Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Yafang Shao <laoar.shao@gmail.com>
To:     ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
        kafai@fb.com, songliubraving@fb.com, yhs@fb.com,
        john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
        haoluo@google.com, jolsa@kernel.org, rostedt@goodmis.org,
        mhiramat@kernel.org
Cc:     bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
        linux-kernel@vger.kernel.org, Yafang Shao <laoar.shao@gmail.com>
Subject: [PATCH bpf-next 6/6] bpf: Remove some denied functions from the btf id deny list
Date:   Mon, 17 Apr 2023 15:47:37 +0000
Message-Id: <20230417154737.12740-7-laoar.shao@gmail.com>
In-Reply-To: <20230417154737.12740-1-laoar.shao@gmail.com>
References: <20230417154737.12740-1-laoar.shao@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

With the generic tracing recursion prevention mechanism applied, it is
safe to trace migrate_{disable,enable} and preempt_count_{sub,add}. So
we can remove them from the deny list.
However we can't remove rcu_read_unlock_strict and
__rcu_read_{lock,unlock}, because they are used in rcu_read_unlock() or
rcu_read_lock().

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
 kernel/bpf/verifier.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 83fb94f..40f6b2c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -18634,17 +18634,9 @@ int bpf_check_attach_target(struct bpf_verifier_log *log,
 
 BTF_SET_START(btf_id_deny)
 BTF_ID_UNUSED
-#ifdef CONFIG_SMP
-BTF_ID(func, migrate_disable)
-BTF_ID(func, migrate_enable)
-#endif
 #if !defined CONFIG_PREEMPT_RCU && !defined CONFIG_TINY_RCU
 BTF_ID(func, rcu_read_unlock_strict)
 #endif
-#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_TRACE_PREEMPT_TOGGLE)
-BTF_ID(func, preempt_count_add)
-BTF_ID(func, preempt_count_sub)
-#endif
 #ifdef CONFIG_PREEMPT_RCU
 BTF_ID(func, __rcu_read_lock)
 BTF_ID(func, __rcu_read_unlock)
-- 
1.8.3.1