diff options
Diffstat (limited to 'kernel/unwind/deferred.c')
| -rw-r--r-- | kernel/unwind/deferred.c | 44 |
1 files changed, 24 insertions, 20 deletions
diff --git a/kernel/unwind/deferred.c b/kernel/unwind/deferred.c index dc6040aae3ee..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; } /* @@ -79,6 +79,8 @@ static u64 get_cookie(struct unwind_task_info *info) { u32 cnt = 1; + lockdep_assert_irqs_disabled(); + if (info->id.cpu) return info->id.id; @@ -126,23 +128,20 @@ int unwind_user_faultable(struct unwind_stacktrace *trace) cache = info->cache; trace->entries = cache->entries; - - if (cache->nr_entries) { - /* - * The user stack has already been previously unwound in this - * entry context. Skip the unwind and use the cache. - */ - trace->nr = cache->nr_entries; + trace->nr = cache->nr_entries; + /* + * The user stack has already been previously unwound in this + * entry context. Skip the unwind and use the cache. + */ + if (trace->nr) return 0; - } - trace->nr = 0; unwind_user(trace, UNWIND_MAX_ENTRIES); 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; } @@ -160,7 +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. @@ -231,6 +230,7 @@ void unwind_deferred_task_exit(struct task_struct *task) int unwind_deferred_request(struct unwind_work *work, u64 *cookie) { struct unwind_task_info *info = ¤t->unwind_info; + int twa_mode = TWA_RESUME; unsigned long old, bits; unsigned long bit; int ret; @@ -246,8 +246,11 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie) * Trigger a warning to make it obvious that an architecture * is using this in NMI when it should not be. */ - if (WARN_ON_ONCE(!CAN_USE_IN_NMI && in_nmi())) - return -EINVAL; + if (in_nmi()) { + if (WARN_ON_ONCE(!CAN_USE_IN_NMI)) + return -EINVAL; + twa_mode = TWA_NMI_CURRENT; + } /* Do not allow cancelled works to request again */ bit = READ_ONCE(work->bit); @@ -261,7 +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) @@ -274,7 +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 @@ -285,10 +288,10 @@ int unwind_deferred_request(struct unwind_work *work, u64 *cookie) } /* The work has been claimed, now schedule it. */ - ret = task_work_add(current, &info->work, TWA_RESUME); + 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; } @@ -320,7 +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); } @@ -350,7 +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) |