From: Alexei Starovoitov <ast@kernel.org>
Date: Thu, 24 Sep 2020 02:10:38 +0000 (-0700)
Subject: Revert "bpf: Fix potential call bpf_link_free() in atomic context"
X-Git-Tag: v5.10.7~1401^2~96^2~43
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f00f2f7fe86036a586e26bd55ad86310477199a3;p=platform%2Fkernel%2Flinux-rpi.git

Revert "bpf: Fix potential call bpf_link_free() in atomic context"

This reverts commit 31f23a6a181c81543b10a1a9056b0e6c7ef1c747.

This change made many selftests/bpf flaky: flow_dissector, sk_lookup, sk_assign and others.
There was no issue in the code.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 3426849..2740df1 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2345,8 +2345,12 @@ void bpf_link_put(struct bpf_link *link)
 	if (!atomic64_dec_and_test(&link->refcnt))
 		return;
 
-	INIT_WORK(&link->work, bpf_link_put_deferred);
-	schedule_work(&link->work);
+	if (in_atomic()) {
+		INIT_WORK(&link->work, bpf_link_put_deferred);
+		schedule_work(&link->work);
+	} else {
+		bpf_link_free(link);
+	}
 }
 
 static int bpf_link_release(struct inode *inode, struct file *filp)