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-rw-r--r--kernel/lockdep.c229
-rw-r--r--kernel/lockdep_internals.h3
-rw-r--r--kernel/lockdep_proc.c6
3 files changed, 222 insertions, 16 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 06b0c3568f0..977f940fd56 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -310,12 +310,14 @@ EXPORT_SYMBOL(lockdep_on);
#if VERBOSE
# define HARDIRQ_VERBOSE 1
# define SOFTIRQ_VERBOSE 1
+# define RECLAIM_VERBOSE 1
#else
# define HARDIRQ_VERBOSE 0
# define SOFTIRQ_VERBOSE 0
+# define RECLAIM_VERBOSE 0
#endif
-#if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE
+#if VERBOSE || HARDIRQ_VERBOSE || SOFTIRQ_VERBOSE || RECLAIM_VERBOSE
/*
* Quick filtering for interesting events:
*/
@@ -454,6 +456,10 @@ static const char *usage_str[] =
[LOCK_USED_IN_SOFTIRQ_READ] = "in-softirq-R",
[LOCK_ENABLED_SOFTIRQS_READ] = "softirq-on-R",
[LOCK_ENABLED_HARDIRQS_READ] = "hardirq-on-R",
+ [LOCK_USED_IN_RECLAIM_FS] = "in-reclaim-W",
+ [LOCK_USED_IN_RECLAIM_FS_READ] = "in-reclaim-R",
+ [LOCK_HELD_OVER_RECLAIM_FS] = "ov-reclaim-W",
+ [LOCK_HELD_OVER_RECLAIM_FS_READ] = "ov-reclaim-R",
};
const char * __get_key_name(struct lockdep_subclass_key *key, char *str)
@@ -462,9 +468,10 @@ const char * __get_key_name(struct lockdep_subclass_key *key, char *str)
}
void
-get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4)
+get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3,
+ char *c4, char *c5, char *c6)
{
- *c1 = '.', *c2 = '.', *c3 = '.', *c4 = '.';
+ *c1 = '.', *c2 = '.', *c3 = '.', *c4 = '.', *c5 = '.', *c6 = '.';
if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
*c1 = '+';
@@ -493,14 +500,29 @@ get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4
if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
*c4 = '?';
}
+
+ if (class->usage_mask & LOCKF_USED_IN_RECLAIM_FS)
+ *c5 = '+';
+ else
+ if (class->usage_mask & LOCKF_HELD_OVER_RECLAIM_FS)
+ *c5 = '-';
+
+ if (class->usage_mask & LOCKF_HELD_OVER_RECLAIM_FS_READ)
+ *c6 = '-';
+ if (class->usage_mask & LOCKF_USED_IN_RECLAIM_FS_READ) {
+ *c6 = '+';
+ if (class->usage_mask & LOCKF_HELD_OVER_RECLAIM_FS_READ)
+ *c6 = '?';
+ }
+
}
static void print_lock_name(struct lock_class *class)
{
- char str[KSYM_NAME_LEN], c1, c2, c3, c4;
+ char str[KSYM_NAME_LEN], c1, c2, c3, c4, c5, c6;
const char *name;
- get_usage_chars(class, &c1, &c2, &c3, &c4);
+ get_usage_chars(class, &c1, &c2, &c3, &c4, &c5, &c6);
name = class->name;
if (!name) {
@@ -513,7 +535,7 @@ static void print_lock_name(struct lock_class *class)
if (class->subclass)
printk("/%d", class->subclass);
}
- printk("){%c%c%c%c}", c1, c2, c3, c4);
+ printk("){%c%c%c%c%c%c}", c1, c2, c3, c4, c5, c6);
}
static void print_lockdep_cache(struct lockdep_map *lock)
@@ -1306,6 +1328,26 @@ check_prev_add_irq(struct task_struct *curr, struct held_lock *prev,
LOCK_ENABLED_SOFTIRQS, "soft"))
return 0;
+ /*
+ * Prove that the new dependency does not connect a reclaim-fs-safe
+ * lock with a reclaim-fs-unsafe lock - to achieve this we search
+ * the backwards-subgraph starting at <prev>, and the
+ * forwards-subgraph starting at <next>:
+ */
+ if (!check_usage(curr, prev, next, LOCK_USED_IN_RECLAIM_FS,
+ LOCK_HELD_OVER_RECLAIM_FS, "reclaim-fs"))
+ return 0;
+
+ /*
+ * Prove that the new dependency does not connect a reclaim-fs-safe-read
+ * lock with a reclaim-fs-unsafe lock - to achieve this we search
+ * the backwards-subgraph starting at <prev>, and the
+ * forwards-subgraph starting at <next>:
+ */
+ if (!check_usage(curr, prev, next, LOCK_USED_IN_RECLAIM_FS_READ,
+ LOCK_HELD_OVER_RECLAIM_FS, "reclaim-fs-read"))
+ return 0;
+
return 1;
}
@@ -1949,6 +1991,14 @@ static int softirq_verbose(struct lock_class *class)
return 0;
}
+static int reclaim_verbose(struct lock_class *class)
+{
+#if RECLAIM_VERBOSE
+ return class_filter(class);
+#endif
+ return 0;
+}
+
#define STRICT_READ_CHECKS 1
static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
@@ -2007,6 +2057,31 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
if (softirq_verbose(hlock_class(this)))
ret = 2;
break;
+ case LOCK_USED_IN_RECLAIM_FS:
+ if (!valid_state(curr, this, new_bit, LOCK_HELD_OVER_RECLAIM_FS))
+ return 0;
+ if (!valid_state(curr, this, new_bit,
+ LOCK_HELD_OVER_RECLAIM_FS_READ))
+ return 0;
+ /*
+ * just marked it reclaim-fs-safe, check that this lock
+ * took no reclaim-fs-unsafe lock in the past:
+ */
+ if (!check_usage_forwards(curr, this,
+ LOCK_HELD_OVER_RECLAIM_FS, "reclaim-fs"))
+ return 0;
+#if STRICT_READ_CHECKS
+ /*
+ * just marked it reclaim-fs-safe, check that this lock
+ * took no reclaim-fs-unsafe-read lock in the past:
+ */
+ if (!check_usage_forwards(curr, this,
+ LOCK_HELD_OVER_RECLAIM_FS_READ, "reclaim-fs-read"))
+ return 0;
+#endif
+ if (reclaim_verbose(hlock_class(this)))
+ ret = 2;
+ break;
case LOCK_USED_IN_HARDIRQ_READ:
if (!valid_state(curr, this, new_bit, LOCK_ENABLED_HARDIRQS))
return 0;
@@ -2033,6 +2108,19 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
if (softirq_verbose(hlock_class(this)))
ret = 2;
break;
+ case LOCK_USED_IN_RECLAIM_FS_READ:
+ if (!valid_state(curr, this, new_bit, LOCK_HELD_OVER_RECLAIM_FS))
+ return 0;
+ /*
+ * just marked it reclaim-fs-read-safe, check that this lock
+ * took no reclaim-fs-unsafe lock in the past:
+ */
+ if (!check_usage_forwards(curr, this,
+ LOCK_HELD_OVER_RECLAIM_FS, "reclaim-fs"))
+ return 0;
+ if (reclaim_verbose(hlock_class(this)))
+ ret = 2;
+ break;
case LOCK_ENABLED_HARDIRQS:
if (!valid_state(curr, this, new_bit, LOCK_USED_IN_HARDIRQ))
return 0;
@@ -2085,6 +2173,32 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
if (softirq_verbose(hlock_class(this)))
ret = 2;
break;
+ case LOCK_HELD_OVER_RECLAIM_FS:
+ if (!valid_state(curr, this, new_bit, LOCK_USED_IN_RECLAIM_FS))
+ return 0;
+ if (!valid_state(curr, this, new_bit,
+ LOCK_USED_IN_RECLAIM_FS_READ))
+ return 0;
+ /*
+ * just marked it reclaim-fs-unsafe, check that no reclaim-fs-safe
+ * lock in the system ever took it in the past:
+ */
+ if (!check_usage_backwards(curr, this,
+ LOCK_USED_IN_RECLAIM_FS, "reclaim-fs"))
+ return 0;
+#if STRICT_READ_CHECKS
+ /*
+ * just marked it softirq-unsafe, check that no
+ * softirq-safe-read lock in the system ever took
+ * it in the past:
+ */
+ if (!check_usage_backwards(curr, this,
+ LOCK_USED_IN_RECLAIM_FS_READ, "reclaim-fs-read"))
+ return 0;
+#endif
+ if (reclaim_verbose(hlock_class(this)))
+ ret = 2;
+ break;
case LOCK_ENABLED_HARDIRQS_READ:
if (!valid_state(curr, this, new_bit, LOCK_USED_IN_HARDIRQ))
return 0;
@@ -2115,6 +2229,21 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
if (softirq_verbose(hlock_class(this)))
ret = 2;
break;
+ case LOCK_HELD_OVER_RECLAIM_FS_READ:
+ if (!valid_state(curr, this, new_bit, LOCK_USED_IN_RECLAIM_FS))
+ return 0;
+#if STRICT_READ_CHECKS
+ /*
+ * just marked it reclaim-fs-read-unsafe, check that no
+ * reclaim-fs-safe lock in the system ever took it in the past:
+ */
+ if (!check_usage_backwards(curr, this,
+ LOCK_USED_IN_RECLAIM_FS, "reclaim-fs"))
+ return 0;
+#endif
+ if (reclaim_verbose(hlock_class(this)))
+ ret = 2;
+ break;
default:
WARN_ON(1);
break;
@@ -2123,11 +2252,17 @@ static int mark_lock_irq(struct task_struct *curr, struct held_lock *this,
return ret;
}
+enum mark_type {
+ HARDIRQ,
+ SOFTIRQ,
+ RECLAIM_FS,
+};
+
/*
* Mark all held locks with a usage bit:
*/
static int
-mark_held_locks(struct task_struct *curr, int hardirq)
+mark_held_locks(struct task_struct *curr, enum mark_type mark)
{
enum lock_usage_bit usage_bit;
struct held_lock *hlock;
@@ -2136,17 +2271,32 @@ mark_held_locks(struct task_struct *curr, int hardirq)
for (i = 0; i < curr->lockdep_depth; i++) {
hlock = curr->held_locks + i;
- if (hardirq) {
+ switch (mark) {
+ case HARDIRQ:
if (hlock->read)
usage_bit = LOCK_ENABLED_HARDIRQS_READ;
else
usage_bit = LOCK_ENABLED_HARDIRQS;
- } else {
+ break;
+
+ case SOFTIRQ:
if (hlock->read)
usage_bit = LOCK_ENABLED_SOFTIRQS_READ;
else
usage_bit = LOCK_ENABLED_SOFTIRQS;
+ break;
+
+ case RECLAIM_FS:
+ if (hlock->read)
+ usage_bit = LOCK_HELD_OVER_RECLAIM_FS_READ;
+ else
+ usage_bit = LOCK_HELD_OVER_RECLAIM_FS;
+ break;
+
+ default:
+ BUG();
}
+
if (!mark_lock(curr, hlock, usage_bit))
return 0;
}
@@ -2200,7 +2350,7 @@ void trace_hardirqs_on_caller(unsigned long ip)
* We are going to turn hardirqs on, so set the
* usage bit for all held locks:
*/
- if (!mark_held_locks(curr, 1))
+ if (!mark_held_locks(curr, HARDIRQ))
return;
/*
* If we have softirqs enabled, then set the usage
@@ -2208,7 +2358,7 @@ void trace_hardirqs_on_caller(unsigned long ip)
* this bit from being set before)
*/
if (curr->softirqs_enabled)
- if (!mark_held_locks(curr, 0))
+ if (!mark_held_locks(curr, SOFTIRQ))
return;
curr->hardirq_enable_ip = ip;
@@ -2288,7 +2438,7 @@ void trace_softirqs_on(unsigned long ip)
* enabled too:
*/
if (curr->hardirqs_enabled)
- mark_held_locks(curr, 0);
+ mark_held_locks(curr, SOFTIRQ);
}
/*
@@ -2317,6 +2467,31 @@ void trace_softirqs_off(unsigned long ip)
debug_atomic_inc(&redundant_softirqs_off);
}
+void lockdep_trace_alloc(gfp_t gfp_mask)
+{
+ struct task_struct *curr = current;
+
+ if (unlikely(!debug_locks))
+ return;
+
+ /* no reclaim without waiting on it */
+ if (!(gfp_mask & __GFP_WAIT))
+ return;
+
+ /* this guy won't enter reclaim */
+ if ((curr->flags & PF_MEMALLOC) && !(gfp_mask & __GFP_NOMEMALLOC))
+ return;
+
+ /* We're only interested __GFP_FS allocations for now */
+ if (!(gfp_mask & __GFP_FS))
+ return;
+
+ if (DEBUG_LOCKS_WARN_ON(irqs_disabled()))
+ return;
+
+ mark_held_locks(curr, RECLAIM_FS);
+}
+
static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock)
{
/*
@@ -2362,6 +2537,22 @@ static int mark_irqflags(struct task_struct *curr, struct held_lock *hlock)
}
}
+ /*
+ * We reuse the irq context infrastructure more broadly as a general
+ * context checking code. This tests GFP_FS recursion (a lock taken
+ * during reclaim for a GFP_FS allocation is held over a GFP_FS
+ * allocation).
+ */
+ if (!hlock->trylock && (curr->lockdep_reclaim_gfp & __GFP_FS)) {
+ if (hlock->read) {
+ if (!mark_lock(curr, hlock, LOCK_USED_IN_RECLAIM_FS_READ))
+ return 0;
+ } else {
+ if (!mark_lock(curr, hlock, LOCK_USED_IN_RECLAIM_FS))
+ return 0;
+ }
+ }
+
return 1;
}
@@ -2453,6 +2644,10 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
case LOCK_ENABLED_SOFTIRQS:
case LOCK_ENABLED_HARDIRQS_READ:
case LOCK_ENABLED_SOFTIRQS_READ:
+ case LOCK_USED_IN_RECLAIM_FS:
+ case LOCK_USED_IN_RECLAIM_FS_READ:
+ case LOCK_HELD_OVER_RECLAIM_FS:
+ case LOCK_HELD_OVER_RECLAIM_FS_READ:
ret = mark_lock_irq(curr, this, new_bit);
if (!ret)
return 0;
@@ -2966,6 +3161,16 @@ void lock_release(struct lockdep_map *lock, int nested,
}
EXPORT_SYMBOL_GPL(lock_release);
+void lockdep_set_current_reclaim_state(gfp_t gfp_mask)
+{
+ current->lockdep_reclaim_gfp = gfp_mask;
+}
+
+void lockdep_clear_current_reclaim_state(void)
+{
+ current->lockdep_reclaim_gfp = 0;
+}
+
#ifdef CONFIG_LOCK_STAT
static int
print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock,
diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h
index 56b196932c0..e887b783244 100644
--- a/kernel/lockdep_internals.h
+++ b/kernel/lockdep_internals.h
@@ -32,7 +32,8 @@ extern struct list_head all_lock_classes;
extern struct lock_chain lock_chains[];
extern void
-get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3, char *c4);
+get_usage_chars(struct lock_class *class, char *c1, char *c2, char *c3,
+ char *c4, char *c5, char *c6);
extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str);
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index 13716b81389..b84a1dfa907 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)
{
struct lock_class *class = v;
struct lock_list *entry;
- char c1, c2, c3, c4;
+ char c1, c2, c3, c4, c5, c6;
if (v == SEQ_START_TOKEN) {
seq_printf(m, "all lock classes:\n");
@@ -100,8 +100,8 @@ static int l_show(struct seq_file *m, void *v)
seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class));
#endif
- get_usage_chars(class, &c1, &c2, &c3, &c4);
- seq_printf(m, " %c%c%c%c", c1, c2, c3, c4);
+ get_usage_chars(class, &c1, &c2, &c3, &c4, &c5, &c6);
+ seq_printf(m, " %c%c%c%c%c%c", c1, c2, c3, c4, c5, c6);
seq_printf(m, ": ");
print_name(m, class);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-21 22:35:18 +0000