| Message ID | 1463618533-7098-1-git-send-email-stefanha@redhat.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Stefan Hajnoczi <stefanha@redhat.com> Date: Wed, 18 May 2016 17:42:13 -0700 > The sk_err and sk_err_soft fields are positive errno values and > userspace applications rely on this when using getsockopt(SO_ERROR). > > ATM code places an -errno into sk_err_soft in sigd_send() and returns it > from svc_addparty()/svc_dropparty(). > > Although I am not familiar with ATM code I came to this conclusion > because: ... > This patch ensures that sk_err_soft is always a positive errno. > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > --- > This patch is untested and potentially affects the getsockopt(SO_ERROR) ABI for > a specific case in ATM. I leave it to the maintainer to decide whether this > inconsistency should be fixed or not. This looks fine, applied, thanks.
diff --git a/net/atm/signaling.c b/net/atm/signaling.c index 4fd6af4..adb6e3d 100644 --- a/net/atm/signaling.c +++ b/net/atm/signaling.c @@ -124,7 +124,7 @@ as_indicate_complete: break; case as_addparty: case as_dropparty: - sk->sk_err_soft = msg->reply; + sk->sk_err_soft = -msg->reply; /* < 0 failure, otherwise ep_ref */ clear_bit(ATM_VF_WAITING, &vcc->flags); break; diff --git a/net/atm/svc.c b/net/atm/svc.c index 3fa0a9e..878563a 100644 --- a/net/atm/svc.c +++ b/net/atm/svc.c @@ -546,7 +546,7 @@ static int svc_addparty(struct socket *sock, struct sockaddr *sockaddr, schedule(); } finish_wait(sk_sleep(sk), &wait); - error = xchg(&sk->sk_err_soft, 0); + error = -xchg(&sk->sk_err_soft, 0); out: release_sock(sk); return error; @@ -573,7 +573,7 @@ static int svc_dropparty(struct socket *sock, int ep_ref) error = -EUNATCH; goto out; } - error = xchg(&sk->sk_err_soft, 0); + error = -xchg(&sk->sk_err_soft, 0); out: release_sock(sk); return error;
The sk_err and sk_err_soft fields are positive errno values and userspace applications rely on this when using getsockopt(SO_ERROR). ATM code places an -errno into sk_err_soft in sigd_send() and returns it from svc_addparty()/svc_dropparty(). Although I am not familiar with ATM code I came to this conclusion because: 1. sigd_send() msg->type cases as_okay and as_error both have: sk->sk_err = -msg->reply; while the as_addparty and as_dropparty cases have: sk->sk_err_soft = msg->reply; This is the source of the inconsistency. 2. svc_addparty() returns an -errno and assumes sk_err_soft is also an -errno: if (flags & O_NONBLOCK) { error = -EINPROGRESS; goto out; } ... error = xchg(&sk->sk_err_soft, 0); out: release_sock(sk); return error; This shows that sk_err_soft is indeed being treated as an -errno. This patch ensures that sk_err_soft is always a positive errno. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- This patch is untested and potentially affects the getsockopt(SO_ERROR) ABI for a specific case in ATM. I leave it to the maintainer to decide whether this inconsistency should be fixed or not. net/atm/signaling.c | 2 +- net/atm/svc.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)