netdev - [PATCH bpf] bpf, sysctl: let bpf_stats_handler take a kernel pointer buffer

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Date:   Mon, 24 Aug 2020 16:20:47 +0200
From:   Tobias Klauser <tklauser@...tanz.ch>
To:     Daniel Borkmann <daniel@...earbox.net>,
        Alexei Starovoitov <ast@...nel.org>
Cc:     Luis Chamberlain <mcgrof@...nel.org>,
        Kees Cook <keescook@...omium.org>,
        Iurii Zaikin <yzaikin@...gle.com>,
        linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        netdev@...r.kernel.org, bpf@...r.kernel.org,
        Christoph Hellwig <hch@....de>
Subject: [PATCH bpf] bpf, sysctl: let bpf_stats_handler take a kernel pointer buffer

Commit 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
changed ctl_table.proc_handler to take a kernel pointer. Adjust the
signature of bpf_stats_handler to match ctl_table.proc_handler which
fixes the following sparse warning:

kernel/sysctl.c:226:49: warning: incorrect type in argument 3 (different address spaces)
kernel/sysctl.c:226:49:    expected void *
kernel/sysctl.c:226:49:    got void [noderef] __user *buffer
kernel/sysctl.c:2640:35: warning: incorrect type in initializer (incompatible argument 3 (different address spaces))
kernel/sysctl.c:2640:35:    expected int ( [usertype] *proc_handler )( ... )
kernel/sysctl.c:2640:35:    got int ( * )( ... )

Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
Cc: Christoph Hellwig <hch@....de>
Signed-off-by: Tobias Klauser <tklauser@...tanz.ch>
---
 kernel/sysctl.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 287862f91717..09e70ee2332e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -204,8 +204,7 @@ static int max_extfrag_threshold = 1000;

 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_SYSCTL)
 static int bpf_stats_handler(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp,
-			     loff_t *ppos)
+			     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct static_key *key = (struct static_key *)table->data;
 	static int saved_val;
-- 
2.27.0