On 3/1/19 4:19 PM, Tycho Andersen wrote: > On Fri, Mar 01, 2019 at 04:16:27PM +0100, Michael Kerrisk (man-pages) wrote: >> Hello Tycho, >> >> On 3/1/19 3:53 PM, Tycho Andersen wrote: >>> On Thu, Feb 28, 2019 at 01:52:19PM +0100, Michael Kerrisk (man-pages) wrote: >>>>> +a notification will be sent to this fd. See "Userspace Notification" below for >>>> >>>> s/fd/file descriptor/ throughout please. >>> >>> Will do. >>> >>>>> +more details. >>>> >>>> I think the description here could be better worded as something like: >>>> >>>> SECCOMP_FILTER_FLAG_NEW_LISTENER >>>> Register a new filter, as usual, but on success return a >>>> new file descriptor that provides user-space notifications. >>>> When the filter returns SECCOMP_RET_USER_NOTIF, a notification >>>> will be provided via this file descriptor. The close-on-exec >>>> flag is automatically set on the new file descriptor. ... >>>> >>>>> .RE >>>>> .TP >>>>> .BR SECCOMP_GET_ACTION_AVAIL " (since Linux 4.14)" >>>>> @@ -606,6 +613,17 @@ file. >>>>> .TP >>>>> .BR SECCOMP_RET_ALLOW >>>>> This value results in the system call being executed. >>>>> +.TP >>>>> +.BR SECCOMP_RET_USER_NOTIF " (since Linux 4.21)" >>>> >>>> Please see the start of this hanging list in the manual page. >>>> Can you confirm that SECCOMP_RET_USER_NOTIF really is the lowest >>>> in the precedence order of all of the filter return values? >>> >>> Oh, no, I didn't realize it was in a particular order. I'll switch it. >> >> Just for my immediate education (I'm experimenting right now), >> where/how does it fit in the precedence order? > > In between RET_ERRNO and RET_TRACE; see include/uapi/linux/seccomp.h > for details. Confirmed by experiment :-). Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/
