[PATCH 5.4 047/183] bpf: Factor out bpf_spin_lock into helpers.

Sasha Levin
2024-03-24T23:47:27Z

From: Alexei Starovoitov <ast@kernel.org>

[ Upstream commit c1b3fed319d32a721d4b9c17afaeb430444ff773 ]

Move ____bpf_spin_lock/unlock into helpers to make it more clear
that quadruple underscore bpf_spin_lock/unlock are irqsave/restore variants.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210715005417.78572-3-alexei.starovoitov@gmail.com
Stable-dep-of: 178c54666f9c ("bpf: Mark bpf_spin_{lock,unlock}() helpers with notrace correctly")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/bpf/helpers.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index a77d2814cac5d..4ba3dc621a345 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -262,13 +262,18 @@ static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)

static DEFINE_PER_CPU(unsigned long, irqsave_flags);

-notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
+static inline void __bpf_spin_lock_irqsave(struct bpf_spin_lock *lock)
{
unsigned long flags;

local_irq_save(flags);
__bpf_spin_lock(lock);
__this_cpu_write(irqsave_flags, flags);
+}
+
+notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
+{
+ __bpf_spin_lock_irqsave(lock);
return 0;
}

@@ -279,13 +284,18 @@ const struct bpf_func_proto bpf_spin_lock_proto = {
.arg1_type = ARG_PTR_TO_SPIN_LOCK,
};

-notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
+static inline void __bpf_spin_unlock_irqrestore(struct bpf_spin_lock *lock)
{
unsigned long flags;

flags = __this_cpu_read(irqsave_flags);
__bpf_spin_unlock(lock);
local_irq_restore(flags);
+}
+
+notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
+{
+ __bpf_spin_unlock_irqrestore(lock);
return 0;
}

@@ -306,9 +316,9 @@ void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
else
lock = dst + map->spin_lock_off;
preempt_disable();
- ____bpf_spin_lock(lock);
+ __bpf_spin_lock_irqsave(lock);
copy_map_value(map, dst, src);
- ____bpf_spin_unlock(lock);
+ __bpf_spin_unlock_irqrestore(lock);
preempt_enable();
}

--
2.43.0