[PATCH net-next 3/5] bpf: bpf_lock on kallsysms doesn't need to be irqsave

[Daniel Borkmann]

From: Hannes Frederic Sowa <han...@stressinduktion.org>

Hannes rightfully spotted that the bpf_lock doesn't need to be
irqsave variant. We never perform any such updates where this
would be necessary (neither right now nor in future), therefore
relax this further.

Signed-off-by: Hannes Frederic Sowa <han...@stressinduktion.org>
Signed-off-by: Daniel Borkmann <dan...@iogearbox.net>
Acked-by: Alexei Starovoitov <a...@kernel.org>
---
 kernel/bpf/core.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index b4f1cb0..6f81e0f 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -394,27 +394,23 @@ static bool bpf_prog_kallsyms_verify_off(const struct 
bpf_prog *fp)
 
 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
 {
-       unsigned long flags;
-
        if (!bpf_prog_kallsyms_candidate(fp) ||
            !capable(CAP_SYS_ADMIN))
                return;
 
-       spin_lock_irqsave(&bpf_lock, flags);
+       spin_lock_bh(&bpf_lock);
        bpf_prog_ksym_node_add(fp->aux);
-       spin_unlock_irqrestore(&bpf_lock, flags);
+       spin_unlock_bh(&bpf_lock);
 }
 
 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
 {
-       unsigned long flags;
-
        if (!bpf_prog_kallsyms_candidate(fp))
                return;
 
-       spin_lock_irqsave(&bpf_lock, flags);
+       spin_lock_bh(&bpf_lock);
        bpf_prog_ksym_node_del(fp->aux);
-       spin_unlock_irqrestore(&bpf_lock, flags);
+       spin_unlock_bh(&bpf_lock);
 }
 
 static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr)
-- 
1.9.3