Re: [PATCH v1 1/2] io_uring,audit: audit IORING_OP_FADVISE but not IORING_OP_MADVISE

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(a)redhat.com&gt; 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(a)redhat.com&gt; >>>> --- >>>> 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?

Jens Axboe