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authorIngo Molnar <mingo@kernel.org>2019-12-30 08:10:51 +0100
committerIngo Molnar <mingo@kernel.org>2019-12-30 08:10:51 +0100
commit28336be568bb473d16ba80db0801276fb4f1bbe5 (patch)
treecf2d7a56e6c3ea08139d8d9a5a58b296bd172136 /kernel/bpf/stackmap.c
parent5cbaefe9743bf14c9d3106db0cc19f8cb0a3ca22 (diff)
parentfd6988496e79a6a4bdb514a4655d2920209eb85d (diff)
downloadcachepc-linux-28336be568bb473d16ba80db0801276fb4f1bbe5.tar.gz
cachepc-linux-28336be568bb473d16ba80db0801276fb4f1bbe5.zip
Merge tag 'v5.5-rc4' into locking/kcsan, to resolve conflicts
Conflicts: init/main.c lib/Kconfig.debug Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/bpf/stackmap.c')
-rw-r--r--kernel/bpf/stackmap.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index 052580c33d26..3f958b90d914 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -287,16 +287,17 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs,
bool irq_work_busy = false;
struct stack_map_irq_work *work = NULL;
- if (in_nmi()) {
+ if (irqs_disabled()) {
work = this_cpu_ptr(&up_read_work);
- if (work->irq_work.flags & IRQ_WORK_BUSY)
+ if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY)
/* cannot queue more up_read, fallback */
irq_work_busy = true;
}
/*
- * We cannot do up_read() in nmi context. To do build_id lookup
- * in nmi context, we need to run up_read() in irq_work. We use
+ * We cannot do up_read() when the irq is disabled, because of
+ * risk to deadlock with rq_lock. To do build_id lookup when the
+ * irqs are disabled, we need to run up_read() in irq_work. We use
* a percpu variable to do the irq_work. If the irq_work is
* already used by another lookup, we fall back to report ips.
*
@@ -338,7 +339,7 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs,
* up_read_non_owner(). The rwsem_release() is called
* here to release the lock from lockdep's perspective.
*/
- rwsem_release(&current->mm->mmap_sem.dep_map, 1, _RET_IP_);
+ rwsem_release(&current->mm->mmap_sem.dep_map, _RET_IP_);
}
}