diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-11 17:15:57 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-11 17:15:57 -0400 |
commit | 512626a04e72aca60effe111fa0333ed0b195d21 (patch) | |
tree | c22e23b0dcc2dd2ff5a9a96a007de6799e9223de /mm | |
parent | 8a1ca8cedd108c8e76a6ab34079d0bbb4f244799 (diff) | |
parent | 3aa27bbe7a6536d1ec859d3a97caf3319b5081b7 (diff) |
Merge branch 'for-linus' of git://linux-arm.org/linux-2.6
* 'for-linus' of git://linux-arm.org/linux-2.6:
kmemleak: Add the corresponding MAINTAINERS entry
kmemleak: Simple testing module for kmemleak
kmemleak: Enable the building of the memory leak detector
kmemleak: Remove some of the kmemleak false positives
kmemleak: Add modules support
kmemleak: Add kmemleak_alloc callback from alloc_large_system_hash
kmemleak: Add the vmalloc memory allocation/freeing hooks
kmemleak: Add the slub memory allocation/freeing hooks
kmemleak: Add the slob memory allocation/freeing hooks
kmemleak: Add the slab memory allocation/freeing hooks
kmemleak: Add documentation on the memory leak detector
kmemleak: Add the base support
Manual conflict resolution (with the slab/earlyboot changes) in:
drivers/char/vt.c
init/main.c
mm/slab.c
Diffstat (limited to 'mm')
-rw-r--r-- | mm/Makefile | 2 | ||||
-rw-r--r-- | mm/kmemleak-test.c | 111 | ||||
-rw-r--r-- | mm/kmemleak.c | 1498 | ||||
-rw-r--r-- | mm/page_alloc.c | 11 | ||||
-rw-r--r-- | mm/slab.c | 32 | ||||
-rw-r--r-- | mm/slob.c | 7 | ||||
-rw-r--r-- | mm/slub.c | 5 | ||||
-rw-r--r-- | mm/vmalloc.c | 30 |
8 files changed, 1690 insertions, 6 deletions
diff --git a/mm/Makefile b/mm/Makefile index ec73c68b6015..e89acb090b4d 100644 --- a/mm/Makefile +++ b/mm/Makefile | |||
@@ -38,3 +38,5 @@ obj-$(CONFIG_SMP) += allocpercpu.o | |||
38 | endif | 38 | endif |
39 | obj-$(CONFIG_QUICKLIST) += quicklist.o | 39 | obj-$(CONFIG_QUICKLIST) += quicklist.o |
40 | obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o | 40 | obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o |
41 | obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o | ||
42 | obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o | ||
diff --git a/mm/kmemleak-test.c b/mm/kmemleak-test.c new file mode 100644 index 000000000000..d5292fc6f523 --- /dev/null +++ b/mm/kmemleak-test.c | |||
@@ -0,0 +1,111 @@ | |||
1 | /* | ||
2 | * mm/kmemleak-test.c | ||
3 | * | ||
4 | * Copyright (C) 2008 ARM Limited | ||
5 | * Written by Catalin Marinas <catalin.marinas@arm.com> | ||
6 | * | ||
7 | * This program is free software; you can redistribute it and/or modify | ||
8 | * it under the terms of the GNU General Public License version 2 as | ||
9 | * published by the Free Software Foundation. | ||
10 | * | ||
11 | * This program is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
14 | * GNU General Public License for more details. | ||
15 | * | ||
16 | * You should have received a copy of the GNU General Public License | ||
17 | * along with this program; if not, write to the Free Software | ||
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
19 | */ | ||
20 | |||
21 | #include <linux/init.h> | ||
22 | #include <linux/kernel.h> | ||
23 | #include <linux/module.h> | ||
24 | #include <linux/slab.h> | ||
25 | #include <linux/vmalloc.h> | ||
26 | #include <linux/list.h> | ||
27 | #include <linux/percpu.h> | ||
28 | #include <linux/fdtable.h> | ||
29 | |||
30 | #include <linux/kmemleak.h> | ||
31 | |||
32 | struct test_node { | ||
33 | long header[25]; | ||
34 | struct list_head list; | ||
35 | long footer[25]; | ||
36 | }; | ||
37 | |||
38 | static LIST_HEAD(test_list); | ||
39 | static DEFINE_PER_CPU(void *, test_pointer); | ||
40 | |||
41 | /* | ||
42 | * Some very simple testing. This function needs to be extended for | ||
43 | * proper testing. | ||
44 | */ | ||
45 | static int __init kmemleak_test_init(void) | ||
46 | { | ||
47 | struct test_node *elem; | ||
48 | int i; | ||
49 | |||
50 | printk(KERN_INFO "Kmemleak testing\n"); | ||
51 | |||
52 | /* make some orphan objects */ | ||
53 | pr_info("kmemleak: kmalloc(32) = %p\n", kmalloc(32, GFP_KERNEL)); | ||
54 | pr_info("kmemleak: kmalloc(32) = %p\n", kmalloc(32, GFP_KERNEL)); | ||
55 | pr_info("kmemleak: kmalloc(1024) = %p\n", kmalloc(1024, GFP_KERNEL)); | ||
56 | pr_info("kmemleak: kmalloc(1024) = %p\n", kmalloc(1024, GFP_KERNEL)); | ||
57 | pr_info("kmemleak: kmalloc(2048) = %p\n", kmalloc(2048, GFP_KERNEL)); | ||
58 | pr_info("kmemleak: kmalloc(2048) = %p\n", kmalloc(2048, GFP_KERNEL)); | ||
59 | pr_info("kmemleak: kmalloc(4096) = %p\n", kmalloc(4096, GFP_KERNEL)); | ||
60 | pr_info("kmemleak: kmalloc(4096) = %p\n", kmalloc(4096, GFP_KERNEL)); | ||
61 | #ifndef CONFIG_MODULES | ||
62 | pr_info("kmemleak: kmem_cache_alloc(files_cachep) = %p\n", | ||
63 | kmem_cache_alloc(files_cachep, GFP_KERNEL)); | ||
64 | pr_info("kmemleak: kmem_cache_alloc(files_cachep) = %p\n", | ||
65 | kmem_cache_alloc(files_cachep, GFP_KERNEL)); | ||
66 | #endif | ||
67 | pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64)); | ||
68 | pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64)); | ||
69 | pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64)); | ||
70 | pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64)); | ||
71 | pr_info("kmemleak: vmalloc(64) = %p\n", vmalloc(64)); | ||
72 | |||
73 | /* | ||
74 | * Add elements to a list. They should only appear as orphan | ||
75 | * after the module is removed. | ||
76 | */ | ||
77 | for (i = 0; i < 10; i++) { | ||
78 | elem = kmalloc(sizeof(*elem), GFP_KERNEL); | ||
79 | pr_info("kmemleak: kmalloc(sizeof(*elem)) = %p\n", elem); | ||
80 | if (!elem) | ||
81 | return -ENOMEM; | ||
82 | memset(elem, 0, sizeof(*elem)); | ||
83 | INIT_LIST_HEAD(&elem->list); | ||
84 | |||
85 | list_add_tail(&elem->list, &test_list); | ||
86 | } | ||
87 | |||
88 | for_each_possible_cpu(i) { | ||
89 | per_cpu(test_pointer, i) = kmalloc(129, GFP_KERNEL); | ||
90 | pr_info("kmemleak: kmalloc(129) = %p\n", | ||
91 | per_cpu(test_pointer, i)); | ||
92 | } | ||
93 | |||
94 | return 0; | ||
95 | } | ||
96 | module_init(kmemleak_test_init); | ||
97 | |||
98 | static void __exit kmemleak_test_exit(void) | ||
99 | { | ||
100 | struct test_node *elem, *tmp; | ||
101 | |||
102 | /* | ||
103 | * Remove the list elements without actually freeing the | ||
104 | * memory. | ||
105 | */ | ||
106 | list_for_each_entry_safe(elem, tmp, &test_list, list) | ||
107 | list_del(&elem->list); | ||
108 | } | ||
109 | module_exit(kmemleak_test_exit); | ||
110 | |||
111 | MODULE_LICENSE("GPL"); | ||
diff --git a/mm/kmemleak.c b/mm/kmemleak.c new file mode 100644 index 000000000000..58ec86c9e58a --- /dev/null +++ b/mm/kmemleak.c | |||
@@ -0,0 +1,1498 @@ | |||
1 | /* | ||
2 | * mm/kmemleak.c | ||
3 | * | ||
4 | * Copyright (C) 2008 ARM Limited | ||
5 | * Written by Catalin Marinas <catalin.marinas@arm.com> | ||
6 | * | ||
7 | * This program is free software; you can redistribute it and/or modify | ||
8 | * it under the terms of the GNU General Public License version 2 as | ||
9 | * published by the Free Software Foundation. | ||
10 | * | ||
11 | * This program is distributed in the hope that it will be useful, | ||
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
14 | * GNU General Public License for more details. | ||
15 | * | ||
16 | * You should have received a copy of the GNU General Public License | ||
17 | * along with this program; if not, write to the Free Software | ||
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
19 | * | ||
20 | * | ||
21 | * For more information on the algorithm and kmemleak usage, please see | ||
22 | * Documentation/kmemleak.txt. | ||
23 | * | ||
24 | * Notes on locking | ||
25 | * ---------------- | ||
26 | * | ||
27 | * The following locks and mutexes are used by kmemleak: | ||
28 | * | ||
29 | * - kmemleak_lock (rwlock): protects the object_list modifications and | ||
30 | * accesses to the object_tree_root. The object_list is the main list | ||
31 | * holding the metadata (struct kmemleak_object) for the allocated memory | ||
32 | * blocks. The object_tree_root is a priority search tree used to look-up | ||
33 | * metadata based on a pointer to the corresponding memory block. The | ||
34 | * kmemleak_object structures are added to the object_list and | ||
35 | * object_tree_root in the create_object() function called from the | ||
36 | * kmemleak_alloc() callback and removed in delete_object() called from the | ||
37 | * kmemleak_free() callback | ||
38 | * - kmemleak_object.lock (spinlock): protects a kmemleak_object. Accesses to | ||
39 | * the metadata (e.g. count) are protected by this lock. Note that some | ||
40 | * members of this structure may be protected by other means (atomic or | ||
41 | * kmemleak_lock). This lock is also held when scanning the corresponding | ||
42 | * memory block to avoid the kernel freeing it via the kmemleak_free() | ||
43 | * callback. This is less heavyweight than holding a global lock like | ||
44 | * kmemleak_lock during scanning | ||
45 | * - scan_mutex (mutex): ensures that only one thread may scan the memory for | ||
46 | * unreferenced objects at a time. The gray_list contains the objects which | ||
47 | * are already referenced or marked as false positives and need to be | ||
48 | * scanned. This list is only modified during a scanning episode when the | ||
49 | * scan_mutex is held. At the end of a scan, the gray_list is always empty. | ||
50 | * Note that the kmemleak_object.use_count is incremented when an object is | ||
51 | * added to the gray_list and therefore cannot be freed | ||
52 | * - kmemleak_mutex (mutex): prevents multiple users of the "kmemleak" debugfs | ||
53 | * file together with modifications to the memory scanning parameters | ||
54 | * including the scan_thread pointer | ||
55 | * | ||
56 | * The kmemleak_object structures have a use_count incremented or decremented | ||
57 | * using the get_object()/put_object() functions. When the use_count becomes | ||
58 | * 0, this count can no longer be incremented and put_object() schedules the | ||
59 | * kmemleak_object freeing via an RCU callback. All calls to the get_object() | ||
60 | * function must be protected by rcu_read_lock() to avoid accessing a freed | ||
61 | * structure. | ||
62 | */ | ||
63 | |||
64 | #include <linux/init.h> | ||
65 | #include <linux/kernel.h> | ||
66 | #include <linux/list.h> | ||
67 | #include <linux/sched.h> | ||
68 | #include <linux/jiffies.h> | ||
69 | #include <linux/delay.h> | ||
70 | #include <linux/module.h> | ||
71 | #include <linux/kthread.h> | ||
72 | #include <linux/prio_tree.h> | ||
73 | #include <linux/gfp.h> | ||
74 | #include <linux/fs.h> | ||
75 | #include <linux/debugfs.h> | ||
76 | #include <linux/seq_file.h> | ||
77 | #include <linux/cpumask.h> | ||
78 | #include <linux/spinlock.h> | ||
79 | #include <linux/mutex.h> | ||
80 | #include <linux/rcupdate.h> | ||
81 | #include <linux/stacktrace.h> | ||
82 | #include <linux/cache.h> | ||
83 | #include <linux/percpu.h> | ||
84 | #include <linux/hardirq.h> | ||
85 | #include <linux/mmzone.h> | ||
86 | #include <linux/slab.h> | ||
87 | #include <linux/thread_info.h> | ||
88 | #include <linux/err.h> | ||
89 | #include <linux/uaccess.h> | ||
90 | #include <linux/string.h> | ||
91 | #include <linux/nodemask.h> | ||
92 | #include <linux/mm.h> | ||
93 | |||
94 | #include <asm/sections.h> | ||
95 | #include <asm/processor.h> | ||
96 | #include <asm/atomic.h> | ||
97 | |||
98 | #include <linux/kmemleak.h> | ||
99 | |||
100 | /* | ||
101 | * Kmemleak configuration and common defines. | ||
102 | */ | ||
103 | #define MAX_TRACE 16 /* stack trace length */ | ||
104 | #define REPORTS_NR 50 /* maximum number of reported leaks */ | ||
105 | #define MSECS_MIN_AGE 5000 /* minimum object age for reporting */ | ||
106 | #define MSECS_SCAN_YIELD 10 /* CPU yielding period */ | ||
107 | #define SECS_FIRST_SCAN 60 /* delay before the first scan */ | ||
108 | #define SECS_SCAN_WAIT 600 /* subsequent auto scanning delay */ | ||
109 | |||
110 | #define BYTES_PER_POINTER sizeof(void *) | ||
111 | |||
112 | /* scanning area inside a memory block */ | ||
113 | struct kmemleak_scan_area { | ||
114 | struct hlist_node node; | ||
115 | unsigned long offset; | ||
116 | size_t length; | ||
117 | }; | ||
118 | |||
119 | /* | ||
120 | * Structure holding the metadata for each allocated memory block. | ||
121 | * Modifications to such objects should be made while holding the | ||
122 | * object->lock. Insertions or deletions from object_list, gray_list or | ||
123 | * tree_node are already protected by the corresponding locks or mutex (see | ||
124 | * the notes on locking above). These objects are reference-counted | ||
125 | * (use_count) and freed using the RCU mechanism. | ||
126 | */ | ||
127 | struct kmemleak_object { | ||
128 | spinlock_t lock; | ||
129 | unsigned long flags; /* object status flags */ | ||
130 | struct list_head object_list; | ||
131 | struct list_head gray_list; | ||
132 | struct prio_tree_node tree_node; | ||
133 | struct rcu_head rcu; /* object_list lockless traversal */ | ||
134 | /* object usage count; object freed when use_count == 0 */ | ||
135 | atomic_t use_count; | ||
136 | unsigned long pointer; | ||
137 | size_t size; | ||
138 | /* minimum number of a pointers found before it is considered leak */ | ||
139 | int min_count; | ||
140 | /* the total number of pointers found pointing to this object */ | ||
141 | int count; | ||
142 | /* memory ranges to be scanned inside an object (empty for all) */ | ||
143 | struct hlist_head area_list; | ||
144 | unsigned long trace[MAX_TRACE]; | ||
145 | unsigned int trace_len; | ||
146 | unsigned long jiffies; /* creation timestamp */ | ||
147 | pid_t pid; /* pid of the current task */ | ||
148 | char comm[TASK_COMM_LEN]; /* executable name */ | ||
149 | }; | ||
150 | |||
151 | /* flag representing the memory block allocation status */ | ||
152 | #define OBJECT_ALLOCATED (1 << 0) | ||
153 | /* flag set after the first reporting of an unreference object */ | ||
154 | #define OBJECT_REPORTED (1 << 1) | ||
155 | /* flag set to not scan the object */ | ||
156 | #define OBJECT_NO_SCAN (1 << 2) | ||
157 | |||
158 | /* the list of all allocated objects */ | ||
159 | static LIST_HEAD(object_list); | ||
160 | /* the list of gray-colored objects (see color_gray comment below) */ | ||
161 | static LIST_HEAD(gray_list); | ||
162 | /* prio search tree for object boundaries */ | ||
163 | static struct prio_tree_root object_tree_root; | ||
164 | /* rw_lock protecting the access to object_list and prio_tree_root */ | ||
165 | static DEFINE_RWLOCK(kmemleak_lock); | ||
166 | |||
167 | /* allocation caches for kmemleak internal data */ | ||
168 | static struct kmem_cache *object_cache; | ||
169 | static struct kmem_cache *scan_area_cache; | ||
170 | |||
171 | /* set if tracing memory operations is enabled */ | ||
172 | static atomic_t kmemleak_enabled = ATOMIC_INIT(0); | ||
173 | /* set in the late_initcall if there were no errors */ | ||
174 | static atomic_t kmemleak_initialized = ATOMIC_INIT(0); | ||
175 | /* enables or disables early logging of the memory operations */ | ||
176 | static atomic_t kmemleak_early_log = ATOMIC_INIT(1); | ||
177 | /* set if a fata kmemleak error has occurred */ | ||
178 | static atomic_t kmemleak_error = ATOMIC_INIT(0); | ||
179 | |||
180 | /* minimum and maximum address that may be valid pointers */ | ||
181 | static unsigned long min_addr = ULONG_MAX; | ||
182 | static unsigned long max_addr; | ||
183 | |||
184 | /* used for yielding the CPU to other tasks during scanning */ | ||
185 | static unsigned long next_scan_yield; | ||
186 | static struct task_struct *scan_thread; | ||
187 | static unsigned long jiffies_scan_yield; | ||
188 | static unsigned long jiffies_min_age; | ||
189 | /* delay between automatic memory scannings */ | ||
190 | static signed long jiffies_scan_wait; | ||
191 | /* enables or disables the task stacks scanning */ | ||
192 | static int kmemleak_stack_scan; | ||
193 | /* mutex protecting the memory scanning */ | ||
194 | static DEFINE_MUTEX(scan_mutex); | ||
195 | /* mutex protecting the access to the /sys/kernel/debug/kmemleak file */ | ||
196 | static DEFINE_MUTEX(kmemleak_mutex); | ||
197 | |||
198 | /* number of leaks reported (for limitation purposes) */ | ||
199 | static int reported_leaks; | ||
200 | |||
201 | /* | ||
202 | * Early object allocation/freeing logging. Kkmemleak is initialized after the | ||
203 | * kernel allocator. However, both the kernel allocator and kmemleak may | ||
204 | * allocate memory blocks which need to be tracked. Kkmemleak defines an | ||
205 | * arbitrary buffer to hold the allocation/freeing information before it is | ||
206 | * fully initialized. | ||
207 | */ | ||
208 | |||
209 | /* kmemleak operation type for early logging */ | ||
210 | enum { | ||
211 | KMEMLEAK_ALLOC, | ||
212 | KMEMLEAK_FREE, | ||
213 | KMEMLEAK_NOT_LEAK, | ||
214 | KMEMLEAK_IGNORE, | ||
215 | KMEMLEAK_SCAN_AREA, | ||
216 | KMEMLEAK_NO_SCAN | ||
217 | }; | ||
218 | |||
219 | /* | ||
220 | * Structure holding the information passed to kmemleak callbacks during the | ||
221 | * early logging. | ||
222 | */ | ||
223 | struct early_log { | ||
224 | int op_type; /* kmemleak operation type */ | ||
225 | const void *ptr; /* allocated/freed memory block */ | ||
226 | size_t size; /* memory block size */ | ||
227 | int min_count; /* minimum reference count */ | ||
228 | unsigned long offset; /* scan area offset */ | ||
229 | size_t length; /* scan area length */ | ||
230 | }; | ||
231 | |||
232 | /* early logging buffer and current position */ | ||
233 | static struct early_log early_log[200]; | ||
234 | static int crt_early_log; | ||
235 | |||
236 | static void kmemleak_disable(void); | ||
237 | |||
238 | /* | ||
239 | * Print a warning and dump the stack trace. | ||
240 | */ | ||
241 | #define kmemleak_warn(x...) do { \ | ||
242 | pr_warning(x); \ | ||
243 | dump_stack(); \ | ||
244 | } while (0) | ||
245 | |||
246 | /* | ||
247 | * Macro invoked when a serious kmemleak condition occured and cannot be | ||
248 | * recovered from. Kkmemleak will be disabled and further allocation/freeing | ||
249 | * tracing no longer available. | ||
250 | */ | ||
251 | #define kmemleak_panic(x...) do { \ | ||
252 | kmemleak_warn(x); \ | ||
253 | kmemleak_disable(); \ | ||
254 | } while (0) | ||
255 | |||
256 | /* | ||
257 | * Object colors, encoded with count and min_count: | ||
258 | * - white - orphan object, not enough references to it (count < min_count) | ||
259 | * - gray - not orphan, not marked as false positive (min_count == 0) or | ||
260 | * sufficient references to it (count >= min_count) | ||
261 | * - black - ignore, it doesn't contain references (e.g. text section) | ||
262 | * (min_count == -1). No function defined for this color. | ||
263 | * Newly created objects don't have any color assigned (object->count == -1) | ||
264 | * before the next memory scan when they become white. | ||
265 | */ | ||
266 | static int color_white(const struct kmemleak_object *object) | ||
267 | { | ||
268 | return object->count != -1 && object->count < object->min_count; | ||
269 | } | ||
270 | |||
271 | static int color_gray(const struct kmemleak_object *object) | ||
272 | { | ||
273 | return object->min_count != -1 && object->count >= object->min_count; | ||
274 | } | ||
275 | |||
276 | /* | ||
277 | * Objects are considered referenced if their color is gray and they have not | ||
278 | * been deleted. | ||
279 | */ | ||
280 | static int referenced_object(struct kmemleak_object *object) | ||
281 | { | ||
282 | return (object->flags & OBJECT_ALLOCATED) && color_gray(object); | ||
283 | } | ||
284 | |||
285 | /* | ||
286 | * Objects are considered unreferenced only if their color is white, they have | ||
287 | * not be deleted and have a minimum age to avoid false positives caused by | ||
288 | * pointers temporarily stored in CPU registers. | ||
289 | */ | ||
290 | static int unreferenced_object(struct kmemleak_object *object) | ||
291 | { | ||
292 | return (object->flags & OBJECT_ALLOCATED) && color_white(object) && | ||
293 | time_is_before_eq_jiffies(object->jiffies + jiffies_min_age); | ||
294 | } | ||
295 | |||
296 | /* | ||
297 | * Printing of the (un)referenced objects information, either to the seq file | ||
298 | * or to the kernel log. The print_referenced/print_unreferenced functions | ||
299 | * must be called with the object->lock held. | ||
300 | */ | ||
301 | #define print_helper(seq, x...) do { \ | ||
302 | struct seq_file *s = (seq); \ | ||
303 | if (s) \ | ||
304 | seq_printf(s, x); \ | ||
305 | else \ | ||
306 | pr_info(x); \ | ||
307 | } while (0) | ||
308 | |||
309 | static void print_referenced(struct kmemleak_object *object) | ||
310 | { | ||
311 | pr_info("kmemleak: referenced object 0x%08lx (size %zu)\n", | ||
312 | object->pointer, object->size); | ||
313 | } | ||
314 | |||
315 | static void print_unreferenced(struct seq_file *seq, | ||
316 | struct kmemleak_object *object) | ||
317 | { | ||
318 | int i; | ||
319 | |||
320 | print_helper(seq, "kmemleak: unreferenced object 0x%08lx (size %zu):\n", | ||
321 | object->pointer, object->size); | ||
322 | print_helper(seq, " comm \"%s\", pid %d, jiffies %lu\n", | ||
323 | object->comm, object->pid, object->jiffies); | ||
324 | print_helper(seq, " backtrace:\n"); | ||
325 | |||
326 | for (i = 0; i < object->trace_len; i++) { | ||
327 | void *ptr = (void *)object->trace[i]; | ||
328 | print_helper(seq, " [<%p>] %pS\n", ptr, ptr); | ||
329 | } | ||
330 | } | ||
331 | |||
332 | /* | ||
333 | * Print the kmemleak_object information. This function is used mainly for | ||
334 | * debugging special cases when kmemleak operations. It must be called with | ||
335 | * the object->lock held. | ||
336 | */ | ||
337 | static void dump_object_info(struct kmemleak_object *object) | ||
338 | { | ||
339 | struct stack_trace trace; | ||
340 | |||
341 | trace.nr_entries = object->trace_len; | ||
342 | trace.entries = object->trace; | ||
343 | |||
344 | pr_notice("kmemleak: Object 0x%08lx (size %zu):\n", | ||
345 | object->tree_node.start, object->size); | ||
346 | pr_notice(" comm \"%s\", pid %d, jiffies %lu\n", | ||
347 | object->comm, object->pid, object->jiffies); | ||
348 | pr_notice(" min_count = %d\n", object->min_count); | ||
349 | pr_notice(" count = %d\n", object->count); | ||
350 | pr_notice(" backtrace:\n"); | ||
351 | print_stack_trace(&trace, 4); | ||
352 | } | ||
353 | |||
354 | /* | ||
355 | * Look-up a memory block metadata (kmemleak_object) in the priority search | ||
356 | * tree based on a pointer value. If alias is 0, only values pointing to the | ||
357 | * beginning of the memory block are allowed. The kmemleak_lock must be held | ||
358 | * when calling this function. | ||
359 | */ | ||
360 | static struct kmemleak_object *lookup_object(unsigned long ptr, int alias) | ||
361 | { | ||
362 | struct prio_tree_node *node; | ||
363 | struct prio_tree_iter iter; | ||
364 | struct kmemleak_object *object; | ||
365 | |||
366 | prio_tree_iter_init(&iter, &object_tree_root, ptr, ptr); | ||
367 | node = prio_tree_next(&iter); | ||
368 | if (node) { | ||
369 | object = prio_tree_entry(node, struct kmemleak_object, | ||
370 | tree_node); | ||
371 | if (!alias && object->pointer != ptr) { | ||
372 | kmemleak_warn("kmemleak: Found object by alias"); | ||
373 | object = NULL; | ||
374 | } | ||
375 | } else | ||
376 | object = NULL; | ||
377 | |||
378 | return object; | ||
379 | } | ||
380 | |||
381 | /* | ||
382 | * Increment the object use_count. Return 1 if successful or 0 otherwise. Note | ||
383 | * that once an object's use_count reached 0, the RCU freeing was already | ||
384 | * registered and the object should no longer be used. This function must be | ||
385 | * called under the protection of rcu_read_lock(). | ||
386 | */ | ||
387 | static int get_object(struct kmemleak_object *object) | ||
388 | { | ||
389 | return atomic_inc_not_zero(&object->use_count); | ||
390 | } | ||
391 | |||
392 | /* | ||
393 | * RCU callback to free a kmemleak_object. | ||
394 | */ | ||
395 | static void free_object_rcu(struct rcu_head *rcu) | ||
396 | { | ||
397 | struct hlist_node *elem, *tmp; | ||
398 | struct kmemleak_scan_area *area; | ||
399 | struct kmemleak_object *object = | ||
400 | container_of(rcu, struct kmemleak_object, rcu); | ||
401 | |||
402 | /* | ||
403 | * Once use_count is 0 (guaranteed by put_object), there is no other | ||
404 | * code accessing this object, hence no need for locking. | ||
405 | */ | ||
406 | hlist_for_each_entry_safe(area, elem, tmp, &object->area_list, node) { | ||
407 | hlist_del(elem); | ||
408 | kmem_cache_free(scan_area_cache, area); | ||
409 | } | ||
410 | kmem_cache_free(object_cache, object); | ||
411 | } | ||
412 | |||
413 | /* | ||
414 | * Decrement the object use_count. Once the count is 0, free the object using | ||
415 | * an RCU callback. Since put_object() may be called via the kmemleak_free() -> | ||
416 | * delete_object() path, the delayed RCU freeing ensures that there is no | ||
417 | * recursive call to the kernel allocator. Lock-less RCU object_list traversal | ||
418 | * is also possible. | ||
419 | */ | ||
420 | static void put_object(struct kmemleak_object *object) | ||
421 | { | ||
422 | if (!atomic_dec_and_test(&object->use_count)) | ||
423 | return; | ||
424 | |||
425 | /* should only get here after delete_object was called */ | ||
426 | WARN_ON(object->flags & OBJECT_ALLOCATED); | ||
427 | |||
428 | call_rcu(&object->rcu, free_object_rcu); | ||
429 | } | ||
430 | |||
431 | /* | ||
432 | * Look up an object in the prio search tree and increase its use_count. | ||
433 | */ | ||
434 | static struct kmemleak_object *find_and_get_object(unsigned long ptr, int alias) | ||
435 | { | ||
436 | unsigned long flags; | ||
437 | struct kmemleak_object *object = NULL; | ||
438 | |||
439 | rcu_read_lock(); | ||
440 | read_lock_irqsave(&kmemleak_lock, flags); | ||
441 | if (ptr >= min_addr && ptr < max_addr) | ||
442 | object = lookup_object(ptr, alias); | ||
443 | read_unlock_irqrestore(&kmemleak_lock, flags); | ||
444 | |||
445 | /* check whether the object is still available */ | ||
446 | if (object && !get_object(object)) | ||
447 | object = NULL; | ||
448 | rcu_read_unlock(); | ||
449 | |||
450 | return object; | ||
451 | } | ||
452 | |||
453 | /* | ||
454 | * Create the metadata (struct kmemleak_object) corresponding to an allocated | ||
455 | * memory block and add it to the object_list and object_tree_root. | ||
456 | */ | ||
457 | static void create_object(unsigned long ptr, size_t size, int min_count, | ||
458 | gfp_t gfp) | ||
459 | { | ||
460 | unsigned long flags; | ||
461 | struct kmemleak_object *object; | ||
462 | struct prio_tree_node *node; | ||
463 | struct stack_trace trace; | ||
464 | |||
465 | object = kmem_cache_alloc(object_cache, gfp & ~GFP_SLAB_BUG_MASK); | ||
466 | if (!object) { | ||
467 | kmemleak_panic("kmemleak: Cannot allocate a kmemleak_object " | ||
468 | "structure\n"); | ||
469 | return; | ||
470 | } | ||
471 | |||
472 | INIT_LIST_HEAD(&object->object_list); | ||
473 | INIT_LIST_HEAD(&object->gray_list); | ||
474 | INIT_HLIST_HEAD(&object->area_list); | ||
475 | spin_lock_init(&object->lock); | ||
476 | atomic_set(&object->use_count, 1); | ||
477 | object->flags = OBJECT_ALLOCATED; | ||
478 | object->pointer = ptr; | ||
479 | object->size = size; | ||
480 | object->min_count = min_count; | ||
481 | object->count = -1; /* no color initially */ | ||
482 | object->jiffies = jiffies; | ||
483 | |||
484 | /* task information */ | ||
485 | if (in_irq()) { | ||
486 | object->pid = 0; | ||
487 | strncpy(object->comm, "hardirq", sizeof(object->comm)); | ||
488 | } else if (in_softirq()) { | ||
489 | object->pid = 0; | ||
490 | strncpy(object->comm, "softirq", sizeof(object->comm)); | ||
491 | } else { | ||
492 | object->pid = current->pid; | ||
493 | /* | ||
494 | * There is a small chance of a race with set_task_comm(), | ||
495 | * however using get_task_comm() here may cause locking | ||
496 | * dependency issues with current->alloc_lock. In the worst | ||
497 | * case, the command line is not correct. | ||
498 | */ | ||
499 | strncpy(object->comm, current->comm, sizeof(object->comm)); | ||
500 | } | ||
501 | |||
502 | /* kernel backtrace */ | ||
503 | trace.max_entries = MAX_TRACE; | ||
504 | trace.nr_entries = 0; | ||
505 | trace.entries = object->trace; | ||
506 | trace.skip = 1; | ||
507 | save_stack_trace(&trace); | ||
508 | object->trace_len = trace.nr_entries; | ||
509 | |||
510 | INIT_PRIO_TREE_NODE(&object->tree_node); | ||
511 | object->tree_node.start = ptr; | ||
512 | object->tree_node.last = ptr + size - 1; | ||
513 | |||
514 | write_lock_irqsave(&kmemleak_lock, flags); | ||
515 | min_addr = min(min_addr, ptr); | ||
516 | max_addr = max(max_addr, ptr + size); | ||
517 | node = prio_tree_insert(&object_tree_root, &object->tree_node); | ||
518 | /* | ||
519 | * The code calling the kernel does not yet have the pointer to the | ||
520 | * memory block to be able to free it. However, we still hold the | ||
521 | * kmemleak_lock here in case parts of the kernel started freeing | ||
522 | * random memory blocks. | ||
523 | */ | ||
524 | if (node != &object->tree_node) { | ||
525 | unsigned long flags; | ||
526 | |||
527 | kmemleak_panic("kmemleak: Cannot insert 0x%lx into the object " | ||
528 | "search tree (already existing)\n", ptr); | ||
529 | object = lookup_object(ptr, 1); | ||
530 | spin_lock_irqsave(&object->lock, flags); | ||
531 | dump_object_info(object); | ||
532 | spin_unlock_irqrestore(&object->lock, flags); | ||
533 | |||
534 | goto out; | ||
535 | } | ||
536 | list_add_tail_rcu(&object->object_list, &object_list); | ||
537 | out: | ||
538 | write_unlock_irqrestore(&kmemleak_lock, flags); | ||
539 | } | ||
540 | |||
541 | /* | ||
542 | * Remove the metadata (struct kmemleak_object) for a memory block from the | ||
543 | * object_list and object_tree_root and decrement its use_count. | ||
544 | */ | ||
545 | static void delete_object(unsigned long ptr) | ||
546 | { | ||
547 | unsigned long flags; | ||
548 | struct kmemleak_object *object; | ||
549 | |||
550 | write_lock_irqsave(&kmemleak_lock, flags); | ||
551 | object = lookup_object(ptr, 0); | ||
552 | if (!object) { | ||
553 | kmemleak_warn("kmemleak: Freeing unknown object at 0x%08lx\n", | ||
554 | ptr); | ||
555 | write_unlock_irqrestore(&kmemleak_lock, flags); | ||
556 | return; | ||
557 | } | ||
558 | prio_tree_remove(&object_tree_root, &object->tree_node); | ||
559 | list_del_rcu(&object->object_list); | ||
560 | write_unlock_irqrestore(&kmemleak_lock, flags); | ||
561 | |||
562 | WARN_ON(!(object->flags & OBJECT_ALLOCATED)); | ||
563 | WARN_ON(atomic_read(&object->use_count) < 1); | ||
564 | |||
565 | /* | ||
566 | * Locking here also ensures that the corresponding memory block | ||
567 | * cannot be freed when it is being scanned. | ||
568 | */ | ||
569 | spin_lock_irqsave(&object->lock, flags); | ||
570 | if (object->flags & OBJECT_REPORTED) | ||
571 | print_referenced(object); | ||
572 | object->flags &= ~OBJECT_ALLOCATED; | ||
573 | spin_unlock_irqrestore(&object->lock, flags); | ||
574 | put_object(object); | ||
575 | } | ||
576 | |||
577 | /* | ||
578 | * Make a object permanently as gray-colored so that it can no longer be | ||
579 | * reported as a leak. This is used in general to mark a false positive. | ||
580 | */ | ||
581 | static void make_gray_object(unsigned long ptr) | ||
582 | { | ||
583 | unsigned long flags; | ||
584 | struct kmemleak_object *object; | ||
585 | |||
586 | object = find_and_get_object(ptr, 0); | ||
587 | if (!object) { | ||
588 | kmemleak_warn("kmemleak: Graying unknown object at 0x%08lx\n", | ||
589 | ptr); | ||
590 | return; | ||
591 | } | ||
592 | |||
593 | spin_lock_irqsave(&object->lock, flags); | ||
594 | object->min_count = 0; | ||
595 | spin_unlock_irqrestore(&object->lock, flags); | ||
596 | put_object(object); | ||
597 | } | ||
598 | |||
599 | /* | ||
600 | * Mark the object as black-colored so that it is ignored from scans and | ||
601 | * reporting. | ||
602 | */ | ||
603 | static void make_black_object(unsigned long ptr) | ||
604 | { | ||
605 | unsigned long flags; | ||
606 | struct kmemleak_object *object; | ||
607 | |||
608 | object = find_and_get_object(ptr, 0); | ||
609 | if (!object) { | ||
610 | kmemleak_warn("kmemleak: Blacking unknown object at 0x%08lx\n", | ||
611 | ptr); | ||
612 | return; | ||
613 | } | ||
614 | |||
615 | spin_lock_irqsave(&object->lock, flags); | ||
616 | object->min_count = -1; | ||
617 | spin_unlock_irqrestore(&object->lock, flags); | ||
618 | put_object(object); | ||
619 | } | ||
620 | |||
621 | /* | ||
622 | * Add a scanning area to the object. If at least one such area is added, | ||
623 | * kmemleak will only scan these ranges rather than the whole memory block. | ||
624 | */ | ||
625 | static void add_scan_area(unsigned long ptr, unsigned long offset, | ||
626 | size_t length, gfp_t gfp) | ||
627 | { | ||
628 | unsigned long flags; | ||
629 | struct kmemleak_object *object; | ||
630 | struct kmemleak_scan_area *area; | ||
631 | |||
632 | object = find_and_get_object(ptr, 0); | ||
633 | if (!object) { | ||
634 | kmemleak_warn("kmemleak: Adding scan area to unknown " | ||
635 | "object at 0x%08lx\n", ptr); | ||
636 | return; | ||
637 | } | ||
638 | |||
639 | area = kmem_cache_alloc(scan_area_cache, gfp & ~GFP_SLAB_BUG_MASK); | ||
640 | if (!area) { | ||
641 | kmemleak_warn("kmemleak: Cannot allocate a scan area\n"); | ||
642 | goto out; | ||
643 | } | ||
644 | |||
645 | spin_lock_irqsave(&object->lock, flags); | ||
646 | if (offset + length > object->size) { | ||
647 | kmemleak_warn("kmemleak: Scan area larger than object " | ||
648 | "0x%08lx\n", ptr); | ||
649 | dump_object_info(object); | ||
650 | kmem_cache_free(scan_area_cache, area); | ||
651 | goto out_unlock; | ||
652 | } | ||
653 | |||
654 | INIT_HLIST_NODE(&area->node); | ||
655 | area->offset = offset; | ||
656 | area->length = length; | ||
657 | |||
658 | hlist_add_head(&area->node, &object->area_list); | ||
659 | out_unlock: | ||
660 | spin_unlock_irqrestore(&object->lock, flags); | ||
661 | out: | ||
662 | put_object(object); | ||
663 | } | ||
664 | |||
665 | /* | ||
666 | * Set the OBJECT_NO_SCAN flag for the object corresponding to the give | ||
667 | * pointer. Such object will not be scanned by kmemleak but references to it | ||
668 | * are searched. | ||
669 | */ | ||
670 | static void object_no_scan(unsigned long ptr) | ||
671 | { | ||
672 | unsigned long flags; | ||
673 | struct kmemleak_object *object; | ||
674 | |||
675 | object = find_and_get_object(ptr, 0); | ||
676 | if (!object) { | ||
677 | kmemleak_warn("kmemleak: Not scanning unknown object at " | ||
678 | "0x%08lx\n", ptr); | ||
679 | return; | ||
680 | } | ||
681 | |||
682 | spin_lock_irqsave(&object->lock, flags); | ||
683 | object->flags |= OBJECT_NO_SCAN; | ||
684 | spin_unlock_irqrestore(&object->lock, flags); | ||
685 | put_object(object); | ||
686 | } | ||
687 | |||
688 | /* | ||
689 | * Log an early kmemleak_* call to the early_log buffer. These calls will be | ||
690 | * processed later once kmemleak is fully initialized. | ||
691 | */ | ||
692 | static void log_early(int op_type, const void *ptr, size_t size, | ||
693 | int min_count, unsigned long offset, size_t length) | ||
694 | { | ||
695 | unsigned long flags; | ||
696 | struct early_log *log; | ||
697 | |||
698 | if (crt_early_log >= ARRAY_SIZE(early_log)) { | ||
699 | kmemleak_panic("kmemleak: Early log buffer exceeded\n"); | ||
700 | return; | ||
701 | } | ||
702 | |||
703 | /* | ||
704 | * There is no need for locking since the kernel is still in UP mode | ||
705 | * at this stage. Disabling the IRQs is enough. | ||
706 | */ | ||
707 | local_irq_save(flags); | ||
708 | log = &early_log[crt_early_log]; | ||
709 | log->op_type = op_type; | ||
710 | log->ptr = ptr; | ||
711 | log->size = size; | ||
712 | log->min_count = min_count; | ||
713 | log->offset = offset; | ||
714 | log->length = length; | ||
715 | crt_early_log++; | ||
716 | local_irq_restore(flags); | ||
717 | } | ||
718 | |||
719 | /* | ||
720 | * Memory allocation function callback. This function is called from the | ||
721 | * kernel allocators when a new block is allocated (kmem_cache_alloc, kmalloc, | ||
722 | * vmalloc etc.). | ||
723 | */ | ||
724 | void kmemleak_alloc(const void *ptr, size_t size, int min_count, gfp_t gfp) | ||
725 | { | ||
726 | pr_debug("%s(0x%p, %zu, %d)\n", __func__, ptr, size, min_count); | ||
727 | |||
728 | if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) | ||
729 | create_object((unsigned long)ptr, size, min_count, gfp); | ||
730 | else if (atomic_read(&kmemleak_early_log)) | ||
731 | log_early(KMEMLEAK_ALLOC, ptr, size, min_count, 0, 0); | ||
732 | } | ||
733 | EXPORT_SYMBOL_GPL(kmemleak_alloc); | ||
734 | |||
735 | /* | ||
736 | * Memory freeing function callback. This function is called from the kernel | ||
737 | * allocators when a block is freed (kmem_cache_free, kfree, vfree etc.). | ||
738 | */ | ||
739 | void kmemleak_free(const void *ptr) | ||
740 | { | ||
741 | pr_debug("%s(0x%p)\n", __func__, ptr); | ||
742 | |||
743 | if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) | ||
744 | delete_object((unsigned long)ptr); | ||
745 | else if (atomic_read(&kmemleak_early_log)) | ||
746 | log_early(KMEMLEAK_FREE, ptr, 0, 0, 0, 0); | ||
747 | } | ||
748 | EXPORT_SYMBOL_GPL(kmemleak_free); | ||
749 | |||
750 | /* | ||
751 | * Mark an already allocated memory block as a false positive. This will cause | ||
752 | * the block to no longer be reported as leak and always be scanned. | ||
753 | */ | ||
754 | void kmemleak_not_leak(const void *ptr) | ||
755 | { | ||
756 | pr_debug("%s(0x%p)\n", __func__, ptr); | ||
757 | |||
758 | if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) | ||
759 | make_gray_object((unsigned long)ptr); | ||
760 | else if (atomic_read(&kmemleak_early_log)) | ||
761 | log_early(KMEMLEAK_NOT_LEAK, ptr, 0, 0, 0, 0); | ||
762 | } | ||
763 | EXPORT_SYMBOL(kmemleak_not_leak); | ||
764 | |||
765 | /* | ||
766 | * Ignore a memory block. This is usually done when it is known that the | ||
767 | * corresponding block is not a leak and does not contain any references to | ||
768 | * other allocated memory blocks. | ||
769 | */ | ||
770 | void kmemleak_ignore(const void *ptr) | ||
771 | { | ||
772 | pr_debug("%s(0x%p)\n", __func__, ptr); | ||
773 | |||
774 | if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) | ||
775 | make_black_object((unsigned long)ptr); | ||
776 | else if (atomic_read(&kmemleak_early_log)) | ||
777 | log_early(KMEMLEAK_IGNORE, ptr, 0, 0, 0, 0); | ||
778 | } | ||
779 | EXPORT_SYMBOL(kmemleak_ignore); | ||
780 | |||
781 | /* | ||
782 | * Limit the range to be scanned in an allocated memory block. | ||
783 | */ | ||
784 | void kmemleak_scan_area(const void *ptr, unsigned long offset, size_t length, | ||
785 | gfp_t gfp) | ||
786 | { | ||
787 | pr_debug("%s(0x%p)\n", __func__, ptr); | ||
788 | |||
789 | if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) | ||
790 | add_scan_area((unsigned long)ptr, offset, length, gfp); | ||
791 | else if (atomic_read(&kmemleak_early_log)) | ||
792 | log_early(KMEMLEAK_SCAN_AREA, ptr, 0, 0, offset, length); | ||
793 | } | ||
794 | EXPORT_SYMBOL(kmemleak_scan_area); | ||
795 | |||
796 | /* | ||
797 | * Inform kmemleak not to scan the given memory block. | ||
798 | */ | ||
799 | void kmemleak_no_scan(const void *ptr) | ||
800 | { | ||
801 | pr_debug("%s(0x%p)\n", __func__, ptr); | ||
802 | |||
803 | if (atomic_read(&kmemleak_enabled) && ptr && !IS_ERR(ptr)) | ||
804 | object_no_scan((unsigned long)ptr); | ||
805 | else if (atomic_read(&kmemleak_early_log)) | ||
806 | log_early(KMEMLEAK_NO_SCAN, ptr, 0, 0, 0, 0); | ||
807 | } | ||
808 | EXPORT_SYMBOL(kmemleak_no_scan); | ||
809 | |||
810 | /* | ||
811 | * Yield the CPU so that other tasks get a chance to run. The yielding is | ||
812 | * rate-limited to avoid excessive number of calls to the schedule() function | ||
813 | * during memory scanning. | ||
814 | */ | ||
815 | static void scan_yield(void) | ||
816 | { | ||
817 | might_sleep(); | ||
818 | |||
819 | if (time_is_before_eq_jiffies(next_scan_yield)) { | ||
820 | schedule(); | ||
821 | next_scan_yield = jiffies + jiffies_scan_yield; | ||
822 | } | ||
823 | } | ||
824 | |||
825 | /* | ||
826 | * Memory scanning is a long process and it needs to be interruptable. This | ||
827 | * function checks whether such interrupt condition occured. | ||
828 | */ | ||
829 | static int scan_should_stop(void) | ||
830 | { | ||
831 | if (!atomic_read(&kmemleak_enabled)) | ||
832 | return 1; | ||
833 | |||
834 | /* | ||
835 | * This function may be called from either process or kthread context, | ||
836 | * hence the need to check for both stop conditions. | ||
837 | */ | ||
838 | if (current->mm) | ||
839 | return signal_pending(current); | ||
840 | else | ||
841 | return kthread_should_stop(); | ||
842 | |||
843 | return 0; | ||
844 | } | ||
845 | |||
846 | /* | ||
847 | * Scan a memory block (exclusive range) for valid pointers and add those | ||
848 | * found to the gray list. | ||
849 | */ | ||
850 | static void scan_block(void *_start, void *_end, | ||
851 | struct kmemleak_object *scanned) | ||
852 | { | ||
853 | unsigned long *ptr; | ||
854 | unsigned long *start = PTR_ALIGN(_start, BYTES_PER_POINTER); | ||
855 | unsigned long *end = _end - (BYTES_PER_POINTER - 1); | ||
856 | |||
857 | for (ptr = start; ptr < end; ptr++) { | ||
858 | unsigned long flags; | ||
859 | unsigned long pointer = *ptr; | ||
860 | struct kmemleak_object *object; | ||
861 | |||
862 | if (scan_should_stop()) | ||
863 | break; | ||
864 | |||
865 | /* | ||
866 | * When scanning a memory block with a corresponding | ||
867 | * kmemleak_object, the CPU yielding is handled in the calling | ||
868 | * code since it holds the object->lock to avoid the block | ||
869 | * freeing. | ||
870 | */ | ||
871 | if (!scanned) | ||
872 | scan_yield(); | ||
873 | |||
874 | object = find_and_get_object(pointer, 1); | ||
875 | if (!object) | ||
876 | continue; | ||
877 | if (object == scanned) { | ||
878 | /* self referenced, ignore */ | ||
879 | put_object(object); | ||
880 | continue; | ||
881 | } | ||
882 | |||
883 | /* | ||
884 | * Avoid the lockdep recursive warning on object->lock being | ||
885 | * previously acquired in scan_object(). These locks are | ||
886 | * enclosed by scan_mutex. | ||
887 | */ | ||
888 | spin_lock_irqsave_nested(&object->lock, flags, | ||
889 | SINGLE_DEPTH_NESTING); | ||
890 | if (!color_white(object)) { | ||
891 | /* non-orphan, ignored or new */ | ||
892 | spin_unlock_irqrestore(&object->lock, flags); | ||
893 | put_object(object); | ||
894 | continue; | ||
895 | } | ||
896 | |||
897 | /* | ||
898 | * Increase the object's reference count (number of pointers | ||
899 | * to the memory block). If this count reaches the required | ||
900 | * minimum, the object's color will become gray and it will be | ||
901 | * added to the gray_list. | ||
902 | */ | ||
903 | object->count++; | ||
904 | if (color_gray(object)) | ||
905 | list_add_tail(&object->gray_list, &gray_list); | ||
906 | else | ||
907 | put_object(object); | ||
908 | spin_unlock_irqrestore(&object->lock, flags); | ||
909 | } | ||
910 | } | ||
911 | |||
912 | /* | ||
913 | * Scan a memory block corresponding to a kmemleak_object. A condition is | ||
914 | * that object->use_count >= 1. | ||
915 | */ | ||
916 | static void scan_object(struct kmemleak_object *object) | ||
917 | { | ||
918 | struct kmemleak_scan_area *area; | ||
919 | struct hlist_node *elem; | ||
920 | unsigned long flags; | ||
921 | |||
922 | /* | ||
923 | * Once the object->lock is aquired, the corresponding memory block | ||
924 | * cannot be freed (the same lock is aquired in delete_object). | ||
925 | */ | ||
926 | spin_lock_irqsave(&object->lock, flags); | ||
927 | if (object->flags & OBJECT_NO_SCAN) | ||
928 | goto out; | ||
929 | if (!(object->flags & OBJECT_ALLOCATED)) | ||
930 | /* already freed object */ | ||
931 | goto out; | ||
932 | if (hlist_empty(&object->area_list)) | ||
933 | scan_block((void *)object->pointer, | ||
934 | (void *)(object->pointer + object->size), object); | ||
935 | else | ||
936 | hlist_for_each_entry(area, elem, &object->area_list, node) | ||
937 | scan_block((void *)(object->pointer + area->offset), | ||
938 | (void *)(object->pointer + area->offset | ||
939 | + area->length), object); | ||
940 | out: | ||
941 | spin_unlock_irqrestore(&object->lock, flags); | ||
942 | } | ||
943 | |||
944 | /* | ||
945 | * Scan data sections and all the referenced memory blocks allocated via the | ||
946 | * kernel's standard allocators. This function must be called with the | ||
947 | * scan_mutex held. | ||
948 | */ | ||
949 | static void kmemleak_scan(void) | ||
950 | { | ||
951 | unsigned long flags; | ||
952 | struct kmemleak_object *object, *tmp; | ||
953 | struct task_struct *task; | ||
954 | int i; | ||
955 | |||
956 | /* prepare the kmemleak_object's */ | ||
957 | rcu_read_lock(); | ||
958 | list_for_each_entry_rcu(object, &object_list, object_list) { | ||
959 | spin_lock_irqsave(&object->lock, flags); | ||
960 | #ifdef DEBUG | ||
961 | /* | ||
962 | * With a few exceptions there should be a maximum of | ||
963 | * 1 reference to any object at this point. | ||
964 | */ | ||
965 | if (atomic_read(&object->use_count) > 1) { | ||
966 | pr_debug("kmemleak: object->use_count = %d\n", | ||
967 | atomic_read(&object->use_count)); | ||
968 | dump_object_info(object); | ||
969 | } | ||
970 | #endif | ||
971 | /* reset the reference count (whiten the object) */ | ||
972 | object->count = 0; | ||
973 | if (color_gray(object) && get_object(object)) | ||
974 | list_add_tail(&object->gray_list, &gray_list); | ||
975 | |||
976 | spin_unlock_irqrestore(&object->lock, flags); | ||
977 | } | ||
978 | rcu_read_unlock(); | ||
979 | |||
980 | /* data/bss scanning */ | ||
981 | scan_block(_sdata, _edata, NULL); | ||
982 | scan_block(__bss_start, __bss_stop, NULL); | ||
983 | |||
984 | #ifdef CONFIG_SMP | ||
985 | /* per-cpu sections scanning */ | ||
986 | for_each_possible_cpu(i) | ||
987 | scan_block(__per_cpu_start + per_cpu_offset(i), | ||
988 | __per_cpu_end + per_cpu_offset(i), NULL); | ||
989 | #endif | ||
990 | |||
991 | /* | ||
992 | * Struct page scanning for each node. The code below is not yet safe | ||
993 | * with MEMORY_HOTPLUG. | ||
994 | */ | ||
995 | for_each_online_node(i) { | ||
996 | pg_data_t *pgdat = NODE_DATA(i); | ||
997 | unsigned long start_pfn = pgdat->node_start_pfn; | ||
998 | unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages; | ||
999 | unsigned long pfn; | ||
1000 | |||
1001 | for (pfn = start_pfn; pfn < end_pfn; pfn++) { | ||
1002 | struct page *page; | ||
1003 | |||
1004 | if (!pfn_valid(pfn)) | ||
1005 | continue; | ||
1006 | page = pfn_to_page(pfn); | ||
1007 | /* only scan if page is in use */ | ||
1008 | if (page_count(page) == 0) | ||
1009 | continue; | ||
1010 | scan_block(page, page + 1, NULL); | ||
1011 | } | ||
1012 | } | ||
1013 | |||
1014 | /* | ||
1015 | * Scanning the task stacks may introduce false negatives and it is | ||
1016 | * not enabled by default. | ||
1017 | */ | ||
1018 | if (kmemleak_stack_scan) { | ||
1019 | read_lock(&tasklist_lock); | ||
1020 | for_each_process(task) | ||
1021 | scan_block(task_stack_page(task), | ||
1022 | task_stack_page(task) + THREAD_SIZE, NULL); | ||
1023 | read_unlock(&tasklist_lock); | ||
1024 | } | ||
1025 | |||
1026 | /* | ||
1027 | * Scan the objects already referenced from the sections scanned | ||
1028 | * above. More objects will be referenced and, if there are no memory | ||
1029 | * leaks, all the objects will be scanned. The list traversal is safe | ||
1030 | * for both tail additions and removals from inside the loop. The | ||
1031 | * kmemleak objects cannot be freed from outside the loop because their | ||
1032 | * use_count was increased. | ||
1033 | */ | ||
1034 | object = list_entry(gray_list.next, typeof(*object), gray_list); | ||
1035 | while (&object->gray_list != &gray_list) { | ||
1036 | scan_yield(); | ||
1037 | |||
1038 | /* may add new objects to the list */ | ||
1039 | if (!scan_should_stop()) | ||
1040 | scan_object(object); | ||
1041 | |||
1042 | tmp = list_entry(object->gray_list.next, typeof(*object), | ||
1043 | gray_list); | ||
1044 | |||
1045 | /* remove the object from the list and release it */ | ||
1046 | list_del(&object->gray_list); | ||
1047 | put_object(object); | ||
1048 | |||
1049 | object = tmp; | ||
1050 | } | ||
1051 | WARN_ON(!list_empty(&gray_list)); | ||
1052 | } | ||
1053 | |||
1054 | /* | ||
1055 | * Thread function performing automatic memory scanning. Unreferenced objects | ||
1056 | * at the end of a memory scan are reported but only the first time. | ||
1057 | */ | ||
1058 | static int kmemleak_scan_thread(void *arg) | ||
1059 | { | ||
1060 | static int first_run = 1; | ||
1061 | |||
1062 | pr_info("kmemleak: Automatic memory scanning thread started\n"); | ||
1063 | |||
1064 | /* | ||
1065 | * Wait before the first scan to allow the system to fully initialize. | ||
1066 | */ | ||
1067 | if (first_run) { | ||
1068 | first_run = 0; | ||
1069 | ssleep(SECS_FIRST_SCAN); | ||
1070 | } | ||
1071 | |||
1072 | while (!kthread_should_stop()) { | ||
1073 | struct kmemleak_object *object; | ||
1074 | signed long timeout = jiffies_scan_wait; | ||
1075 | |||
1076 | mutex_lock(&scan_mutex); | ||
1077 | |||
1078 | kmemleak_scan(); | ||
1079 | reported_leaks = 0; | ||
1080 | |||
1081 | rcu_read_lock(); | ||
1082 | list_for_each_entry_rcu(object, &object_list, object_list) { | ||
1083 | unsigned long flags; | ||
1084 | |||
1085 | if (reported_leaks >= REPORTS_NR) | ||
1086 | break; | ||
1087 | spin_lock_irqsave(&object->lock, flags); | ||
1088 | if (!(object->flags & OBJECT_REPORTED) && | ||
1089 | unreferenced_object(object)) { | ||
1090 | print_unreferenced(NULL, object); | ||
1091 | object->flags |= OBJECT_REPORTED; | ||
1092 | reported_leaks++; | ||
1093 | } else if ((object->flags & OBJECT_REPORTED) && | ||
1094 | referenced_object(object)) { | ||
1095 | print_referenced(object); | ||
1096 | object->flags &= ~OBJECT_REPORTED; | ||
1097 | } | ||
1098 | spin_unlock_irqrestore(&object->lock, flags); | ||
1099 | } | ||
1100 | rcu_read_unlock(); | ||
1101 | |||
1102 | mutex_unlock(&scan_mutex); | ||
1103 | /* wait before the next scan */ | ||
1104 | while (timeout && !kthread_should_stop()) | ||
1105 | timeout = schedule_timeout_interruptible(timeout); | ||
1106 | } | ||
1107 | |||
1108 | pr_info("kmemleak: Automatic memory scanning thread ended\n"); | ||
1109 | |||
1110 | return 0; | ||
1111 | } | ||
1112 | |||
1113 | /* | ||
1114 | * Start the automatic memory scanning thread. This function must be called | ||
1115 | * with the kmemleak_mutex held. | ||
1116 | */ | ||
1117 | void start_scan_thread(void) | ||
1118 | { | ||
1119 | if (scan_thread) | ||
1120 | return; | ||
1121 | scan_thread = kthread_run(kmemleak_scan_thread, NULL, "kmemleak"); | ||
1122 | if (IS_ERR(scan_thread)) { | ||
1123 | pr_warning("kmemleak: Failed to create the scan thread\n"); | ||
1124 | scan_thread = NULL; | ||
1125 | } | ||
1126 | } | ||
1127 | |||
1128 | /* | ||
1129 | * Stop the automatic memory scanning thread. This function must be called | ||
1130 | * with the kmemleak_mutex held. | ||
1131 | */ | ||
1132 | void stop_scan_thread(void) | ||
1133 | { | ||
1134 | if (scan_thread) { | ||
1135 | kthread_stop(scan_thread); | ||
1136 | scan_thread = NULL; | ||
1137 | } | ||
1138 | } | ||
1139 | |||
1140 | /* | ||
1141 | * Iterate over the object_list and return the first valid object at or after | ||
1142 | * the required position with its use_count incremented. The function triggers | ||
1143 | * a memory scanning when the pos argument points to the first position. | ||
1144 | */ | ||
1145 | static void *kmemleak_seq_start(struct seq_file *seq, loff_t *pos) | ||
1146 | { | ||
1147 | struct kmemleak_object *object; | ||
1148 | loff_t n = *pos; | ||
1149 | |||
1150 | if (!n) { | ||
1151 | kmemleak_scan(); | ||
1152 | reported_leaks = 0; | ||
1153 | } | ||
1154 | if (reported_leaks >= REPORTS_NR) | ||
1155 | return NULL; | ||
1156 | |||
1157 | rcu_read_lock(); | ||
1158 | list_for_each_entry_rcu(object, &object_list, object_list) { | ||
1159 | if (n-- > 0) | ||
1160 | continue; | ||
1161 | if (get_object(object)) | ||
1162 | goto out; | ||
1163 | } | ||
1164 | object = NULL; | ||
1165 | out: | ||
1166 | rcu_read_unlock(); | ||
1167 | return object; | ||
1168 | } | ||
1169 | |||
1170 | /* | ||
1171 | * Return the next object in the object_list. The function decrements the | ||
1172 | * use_count of the previous object and increases that of the next one. | ||
1173 | */ | ||
1174 | static void *kmemleak_seq_next(struct seq_file *seq, void *v, loff_t *pos) | ||
1175 | { | ||
1176 | struct kmemleak_object *prev_obj = v; | ||
1177 | struct kmemleak_object *next_obj = NULL; | ||
1178 | struct list_head *n = &prev_obj->object_list; | ||
1179 | |||
1180 | ++(*pos); | ||
1181 | if (reported_leaks >= REPORTS_NR) | ||
1182 | goto out; | ||
1183 | |||
1184 | rcu_read_lock(); | ||
1185 | list_for_each_continue_rcu(n, &object_list) { | ||
1186 | next_obj = list_entry(n, struct kmemleak_object, object_list); | ||
1187 | if (get_object(next_obj)) | ||
1188 | break; | ||
1189 | } | ||
1190 | rcu_read_unlock(); | ||
1191 | out: | ||
1192 | put_object(prev_obj); | ||
1193 | return next_obj; | ||
1194 | } | ||
1195 | |||
1196 | /* | ||
1197 | * Decrement the use_count of the last object required, if any. | ||
1198 | */ | ||
1199 | static void kmemleak_seq_stop(struct seq_file *seq, void *v) | ||
1200 | { | ||
1201 | if (v) | ||
1202 | put_object(v); | ||
1203 | } | ||
1204 | |||
1205 | /* | ||
1206 | * Print the information for an unreferenced object to the seq file. | ||
1207 | */ | ||
1208 | static int kmemleak_seq_show(struct seq_file *seq, void *v) | ||
1209 | { | ||
1210 | struct kmemleak_object *object = v; | ||
1211 | unsigned long flags; | ||
1212 | |||
1213 | spin_lock_irqsave(&object->lock, flags); | ||
1214 | if (!unreferenced_object(object)) | ||
1215 | goto out; | ||
1216 | print_unreferenced(seq, object); | ||
1217 | reported_leaks++; | ||
1218 | out: | ||
1219 | spin_unlock_irqrestore(&object->lock, flags); | ||
1220 | return 0; | ||
1221 | } | ||
1222 | |||
1223 | static const struct seq_operations kmemleak_seq_ops = { | ||
1224 | .start = kmemleak_seq_start, | ||
1225 | .next = kmemleak_seq_next, | ||
1226 | .stop = kmemleak_seq_stop, | ||
1227 | .show = kmemleak_seq_show, | ||
1228 | }; | ||
1229 | |||
1230 | static int kmemleak_open(struct inode *inode, struct file *file) | ||
1231 | { | ||
1232 | int ret = 0; | ||
1233 | |||
1234 | if (!atomic_read(&kmemleak_enabled)) | ||
1235 | return -EBUSY; | ||
1236 | |||
1237 | ret = mutex_lock_interruptible(&kmemleak_mutex); | ||
1238 | if (ret < 0) | ||
1239 | goto out; | ||
1240 | if (file->f_mode & FMODE_READ) { | ||
1241 | ret = mutex_lock_interruptible(&scan_mutex); | ||
1242 | if (ret < 0) | ||
1243 | goto kmemleak_unlock; | ||
1244 | ret = seq_open(file, &kmemleak_seq_ops); | ||
1245 | if (ret < 0) | ||
1246 | goto scan_unlock; | ||
1247 | } | ||
1248 | return ret; | ||
1249 | |||
1250 | scan_unlock: | ||
1251 | mutex_unlock(&scan_mutex); | ||
1252 | kmemleak_unlock: | ||
1253 | mutex_unlock(&kmemleak_mutex); | ||
1254 | out: | ||
1255 | return ret; | ||
1256 | } | ||
1257 | |||
1258 | static int kmemleak_release(struct inode *inode, struct file *file) | ||
1259 | { | ||
1260 | int ret = 0; | ||
1261 | |||
1262 | if (file->f_mode & FMODE_READ) { | ||
1263 | seq_release(inode, file); | ||
1264 | mutex_unlock(&scan_mutex); | ||
1265 | } | ||
1266 | mutex_unlock(&kmemleak_mutex); | ||
1267 | |||
1268 | return ret; | ||
1269 | } | ||
1270 | |||
1271 | /* | ||
1272 | * File write operation to configure kmemleak at run-time. The following | ||
1273 | * commands can be written to the /sys/kernel/debug/kmemleak file: | ||
1274 | * off - disable kmemleak (irreversible) | ||
1275 | * stack=on - enable the task stacks scanning | ||
1276 | * stack=off - disable the tasks stacks scanning | ||
1277 | * scan=on - start the automatic memory scanning thread | ||
1278 | * scan=off - stop the automatic memory scanning thread | ||
1279 | * scan=... - set the automatic memory scanning period in seconds (0 to | ||
1280 | * disable it) | ||
1281 | */ | ||
1282 | static ssize_t kmemleak_write(struct file *file, const char __user *user_buf, | ||
1283 | size_t size, loff_t *ppos) | ||
1284 | { | ||
1285 | char buf[64]; | ||
1286 | int buf_size; | ||
1287 | |||
1288 | if (!atomic_read(&kmemleak_enabled)) | ||
1289 | return -EBUSY; | ||
1290 | |||
1291 | buf_size = min(size, (sizeof(buf) - 1)); | ||
1292 | if (strncpy_from_user(buf, user_buf, buf_size) < 0) | ||
1293 | return -EFAULT; | ||
1294 | buf[buf_size] = 0; | ||
1295 | |||
1296 | if (strncmp(buf, "off", 3) == 0) | ||
1297 | kmemleak_disable(); | ||
1298 | else if (strncmp(buf, "stack=on", 8) == 0) | ||
1299 | kmemleak_stack_scan = 1; | ||
1300 | else if (strncmp(buf, "stack=off", 9) == 0) | ||
1301 | kmemleak_stack_scan = 0; | ||
1302 | else if (strncmp(buf, "scan=on", 7) == 0) | ||
1303 | start_scan_thread(); | ||
1304 | else if (strncmp(buf, "scan=off", 8) == 0) | ||
1305 | stop_scan_thread(); | ||
1306 | else if (strncmp(buf, "scan=", 5) == 0) { | ||
1307 | unsigned long secs; | ||
1308 | int err; | ||
1309 | |||
1310 | err = strict_strtoul(buf + 5, 0, &secs); | ||
1311 | if (err < 0) | ||
1312 | return err; | ||
1313 | stop_scan_thread(); | ||
1314 | if (secs) { | ||
1315 | jiffies_scan_wait = msecs_to_jiffies(secs * 1000); | ||
1316 | start_scan_thread(); | ||
1317 | } | ||
1318 | } else | ||
1319 | return -EINVAL; | ||
1320 | |||
1321 | /* ignore the rest of the buffer, only one command at a time */ | ||
1322 | *ppos += size; | ||
1323 | return size; | ||
1324 | } | ||
1325 | |||
1326 | static const struct file_operations kmemleak_fops = { | ||
1327 | .owner = THIS_MODULE, | ||
1328 | .open = kmemleak_open, | ||
1329 | .read = seq_read, | ||
1330 | .write = kmemleak_write, | ||
1331 | .llseek = seq_lseek, | ||
1332 | .release = kmemleak_release, | ||
1333 | }; | ||
1334 | |||
1335 | /* | ||
1336 | * Perform the freeing of the kmemleak internal objects after waiting for any | ||
1337 | * current memory scan to complete. | ||
1338 | */ | ||
1339 | static int kmemleak_cleanup_thread(void *arg) | ||
1340 | { | ||
1341 | struct kmemleak_object *object; | ||
1342 | |||
1343 | mutex_lock(&kmemleak_mutex); | ||
1344 | stop_scan_thread(); | ||
1345 | mutex_unlock(&kmemleak_mutex); | ||
1346 | |||
1347 | mutex_lock(&scan_mutex); | ||
1348 | rcu_read_lock(); | ||
1349 | list_for_each_entry_rcu(object, &object_list, object_list) | ||
1350 | delete_object(object->pointer); | ||
1351 | rcu_read_unlock(); | ||
1352 | mutex_unlock(&scan_mutex); | ||
1353 | |||
1354 | return 0; | ||
1355 | } | ||
1356 | |||
1357 | /* | ||
1358 | * Start the clean-up thread. | ||
1359 | */ | ||
1360 | static void kmemleak_cleanup(void) | ||
1361 | { | ||
1362 | struct task_struct *cleanup_thread; | ||
1363 | |||
1364 | cleanup_thread = kthread_run(kmemleak_cleanup_thread, NULL, | ||
1365 | "kmemleak-clean"); | ||
1366 | if (IS_ERR(cleanup_thread)) | ||
1367 | pr_warning("kmemleak: Failed to create the clean-up thread\n"); | ||
1368 | } | ||
1369 | |||
1370 | /* | ||
1371 | * Disable kmemleak. No memory allocation/freeing will be traced once this | ||
1372 | * function is called. Disabling kmemleak is an irreversible operation. | ||
1373 | */ | ||
1374 | static void kmemleak_disable(void) | ||
1375 | { | ||
1376 | /* atomically check whether it was already invoked */ | ||
1377 | if (atomic_cmpxchg(&kmemleak_error, 0, 1)) | ||
1378 | return; | ||
1379 | |||
1380 | /* stop any memory operation tracing */ | ||
1381 | atomic_set(&kmemleak_early_log, 0); | ||
1382 | atomic_set(&kmemleak_enabled, 0); | ||
1383 | |||
1384 | /* check whether it is too early for a kernel thread */ | ||
1385 | if (atomic_read(&kmemleak_initialized)) | ||
1386 | kmemleak_cleanup(); | ||
1387 | |||
1388 | pr_info("Kernel memory leak detector disabled\n"); | ||
1389 | } | ||
1390 | |||
1391 | /* | ||
1392 | * Allow boot-time kmemleak disabling (enabled by default). | ||
1393 | */ | ||
1394 | static int kmemleak_boot_config(char *str) | ||
1395 | { | ||
1396 | if (!str) | ||
1397 | return -EINVAL; | ||
1398 | if (strcmp(str, "off") == 0) | ||
1399 | kmemleak_disable(); | ||
1400 | else if (strcmp(str, "on") != 0) | ||
1401 | return -EINVAL; | ||
1402 | return 0; | ||
1403 | } | ||
1404 | early_param("kmemleak", kmemleak_boot_config); | ||
1405 | |||
1406 | /* | ||
1407 | * Kkmemleak initialization. | ||
1408 | */ | ||
1409 | void __init kmemleak_init(void) | ||
1410 | { | ||
1411 | int i; | ||
1412 | unsigned long flags; | ||
1413 | |||
1414 | jiffies_scan_yield = msecs_to_jiffies(MSECS_SCAN_YIELD); | ||
1415 | jiffies_min_age = msecs_to_jiffies(MSECS_MIN_AGE); | ||
1416 | jiffies_scan_wait = msecs_to_jiffies(SECS_SCAN_WAIT * 1000); | ||
1417 | |||
1418 | object_cache = KMEM_CACHE(kmemleak_object, SLAB_NOLEAKTRACE); | ||
1419 | scan_area_cache = KMEM_CACHE(kmemleak_scan_area, SLAB_NOLEAKTRACE); | ||
1420 | INIT_PRIO_TREE_ROOT(&object_tree_root); | ||
1421 | |||
1422 | /* the kernel is still in UP mode, so disabling the IRQs is enough */ | ||
1423 | local_irq_save(flags); | ||
1424 | if (!atomic_read(&kmemleak_error)) { | ||
1425 | atomic_set(&kmemleak_enabled, 1); | ||
1426 | atomic_set(&kmemleak_early_log, 0); | ||
1427 | } | ||
1428 | local_irq_restore(flags); | ||
1429 | |||
1430 | /* | ||
1431 | * This is the point where tracking allocations is safe. Automatic | ||
1432 | * scanning is started during the late initcall. Add the early logged | ||
1433 | * callbacks to the kmemleak infrastructure. | ||
1434 | */ | ||
1435 | for (i = 0; i < crt_early_log; i++) { | ||
1436 | struct early_log *log = &early_log[i]; | ||
1437 | |||
1438 | switch (log->op_type) { | ||
1439 | case KMEMLEAK_ALLOC: | ||
1440 | kmemleak_alloc(log->ptr, log->size, log->min_count, | ||
1441 | GFP_KERNEL); | ||
1442 | break; | ||
1443 | case KMEMLEAK_FREE: | ||
1444 | kmemleak_free(log->ptr); | ||
1445 | break; | ||
1446 | case KMEMLEAK_NOT_LEAK: | ||
1447 | kmemleak_not_leak(log->ptr); | ||
1448 | break; | ||
1449 | case KMEMLEAK_IGNORE: | ||
1450 | kmemleak_ignore(log->ptr); | ||
1451 | break; | ||
1452 | case KMEMLEAK_SCAN_AREA: | ||
1453 | kmemleak_scan_area(log->ptr, log->offset, log->length, | ||
1454 | GFP_KERNEL); | ||
1455 | break; | ||
1456 | case KMEMLEAK_NO_SCAN: | ||
1457 | kmemleak_no_scan(log->ptr); | ||
1458 | break; | ||
1459 | default: | ||
1460 | WARN_ON(1); | ||
1461 | } | ||
1462 | } | ||
1463 | } | ||
1464 | |||
1465 | /* | ||
1466 | * Late initialization function. | ||
1467 | */ | ||
1468 | static int __init kmemleak_late_init(void) | ||
1469 | { | ||
1470 | struct dentry *dentry; | ||
1471 | |||
1472 | atomic_set(&kmemleak_initialized, 1); | ||
1473 | |||
1474 | if (atomic_read(&kmemleak_error)) { | ||
1475 | /* | ||
1476 | * Some error occured and kmemleak was disabled. There is a | ||
1477 | * small chance that kmemleak_disable() was called immediately | ||
1478 | * after setting kmemleak_initialized and we may end up with | ||
1479 | * two clean-up threads but serialized by scan_mutex. | ||
1480 | */ | ||
1481 | kmemleak_cleanup(); | ||
1482 | return -ENOMEM; | ||
1483 | } | ||
1484 | |||
1485 | dentry = debugfs_create_file("kmemleak", S_IRUGO, NULL, NULL, | ||
1486 | &kmemleak_fops); | ||
1487 | if (!dentry) | ||
1488 | pr_warning("kmemleak: Failed to create the debugfs kmemleak " | ||
1489 | "file\n"); | ||
1490 | mutex_lock(&kmemleak_mutex); | ||
1491 | start_scan_thread(); | ||
1492 | mutex_unlock(&kmemleak_mutex); | ||
1493 | |||
1494 | pr_info("Kernel memory leak detector initialized\n"); | ||
1495 | |||
1496 | return 0; | ||
1497 | } | ||
1498 | late_initcall(kmemleak_late_init); | ||
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 474c7e9dd51a..17d5f539a9aa 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c | |||
@@ -46,6 +46,7 @@ | |||
46 | #include <linux/page-isolation.h> | 46 | #include <linux/page-isolation.h> |
47 | #include <linux/page_cgroup.h> | 47 | #include <linux/page_cgroup.h> |
48 | #include <linux/debugobjects.h> | 48 | #include <linux/debugobjects.h> |
49 | #include <linux/kmemleak.h> | ||
49 | 50 | ||
50 | #include <asm/tlbflush.h> | 51 | #include <asm/tlbflush.h> |
51 | #include <asm/div64.h> | 52 | #include <asm/div64.h> |
@@ -4546,6 +4547,16 @@ void *__init alloc_large_system_hash(const char *tablename, | |||
4546 | if (_hash_mask) | 4547 | if (_hash_mask) |
4547 | *_hash_mask = (1 << log2qty) - 1; | 4548 | *_hash_mask = (1 << log2qty) - 1; |
4548 | 4549 | ||
4550 | /* | ||
4551 | * If hashdist is set, the table allocation is done with __vmalloc() | ||
4552 | * which invokes the kmemleak_alloc() callback. This function may also | ||
4553 | * be called before the slab and kmemleak are initialised when | ||
4554 | * kmemleak simply buffers the request to be executed later | ||
4555 | * (GFP_ATOMIC flag ignored in this case). | ||
4556 | */ | ||
4557 | if (!hashdist) | ||
4558 | kmemleak_alloc(table, size, 1, GFP_ATOMIC); | ||
4559 | |||
4549 | return table; | 4560 | return table; |
4550 | } | 4561 | } |
4551 | 4562 | ||
@@ -107,6 +107,7 @@ | |||
107 | #include <linux/string.h> | 107 | #include <linux/string.h> |
108 | #include <linux/uaccess.h> | 108 | #include <linux/uaccess.h> |
109 | #include <linux/nodemask.h> | 109 | #include <linux/nodemask.h> |
110 | #include <linux/kmemleak.h> | ||
110 | #include <linux/mempolicy.h> | 111 | #include <linux/mempolicy.h> |
111 | #include <linux/mutex.h> | 112 | #include <linux/mutex.h> |
112 | #include <linux/fault-inject.h> | 113 | #include <linux/fault-inject.h> |
@@ -178,13 +179,13 @@ | |||
178 | SLAB_STORE_USER | \ | 179 | SLAB_STORE_USER | \ |
179 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ | 180 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ |
180 | SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ | 181 | SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ |
181 | SLAB_DEBUG_OBJECTS) | 182 | SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE) |
182 | #else | 183 | #else |
183 | # define CREATE_MASK (SLAB_HWCACHE_ALIGN | \ | 184 | # define CREATE_MASK (SLAB_HWCACHE_ALIGN | \ |
184 | SLAB_CACHE_DMA | \ | 185 | SLAB_CACHE_DMA | \ |
185 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ | 186 | SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \ |
186 | SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ | 187 | SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \ |
187 | SLAB_DEBUG_OBJECTS) | 188 | SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE) |
188 | #endif | 189 | #endif |
189 | 190 | ||
190 | /* | 191 | /* |
@@ -964,6 +965,14 @@ static struct array_cache *alloc_arraycache(int node, int entries, | |||
964 | struct array_cache *nc = NULL; | 965 | struct array_cache *nc = NULL; |
965 | 966 | ||
966 | nc = kmalloc_node(memsize, gfp, node); | 967 | nc = kmalloc_node(memsize, gfp, node); |
968 | /* | ||
969 | * The array_cache structures contain pointers to free object. | ||
970 | * However, when such objects are allocated or transfered to another | ||
971 | * cache the pointers are not cleared and they could be counted as | ||
972 | * valid references during a kmemleak scan. Therefore, kmemleak must | ||
973 | * not scan such objects. | ||
974 | */ | ||
975 | kmemleak_no_scan(nc); | ||
967 | if (nc) { | 976 | if (nc) { |
968 | nc->avail = 0; | 977 | nc->avail = 0; |
969 | nc->limit = entries; | 978 | nc->limit = entries; |
@@ -2625,6 +2634,14 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, | |||
2625 | /* Slab management obj is off-slab. */ | 2634 | /* Slab management obj is off-slab. */ |
2626 | slabp = kmem_cache_alloc_node(cachep->slabp_cache, | 2635 | slabp = kmem_cache_alloc_node(cachep->slabp_cache, |
2627 | local_flags, nodeid); | 2636 | local_flags, nodeid); |
2637 | /* | ||
2638 | * If the first object in the slab is leaked (it's allocated | ||
2639 | * but no one has a reference to it), we want to make sure | ||
2640 | * kmemleak does not treat the ->s_mem pointer as a reference | ||
2641 | * to the object. Otherwise we will not report the leak. | ||
2642 | */ | ||
2643 | kmemleak_scan_area(slabp, offsetof(struct slab, list), | ||
2644 | sizeof(struct list_head), local_flags); | ||
2628 | if (!slabp) | 2645 | if (!slabp) |
2629 | return NULL; | 2646 | return NULL; |
2630 | } else { | 2647 | } else { |
@@ -3145,6 +3162,12 @@ static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |||
3145 | STATS_INC_ALLOCMISS(cachep); | 3162 | STATS_INC_ALLOCMISS(cachep); |
3146 | objp = cache_alloc_refill(cachep, flags); | 3163 | objp = cache_alloc_refill(cachep, flags); |
3147 | } | 3164 | } |
3165 | /* | ||
3166 | * To avoid a false negative, if an object that is in one of the | ||
3167 | * per-CPU caches is leaked, we need to make sure kmemleak doesn't | ||
3168 | * treat the array pointers as a reference to the object. | ||
3169 | */ | ||
3170 | kmemleak_erase(&ac->entry[ac->avail]); | ||
3148 | return objp; | 3171 | return objp; |
3149 | } | 3172 | } |
3150 | 3173 | ||
@@ -3364,6 +3387,8 @@ __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, | |||
3364 | out: | 3387 | out: |
3365 | local_irq_restore(save_flags); | 3388 | local_irq_restore(save_flags); |
3366 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); | 3389 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); |
3390 | kmemleak_alloc_recursive(ptr, obj_size(cachep), 1, cachep->flags, | ||
3391 | flags); | ||
3367 | 3392 | ||
3368 | if (unlikely((flags & __GFP_ZERO) && ptr)) | 3393 | if (unlikely((flags & __GFP_ZERO) && ptr)) |
3369 | memset(ptr, 0, obj_size(cachep)); | 3394 | memset(ptr, 0, obj_size(cachep)); |
@@ -3419,6 +3444,8 @@ __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller) | |||
3419 | objp = __do_cache_alloc(cachep, flags); | 3444 | objp = __do_cache_alloc(cachep, flags); |
3420 | local_irq_restore(save_flags); | 3445 | local_irq_restore(save_flags); |
3421 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); | 3446 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); |
3447 | kmemleak_alloc_recursive(objp, obj_size(cachep), 1, cachep->flags, | ||
3448 | flags); | ||
3422 | prefetchw(objp); | 3449 | prefetchw(objp); |
3423 | 3450 | ||
3424 | if (unlikely((flags & __GFP_ZERO) && objp)) | 3451 | if (unlikely((flags & __GFP_ZERO) && objp)) |
@@ -3534,6 +3561,7 @@ static inline void __cache_free(struct kmem_cache *cachep, void *objp) | |||
3534 | struct array_cache *ac = cpu_cache_get(cachep); | 3561 | struct array_cache *ac = cpu_cache_get(cachep); |
3535 | 3562 | ||
3536 | check_irq_off(); | 3563 | check_irq_off(); |
3564 | kmemleak_free_recursive(objp, cachep->flags); | ||
3537 | objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); | 3565 | objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0)); |
3538 | 3566 | ||
3539 | /* | 3567 | /* |
@@ -67,6 +67,7 @@ | |||
67 | #include <linux/rcupdate.h> | 67 | #include <linux/rcupdate.h> |
68 | #include <linux/list.h> | 68 | #include <linux/list.h> |
69 | #include <linux/kmemtrace.h> | 69 | #include <linux/kmemtrace.h> |
70 | #include <linux/kmemleak.h> | ||
70 | #include <asm/atomic.h> | 71 | #include <asm/atomic.h> |
71 | 72 | ||
72 | /* | 73 | /* |
@@ -509,6 +510,7 @@ void *__kmalloc_node(size_t size, gfp_t gfp, int node) | |||
509 | size, PAGE_SIZE << order, gfp, node); | 510 | size, PAGE_SIZE << order, gfp, node); |
510 | } | 511 | } |
511 | 512 | ||
513 | kmemleak_alloc(ret, size, 1, gfp); | ||
512 | return ret; | 514 | return ret; |
513 | } | 515 | } |
514 | EXPORT_SYMBOL(__kmalloc_node); | 516 | EXPORT_SYMBOL(__kmalloc_node); |
@@ -521,6 +523,7 @@ void kfree(const void *block) | |||
521 | 523 | ||
522 | if (unlikely(ZERO_OR_NULL_PTR(block))) | 524 | if (unlikely(ZERO_OR_NULL_PTR(block))) |
523 | return; | 525 | return; |
526 | kmemleak_free(block); | ||
524 | 527 | ||
525 | sp = slob_page(block); | 528 | sp = slob_page(block); |
526 | if (is_slob_page(sp)) { | 529 | if (is_slob_page(sp)) { |
@@ -584,12 +587,14 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size, | |||
584 | } else if (flags & SLAB_PANIC) | 587 | } else if (flags & SLAB_PANIC) |
585 | panic("Cannot create slab cache %s\n", name); | 588 | panic("Cannot create slab cache %s\n", name); |
586 | 589 | ||
590 | kmemleak_alloc(c, sizeof(struct kmem_cache), 1, GFP_KERNEL); | ||
587 | return c; | 591 | return c; |
588 | } | 592 | } |
589 | EXPORT_SYMBOL(kmem_cache_create); | 593 | EXPORT_SYMBOL(kmem_cache_create); |
590 | 594 | ||
591 | void kmem_cache_destroy(struct kmem_cache *c) | 595 | void kmem_cache_destroy(struct kmem_cache *c) |
592 | { | 596 | { |
597 | kmemleak_free(c); | ||
593 | slob_free(c, sizeof(struct kmem_cache)); | 598 | slob_free(c, sizeof(struct kmem_cache)); |
594 | } | 599 | } |
595 | EXPORT_SYMBOL(kmem_cache_destroy); | 600 | EXPORT_SYMBOL(kmem_cache_destroy); |
@@ -613,6 +618,7 @@ void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node) | |||
613 | if (c->ctor) | 618 | if (c->ctor) |
614 | c->ctor(b); | 619 | c->ctor(b); |
615 | 620 | ||
621 | kmemleak_alloc_recursive(b, c->size, 1, c->flags, flags); | ||
616 | return b; | 622 | return b; |
617 | } | 623 | } |
618 | EXPORT_SYMBOL(kmem_cache_alloc_node); | 624 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
@@ -635,6 +641,7 @@ static void kmem_rcu_free(struct rcu_head *head) | |||
635 | 641 | ||
636 | void kmem_cache_free(struct kmem_cache *c, void *b) | 642 | void kmem_cache_free(struct kmem_cache *c, void *b) |
637 | { | 643 | { |
644 | kmemleak_free_recursive(b, c->flags); | ||
638 | if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) { | 645 | if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) { |
639 | struct slob_rcu *slob_rcu; | 646 | struct slob_rcu *slob_rcu; |
640 | slob_rcu = b + (c->size - sizeof(struct slob_rcu)); | 647 | slob_rcu = b + (c->size - sizeof(struct slob_rcu)); |
@@ -20,6 +20,7 @@ | |||
20 | #include <linux/kmemtrace.h> | 20 | #include <linux/kmemtrace.h> |
21 | #include <linux/cpu.h> | 21 | #include <linux/cpu.h> |
22 | #include <linux/cpuset.h> | 22 | #include <linux/cpuset.h> |
23 | #include <linux/kmemleak.h> | ||
23 | #include <linux/mempolicy.h> | 24 | #include <linux/mempolicy.h> |
24 | #include <linux/ctype.h> | 25 | #include <linux/ctype.h> |
25 | #include <linux/debugobjects.h> | 26 | #include <linux/debugobjects.h> |
@@ -143,7 +144,7 @@ | |||
143 | * Set of flags that will prevent slab merging | 144 | * Set of flags that will prevent slab merging |
144 | */ | 145 | */ |
145 | #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ | 146 | #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ |
146 | SLAB_TRACE | SLAB_DESTROY_BY_RCU) | 147 | SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE) |
147 | 148 | ||
148 | #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \ | 149 | #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \ |
149 | SLAB_CACHE_DMA) | 150 | SLAB_CACHE_DMA) |
@@ -1617,6 +1618,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s, | |||
1617 | if (unlikely((gfpflags & __GFP_ZERO) && object)) | 1618 | if (unlikely((gfpflags & __GFP_ZERO) && object)) |
1618 | memset(object, 0, objsize); | 1619 | memset(object, 0, objsize); |
1619 | 1620 | ||
1621 | kmemleak_alloc_recursive(object, objsize, 1, s->flags, gfpflags); | ||
1620 | return object; | 1622 | return object; |
1621 | } | 1623 | } |
1622 | 1624 | ||
@@ -1746,6 +1748,7 @@ static __always_inline void slab_free(struct kmem_cache *s, | |||
1746 | struct kmem_cache_cpu *c; | 1748 | struct kmem_cache_cpu *c; |
1747 | unsigned long flags; | 1749 | unsigned long flags; |
1748 | 1750 | ||
1751 | kmemleak_free_recursive(x, s->flags); | ||
1749 | local_irq_save(flags); | 1752 | local_irq_save(flags); |
1750 | c = get_cpu_slab(s, smp_processor_id()); | 1753 | c = get_cpu_slab(s, smp_processor_id()); |
1751 | debug_check_no_locks_freed(object, c->objsize); | 1754 | debug_check_no_locks_freed(object, c->objsize); |
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 323513858c20..f8189a4b3e13 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c | |||
@@ -24,6 +24,7 @@ | |||
24 | #include <linux/radix-tree.h> | 24 | #include <linux/radix-tree.h> |
25 | #include <linux/rcupdate.h> | 25 | #include <linux/rcupdate.h> |
26 | #include <linux/pfn.h> | 26 | #include <linux/pfn.h> |
27 | #include <linux/kmemleak.h> | ||
27 | 28 | ||
28 | #include <asm/atomic.h> | 29 | #include <asm/atomic.h> |
29 | #include <asm/uaccess.h> | 30 | #include <asm/uaccess.h> |
@@ -1326,6 +1327,9 @@ static void __vunmap(const void *addr, int deallocate_pages) | |||
1326 | void vfree(const void *addr) | 1327 | void vfree(const void *addr) |
1327 | { | 1328 | { |
1328 | BUG_ON(in_interrupt()); | 1329 | BUG_ON(in_interrupt()); |
1330 | |||
1331 | kmemleak_free(addr); | ||
1332 | |||
1329 | __vunmap(addr, 1); | 1333 | __vunmap(addr, 1); |
1330 | } | 1334 | } |
1331 | EXPORT_SYMBOL(vfree); | 1335 | EXPORT_SYMBOL(vfree); |
@@ -1438,8 +1442,17 @@ fail: | |||
1438 | 1442 | ||
1439 | void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot) | 1443 | void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot) |
1440 | { | 1444 | { |
1441 | return __vmalloc_area_node(area, gfp_mask, prot, -1, | 1445 | void *addr = __vmalloc_area_node(area, gfp_mask, prot, -1, |
1442 | __builtin_return_address(0)); | 1446 | __builtin_return_address(0)); |
1447 | |||
1448 | /* | ||
1449 | * A ref_count = 3 is needed because the vm_struct and vmap_area | ||
1450 | * structures allocated in the __get_vm_area_node() function contain | ||
1451 | * references to the virtual address of the vmalloc'ed block. | ||
1452 | */ | ||
1453 | kmemleak_alloc(addr, area->size - PAGE_SIZE, 3, gfp_mask); | ||
1454 | |||
1455 | return addr; | ||
1443 | } | 1456 | } |
1444 | 1457 | ||
1445 | /** | 1458 | /** |
@@ -1458,6 +1471,8 @@ static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot, | |||
1458 | int node, void *caller) | 1471 | int node, void *caller) |
1459 | { | 1472 | { |
1460 | struct vm_struct *area; | 1473 | struct vm_struct *area; |
1474 | void *addr; | ||
1475 | unsigned long real_size = size; | ||
1461 | 1476 | ||
1462 | size = PAGE_ALIGN(size); | 1477 | size = PAGE_ALIGN(size); |
1463 | if (!size || (size >> PAGE_SHIFT) > num_physpages) | 1478 | if (!size || (size >> PAGE_SHIFT) > num_physpages) |
@@ -1469,7 +1484,16 @@ static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot, | |||
1469 | if (!area) | 1484 | if (!area) |
1470 | return NULL; | 1485 | return NULL; |
1471 | 1486 | ||
1472 | return __vmalloc_area_node(area, gfp_mask, prot, node, caller); | 1487 | addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller); |
1488 | |||
1489 | /* | ||
1490 | * A ref_count = 3 is needed because the vm_struct and vmap_area | ||
1491 | * structures allocated in the __get_vm_area_node() function contain | ||
1492 | * references to the virtual address of the vmalloc'ed block. | ||
1493 | */ | ||
1494 | kmemleak_alloc(addr, real_size, 3, gfp_mask); | ||
1495 | |||
1496 | return addr; | ||
1473 | } | 1497 | } |
1474 | 1498 | ||
1475 | void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) | 1499 | void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) |