diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2025-09-22 16:09:17 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-10-29 10:29:57 +0100 |
| commit | 639214f65b1db87c6992eadf93079ff0d8768c2d (patch) | |
| tree | 7254bb68b382ea47e8555af40c53065de5c4b2b7 /kernel | |
| parent | 42b9138f81fc22c36128f9524bb21bc9eabfb1b8 (diff) | |
unwind: Make unwind_task_info::unwind_mask consistent
The unwind_task_info::unwind_mask was manipulated using a mixture of:
regular store
WRITE_ONCE()
try_cmpxchg()
set_bit()
atomic_long_*()
Clean up and make it consistently atomic_long_t.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20250924080119.384384486@infradead.org
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/unwind/deferred.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/kernel/unwind/deferred.c b/kernel/unwind/deferred.c index 09617d8ae24b..a88fb481c4a3 100644 --- a/kernel/unwind/deferred.c +++ b/kernel/unwind/deferred.c @@ -53,7 +53,7 @@ DEFINE_STATIC_SRCU(unwind_srcu); static inline bool unwind_pending(struct unwind_task_info *info) { - return test_bit(UNWIND_PENDING_BIT, &info->unwind_mask); + return atomic_long_read(&info->unwind_mask) & UNWIND_PENDING; } /* @@ -141,7 +141,7 @@ int unwind_user_faultable(struct unwind_stacktrace *trace) cache->nr_entries = trace->nr; /* Clear nr_entries on way back to user space */ - set_bit(UNWIND_USED_BIT, &info->unwind_mask); + atomic_long_or(UNWIND_USED, &info->unwind_mask); return 0; } @@ -159,7 +159,7 @@ static void process_unwind_deferred(struct task_struct *task) /* Clear pending bit but make sure to have the current bits */ bits = atomic_long_fetch_andnot(UNWIND_PENDING, - (atomic_long_t *)&info->unwind_mask); + &info->unwind_mask); /* * From here on out, the callback must always be called, even if it's * just an empty trace. @@ -264,7 +264,7 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie) *cookie = get_cookie(info); - old = READ_ONCE(info->unwind_mask); + old = atomic_long_read(&info->unwind_mask); /* Is this already queued or executed */ if (old & bit) @@ -277,7 +277,7 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie) * to have a callback. */ bits = UNWIND_PENDING | bit; - old = atomic_long_fetch_or(bits, (atomic_long_t *)&info->unwind_mask); + old = atomic_long_fetch_or(bits, &info->unwind_mask); if (old & bits) { /* * If the work's bit was set, whatever set it had better @@ -291,7 +291,7 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie) ret = task_work_add(current, &info->work, twa_mode); if (WARN_ON_ONCE(ret)) - WRITE_ONCE(info->unwind_mask, 0); + atomic_long_set(&info->unwind_mask, 0); return ret; } @@ -323,7 +323,8 @@ void unwind_deferred_cancel(struct unwind_work *work) guard(rcu)(); /* Clear this bit from all threads */ for_each_process_thread(g, t) { - clear_bit(bit, &t->unwind_info.unwind_mask); + atomic_long_andnot(BIT(bit), + &t->unwind_info.unwind_mask); if (t->unwind_info.cache) clear_bit(bit, &t->unwind_info.cache->unwind_completed); } @@ -353,7 +354,7 @@ void unwind_task_init(struct task_struct *task) memset(info, 0, sizeof(*info)); init_task_work(&info->work, unwind_deferred_task_work); - info->unwind_mask = 0; + atomic_long_set(&info->unwind_mask, 0); } void unwind_task_free(struct task_struct *task) |