From: Joel Fernandes <joel@joelfernandes.org>
To: Amol Grover <frextrite@gmail.com>
Cc: Paul Moore <paul@paul-moore.com>,
linux-kernel@vger.kernel.org, Eric Paris <eparis@redhat.com>,
linux-audit@redhat.com,
linux-kernel-mentees@lists.linuxfoundation.org
Subject: Re: [Linux-kernel-mentees] [PATCH] kernel: audit.c: Add __rcu notation to RCU pointer
Date: Tue, 26 Nov 2019 21:29:25 -0500 [thread overview]
Message-ID: <20191127022925.GB157739@google.com> (raw)
In-Reply-To: <20191126172723.GA12759@workstation-kernel-dev>
On Tue, Nov 26, 2019 at 10:57:23PM +0530, Amol Grover wrote:
> add __rcu notation to RCU protected global pointer auditd_conn
>
> Fixes multiple instances of sparse error:
> error: incompatible types in comparison expression
> (different address spaces)
>
> Signed-off-by: Amol Grover <frextrite@gmail.com>
> ---
> kernel/audit.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/audit.c b/kernel/audit.c
> index da8dc0db5bd3..30e7fc9b8da2 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -102,12 +102,14 @@ struct audit_net {
> * This struct is RCU protected; you must either hold the RCU lock for reading
> * or the associated spinlock for writing.
> */
> -static struct auditd_connection {
> +struct auditd_connection {
> struct pid *pid;
> u32 portid;
> struct net *net;
> struct rcu_head rcu;
> -} *auditd_conn = NULL;
> +};
> +static struct auditd_connection __rcu *auditd_conn;
> +RCU_INIT_POINTER(auditd_conn);
Looks like this causes a build error. Always please build test your patches
in the very least. And I also did not understand how RCU_INIT_POINTER can
even be used outside of a function. In C, executable code cannot be outside
functions.
Is doing the following not sufficient to fix the sparse issue?
thanks,
- Joel
---8<-----------------------
diff --git a/kernel/audit.c b/kernel/audit.c
index 49b6049b26ac..c5d4b5a2dea1 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -108,8 +108,8 @@ struct auditd_connection {
struct net *net;
struct rcu_head rcu;
};
-static struct auditd_connection __rcu *auditd_conn;
-RCU_INIT_POINTER(auditd_conn);
+static struct auditd_connection __rcu *auditd_conn = NULL;
+
static DEFINE_SPINLOCK(auditd_conn_lock);
/* If audit_rate_limit is non-zero, limit the rate of sending audit records
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next prev parent reply other threads:[~2019-11-27 2:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-26 17:27 [Linux-kernel-mentees] [PATCH] kernel: audit.c: Add __rcu notation to RCU pointer Amol Grover
2019-11-27 2:29 ` Joel Fernandes [this message]
2019-11-27 5:28 ` Amol Grover
2019-11-27 15:25 ` Joel Fernandes
2019-11-28 15:09 ` Amol Grover
2019-11-29 20:08 ` Joel Fernandes
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