From: Paolo Bonzini <pbonzini@redhat.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Thomas Huth <thuth@redhat.com>,
"P. Berrange, Daniel" <berrange@redhat.com>,
qemu-devel@nongnu.org, vgoyal@redhat.com
Subject: Re: libcap vs libcap-ng mess
Date: Mon, 2 Dec 2019 11:33:29 +0100 [thread overview]
Message-ID: <7f8d4bf2-1a75-efa4-4c3f-e774d761b872@redhat.com> (raw)
In-Reply-To: <20191202100731.GB2904@work-vm>
On 02/12/19 11:07, Dr. David Alan Gilbert wrote:
> * Paolo Bonzini (pbonzini@redhat.com) wrote:
>> Il ven 29 nov 2019, 19:54 Dr. David Alan Gilbert <dgilbert@redhat.com> ha
>> scritto:
>>
>>>> Yes, it's per thread. The state can be built from
>>>> capng_clear/capng_get_caps_process + capng_update, and left in there
>>>> forever. There is also capng_save_state/capng_restore_state which, as
>>>> far as I can see from the sources, can be used across threads.
>>>
>>> So, I think what you're saying is I need to:
>>> a) Before we sandbox do the capng_get_caps_process
>>>
>>
>> Why not after sandboxing?
>
> Because in our sandbox we don't have /proc and capng_get_caps_process
> tries to read /proc/.../status and fails. The old libcap code doesn't
> use /proc, it just uses capget (which the new one also uses).
"In the middle of sandboxing" would have been a more precise suggestion.
In the virtio-9p proxy I set up the state right after the sandboxing
capng_apply, so that there is no need to do capng_get_caps_process (the
libcap virtio-9p also used cap_get_proc). So you could capng_save_state
there.
Paolo
prev parent reply other threads:[~2019-12-02 10:34 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-28 19:04 libcap vs libcap-ng mess Dr. David Alan Gilbert
2019-11-29 9:34 ` Daniel P. Berrangé
2019-11-29 10:46 ` Paolo Bonzini
2019-11-29 10:51 ` Dr. David Alan Gilbert
2019-11-29 18:01 ` Dr. David Alan Gilbert
2019-11-29 18:12 ` Paolo Bonzini
2019-11-29 18:20 ` Dr. David Alan Gilbert
2019-11-29 18:27 ` Paolo Bonzini
2019-11-29 18:54 ` Dr. David Alan Gilbert
2019-11-29 23:19 ` Paolo Bonzini
2019-12-02 10:07 ` Dr. David Alan Gilbert
2019-12-02 10:33 ` Paolo Bonzini [this message]
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