[...] > > > > > > Even if a custom policy has been loaded, potentially additional > > > measurements unrelated to this test would be included the measurement > > > list. One way of limiting a rule to a specific test is by loopback > > > mounting a file system and defining a policy rule based on the loopback > > > mount unique uuid. > > > > Thanks Mimi! > > > > I wonder if we simply limit this to policy to /tmp and run an executable > > from /tmp (like test_local_storage.c does). > > > > The only side effect would be of extra hashes being calculated on > > binaries run from /tmp which is not too bad I guess? > > The builtin measurement policy (ima_policy=tcb") explicitly defines a > rule to not measure /tmp files. Measuring /tmp results in a lot of > measurements. > > {.action = DONT_MEASURE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC}, > > > > > We could do the loop mount too, but I am guessing the most clean way > > would be to shell out to mount from the test? Are there some other examples > > of IMA we could look at? > > LTP loopback mounts a filesystem, since /tmp is not being measured with > the builtin "tcb" policy. Defining new policy rules should be limited > to the loopback mount. This would pave the way for defining IMA- > appraisal signature verification policy rules, without impacting the > running system. +Andrii Do you think we can split the IMA test out, have a little shell script that does the loopback mount, gets the FS UUID, updates the IMA policy and then runs a C program? This would also allow "test_progs" to be independent of CONFIG_IMA. I am guessing the structure would be something similar to test_xdp_redirect.sh - KP > > Mimi >