Re: [PATCH] tls: don't abort the connection on signal-interrupted sends

[Jakub Kicinski <kuba@kernel.org>]

On Mon, 20 Jul 2026 11:08:47 +0200 Maximilian Immanuel Brandtner wrote:
> When a signal interrupts a blocking send, tls_tx_records() treats the
> resulting -ERESTARTSYS as a transmission failure and marks the socket
> errored via tls_err_abort() with the raw error code. Later syscalls
> return the kernel-internal errno 512 (ERESTARTSYS) to userspace, as the
> signal it stems from is no longer pending during syscall exit and thus
> never translated.

Can we just add ERESTARTSYS handling? I never heard of the other codes
you're checking TBH, can they actually surface?

> An interrupted send is not a connection error: the partially sent record
> stays queued and is resent later. Interrupt error codes are therefore
> excluded from the abort in the same way as -EAGAIN.
> 
> Fixes: b341ca51d267 ("tls: Fix tls_sw_sendmsg error handling")
> Signed-off-by: Maximilian Immanuel Brandtner <maxbr@linux.ibm.com>
> ---
> Tested on top of net commit 3f1f75536668 ("net: openvswitch: reject
> oversized nested action attrs").
> 
> Several subsystems contain static helper functions to classify these
> interrupt errnos. It might be worthwhile to refactor these static
> functions into a generic helper function.

Yes, please.

> diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
> index d4afc90fd796..3c9e94069e82 100644
> --- a/net/tls/tls_sw.c
> +++ b/net/tls/tls_sw.c
> @@ -405,6 +405,24 @@ static void tls_free_open_rec(struct sock *sk)
>  	}
>  }
>  
> +static bool tls_is_non_restartable_err(int err)
> +{
> +	if (err >= 0)
> +		return false;

This doesn't belong in a helper for classifying errors.

> +	switch (err) {
> +	case -EAGAIN:
> +	case -EINTR:
> +	case -ERESTARTSYS:
> +	case -ERESTARTNOINTR:
> +	case -ERESTARTNOHAND:
> +	case -ERESTART_RESTARTBLOCK:
> +		return false;
> +	default:
> +		return true;
> +	}
> +}
> +
>  int tls_tx_records(struct sock *sk, int flags)
>  {
>  	struct tls_context *tls_ctx = tls_get_ctx(sk);
> @@ -458,7 +476,7 @@ int tls_tx_records(struct sock *sk, int flags)
>  	}
>  
>  tx_err:
> -	if (rc < 0 && rc != -EAGAIN)
> +	if (tls_is_non_restartable_err(rc))
>  		tls_err_abort(sk, rc);
>  
>  	return rc;
-- 
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