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Merge tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux

Browse Source 
Pull RCU updates from Joel Fernandes:

 - Updates and additions to MAINTAINERS files, with Boqun being added to
   the RCU entry and Zqiang being added as an RCU reviewer.

   I have also transitioned from reviewer to maintainer; however, Paul
   will be taking over sending RCU pull-requests for the next merge
   window.

 - Resolution of hotplug warning in nohz code, achieved by fixing
   cpu_is_hotpluggable() through interaction with the nohz subsystem.

   Tick dependency modifications by Zqiang, focusing on fixing usage of
   the TICK_DEP_BIT_RCU_EXP bitmask.

 - Avoid needless calls to the rcu-lazy shrinker for CONFIG_RCU_LAZY=n
   kernels, fixed by Zqiang.

 - Improvements to rcu-tasks stall reporting by Neeraj.

 - Initial renaming of k[v]free_rcu() to k[v]free_rcu_mightsleep() for
   increased robustness, affecting several components like mac802154,
   drbd, vmw_vmci, tracing, and more.

   A report by Eric Dumazet showed that the API could be unknowingly
   used in an atomic context, so we'd rather make sure they know what
   they're asking for by being explicit:

      https://lore.kernel.org/all/20221202052847.2623997-1-edumazet@google.com/

 - Documentation updates, including corrections to spelling,
   clarifications in comments, and improvements to the srcu_size_state
   comments.

 - Better srcu_struct cache locality for readers, by adjusting the size
   of srcu_struct in support of SRCU usage by Christoph Hellwig.

 - Teach lockdep to detect deadlocks between srcu_read_lock() vs
   synchronize_srcu() contributed by Boqun.

   Previously lockdep could not detect such deadlocks, now it can.

 - Integration of rcutorture and rcu-related tools, targeted for v6.4
   from Boqun's tree, featuring new SRCU deadlock scenarios, test_nmis
   module parameter, and more

 - Miscellaneous changes, various code cleanups and comment improvements

* tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux: (71 commits)
  checkpatch: Error out if deprecated RCU API used
  mac802154: Rename kfree_rcu() to kvfree_rcu_mightsleep()
  rcuscale: Rename kfree_rcu() to kfree_rcu_mightsleep()
  ext4/super: Rename kfree_rcu() to kfree_rcu_mightsleep()
  net/mlx5: Rename kfree_rcu() to kfree_rcu_mightsleep()
  net/sysctl: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  lib/test_vmalloc.c: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  tracing: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  misc: vmw_vmci: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  drbd: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
  rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access
  rcu: Avoid stack overflow due to __rcu_irq_enter_check_tick() being kprobe-ed
  rcu-tasks: Report stalls during synchronize_srcu() in rcu_tasks_postscan()
  rcu: Permit start_poll_synchronize_rcu_expedited() to be invoked early
  rcu: Remove never-set needwake assignment from rcu_report_qs_rdp()
  rcu: Register rcu-lazy shrinker only for CONFIG_RCU_LAZY=y kernels
  rcu: Fix missing TICK_DEP_MASK_RCU_EXP dependency check
  rcu: Fix set/clear TICK_DEP_BIT_RCU_EXP bitmask race
  rcu/trace: use strscpy() to instead of strncpy()
  tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem
  ...
This commit is contained in:
Linus Torvalds
2023-04-24 12:16:14 -07:00
parent 5d77652fbf 8ae9985774
commit 5dfb75e842
61 changed files with 916 additions and 343 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/locking/lockdep.c
+57 -7
View File
@@ -1881,6 +1881,8 @@ print_circular_lock_scenario(struct held_lock *src,
struct lock_class *source = hlock_class(src);
struct lock_class *target = hlock_class(tgt);
struct lock_class *parent = prt->class;
int src_read = src->read;
int tgt_read = tgt->read;
/*
* A direct locking problem where unsafe_class lock is taken
@@ -1908,7 +1910,10 @@ print_circular_lock_scenario(struct held_lock *src,
printk(" Possible unsafe locking scenario:\n\n");
printk(" CPU0 CPU1\n");
printk(" ---- ----\n");
printk(" lock(");
if (tgt_read != 0)
printk(" rlock(");
else
printk(" lock(");
__print_lock_name(target);
printk(KERN_CONT ");\n");
printk(" lock(");
@@ -1917,7 +1922,12 @@ print_circular_lock_scenario(struct held_lock *src,
printk(" lock(");
__print_lock_name(target);
printk(KERN_CONT ");\n");
printk(" lock(");
if (src_read != 0)
printk(" rlock(");
else if (src->sync)
printk(" sync(");
else
printk(" lock(");
__print_lock_name(source);
printk(KERN_CONT ");\n");
printk("\n *** DEADLOCK ***\n\n");
@@ -4531,7 +4541,13 @@ mark_usage(struct task_struct *curr, struct held_lock *hlock, int check)
return 0;
}
}
if (!hlock->hardirqs_off) {
/*
* For lock_sync(), don't mark the ENABLED usage, since lock_sync()
* creates no critical section and no extra dependency can be introduced
* by interrupts
*/
if (!hlock->hardirqs_off && !hlock->sync) {
if (hlock->read) {
if (!mark_lock(curr, hlock,
LOCK_ENABLED_HARDIRQ_READ))
@@ -4910,7 +4926,7 @@ static int __lock_is_held(const struct lockdep_map *lock, int read);
static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
int trylock, int read, int check, int hardirqs_off,
struct lockdep_map *nest_lock, unsigned long ip,
int references, int pin_count)
int references, int pin_count, int sync)
{
struct task_struct *curr = current;
struct lock_class *class = NULL;
@@ -4961,7 +4977,8 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
class_idx = class - lock_classes;
if (depth) { /* we're holding locks */
if (depth && !sync) {
/* we're holding locks and the new held lock is not a sync */
hlock = curr->held_locks + depth - 1;
if (hlock->class_idx == class_idx && nest_lock) {
if (!references)
@@ -4995,6 +5012,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
hlock->trylock = trylock;
hlock->read = read;
hlock->check = check;
hlock->sync = !!sync;
hlock->hardirqs_off = !!hardirqs_off;
hlock->references = references;
#ifdef CONFIG_LOCK_STAT
@@ -5056,6 +5074,10 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
if (!validate_chain(curr, hlock, chain_head, chain_key))
return 0;
/* For lock_sync(), we are done here since no actual critical section */
if (hlock->sync)
return 1;
curr->curr_chain_key = chain_key;
curr->lockdep_depth++;
check_chain_key(curr);
@@ -5197,7 +5219,7 @@ static int reacquire_held_locks(struct task_struct *curr, unsigned int depth,
hlock->read, hlock->check,
hlock->hardirqs_off,
hlock->nest_lock, hlock->acquire_ip,
hlock->references, hlock->pin_count)) {
hlock->references, hlock->pin_count, 0)) {
case 0:
return 1;
case 1:
@@ -5667,7 +5689,7 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
lockdep_recursion_inc();
__lock_acquire(lock, subclass, trylock, read, check,
irqs_disabled_flags(flags), nest_lock, ip, 0, 0);
irqs_disabled_flags(flags), nest_lock, ip, 0, 0, 0);
lockdep_recursion_finish();
raw_local_irq_restore(flags);
}
@@ -5693,6 +5715,34 @@ void lock_release(struct lockdep_map *lock, unsigned long ip)
}
EXPORT_SYMBOL_GPL(lock_release);
/*
* lock_sync() - A special annotation for synchronize_{s,}rcu()-like API.
*
* No actual critical section is created by the APIs annotated with this: these
* APIs are used to wait for one or multiple critical sections (on other CPUs
* or threads), and it means that calling these APIs inside these critical
* sections is potential deadlock.
*/
void lock_sync(struct lockdep_map *lock, unsigned subclass, int read,
int check, struct lockdep_map *nest_lock, unsigned long ip)
{
unsigned long flags;
if (unlikely(!lockdep_enabled()))
return;
raw_local_irq_save(flags);
check_flags(flags);
lockdep_recursion_inc();
__lock_acquire(lock, subclass, 0, read, check,
irqs_disabled_flags(flags), nest_lock, ip, 0, 0, 1);
check_chain_key(current);
lockdep_recursion_finish();
raw_local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(lock_sync);
noinstr int lock_is_held_type(const struct lockdep_map *lock, int read)
{
unsigned long flags;
kernel/locking/test-ww_mutex.c
+1 -1
View File
@@ -659,7 +659,7 @@ static int __init test_ww_mutex_init(void)
if (ret)
return ret;
ret = stress(4095, hweight32(STRESS_ALL)*ncpus, STRESS_ALL);
ret = stress(2047, hweight32(STRESS_ALL)*ncpus, STRESS_ALL);
if (ret)
return ret;