diff options
-rw-r--r-- | Documentation/lockdep-design.txt | 30 | ||||
-rw-r--r-- | kernel/lockdep.c | 24 | ||||
-rw-r--r-- | kernel/lockdep_internals.h | 7 | ||||
-rw-r--r-- | kernel/lockdep_proc.c | 6 |
4 files changed, 36 insertions, 31 deletions
diff --git a/Documentation/lockdep-design.txt b/Documentation/lockdep-design.txt index 488773018152..938ea22f2cc0 100644 --- a/Documentation/lockdep-design.txt +++ b/Documentation/lockdep-design.txt | |||
@@ -27,33 +27,37 @@ lock-class. | |||
27 | State | 27 | State |
28 | ----- | 28 | ----- |
29 | 29 | ||
30 | The validator tracks lock-class usage history into 5 separate state bits: | 30 | The validator tracks lock-class usage history into 4n + 1 separate state bits: |
31 | 31 | ||
32 | - 'ever held in hardirq context' [ == hardirq-safe ] | 32 | - 'ever held in STATE context' |
33 | - 'ever held in softirq context' [ == softirq-safe ] | 33 | - 'ever head as readlock in STATE context' |
34 | - 'ever held with hardirqs enabled' [ == hardirq-unsafe ] | 34 | - 'ever head with STATE enabled' |
35 | - 'ever held with softirqs and hardirqs enabled' [ == softirq-unsafe ] | 35 | - 'ever head as readlock with STATE enabled' |
36 | |||
37 | Where STATE can be either one of (kernel/lockdep_states.h) | ||
38 | - hardirq | ||
39 | - softirq | ||
40 | - reclaim_fs | ||
36 | 41 | ||
37 | - 'ever used' [ == !unused ] | 42 | - 'ever used' [ == !unused ] |
38 | 43 | ||
39 | When locking rules are violated, these 4 state bits are presented in the | 44 | When locking rules are violated, these state bits are presented in the |
40 | locking error messages, inside curlies. A contrived example: | 45 | locking error messages, inside curlies. A contrived example: |
41 | 46 | ||
42 | modprobe/2287 is trying to acquire lock: | 47 | modprobe/2287 is trying to acquire lock: |
43 | (&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24 | 48 | (&sio_locks[i].lock){-.-...}, at: [<c02867fd>] mutex_lock+0x21/0x24 |
44 | 49 | ||
45 | but task is already holding lock: | 50 | but task is already holding lock: |
46 | (&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24 | 51 | (&sio_locks[i].lock){-.-...}, at: [<c02867fd>] mutex_lock+0x21/0x24 |
47 | 52 | ||
48 | 53 | ||
49 | The bit position indicates hardirq, softirq, hardirq-read, | 54 | The bit position indicates STATE, STATE-read, for each of the states listed |
50 | softirq-read respectively, and the character displayed in each | 55 | above, and the character displayed in each indicates: |
51 | indicates: | ||
52 | 56 | ||
53 | '.' acquired while irqs disabled | 57 | '.' acquired while irqs disabled |
54 | '+' acquired in irq context | 58 | '+' acquired in irq context |
55 | '-' acquired with irqs enabled | 59 | '-' acquired with irqs enabled |
56 | '?' read acquired in irq context with irqs enabled. | 60 | '?' acquired in irq context with irqs enabled. |
57 | 61 | ||
58 | Unused mutexes cannot be part of the cause of an error. | 62 | Unused mutexes cannot be part of the cause of an error. |
59 | 63 | ||
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 1b4ee3c0b789..22ced8d4912f 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c | |||
@@ -487,25 +487,25 @@ static char get_usage_char(struct lock_class *class, enum lock_usage_bit bit) | |||
487 | return c; | 487 | return c; |
488 | } | 488 | } |
489 | 489 | ||
490 | void | 490 | void get_usage_chars(struct lock_class *class, char usage[LOCK_USAGE_CHARS]) |
491 | get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, | ||
492 | char *c4, char *c5, char *c6) | ||
493 | { | 491 | { |
494 | *c1 = get_usage_char(class, LOCK_USED_IN_HARDIRQ); | 492 | int i = 0; |
495 | *c2 = get_usage_char(class, LOCK_USED_IN_SOFTITQ); | ||
496 | *c3 = get_usage_char(class, LOCK_USED_IN_HARDIRQ_READ); | ||
497 | *c4 = get_usage_char(class, LOCK_USED_IN_SOFTITQ_READ); | ||
498 | 493 | ||
499 | *c5 = get_usage_char(class, LOCK_USED_IN_RECLAIM_FS); | 494 | #define LOCKDEP_STATE(__STATE) \ |
500 | *c6 = get_usage_char(class, LOCK_USED_IN_RECLAIM_FS_READ); | 495 | usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE); \ |
496 | usage[i++] = get_usage_char(class, LOCK_USED_IN_##__STATE##_READ); | ||
497 | #include "lockdep_states.h" | ||
498 | #undef LOCKDEP_STATE | ||
499 | |||
500 | usage[i] = '\0'; | ||
501 | } | 501 | } |
502 | 502 | ||
503 | static void print_lock_name(struct lock_class *class) | 503 | static void print_lock_name(struct lock_class *class) |
504 | { | 504 | { |
505 | char str[KSYM_NAME_LEN], c1, c2, c3, c4, c5, c6; | 505 | char str[KSYM_NAME_LEN], usage[LOCK_USAGE_CHARS]; |
506 | const char *name; | 506 | const char *name; |
507 | 507 | ||
508 | get_usage_chars(class, &c1, &c2, &c3, &c4, &c5, &c6); | 508 | get_usage_chars(class, usage); |
509 | 509 | ||
510 | name = class->name; | 510 | name = class->name; |
511 | if (!name) { | 511 | if (!name) { |
@@ -518,7 +518,7 @@ static void print_lock_name(struct lock_class *class) | |||
518 | if (class->subclass) | 518 | if (class->subclass) |
519 | printk("/%d", class->subclass); | 519 | printk("/%d", class->subclass); |
520 | } | 520 | } |
521 | printk("){%c%c%c%c%c%c}", c1, c2, c3, c4, c5, c6); | 521 | printk("){%s}", usage); |
522 | } | 522 | } |
523 | 523 | ||
524 | static void print_lockdep_cache(struct lockdep_map *lock) | 524 | static void print_lockdep_cache(struct lockdep_map *lock) |
diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h index 7e653e66ce5a..a2cc7e9a6e84 100644 --- a/kernel/lockdep_internals.h +++ b/kernel/lockdep_internals.h | |||
@@ -70,9 +70,10 @@ enum { | |||
70 | extern struct list_head all_lock_classes; | 70 | extern struct list_head all_lock_classes; |
71 | extern struct lock_chain lock_chains[]; | 71 | extern struct lock_chain lock_chains[]; |
72 | 72 | ||
73 | extern void | 73 | #define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2) |
74 | get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, | 74 | |
75 | char *c4, char *c5, char *c6); | 75 | extern void get_usage_chars(struct lock_class *class, |
76 | char usage[LOCK_USAGE_CHARS]); | ||
76 | 77 | ||
77 | extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str); | 78 | extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str); |
78 | 79 | ||
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c index bd474fd9df9d..b51064ce564a 100644 --- a/kernel/lockdep_proc.c +++ b/kernel/lockdep_proc.c | |||
@@ -84,7 +84,7 @@ static int l_show(struct seq_file *m, void *v) | |||
84 | { | 84 | { |
85 | struct lock_class *class = v; | 85 | struct lock_class *class = v; |
86 | struct lock_list *entry; | 86 | struct lock_list *entry; |
87 | char c1, c2, c3, c4, c5, c6; | 87 | char usage[LOCK_USAGE_CHARS]; |
88 | 88 | ||
89 | if (v == SEQ_START_TOKEN) { | 89 | if (v == SEQ_START_TOKEN) { |
90 | seq_printf(m, "all lock classes:\n"); | 90 | seq_printf(m, "all lock classes:\n"); |
@@ -100,8 +100,8 @@ static int l_show(struct seq_file *m, void *v) | |||
100 | seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class)); | 100 | seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class)); |
101 | #endif | 101 | #endif |
102 | 102 | ||
103 | get_usage_chars(class, &c1, &c2, &c3, &c4, &c5, &c6); | 103 | get_usage_chars(class, usage); |
104 | seq_printf(m, " %c%c%c%c%c%c", c1, c2, c3, c4, c5, c6); | 104 | seq_printf(m, " %s", usage); |
105 | 105 | ||
106 | seq_printf(m, ": "); | 106 | seq_printf(m, ": "); |
107 | print_name(m, class); | 107 | print_name(m, class); |