From: Yuyang Du <duyuyang@gmail.com>
To: peterz@infradead.org, will.deacon@arm.com, mingo@kernel.org
Cc: bvanassche@acm.org, ming.lei@redhat.com, frederic@kernel.org,
tglx@linutronix.de, linux-kernel@vger.kernel.org,
Yuyang Du <duyuyang@gmail.com>
Subject: [PATCH 01/28] locking/lockdep: Change all print_*() return type to void
Date: Wed, 24 Apr 2019 18:19:07 +0800 [thread overview]
Message-ID: <20190424101934.51535-2-duyuyang@gmail.com> (raw)
In-Reply-To: <20190424101934.51535-1-duyuyang@gmail.com>
Since none of the print_*() function's return value is necessary, change
their return type to void. No functional change.
In cases where an invariable return value is used, this change slightly
improves readability, i.e.:
print_x();
return 0;
is definitely better than:
return print_x(); /* where print_x() always returns 0 */
Signed-off-by: Yuyang Du <duyuyang@gmail.com>
---
kernel/locking/lockdep.c | 197 ++++++++++++++++++++++++-----------------------
1 file changed, 101 insertions(+), 96 deletions(-)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 147ae0a..4bf396b 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1422,16 +1422,15 @@ static void print_lock_trace(struct lock_trace *trace, unsigned int spaces)
* Print a dependency chain entry (this is only done when a deadlock
* has been detected):
*/
-static noinline int
+static noinline void
print_circular_bug_entry(struct lock_list *target, int depth)
{
if (debug_locks_silent)
- return 0;
+ return;
printk("\n-> #%u", depth);
print_lock_name(target->class);
printk(KERN_CONT ":\n");
print_lock_trace(&target->trace, 6);
- return 0;
}
static void
@@ -1488,7 +1487,7 @@ static void print_lock_trace(struct lock_trace *trace, unsigned int spaces)
* When a circular dependency is detected, print the
* header first:
*/
-static noinline int
+static noinline void
print_circular_bug_header(struct lock_list *entry, unsigned int depth,
struct held_lock *check_src,
struct held_lock *check_tgt)
@@ -1496,7 +1495,7 @@ static void print_lock_trace(struct lock_trace *trace, unsigned int spaces)
struct task_struct *curr = current;
if (debug_locks_silent)
- return 0;
+ return;
pr_warn("\n");
pr_warn("======================================================\n");
@@ -1514,8 +1513,6 @@ static void print_lock_trace(struct lock_trace *trace, unsigned int spaces)
pr_warn("\nthe existing dependency chain (in reverse order) is:\n");
print_circular_bug_entry(entry, depth);
-
- return 0;
}
static inline int class_equal(struct lock_list *entry, void *data)
@@ -1523,7 +1520,7 @@ static inline int class_equal(struct lock_list *entry, void *data)
return entry->class == data;
}
-static noinline int print_circular_bug(struct lock_list *this,
+static noinline void print_circular_bug(struct lock_list *this,
struct lock_list *target,
struct held_lock *check_src,
struct held_lock *check_tgt)
@@ -1534,10 +1531,10 @@ static noinline int print_circular_bug(struct lock_list *this,
int depth;
if (!debug_locks_off_graph_unlock() || debug_locks_silent)
- return 0;
+ return;
if (!save_trace(&this->trace))
- return 0;
+ return;
depth = get_lock_depth(target);
@@ -1559,21 +1556,17 @@ static noinline int print_circular_bug(struct lock_list *this,
printk("\nstack backtrace:\n");
dump_stack();
-
- return 0;
}
-static noinline int print_bfs_bug(int ret)
+static noinline void print_bfs_bug(int ret)
{
if (!debug_locks_off_graph_unlock())
- return 0;
+ return;
/*
* Breadth-first-search failed, graph got corrupted?
*/
WARN(1, "lockdep bfs error:%d\n", ret);
-
- return 0;
}
static int noop_count(struct lock_list *entry, void *data)
@@ -1756,7 +1749,7 @@ static void print_lock_class_header(struct lock_class *class, int depth)
*/
static void __used
print_shortest_lock_dependencies(struct lock_list *leaf,
- struct lock_list *root)
+ struct lock_list *root)
{
struct lock_list *entry = leaf;
int depth;
@@ -1778,8 +1771,6 @@ static void print_lock_class_header(struct lock_class *class, int depth)
entry = get_lock_parent(entry);
depth--;
} while (entry && (depth >= 0));
-
- return;
}
static void
@@ -1838,7 +1829,7 @@ static void print_lock_class_header(struct lock_class *class, int depth)
printk("\n *** DEADLOCK ***\n\n");
}
-static int
+static void
print_bad_irq_dependency(struct task_struct *curr,
struct lock_list *prev_root,
struct lock_list *next_root,
@@ -1851,7 +1842,7 @@ static void print_lock_class_header(struct lock_class *class, int depth)
const char *irqclass)
{
if (!debug_locks_off_graph_unlock() || debug_locks_silent)
- return 0;
+ return;
pr_warn("\n");
pr_warn("=====================================================\n");
@@ -1897,19 +1888,17 @@ static void print_lock_class_header(struct lock_class *class, int depth)
pr_warn("\nthe dependencies between %s-irq-safe lock and the holding lock:\n", irqclass);
if (!save_trace(&prev_root->trace))
- return 0;
+ return;
print_shortest_lock_dependencies(backwards_entry, prev_root);
pr_warn("\nthe dependencies between the lock to be acquired");
pr_warn(" and %s-irq-unsafe lock:\n", irqclass);
if (!save_trace(&next_root->trace))
- return 0;
+ return;
print_shortest_lock_dependencies(forwards_entry, next_root);
pr_warn("\nstack backtrace:\n");
dump_stack();
-
- return 0;
}
static int
@@ -1926,23 +1915,28 @@ static void print_lock_class_header(struct lock_class *class, int depth)
this.class = hlock_class(prev);
ret = find_usage_backwards(&this, lock_flag(bit_backwards), &target_entry);
- if (ret < 0)
- return print_bfs_bug(ret);
+ if (ret < 0) {
+ print_bfs_bug(ret);
+ return 0;
+ }
if (ret == 1)
return ret;
that.parent = NULL;
that.class = hlock_class(next);
ret = find_usage_forwards(&that, lock_flag(bit_forwards), &target_entry1);
- if (ret < 0)
- return print_bfs_bug(ret);
+ if (ret < 0) {
+ print_bfs_bug(ret);
+ return 0;
+ }
if (ret == 1)
return ret;
- return print_bad_irq_dependency(curr, &this, &that,
- target_entry, target_entry1,
- prev, next,
- bit_backwards, bit_forwards, irqclass);
+ print_bad_irq_dependency(curr, &this, &that,
+ target_entry, target_entry1,
+ prev, next,
+ bit_backwards, bit_forwards, irqclass);
+ return 0;
}
static const char *state_names[] = {
@@ -2048,8 +2042,7 @@ static inline void inc_chains(void)
#endif
static void
-print_deadlock_scenario(struct held_lock *nxt,
- struct held_lock *prv)
+print_deadlock_scenario(struct held_lock *nxt, struct held_lock *prv)
{
struct lock_class *next = hlock_class(nxt);
struct lock_class *prev = hlock_class(prv);
@@ -2067,12 +2060,12 @@ static inline void inc_chains(void)
printk(" May be due to missing lock nesting notation\n\n");
}
-static int
+static void
print_deadlock_bug(struct task_struct *curr, struct held_lock *prev,
struct held_lock *next)
{
if (!debug_locks_off_graph_unlock() || debug_locks_silent)
- return 0;
+ return;
pr_warn("\n");
pr_warn("============================================\n");
@@ -2091,8 +2084,6 @@ static inline void inc_chains(void)
pr_warn("\nstack backtrace:\n");
dump_stack();
-
- return 0;
}
/*
@@ -2134,7 +2125,8 @@ static inline void inc_chains(void)
if (nest)
return 2;
- return print_deadlock_bug(curr, prev, next);
+ print_deadlock_bug(curr, prev, next);
+ return 0;
}
return 1;
}
@@ -2201,10 +2193,14 @@ static inline void inc_chains(void)
this.class = hlock_class(next);
this.parent = NULL;
ret = check_noncircular(&this, hlock_class(prev), &target_entry);
- if (unlikely(!ret))
- return print_circular_bug(&this, target_entry, next, prev);
- else if (unlikely(ret < 0))
- return print_bfs_bug(ret);
+ if (unlikely(!ret)) {
+ print_circular_bug(&this, target_entry, next, prev);
+ return 0;
+ }
+ else if (unlikely(ret < 0)) {
+ print_bfs_bug(ret);
+ return 0;
+ }
if (!check_prev_add_irq(curr, prev, next))
return 0;
@@ -2245,8 +2241,10 @@ static inline void inc_chains(void)
debug_atomic_inc(nr_redundant);
return 2;
}
- if (ret < 0)
- return print_bfs_bug(ret);
+ if (ret < 0) {
+ print_bfs_bug(ret);
+ return 0;
+ }
if (!save_trace(&trace))
@@ -2773,8 +2771,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
-static void
-print_usage_bug_scenario(struct held_lock *lock)
+static void print_usage_bug_scenario(struct held_lock *lock)
{
struct lock_class *class = hlock_class(lock);
@@ -2791,12 +2788,12 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
printk("\n *** DEADLOCK ***\n\n");
}
-static int
+static void
print_usage_bug(struct task_struct *curr, struct held_lock *this,
enum lock_usage_bit prev_bit, enum lock_usage_bit new_bit)
{
if (!debug_locks_off_graph_unlock() || debug_locks_silent)
- return 0;
+ return;
pr_warn("\n");
pr_warn("================================\n");
@@ -2826,8 +2823,6 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
pr_warn("\nstack backtrace:\n");
dump_stack();
-
- return 0;
}
/*
@@ -2837,8 +2832,10 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
valid_state(struct task_struct *curr, struct held_lock *this,
enum lock_usage_bit new_bit, enum lock_usage_bit bad_bit)
{
- if (unlikely(hlock_class(this)->usage_mask & (1 << bad_bit)))
- return print_usage_bug(curr, this, bad_bit, new_bit);
+ if (unlikely(hlock_class(this)->usage_mask & (1 << bad_bit))) {
+ print_usage_bug(curr, this, bad_bit, new_bit);
+ return 0;
+ }
return 1;
}
@@ -2846,7 +2843,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
/*
* print irq inversion bug:
*/
-static int
+static void
print_irq_inversion_bug(struct task_struct *curr,
struct lock_list *root, struct lock_list *other,
struct held_lock *this, int forwards,
@@ -2857,7 +2854,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
int depth;
if (!debug_locks_off_graph_unlock() || debug_locks_silent)
- return 0;
+ return;
pr_warn("\n");
pr_warn("========================================================\n");
@@ -2898,13 +2895,11 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
pr_warn("\nthe shortest dependencies between 2nd lock and 1st lock:\n");
if (!save_trace(&root->trace))
- return 0;
+ return;
print_shortest_lock_dependencies(other, root);
pr_warn("\nstack backtrace:\n");
dump_stack();
-
- return 0;
}
/*
@@ -2922,13 +2917,16 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
root.parent = NULL;
root.class = hlock_class(this);
ret = find_usage_forwards(&root, lock_flag(bit), &target_entry);
- if (ret < 0)
- return print_bfs_bug(ret);
+ if (ret < 0) {
+ print_bfs_bug(ret);
+ return 0;
+ }
if (ret == 1)
return ret;
- return print_irq_inversion_bug(curr, &root, target_entry,
- this, 1, irqclass);
+ print_irq_inversion_bug(curr, &root, target_entry,
+ this, 1, irqclass);
+ return 0;
}
/*
@@ -2946,13 +2944,16 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this,
root.parent = NULL;
root.class = hlock_class(this);
ret = find_usage_backwards(&root, lock_flag(bit), &target_entry);
- if (ret < 0)
- return print_bfs_bug(ret);
+ if (ret < 0) {
+ print_bfs_bug(ret);
+ return 0;
+ }
if (ret == 1)
return ret;
- return print_irq_inversion_bug(curr, &root, target_entry,
- this, 0, irqclass);
+ print_irq_inversion_bug(curr, &root, target_entry,
+ this, 0, irqclass);
+ return 0;
}
void print_irqtrace_events(struct task_struct *curr)
@@ -3495,15 +3496,15 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name,
struct lock_class_key __lockdep_no_validate__;
EXPORT_SYMBOL_GPL(__lockdep_no_validate__);
-static int
+static void
print_lock_nested_lock_not_held(struct task_struct *curr,
struct held_lock *hlock,
unsigned long ip)
{
if (!debug_locks_off())
- return 0;
+ return;
if (debug_locks_silent)
- return 0;
+ return;
pr_warn("\n");
pr_warn("==================================\n");
@@ -3525,8 +3526,6 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name,
pr_warn("\nstack backtrace:\n");
dump_stack();
-
- return 0;
}
static int __lock_is_held(const struct lockdep_map *lock, int read);
@@ -3675,8 +3674,10 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
}
chain_key = iterate_chain_key(chain_key, class_idx);
- if (nest_lock && !__lock_is_held(nest_lock, -1))
- return print_lock_nested_lock_not_held(curr, hlock, ip);
+ if (nest_lock && !__lock_is_held(nest_lock, -1)) {
+ print_lock_nested_lock_not_held(curr, hlock, ip);
+ return 0;
+ }
if (!debug_locks_silent) {
WARN_ON_ONCE(depth && !hlock_class(hlock - 1)->key);
@@ -3712,14 +3713,14 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
return 1;
}
-static int
-print_unlock_imbalance_bug(struct task_struct *curr, struct lockdep_map *lock,
- unsigned long ip)
+static void print_unlock_imbalance_bug(struct task_struct *curr,
+ struct lockdep_map *lock,
+ unsigned long ip)
{
if (!debug_locks_off())
- return 0;
+ return;
if (debug_locks_silent)
- return 0;
+ return;
pr_warn("\n");
pr_warn("=====================================\n");
@@ -3737,8 +3738,6 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
pr_warn("\nstack backtrace:\n");
dump_stack();
-
- return 0;
}
static int match_held_lock(const struct held_lock *hlock,
@@ -3857,8 +3856,10 @@ static int reacquire_held_locks(struct task_struct *curr, unsigned int depth,
return 0;
hlock = find_held_lock(curr, lock, depth, &i);
- if (!hlock)
- return print_unlock_imbalance_bug(curr, lock, ip);
+ if (!hlock) {
+ print_unlock_imbalance_bug(curr, lock, ip);
+ return 0;
+ }
lockdep_init_map(lock, name, key, 0);
class = register_lock_class(lock, subclass, 0);
@@ -3898,8 +3899,10 @@ static int __lock_downgrade(struct lockdep_map *lock, unsigned long ip)
return 0;
hlock = find_held_lock(curr, lock, depth, &i);
- if (!hlock)
- return print_unlock_imbalance_bug(curr, lock, ip);
+ if (!hlock) {
+ print_unlock_imbalance_bug(curr, lock, ip);
+ return 0;
+ }
curr->lockdep_depth = i;
curr->curr_chain_key = hlock->prev_chain_key;
@@ -3943,16 +3946,20 @@ static int __lock_downgrade(struct lockdep_map *lock, unsigned long ip)
* So we're all set to release this lock.. wait what lock? We don't
* own any locks, you've been drinking again?
*/
- if (DEBUG_LOCKS_WARN_ON(depth <= 0))
- return print_unlock_imbalance_bug(curr, lock, ip);
+ if (DEBUG_LOCKS_WARN_ON(depth <= 0)) {
+ print_unlock_imbalance_bug(curr, lock, ip);
+ return 0;
+ }
/*
* Check whether the lock exists in the current stack
* of held locks:
*/
hlock = find_held_lock(curr, lock, depth, &i);
- if (!hlock)
- return print_unlock_imbalance_bug(curr, lock, ip);
+ if (!hlock) {
+ print_unlock_imbalance_bug(curr, lock, ip);
+ return 0;
+ }
if (hlock->instance == lock)
lock_release_holdtime(hlock);
@@ -4295,14 +4302,14 @@ void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie cookie)
EXPORT_SYMBOL_GPL(lock_unpin_lock);
#ifdef CONFIG_LOCK_STAT
-static int
-print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock,
- unsigned long ip)
+static void print_lock_contention_bug(struct task_struct *curr,
+ struct lockdep_map *lock,
+ unsigned long ip)
{
if (!debug_locks_off())
- return 0;
+ return;
if (debug_locks_silent)
- return 0;
+ return;
pr_warn("\n");
pr_warn("=================================\n");
@@ -4320,8 +4327,6 @@ void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie cookie)
pr_warn("\nstack backtrace:\n");
dump_stack();
-
- return 0;
}
static void
--
1.8.3.1
next prev parent reply other threads:[~2019-04-24 10:20 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-24 10:19 [PATCH 00/28] Optimize IRQ usage checks and other small bits Yuyang Du
2019-04-24 10:19 ` Yuyang Du [this message]
2019-04-24 10:19 ` [PATCH 02/28] locking/lockdep: Add description and explanation in lockdep design doc Yuyang Du
2019-04-25 14:01 ` Peter Zijlstra
2019-04-26 5:41 ` Yuyang Du
2019-04-24 10:19 ` [PATCH 03/28] locking/lockdep: Adjust lock usage bit character checks Yuyang Du
2019-04-24 10:19 ` [PATCH 04/28] locking/lockdep: Remove useless conditional macro Yuyang Du
2019-04-24 10:19 ` [PATCH 05/28] locking/lockdep: Print the right depth for chain key colission Yuyang Du
2019-04-24 10:19 ` [PATCH 06/28] locking/lockdep: Update obsolete struct field description Yuyang Du
2019-04-24 10:19 ` [PATCH 07/28] locking/lockdep: Use lockdep_init_task for task initiation consistently Yuyang Du
2019-04-24 10:19 ` [PATCH 08/28] locking/lockdep: Define INITIAL_CHAIN_KEY for chain keys to start with Yuyang Du
2019-04-24 10:19 ` [PATCH 09/28] locking/lockdep: Change the range of class_idx in held_lock struct Yuyang Du
2019-04-24 10:19 ` [PATCH 10/28] locking/lockdep: Remove unused argument in validate_chain() and check_deadlock() Yuyang Du
2019-04-24 10:19 ` [PATCH 11/28] locking/lockdep: Update comment Yuyang Du
2019-04-24 10:19 ` [PATCH 12/28] locking/lockdep: Change type of the element field in circular_queue Yuyang Du
2019-04-24 10:19 ` [PATCH 13/28] locking/lockdep: Change the return type of __cq_dequeue() Yuyang Du
2019-04-24 10:19 ` [PATCH 14/28] locking/lockdep: Avoid constant checks in __bfs by using offset reference Yuyang Du
2019-04-24 10:19 ` [PATCH 15/28] locking/lockdep: Update comments on dependency search Yuyang Du
2019-04-24 10:19 ` [PATCH 16/28] locking/lockdep: Add explanation to lock usage rules in lockdep design doc Yuyang Du
2019-04-24 10:19 ` [PATCH 17/28] locking/lockdep: Remove redundant argument in check_deadlock Yuyang Du
2019-04-24 10:19 ` [PATCH 18/28] locking/lockdep: Remove unused argument in __lock_release Yuyang Du
2019-04-24 10:19 ` [PATCH 19/28] locking/lockdep: Optimize irq usage check when marking lock usage bit Yuyang Du
2019-04-25 19:32 ` Peter Zijlstra
2019-04-26 6:57 ` Yuyang Du
2019-04-30 12:11 ` Peter Zijlstra
2019-05-06 3:05 ` Yuyang Du
2019-05-06 3:42 ` Yuyang Du
2019-05-07 1:47 ` Frederic Weisbecker
2019-05-07 2:21 ` Yuyang Du
2019-04-24 10:19 ` [PATCH 20/28] locking/lockdep: Refactorize check_noncircular and check_redundant Yuyang Du
2019-04-25 19:48 ` Peter Zijlstra
2019-04-26 6:48 ` Yuyang Du
2019-04-24 10:19 ` [PATCH 21/28] locking/lockdep: Consolidate lock usage bit initialization Yuyang Du
2019-04-24 10:19 ` [PATCH 22/28] locking/lockdep: Adjust new bit cases in mark_lock Yuyang Du
2019-04-25 19:52 ` Peter Zijlstra
2019-04-26 6:47 ` Yuyang Du
2019-04-24 10:19 ` [PATCH 23/28] locking/lockdep: Update irqsafe lock bitmaps Yuyang Du
2019-04-25 19:55 ` Peter Zijlstra
2019-04-26 6:45 ` Yuyang Du
2019-04-24 10:19 ` [PATCH 24/28] locking/lockdep: Remove !dir in lock irq usage check Yuyang Du
2019-04-25 20:03 ` Peter Zijlstra
2019-04-26 7:06 ` Yuyang Du
2019-04-26 7:25 ` Boqun Feng
2019-04-30 15:35 ` Peter Zijlstra
2019-04-24 10:19 ` [PATCH 25/28] locking/lockdep: Implement new IRQ usage checking algorithm Yuyang Du
2019-04-24 10:19 ` [PATCH 26/28] locking/lockdep: Remove __bfs Yuyang Du
2019-04-25 20:06 ` Peter Zijlstra
2019-04-26 6:35 ` Yuyang Du
2019-04-24 10:19 ` [PATCH 27/28] locking/lockdep: Remove locks_before Yuyang Du
2019-04-24 10:19 ` [PATCH 28/28] locking/lockdep: Reduce lock_list_entries by half Yuyang Du
2019-04-25 18:56 ` [PATCH 00/28] Optimize IRQ usage checks and other small bits Peter Zijlstra
2019-04-26 6:59 ` Yuyang Du
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190424101934.51535-2-duyuyang@gmail.com \
--to=duyuyang@gmail.com \
--cc=bvanassche@acm.org \
--cc=frederic@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ming.lei@redhat.com \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=will.deacon@arm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).