Re: [PATCH 3/7] seccomp_filter: Enable ftrace-based system call filtering

From: Will Drewry
Date: Thu Apr 28 2011 - 12:53:25 EST


On Thu, Apr 28, 2011 at 11:28 AM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> On Wed, 2011-04-27 at 22:08 -0500, Will Drewry wrote:
>
>> The only other twist is that it is possible to delay enforcement by one
>> system call by supplying a "on_next_syscall: 1" 'filter'.  This allows
>> for a launcher process to fork(), prctl(), then execve() leaving the
>> launched binary in a filtered state.
>
> I wonder if the more "unixy" thing to do is, instead of on_next_sycall,
> have "enable_on_exec". Where the user could do multiple syscalls but the
> filter will not take place until an exec is made?

That's what it was originally, but since ftrace syscalls doesn't wrap
sys_execve on x86, I opted to just say "next syscall". But of course
I can just check the _NR_execve == syscall_nr and do the right thing.
Duh.

thanks!
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