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-rw-r--r--include/linux/mmap_lock.h9
-rw-r--r--kernel/bpf/stackmap.c10
2 files changed, 8 insertions, 11 deletions
diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
index 0540f0156f58..3af8f7fb067d 100644
--- a/include/linux/mmap_lock.h
+++ b/include/linux/mmap_lock.h
@@ -144,15 +144,6 @@ static inline void mmap_read_unlock(struct mm_struct *mm)
__mmap_lock_trace_released(mm, false);
}
-static inline bool mmap_read_trylock_non_owner(struct mm_struct *mm)
-{
- if (mmap_read_trylock(mm)) {
- rwsem_release(&mm->mmap_lock.dep_map, _RET_IP_);
- return true;
- }
- return false;
-}
-
static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
{
up_read_non_owner(&mm->mmap_lock);
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index e8eefdf8cf3e..09a3fd97d329 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -179,7 +179,7 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs,
* with build_id.
*/
if (!user || !current || !current->mm || irq_work_busy ||
- !mmap_read_trylock_non_owner(current->mm)) {
+ !mmap_read_trylock(current->mm)) {
/* cannot access current->mm, fall back to ips */
for (i = 0; i < trace_nr; i++) {
id_offs[i].status = BPF_STACK_BUILD_ID_IP;
@@ -204,9 +204,15 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs,
}
if (!work) {
- mmap_read_unlock_non_owner(current->mm);
+ mmap_read_unlock(current->mm);
} else {
work->mm = current->mm;
+
+ /* The lock will be released once we're out of interrupt
+ * context. Tell lockdep that we've released it now so
+ * it doesn't complain that we forgot to release it.
+ */
+ rwsem_release(&current->mm->mmap_lock.dep_map, _RET_IP_);
irq_work_queue(&work->irq_work);
}
}