lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Wed, 30 Sep 2020 22:35:01 -0700
From:   Alexei Starovoitov <alexei.starovoitov@...il.com>
To:     bimmy.pujari@...el.com
Cc:     bpf@...r.kernel.org, netdev@...r.kernel.org, mchehab@...nel.org,
        ast@...nel.org, daniel@...earbox.net, kafai@...com,
        maze@...gle.com, ashkan.nikravesh@...el.com,
        Daniel.A.Alvarez@...el.com
Subject: Re: [PATCH bpf-next v7 2/2] selftests/bpf: Selftest for real time
 helper

On Wed, Sep 30, 2020 at 07:05:04PM -0700, bimmy.pujari@...el.com wrote:
> +SEC("realtime_helper")
> +int realtime_helper_test(struct __sk_buff *skb)
> +{
> +	unsigned long long *lasttime;
> +	unsigned long long curtime;
> +	int key = 0;
> +	int err = 0;
> +
> +	lasttime = bpf_map_lookup_elem(&time_map, &key);
> +	if (!lasttime)
> +		goto err;
> +
> +	curtime = bpf_ktime_get_real_ns();
> +	if (curtime <= *lasttime) {
> +		err = 1;
> +		goto err;
> +	}
> +	*lasttime = curtime;

so the test is doing exactly what comment in patch 1 is saying not to do.
I'm sorry but Andrii's comments are correct. If the authors of the patch
cannot make it right we should not add this helper to general audience.
Just because POSIX allows it it doesn't mean that it did the good choice.

Powered by blists - more mailing lists