stack_trace(&trace, 2); +} + /* * Kmemleak initialization. */ @@ -1669,6 +1757,7 @@ void __init kmemleak_init(void) #ifdef CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF if (!kmemleak_skip_disable) { + atomic_set(&kmemleak_early_log, 0); kmemleak_disable(); return; } @@ -1681,12 +1770,18 @@ void __init kmemleak_init(void) scan_area_cache = KMEM_CACHE(kmemleak_scan_area, SLAB_NOLEAKTRACE); INIT_PRIO_TREE_ROOT(&object_tree_root); + if (crt_early_log >= ARRAY_SIZE(early_log)) + pr_warning("Early log buffer exceeded (%d), please increase " + "DEBUG_KMEMLEAK_EARLY_LOG_SIZE\n", crt_early_log); + /* the kernel is still in UP mode, so disabling the IRQs is enough */ local_irq_save(flags); - if (!atomic_read(&kmemleak_error)) { + atomic_set(&kmemleak_early_log, 0); + if (atomic_read(&kmemleak_error)) { + local_irq_restore(flags); + return; + } else atomic_set(&kmemleak_enabled, 1); - atomic_set(&kmemleak_early_log, 0); - } local_irq_restore(flags); /* @@ -1701,12 +1796,18 @@ void __init kmemleak_init(void) case KMEMLEAK_ALLOC: early_alloc(log); break; + case KMEMLEAK_ALLOC_PERCPU: + early_alloc_percpu(log); + break; case KMEMLEAK_FREE: kmemleak_free(log->ptr); break; case KMEMLEAK_FREE_PART: kmemleak_free_part(log->ptr, log->size); break; + case KMEMLEAK_FREE_PERCPU: + kmemleak_free_percpu(log->ptr); + break; case KMEMLEAK_NOT_LEAK: kmemleak_not_leak(log->ptr); break; @@ -1720,7 +1821,13 @@ void __init kmemleak_init(void) kmemleak_no_scan(log->ptr); break; default: - WARN_ON(1); + kmemleak_warn("Unknown early log operation: %d\n", + log->op_type); + } + + if (atomic_read(&kmemleak_warning)) { + print_log_trace(log); + atomic_set(&kmemleak_warning, 0); } } } |