On Tue, Mar 16, 2021 at 09:42:50PM +0100, Mickaël Salaün wrote: > From: Mickaël Salaün <[email protected]> > > Test all Landlock system calls, ptrace hooks semantic and filesystem > access-control with multiple layouts. > > Test coverage for security/landlock/ is 93.6% of lines. The code not > covered only deals with internal kernel errors (e.g. memory allocation) > and race conditions. > > Cc: James Morris <[email protected]> > Cc: Jann Horn <[email protected]> > Cc: Kees Cook <[email protected]> > Cc: Serge E. Hallyn <[email protected]> > Cc: Shuah Khan <[email protected]> > Signed-off-by: Mickaël Salaün <[email protected]> > Reviewed-by: Vincent Dagonneau <[email protected]> > Link: https://lore.kernel.org/r/[email protected]
This is terrific. I love the coverage. How did you measure this, BTW? To increase it into memory allocation failures, have you tried allocation fault injection: https://www.kernel.org/doc/html/latest/fault-injection/fault-injection.html > [...] > +TEST(inconsistent_attr) { > + const long page_size = sysconf(_SC_PAGESIZE); > + char *const buf = malloc(page_size + 1); > + struct landlock_ruleset_attr *const ruleset_attr = (void *)buf; > + > + ASSERT_NE(NULL, buf); > + > + /* Checks copy_from_user(). */ > + ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 0, 0)); > + /* The size if less than sizeof(struct landlock_attr_enforce). */ > + ASSERT_EQ(EINVAL, errno); > + ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 1, 0)); > + ASSERT_EQ(EINVAL, errno); Almost everywhere you're using ASSERT instead of EXPECT. Is this correct (in the sense than as soon as an ASSERT fails the rest of the test is skipped)? I do see you using EXPECT is some places, but I figured I'd ask about the intention here. > +/* > + * TEST_F_FORK() is useful when a test drop privileges but the corresponding > + * FIXTURE_TEARDOWN() requires them (e.g. to remove files from a directory > + * where write actions are denied). For convenience, FIXTURE_TEARDOWN() is > + * also called when the test failed, but not when FIXTURE_SETUP() failed. > For > + * this to be possible, we must not call abort() but instead exit smoothly > + * (hence the step print). > + */ Hm, interesting. I think this should be extracted into a separate patch and added to the test harness proper. Could this be solved with TEARDOWN being called on SETUP failure? > +#define TEST_F_FORK(fixture_name, test_name) \ > + static void fixture_name##_##test_name##_child( \ > + struct __test_metadata *_metadata, \ > + FIXTURE_DATA(fixture_name) *self, \ > + const FIXTURE_VARIANT(fixture_name) *variant); \ > + TEST_F(fixture_name, test_name) \ > + { \ > + int status; \ > + const pid_t child = fork(); \ > + if (child < 0) \ > + abort(); \ > + if (child == 0) { \ > + _metadata->no_print = 1; \ > + fixture_name##_##test_name##_child(_metadata, self, > variant); \ > + if (_metadata->skip) \ > + _exit(255); \ > + if (_metadata->passed) \ > + _exit(0); \ > + _exit(_metadata->step); \ > + } \ > + if (child != waitpid(child, &status, 0)) \ > + abort(); \ > + if (WIFSIGNALED(status) || !WIFEXITED(status)) { \ > + _metadata->passed = 0; \ > + _metadata->step = 1; \ > + return; \ > + } \ > + switch (WEXITSTATUS(status)) { \ > + case 0: \ > + _metadata->passed = 1; \ > + break; \ > + case 255: \ > + _metadata->passed = 1; \ > + _metadata->skip = 1; \ > + break; \ > + default: \ > + _metadata->passed = 0; \ > + _metadata->step = WEXITSTATUS(status); \ > + break; \ > + } \ > + } \ This looks like a subset of __wait_for_test()? Could __TEST_F_IMPL() be updated instead to do this? (Though the fork overhead might not be great for everyone.) -- Kees Cook
