On 2023-01-27 16:03, Jens Axboe wrote:
> On 1/27/23 4:02 PM, Richard Guy Briggs wrote:
> > On 2023-01-27 15:45, Jens Axboe wrote:
> >> On 1/27/23 3:35?PM, Paul Moore wrote:
> >>> On Fri, Jan 27, 2023 at 12:24 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> >>>>
> >>>> Since FADVISE can truncate files and MADVISE operates on memory, reverse
> >>>> the audit_skip tags.
> >>>>
> >>>> Fixes: 5bd2182d58e9 ("audit,io_uring,io-wq: add some basic audit support to io_uring")
> >>>> Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> >>>> ---
> >>>> io_uring/opdef.c | 2 +-
> >>>> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>>>
> >>>> diff --git a/io_uring/opdef.c b/io_uring/opdef.c
> >>>> index 3aa0d65c50e3..a2bf53b4a38a 100644
> >>>> --- a/io_uring/opdef.c
> >>>> +++ b/io_uring/opdef.c
> >>>> @@ -306,12 +306,12 @@ const struct io_op_def io_op_defs[] = {
> >>>> },
> >>>> [IORING_OP_FADVISE] = {
> >>>> .needs_file = 1,
> >>>> - .audit_skip = 1,
> >>>> .name = "FADVISE",
> >>>> .prep = io_fadvise_prep,
> >>>> .issue = io_fadvise,
> >>>> },
> >>>
> >>> I've never used posix_fadvise() or the associated fadvise64*()
> >>> syscalls, but from quickly reading the manpages and the
> >>> generic_fadvise() function in the kernel I'm missing where the fadvise
> >>> family of functions could be used to truncate a file, can you show me
> >>> where this happens? The closest I can see is the manipulation of the
> >>> page cache, but that shouldn't actually modify the file ... right?
> >>
> >> Yeah, honestly not sure where that came from. Maybe it's being mixed up
> >> with fallocate? All fadvise (or madvise, for that matter) does is
> >> provide hints on the caching or access pattern. On second thought, both
> >> of these should be able to set audit_skip as far as I can tell.
> >
> > That was one suspicion I had. If this is the case, I'd agree both could
> > be skipped.
>
> I'd be surprised if Steve didn't mix them up. Once he responds, can you
> send a v2 with the correction?
Gladly.
> Jens Axboe
- RGB
--
Richard Guy Briggs <rgb@xxxxxxxxxx>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635
