[PATCH v6 6/9] seccomp: add "seccomp" syscall

[Kees Cook]

On Fri, Jun 13, 2014 at 2:22 PM, Alexei Starovoitov <ast at plumgrid.com> wrote:
> On Tue, Jun 10, 2014 at 8:25 PM, Kees Cook <keescook at chromium.org> wrote:
>> This adds the new "seccomp" syscall with both an "operation" and "flags"
>> parameter for future expansion. The third argument is a pointer value,
>> used with the SECCOMP_SET_MODE_FILTER operation. Currently, flags must
>> be 0. This is functionally equivalent to prctl(PR_SET_SECCOMP, ...).
>>
>> Signed-off-by: Kees Cook <keescook at chromium.org>
>> Cc: linux-api at vger.kernel.org
>> ---
>> diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
>> index b0881a0ed322..1713977ee26f 100644
>> --- a/include/linux/syscalls.h
>> +++ b/include/linux/syscalls.h
>> @@ -866,4 +866,6 @@ asmlinkage long sys_process_vm_writev(pid_t pid,
>>  asmlinkage long sys_kcmp(pid_t pid1, pid_t pid2, int type,
>>                          unsigned long idx1, unsigned long idx2);
>>  asmlinkage long sys_finit_module(int fd, const char __user *uargs, int flags);
>> +asmlinkage long sys_seccomp(unsigned int op, unsigned int flags,
>> +                           const char __user *uargs);
>
> It looks odd to add 'flags' argument to syscall that is not even used.

FWIW, "flags" is given use in the next patch to support the tsync option.

-Kees

-- 
Kees Cook
Chrome OS Security