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Merge branch 'kmemleak' of git://linux-arm.org/linux-2.6

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* 'kmemleak' of git://linux-arm.org/linux-2.6:
  kmemleak: Remove alloc_bootmem annotations introduced in the past
  kmemleak: Add callbacks to the bootmem allocator
  kmemleak: Allow partial freeing of memory blocks
  kmemleak: Trace the kmalloc_large* functions in slub
  kmemleak: Scan objects allocated during a scanning episode
  kmemleak: Do not acquire scan_mutex in kmemleak_open()
  kmemleak: Remove the reported leaks number limitation
  kmemleak: Add more cond_resched() calls in the scanning thread
  kmemleak: Renice the scanning thread to +10
This commit is contained in:
Linus Torvalds 2009-07-12 12:24:35 -07:00
commit 7638d5322b
7 changed files with 185 additions and 94 deletions
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4
include/linux/kmemleak.h
View File

@ -27,6 +27,7 @@ extern void kmemleak_init(void);
extern void kmemleak_alloc(const void *ptr, size_t size, int min_count,
gfp_t gfp);
extern void kmemleak_free(const void *ptr);
extern void kmemleak_free_part(const void *ptr, size_t size);
extern void kmemleak_padding(const void *ptr, unsigned long offset,
size_t size);
extern void kmemleak_not_leak(const void *ptr);
@ -71,6 +72,9 @@ static inline void kmemleak_alloc_recursive(const void *ptr, size_t size,
static inline void kmemleak_free(const void *ptr)
{
}
static inline void kmemleak_free_part(const void *ptr, size_t size)
{
}
static inline void kmemleak_free_recursive(const void *ptr, unsigned long flags)
{
}

2
include/linux/slub_def.h
View File

@ -11,6 +11,7 @@
#include <linux/workqueue.h>
#include <linux/kobject.h>
#include <linux/kmemtrace.h>
#include <linux/kmemleak.h>
enum stat_item {
ALLOC_FASTPATH, /* Allocation from cpu slab */
@ -233,6 +234,7 @@ static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
unsigned int order = get_order(size);
void *ret = (void *) __get_free_pages(flags | __GFP_COMP, order);
kmemleak_alloc(ret, size, 1, flags);
trace_kmalloc(_THIS_IP_, ret, size, PAGE_SIZE << order, flags);
return ret;

7
kernel/pid.c
View File

@ -36,7 +36,6 @@
#include <linux/pid_namespace.h>
#include <linux/init_task.h>
#include <linux/syscalls.h>
#include <linux/kmemleak.h>
#define pid_hashfn(nr, ns) \
hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift)
@ -513,12 +512,6 @@ void __init pidhash_init(void)
pid_hash = alloc_bootmem(pidhash_size * sizeof(*(pid_hash)));
if (!pid_hash)
panic("Could not alloc pidhash!\n");
/*
* pid_hash contains references to allocated struct pid objects and it
* must be scanned by kmemleak to avoid false positives.
*/
kmemleak_alloc(pid_hash, pidhash_size * sizeof(*(pid_hash)), 0,
GFP_KERNEL);
for (i = 0; i < pidhash_size; i++)
INIT_HLIST_HEAD(&pid_hash[i]);
}

6
mm/bootmem.c
View File

@ -12,6 +12,7 @@
#include <linux/pfn.h>
#include <linux/bootmem.h>
#include <linux/module.h>
#include <linux/kmemleak.h>
#include <asm/bug.h>
#include <asm/io.h>
@ -335,6 +336,8 @@ void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
{
unsigned long start, end;
kmemleak_free_part(__va(physaddr), size);
start = PFN_UP(physaddr);
end = PFN_DOWN(physaddr + size);
@ -354,6 +357,8 @@ void __init free_bootmem(unsigned long addr, unsigned long size)
{
unsigned long start, end;
kmemleak_free_part(__va(addr), size);
start = PFN_UP(addr);
end = PFN_DOWN(addr + size);
@ -516,6 +521,7 @@ find_block:
region = phys_to_virt(PFN_PHYS(bdata->node_min_pfn) +
start_off);
memset(region, 0, size);
kmemleak_alloc(region, size, 1, 0);
return region;
}

236
mm/kmemleak.c
View File

@ -103,10 +103,10 @@
* Kmemleak configuration and common defines.
*/
#define MAX_TRACE 16 /* stack trace length */
#define REPORTS_NR 50 /* maximum number of reported leaks */
#define MSECS_MIN_AGE 5000 /* minimum object age for reporting */
#define SECS_FIRST_SCAN 60 /* delay before the first scan */
#define SECS_SCAN_WAIT 600 /* subsequent auto scanning delay */
#define GRAY_LIST_PASSES 25 /* maximum number of gray list scans */
#define BYTES_PER_POINTER sizeof(void *)
@ -158,6 +158,8 @@ struct kmemleak_object {
#define OBJECT_REPORTED (1 << 1)
/* flag set to not scan the object */
#define OBJECT_NO_SCAN (1 << 2)
/* flag set on newly allocated objects */
#define OBJECT_NEW (1 << 3)
/* the list of all allocated objects */
static LIST_HEAD(object_list);
@ -196,9 +198,6 @@ static int kmemleak_stack_scan = 1;
/* protects the memory scanning, parameters and debug/kmemleak file access */
static DEFINE_MUTEX(scan_mutex);
/* number of leaks reported (for limitation purposes) */
static int reported_leaks;
/*
* Early object allocation/freeing logging. Kmemleak is initialized after the
* kernel allocator. However, both the kernel allocator and kmemleak may
@ -211,6 +210,7 @@ static int reported_leaks;
enum {
KMEMLEAK_ALLOC,
KMEMLEAK_FREE,
KMEMLEAK_FREE_PART,
KMEMLEAK_NOT_LEAK,
KMEMLEAK_IGNORE,
KMEMLEAK_SCAN_AREA,
@ -274,6 +274,11 @@ static int color_gray(const struct kmemleak_object *object)
return object->min_count != -1 && object->count >= object->min_count;
}
static int color_black(const struct kmemleak_object *object)
{
return object->min_count == -1;
}
/*
* Objects are considered unreferenced only if their color is white, they have
* not be deleted and have a minimum age to avoid false positives caused by
@ -451,7 +456,7 @@ static void create_object(unsigned long ptr, size_t size, int min_count,
INIT_HLIST_HEAD(&object->area_list);
spin_lock_init(&object->lock);
atomic_set(&object->use_count, 1);
object->flags = OBJECT_ALLOCATED;
object->flags = OBJECT_ALLOCATED | OBJECT_NEW;
object->pointer = ptr;
object->size = size;
object->min_count = min_count;
@ -519,27 +524,17 @@ out:
* Remove the metadata (struct kmemleak_object) for a memory block from the
* object_list and object_tree_root and decrement its use_count.
*/
static void delete_object(unsigned long ptr)
static void __delete_object(struct kmemleak_object *object)
{
unsigned long flags;
struct kmemleak_object *object;
write_lock_irqsave(&kmemleak_lock, flags);
object = lookup_object(ptr, 0);
if (!object) {
#ifdef DEBUG
kmemleak_warn("Freeing unknown object at 0x%08lx\n",
ptr);
#endif
write_unlock_irqrestore(&kmemleak_lock, flags);
return;
}
prio_tree_remove(&object_tree_root, &object->tree_node);
list_del_rcu(&object->object_list);
write_unlock_irqrestore(&kmemleak_lock, flags);
WARN_ON(!(object->flags & OBJECT_ALLOCATED));
WARN_ON(atomic_read(&object->use_count) < 1);
WARN_ON(atomic_read(&object->use_count) < 2);
/*
* Locking here also ensures that the corresponding memory block
@ -551,6 +546,64 @@ static void delete_object(unsigned long ptr)
put_object(object);
}
/*
* Look up the metadata (struct kmemleak_object) corresponding to ptr and
* delete it.
*/
static void delete_object_full(unsigned long ptr)
{
struct kmemleak_object *object;
object = find_and_get_object(ptr, 0);
if (!object) {
#ifdef DEBUG
kmemleak_warn("Freeing unknown object at 0x%08lx\n",
ptr);
#endif
return;
}
__delete_object(object);
put_object(object);
}
/*
* Look up the metadata (struct kmemleak_object) corresponding to ptr and
* delete it. If the memory block is partially freed, the function may create
* additional metadata for the remaining parts of the block.
*/
static void delete_object_part(unsigned long ptr, size_t size)
{
struct kmemleak_object *object;
unsigned long start, end;
object = find_and_get_object(ptr, 1);
if (!object) {
#ifdef DEBUG
kmemleak_warn("Partially freeing unknown object at 0x%08lx "
"(size %zu)\n", ptr, size);
#endif
return;
}
__delete_object(object);
/*
* Create one or two objects that may result from the memory block
* split. Note that partial freeing is only done by free_bootmem() and
* this happens before kmemleak_init() is called. The path below is
* only executed during early log recording in kmemleak_init(), so
* GFP_KERNEL is enough.
*/
start = object->pointer;
end = object->pointer + object->size;
if (ptr > start)
create_object(start, ptr - start, object->min_count,
GFP_KERNEL);
if (ptr + size < end)
create_object(ptr + size, end - ptr - size, object->min_count,
GFP_KERNEL);
put_object(object);
}
/*
* Make a object permanently as gray-colored so that it can no longer be
* reported as a leak. This is used in general to mark a false positive.
@ -715,12 +768,27 @@ void kmemleak_free(const void *ptr)
pr_debug("%s(0x%p)\n", __func__, ptr);
if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
delete_object((unsigned long)ptr);
delete_object_full((unsigned long)ptr);
else if (atomic_read(&kmemleak_early_log))
log_early(KMEMLEAK_FREE, ptr, 0, 0, 0, 0);
}
EXPORT_SYMBOL_GPL(kmemleak_free);
/*
* Partial memory freeing function callback. This function is usually called
* from bootmem allocator when (part of) a memory block is freed.
*/
void kmemleak_free_part(const void *ptr, size_t size)
{
pr_debug("%s(0x%p)\n", __func__, ptr);
if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr))
delete_object_part((unsigned long)ptr, size);
else if (atomic_read(&kmemleak_early_log))
log_early(KMEMLEAK_FREE_PART, ptr, size, 0, 0, 0);
}
EXPORT_SYMBOL_GPL(kmemleak_free_part);
/*
* Mark an already allocated memory block as a false positive. This will cause
* the block to no longer be reported as leak and always be scanned.
@ -807,7 +875,7 @@ static int scan_should_stop(void)
* found to the gray list.
*/
static void scan_block(void *_start, void *_end,
struct kmemleak_object *scanned)
struct kmemleak_object *scanned, int allow_resched)
{
unsigned long *ptr;
unsigned long *start = PTR_ALIGN(_start, BYTES_PER_POINTER);
@ -818,6 +886,8 @@ static void scan_block(void *_start, void *_end,
unsigned long pointer = *ptr;
struct kmemleak_object *object;
if (allow_resched)
cond_resched();
if (scan_should_stop())
break;
@ -881,12 +951,12 @@ static void scan_object(struct kmemleak_object *object)
goto out;
if (hlist_empty(&object->area_list))
scan_block((void *)object->pointer,
(void *)(object->pointer + object->size), object);
(void *)(object->pointer + object->size), object, 0);
else
hlist_for_each_entry(area, elem, &object->area_list, node)
scan_block((void *)(object->pointer + area->offset),
(void *)(object->pointer + area->offset
+ area->length), object);
+ area->length), object, 0);
out:
spin_unlock_irqrestore(&object->lock, flags);
}
@ -903,6 +973,7 @@ static void kmemleak_scan(void)
struct task_struct *task;
int i;
int new_leaks = 0;
int gray_list_pass = 0;
jiffies_last_scan = jiffies;
@ -923,6 +994,7 @@ static void kmemleak_scan(void)
#endif
/* reset the reference count (whiten the object) */
object->count = 0;
object->flags &= ~OBJECT_NEW;
if (color_gray(object) && get_object(object))
list_add_tail(&object->gray_list, &gray_list);
@ -931,14 +1003,14 @@ static void kmemleak_scan(void)
rcu_read_unlock();
/* data/bss scanning */
scan_block(_sdata, _edata, NULL);
scan_block(__bss_start, __bss_stop, NULL);
scan_block(_sdata, _edata, NULL, 1);
scan_block(__bss_start, __bss_stop, NULL, 1);
#ifdef CONFIG_SMP
/* per-cpu sections scanning */
for_each_possible_cpu(i)
scan_block(__per_cpu_start + per_cpu_offset(i),
__per_cpu_end + per_cpu_offset(i), NULL);
__per_cpu_end + per_cpu_offset(i), NULL, 1);
#endif
/*
@ -960,7 +1032,7 @@ static void kmemleak_scan(void)
/* only scan if page is in use */
if (page_count(page) == 0)
continue;
scan_block(page, page + 1, NULL);
scan_block(page, page + 1, NULL, 1);
}
}
@ -972,7 +1044,8 @@ static void kmemleak_scan(void)
read_lock(&tasklist_lock);
for_each_process(task)
scan_block(task_stack_page(task),
task_stack_page(task) + THREAD_SIZE, NULL);
task_stack_page(task) + THREAD_SIZE,
NULL, 0);
read_unlock(&tasklist_lock);
}
@ -984,6 +1057,7 @@ static void kmemleak_scan(void)
* kmemleak objects cannot be freed from outside the loop because their
* use_count was increased.
*/
repeat:
object = list_entry(gray_list.next, typeof(*object), gray_list);
while (&object->gray_list != &gray_list) {
cond_resched();
@ -1001,12 +1075,38 @@ static void kmemleak_scan(void)
object = tmp;
}
if (scan_should_stop() || ++gray_list_pass >= GRAY_LIST_PASSES)
goto scan_end;
/*
* Check for new objects allocated during this scanning and add them
* to the gray list.
*/
rcu_read_lock();
list_for_each_entry_rcu(object, &object_list, object_list) {
spin_lock_irqsave(&object->lock, flags);
if ((object->flags & OBJECT_NEW) && !color_black(object) &&
get_object(object)) {
object->flags &= ~OBJECT_NEW;
list_add_tail(&object->gray_list, &gray_list);
}
spin_unlock_irqrestore(&object->lock, flags);
}
rcu_read_unlock();
if (!list_empty(&gray_list))
goto repeat;
scan_end:
WARN_ON(!list_empty(&gray_list));
/*
* If scanning was stopped do not report any new unreferenced objects.
* If scanning was stopped or new objects were being allocated at a
* higher rate than gray list scanning, do not report any new
* unreferenced objects.
*/
if (scan_should_stop())
if (scan_should_stop() || gray_list_pass >= GRAY_LIST_PASSES)
return;
/*
@ -1039,6 +1139,7 @@ static int kmemleak_scan_thread(void *arg)
static int first_run = 1;
pr_info("Automatic memory scanning thread started\n");
set_user_nice(current, 10);
/*
* Wait before the first scan to allow the system to fully initialize.
@ -1101,11 +1202,11 @@ static void *kmemleak_seq_start(struct seq_file *seq, loff_t *pos)
{
struct kmemleak_object *object;
loff_t n = *pos;
int err;
if (!n)
reported_leaks = 0;
if (reported_leaks >= REPORTS_NR)
return NULL;
err = mutex_lock_interruptible(&scan_mutex);
if (err < 0)
return ERR_PTR(err);
rcu_read_lock();
list_for_each_entry_rcu(object, &object_list, object_list) {
@ -1131,8 +1232,6 @@ static void *kmemleak_seq_next(struct seq_file *seq, void *v, loff_t *pos)
struct list_head *n = &prev_obj->object_list;
++(*pos);
if (reported_leaks >= REPORTS_NR)
goto out;
rcu_read_lock();
list_for_each_continue_rcu(n, &object_list) {
@ -1141,7 +1240,7 @@ static void *kmemleak_seq_next(struct seq_file *seq, void *v, loff_t *pos)
break;
}
rcu_read_unlock();
out:
put_object(prev_obj);
return next_obj;
}
@ -1151,8 +1250,15 @@ out:
*/
static void kmemleak_seq_stop(struct seq_file *seq, void *v)
{
if (v)
put_object(v);
if (!IS_ERR(v)) {
/*
* kmemleak_seq_start may return ERR_PTR if the scan_mutex
* waiting was interrupted, so only release it if !IS_ERR.
*/
mutex_unlock(&scan_mutex);
if (v)
put_object(v);
}
}
/*
@ -1164,10 +1270,8 @@ static int kmemleak_seq_show(struct seq_file *seq, void *v)
unsigned long flags;
spin_lock_irqsave(&object->lock, flags);
if ((object->flags & OBJECT_REPORTED) && unreferenced_object(object)) {
if ((object->flags & OBJECT_REPORTED) && unreferenced_object(object))
print_unreferenced(seq, object);
reported_leaks++;
}
spin_unlock_irqrestore(&object->lock, flags);
return 0;
}
@ -1181,36 +1285,15 @@ static const struct seq_operations kmemleak_seq_ops = {
static int kmemleak_open(struct inode *inode, struct file *file)
{
int ret = 0;
if (!atomic_read(&kmemleak_enabled))
return -EBUSY;
ret = mutex_lock_interruptible(&scan_mutex);
if (ret < 0)
goto out;
if (file->f_mode & FMODE_READ) {
ret = seq_open(file, &kmemleak_seq_ops);
if (ret < 0)
goto scan_unlock;
}
return ret;
scan_unlock:
mutex_unlock(&scan_mutex);
out:
return ret;
return seq_open(file, &kmemleak_seq_ops);
}
static int kmemleak_release(struct inode *inode, struct file *file)
{
int ret = 0;
if (file->f_mode & FMODE_READ)
seq_release(inode, file);
mutex_unlock(&scan_mutex);
return ret;
return seq_release(inode, file);
}
/*
@ -1230,15 +1313,17 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
{
char buf[64];
int buf_size;
if (!atomic_read(&kmemleak_enabled))
return -EBUSY;
int ret;
buf_size = min(size, (sizeof(buf) - 1));
if (strncpy_from_user(buf, user_buf, buf_size) < 0)
return -EFAULT;
buf[buf_size] = 0;
ret = mutex_lock_interruptible(&scan_mutex);
if (ret < 0)
return ret;
if (strncmp(buf, "off", 3) == 0)
kmemleak_disable();
else if (strncmp(buf, "stack=on", 8) == 0)
@ -1251,11 +1336,10 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
stop_scan_thread();
else if (strncmp(buf, "scan=", 5) == 0) {
unsigned long secs;
int err;
err = strict_strtoul(buf + 5, 0, &secs);
if (err < 0)
return err;
ret = strict_strtoul(buf + 5, 0, &secs);
if (ret < 0)
goto out;
stop_scan_thread();
if (secs) {
jiffies_scan_wait = msecs_to_jiffies(secs * 1000);
@ -1264,7 +1348,12 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
} else if (strncmp(buf, "scan", 4) == 0)
kmemleak_scan();
else
return -EINVAL;
ret = -EINVAL;
out:
mutex_unlock(&scan_mutex);
if (ret < 0)
return ret;
/* ignore the rest of the buffer, only one command at a time */
*ppos += size;
@ -1293,7 +1382,7 @@ static int kmemleak_cleanup_thread(void *arg)
rcu_read_lock();
list_for_each_entry_rcu(object, &object_list, object_list)
delete_object(object->pointer);
delete_object_full(object->pointer);
rcu_read_unlock();
mutex_unlock(&scan_mutex);
@ -1388,6 +1477,9 @@ void __init kmemleak_init(void)
case KMEMLEAK_FREE:
kmemleak_free(log->ptr);
break;
case KMEMLEAK_FREE_PART:
kmemleak_free_part(log->ptr, log->size);
break;
case KMEMLEAK_NOT_LEAK:
kmemleak_not_leak(log->ptr);
break;

14
mm/page_alloc.c
View File

@ -4745,8 +4745,10 @@ void *__init alloc_large_system_hash(const char *tablename,
* some pages at the end of hash table which
* alloc_pages_exact() automatically does
*/
if (get_order(size) < MAX_ORDER)
if (get_order(size) < MAX_ORDER) {
table = alloc_pages_exact(size, GFP_ATOMIC);
kmemleak_alloc(table, size, 1, GFP_ATOMIC);
}
}
} while (!table && size > PAGE_SIZE && --log2qty);
@ -4764,16 +4766,6 @@ void *__init alloc_large_system_hash(const char *tablename,
if (_hash_mask)
*_hash_mask = (1 << log2qty) - 1;
/*
* If hashdist is set, the table allocation is done with __vmalloc()
* which invokes the kmemleak_alloc() callback. This function may also
* be called before the slab and kmemleak are initialised when
* kmemleak simply buffers the request to be executed later
* (GFP_ATOMIC flag ignored in this case).
*/
if (!hashdist)
kmemleak_alloc(table, size, 1, GFP_ATOMIC);
return table;
}

10
mm/slub.c
View File

@ -21,7 +21,6 @@
#include <linux/kmemcheck.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
#include <linux/kmemleak.h>
#include <linux/mempolicy.h>
#include <linux/ctype.h>
#include <linux/debugobjects.h>
@ -2835,13 +2834,15 @@ EXPORT_SYMBOL(__kmalloc);
static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
{
struct page *page;
void *ptr = NULL;
flags |= __GFP_COMP | __GFP_NOTRACK;
page = alloc_pages_node(node, flags, get_order(size));
if (page)
return page_address(page);
else
return NULL;
ptr = page_address(page);
kmemleak_alloc(ptr, size, 1, flags);
return ptr;
}
#ifdef CONFIG_NUMA
@ -2926,6 +2927,7 @@ void kfree(const void *x)
page = virt_to_head_page(x);
if (unlikely(!PageSlab(page))) {
BUG_ON(!PageCompound(page));
kmemleak_free(x);
put_page(page);
return;
}